aboveground coarse wood: Topics by Science.gov

Sample records for aboveground coarse wood

Amazon forest carbon dynamics predicted by profiles of canopy leaf area and light environment

Treesearch

S. C. Stark; V. Leitold; J. L. Wu; M. O. Hunter; C. V. de Castilho; F. R. C. Costa; S. M. McMahon; G. G. Parker; M. Takako Shimabukuro; M. A. Lefsky; M. Keller; L. F. Alves; J. Schietti; Y. E. Shimabukuro; D. O. Brandao; T. K. Woodcock; N. Higuchi; P. B de Camargo; R. C. de Oliveira; S. R. Saleska

2012-01-01

Tropical forest structural variation across heterogeneous landscapes may control above-ground carbon dynamics. We tested the hypothesis that canopy structure (leaf area and light availability) â remotely estimated from LiDAR â control variation in above-ground coarse wood production (biomass growth). Using a statistical model, these factors predicted biomass growth...
Phloem Girdling of Norway Spruce Alters Quantity and Quality of Wood Formation in Roots Particularly Under Drought

PubMed Central

Rainer-Lethaus, Gina; Oberhuber, Walter

2018-01-01

Carbon (C) availability plays an essential role in tree growth and wood formation. We evaluated the hypothesis that a decrease in C availability (i) triggers mobilization of C reserves in the coarse roots of Picea abies to maintain growth and (ii) causes modification of wood structure notably under drought. The 6-year-old saplings were subjected to two levels of soil moisture (watered versus drought conditions) and root C status was manipulated by physically blocking phloem transport in the stem at three girdling dates (GDs). Stem girdling was done before the onset of bud break [day of the year (doy) 77], during vigorous aboveground shoot and radial stem growth (GD doy 138), and after cessation of shoot growth (GD doy 190). The effect of blockage of C transport on root growth, root phenology, and wood anatomical traits [cell lumen diameter (CLD) and cell wall thickness (CWT)] in earlywood (EW) and latewood (LW) was determined. To evaluate changes in belowground C status caused by girdling, non-structural carbohydrates (soluble sugars and starch) in coarse roots were determined at the time of girdling and after the growing season. Although fine root mass significantly decreased in response to blockage of phloem C transport, the phenology of root elongation growth was not affected. Surprisingly, radial root growth and CLD of EW tracheids in coarse roots were strikingly increased in drought-stressed trees, when girdling occurred before bud break or during aboveground stem growth. In watered trees, the growth response to girdling was less distinct, but the CWT of EW significantly increased. Starch reserves in the roots of girdled trees significantly decreased in both soil moisture treatments and at all GDs. We conclude that (i) radial growth and wood development in coarse roots of P. abies saplings are not only dependent on current photosynthates, and (ii) blockage of phloem transport induces physiological changes that outweigh drought effects imposed on root cambial activity and cell differentiation. PMID:29636766
Measuring carbon in forests: current status and future challenges.

PubMed

Brown, Sandra

2002-01-01

To accurately and precisely measure the carbon in forests is gaining global attention as countries seek to comply with agreements under the UN Framework Convention on Climate Change. Established methods for measuring carbon in forests exist, and are best based on permanent sample plots laid out in a statistically sound design. Measurements on trees in these plots can be readily converted to aboveground biomass using either biomass expansion factors or allometric regression equations. A compilation of existing root biomass data for upland forests of the world generated a significant regression equation that can be used to predict root biomass based on aboveground biomass only. Methods for measuring coarse dead wood have been tested in many forest types, but the methods could be improved if a non-destructive tool for measuring the density of dead wood was developed. Future measurements of carbon storage in forests may rely more on remote sensing data, and new remote data collection technologies are in development.
Net Primary Productivity and Edaphic Fertility in Two Pluvial Tropical Forests in the Chocó Biogeographical Region of Colombia

PubMed Central

Quinto-Mosquera, Harley

2017-01-01

The net primary productivity (NPP) of tropical forests is a key process of the carbon cycle and therefore for the mitigation of global climate change. It has been proposed that NPP is limited by the availability of soil nutrients in lowland tropical forests and that belowground NPP decreases as edaphic fertility increases. This hypothesis was evaluated in two localities (Opogodó and Pacurita) of the Chocó Biogeographical region, one of the rainiest of the world, where the aboveground (litter and wood) and belowground (fine and coarse roots) components of NPP were measured. Fertility parameters (pH, nutrients, and texture) were also determined and related to NPP. Total NPP was similar between locations (23.7 vs. 24.2 t ha-1 year-1 for Opogodó and Pacurita, respectively). However, components of NPP showed differences: in Pacurita, with steeper topography, NPP of wood and coarse roots were higher; therefore, differences of topography and drainage between localities probably affected the NPP of wood. On the other hand, soils of Opogodó, where NPP of fine roots was higher, showed higher contents of sand, N+, and organic matter (OM). With the increase of pH, OM, N+, K, Mg, and sand, the NPP of leaves and fine roots as well as the percentage of NPP belowground also increased, which suggests NPP limitation by multiple nutrients. The increase of NPP belowground with the availability of edaphic nutrients evidenced a redistribution of the aboveground and belowground components of NPP with the increase of soil fertility in oligotrophic systems, probably as a mechanism to improve the capture of resources. PMID:28114418
Net Primary Productivity and Edaphic Fertility in Two Pluvial Tropical Forests in the Chocó Biogeographical Region of Colombia.

PubMed

Quinto-Mosquera, Harley; Moreno, Flavio

2017-01-01

The net primary productivity (NPP) of tropical forests is a key process of the carbon cycle and therefore for the mitigation of global climate change. It has been proposed that NPP is limited by the availability of soil nutrients in lowland tropical forests and that belowground NPP decreases as edaphic fertility increases. This hypothesis was evaluated in two localities (Opogodó and Pacurita) of the Chocó Biogeographical region, one of the rainiest of the world, where the aboveground (litter and wood) and belowground (fine and coarse roots) components of NPP were measured. Fertility parameters (pH, nutrients, and texture) were also determined and related to NPP. Total NPP was similar between locations (23.7 vs. 24.2 t ha-1 year-1 for Opogodó and Pacurita, respectively). However, components of NPP showed differences: in Pacurita, with steeper topography, NPP of wood and coarse roots were higher; therefore, differences of topography and drainage between localities probably affected the NPP of wood. On the other hand, soils of Opogodó, where NPP of fine roots was higher, showed higher contents of sand, N+, and organic matter (OM). With the increase of pH, OM, N+, K, Mg, and sand, the NPP of leaves and fine roots as well as the percentage of NPP belowground also increased, which suggests NPP limitation by multiple nutrients. The increase of NPP belowground with the availability of edaphic nutrients evidenced a redistribution of the aboveground and belowground components of NPP with the increase of soil fertility in oligotrophic systems, probably as a mechanism to improve the capture of resources.
Tropical secondary forests regenerating after shifting cultivation in the Philippines uplands are important carbon sinks.

PubMed

Mukul, Sharif A; Herbohn, John; Firn, Jennifer

2016-03-08

In the tropics, shifting cultivation has long been attributed to large scale forest degradation, and remains a major source of uncertainty in forest carbon accounting. In the Philippines, shifting cultivation, locally known as kaingin, is a major land-use in upland areas. We measured the distribution and recovery of aboveground biomass carbon along a fallow gradient in post-kaingin secondary forests in an upland area in the Philippines. We found significantly higher carbon in the aboveground total biomass and living woody biomass in old-growth forest, while coarse dead wood biomass carbon was higher in the new fallow sites. For young through to the oldest fallow secondary forests, there was a progressive recovery of biomass carbon evident. Multivariate analysis indicates patch size as an influential factor in explaining the variation in biomass carbon recovery in secondary forests after shifting cultivation. Our study indicates secondary forests after shifting cultivation are substantial carbon sinks and that this capacity to store carbon increases with abandonment age. Large trees contribute most to aboveground biomass. A better understanding of the relative contribution of different biomass sources in aboveground total forest biomass, however, is necessary to fully capture the value of such landscapes from forest management, restoration and conservation perspectives.
Tropical secondary forests regenerating after shifting cultivation in the Philippines uplands are important carbon sinks

PubMed Central

Mukul, Sharif A.; Herbohn, John; Firn, Jennifer

2016-01-01

In the tropics, shifting cultivation has long been attributed to large scale forest degradation, and remains a major source of uncertainty in forest carbon accounting. In the Philippines, shifting cultivation, locally known as kaingin, is a major land-use in upland areas. We measured the distribution and recovery of aboveground biomass carbon along a fallow gradient in post-kaingin secondary forests in an upland area in the Philippines. We found significantly higher carbon in the aboveground total biomass and living woody biomass in old-growth forest, while coarse dead wood biomass carbon was higher in the new fallow sites. For young through to the oldest fallow secondary forests, there was a progressive recovery of biomass carbon evident. Multivariate analysis indicates patch size as an influential factor in explaining the variation in biomass carbon recovery in secondary forests after shifting cultivation. Our study indicates secondary forests after shifting cultivation are substantial carbon sinks and that this capacity to store carbon increases with abandonment age. Large trees contribute most to aboveground biomass. A better understanding of the relative contribution of different biomass sources in aboveground total forest biomass, however, is necessary to fully capture the value of such landscapes from forest management, restoration and conservation perspectives. PMID:26951761
Tropical secondary forests regenerating after shifting cultivation in the Philippines uplands are important carbon sinks

NASA Astrophysics Data System (ADS)

Mukul, Sharif A.; Herbohn, John; Firn, Jennifer

2016-03-01

In the tropics, shifting cultivation has long been attributed to large scale forest degradation, and remains a major source of uncertainty in forest carbon accounting. In the Philippines, shifting cultivation, locally known as kaingin, is a major land-use in upland areas. We measured the distribution and recovery of aboveground biomass carbon along a fallow gradient in post-kaingin secondary forests in an upland area in the Philippines. We found significantly higher carbon in the aboveground total biomass and living woody biomass in old-growth forest, while coarse dead wood biomass carbon was higher in the new fallow sites. For young through to the oldest fallow secondary forests, there was a progressive recovery of biomass carbon evident. Multivariate analysis indicates patch size as an influential factor in explaining the variation in biomass carbon recovery in secondary forests after shifting cultivation. Our study indicates secondary forests after shifting cultivation are substantial carbon sinks and that this capacity to store carbon increases with abandonment age. Large trees contribute most to aboveground biomass. A better understanding of the relative contribution of different biomass sources in aboveground total forest biomass, however, is necessary to fully capture the value of such landscapes from forest management, restoration and conservation perspectives.
Characterizing and contrasting instream and riparian coarse wood in western Montana basins

Treesearch

Michael K. Young; Ethan A. Mace; Eric T. Ziegler; Elaine K. Sutherland

2006-01-01

The importance of coarse wood to aquatic biota and stream channel structure is widely recognized, yet characterizations of large-scale patterns in coarse wood dimensions and loads are rare. To address these issues, we censused instream coarse wood ( 2 m long and 10 cm minimum diameter) and sampled riparian coarse wood and channel characteristics in and along 13 streams...
Dead wood biomass and turnover time, measured by radiocarbon, along a subalpine elevation gradient.

PubMed

Kueppers, Lara M; Southon, John; Baer, Paul; Harte, John

2004-12-01

Dead wood biomass can be a substantial fraction of stored carbon in forest ecosystems, and coarse woody debris (CWD) decay rates may be sensitive to climate warming. We used an elevation gradient in Colorado Rocky Mountain subalpine forest to examine climate and species effects on dead wood biomass, and on CWD decay rate. Using a new radiocarbon approach, we determined that the turnover time of lodgepole pine CWD (340+/-130 years) was roughly half as long in a site with 2.5-3 degrees C warmer air temperature, as that of pine (630+/-400 years) or Engelmann spruce CWD (800+/-960 and 650+/-410 years) in cooler sites. Across all sites and both species, CWD age ranged from 2 to 600 years, and turnover time was 580+/-180 years. Total standing and fallen dead wood biomass ranged from 4.7+/-0.2 to 54+/-1 Mg ha(-1), and from 2.8 to 60% of aboveground live tree biomass. Dead wood biomass increased 75 kg ha(-1) per meter gain in elevation and decreased 13 Mg ha(-1) for every degree C increase in mean air temperature. Differences in biomass and decay rates along the elevation gradient suggest that climate warming will lead to a loss of dead wood carbon from subalpine forest.
Community-weighted mean of leaf traits and divergence of wood traits predict aboveground biomass in secondary subtropical forests.

PubMed

Ali, Arshad; Yan, En-Rong; Chang, Scott X; Cheng, Jun-Yang; Liu, Xiang-Yu

2017-01-01

Subtropical forests are globally important in providing ecological goods and services, but it is not clear whether functional diversity and composition can predict aboveground biomass in such forests. We hypothesized that high aboveground biomass is associated with high functional divergence (FDvar, i.e., niche complementarity) and community-weighted mean (CWM, i.e., mass ratio; communities dominated by a single plant strategy) of trait values. Structural equation modeling was employed to determine the direct and indirect effects of stand age and the residual effects of CWM and FDvar on aboveground biomass across 31 plots in secondary forests in subtropical China. The CWM model accounted for 78, 20, 6 and 2% of the variation in aboveground biomass, nitrogen concentration in young leaf, plant height and specific leaf area of young leaf, respectively. The FDvar model explained 74, 13, 7 and 0% of the variation in aboveground biomass, plant height, twig wood density and nitrogen concentration in young leaf, respectively. The variation in aboveground biomass, CWM of leaf nitrogen concentration and specific leaf area, and FDvar of plant height, twig wood density and nitrogen concentration in young leaf explained by the joint model was 86, 20, 13, 7, 2 and 0%, respectively. Stand age had a strong positive direct effect but low indirect positive effects on aboveground biomass. Aboveground biomass was negatively related to CWM of nitrogen concentration in young leaf, but positively related to CWM of specific leaf area of young leaf and plant height, and FDvar of plant height, twig wood density and nitrogen concentration in young leaf. Leaf and wood economics spectra are decoupled in regulating the functionality of forests, communities with diverse species but high nitrogen conservative and light acquisitive strategies result in high aboveground biomass, and hence, supporting both the mass ratio and niche complementarity hypotheses in secondary subtropical forests. Copyright © 2016 Elsevier B.V. All rights reserved.
Aboveground tree biomass statistics for Maine: 1982

Treesearch

Eric H. Wharton; Thomas S. Frieswyk; Anne M. Malley

1985-01-01

Traditional measures of volume inadequately describe the total aboveground wood resource. The 1980-82 inventory of Maine included estimates of aboveground tree biomass on timberland. There are nearly 1,504.4 million green tons of wood and bark in all trees above the ground level, or 88.2 green tons per acre of timberland. Most of the biomass is in growing stock, but 49...
Basin-wide variations in Amazon forest structure and function are mediated by both soils and climate

NASA Astrophysics Data System (ADS)

Quesada, C. A.; Phillips, O. L.; Schwarz, M.; Czimczik, C. I.; Baker, T. R.; Patiño, S.; Fyllas, N. M.; Hodnett, M. G.; Herrera, R.; Almeida, S.; Alvarez Dávila, E.; Arneth, A.; Arroyo, L.; Chao, K. J.; Dezzeo, N.; Erwin, T.; di Fiore, A.; Higuchi, N.; Honorio Coronado, E.; Jimenez, E. M.; Killeen, T.; Lezama, A. T.; Lloyd, G.; López-González, G.; Luizão, F. J.; Malhi, Y.; Monteagudo, A.; Neill, D. A.; Núñez Vargas, P.; Paiva, R.; Peacock, J.; Peñuela, M. C.; Peña Cruz, A.; Pitman, N.; Priante Filho, N.; Prieto, A.; Ramírez, H.; Rudas, A.; Salomão, R.; Santos, A. J. B.; Schmerler, J.; Silva, N.; Silveira, M.; Vásquez, R.; Vieira, I.; Terborgh, J.; Lloyd, J.

2012-06-01

Forest structure and dynamics vary across the Amazon Basin in an east-west gradient coincident with variations in soil fertility and geology. This has resulted in the hypothesis that soil fertility may play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates. Soil samples were collected in a total of 59 different forest plots across the Amazon Basin and analysed for exchangeable cations, carbon, nitrogen and pH, with several phosphorus fractions of likely different plant availability also quantified. Physical properties were additionally examined and an index of soil physical quality developed. Bivariate relationships of soil and climatic properties with above-ground wood productivity, stand-level tree turnover rates, above-ground wood biomass and wood density were first examined with multivariate regression models then applied. Both forms of analysis were undertaken with and without considerations regarding the underlying spatial structure of the dataset. Despite the presence of autocorrelated spatial structures complicating many analyses, forest structure and dynamics were found to be strongly and quantitatively related to edaphic as well as climatic conditions. Basin-wide differences in stand-level turnover rates are mostly influenced by soil physical properties with variations in rates of coarse wood production mostly related to soil phosphorus status. Total soil P was a better predictor of wood production rates than any of the fractionated organic- or inorganic-P pools. This suggests that it is not only the immediately available P forms, but probably the entire soil phosphorus pool that is interacting with forest growth on longer timescales. A role for soil potassium in modulating Amazon forest dynamics through its effects on stand-level wood density was also detected. Taking this into account, otherwise enigmatic variations in stand-level biomass across the Basin were then accounted for through the interacting effects of soil physical and chemical properties with climate. A hypothesis of self-maintaining forest dynamic feedback mechanisms initiated by edaphic conditions is proposed. It is further suggested that this is a major factor determining endogenous disturbance levels, species composition, and forest productivity across the Amazon Basin.
Disentangling the drivers of coarse woody debris behavior and carbon gas emissions during fire

NASA Astrophysics Data System (ADS)

Zhao, Weiwei; van der Werf, Guido R.; van Logtestijn, Richard S. P.; van Hal, Jurgen R.; Cornelissen, Johannes H. C.

2016-04-01

The turnover of coarse woody debris, a key terrestrial carbon pool, plays fundamental roles in global carbon cycling. Biological decomposition and fire are two main fates for dead wood turnover. Compared to slow decomposition, fire rapidly transfers organic carbon from the earth surface to the atmosphere. Both a-biotic environmental factors and biotic wood properties determine coarse wood combustion and thereby its carbon gas emissions during fire. Moisture is a key inhibitory environmental factor for fire. The properties of dead wood strongly affect how it burns either directly or indirectly through interacting with moisture. Coarse wood properties vary between plant species and between various decay stages. Moreover, if we put a piece of dead wood in the context of a forest fuel bed, the soil and wood contact might also greatly affect their fire behavior. Using controlled laboratory burns, we disentangled the effects of all these driving factors: tree species (one gymnosperms needle-leaf species, three angiosperms broad-leaf species), wood decay stages (freshly dead, middle decayed, very strongly decayed), moisture content (air-dried, 30% moisture content in mass), and soil-wood contact (on versus 3cm above the ground surface) on dead wood flammability and carbon gas efflux (CO2 and CO released in grams) during fire. Wood density was measured for all coarse wood samples used in our experiment. We found that compared to other drivers, wood decay stages have predominant positive effects on coarse wood combustion (for wood mass burned, R2=0.72 when air-dried and R2=0.52 at 30% moisture content) and associated carbon gas emissions (for CO2andCO (g) released, R2=0.55 when air-dried and R2=0.42 at 30% moisture content) during fire. Thus, wood decay accelerates wood combustion and its CO2 and CO emissions during fire, which can be mainly attributed to the decreasing wood density (for wood mass burned, R2=0.91 when air-dried and R2=0.63 at 30% moisture content) as wood becomes more decomposed. Our results provide quantitative experimental evidence for how several key abiotic and biotic factors, especially moisture content and the key underlying trait wood density, as well as their interactions, together drive coarse wood carbon turnover through fire. Our experimental data on coarse wood behavior and gas efflux during fire will help to improve the predictive power of global vegetation climate models on dead wood turnover and its feedback to climate.
Shading aboveground L-joint and lap-joint tests : comparison of white pine and sugar maple test assemblies

Treesearch

Carol A. Clausen; Daniel L. Lindner

2011-01-01

Five-year performance ratings are presented for two types of untreated, uncoated wood joints (L and lap) in aboveground tests under shaded conditions. The effect of shading on moisture entrapment in pine and maple L and lap joints was evaluated in a moderate decay zone (Madison, Wisconsin). Variations were observed between wood species, visual ratings, joint type,...
Evaluating Naturally Durable Wood Species for Repair and Rehabilitation of Above-Ground Components of Covered Bridges

Treesearch

Grant T. Kirker; Carol A. Clausen; A. B Blodgett; Stan T. Lebow

2013-01-01

More than 1,500 covered bridges remain in the United States. They are a unique part of our history; thus, replacement of bridge components is an equally important part of preserving this uncommon style of craftsmanship. The goal of this project was to evaluate seven wood species for their durability in above-ground field exposure. Chemical analysis was also conducted...
Quantifying the coarse-root biomass of intensively managed loblolly pine plantations

Treesearch

Ashley T. Miller; H. Lee Allen; Chris A. Maier

2006-01-01

Most of the carbon accumulation during a forest rotation is in plant biomass and the forest floor. Most of the belowground biomass in older loblolly pine (Pinus taeda L.) forests is in coarse roots, and coarse roots persist longer after harvest than aboveground biomass and fine roots. The main objective was to assess the carbon accumulation in coarse...
Quantifying the coarse-root biomass of intensively managed loblolly pine plantations

Treesearch

Ashley T. Miller; H. Lee Allen; Chris A. Maier

2006-01-01

Most of the carbon accumulation during a forest rotation is in plant biomass and the forest floor. Most of the belowground biomass in older loblolly pine (Pinus taeda L.) forests is in coarse roots, and coarse roots ersist longer after harvest than aboveground biomass and fine oots. The main objective was to assess the carbon accumulation in coarse...
Where Does Wood Most Effectively Enhance Storage? Network-Scale Distribution of Sediment and Organic Matter Stored by Instream Wood

NASA Astrophysics Data System (ADS)

Pfeiffer, Andrew; Wohl, Ellen

2018-01-01

We used 48 reach-scale measurements of large wood and wood-associated sediment and coarse particulate organic matter (CPOM) storage within an 80 km2 catchment to examine spatial patterns of storage relative to stream order. Wood, sediment, and CPOM are not distributed uniformly across the drainage basin. Third- and fourth-order streams (23% of total stream length) disproportionately store wood and coarse and fine sediments: 55% of total wood volume, 78% of coarse sediment, and 49% of fine sediment, respectively. Fourth-order streams store 0.8 m3 of coarse sediment and 0.2 m3 of fine sediment per cubic meter of wood. CPOM storage is highest in first-order streams (60% of storage in 47% of total network stream length). First-order streams can store up to 0.3 m3 of CPOM for each cubic meter of wood. Logjams in third- and fourth-order reaches are primary sediment storage agents, whereas roots in small streams may be more important for storage of CPOM. We propose the large wood particulate storage index to quantify average volume of sediment or CPOM stored by a cubic meter of wood.
Aboveground biomass, wood volume, nutrient stocks and leaf litter in novel forests compared to native forests and tree plantations in Puerto Rico

Treesearch

A.E. Lugo; O. Abelleira Martínez; J. Fonseca da Silva

2012-01-01

The article presents comparative data for aboveground biomass, wood volume, nutirent stocks (N, P, K) and leaf litter in different types of forests in Puerto Rico. The aim of the study is to assess how novel forests of Castilla elastica, Panama Rubber Tree, and Spathodea campanulata, African Tulip Tree, compare with tree plantations and native historical forests (both...

Long-term simulations of forest management impacts on carbon storage from loblolly pine plantations in the Southern U.S.

Treesearch

Huei-Jin Wang; Philip J. Radtke; Stephen P. Prisley

2012-01-01

Accounting for forest components in carbon accounting systems may be insufficient when substantial amounts of sequestered carbon are harvested and converted to wood products in use and in landfill. The potential of forest offset â in-woods aboveground carbon storage, carbon stored in harvested wood, and energy offset by burning harvested wood â from loblolly pine...
Ecology of coarse wood decomposition by the saprotrophic fungus Fomes fomentarius.

PubMed

Větrovský, Tomáš; Voříšková, Jana; Snajdr, Jaroslav; Gabriel, Jiří; Baldrian, Petr

2011-07-01

Saprotrophic wood-inhabiting basidiomycetes are the most important decomposers of lignin and cellulose in dead wood and as such they attracted considerable attention. The aims of this work were to quantify the activity and spatial distribution of extracellular enzymes in coarse wood colonised by the white-rot basidiomycete Fomes fomentarius and in adjacent fruitbodies of the fungus and to analyse the diversity of the fungal and bacterial community in a fungus-colonised wood and its potential effect on enzyme production by F. fomentarius. Fungus-colonised wood and fruitbodies were collected in low management intensity forests in the Czech Republic. There were significant differences in enzyme production by F. fomentarius between Betula pendula and Fagus sylvatica wood, the activity of cellulose and xylan-degrading enzymes was significantly higher in beech wood than in birch wood. Spatial analysis of a sample B. pendula log segment proved that F. fomentarius was the single fungal representative found in the log. There was a high level of spatial variability in the amount of fungal biomass detected, but no effects on enzyme activities were observed. Samples from the fruiting body showed high β-glucosidase and chitinase activities compared to wood samples. Significantly higher levels of xylanase and cellobiohydrolase were found in samples located near the fruitbody (proximal), and higher laccase and Mn-peroxidase activities were found in the distal ones. The microbial community in wood was dominated by the fungus (fungal to bacterial DNA ratio of 62-111). Bacterial abundance composition was lower in proximal than distal parts of wood by a factor of 24. These results show a significant level of spatial heterogeneity in coarse wood. One of the explanations may be the successive colonization of wood by the fungus: due to differential enzyme production, the rates of biodegradation of coarse wood are also spatially inhomogeneous.
Controls on coarse wood decay in temperate tree species: birth of the LOGLIFE experiment.

PubMed

Cornelissen, Johannes H C; Sass-Klaassen, Ute; Poorter, Lourens; van Geffen, Koert; van Logtestijn, Richard S P; van Hal, Jurgen; Goudzwaard, Leo; Sterck, Frank J; Klaassen, René K W M; Freschet, Grégoire T; van der Wal, Annemieke; Eshuis, Henk; Zuo, Juan; de Boer, Wietse; Lamers, Teun; Weemstra, Monique; Cretin, Vincent; Martin, Rozan; Ouden, Jan den; Berg, Matty P; Aerts, Rien; Mohren, Godefridus M J; Hefting, Mariet M

2012-01-01

Dead wood provides a huge terrestrial carbon stock and a habitat to wide-ranging organisms during its decay. Our brief review highlights that, in order to understand environmental change impacts on these functions, we need to quantify the contributions of different interacting biotic and abiotic drivers to wood decomposition. LOGLIFE is a new long-term 'common-garden' experiment to disentangle the effects of species' wood traits and site-related environmental drivers on wood decomposition dynamics and its associated diversity of microbial and invertebrate communities. This experiment is firmly rooted in pioneering experiments under the directorship of Terry Callaghan at Abisko Research Station, Sweden. LOGLIFE features two contrasting forest sites in the Netherlands, each hosting a similar set of coarse logs and branches of 10 tree species. LOGLIFE welcomes other researchers to test further questions concerning coarse wood decay that will also help to optimise forest management in view of carbon sequestration and biodiversity conservation.
Performance of Northeastern United States wood species treated with copper based preservatives: 10 year above-ground decking evaluation

Treesearch

S. T. Lebow; S. A. Halverson

2015-01-01

Research was conducted to evaluate the decking performance of northeastern United States wood species treated with copper based preservatives. Decking specimens were treated with one of four wood preservatives and exposed near Madison, Wisconsin. Specimens were evaluated for biological attack and dimensional stability. After 10 years, none of the preservative treated...
Changes in carbon allocation to aboveground versus belowground forest components is driven by a trade-off involving mycorrhizal fungi, not fine roots

NASA Astrophysics Data System (ADS)

Ouimette, A.; Ollinger, S. V.; Hobbie, E. A.; Lepine, L. C.; Stephens, R.; Rowe, R.; Vadeboncoeur, M. A.; Tumber-Davila, S. J.

2017-12-01

Species composition and resource availability exert a strong influence on the dynamics of carbon allocation among different forest ecosystem components. Recent work in temperate forests has highlighted a tradeoff between carbon allocation to aboveground woody tissues (access to light), and belowground to fine roots (access to soil nutrients). Although root-associated mycorrhizal fungi are crucial for N acquisition and can receive 20% or more of annual net primary production, most studies fail to explicitly include carbon allocation to mycorrhizal fungi. In part, this is due to the inherent difficulties in accurately quantifying fungal production. We took several approaches to quantify production of mycorrhizal fungi, including a carbon budget approach and isotopic techniques. Here we present data on patterns of carbon allocation to aboveground (wood and foliar production), and belowground components (production of fine roots and mycorrhizal fungi), across temperate forest stands spanning a range of nitrogen availability and species composition. We found that as the proportion of conifer species decreased, and stand nitrogen availability increased, both the absolute amount and the fraction of net primary production increased for foliage, aboveground wood, and fine roots ("a rising tide lifts all boats"). While allocation to plant pools increased, allocation to mycorrhizal fungi significantly decreased with decreasing conifer dominance and increasing soil nitrogen availability. We did not find a strong trade-off between carbon allocation to fine roots and aboveground wood or foliage. Instead, a negative relationship is seen between allocation to mycorrhizal fungi and other plant pools. Effort to estimate carbon allocation to mycorrhizal fungi is important for gaining a more complete understanding of how ecosystems respond to changes in growth-limiting resources.
Productivity of aboveground coarse wood biomass and stand age related to soil hydrology of Amazonian forests in the Purus-Madeira interfluvial area

NASA Astrophysics Data System (ADS)

Cintra, B. B. L.; Schietti, J.; Emillio, T.; Martins, D.; Moulatlet, G.; Souza, P.; Levis, C.; Quesada, C. A.; Schöngart, J.

2013-04-01

The ongoing demand for information on forest productivity has increased the number of permanent monitoring plots across the Amazon. Those plots, however, do not comprise the whole diversity of forest types in the Amazon. The complex effects of soil, climate and hydrology on the productivity of seasonally waterlogged interfluvial wetland forests are still poorly understood. The presented study is the first field-based estimate for tree ages and wood biomass productivity in the vast interfluvial region between the Purus and Madeira rivers. We estimate stand age and wood biomass productivity by a combination of tree-ring data and allometric equations for biomass stocks of eight plots distributed along 600 km in the Purus-Madeira interfluvial area that is crossed by the BR-319 highway. We relate stand age and wood biomass productivity to hydrological and edaphic conditions. Mean productivity and stand age were 5.6 ± 1.1 Mg ha-1 yr-1 and 102 ± 18 yr, respectively. There is a strong relationship between tree age and diameter, as well as between mean diameter increment and mean wood density within a plot. Regarding the soil hydromorphic properties we find a positive correlation with wood biomass productivity and a negative relationship with stand age. Productivity also shows a positive correlation with the superficial phosphorus concentration. In addition, superficial phosphorus concentration increases with enhanced soil hydromorphic condition. We raise three hypotheses to explain these results: (1) the reduction of iron molecules on the saturated soils with plinthite layers close to the surface releases available phosphorous for the plants; (2) the poor structure of the saturated soils creates an environmental filter selecting tree species of faster growth rates and shorter life spans and (3) plant growth on saturated soil is favored during the dry season, since there should be low restrictions for soil water availability.
Decomposition of coarse woody debris originating by clearcutting of an old-growth conifer forest

Treesearch

Jack E. Janisch; Mark E. Harmon; Hua Chen; Becky Fasth; Jay Sexton

2005-01-01

Decomposition constants (k) for aboveground logs and stumps and subsurface coarse roots originating from harvested old-growth forest (estimated age 400 to 600 y) were assessed by volume-density change methods along a 70-y chronosequence of clearcuts on the Wind River Ranger District, Washington, USA. Principal species sampled were Tsuga heterophylla...
Biomass statistics for Vermont - 1983

Treesearch

Thomas S. Frieswyk; Anne M. Malley

1986-01-01

A new measure of the forest resource has been added to the fourth forest inventory of Vermont. The inventory, which was conducted in 1982-83, included estimates of aboveground tree biomass on timberland. There are approximately 413 million green tons of wood and bark in the aboveground portion of all trees, which equates to an average of 93 green tons per acre...
Effect of thinning on partitioning of aboveground biomass in naturally regenerated shortleaf pine (Pinus echinata mill.)

Treesearch

Charles O. Sabatia; Rodney E. Will; Thomas B. Lynch

2010-01-01

In traditional harvesting systems, yield of forest stands may increase if a greater proportion of net primary production is allocated to bole wood. However, for management related to whole-tree harvesting, carbon sequestration, biofuels, and wildland fire avoidance, assessments of biomass partitioning to all aboveground components is needed. Thinning increases bole...
A coarse wood dynamics model for the Western Cascades.

Treesearch

K. Mellen; A. Ager

2002-01-01

The Coarse Wood Dynamics Model (CWDM) analyzes the dynamics (fall, fragmentation, and decomposition) of Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) snags and down logs in forested ecosystems of the western Cascades of Oregon and Washington. The model predicts snag fall, height loss and decay,...
Prescribed fire effects on field-derived and simulated forest carbon stocks over time

Treesearch

Nicole M. Vaillant; Alicia L. Reiner; Erin K. Noonan-Wright

2013-01-01

To better understand the impact of prescribed fire on carbon stocks, we quantified aboveground and belowground carbon stocks within five pools (live trees and coarse roots, dead trees and coarse roots, live understory vegetation, down woody debris, and litter and duff) and potential carbon emissions from a simulated wildfire before and up to 8 years after prescribed...
Biomass statistics for New Hampshire - 1983

Treesearch

Thomas S. Frieswyk; Anne M. Malley

1986-01-01

A new measure of the forest resource has been added to the fourth forest inventory of New Hampshire. The inventory, which was conducted in 1982-83, included estimates of aboveground tree biomass on timberland. There are approximately 502 million green tons of wood and bark in the aboveground portion of all trees, or 104 green tons per acre. Fifty-five percent or 275...
Identifying aboveground wood fiber potentials in New York State

Treesearch

Eric H. Wharton

1984-01-01

New York forests are made up of more than just the growing stock that is measured during conventional forest inventories. A biomass inventory, completed in 1980, showed that New York commercial forest lands contain nearly 1,164.4 million green tons of aboveground tree biomass, or an average of 75.6 green tons per acre. Conventional growing stock accounted for 57...
Combining LIDAR estimates of aboveground biomass and Landsat estimates of stand age for spatially extensive validation of modeled forest productivity.

Treesearch

M.A. Lefsky; D.P. Turner; M. Guzy; W.B. Cohen

2005-01-01

Extensive estimates of forest productivity are required to understand the relationships between shifting land use, changing climate and carbon storage and fluxes. Aboveground net primary production of wood (NPPAw) is a major component of total NPP and of net ecosystem production (NEP). Remote sensing of NPP and NPPAw is...
Methane and carbon dioxide flux in the profile of wood ant (Formica aquilonia) nests and the surrounding forest floor during a laboratory incubation.

PubMed

Jílková, Veronika; Picek, Tomáš; Šestauberová, Martina; Krištůfek, Václav; Cajthaml, Tomáš; Frouz, Jan

2016-10-01

We compared methane (CH4) and carbon dioxide (CO2) fluxes in samples collected from the aboveground parts of wood ant nests and in the organic and mineral layer of the surrounding forest floor. Gas fluxes were measured during a laboratory incubation, and microbial properties (abundance of fungi, bacteria and methanotrophic bacteria) and nutrient contents (total and available carbon and nitrogen) were also determined. Both CO2 and CH4 were produced from ant nest samples, indicating that the aboveground parts of wood ant nests act as sources of both gases; in comparison, the forest floor produced about four times less CO2 and consumed rather than produced CH4 Fluxes of CH4 and CO2 were positively correlated with contents of available carbon and nitrogen. The methanotrophic community was represented by type II methanotrophic bacteria, but their abundance did not explain CH4 flux. Fungal abundance was greater in ant nest samples than in forest floor samples, but bacterial abundance was similar in both kinds of samples, suggesting that the organic materials in the nests may have been too recalcitrant for bacteria to decompose. The results indicate that the aboveground parts of wood ant nests are hot spots of CO2 and CH4 production in the forest floor. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Coarse woody debris carbon storage across a mean annual temperature gradient in tropical montane wet forest

Treesearch

Darcey K. Iwashita; Creighton M. Litton; Christian P. Giardina

2013-01-01

Coarse woody debris (CWD; defined here as fallen and standing dead trees and tree ferns) is a critical structural and functional component of forest ecosystems that typically comprises a large proportion of total aboveground carbon (C) storage. However, CWD estimates for the tropics are uncommon, and little is known about how C storage in CWD will respond to climate...
Early detection and progression of decay in L-joints and lap-joints in a moderate decay hazard zone

Treesearch

Carol A. Clausen; Terry L. Highley; Daniel L. Lindner

2006-01-01

Accelerated test methods are needed to evaluate the initiation and progression of decay in wood exposed aboveground. The relationship between test conditions and initiation of decay, however, is poorly understood. Southern pine and maple L-joints and lap-joints were exposed aboveground in a configuration that encouraged water entrapment at the Valley View Experimental...
Aboveground tree biomass on productive forest land in Alaska.

Treesearch

John Yarie; Delbert Mead

1982-01-01

Total aboveground woody biomass of trees on forest land that can produce 1.4 cubic m eters per hectare per year of industrial wood in Alaska is 1.33 billion metric tons green weight. The estimated energy value of the standing woody biomass is 11.9 x 10'5 Btu's. Statewide tables of biomass and energy values for softwoods, hardwoods, and species groups are...
Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests

Treesearch

Fabien H. Wagner; Bruno Herault; Damien Bonal; Clement Stahl; Liana O. Anderson; Timothy R. Baker; Gabriel Sebastian Becker; Hans Beeckman; Danilo Boanerges Souza; Paulo Cesar Botosso; David M. J. S. Bowman; Achim Brauning; Benjamin Brede; Foster Irving Brown; Jesus Julio Camarero; Plinio Barbosa Camargo; Fernanda C. G. Cardoso; Fabricio Alvim Carvalho; Wendeson Castro; Rubens Koloski Chagas; Jerome Chave; Emmanuel N. Chidumayo; Deborah A. Clark; Flavia Regina Capellotto Costa; Camille Couralet; Paulo Henrique da Silva Mauricio; Helmut Dalitz; Vinicius Resende de Castro; Jacanan Eloisa de Freitas Milani; Edilson Consuelo de Oliveira; Luciano de Souza Arruda; Jean-Louis Devineau; David M. Drew; Oliver Dunisch; Giselda Durigan; Elisha Elifuraha; Marcio Fedele; Ligia Ferreira Fedele; Afonso Figueiredo Filho; Cesar Augusto Guimaraes Finger; Augusto Cesar Franco; Joao Lima Freitas Junior; Franklin Galvao; Aster Gebrekirstos; Robert Gliniars; Paulo Mauricio Lima de Alencastro Graca; Anthony D. Griffiths; James Grogan; Kaiyu Guan; Jurgen Homeier; Maria Raquel Kanieski; Lip Khoon Kho; Jennifer Koenig; Sintia Valerio Kohler; Julia Krepkowski; Jose Pires Lemos-Filho; Diana Lieberman; Milton Eugene Lieberman; Claudio Sergio Lisi; Tomaz Longhi Santos; Jose Luis Lopez Ayala; Eduardo Eijji Maeda; Yadvinder Malhi; Vivian R. B. Maria; Marcia C. M. Marques; Renato Marques; Hector Maza Chamba; Lawrence Mbwambo; Karina Liana Lisboa Melgaco; Hooz Angela Mendivelso; Brett P. Murphy; Joseph O' Brien; Steven F. Oberbauer; Naoki Okada; Raphael Pelissier; Lynda D. Prior; Fidel Alejandro Roig; Michael Ross; Davi Rodrigo Rossatto; Vivien Rossi; Lucy Rowland; Ervan Rutishauser; Hellen Santana; Mark Schulze; Diogo Selhorst; Williamar Rodrigues Silva; Marcos Silveira; Susanne Spannl; Michael D. Swaine; Jose Julio Toledo; Marcos Miranda Toledo; Marisol Toledo; Takeshi Toma; Mario Tomazello Filho; Juan Ignacio Valdez Hernandez; Jan Verbesselt; Simone Aparecida Vieira; Gregoire Vincent; Carolina Volkmer de Castilho; Franziska Volland; Martin Worbes; Magda Lea Bolzan Zanon; Luiz E. O. C. Aragao

2016-01-01

The seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combination of seasonal pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measurements and 35 litter...
Enhancing composite durability : using thermal treatments

Treesearch

Jerrold E. Winandy; W. Ramsay Smith

2007-01-01

The use of thermal treatments to enhance the moisture resistance and aboveground durability of solid wood materials has been studied for years. Much work was done at the Forest Products Laboratory in the last 15 years on the fundamental process of both short-and long-term exposure to heat on wood materials and its interaction with various treatment chemicals. This work...

Study of Wetland Ecosystem Vegetation Using Satellite Data

NASA Astrophysics Data System (ADS)

Dyukarev, E. A.; Alekseeva, M. N.; Golovatskaya, E. A.

2017-12-01

The normalized difference vegetation index (NDVI) is used to estimate the aboveground net production (ANP) of wetland ecosystems for the key area at the South Taiga zone of West Siberia. The vegetation index and aboveground production are related by linear dependence and are specific for each wetland ecosystem. The NDVI grows with an increase in the ANP at wooded oligotrophic ecosystems. Open oligotrophic bogs and eutrophic wetlands are characterized by an opposite relation. Maps of aboveground production for wetland ecosystems are constructed for each study year and for the whole period of studies. The average aboveground production for all wetland ecosystems of the key area, which was estimated with consideration for the area they occupy and using the data of satellite measurements of the vegetation index, is 305 g C/m2/yr. The total annual carbon accumulation in aboveground wetland vegetation in the key area is 794600 t.
Trade-offs between xylem hydraulic properties, wood anatomy and yield in Populus.

PubMed

Hajek, Peter; Leuschner, Christoph; Hertel, Dietrich; Delzon, Sylvain; Schuldt, Bernhard

2014-07-01

Trees face the dilemma that achieving high plant productivity is accompanied by a risk of drought-induced hydraulic failure due to a trade-off in the trees' vascular system between hydraulic efficiency and safety. By investigating the xylem anatomy of branches and coarse roots, and measuring branch axial hydraulic conductivity and vulnerability to cavitation in 4-year-old field-grown aspen plants of five demes (Populus tremula L. and Populus tremuloides Michx.) differing in growth rate, we tested the hypotheses that (i) demes differ in wood anatomical and hydraulic properties, (ii) hydraulic efficiency and safety are related to xylem anatomical traits, and (iii) aboveground productivity and hydraulic efficiency are negatively correlated to cavitation resistance. Significant deme differences existed in seven of the nine investigated branch-related anatomical and hydraulic traits but only in one of the four coarse-root-related anatomical traits; this likely is a consequence of high intra-plant variation in root morphology and the occurrence of a few 'high-conductivity roots'. Growth rate was positively related to branch hydraulic efficiency (xylem-specific conductivity) but not to cavitation resistance; this indicates that no marked trade-off exists between cavitation resistance and growth. Both branch hydraulic safety and hydraulic efficiency significantly depended on vessel size and were related to the genetic distance between the demes, while the xylem pressure causing 88% loss of hydraulic conductivity (P88 value) was more closely related to hydraulic efficiency than the commonly used P50 value. Deme-specific variation in the pit membrane structure may explain why vessel size was not directly linked to growth rate. We conclude that branch hydraulic efficiency is an important growth-influencing trait in aspen, while the assumed trade-off between productivity and hydraulic safety is weak. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Relationship between the Decomposition Process of Coarse Woody Debris and Fungal Community Structure as Detected by High-Throughput Sequencing in a Deciduous Broad-Leaved Forest in Japan

PubMed Central

Yamashita, Satoshi; Masuya, Hayato; Abe, Shin; Masaki, Takashi; Okabe, Kimiko

2015-01-01

We examined the relationship between the community structure of wood-decaying fungi, detected by high-throughput sequencing, and the decomposition rate using 13 years of data from a forest dynamics plot. For molecular analysis and wood density measurements, drill dust samples were collected from logs and stumps of Fagus and Quercus in the plot. Regression using a negative exponential model between wood density and time since death revealed that the decomposition rate of Fagus was greater than that of Quercus. The residual between the expected value obtained from the regression curve and the observed wood density was used as a decomposition rate index. Principal component analysis showed that the fungal community compositions of both Fagus and Quercus changed with time since death. Principal component analysis axis scores were used as an index of fungal community composition. A structural equation model for each wood genus was used to assess the effect of fungal community structure traits on the decomposition rate and how the fungal community structure was determined by the traits of coarse woody debris. Results of the structural equation model suggested that the decomposition rate of Fagus was affected by two fungal community composition components: one that was affected by time since death and another that was not affected by the traits of coarse woody debris. In contrast, the decomposition rate of Quercus was not affected by coarse woody debris traits or fungal community structure. These findings suggest that, in the case of Fagus coarse woody debris, the fungal community structure is related to the decomposition process of its host substrate. Because fungal community structure is affected partly by the decay stage and wood density of its substrate, these factors influence each other. Further research on interactive effects is needed to improve our understanding of the relationship between fungal community structure and the woody debris decomposition process. PMID:26110605
Ten-year performance of treated northeastern softwoods in aboveground and ground-contact exposures

Treesearch

Douglas M. Crawford; Rodney C. De Groot; Lee R. Gjovik

The commercial value of several softwood species of the northeastern United States could be increased if these woods could be treated to meet existing American Wood Preserversa Association (AWPA) Standards and used in durable structures. We evaluated the long-term durability of incised and unincised white pine, red pine, eastern spruce, balsam fir, and eastern hemlock...
Resistance of borax–copper treated wood in aboveground exposure to attack by Formosan subterranean termites

Treesearch

Stan Lebow; Bessie Woodward; Douglas Crawford; William Abbott

2005-01-01

The spread of Formosan subterranean termites (FSTs) in the southern United States has increased public interest in finding a preservative treatment to protect framing lumber from termite attack. This study evaluated the use of a borax-based preservative to protect wood from FST attack. Southern Pine and Douglas-fir specimens were pressure-treated with three...
Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests

DOE PAGES

Wagner, Fabien H.; Hérault, Bruno; Bonal, Damien; ...

2016-04-28

Here, the seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combination of seasonal pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measurements and 35 litter productivity measurements), their associated canopy photosynthetic capacity (enhanced vegetation index, EVI) and climate, we ask how carbon assimilation and aboveground allocation are related to climate seasonality in tropical forests and how they interact in the seasonal carbon cycle. We found that canopy photosynthetic capacity seasonality responds positivelymore » to precipitation when rainfall is < 2000 mm yr -1 (water-limited forests) and to radiation otherwise (light-limited forests). On the other hand, independent of climate limitations, wood productivity and litterfall are driven by seasonal variation in precipitation and evapotranspiration, respectively. Consequently, light-limited forests present an asynchronism between canopy photosynthetic capacity and wood productivity. First-order control by precipitation likely indicates a decrease in tropical forest productivity in a drier climate in water-limited forest, and in current light-limited forest with future rainfall < 2000 mm yr -1.« less
Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagner, Fabien H.; Hérault, Bruno; Bonal, Damien

Here, the seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combination of seasonal pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measurements and 35 litter productivity measurements), their associated canopy photosynthetic capacity (enhanced vegetation index, EVI) and climate, we ask how carbon assimilation and aboveground allocation are related to climate seasonality in tropical forests and how they interact in the seasonal carbon cycle. We found that canopy photosynthetic capacity seasonality responds positivelymore » to precipitation when rainfall is < 2000 mm yr -1 (water-limited forests) and to radiation otherwise (light-limited forests). On the other hand, independent of climate limitations, wood productivity and litterfall are driven by seasonal variation in precipitation and evapotranspiration, respectively. Consequently, light-limited forests present an asynchronism between canopy photosynthetic capacity and wood productivity. First-order control by precipitation likely indicates a decrease in tropical forest productivity in a drier climate in water-limited forest, and in current light-limited forest with future rainfall < 2000 mm yr -1.« less
A simple method for estimating gross carbon budgets for vegetation in forest ecosystems.

PubMed

Ryan, Michael G.

1991-01-01

Gross carbon budgets for vegetation in forest ecosystems are difficult to construct because of problems in scaling flux measurements made on small samples over short periods of time and in determining belowground carbon allocation. Recently, empirical relationships have been developed to estimate total belowground carbon allocation from litterfall, and maintenance respiration from tissue nitrogen content. I outline a method for estimating gross carbon budgets using these empirical relationships together with data readily available from ecosystem studies (aboveground wood and canopy production, aboveground wood and canopy biomass, litterfall, and tissue nitrogen contents). Estimates generated with this method are compared with annual carbon fixation estimates from the Forest-BGC model for a lodgepole pine (Pinus contorta Dougl.) and a Pacific silver fir (Abies amabilis Dougl.) chronosequence.
Biomass, production and woody detritus in an old coast redwood (Sequoia sempervirens) forest

USGS Publications Warehouse

Busing, R.T.; Fujimori, T.

2005-01-01

We examined aboveground biomass dynamics, aboveground net primary production (ANPP), and woody detritus input in an old Sequoia sempervirens stand over a three-decade period. Our estimates of aboveground biomass ranged from 3300 to 5800 Mg ha-1. Stem biomass estimates ranged from 3000 to 5200 Mg ha-1. Stem biomass declined 7% over the study interval. Biomass dynamics were patchy, with marked declines in recent tree-fall patches <0.05 ha in size. Larger tree-fall patches approaching 0.2 ha in size were observed outside the study plot. Our estimates of ANPP ranged from 6 to 14 Mg ha -1yr-1. Estimates of 7 to 10 Mg ha-1yr -1 were considered to be relatively accurate. Thus, our estimates based on long-term data corroborated the findings of earlier short-term studies. ANPP of old, pure stands of Sequoia was not above average for temperate forests. Even though production was potentially high on a per stem basis, it was moderate at the stand level. We obtained values of 797 m3 ha -1 and 262 Mg ha-1 for coarse woody detritus volume and mass, respectively. Fine woody detritus volume and mass were estimated at 16 m3 ha-1 and 5 Mg ha-1, respectively. Standing dead trees (or snags) comprised 7% of the total coarse detritus volume and 8% of the total mass. Coarse detritus input averaged 5.7 to 6.9 Mg ha -1yr-1. Assuming steady-state input and pool of coarse detritus, we obtained a decay rate constant of 0.022 to 0.026. The old-growth stand of Sequoia studied had extremely high biomass, but ANPP was moderate and the amount of woody detritus was not exceptionally large. Biomass accretion and loss were not rapid in this stand partly because of the slow population dynamics and low canopy turnover rate of Sequoia at the old-growth stage. Nomenclature: Hickman (1993). ?? Springer 2005.
The fine scale physical attributes of coarse woody debris and effects of surrounding stand structure on its utilization by ants (Hymenoptera: Formicidae) in British Columbia, Canada

Treesearch

Robert J. Higgins; B. Staffan Lindgren

2006-01-01

Coarse woody debris (CWD) is increasingly recognized in Canada for its contribution toward biodiversity. It is a particularly vital resource in subboreal forests as nesting habitat for ants (Formicidae). Wood, which has low specific heat, provides a thermally favorable environment in this cool climate. Ants contribute to the physical breakdown of wood, and colonies are...
Aboveground Biomass of Choctawhatchee Sand Pine in Northwest Florida

Treesearch

Michael A. Taras

1980-01-01

Choctawhatchee sand pine trees 4 to 14 inches d.b.h. were selected from a natural, uneven-aged stand in northwest Florida to determine the weight and volume of above ground biomass. On the average, 85 percent of the green weight of the total tree was wood, 11 percent bark. and 4 percent needles. The average tree sampled had 82 percent of its wood in the stem and 18...
Consequences of long-term severe industrial pollution for aboveground carbon and nitrogen pools in northern taiga forests at local and regional scales.

PubMed

Manninen, Sirkku; Zverev, Vitali; Bergman, Igor; Kozlov, Mikhail V

2015-12-01

Boreal coniferous forests act as an important sink for atmospheric carbon dioxide. The overall tree carbon (C) sink in the forests of Europe has increased during the past decades, especially due to management and elevated nitrogen (N) deposition; however, industrial atmospheric pollution, primarily sulphur dioxide and heavy metals, still negatively affect forest biomass production at different spatial scales. We report local and regional changes in forest aboveground biomass, C and N concentrations in plant tissues, and C and N pools caused by long-term atmospheric emissions from a large point source, the nickel-copper smelter in Monchegorsk, in north-western Russia. An increase in pollution load (assessed as Cu concentration in forest litter) caused C to increase in foliage but C remained unchanged in wood, while N decreased in foliage and increased in wood, demonstrating strong effects of pollution on resource translocation between green and woody tissues. The aboveground C and N pools were primarily governed by plant biomass, which strongly decreased with an increase in pollution load. In our study sites (located 1.6-39.7 km from the smelter) living aboveground plant biomass was 76 to 4888 gm(-2), and C and N pools ranged 35-2333 g C m(-2) and 0.5-35.1 g N m(-2), respectively. We estimate that the aboveground plant biomass is reduced due to chronic exposure to industrial air pollution over an area of about 107,200 km2, and the total (aboveground and belowground) loss of phytomass C stock amounts to 4.24×10(13) g C. Our results emphasize the need to account for the overall impact of industrial polluters on ecosystem C and N pools when assessing the C and N dynamics in northern boreal forests because of the marked long-term negative effects of their emissions on structure and productivity of plant communities. Copyright © 2015 Elsevier B.V. All rights reserved.
The sweet side of global change-dynamic responses of non-structural carbohydrates to drought, elevated CO2 and nitrogen fertilization in tree species.

PubMed

Li, Weibin; Hartmann, Henrik; Adams, Henry D; Zhang, Hongxia; Jin, Changjie; Zhao, Chuanyan; Guan, Dexin; Wang, Anzhi; Yuan, Fenghui; Wu, Jiabing

2018-06-11

Non-structural carbohydrates (NSC) play a central role in plant functioning as energy carriers and building blocks for primary and secondary metabolism. Many studies have investigated how environmental and anthropogenic changes, like increasingly frequent and severe drought episodes, elevated CO2 and atmospheric nitrogen (N) deposition, influence NSC concentrations in individual trees. However, this wealth of data has not been analyzed yet to identify general trends using a common statistical framework. A thorough understanding of tree responses to global change is required for making realistic predictions of vegetation dynamics. Here we compiled data from 57 experimental studies on 71 tree species and conducted a meta-analysis to evaluate general responses of stored soluble sugars, starch and total NSC (soluble sugars + starch) concentrations in different tree organs (foliage, above-ground wood and roots) to drought, elevated CO2 and N deposition. We found that drought significantly decreased total NSC in roots (-17.3%), but not in foliage and above-ground woody tissues (bole, branch, stem and/or twig). Elevated CO2 significantly increased total NSC in foliage (+26.2%) and roots (+12.8%), but not in above-ground wood. By contrast, total NSC significantly decreased in roots (-17.9%), increased in above-ground wood (+6.1%), but was unaffected in foliage from N fertilization. In addition, the response of NSC to three global change drivers was strongly affected by tree taxonomic type, leaf habit, tree age and treatment intensity. Our results pave the way for a better understanding of general tree function responses to drought, elevated CO2 and N fertilization. The existing data also reveal that more long-term studies on mature trees that allow testing interactions between these factors are urgently needed to provide a basis for forecasting tree responses to environmental change at the global scale.
Invertebrates Associated with Coarse Woody Debris in Streams, Upland Forests, and Wetlands: A Review

Treesearch

A. Braccia; D.P. Batzer

1999-01-01

We reviewed literature on the inbvertebrate groups associated with coarse woody debris in forests, streams, and wetlands, and contrasted patterns of invertebrate community development and wood decomposition among ecosystems.
Tree allometry and improved estimation of carbon stocks and balance in tropical forests.

PubMed

Chave, J; Andalo, C; Brown, S; Cairns, M A; Chambers, J Q; Eamus, D; Fölster, H; Fromard, F; Higuchi, N; Kira, T; Lescure, J-P; Nelson, B W; Ogawa, H; Puig, H; Riéra, B; Yamakura, T

2005-08-01

Tropical forests hold large stores of carbon, yet uncertainty remains regarding their quantitative contribution to the global carbon cycle. One approach to quantifying carbon biomass stores consists in inferring changes from long-term forest inventory plots. Regression models are used to convert inventory data into an estimate of aboveground biomass (AGB). We provide a critical reassessment of the quality and the robustness of these models across tropical forest types, using a large dataset of 2,410 trees >or= 5 cm diameter, directly harvested in 27 study sites across the tropics. Proportional relationships between aboveground biomass and the product of wood density, trunk cross-sectional area, and total height are constructed. We also develop a regression model involving wood density and stem diameter only. Our models were tested for secondary and old-growth forests, for dry, moist and wet forests, for lowland and montane forests, and for mangrove forests. The most important predictors of AGB of a tree were, in decreasing order of importance, its trunk diameter, wood specific gravity, total height, and forest type (dry, moist, or wet). Overestimates prevailed, giving a bias of 0.5-6.5% when errors were averaged across all stands. Our regression models can be used reliably to predict aboveground tree biomass across a broad range of tropical forests. Because they are based on an unprecedented dataset, these models should improve the quality of tropical biomass estimates, and bring consensus about the contribution of the tropical forest biome and tropical deforestation to the global carbon cycle.
Long-term dead wood changes in a Sierra Nevada mixed conifer forest: habitat and fire hazard implications

Treesearch

Eric E. Knapp

2015-01-01

Dead trees play an important role in forests, with snags and coarse woody debris (CWD) used by many bird and mammal species for nesting, resting, or foraging. However, too much dead wood can also contribute to extreme fire behavior. This tension between dead wood as habitat and dead wood as fuel has raised questions about appropriate quantities in fire-dependent...
Generation rate and particle size distribution of wood dust by handheld sanding operation.

PubMed

Ojima, Jun

2016-11-29

The International Agency for Research on Cancer (IARC) and Japan Society for Occupational Health (JSOH) classified wood dust as a human carcinogen. Former studies have suggested that sanding with a portable sander is one of the processes that are liable to cause highest exposure to wood dust. However, the wood dust by sanding operation has not been investigated sufficiently. In this study, the generation rate and the particle size distribution of the wood dust produced by handheld sanding operation were observed by laboratory experiments. Beech and cypress were taken as typical hard and soft wood specimen respectively, and sanded with a portable sander. Three grades of sand paper (coarse, medium, fine) were attached to the sander in turn to be tested. The quantity of the wood dust produced by the sander was measured by weighing the specimen before and after the sanding and then the generation rate of the dust was calculated. Soft wood generated more dust than hard wood due to the difference in abrasion durability. A coarse sand paper produced more dust than a fine sand paper. The particles of less than 1 μm diameter were scarcely observed in the wood dust. When the specimens were sanded with a fine sand paper, the mass median aerodynamic diameters of beech dust and cypress dust were 9.0 μm and 9.8 μm, respectively. Respirable wood dust is able to be controlled by general ventilation with more than 0.7-4.2 m 3 /min ventilation rate.
Does the presence of large down wood at the time of a forest fire impact soil recovery?

Treesearch

Jane E. Smith; Laurel A. Kluber; Tara N. Jennings; Donaraye McKay; Greg Brenner; Elizabeth W. Sulzman

2017-01-01

Fire may remove or create dead wood aboveground, but it is less clear how high severity burning of soils affects belowground microbial communities and soil processes, and for how long. In this study, we investigated soil fungal and bacterial communities and biogeochemical responses of severely burned ââredâ soil and less severely burned ââblackâ soil from a burned...
Converting wood volume to biomass for pinyon and juniper. Forest Service research note

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chojnacky, D.C.; Moisen, G.G.

1993-03-01

A technique was developed to convert pinyon-juniper volume equation predictions to weights. The method uses specific gravity and biomass conversion equations to obtain foliage weight and total wood weight of all stems, branches, and bark. Specific gravity data are given for several Arizona pinyon-juniper species. Biomass conversion equations are constructed from pinyon-juniper data collected in Nevada. Results provide an interim means of estimating pinyon-juniper aboveground biomass from available volume inventory data.
Quantifying uncertainty in carbon and nutrient pools of coarse woody debris

NASA Astrophysics Data System (ADS)

See, C. R.; Campbell, J. L.; Fraver, S.; Domke, G. M.; Harmon, M. E.; Knoepp, J. D.; Woodall, C. W.

2016-12-01

Woody detritus constitutes a major pool of both carbon and nutrients in forested ecosystems. Estimating coarse wood stocks relies on many assumptions, even when full surveys are conducted. Researchers rarely report error in coarse wood pool estimates, despite the importance to ecosystem budgets and modelling efforts. To date, no study has attempted a comprehensive assessment of error rates and uncertainty inherent in the estimation of this pool. Here, we use Monte Carlo analysis to propagate the error associated with the major sources of uncertainty present in the calculation of coarse wood carbon and nutrient (i.e., N, P, K, Ca, Mg, Na) pools. We also evaluate individual sources of error to identify the importance of each source of uncertainty in our estimates. We quantify sampling error by comparing the three most common field methods used to survey coarse wood (two transect methods and a whole-plot survey). We quantify the measurement error associated with length and diameter measurement, and technician error in species identification and decay class using plots surveyed by multiple technicians. We use previously published values of model error for the four most common methods of volume estimation: Smalian's, conical frustum, conic paraboloid, and average-of-ends. We also use previously published values for error in the collapse ratio (cross-sectional height/width) of decayed logs that serves as a surrogate for the volume remaining. We consider sampling error in chemical concentration and density for all decay classes, using distributions from both published and unpublished studies. Analytical uncertainty is calculated using standard reference plant material from the National Institute of Standards. Our results suggest that technician error in decay classification can have a large effect on uncertainty, since many of the error distributions included in the calculation (e.g. density, chemical concentration, volume-model selection, collapse ratio) are decay-class specific.

Generation rate and particle size distribution of wood dust by handheld sanding operation

PubMed Central

Ojima, Jun

2016-01-01

Objectives: The International Agency for Research on Cancer (IARC) and Japan Society for Occupational Health (JSOH) classified wood dust as a human carcinogen. Former studies have suggested that sanding with a portable sander is one of the processes that are liable to cause highest exposure to wood dust. However, the wood dust by sanding operation has not been investigated sufficiently. In this study, the generation rate and the particle size distribution of the wood dust produced by handheld sanding operation were observed by laboratory experiments. Methods: Beech and cypress were taken as typical hard and soft wood specimen respectively, and sanded with a portable sander. Three grades of sand paper (coarse, medium, fine) were attached to the sander in turn to be tested. The quantity of the wood dust produced by the sander was measured by weighing the specimen before and after the sanding and then the generation rate of the dust was calculated. Results: Soft wood generated more dust than hard wood due to the difference in abrasion durability. A coarse sand paper produced more dust than a fine sand paper. The particles of less than 1 μm diameter were scarcely observed in the wood dust. When the specimens were sanded with a fine sand paper, the mass median aerodynamic diameters of beech dust and cypress dust were 9.0 μm and 9.8 μm, respectively. Conclusions: Respirable wood dust is able to be controlled by general ventilation with more than 0.7-4.2 m3/min ventilation rate. PMID:27725491
Evaluating the efficacy of wood shreds for mitigating erosion

Treesearch

Randy B. Foltz; Natalie S. Copeland

2009-01-01

An erosion control product made by shredding on-site woody materials was evaluated for mitigating erosion through a series of rainfall simulations. Tests were conducted on bare soil and soil with 30, 50, and 70% cover on a coarse and a fine-grained soil. Results indicated that the wood product known as wood shreds reduced runoff and soil loss from both soil types....
Chemical characterization of size-segregated PM from different public transport modes and implications of source specific contribution to public exposure.

PubMed

Jiang, Sabrina Yanan; Gali, Nirmal Kumar; Yang, Fenhuan; Zhang, Junke; Ning, Zhi

2017-08-01

To investigate the chemical properties of particulate matter (PM) in different public transport microenvironments in Hong Kong, the coarse (2.5-10 μm) and fine (<2.5 μm) PM samples were collected in three different types of transport modes including Mass Transit Railway (MTR)-Aboveground (AG), MTR Underground (UG), and Bus routes from October 2013 to April 2014. Average PM 2.5 concentrations through UG, AG, and Bus routes were 47.9, 86.8, and 43.8 μg m -3 , respectively, whereas the coarse PM concentrations were 4-5 folds less. The PM 2.5 total metal concentrations of AG route were 2.3 and 3.7 times of UG and BUS routes, respectively, compared to those in the other two routes. The most abundant metals at three stations in PM 2.5 and coarse PM were quite similar and mainly generated by frictional processes of wheels, rails, and brakes of the system as well as by the mechanical wearing of these parts. The most abundant PAH in three routes in PM 2.5 was ATRQN, followed by 2-MNA, and the sum of them contributed to 35 and 42% of total PAHs in coarse PM and PM 2.5 , respectively. Crude oils, lubricant oil, diesel emissions would be the major sources of PAHs from MTR aboveground stations. The relative abundance of the n-alkanes among different samples was similar to the PAHs and the carbon preference index (CPI) values of the whole n-alkanes range were consistently from 0.99 to 1.04 among all samples indicating the significant contribution from the vehicle exhaust and fossil fuel burning. The concentrations of hopanes and steranes were higher in PM 2.5 than in coarse PM due to diesel and coal burning. These results may provide a unique opportunity to investigate source specific contribution of the PM pollutants to the commuter exposure in public transport.
Downed wood as seedbed: measurement and management guidelines

Treesearch

Mark J. Ducey; Jeffrey H. Gove

2000-01-01

Eastern hemlock has exacting germination requirements, and availability of suitable microsites for germination can limit the development of hemlock regeneration. A major contributor to those microsites is coarse woody debris. New methods for quantifying coarse woody debris have recently been developed that are complementary to strategies typically used in timber...
Detecting wood surface defects with fusion algorithm of visual saliency and local threshold segmentation

NASA Astrophysics Data System (ADS)

Wang, Xuejuan; Wu, Shuhang; Liu, Yunpeng

2018-04-01

This paper presents a new method for wood defect detection. It can solve the over-segmentation problem existing in local threshold segmentation methods. This method effectively takes advantages of visual saliency and local threshold segmentation. Firstly, defect areas are coarsely located by using spectral residual method to calculate global visual saliency of them. Then, the threshold segmentation of maximum inter-class variance method is adopted for positioning and segmenting the wood surface defects precisely around the coarse located areas. Lastly, we use mathematical morphology to process the binary images after segmentation, which reduces the noise and small false objects. Experiments on test images of insect hole, dead knot and sound knot show that the method we proposed obtains ideal segmentation results and is superior to the existing segmentation methods based on edge detection, OSTU and threshold segmentation.
Partial dissolution of ACQ-treated wood in lithium chloride/N-methyl-2-pyrrolidinone: Separation of copper from potential lignocellulosic feedstocks

Treesearch

Thomas L. Eberhardt; Stan Lebow; Karen G. Reed

2012-01-01

A cellulose solvent system based on lithium chloride (LiCl) in N-methyl-2-pyrrolidinone (NMP) was used to assess the merits of partial dissolutions of coarsely ground wood samples. Alkaline Copper Quaternary (ACQ)-treated pine wood was of particular interest for treatment given the potential to generate a copper- rich stream apart from solid and/or liquid...
Can we relate respiration rates of bark and wood with tissue nitrogen concentrations and branch-level CO2 fluxes across woody species?

NASA Astrophysics Data System (ADS)

Eller, A. S.; Wright, I.; Cernusak, L. A.

2013-12-01

Respiration from above-ground woody tissue is generally responsible for 5-15% of ecosystem respiration (~ 30% of total above-ground respiration). The CO2 respired by branches comes from both the sapwood and the living layers within the bark, but because there is considerable movement of respired CO2 within woody tissues (e.g. in the transpiration stream), and because the bark can present a considerable barrier to CO2 diffusion, it can be difficult to interpret measured CO2 efflux from intact branches in relation to the respiration rates of the component tissues, and to relative mass allocation to each. In this study we investigated these issues in 15 evergreen tree and shrub species native to the Sydney area in eastern Australia. We measured CO2 efflux and light-dependent refixation of respired CO2 in photosynthetic bark from the exterior surfaces of branches (0.5-1.5 cm in diameter), and measured the tissue-specific respiration rates of the bark and wood from those same branches. We also measured the nitrogen content and tissue density of the wood and bark to determine: 1) Among species, what is the relationship between %N and tissue respiration? 2) How is photosynthetic refixation of CO2 related to respiration and %N in the bark and underlying wood? and 3) What is the relationship between branch CO2 efflux and the respiration rates of the underlying wood and bark that make up the branch? Across the 15 species %N was a better predictor of respiration in wood than in bark. CO2 efflux measured from the exterior of the stem in the dark was positively correlated with photosynthetic refixation and explained ~40% of the variation in rates of refixation. Refixation rates were not strongly related to bark or wood %N. Differences among species in CO2 efflux rates were not well explained by differences in bark or wood %N and there was a stronger relationship between bark respiration and CO2 efflux than between wood respiration and CO2 efflux. These results suggest that the CO2 efflux rates measured on branch exterior surfaces may be driven more strongly by bark respiration than wood respiration and a better understanding of bark respiration will increase our ability to predict CO2 efflux from branches
Compatible above-ground biomass equations and carbon stock estimation for small diameter Turkish pine (Pinus brutia Ten.).

PubMed

Sakici, Oytun Emre; Kucuk, Omer; Ashraf, Muhammad Irfan

2018-04-15

Small trees and saplings are important for forest management, carbon stock estimation, ecological modeling, and fire management planning. Turkish pine (Pinus brutia Ten.) is a common coniferous species and comprises 25.1% of total forest area of Turkey. Turkish pine is also important due to its flammable fuel characteristics. In this study, compatible above-ground biomass equations were developed to predict needle, branch, stem wood, and above-ground total biomass, and carbon stock assessment was also described for Turkish pine which is smaller than 8 cm diameter at breast height or shorter than breast height. Compatible biomass equations are useful for biomass prediction of small diameter individuals of Turkish pine. These equations will also be helpful in determining fire behavior characteristics and calculating their carbon stock. Overall, present study will be useful for developing ecological models, forest management plans, silvicultural plans, and fire management plans.
Intra-annual changes in biomass, carbon, and nitrogen dynamics at 4-year old switchgrass field trials in West Tennessee, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garten, Jr, C. T.; Smith, Jeffery L.; Tyler, Donald D.

2010-02-15

Switchgrass is a potential bioenergy crop that could promote soil C sequestration in some environments. We compared four cultivars on a well-drained Alfisol to test for differences in biomass, C, and N dynamics during the fourth growing season. There was no difference (P > 0.05) among cultivars and no significant cultivar x time interaction in analyses of dry mass, C stocks, or N stocks in aboveground biomass and surface litter. At the end of the growing season, mean (±SE) aboveground biomass was 2.1±0.13 kg m-2, and surface litter dry mass was approximately 50% of aboveground biomass. Prior to harvest, themore » live root:shoot biomass ratio was 0.76. There was no difference (P > 0.05) among cultivars for total biomass, C, and N stocks belowground. Total belowground biomass (90-cm soil depth) as well as coarse (greater than or equal to 1 mm diameter) and fine (< 1 mm diameter) live root biomass increased from April to October. Dead roots were less than 7% of live root biomass to a depth of 90 cm. Net production of total belowground biomass (505 ±132 g m-2) occurred in the last half of the growing season. The increase in total live belowground biomass (426 ±139 g m-2) was more or less evenly divided among rhizomes, coarse, and fine roots. The N budget for annual switchgrass production was closely balanced with 6.3 g N m-2 removed by harvest of aboveground biomass and 6.7 g N m-2 supplied by fertilization. At the location of our study in west Tennessee, intra-annual changes in biomass, C, and N stocks belowground were of greater importance to crop management for C sequestration than were differences among cultivars.« less
The role of moisture content in above-ground leaching

Treesearch

Stan Lebow; Patricia Lebow

2007-01-01

This paper reviews previous reports on the moisture content of wood exposed above ground and compares those values to moisture contents obtained using simulated rainfall and immersion methods. Laboratory leaching trials with CCA-treated specimens were also conducted and the results compared to published values for leaching of CCA-treated specimens exposed above ground...
Data for developing allometric models and evaluating carbon stocks of the Zambezi Teak Forests in Zambia.

PubMed

Ngoma, Justine; Moors, Eddy; Kruijt, Bart; Speer, James H; Vinya, Royd; Chidumayo, Emmanuel N; Leemans, Rik

2018-04-01

This paper presents data on carbon stocks of tropical tree species along a rainfall gradient. The data was generated from the Sesheke, Namwala, and Kabompo sites in Zambia. Though above-ground data was generated for all these three sites, we uprooted trees to determine below-ground biomass from the Sesheke site only. The vegetation was assessed in all three sites. The data includes tree diameter at breast height (DBH), total tree height, wood density, wood dry weight and root dry weight for large (≥ 5 cm DBH) and small (< 5 cm DBH) trees. We further presented Root-to-Shoot Ratios of uprooted trees. Data on the importance-value indices of various species for large and small trees are also determined. Below and above-ground carbon stocks of the surveyed tree species are presented per site. This data were used by Ngoma et al. (2018) [1] to develop above and below-ground biomass models and the reader is referred to this study for additional information, interpretation, and reflection on applying this data.
Decomposition rates of American chestnut (Castanea dentata) wood and implications for coarse woody debris pools

Treesearch

Arjan de Bruijn; Eric J. Gustafson; Daniel M. Kashian; Harmony J. Dalgleish; Brian R. Sturtevant; Douglass F. Jacobs

2014-01-01

Observations of the rapid growth and slow decomposition of American chestnut (Castanea dentata (Marsh.) Borkh.) suggest that its reintroduction could enhance terrestrial carbon (C) sequestration. A suite of decomposition models was fit with decomposition data from coarse woody debris (CWD) sampled in Wisconsin and Virginia, U.S. The optimal (two-...
Spatial Distribution of Aboveground Carbon Stock of the Arboreal Vegetation in Brazilian Biomes of Savanna, Atlantic Forest and Semi-Arid Woodland.

PubMed

Scolforo, Henrique Ferraco; Scolforo, Jose Roberto Soares; Mello, Carlos Rogerio; Mello, Jose Marcio; Ferraz Filho, Antonio Carlos

2015-01-01

The objective of this study was to map the spatial distribution of aboveground carbon stock (using Regression-kriging) of arboreal plants in the Atlantic Forest, Semi-arid woodland, and Savanna Biomes in Minas Gerais State, southeastern Brazil. The database used in this study was obtained from 163 forest fragments, totaling 4,146 plots of 1,000 m2 distributed in these Biomes. A geographical model for carbon stock estimation was parameterized as a function of Biome, latitude and altitude. This model was applied over the samples and the residuals generated were mapped based on geostatistical procedures, selecting the exponential semivariogram theoretical model for conducting ordinary Kriging. The aboveground carbon stock was found to have a greater concentration in the north of the State, where the largest contingent of native vegetation is located, mainly the Savanna Biome, with Wooded Savanna and Shrub Savanna phytophysiognomes. The largest weighted averages of carbon stock per hectare were found in the south-center region (48.6 Mg/ha) and in the southern part of the eastern region (48.4 Mg/ha) of Minas Gerais State, due to the greatest predominance of Atlantic Forest Biome forest fragments. The smallest weighted averages per hectare were found in the central (21.2 Mg/ha), northern (20.4 Mg/ha), and northwestern (20.7 Mg/ha) regions of Minas Gerais State, where Savanna Biome fragments are predominant, in the phytophysiognomes Wooded Savanna and Shrub Savanna.
Spatial Distribution of Aboveground Carbon Stock of the Arboreal Vegetation in Brazilian Biomes of Savanna, Atlantic Forest and Semi-Arid Woodland

PubMed Central

2015-01-01

The objective of this study was to map the spatial distribution of aboveground carbon stock (using Regression-kriging) of arboreal plants in the Atlantic Forest, Semi-arid woodland, and Savanna Biomes in Minas Gerais State, southeastern Brazil. The database used in this study was obtained from 163 forest fragments, totaling 4,146 plots of 1,000 m2 distributed in these Biomes. A geographical model for carbon stock estimation was parameterized as a function of Biome, latitude and altitude. This model was applied over the samples and the residuals generated were mapped based on geostatistical procedures, selecting the exponential semivariogram theoretical model for conducting ordinary Kriging. The aboveground carbon stock was found to have a greater concentration in the north of the State, where the largest contingent of native vegetation is located, mainly the Savanna Biome, with Wooded Savanna and Shrub Savanna phytophysiognomes. The largest weighted averages of carbon stock per hectare were found in the south-center region (48.6 Mg/ha) and in the southern part of the eastern region (48.4 Mg/ha) of Minas Gerais State, due to the greatest predominance of Atlantic Forest Biome forest fragments. The smallest weighted averages per hectare were found in the central (21.2 Mg/ha), northern (20.4 Mg/ha), and northwestern (20.7 Mg/ha) regions of Minas Gerais State, where Savanna Biome fragments are predominant, in the phytophysiognomes Wooded Savanna and Shrub Savanna. PMID:26066508
Biomass yielding potential of naturally regenerated Prosopis juliflora tree stands at three varied ecosystems in southern districts of Tamil Nadu, India.

PubMed

Saraswathi, K; Chandrasekaran, S

2016-05-01

Fuel energy demand is of great concern in recent times due to the depletion of fossil fuel resources. Biomass serves as widely available primary renewable energy source. Hence, a study was performed to assess the above-ground biomass yielding capability of fuel wood tree Prosopis juliflora in three varied ecosystems viz., coastal, fallow land and riparian ecosystems in southern districts of Tamil Nadu. The results showed that the biomass production potential and above-ground net primary productivity of P. juliflora depend on the age of the tree stands and the nature of ecosystem. A higher biomass yield was observed for P. juliflora trees with 5 to 10 years old when compared to less than 5 years of their age. Among the three ecosystems, the maximum biomass production was recorded in riparian ecosystem. The stands with less than 5-year-old P. juliflora trees gave 1.40 t/ha, and 5- to 10-year-old tree stands produced 27.69 t/ha in riparian ecosystem. Above-ground net primary productivity of both the age groups was high in fallow land ecosystem. In riparian ecosystem, the wood showed high density and low sulphur content than the other two ecosystems. Hence, P. juliflora biomass can serve as an environmentally and economically feasible fuel as well as their utilization proffers an effective means to control its invasiveness.
Responses of arthropods to large-scale manipulations of dead wood in loblolly pine stands of the southeastern United States.

PubMed

Ulyshen, Michael D; Hanula, James L

2009-08-01

Large-scale experimental manipulations of dead wood are needed to better understand its importance to animal communities in managed forests. In this experiment, we compared the abundance, species richness, diversity, and composition of arthropods in 9.3-ha plots in which either (1) all coarse woody debris was removed, (2) a large number of logs were added, (3) a large number of snags were added, or (4) no coarse woody debris was added or removed. The target taxa were ground-dwelling arthropods, sampled by pitfall traps, and saproxylic beetles (i.e., dependent on dead wood), sampled by flight intercept traps and emergence traps. There were no differences in total ground-dwelling arthropod abundance, richness, diversity, or composition among treatments. Only the results for ground beetles (Carabidae), which were more species rich and diverse in log input plots, supported our prediction that ground-dwelling arthropods would benefit from additions of dead wood. There were also no differences in saproxylic beetle abundance, richness, diversity, or composition among treatments. The findings from this study are encouraging in that arthropods seem less sensitive than expected to manipulations of dead wood in managed pine forests of the southeastern United States. Based on our results, we cannot recommend inputting large amounts of dead wood for conservation purposes, given the expense of such measures. However, the persistence of saproxylic beetles requires that an adequate amount of dead wood is available in the landscape, and we recommend that dead wood be retained whenever possible in managed pine forests.
Specific features of the recent accumulation of 137Cs in tree roots of forest ecosystems within the zone of radioactive contamination

NASA Astrophysics Data System (ADS)

Shcheglov, Alexey; Tsvetnova, Ol'ga; Klyashtorin, Alexey; Popova, Evgenia

2015-04-01

Despite numerous studies of the accumulation of technogenic radionuclides in the root systems, no clear regularities of this process have been established. The tendencies found in the works of Russian and foreign researchers are rather discrepant. Some authors argue that the accumulation of radionuclides in the roots is more pronounced than that in the aboveground parts of the plants (Skovorodnikova, 2005; Romantseva, 2012; Sennerby et al., 1994; Mamikhin, 2002; Fircks et al., 2002}. Other works attest to a higher accumulation of radionuclides in the aboveground pars (Juznic et al., 1990; Chibowski, 2000; Zhianski et al., 2005), which is also typical of the stable isotopes of these elements, including 133Cs (Dong Jin Kang, YongJin Seo, Tsukasa Saito et al,2012). It is also stated that the accumulation of radionuclides in the aboveground and underground parts of plants may differ in dependence on the soil-ecological conditions and other factors (Kozhakhanov et al., 2011; Grabovskyi et al., 2013). The aim of our study was to evaluate the accumulation of 137Cs in the root systems of arboreal plants in forest ecosystems within the near zone of the Chernobyl fallout on the plots with similar soil and phytocenotic features. Pine and birch stands were studied within the 30-km-wide exclusion zone of the Chernobyl Nuclear Power Station in Ukraine in 1992-1993, when the density of the radioactive contamination of the upper (0-20 cm) layer with 137Cs reached 2153.8 kBq/m2), and in Bryansk oblast of Russia in 2013-2014, when the density of contamination varied from 1458.4 kBq/m2 (pine stand) to 2578.3 kBq/m2 (birch stand). The tree layer in these ecosystems was dominated by Pinus sylvestris (L.) and Betula pendula (Roth.), respectively. Quercus robur (L.), Picea abies (L.), and Sorbus aucuparia (L.) were also present. The specific activity of 137Cs was measured in the samples from the aboveground parts of model trees and their roots differentiated by size (0-3, 3-10, 10-20, and > 20 mm), and 10-cm-deep soil horizons down to the depth of 70 cm. At the initial stage of our studies (in 1992-1993), we found that the mean weighted values of the specific activity of 137Cs in the roots was 1.5-2.0 times higher than that in the aboveground parts of the trees and also exceeded the specific activity in the adjacent soil mass. These differences increased with the depth: the activity of the roots was two times higher in the upper 10 cm and up to 100 times higher in the layer of 30-70 cm (Shcheglov, 1999; Rafferty, Kliashtorin, Kuchma, Ruehm, Shcheglov, 1996; Shcheglov, Tsvetnova, Kliashtorin, 2001). The studies performed in 2013-2014 the stage of active uptake by the roots is characterized by somewhat different regularities of the distribution of radionuclides, In conifers, including pine, the specific activity of fine roots (<3 mm) was close to the specific activity of small branches, and the specific activity of coarse roots (3-10 mm) was close to the activity of large branches. For broadleaved species, such as birch, the activity of fine roots exceeded the activity in all the aboveground organs, and the specific activity of coarse roots was close to that in small branches. More detailed studies were performed for oak and mountain ash trees. They showed that the specific activity of fine roots (<3 mm) is close to that of the small branches. The ratios of the specific activities of the coarse roots to the specific activities in different aboveground organs may differ in dependence on the species composition of tree stands. In oak and birch trees, the specific activity of coarse roots is close to the specific activity of small branches; in mountain ash, it is closer to the specific activity of small branches.
[Distribution of 137Cs, 90Sr and their chemical analogues in the components of an above-ground part of a pine in a quasi-equilibrium condition].

PubMed

Mamikhin, S V; Manakhov, D V; Shcheglov, A I

2014-01-01

The additional study of the distribution of radioactive isotopes of caesium and strontium and their chemical analogues in the above-ground components of pine in the remote from the accident period was carried out. The results of the research confirmed the existence of analogy in the distribution of these elements on the components of this type of wood vegetation in the quasi-equilibrium (relatively radionuclides) condition. Also shown is the selective possibility of using the data on the ash content of the components of forest stands of pine and oak as an information analogue.
Necromass production: studies in undisturbed and logged Amazon Forests

Treesearch

MICHAEL PALACE; MICHAEL KELLER; HUDSON SILVA

2008-01-01

Necromass stocks account for up to 20% of carbon stored in tropical forests and have been estimated to be 14â19% of the annual aboveground carbon flux. Both stocks and fluxes of necromass are infrequently measured. In this study, we directly measured the production of fallen coarse necromass (>2 cm diameter) during 4.5 years using repeated surveys in undisturbed...
Fiberboards from loblolly pine refiner groundwood: effects of gross wood characteristics and board density

Treesearch

Charles W. McMillin

1968-01-01

Boards for insulation and and structural uses are being manufactured in increasing quantities. The coarse fiber required for these products can be disk-refined from untreated wood chips. Since such fiber is produced in essentially one mechanical operation, continuous control is required of the raw material as well as the refining process.

Disturbance and diversity of wood-inhabiting fungi: effects of canopy gaps and downed woody debris

Treesearch

Nicholas J. Brazee; Daniel L. Lindner; Anthony W. D' Amato; Shawn Fraver; Jodi A. Forrester; David J. Mladenoff

2014-01-01

Experimental canopy gap formation and additions of coarse woody debris (CWD) are techniques intended to mimic the disturbance regime and accelerate the development of northern hardwood forests. The effects of these techniques on biodiversity and ecosystem functioning were investigated by surveying the abundance and diversity of wood-inhabiting fungi in six treatments...
Assessing the potential for biomass energy development in South Carolina

Treesearch

Roger C. Conner; Tim O. Adams; Tony G. Johnson

2009-01-01

An assessment of the potential for developing a sustainable biomass energy industry in South Carolina was conducted. Biomass as defined by Forest Inventory and Analysis is the aboveground dry weight of wood in the bole and limbs of live trees â¥1-inch diameter at breast height, and excludes tree foliage, seedlings, and understory...
COMBINING LIDAR ESTIMATES OF BIOMASS AND LANDSAT ESTIMATES OF STAND AGE FOR SPATIALLY EXTENSIVE VALIDATION OF MODELED FOREST PRODUCTIVITY. (R828309)

EPA Science Inventory

Extensive estimates of forest productivity are required to understand the
relationships between shifting land use, changing climate and carbon storage
and fluxes. Aboveground net primary production of wood (NPP_Aw) is a major component
of total NPP and...
Does nitrogen and sulfur deposition affect forest productivity?

Treesearch

Brittany A. Johnson; Kathryn B. Piatek; Mary Beth Adams; John R. Brooks

2010-01-01

We studied the effects of atmospheric nitrogen and sulfur deposition on forest productivity in a 10-year-old, aggrading forest stand at the Fernow Experimental Forest in Tucker County, WV. Forest productivity was expressed as total aboveground wood biomass, which included stem and branch weight of standing live trees. Ten years after stand regeneration and treatment...
Above-ground carbon storage, downed wood, and understory plant species richness after thinning in western Oregon

Treesearch

Julia I. Burton; Adrian Ares; Sara E. Mulford; Deanna H. Olson; Klaus J. Puettmann

2013-01-01

Concerns about climate change have generated worldwide interest in managing forests for the uptake and storage of carbon (C). Simultaneously, preserving and enhancing structural, functional, and species diversity in forests remains an important objective. Therefore, understanding tradeoffs and synergies among C storage and sequestration and diversity in managed forests...
Where did the US forest biomass/carbon go?

Treesearch

Christopher William Woodall

2012-01-01

In Apr. 2012, with the submission of the 1990-2010 US Greenhouse Gas (GHG) Inventory to the United Nations Framework Convention on Climate Change (UNFCCC), the official estimates of aboveground live tree carbon stocks within managed forests of the United States will drop by approximately 14%, compared with last year's inventory. It does not stop there, dead wood...
Drivers of aboveground wood production in a lowland tropical forest of West Africa: teasing apart the roles of tree density, tree diversity, soil phosphorus, and historical logging.

PubMed

Jucker, Tommaso; Sanchez, Aida Cuni; Lindsell, Jeremy A; Allen, Harriet D; Amable, Gabriel S; Coomes, David A

2016-06-01

Tropical forests currently play a key role in regulating the terrestrial carbon cycle and abating climate change by storing carbon in wood. However, there remains considerable uncertainty as to whether tropical forests will continue to act as carbon sinks in the face of increased pressure from expanding human activities. Consequently, understanding what drives productivity in tropical forests is critical. We used permanent forest plot data from the Gola Rainforest National Park (Sierra Leone) - one of the largest tracts of intact tropical moist forest in West Africa - to explore how (1) stand basal area and tree diversity, (2) past disturbance associated with past logging, and (3) underlying soil nutrient gradients interact to determine rates of aboveground wood production (AWP). We started by statistically modeling the diameter growth of individual trees and used these models to estimate AWP for 142 permanent forest plots. We then used structural equation modeling to explore the direct and indirect pathways which shape rates of AWP. Across the plot network, stand basal area emerged as the strongest determinant of AWP, with densely packed stands exhibiting the fastest rates of AWP. In addition to stand packing density, both tree diversity and soil phosphorus content were also positively related to productivity. By contrast, historical logging activities negatively impacted AWP through the removal of large trees, which contributed disproportionately to productivity. Understanding what determines variation in wood production across tropical forest landscapes requires accounting for multiple interacting drivers - with stand structure, tree diversity, and soil nutrients all playing a key role. Importantly, our results also indicate that logging activities can have a long-lasting impact on a forest's ability to sequester and store carbon, emphasizing the importance of safeguarding old-growth tropical forests.
Coherence between woody carbon uptake and net ecosystem productivity at five eddy-covariance sites

NASA Astrophysics Data System (ADS)

Babst, F.; Bouriaud, O.; Papale, D.; Gielen, B.; Janssens, I.; Nikinmaa, E.; Ibrom, A.; Wu, J.; Bernhofer, C.; Koestner, B.; Gruenwald, T.; Seufert, G.; Ciais, P.; Frank, D. C.

2013-12-01

Forest growth ranks amongst the most important processes that determine the carbon balance of terrestrial ecosystems. Quantifications of forest carbon cycling can be made e.g. using biometric and eddy-covariance (EC) techniques. Both offer different perspectives on carbon uptake and attempts to combine them have been inconsistent and variably successful in the past. This contributes to persistent uncertainties regarding carbon allocation in forest ecosystems and complicates precise vegetation model parameterization. Aiming to reconcile assessments of carbon cycling from biometric and EC techniques, we measured radial tree growth and wood density at five long-term EC stations across Europe. The resulting records were used to calculate annual carbon uptake during above-ground wood formation and compared to monthly and seasonal CO2-flux measurements. Efforts were made to identify i) the time periods when EC and tree-ring data correspond best in different parts of Europe and ii) the fraction of eddy-fluxes which is associated with changes in above-ground woody carbon stocks. Biometric measurements and net ecosystem productivity (NEP) proved largely compatible at seasonal time scales while relationships with gross primary productivity (GPP) were often weaker. Results suggest a partitioning of sequestered carbon mainly used for volume increase (January-June) and a combination of cell-wall thickening and storage (July-September). The inter-annual variability in above-ground woody carbon uptake was significantly linked with absolute productivity ranging between 69-366 g C m-2 y-1 at boreal and temperate sites, thereby accounting for 10-25% of GPP, 15-32% of TER, and 25-80% of NEP. These findings from sites representing the major European climate zones and tree species contribute to improved quantification of above-ground carbon allocation in forests. Furthermore, they refine knowledge on processes driving ecosystem productivity important for e.g. vegetation models and provide an enhanced framework for integrative studies linking tree-ring parameters with EC measurements.
Levels of platinum group elements and rare-earth elements in wild mushroom species growing in Poland.

PubMed

Mleczek, Mirosław; Niedzielski, Przemysław; Kalač, Pavel; Siwulski, Marek; Rzymski, Piotr; Gąsecka, Monika

2016-01-01

Due to limited data-describing abilities of mushrooms to accumulate platinum group elements (PGEs) and rare-earth elements (REEs), the aim of this study was to determine, by inductively coupled plasma optical emission spectrometry followed by microwave-assisted sample digestion by nitric acid, the content of these elements in 20 mushroom species (10 above ground and 10 growing on wood), mostly edible, collected near a busy trunk road. The highest content of PGEs in above-ground mushroom species was observed in Lepista gilva and Suillus bovinus fruit bodies (0.38 ± 0.05 and 0.37 ± 0.03 mg kg(-1) DW, respectively), while in mushrooms growing on wood, the highest content was observed in Pleurotus ostreatus (0.35 ± 0.04 mg kg(-1) DW). The mean content of PGEs for both these groups was 0.23 ± 0.08 and 0.26 ± 0.07 mg kg(-1) DW, respectively. The highest content of REEs in Suillus luteus and Tricholoma equestra was 5.03 ± 0.50 and 2.18 ± 0.56 mg kg(-1) DW, respectively, but within mushrooms growing on wood in Ganoderma applanatum fruiting bodies it was 4.19 ± 0.78 mg kg(-1) DW. Mean contents of REEs were 1.39 ± 1.21 and 1.61 ± 0.97 mg kg(-1) DW in above-ground species and species growing on wood, respectively. Generally, the group of mushroom species growing on wood was capable of slightly higher accumulation of both REEs and PGEs. No limits have been established for both the groups until now.
Does clear-cut harvesting accelerate initial wood decomposition? A five-year study with standard wood material

Treesearch

L. Finer; M. Jurgensen; M. Palviainen; S. Piirainen; Deborah Page-Dumroese

2016-01-01

Coarse woody debris (CWD) serves a variety of ecological functions in forests, and the understanding of its decomposition is needed for estimating changes in CWD-dependent forest biodiversity, and for the quantification of forest ecosystem carbon and nutrient pools and fluxes. Boreal forests are often intensively managed, so information is needed on the effects of...
Critical length sampling: a method to estimate the volume of downed coarse woody debris

Treesearch

G& #246; ran St& #229; hl; Jeffrey H. Gove; Michael S. Williams; Mark J. Ducey

2010-01-01

In this paper, critical length sampling for estimating the volume of downed coarse woody debris is presented. Using this method, the volume of downed wood in a stand can be estimated by summing the critical lengths of down logs included in a sample obtained using a relascope or wedge prism; typically, the instrument should be tilted 90° from its usual...
Spatio-temporal variation of coarse woody debris input in woodland key habitats in central Sweden

Treesearch

Mari Jonsson; Shawn Fraver; Bengt Gunnar. Jonsson

2011-01-01

The persistence of many saproxylic (wood-living) species depends on a readily available supply of coarse woody debris (CWD). Most studies of CWD inputs address stand-level patterns, despite the fact that many saproxylic species depend on landscape-level supplies of CWD. In the present study we used dated CWD inputs (tree mortality events) at each of 14 Norway spruce (...
Biomass partitioning in red pine (Pinus resinosa) along a chronosequence in the Upper Peninsula of Michigan

Treesearch

J.S. King; C.P. Giardina; K.S. Pregitzer; A.L. Friend

2007-01-01

Carbon (C) allocation to the perennial coarse-root system of trees contributes to ecosystem C sequestration through formation of long-lived live wood biomass and, following senescence, by providing a large source of nutrient-poor detrital C. Our understanding of the controls on C allocation to coarse-root growth is rudimentary, but it has important implications for...
Species composition and forest structure explain the temperature sensitivity patterns of productivity in temperate forests

NASA Astrophysics Data System (ADS)

Bohn, Friedrich J.; May, Felix; Huth, Andreas

2018-03-01

Rising temperatures due to climate change influence the wood production of forests. Observations show that some temperate forests increase their productivity, whereas others reduce their productivity. This study focuses on how species composition and forest structure properties influence the temperature sensitivity of aboveground wood production (AWP). It further investigates which forests will increase their productivity the most with rising temperatures. We described forest structure by leaf area index, forest height and tree height heterogeneity. Species composition was described by a functional diversity index (Rao's Q) and a species distribution index (ΩAWP). ΩAWP quantified how well species are distributed over the different forest layers with regard to AWP. We analysed 370 170 forest stands generated with a forest gap model. These forest stands covered a wide range of possible forest types. For each stand, we estimated annual aboveground wood production and performed a climate sensitivity analysis based on 320 different climate time series (of 1-year length). The scenarios differed in mean annual temperature and annual temperature amplitude. Temperature sensitivity of wood production was quantified as the relative change in productivity resulting from a 1 °C rise in mean annual temperature or annual temperature amplitude. Increasing ΩAWP positively influenced both temperature sensitivity indices of forest, whereas forest height showed a bell-shaped relationship with both indices. Further, we found forests in each successional stage that are positively affected by temperature rise. For such forests, large ΩAWP values were important. In the case of young forests, low functional diversity and small tree height heterogeneity were associated with a positive effect of temperature on wood production. During later successional stages, higher species diversity and larger tree height heterogeneity were an advantage. To achieve such a development, one could plant below the closed canopy of even-aged, pioneer trees a climax-species-rich understorey that will build the canopy of the mature forest. This study highlights that forest structure and species composition are both relevant for understanding the temperature sensitivity of wood production.
Wood phenology, not carbon input, controls the interannual variability of wood growth in a temperate oak forest.

PubMed

Delpierre, Nicolas; Berveiller, Daniel; Granda, Elena; Dufrêne, Eric

2016-04-01

Although the analysis of flux data has increased our understanding of the interannual variability of carbon inputs into forest ecosystems, we still know little about the determinants of wood growth. Here, we aimed to identify which drivers control the interannual variability of wood growth in a mesic temperate deciduous forest. We analysed a 9-yr time series of carbon fluxes and aboveground wood growth (AWG), reconstructed at a weekly time-scale through the combination of dendrometer and wood density data. Carbon inputs and AWG anomalies appeared to be uncorrelated from the seasonal to interannual scales. More than 90% of the interannual variability of AWG was explained by a combination of the growth intensity during a first 'critical period' of the wood growing season, occurring close to the seasonal maximum, and the timing of the first summer growth halt. Both atmospheric and soil water stress exerted a strong control on the interannual variability of AWG at the study site, despite its mesic conditions, whilst not affecting carbon inputs. Carbon sink activity, not carbon inputs, determined the interannual variations in wood growth at the study site. Our results provide a functional understanding of the dependence of radial growth on precipitation observed in dendrological studies. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.
Evaluation of total aboveground biomass and total merchantable biomass in Missouri

Treesearch

Michael E. Goerndt; David R. Larsen; Charles D. Keating

2014-01-01

In recent years, the state of Missouri has been converting to biomass weight rather than volume as the standard measurement of wood for buying and selling sawtimber. Therefore, there is a need to identify accurate and precise methods of estimating whole tree biomass and merchantable biomass of harvested trees as well as total standing biomass of live timber for...
Summary of nutrient and biomass data from two aspen sites in western United States

Treesearch

Robert S. Johnston; Dale L. Bartos

1977-01-01

Summary tables are presented for aboveground biomass and nutrient concentrations for 20 aspen trees (Populus tremuloides Michx.) that were sampled at two study sites in Utah and Wyoming. Trees were divided into seven components - leaves, current twigs, old twigs, deadwood (branches), branches, bark, and bole wood. Samples from each component were analyzed for nitrogen...
An experimental test of the causes of forest growth decline with stand age.

Treesearch

Michael G. Ryan; Dan Binkley; James H. Fownes; Christian Giardina; Randy S. Senock

2004-01-01

The decline in aboveground wood production after canopy closure in even-aged forest stands is a common pattern in forests, but clear evidence for the mechanism causing the decline is lacking. The problem is fundamental to forest biology, commercial forestry (the decline sets the rotation age), and to carbon storage in forests. We tested three hypotheses...
Multielemental analysis of 20 mushroom species growing near a heavily trafficked road in Poland.

PubMed

Mleczek, M; Niedzielski, P; Kalač, P; Budka, A; Siwulski, M; Gąsecka, M; Rzymski, P; Magdziak, Z; Sobieralski, K

2016-08-01

The aim of this work was to compare 10 mostly edible aboveground and 10 wood-growing mushroom species collected near a heavily trafficked road (approximately 28,000 vehicles per 24 h) in Poland with regard to their capacity to accumulate 26 trace elements (Ag, Al, As, Au, B, Ba, Bi, Cd, Co, Cr, Cu, Fe, Ga, Ge, In, Li, Mn, Ni, Pb, Re, Sb, Se, Sr, Te, Tl, and Zn) in their fruit bodies in order to illustrate mushroom diversity in element accumulation. All analyses were performed using an inductively coupled plasma optical emission spectrometry (ICP-OES) spectrometer in synchronous dual view mode. The aboveground species had significantly higher levels of 12 elements, including Ag, As, Pb, and Se, compared to the wood-growing species. An opposite relationship was observed only for Au, Ba, and Sr. The results of principal component analysis (PCA) and hierarchical cluster analysis (HCA) implied some new relationships among the analyzed species and elements. Of the analyzed mushroom species, lead content in Macrolepiota procera would seem to pose a health risk; however, at present knowledge regarding lead bioaccessibility from mushrooms is quite limited.
Spatial and temporal patterns of beetles associated with coarse woody debris in managed bottomland hardwood forests.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ulyshen, M., D.; Hanula, J., L.; Horn, S.

2004-05-13

For. Ecol. and Mgt. 199:259-272. Malaise traps were used to sample beetles in artificial canopy gaps of different size (0.13 ha, 0.26 ha, and0.50 ha) and age in a South Carolina bottomland hardwood forest. Traps were placed at the center, edge, and in the surrounding forest of each gap. Young gaps (ý 1 year) had large amounts of coarse woody debris compared to the surrounding forest, while older gaps (ý 6 years) had virtually none. The total abundance and diversity of wood-dwelling beetles (Buprestidae, Cerambycidae, Brentidae, Bostrichidae, and Curculionidae (Scolytinae and Platypodinae)) was higher in the center of young gapsmore » than in the center of old gaps. The abundance was higher in the center of young gaps than in the surrounding forest, while the forest surrounding old gaps and the edge of old gaps had a higher abundance and diversity of wood-dwelling beetles than did the center of old gaps. There was no difference in wood-dwelling beetle abundance between gaps of different size, but diversity was lower in 0.13 ha old gaps than in 0.26 ha or 0.50 ha old gaps. We suspect that gap size has more of an effect on woodborer abundance than indicated here because malaise traps sample a limited area. The predaceous beetle family Cleridae showed a very similar trend to that of the woodborers. Coarse woody debris is an important resource for many organisms, and our results lend further support to forest management practices that preserve coarse woody debris created during timber removal.« less

Hypholoma lateritium isolated from coarse woody debris, the forest floor, and mineral soil in a deciduous forest in New Hampshire

Treesearch

Therese A. Thompson; R. Greg Thorn; Kevin T. Smith

2012-01-01

Fungi in the Agaricomycetes (Basidiomycota) are the primary decomposers in temperate forests of dead wood on and in the forest soil. Through the use of isolation techniques selective for saprotrophic Agaricomycetes, a variety of wood decay fungi were isolated from a northern hardwood stand in the Bartlett Experimental Forest, New Hampshire, USA. In particular,
Role of soil texture, clay mineralogy, location, and temperature in coarse wood decomposition - a mesocosm experiment

Treesearch

Cinzia Fissore; Martin F. Jurgensen; James Pickens; Chris Miller; Deborah Page-Dumroese; Christian P. Giardina

2016-01-01

Of all the major pools of terrestrial carbon (C), the dynamics of coarse woody debris (CWD) are the least understood. In contrast to soils and living vegetation, the study of CWD has rarely relied on ex situ methods for elaborating controls on decomposition rates. In this study, we report on a mesocosm incubation experiment examining how clay amount (8%, 16%,...
Multiple metrics of diversity have different effects on temperate forest functioning over succession.

PubMed

Yuan, Zuoqiang; Wang, Shaopeng; Gazol, Antonio; Mellard, Jarad; Lin, Fei; Ye, Ji; Hao, Zhanqing; Wang, Xugao; Loreau, Michel

2016-12-01

Biodiversity can be measured by taxonomic, phylogenetic, and functional diversity. How ecosystem functioning depends on these measures of diversity can vary from site to site and depends on successional stage. Here, we measured taxonomic, phylogenetic, and functional diversity, and examined their relationship with biomass in two successional stages of the broad-leaved Korean pine forest in northeastern China. Functional diversity was calculated from six plant traits, and aboveground biomass (AGB) and coarse woody productivity (CWP) were estimated using data from three forest censuses (10 years) in two large fully mapped forest plots (25 and 5 ha). 11 of the 12 regressions between biomass variables (AGB and CWP) and indices of diversity showed significant positive relationships, especially those with phylogenetic diversity. The mean tree diversity-biomass regressions increased from 0.11 in secondary forest to 0.31 in old-growth forest, implying a stronger biodiversity effect in more mature forest. Multi-model selection results showed that models including species richness, phylogenetic diversity, and single functional traits explained more variation in forest biomass than other candidate models. The models with a single functional trait, i.e., leaf area in secondary forest and wood density in mature forest, provided better explanations for forest biomass than models that combined all six functional traits. This finding may reflect different strategies in growth and resource acquisition in secondary and old-growth forests.
DOE Office of Scientific and Technical Information (OSTI.GOV)

Horn, Scott; Hanula, James, L.

Abstract This study determined if short-term removal of coarse woody debris would reduce prey available to red-cockaded woodpeckers (Picoides borealis Vieillot) and other bark-foraging birds at the Savannah River Site in Aiken and Barnwell counties, SC. All coarse woody debris was removed from four 9-ha plots of mature loblolly pine (Pinus taeda L.) in 1997 and again in 1998. We sampled arthropods in coarse woody debris removal and control stands using crawl traps that captured arthropods crawling up tree boles, burlap bands wrapped around trees, and cardboard panels placed on the ground. We captured 27 orders and 172 families ofmore » arthropods in crawl traps whereas 20 arthropod orders were observed under burlap bands and cardboard panels. The most abundant insects collected from crawl traps were aphids (Homoptera: Aphididae) and ants (Hymenoptera: Forrnicidae). The greatest biomass was in the wood cockroaches (Blattaria: Blattellidae), caterpillars (Lepidoptera) in the Family Noctuidae, and adult weevils (Coleoptera: Curculionidae). The most common group observed underneath cardboard panels was lsoptera (termites), and the most common taxon under burlap bands was wood cockroaches. Overall, arthropod abundance and biomass captured in crawl traps was similar in control and removal plots. In contrast, we observed more arthropods under burlap bands (mean & SE; 3,021.5 k 348.6, P= 0.03) and cardboard panels (3,537.25 k 432.4, P= 0.04) in plots with coarse woody debris compared with burlap bands (2325 + 171.3) and cardboard panels (2439.75 + 288.9) in plots where coarse woody debris was removed. Regression analyses showed that abundance beneath cardboard panels was positively correlated with abundance beneath burlap bands demonstrating the link between abundance on the ground with that on trees. Our results demonstrate that short-term removal of coarse woody debris from pine forests reduced overall arthropod availability to bark-foraging birds.« less
The effects of a western spruce budworm outbreak on the dead wood component in relation to ownership in forests of eastern Oregon

Treesearch

David Azuma

2010-01-01

Forest Inventory and Analysis data were used to investigate the effects of a severe western spruce budworm outbreak on the dead wood component of forests in 11 counties of eastern Oregon for two time periods. The ownership and the level of damage (as assessed by aerial surveys) affected the resulting down woody material and standing dead trees. The pattern of coarse...
Efficacy of generic allometric equations for estimating biomass: a test in Japanese natural forests.

PubMed

Ishihara, Masae I; Utsugi, Hajime; Tanouchi, Hiroyuki; Aiba, Masahiro; Kurokawa, Hiroko; Onoda, Yusuke; Nagano, Masahiro; Umehara, Toru; Ando, Makoto; Miyata, Rie; Hiura, Tsutom

2015-07-01

Accurate estimation of tree and forest biomass is key to evaluating forest ecosystem functions and the global carbon cycle. Allometric equations that estimate tree biomass from a set of predictors, such as stem diameter and tree height, are commonly used. Most allometric equations are site specific, usually developed from a small number of trees harvested in a small area, and are either species specific or ignore interspecific differences in allometry. Due to lack of site-specific allometries, local equations are often applied to sites for which they were not originally developed (foreign sites), sometimes leading to large errors in biomass estimates. In this study, we developed generic allometric equations for aboveground biomass and component (stem, branch, leaf, and root) biomass using large, compiled data sets of 1203 harvested trees belonging to 102 species (60 deciduous angiosperm, 32 evergreen angiosperm, and 10 evergreen gymnosperm species) from 70 boreal, temperate, and subtropical natural forests in Japan. The best generic equations provided better biomass estimates than did local equations that were applied to foreign sites. The best generic equations included explanatory variables that represent interspecific differences in allometry in addition to stem diameter, reducing error by 4-12% compared to the generic equations that did not include the interspecific difference. Different explanatory variables were selected for different components. For aboveground and stem biomass, the best generic equations had species-specific wood specific gravity as an explanatory variable. For branch, leaf, and root biomass, the best equations had functional types (deciduous angiosperm, evergreen angiosperm, and evergreen gymnosperm) instead of functional traits (wood specific gravity or leaf mass per area), suggesting importance of other traits in addition to these traits, such as canopy and root architecture. Inclusion of tree height in addition to stem diameter improved the performance of the generic equation only for stem biomass and had no apparent effect on aboveground, branch, leaf, and root biomass at the site level. The development of a generic allometric equation taking account of interspecific differences is an effective approach for accurately estimating aboveground and component biomass in boreal, temperate, and subtropical natural forests.
A wood density and aboveground biomass variability assessment using pre-felling inventory data in Costa Rica.

PubMed

Svob, Sienna; Arroyo-Mora, J Pablo; Kalacska, Margaret

2014-12-01

The high spatio-temporal variability of aboveground biomass (AGB) in tropical forests is a large source of uncertainty in forest carbon stock estimation. Due to their spatial distribution and sampling intensity, pre-felling inventories are a potential source of ground level data that could help reduce this uncertainty at larger spatial scales. Further, exploring the factors known to influence tropical forest biomass, such as wood density and large tree density, will improve our knowledge of biomass distribution across tropical regions. Here, we evaluate (1) the variability of wood density and (2) the variability of AGB across five ecosystems of Costa Rica. Using forest management (pre-felling) inventories we found that, of the regions studied, Huetar Norte had the highest mean wood density of trees with a diameter at breast height (DBH) greater than or equal to 30 cm, 0.623 ± 0.182 g cm -3 (mean ± standard deviation). Although the greatest wood density was observed in Huetar Norte, the highest mean estimated AGB (EAGB) of trees with a DBH greater than or equal to 30 cm was observed in Osa peninsula (173.47 ± 60.23 Mg ha -1 ). The density of large trees explained approximately 50% of EAGB variability across the five ecosystems studied. Comparing our study's EAGB to published estimates reveals that, in the regions of Costa Rica where AGB has been previously sampled, our forest management data produced similar values. This study presents the most spatially rich analysis of ground level AGB data in Costa Rica to date. Using forest management data, we found that EAGB within and among five Costa Rican ecosystems is highly variable. Combining commercial logging inventories with ecological plots will provide a more representative ground level dataset for the calibration of the models and remotely sensed data used to EAGB at regional and national scales. Additionally, because the non-protected areas of the tropics offer the greatest opportunity to reduce rates of deforestation and forest degradation, logging inventories offer a promising source of data to support mechanisms such as the United Nations REDD + (Reducing Emissions from Tropical Deforestation and Degradation) program.
Comparative analysis of spectral unmixing and neural networks for estimating small diameter tree above-ground biomass in the State of Mississippi

Treesearch

Moham P. Tiruveedhula; Joseph Fan; Ravi R. Sadasivuni; Surya S. Durbha; David L. Evans

2010-01-01

The accumulation of small diameter trees (SDTs) is becoming a nationwide concern. Forest management practices such as fire suppression and selective cutting of high grade timber have contributed to an overabundance of SDTs in many areas. Alternative value-added utilization of SDTs (for composite wood products and biofuels) has prompted the need to estimate their...
A 6 year longitudinal study of post-fire woody carbon dynamics in California's forests

Treesearch

Bianca N.I. Eskelson; Vicente J. Monleon; Jeremy S. Fried

2016-01-01

We examined the dynamics of aboveground forest woody carbon pools â live trees, standing dead trees, and down woodâduring the first 6 years following wildfire across a wide range of conditions, which are characteristic of California forest fires. From repeated measurements of the same plots, we estimated change in woody carbon pools as a function of crown fire severity...
Dynamics of Aboveground Phytomass of the Circumpolar Arctic Tundra During the Past Three Decades

NASA Technical Reports Server (NTRS)

Epstein, Howard E.; Raynolds, Martha K.; Walker, Donald A.; Bhatt, Uma S.; Tucker, Compton J.; Pinzon, Jorge E.

2012-01-01

Numerous studies have evaluated the dynamics of Arctic tundra vegetation throughout the past few decades, using remotely sensed proxies of vegetation, such as the normalized difference vegetation index (NDVI). While extremely useful, these coarse-scale satellite-derived measurements give us minimal information with regard to how these changes are being expressed on the ground, in terms of tundra structure and function. In this analysis, we used a strong regression model between NDVI and aboveground tundra phytomass, developed from extensive field-harvested measurements of vegetation biomass, to estimate the biomass dynamics of the circumpolar Arctic tundra over the period of continuous satellite records (1982-2010). We found that the southernmost tundra subzones (C-E) dominate the increases in biomass, ranging from 20 to 26%, although there was a high degree of heterogeneity across regions, floristic provinces, and vegetation types. The estimated increase in carbon of the aboveground live vegetation of 0.40 Pg C over the past three decades is substantial, although quite small relative to anthropogenic C emissions. However, a 19.8% average increase in aboveground biomass has major implications for nearly all aspects of tundra ecosystems including hydrology, active layer depths, permafrost regimes, wildlife and human use of Arctic landscapes. While spatially extensive on-the-ground measurements of tundra biomass were conducted in the development of this analysis, validation is still impossible without more repeated, long-term monitoring of Arctic tundra biomass in the field.
Allometric Equations for Aboveground and Belowground Biomass Estimations in an Evergreen Forest in Vietnam.

PubMed

Nam, Vu Thanh; van Kuijk, Marijke; Anten, Niels P R

2016-01-01

Allometric regression models are widely used to estimate tropical forest biomass, but balancing model accuracy with efficiency of implementation remains a major challenge. In addition, while numerous models exist for aboveground mass, very few exist for roots. We developed allometric equations for aboveground biomass (AGB) and root biomass (RB) based on 300 (of 45 species) and 40 (of 25 species) sample trees respectively, in an evergreen forest in Vietnam. The biomass estimations from these local models were compared to regional and pan-tropical models. For AGB we also compared local models that distinguish functional types to an aggregated model, to assess the degree of specificity needed in local models. Besides diameter at breast height (DBH) and tree height (H), wood density (WD) was found to be an important parameter in AGB models. Existing pan-tropical models resulted in up to 27% higher estimates of AGB, and overestimated RB by nearly 150%, indicating the greater accuracy of local models at the plot level. Our functional group aggregated local model which combined data for all species, was as accurate in estimating AGB as functional type specific models, indicating that a local aggregated model is the best choice for predicting plot level AGB in tropical forests. Finally our study presents the first allometric biomass models for aboveground and root biomass in forests in Vietnam.
Allometric Equations for Aboveground and Belowground Biomass Estimations in an Evergreen Forest in Vietnam

PubMed Central

Nam, Vu Thanh; van Kuijk, Marijke; Anten, Niels P. R.

2016-01-01

Allometric regression models are widely used to estimate tropical forest biomass, but balancing model accuracy with efficiency of implementation remains a major challenge. In addition, while numerous models exist for aboveground mass, very few exist for roots. We developed allometric equations for aboveground biomass (AGB) and root biomass (RB) based on 300 (of 45 species) and 40 (of 25 species) sample trees respectively, in an evergreen forest in Vietnam. The biomass estimations from these local models were compared to regional and pan-tropical models. For AGB we also compared local models that distinguish functional types to an aggregated model, to assess the degree of specificity needed in local models. Besides diameter at breast height (DBH) and tree height (H), wood density (WD) was found to be an important parameter in AGB models. Existing pan-tropical models resulted in up to 27% higher estimates of AGB, and overestimated RB by nearly 150%, indicating the greater accuracy of local models at the plot level. Our functional group aggregated local model which combined data for all species, was as accurate in estimating AGB as functional type specific models, indicating that a local aggregated model is the best choice for predicting plot level AGB in tropical forests. Finally our study presents the first allometric biomass models for aboveground and root biomass in forests in Vietnam. PMID:27309718
Underground riparian wood: Reconstructing the processes influencing buried stem and coarse root structures of Black Poplar (Populus nigra L.)

NASA Astrophysics Data System (ADS)

Holloway, James V.; Rillig, Matthias C.; Gurnell, Angela M.

2017-02-01

Following analysis of morphological (including dendrochronological and sedimentological) aspects of buried stem and coarse root structures of eight mature P. nigra individuals located within two sites along the middle to lower Tagliamento River, Italy (Holloway et al., 2017), this paper introduces information on the historical processes of vegetation development and river flow and links this to the form of these eight trees. Aerial images and flow time series are assembled to reconstruct the flood history, potential recruitment periods, and vegetation cover development in the vicinity of the studied trees. This information is combined with previous morphological evidence to reconstruct the development history of each tree via three-element summary diagrams showing (i) a time series of floods, aerial imagery dates, and potential recruitment periods, with colour-coded bars indicating likely key stages in the development of the tree; (ii) colour-coded overlays on an SfM photogrammetric model of each tree; and (iii) colour-coded text boxes providing explanatory annotations. The combined morphology-process analysis reveals complex three-dimensional underground structures, incorporating buried stems, shoots, and adventitious roots that are sometimes joined by grafting, linking the standing tree with the buried gravel surface on which it was recruited. Analysis of process data provides a firm basis for identifying and dating influential flow disturbance events and recruitment windows and shows that a relatively small number of flood events have significantly impacted the studied trees, which are mainly but not exclusively the largest floods in the record. Nevertheless, we stress that all suggested dates are best estimates in the light of the combined evidence. There is undoubted potential for building different interpretations of belowground woody structure development in light of such evidence, but we feel that the form and timing of the developmental trajectories we have proposed are reasonable and give balanced insights into the many possible ways in which this hidden component of riparian trees may develop. Our results are relevant to river research and management issues concerning riparian woodland, fluvial wood dynamics, and wood budgets, as they indicate (i) a large hidden volume of wood that is often ignored; (ii) complex, deep, coarse anchorage structures that have relevance for rates of fluvial wood recruitment associated with lateral bank erosion/stability or wind throw; and (iii) a wood element that may significantly affect wood transport and retention within fluvial systems.
Specific gravity of woody tissue from lowland Neotropical plants: differences among forest types.

PubMed

Casas, Luisa Fernanda; Aldana, Ana María; Henao-Diaz, Francisco; Villanueva, Boris; Stevenson, Pablo R

2017-05-01

Wood density, or more precisely, wood specific gravity, is an important parameter when estimating aboveground biomass, which has become a central tool for the management and conservation of forests around the world. When using biomass allometric equations for tropical forests, researchers are often required to assume phylogenetic trait conservatism, which allows us to assign genus- and family-level wood specific gravity mean values, to many woody species. The lack of information on this trait for many Neotropical plant species has led to an imprecise estimation of the biomass stored in Neotropical forests. The data presented here has information of woody tissue specific gravity from 2,602 individual stems for 386 species, including trees, lianas, and hemi-epiphytes of lowland tropical forests in Colombia. This data set was produced by us collecting wood cores from woody species in five localities in the Orinoco and Magdalena Basins in Colombia. We found lower mean specific gravity values in várzea than in terra firme and igapó. © 2017 The Authors. Ecology, published by Wiley Periodicals, Inc., on behalf of the Ecological Society of America.
Abiotic and biotic determinants of coarse woody productivity in temperate mixed forests.

PubMed

Yuan, Zuoqiang; Ali, Arshad; Wang, Shaopeng; Gazol, Antonio; Freckleton, Robert; Wang, Xugao; Lin, Fei; Ye, Ji; Zhou, Li; Hao, Zhanqing; Loreau, Michel

2018-07-15

Forests play an important role in regulating the global carbon cycle. Yet, how abiotic (i.e. soil nutrients) and biotic (i.e. tree diversity, stand structure and initial biomass) factors simultaneously contribute to aboveground biomass (coarse woody) productivity, and how the relative importance of these factors changes over succession remain poorly studied. Coarse woody productivity (CWP) was estimated as the annual aboveground biomass gain of stems using 10-year census data in old growth and secondary forests (25-ha and 4.8-ha, respectively) in northeast China. Boosted regression tree (BRT) model was used to evaluate the relative contribution of multiple metrics of tree diversity (taxonomic, functional and phylogenetic diversity and trait composition as well as stand structure attributes), stand initial biomass and soil nutrients on productivity in the studied forests. Our results showed that community-weighted mean of leaf phosphorus content, initial stand biomass and soil nutrients were the three most important individual predictors for CWP in secondary forest. Instead, initial stand biomass, rather than diversity and functional trait composition (vegetation quality) was the most parsimonious predictor of CWP in old growth forest. By comparing the results from secondary and old growth forest, the summed relative contribution of trait composition and soil nutrients on productivity decreased as those of diversity indices and initial biomass increased, suggesting the stronger effect of diversity and vegetation quantity over time. Vegetation quantity, rather than diversity and soil nutrients, is the main driver of forest productivity in temperate mixed forest. Our results imply that diversity effect for productivity in natural forests may not be so important as often suggested, at least not during the later stage of forest succession. This finding suggests that as a change of the importance of different divers of productivity, the environmentally driven filtering decreases and competitively driven niche differentiation increases with forest succession. Copyright © 2018 Elsevier B.V. All rights reserved.
Contrasting seasonal overlaps between primary and secondary growth are linked to wood anatomy in Mediterranean sub-shrubs.

PubMed

Camarero, J J; Palacio, S; Montserrat-Martí, G

2013-09-01

Whole-plant approaches allow quantification of the temporal overlap between primary and secondary growth. If the amount of time available to grow is short, there may be a high temporal overlap between shoot growth and wood formation. We hypothesise that such overlap depends on the duration of the growing season and relates to wood anatomy. We evaluated wood anatomy, shoot longitudinal and radial growth rates, fine root production and the concentrations of non-structural carbohydrates (NSC) in the wood of six sub-shrub species growing in sites with contrasting climatic conditions (Lepidium subulatum, Linum suffruticosum, Salvia lavandulifolia, Satureja montana, Ononis fruticosa, Echinospartum horridum). Sub-shrub species living in sites with a short growing season displayed a high overlap between aboveground primary and secondary growth and formed wide vessels, whereas species from the warmest and driest sites presented the reverse characteristics. The highest overlap was linked to a rapid shoot extension and thickening through the enhanced hydraulic conductivity provided by wide vessels. The reductions in NSC concentrations when growth peaked were low or moderate, indicating that sub-shrubs accumulate NSC in excess, as do trees. The temporal overlap among primary and secondary growth in woody plants may be connected to the duration and rates of shoot and wood growth, which in turn depend on the vessel lumen area. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.
Estimates of biomass in logging residue and standing residual inventory following tree-harvest activity on timberland acres in the southern region

Treesearch

Roger C. Conner; Tony G. Johnson

2011-01-01

This report provides estimates of biomass (green tons) in logging residue and standing residual inventory on timberland acres with evidence of tree cutting. Biomass as defined by Forest Inventory and Analysis is the aboveground dry weight of wood in the bole and limbs of live trees â¥ 1-inch diameter at breast height (d.b.h.), and excludes tree foliage, seedlings, and...
Liana infestation impacts tree growth in a lowland tropical moist forest

NASA Astrophysics Data System (ADS)

van der Heijden, G. M. F.; Phillips, O. L.

2009-03-01

Stand-level estimates of the effect of lianas on tree growth in mature tropical forests are needed to evaluate the functional impact of lianas and their potential to affect the ability of tropical forests to sequester carbon, but these are currently lacking. Using data collected on tree growth rates, local growing conditions and liana competition in five permanent sampling plots in Amazonian Peru, we present the first such estimates of the effect of lianas on above-ground productivity of trees. By constructing a multi-level linear mixed effect model to predict individual tree diameter growth model using individual tree growth conditions, we were able to estimate stand-level above-ground biomass (AGB) increment in the absence of lianas. We show that lianas, mainly by competing above-ground with trees, reduce tree annual above-ground stand-level biomass by ~10%, equivalent to 0.51 Mg dry weight ha-1 yr-1 or 0.25 Mg C ha-1 yr-1. AGB increment of lianas themselves was estimated to be 0.15 Mg dry weight ha-1 yr-1 or 0.07 Mg C ha-1 yr-1, thus only compensating ~29% of the liana-induced reduction in stand-level AGB increment. Increasing liana pressure on tropical forests may therefore not only reduce their carbon storage capacity, by indirectly promoting tree species with low-density wood, but also their rate of carbon uptake, with potential consequences for the rate of increase in atmospheric carbon dioxide.
Liana infestation impacts tree growth in a lowland tropical moist forest

NASA Astrophysics Data System (ADS)

van der Heijden, G. M. F.; Phillips, O. L.

2009-10-01

Ecosystem-level estimates of the effect of lianas on tree growth in mature tropical forests are needed to evaluate the functional impact of lianas and their potential to affect the ability of tropical forests to sequester carbon, but these are currently lacking. Using data collected on tree growth rates, local growing conditions and liana competition in five permanent sampling plots in Amazonian Peru, we present the first ecosystem-level estimates of the effect of lianas on above-ground productivity of trees. By first constructing a multi-level linear mixed effect model to predict individual-tree diameter growth model using individual-tree growth conditions, we were able to then estimate stand-level above-ground biomass (AGB) increment in the absence of lianas. We show that lianas, mainly by competing above-ground with trees, reduce tree annual above-ground stand-level biomass increment by ~10%, equivalent to 0.51 Mg dry weight ha-1 yr-1 or 0.25 Mg C ha-1 yr-1. AGB increment of lianas themselves was estimated to be 0.15 Mg dry weight ha-1 yr-1 or 0.07 Mg C ha-1 yr-1, thus only compensating ~29% of the liana-induced reduction in ecosystem AGB increment. Increasing liana pressure on tropical forests will therefore not only tend to reduce their carbon storage capacity, by indirectly promoting tree species with low-density wood, but also their rate of carbon uptake, with potential consequences for the rate of increase in atmospheric carbon dioxide.
Forest management strategies for reducing carbon emissions, the French case

NASA Astrophysics Data System (ADS)

Valade, Aude; Luyssaert, Sebastiaan; Bellassen, Valentin; Vallet, Patrick; Martin, Manuel

2015-04-01

International agreements now recognize the role of forest in the mitigation of climate change through the levers of in-situ sequestration, storage in products and energy and product substitution. These three strategies of carbon management are often antagonistic and it is still not clear which strategy would have the most significant impact on atmospheric carbon concentrations. With a focus on France, this study compares several scenarios of forest management in terms of their effect on the overall carbon budget from trees to wood-products. We elaborated four scenarios of forest management that target different wood production objectives. One scenario is 'Business as usual' and reproduces the current forest management and wood production levels. Two scenarios target an increase in bioenergy wood production, with either long-term or short-term goals. One scenario aims at increasing the production of timber for construction. For this, an empirical regression model was developed building on the rich French inventory database. The model can project the current forest resource at a time horizon of 20 years for characteristic variables diameter, standing volume, above-ground biomass, stand age. A simplified life-cycle analysis provides a full carbon budget for each scenario from forest management to wood use and allows the identification of the scenario that most reduces carbon emissions.

Effect of coarse woody debris manipulation on soricid and herpetofaunal communities in upland pine stands of the southeastern coastal plain.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, Justin, Charles

2009-04-01

Abstract -The majority of studies investigating the importance of coarse woody debris (CWD) to forest- floor vertebrates have taken place in the Pacific Northwest and southern Appalachian Mountains, while comparative studies in the southeastern Coastal Plain are lacking. My study was a continuation of a long-term project investigating the importance of CWD as a habitat component for shrew and herpetofaunal communities within managed pine stands in the southeastern Coastal Plain. Results suggest that addition of CWD can increase abundance of southeastern and southern short-tailed shrews. However, downed wood does not appear to be a critical habitat component for amphibians andmore » reptiles. Rising petroleum costs and advances in wood utilization technology have resulted in an emerging biofuels market with potential to decrease CWD volumes left in forests following timber harvests. Therefore, forest managers must understand the value of CWD as an ecosystem component to maintain economically productive forests while conserving biological diversity.« less
Biomass and Nutrient Distribution in 3-Year Old Green Ash and Swamp Chestnut Oak Grown in a Minor Stream Bottom

Treesearch

Harvey E. Kennedy; Bryce E. Schlaegel

1985-01-01

After three growing seasons, green ash had produced 7,342 pounds per acre of above-ground dry matter compared to 3,572 for oak. Of the total biomass, ash had 53% in the bole (wood plus bark), 22% in old branches, 21% in leaves and 4% in new growth; oak had 50%, 21%, 24%, and 5% in the same components. These proportions changed after leaf fall. Concentrations of N, P, K...
Transplantation of subalpine wood-pasture turfs along a natural climatic gradient reveals lower resistance of unwooded pastures to climate change compared to wooded ones.

PubMed

Gavazov, Konstantin; Spiegelberger, Thomas; Buttler, Alexandre

2014-04-01

Climate change could impact strongly on cold-adapted mountain ecosystems, but little is known about its interaction with traditional land-use practices. We used an altitudinal gradient to simulate a year-round warmer and drier climate for semi-natural subalpine grasslands across a landscape of contrasting land-use management. Turf mesocosms from three pasture-woodland land-use types-unwooded pasture, sparsely wooded pasture, and densely wooded pasture-spanning a gradient from high to low management intensity were transplanted downslope to test their resistance to two intensities of climate change. We found strong overall effects of intensive (+4 K) experimental climate change (i.e., warming and reduced precipitation) on plant community structure and function, while moderate (+2 K) climate change did not substantially affect the studied land-use types, thus indicating an ecosystem response threshold to moderate climate perturbation. The individual land-use types were affected differently under the +4 K scenario, with a 60% decrease in aboveground biomass (AGB) in unwooded pasture turfs, a 40% decrease in sparsely wooded pasture turfs, and none in densely wooded ones. Similarly, unwooded pasture turfs experienced a 30% loss of species, advanced (by 30 days) phenological development, and a mid-season senescence due to drought stress, while no such effects were recorded for the other land-use types. The observed contrasting effects of climate change across the pasture-woodland landscape have important implications for future decades. The reduced impact of climate change on wooded pastures as compared to unwooded ones should promote the sustainable land use of wooded pastures by maintaining low management intensity and a sparse forest canopy, which buffer the immediate impacts of climate change on herbaceous vegetation.
Potential aboveground biomass in drought-prone forest used for rangeland pastoralism.

PubMed

Fensham, R J; Fairfax, R J; Dwyer, J M

2012-04-01

The restoration of cleared dry forest represents an important opportunity to sequester atmospheric carbon. In order to account for this potential, the influences of climate, soils, and disturbance need to be deciphered. A data set spanning a region defined the aboveground biomass of mulga (Acacia aneura) dry forest and was analyzed in relation to climate and soil variables using a Bayesian model averaging procedure. Mean annual rainfall had an overwhelmingly strong positive effect, with mean maximum temperature (negative) and soil depth (positive) also important. The data were collected after a recent drought, and the amount of recent tree mortality was weakly positively related to a measure of three-year rainfall deficit, and maximum temperature (positive), soil depth (negative), and coarse sand (negative). A grazing index represented by the distance of sites to watering points was not incorporated by the models. Stark management contrasts, including grazing exclosures, can represent a substantial part of the variance in the model predicting biomass, but the impact of management was unpredictable and was insignificant in the regional data set. There was no evidence of density-dependent effects on tree mortality. Climate change scenarios represented by the coincidence of historical extreme rainfall deficit with extreme temperature suggest mortality of 30.1% of aboveground biomass, compared to 21.6% after the recent (2003-2007) drought. Projections for recovery of forest using a mapping base of cleared areas revealed that the greatest opportunities for restoration of aboveground biomass are in the higher-rainfall areas, where biomass accumulation will be greatest and droughts are less intense. These areas are probably the most productive for rangeland pastoralism, and the trade-off between pastoral production and carbon sequestration will be determined by market forces and carbon-trading rules.
Variation in the concentration and age of nonstructural carbon stored in different tree tissues

NASA Astrophysics Data System (ADS)

Richardson, Andrew; Carbone, Mariah; Huggett, Brett; Furze, Morgan; Czimczik, Claudia I.; Xu, Xiaomei

2014-05-01

Trees store nonstructural carbon (NSC), in the form of sugars and starch, in the ray parenchyma cells of woody tissues. These reserves provide a carbon buffer when demand (growth, protection, or metabolism) exceeds supply (photosynthesis). This is particularly important in the context of resilience to stress and disturbance, such as might be associated with various global change factors. However, storage allocation processes and the availability of stored reserves remain poorly understood in woody plants. To better understand how NSC reserves are distributed throughout the tree, and the degree to which NSC reserves mix across ring boundaries and tissue types, we destructively sampled two 30-year-old trees (one red oak, Quercus rubra L., and one white pine, Pinus strobus L.) growing at Harvard Forest, an oak-dominated temperate forest in the northeastern United States. We analyzed stemwood samples (divided into individual rings, bark, and phloem), coarse and fine branches, and coarse (separated into three depths) and fine roots for concentrations of total sugars and starch. For a subset of samples we used the radiocarbon (14C) "bomb spike" method to estimate the mean age of extracted sugars and starch. In oak, stemwood sugar and starch concentrations were highest (50 mg/g) in the youngest (most recently-formed) rings, and dropped off rapidly (to 10 mg/g or less) across the 10 most recent rings. In oak phloem tissue, sugar concentrations were high (90 mg/g) compared to starch (10 mg/g). In pine, sugar concentrations dropped off rapidly across the three most recent rings (from 30 mg/g to 10 mg/g) whereas starch concentrations were low even for the youngest rings (10 mg/g or less). In pine, phloem concentrations of both sugar (190 mg/g) and starch (20 mg/g) were both substantially higher than in oak. Such strong radial trends must be accounted for when scaling up to whole-tree budgets, as whole increment cores cannot properly integrate (on a ring-area basis) across the depth profile. In oak, fine root concentrations of sugar and starch were similar (40 mg/g), and coarse roots had very high concentrations of starch (140 mg/g) compared to sugar (50 mg/g). In pine, fine root concentrations of both sugar and starch (60 mg/g) were higher than in coarse roots (10 mg/g). Coarse root NSC concentrations did not vary substantially along a radial gradient into the root. Even assuming a 1:5 root:shoot ratio, these data indicate that a large portion of the whole-tree NSC budget is stored belowground. For both sugars and starch, the 14C data indicated substantial mixing of new and older carbon across the youngest stemwood rings (up to 5 y), beyond which NSC age increased linearly with ring age. Coarse root NSC age also increased with radial depth and wood tissue age, and root NSC was consistently younger in pine than oak. The fact that NSC age is not constant with radial depth in the aboveground samples demonstrates that NSC reserves cannot be treated as a single, well-mixed pool. Rather, these results are consistent with previous observation suggesting last-in/first-out dynamics. From a modeling standpoint, these results support a simple two-pool structure where new photosynthate not used for current growth or metabolism enters a well-mixed and young "fast" pool, but over time storage in older rings is transferred to a distinct and older "slow" pool with which mixing no longer occurs.
Factors controlling bark decomposition and its role in wood decomposition in five tropical tree species

PubMed Central

Dossa, Gbadamassi G. O.; Paudel, Ekananda; Cao, Kunfang; Schaefer, Douglas; Harrison, Rhett D.

2016-01-01

Organic matter decomposition represents a vital ecosystem process by which nutrients are made available for plant uptake and is a major flux in the global carbon cycle. Previous studies have investigated decomposition of different plant parts, but few considered bark decomposition or its role in decomposition of wood. However, bark can comprise a large fraction of tree biomass. We used a common litter-bed approach to investigate factors affecting bark decomposition and its role in wood decomposition for five tree species in a secondary seasonal tropical rain forest in SW China. For bark, we implemented a litter bag experiment over 12 mo, using different mesh sizes to investigate effects of litter meso- and macro-fauna. For wood, we compared the decomposition of branches with and without bark over 24 mo. Bark in coarse mesh bags decomposed 1.11–1.76 times faster than bark in fine mesh bags. For wood decomposition, responses to bark removal were species dependent. Three species with slow wood decomposition rates showed significant negative effects of bark-removal, but there was no significant effect in the other two species. Future research should also separately examine bark and wood decomposition, and consider bark-removal experiments to better understand roles of bark in wood decomposition. PMID:27698461
Factors controlling bark decomposition and its role in wood decomposition in five tropical tree species.

PubMed

Dossa, Gbadamassi G O; Paudel, Ekananda; Cao, Kunfang; Schaefer, Douglas; Harrison, Rhett D

2016-10-04

Organic matter decomposition represents a vital ecosystem process by which nutrients are made available for plant uptake and is a major flux in the global carbon cycle. Previous studies have investigated decomposition of different plant parts, but few considered bark decomposition or its role in decomposition of wood. However, bark can comprise a large fraction of tree biomass. We used a common litter-bed approach to investigate factors affecting bark decomposition and its role in wood decomposition for five tree species in a secondary seasonal tropical rain forest in SW China. For bark, we implemented a litter bag experiment over 12 mo, using different mesh sizes to investigate effects of litter meso- and macro-fauna. For wood, we compared the decomposition of branches with and without bark over 24 mo. Bark in coarse mesh bags decomposed 1.11-1.76 times faster than bark in fine mesh bags. For wood decomposition, responses to bark removal were species dependent. Three species with slow wood decomposition rates showed significant negative effects of bark-removal, but there was no significant effect in the other two species. Future research should also separately examine bark and wood decomposition, and consider bark-removal experiments to better understand roles of bark in wood decomposition.
Quantifying changes in total and pyrogenic carbon stocks across fire severity gradients using active wildfire incidents

NASA Astrophysics Data System (ADS)

Miesel, Jessica; Reiner, Alicia; Ewell, Carol; Maestrini, Bernardo; Dickinson, Matthew

2018-05-01

Positive feedbacks between wildfire emissions and climate are expected to increase in strength in the future; however, fires not only release carbon (C) from terrestrial to atmospheric pools, they also produce pyrogenic C (PyC) which contributes to longer-term C stability. Our objective was to quantify wildfire impacts on total C and PyC stocks in California mixed-conifer forest, and to investigate relationships between C and PyC stocks and changes across gradients of fire severity, using metrics derived from remote sensing and field observations. Our unique study accessed active wildfires to establish and measure plots within days before and after fire, prior to substantial erosion. We measured pre- and post-fire aboveground forest structure and woody fuels to calculate aboveground biomass, C and PyC, and collected forest floor and 0-5 cm mineral soil samples. Tree mortality increased with severity, but overstory C loss was minimal and limited primarily to foliage. Fire released 85% of understory and herbaceous C (comprising <1.0% of total ecosystem C). The greatest C losses occurred from downed wood and forest floor pools (19.3±5.1 Mg ha-1 and 25.9±3.2 Mg ha-1, respectively). Tree bark and downed wood contributed the greatest PyC gains (1.5±0.3 Mg ha-1 and 1.9±0.8 Mg ha-1, respectively), and PyC in tree bark showed non-significant positive trends with increasing severity. Overall PyC losses of 1.9±0.3 Mg ha-1 and 0.5±0.1 Mg ha-1 occurred from forest floor and 0-5 cm mineral soil, with no clear patterns across severity. Fire resulted in a net ecosystem PyC gain (0.96±0.98 Mg ha-1) across aboveground and belowground components of these forests, and there were no differences among severity levels. Carbon emissions represented only 21.6% of total forest C; however, extensive conversion of C from live to dead pools will contribute to large downed wood C pools susceptible to release in a subsequent fire, indicating that there may be a delayed relationship between fire severity and C emissions. This research advances understanding of forest C loss and stabilization as PyC in wildfires; however, poor relationships between C and PyC gains or losses and fire severity highlight the complexity of fire impacts on forest C.
Testing the generality of above-ground biomass allometry across plant functional types at the continent scale.

PubMed

Paul, Keryn I; Roxburgh, Stephen H; Chave, Jerome; England, Jacqueline R; Zerihun, Ayalsew; Specht, Alison; Lewis, Tom; Bennett, Lauren T; Baker, Thomas G; Adams, Mark A; Huxtable, Dan; Montagu, Kelvin D; Falster, Daniel S; Feller, Mike; Sochacki, Stan; Ritson, Peter; Bastin, Gary; Bartle, John; Wildy, Dan; Hobbs, Trevor; Larmour, John; Waterworth, Rob; Stewart, Hugh T L; Jonson, Justin; Forrester, David I; Applegate, Grahame; Mendham, Daniel; Bradford, Matt; O'Grady, Anthony; Green, Daryl; Sudmeyer, Rob; Rance, Stan J; Turner, John; Barton, Craig; Wenk, Elizabeth H; Grove, Tim; Attiwill, Peter M; Pinkard, Elizabeth; Butler, Don; Brooksbank, Kim; Spencer, Beren; Snowdon, Peter; O'Brien, Nick; Battaglia, Michael; Cameron, David M; Hamilton, Steve; McAuthur, Geoff; Sinclair, Jenny

2016-06-01

Accurate ground-based estimation of the carbon stored in terrestrial ecosystems is critical to quantifying the global carbon budget. Allometric models provide cost-effective methods for biomass prediction. But do such models vary with ecoregion or plant functional type? We compiled 15 054 measurements of individual tree or shrub biomass from across Australia to examine the generality of allometric models for above-ground biomass prediction. This provided a robust case study because Australia includes ecoregions ranging from arid shrublands to tropical rainforests, and has a rich history of biomass research, particularly in planted forests. Regardless of ecoregion, for five broad categories of plant functional type (shrubs; multistemmed trees; trees of the genus Eucalyptus and closely related genera; other trees of high wood density; and other trees of low wood density), relationships between biomass and stem diameter were generic. Simple power-law models explained 84-95% of the variation in biomass, with little improvement in model performance when other plant variables (height, bole wood density), or site characteristics (climate, age, management) were included. Predictions of stand-based biomass from allometric models of varying levels of generalization (species-specific, plant functional type) were validated using whole-plot harvest data from 17 contrasting stands (range: 9-356 Mg ha(-1) ). Losses in efficiency of prediction were <1% if generalized models were used in place of species-specific models. Furthermore, application of generalized multispecies models did not introduce significant bias in biomass prediction in 92% of the 53 species tested. Further, overall efficiency of stand-level biomass prediction was 99%, with a mean absolute prediction error of only 13%. Hence, for cost-effective prediction of biomass across a wide range of stands, we recommend use of generic allometric models based on plant functional types. Development of new species-specific models is only warranted when gains in accuracy of stand-based predictions are relatively high (e.g. high-value monocultures). © 2015 John Wiley & Sons Ltd.
Measuring the Role of Ecological Shift and Environmental Change on Organic Carbon Stocks in Salt Marshes and Mangrove Dominated Wetlands from the Texas Gulf Coast

NASA Astrophysics Data System (ADS)

Norwood, M. J.; Louchouarn, P.; Armitage, A. R.; HighField, W.; Brody, S.; White, N.

2014-12-01

Texas coastal wetlands are dynamic marsh-mangrove ecotones that play an important role in fishery recruitment, storm buffering, and carbon storage. Historically, C4 salt marsh plants, such as Spartina alterniflora, have dominated the Texas Gulf Coast. For the past 2-3 decades, some of these ecosystems have experienced community shifts with woody tropical plants (Avicennia germinans) competing for resources. This study presents new results on the carbon sequestration potential following such ecological shifts as well as coastal development and wetland loss along the coast of Texas. The recorded change from native grass-dominated C4 salt marshes to wood-dominated C3 mangroves over the last 20 years (1990-2010: 4,660 km2) leads to a non-significant loss in aboveground organic carbon (OC) stocks (-6.5.106 g OC). The most substantial loss of aboveground OC in Texas coastal salt marshes is due to the transformation of these wetlands into tidal flats and open water (-7.53.108 g OC). Similarly, the largest losses in aboveground OC stocks from mangrove ecosystems (-1.57.107 g OC) are due to replacement by open water. Along with the decrease in aboveground OC stocks, we identified a significant decrease in sedimentary OC inventories due to the loss of salt marsh and mangrove coverage (-3.69.109 g OC and 5.71.107 g OC, respectively). In contrast, mangrove expansion into mudflat and salt marsh environments led to a positive addition in aboveground OC stocks (2.78.108 g OC) and increased OC sedimentary inventories (2.32.109 g OC). Mangrove expansion offsets only 70% of the total calculated OC loss (-4.51.109 g OC) in coastal wetlands along the Texas gulf coast over the 20-year study period. This deficit loss is primarily attributed to environmental pressures on coastal salt marshes (i.e., sea level rise, urban and coastal development, erosion).
Satellite Based Analysis of Wood Biomass and Fuelwood Sustainability in Senegal: Developing Approaches for Long-Term Monitoring in the SERVIR-West Africa Region

NASA Astrophysics Data System (ADS)

Hanan, N. P.; Anchang, J.; Dieye, A. M.; Yero, K.; Tredennick, A. T.

2017-12-01

Rural populations in most of Africa are highly dependent on woody biomass (wood or charcoal) for cooking and heating. Many rural families gather wood locally, while urban populations often rely on small-scale commercial charcoal producers, who make charcoal in rural areas for transport to urban centers. Given that cooking is essential for conversion of inedible protein and carbohydrate substrates into edible food, fuelwood is an essential part of the food security puzzle for most African families. The SERVIR program is a partnership between USAID, NASA and regional institutions designed to enhance access to, and application of, earth observation data for economic development and natural resource management in less developed countries. In this paper, we report on a SERVIR West Africa collaboration to develop above-ground wood biomass estimates using moderate resolution ( 20 m) data from Sentinel-1 and Sentinel-2 satellites, incorporating field data for calibration and validation, and using data retrieval and analysis workflows that can be replicated by SERVIR partners across the region. Using the country of Senegal as a test case, we analyze the spatial distribution of biomass stocks in relation to fuelwood demand to assess supply-demand patterns across scales from local (village), to district, regional and national scales.
Biomass and nutrient dynamics associated with slash fires in neotropical dry forests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kauffman, J.B.; Cummings, D.L.; Sanford, R.L. Jr.

1993-01-01

Unprecedented rates of deforestation and biomass burning in tropical dry forests are dramatically influencing biogeochemical cycles, resulting in resource depletion, declines in biodiversity, and atmospheric pollution. We quantified the effects of deforestation and varying levels of slash-fire severity on nutrient losses and redistribution in a second-growth tropical dry forest ([open quotes]Caatinga[close quotes]) near Serra Talhada, Pernambuco, Brazil. Total aboveground biomass prior to burning was [approx]74 Mg/ha. Nitrogen and phosphorus concentrations were highest in litter, leaves attached to slash, and fine wood debris (
A Model-Data Intercomparison of Carbon Fluxes, Pools, and LAI in the Community Land Model (CLM) and Alternative Carbon Allocation Schemes

NASA Astrophysics Data System (ADS)

Montane, F.; Fox, A. M.; Arellano, A. F.; Alexander, M. R.; Moore, D. J.

2016-12-01

Carbon (C) allocation to different plant tissues (leaves, stem and roots) remains a central challenge for understanding the global C cycle, as it determines C residence time. We used a diverse set of observations (AmeriFlux eddy covariance towers, biomass estimates from tree-ring data, and Leaf Area Index measurements) to compare C fluxes, pools, and Leaf Area Index (LAI) data with the Community Land Model (CLM). We ran CLM for seven temperate forests in North America (including evergreen and deciduous sites) between 1980 and 2013 using different C allocation schemes: i) standard C allocation scheme in CLM, which allocates C to the stem and leaves as a dynamic function of annual net primary productivity (NPP); ii) two fixed C allocation schemes, one representative of evergreen and the other one of deciduous forests, based on Luyssaert et al. 2007; iii) an alternative C allocation scheme, which allocated C to stem and leaves, and to stem and coarse roots, as a dynamic function of annual NPP, based on Litton et al. 2007. At our sites CLM usually overestimated gross primary production and ecosystem respiration, and underestimated net ecosystem exchange. Initial aboveground biomass in 1980 was largely overestimated for deciduous forests, whereas aboveground biomass accumulation between 1980 and 2011 was highly underestimated for both evergreen and deciduous sites due to the lower turnover rate in the sites than the one used in the model. CLM overestimated LAI in both evergreen and deciduous sites because the Leaf C-LAI relationship in the model did not match the observed Leaf C-LAI relationship in our sites. Although the different C allocation schemes gave similar results for aggregated C fluxes, they translated to important differences in long-term aboveground biomass accumulation and aboveground NPP. For deciduous forests, one of the alternative C allocation schemes used (iii) gave more realistic stem C/leaf C ratios, and highly reduced the overestimation of initial aboveground biomass, and accumulated aboveground NPP for deciduous forests by CLM. Our results would suggest using different C allocation schemes for evergreen and deciduous forests. It is crucial to improve CLM in the near future to minimize data-model mismatches, and to address some of the current model structural errors and parameter uncertainties.
Arthropods in Decomposing Wood of the Atchafalaya River Basin

Treesearch

B.G. Lockaby; B.D. Keeland; John A. Stanturf; M.D. Rice; G. Hodges; R.M. Governo

2002-01-01

Changes in arthropod populations (numbers of individuals identified to the family level in most cases) were studied during the decomposition of coarse woody debris (CWD) in the Atchafalaya River Basin of Louisiana. The arthropod study was linked with a CWD decomposition study installed after disturbance by Hurricane Andrew. Arthropod numbers were compared between two...
Diversity of lignicolous basidiomycetes in coarse woody debris

Treesearch

K. K. Nakasone

1993-01-01

Basidiomycetes are the most conspicuous fungi on wood and are the main decomposers. Lignicolous basidiomycetes include white-rotters that remove both lignin and cellulose, and brown-rotters that remove only the cellulose and hemicellulose. The South is a region of diverse lignicolous basidiomycetes because it is the northern limit for many tropical and subtropical...
Adaptation to wildfire: A fish story

Treesearch

John Kirkland; Rebecca Flitcroft; Gordon Reeves; Paul Hessburg

2017-01-01

In the Pacific Northwest, native salmon and trout are some of the toughest survivors on the block. Over time, these fish have evolved behavioral adaptations to natural disturbances, and they rely on these disturbances to deliver coarse sediment and wood that become complex stream habitat. Powerful disturbances such as wildfire, postfire landslides, and debris flows may...
Relationship between wood-inhabiting fungi and Reticulitermes spp

Treesearch

Grant T. Kirker; Terence Wagner; Susan Diehl

2012-01-01

Fungi from coarse woody debris samples containing or lacking termites were isolated, and identified from upland and bottomland hardwoods and pines in northeast Mississippi. Samples yielded 860 unique fungal isolates, with 59% identified to genus level. Four phyla, six classes, 10 orders, 14 families, and 50 genera were recovered. The fungal groups encountered by...
Thermal Transmittance of Porous Hollow Clay Brick by Guarded Hot Box Method

NASA Astrophysics Data System (ADS)

Kim, Joonsoo

2018-03-01

The thermal property of a porous hollow clay brick was determined by measuring the thermal transmittance of the wall made of porous hollow clay bricks. Prior to the production of porous hollow clay bricks, nonporous and porous tiny clay bricks were prepared to determine the physico-mechanical properties by modifying the amount of wood flour and firing temperature. The bricks were produced by uniaxial pressing and then fired in an electric furnace. Their physico-mechanical properties were measured by water absorption, apparent porosity, bulk density, and compressive strength. The porous tiny clay bricks were produced with three types of wood flour: coarse wood flour (1-0.36 mm), medium-sized wood flour (0.36-0.15 mm), and fine wood flour (< 0.08 mm). The thermal transmittance of porous hollow clay bricks was determined through the guarded hot box method, which measures the wall made of porous hollow clay bricks and nonporous cement bricks. The two walls had a thermal transmittance of 1.42 and 2.72 W\\cdot m^{-2}\\cdot K^{-1}, respectively. The difference in thermal transmittance was due to the pores created with fine wood flour (< 0.08 mm) as a pore-forming agent.
Wood CO(2) efflux and foliar respiration for Eucalyptus in Hawaii and Brazil.

PubMed

Ryan, Michael G; Cavaleri, Molly A; Almeida, Auro C; Penchel, Ricardo; Senock, Randy S; Luiz Stape, José

2009-10-01

We measured CO(2) efflux from wood for Eucalyptus in Hawaii for 7 years and compared these measurements with those on three- and four-and-a-half-year-old Eucalyptus in Brazil. In Hawaii, CO(2) efflux from wood per unit biomass declined approximately 10x from age two to age five, twice as much as the decline in tree growth. The CO(2) efflux from wood in Brazil was 8-10x lower than that for comparable Hawaii trees with similar growth rates. Growth and maintenance respiration coefficients calculated from Hawaii wood CO(2) efflux declined with tree age and size (the growth coefficient declined from 0.4 mol C efflux mol C(-1) wood growth at age one to 0.1 mol C efflux mol C(-1) wood growth at age six; the maintenance coefficient from 0.006 to 0.001 micromol C (mol C biomass)(-1) s(-1) at 20 degrees C over the same time period). These results suggest interference with CO(2) efflux through bark that decouples CO(2) efflux from respiration. We also compared the biomass fractions and wood CO(2) efflux for the aboveground woody parts for 3- and 7-year-old trees in Hawaii to estimate how focusing measurements near the ground might bias the stand-level estimates of wood CO(2) efflux. Three-year-old Eucalyptus in Hawaii had a higher proportion of branches < 0.5 cm in diameter and a lower proportion of stem biomass than did 7-year-old trees. Biomass-specific CO(2) efflux measured at 1.4 m extrapolated to the tree could bias tree level estimates by approximately 50%, assuming no refixation from bark photosynthesis. However, the bias did not differ for the two tree sizes. Foliar respiration was identical per unit nitrogen for comparable treatments in Brazil and Hawaii (4.2 micromol C mol N(-1) s(-1) at 20 degrees C).
The outcome of ecosystem manipulation by elevating atmospheric CO2 is influenced by tree identity and mixture

NASA Astrophysics Data System (ADS)

Godbold, Douglas; Smith, Andrew; Lukac, Martin

2013-04-01

Free Air Carbon dioxide Enrichment (FACE) has often been used predict the response of forest ecosystems to a future high CO2 world. Many of these investigations have been restricted to exposure of single species or genotypes to elevated CO2. To investigate the interaction between tree mixture and elevated CO2, Alnus glutinosa, Betula pendula and Fagus sylvatica were planted in areas of single species and a three species polyculture in a free-air CO2 enrichment study (BangorFACE). The trees were exposed to ambient or elevated CO2 for 4 years. Aboveground woody biomass was increased in polyculture under both ambient and elevated CO2, but the response to elevated CO2 was smaller in polyculture than in the monocultures. In some years, a longer leaf retention was shown under high CO2, and is an indication that environmental factors may moderate tree response to high CO2. Fine and coarse root biomass, together with fine root turnover and fine root morphological characteristics were also measured. Fine root biomass and morphology responded differentially to the elevated CO2 at different soil depths in the three species when grown in monocultures. In polyculture, a greater response to elevated CO2 was observed in coarse roots, and fine root area index. Total fine root biomass was positively affected by elevated CO2 at the end of the experiment, but not by species diversity. Our results show that the aboveground and belowground response to elevated CO2 is significantly affected by intra- and inter-specific competition, and that elevated CO2 response may be reduced in forest communities comprised of tree species with contrasting functional traits but also that other environmental factors may induce previously unseen effects.

Reducing indoor air pollutants with air filtration units in wood stove homes.

PubMed

McNamara, Marcy L; Thornburg, Jonathon; Semmens, Erin O; Ward, Tony J; Noonan, Curtis W

2017-08-15

Biomass burning has been shown to be a major source of poor indoor air quality (IAQ) in developing and higher income countries across the world. Specifically, wood burning for cooking and heating contributes to high indoor concentrations of fine (particles with aerodynamic diameters<2.5μm; PM 2.5 ) and coarse (particles with aerodynamic diameters <10μm and >2.5μm; PMc) particulate matter. Endotoxin, predominantly found within the coarse fraction of airborne particulate matter, is associated with proinflammatory effects and adverse outcomes among susceptible populations. The aim of this study was to assess the efficacy of air filter interventions in reducing indoor PM 2.5 , PMc, and PMc-associated endotoxin concentrations in homes using a wood stove for primary heating. Homes (n=48) were randomized to receive in-room air filtration units with either a high efficiency filter (i.e. active) or a lower efficiency fiberglass filter (i.e., placebo). The active filter intervention showed a 66% reduction in indoor PM 2.5 concentrations (95% CI: 42.2% to 79.7% reduction) relative to the placebo intervention. Both the active and the placebo filters were effective in substantially reducing indoor concentrations of PMc (63.3% and 40.6% average reduction for active and placebo filters, respectively) and PMc-associated endotoxin concentrations (91.8% and 80.4% average reductions, respectively). These findings support the use of high efficiency air filtration units for reducing indoor PM 2.5 in homes using a wood stove for primary heating. We also discovered that using lower efficiency, lower cost filter alternatives can be effective for reducing PMc and airborne endotoxin in homes burning biomass fuel. Copyright © 2017. Published by Elsevier B.V.
A comparison of two above-ground biomass estimation techniques integrating satellite-based remotely sensed data and ground data for tropical and semiarid forests in Puerto Rico

NASA Astrophysics Data System (ADS)

Iiames, J. S.; Riegel, J.; Lunetta, R.

2013-12-01

Two above-ground forest biomass estimation techniques were evaluated for the United States Territory of Puerto Rico using predictor variables acquired from satellite based remotely sensed data and ground data from the U.S. Department of Agriculture Forest Inventory Analysis (FIA) program. The U.S. Environmental Protection Agency (EPA) estimated above-ground forest biomass implementing methodology first posited by the Woods Hole Research Center developed for conterminous United States (National Biomass and Carbon Dataset [NBCD2000]). For EPA's effort, spatial predictor layers for above-ground biomass estimation included derived products from the U.S. Geologic Survey (USGS) National Land Cover Dataset 2001 (NLCD) (landcover and canopy density), the USGS Gap Analysis Program (forest type classification), the USGS National Elevation Dataset, and the NASA Shuttle Radar Topography Mission (tree heights). In contrast, the U.S. Forest Service (USFS) biomass product integrated FIA ground-based data with a suite of geospatial predictor variables including: (1) the Moderate Resolution Imaging Spectrometer (MODIS)-derived image composites and percent tree cover; (2) NLCD land cover proportions; (3) topographic variables; (4) monthly and annual climate parameters; and (5) other ancillary variables. Correlations between both data sets were made at variable watershed scales to test level of agreement. Notice: This work is done in support of EPA's Sustainable Healthy Communities Research Program. The U.S EPA funded and conducted the research described in this paper. Although this work was reviewed by the EPA and has been approved for publication, it may not necessarily reflect official Agency policy. Mention of any trade names or commercial products does not constitute endorsement or recommendation for use.
The Oldest, Slowest Rainforests in the World? Massive Biomass and Slow Carbon Dynamics of Fitzroya cupressoides Temperate Forests in Southern Chile.

PubMed

Urrutia-Jalabert, Rocio; Malhi, Yadvinder; Lara, Antonio

2015-01-01

Old-growth temperate rainforests are, per unit area, the largest and most long-lived stores of carbon in the terrestrial biosphere, but their carbon dynamics have rarely been described. The endangered Fitzroya cupressoides forests of southern South America include stands that are probably the oldest dense forest stands in the world, with long-lived trees and high standing biomass. We assess and compare aboveground biomass, and provide the first estimates of net primary productivity (NPP), carbon allocation and mean wood residence time in medium-age stands in the Alerce Costero National Park (AC) in the Coastal Range and in old-growth forests in the Alerce Andino National Park (AA) in the Andean Cordillera. Aboveground live biomass was 113-114 Mg C ha(-1) and 448-517 Mg C ha(-1) in AC and AA, respectively. Aboveground productivity was 3.35-3.36 Mg C ha(-1) year(-1) in AC and 2.22-2.54 Mg C ha(-1) year(-1) in AA, values generally lower than others reported for temperate wet forests worldwide, mainly due to the low woody growth of Fitzroya. NPP was 4.21-4.24 and 3.78-4.10 Mg C ha(-1) year(-1) in AC and AA, respectively. Estimated mean wood residence time was a minimum of 539-640 years for the whole forest in the Andes and 1368-1393 years for only Fitzroya in this site. Our biomass estimates for the Andes place these ecosystems among the most massive forests in the world. Differences in biomass production between sites seem mostly apparent as differences in allocation rather than productivity. Residence time estimates for Fitzroya are the highest reported for any species and carbon dynamics in these forests are the slowest reported for wet forests worldwide. Although primary productivity is low in Fitzroya forests, they probably act as ongoing biomass carbon sinks on long-term timescales due to their low mortality rates and exceptionally long residence times that allow biomass to be accumulated for millennia.
The Oldest, Slowest Rainforests in the World? Massive Biomass and Slow Carbon Dynamics of Fitzroya cupressoides Temperate Forests in Southern Chile

PubMed Central

Urrutia-Jalabert, Rocio; Malhi, Yadvinder; Lara, Antonio

2015-01-01

Old-growth temperate rainforests are, per unit area, the largest and most long-lived stores of carbon in the terrestrial biosphere, but their carbon dynamics have rarely been described. The endangered Fitzroya cupressoides forests of southern South America include stands that are probably the oldest dense forest stands in the world, with long-lived trees and high standing biomass. We assess and compare aboveground biomass, and provide the first estimates of net primary productivity (NPP), carbon allocation and mean wood residence time in medium-age stands in the Alerce Costero National Park (AC) in the Coastal Range and in old-growth forests in the Alerce Andino National Park (AA) in the Andean Cordillera. Aboveground live biomass was 113–114 Mg C ha-1 and 448–517 Mg C ha-1 in AC and AA, respectively. Aboveground productivity was 3.35–3.36 Mg C ha-1 year-1 in AC and 2.22–2.54 Mg C ha-1 year-1 in AA, values generally lower than others reported for temperate wet forests worldwide, mainly due to the low woody growth of Fitzroya. NPP was 4.21–4.24 and 3.78–4.10 Mg C ha-1 year-1 in AC and AA, respectively. Estimated mean wood residence time was a minimum of 539–640 years for the whole forest in the Andes and 1368–1393 years for only Fitzroya in this site. Our biomass estimates for the Andes place these ecosystems among the most massive forests in the world. Differences in biomass production between sites seem mostly apparent as differences in allocation rather than productivity. Residence time estimates for Fitzroya are the highest reported for any species and carbon dynamics in these forests are the slowest reported for wet forests worldwide. Although primary productivity is low in Fitzroya forests, they probably act as ongoing biomass carbon sinks on long-term timescales due to their low mortality rates and exceptionally long residence times that allow biomass to be accumulated for millennia. PMID:26353111
Assessing the performance of multi-purpose channel management measures at increasing scales

NASA Astrophysics Data System (ADS)

Wilkinson, Mark; Addy, Steve

2016-04-01

In addition to hydroclimatic drivers, sediment deposition from high energy river systems can reduce channel conveyance capacity and lead to significant increases in flood risk. There is an increasing recognition that we need to work with the interplay of natural hydrological and morphological processes in order to attenuate flood flows and manage sediment (both coarse and fine). This typically includes both catchment (e.g. woodland planting, wetlands) and river (e.g. wood placement, floodplain reconnection) restoration approaches. The aim of this work was to assess at which scales channel management measures (notably wood placement and flood embankment removal) are most appropriate for flood and sediment management in high energy upland river systems. We present research findings from two densely instrumented research sites in Scotland which regularly experience flood events and have associated coarse sediment problems. We assessed the performance of a range of novel trial measures for three different scales: wooded flow restrictors and gully tree planting at the small scale (<1 km2), floodplain tree planting and engineered log jams at the intermediate scale (5-60 km2), and flood embankment lowering at the large scale (350 km2). Our results suggest that at the smallest scale, care is needed in the installation of flow restrictors. It was found for some restrictors that vertical erosion can occur if the tributary channel bed is disturbed. Preliminary model evidence suggested they have a very limited impact on channel discharge and flood peak delay owing to the small storage areas behind the structures. At intermediate scales, the ability to trap sediment by engineered log jams was limited. Of the 45 engineered log jams installed, around half created a small geomorphic response and only 5 captured a significant amount of coarse material (during one large flood event). As scale increases, the chance of damage or loss of wood placement is greatest. Monitoring highlights the importance of structure design (porosity and degree of channel blockage) and placement in zones of high sediment transport to optimise performance. At the large scale, well designed flood embankment lowering can improve connectivity to the floodplain during low to medium return period events. However, ancillary works to stabilise the bank failed thus emphasising the importance of letting natural processes readjust channel morphology and hydrological connections to the floodplain. Although these trial measures demonstrated limited effects, this may be in part owing to restrictions in the range of hydroclimatological conditions during the study period and further work is needed to assess the performance under more extreme conditions. This work will contribute to refining guidance for managing channel coarse sediment problems in the future which in turn could help mitigate flooding using natural approaches.
Carbon storage in old-growth forests of the Mid-Atlantic: toward better understanding the eastern forest carbon sink.

PubMed

McGarvey, Jennifer C; Thompson, Jonathan R; Epstein, Howard E; Shugart, Herman H

2015-02-01

Few old-growth stands remain in the matrix of secondary forests that dominates the eastern North American landscape. These remnant stands offer insight on the potential carbon (C) storage capacity of now-recovering secondary forests. We surveyed the remaining old-growth forests on sites characteristic of the general Mid-Atlantic United States and estimated the size of multiple components of forest C storage. Within and between old-growth stands, variability in C density is high and related to overstory tree species composition. The sites contain 219 ± 46 Mg C/ha (mean ± SD), including live and dead aboveground biomass, leaf litter, and the soil O horizon, with over 20% stored in downed wood and snags. Stands dominated by tulip poplar (Liriodendron tulipifera) store the most live biomass, while the mixed oak (Quercus spp.) stands overall store more dead wood. Total C density is 30% higher (154 Mg C/ha), and dead wood C density is 1800% higher (46 Mg C/ha) in the old-growth forests than in the surrounding younger forests (120 and 5 Mg C/ha, respectively). The high density of dead wood in old growth relative to secondary forests reflects a stark difference in historical land use and, possibly, the legacy of the local disturbance (e.g., disease) history. Our results demonstrate the potential for dead wood to maintain the sink capacity of secondary forests for many decades to come.
Evaluation of stem rot in 339 Bornean tree species: implications of size, taxonomy, and soil-related variation for aboveground biomass estimates

NASA Astrophysics Data System (ADS)

Heineman, K. D.; Russo, S. E.; Baillie, I. C.; Mamit, J. D.; Chai, P. P.-K.; Chai, L.; Hindley, E. W.; Lau, B.-T.; Tan, S.; Ashton, P. S.

2015-10-01

Fungal decay of heart wood creates hollows and areas of reduced wood density within the stems of living trees known as stem rot. Although stem rot is acknowledged as a source of error in forest aboveground biomass (AGB) estimates, there are few data sets available to evaluate the controls over stem rot infection and severity in tropical forests. Using legacy and recent data from 3180 drilled, felled, and cored stems in mixed dipterocarp forests in Sarawak, Malaysian Borneo, we quantified the frequency and severity of stem rot in a total of 339 tree species, and related variation in stem rot with tree size, wood density, taxonomy, and species' soil association, as well as edaphic conditions. Predicted stem rot frequency for a 50 cm tree was 53 % of felled, 39 % of drilled, and 28 % of cored stems, demonstrating differences among methods in rot detection ability. The percent stem volume infected by rot, or stem rot severity, ranged widely among trees with stem rot infection (0.1-82.8 %) and averaged 9 % across all trees felled. Tree taxonomy explained the greatest proportion of variance in both stem rot frequency and severity among the predictors evaluated in our models. Stem rot frequency, but not severity, increased sharply with tree diameter, ranging from 13 % in trees 10-30 cm DBH to 54 % in stems ≥ 50 cm DBH across all data sets. The frequency of stem rot increased significantly in soils with low pH and cation concentrations in topsoil, and stem rot was more common in tree species associated with dystrophic sandy soils than with nutrient-rich clays. When scaled to forest stands, the maximum percent of stem biomass lost to stem rot varied significantly with soil properties, and we estimate that stem rot reduces total forest AGB estimates by up to 7 % relative to what would be predicted assuming all stems are composed strictly of intact wood. This study demonstrates not only that stem rot is likely to be a significant source of error in forest AGB estimation, but also that it strongly covaries with tree size, taxonomy, habitat association, and soil resources, underscoring the need to account for tree community composition and edaphic variation in estimating carbon storage in tropical forests.
Field results for line intersect distance sampling of coarse woody debris

Treesearch

David L. R. Affleck

2009-01-01

A growing recognition of the importance of downed woody materials in forest ecosystem processes and global carbon budgets has sharpened the need for efficient sampling strategies that target this resource. Often the aggregate volume, biomass, or carbon content of the downed wood is of primary interest, making recently developed probability proportional-to-volume...
Hydrogeologic framework of the Wood River Valley aquifer system, south-central Idaho

USGS Publications Warehouse

Bartolino, James R.; Adkins, Candice B.

2012-01-01

The Wood River Valley contains most of the population of Blaine County and the cities of Sun Valley, Ketchum, Hailey, and Bellevue. This mountain valley is underlain by the alluvial Wood River Valley aquifer system, which consists primarily of a single unconfined aquifer that underlies the entire valley, an underlying confined aquifer that is present only in the southernmost valley, and the confining unit that separates them. The entire population of the area depends on groundwater for domestic supply, either from domestic or municipal-supply wells, and rapid population growth since the 1970s has caused concern about the long-term sustainability of the groundwater resource. As part of an ongoing U.S. Geological Survey effort to characterize the groundwater resources of the Wood River Valley, this report describes the hydrogeologic framework of the Wood River Valley aquifer system. Although most of the Wood River Valley aquifer system is composed of Quaternary-age sediments and basalts of the Wood River Valley and its tributaries, older igneous, sedimentary, or metamorphic rocks that underlie these Quaternary deposits also are used for water supply. It is unclear to what extent these rocks are hydraulically connected to the main part of Wood River Valley aquifer system and thus whether they constitute separate aquifers. Paleozoic sedimentary rocks in and near the study area that produce water to wells and springs are the Phi Kappa and Trail Creek Formations (Ordovician and Silurian), the Milligen Formation (Devonian), and the Sun Valley Group including the Wood River Formation (Pennsylvanian-Permian) and the Dollarhide Formation (Permian). These sedimentary rocks are intruded by granitic rocks of the Late Cretaceous Idaho batholith. Eocene Challis Volcanic Group rocks overlie all of the older rocks (except where removed by erosion). Miocene Idavada Volcanics are found in the southern part of the study area. Most of these rocks have been folded, faulted, and metamorphosed to some degree, thus rock types and their relationships vary over distance. Quaternary-age sediment and basalt compose the primary source of groundwater in the Wood River Valley aquifer system. These Quaternary deposits can be divided into three units: a coarse-grained sand and gravel unit, a fine-grained silt and clay unit, and a single basalt unit. The fine- and coarse-grained units were primarily deposited as alluvium derived from glaciation in the surrounding mountains and upper reaches of tributary canyons. The basalt unit is found in the southeastern Bellevue fan area and is composed of two flows of different ages. Most of the groundwater produced from the Wood River Valley aquifer system is from the coarse-grained deposits. The altitude of the pre-Quaternary bedrock surface in the Wood River Valley was compiled from about 1,000 well-driller reports for boreholes drilled to bedrock and about 70 Horizontal-to-Vertical Spectral Ratio (HVSR) ambient-noise measurements. The bedrock surface generally mimics the land surface by decreasing down tributary canyons and the main valley from north to south; it ranges from more than 6,700 feet in Baker Creek to less than 4,600 feet in the central Bellevue fan. Most of the south-central portion of the Bellevue fan is underlain by an apparent topographically closed area on the bedrock surface that appears to drain to the southwest towards Stanton Crossing. Quaternary sediment thickness ranges from less than a foot on main and tributary valley margins to about 350 feet in the central Bellevue fan. Hydraulic conductivity for 81 wells in the study area was estimated from well-performance tests reported on well-driller reports. Estimated hydraulic conductivity for 79 wells completed in alluvium ranges from 1,900 feet per day (ft/d) along Warm Springs Creek to less than 1 ft/d in upper Croy Canyon. A well completed in bedrock had an estimated hydraulic conductivity value of 10 ft/d, one well completed in basalt had a value of 50 ft/d, and three wells completed in the confined system had values ranging from 32 to 52 ft/d. Subsurface outflow of groundwater from the Wood River Valley aquifer system into the eastern Snake River Plain aquifer was estimated to be 4,000 acre-feet per year. Groundwater outflow beneath Stanton Crossing to the Camas Prairie was estimated to be 300 acre-feet per year.
Estimating fluvial wood discharge from timelapse photography with varying sampling intervals

NASA Astrophysics Data System (ADS)

Anderson, N. K.

2013-12-01

There is recent focus on calculating wood budgets for streams and rivers to help inform management decisions, ecological studies and carbon/nutrient cycling models. Most work has measured in situ wood in temporary storage along stream banks or estimated wood inputs from banks. Little effort has been employed monitoring and quantifying wood in transport during high flows. This paper outlines a procedure for estimating total seasonal wood loads using non-continuous coarse interval sampling and examines differences in estimation between sampling at 1, 5, 10 and 15 minutes. Analysis is performed on wood transport for the Slave River in Northwest Territories, Canada. Relative to the 1 minute dataset, precision decreased by 23%, 46% and 60% for the 5, 10 and 15 minute datasets, respectively. Five and 10 minute sampling intervals provided unbiased equal variance estimates of 1 minute sampling, whereas 15 minute intervals were biased towards underestimation by 6%. Stratifying estimates by day and by discharge increased precision over non-stratification by 4% and 3%, respectively. Not including wood transported during ice break-up, the total minimum wood load estimated at this site is 3300 × 800$ m3 for the 2012 runoff season. The vast majority of the imprecision in total wood volumes came from variance in estimating average volume per log. Comparison of proportions and variance across sample intervals using bootstrap sampling to achieve equal n. Each trial was sampled for n=100, 10,000 times and averaged. All trials were then averaged to obtain an estimate for each sample interval. Dashed lines represent values from the one minute dataset.
Allometric growth and allocation in forests: a perspective from FLUXNET.

PubMed

Wolf, Adam; Field, Christopher B; Berry, Joseph A

2011-07-01

To develop a scheme for partitioning the products of photosynthesis toward different biomass components in land-surface models, a database on component mass and net primary productivity (NPP), collected from FLUXNET sites, was examined to determine allometric patterns of allocation. We found that NPP per individual of foliage (Gfol), stem and branches (Gstem), coarse roots (Gcroot) and fine roots (Gfroot) in individual trees is largely explained (r2 = 67-91%) by the magnitude of total NPP per individual (G). Gfol scales with G isometrically, meaning it is a fixed fraction of G ( 25%). Root-shoot trade-offs were manifest as a slow decline in Gfroot, as a fraction of G, from 50% to 25% as stands increased in biomass, with Gstem and Gcroot increasing as a consequence. These results indicate that a functional trade-off between aboveground and belowground allocation is essentially captured by variations in G, which itself is largely governed by stand biomass and only secondarily by site-specific resource availability. We argue that forests are characterized by strong competition for light, observed as a race for individual trees to ascend by increasing partitioning toward wood, rather than by growing more leaves, and that this competition stronglyconstrains the allocational plasticity that trees may be capable of. The residual variation in partitioning was not related to climatic or edaphic factors, nor did plots with nutrient or water additions show a pattern of partitioning distinct from that predicted by G alone. These findings leverage short-term process studies of the terrestrial carbon cycle to improve decade-scale predictions of biomass accumulation in forests. An algorithm for calculating partitioning in land-surface models is presented.
Composition and Sources of Fine and Coarse Particles Collected during 2002–2010 in Boston, MA

PubMed Central

Masri, Shahir; Kang, Choong-Min; Koutrakis, Petros

2016-01-01

Identifying the sources, composition, and temporal variability of fine (PM2.5) and coarse (PM2.5-10) particles is a crucial component in understanding PM toxicity and establishing proper PM regulations. In this study, a Harvard Impactor was used to collect daily integrated fine and coarse particle samples every third day for nine years at a single site in Boston, MA. A total of 1,960 filters were analyzed for elements, black carbon (BC), and total PM mass. Positive Matrix Factorization (PMF) was used to identify source types and quantify their contributions to ambient PM2.5 and PM2.5-10. BC and 17 elements were identified as the main constituents in our samples. Results showed that BC, S, and Pb were associated exclusively with the fine particle mode, while 84% of V and 79% of Ni were associated with this mode. Elements mostly found in the coarse mode, over 80%, included Ca, Mn (road dust), and Cl (sea salt). PMF identified six source types for PM2.5 and three source types for PM2.5-10. Source types for PM2.5 included regional pollution, motor vehicles, sea salt, crustal/road dust, oil combustion, and wood burning. Regional pollution contributed the most, accounting for 48% of total PM2.5 mass, followed by motor vehicles (21%) and wood burning (19%). Source types for PM2.5-10 included crustal/road dust (62%), motor vehicles (22%), and sea salt (16%). A linear decrease in PM concentrations with time was observed for both fine (−5.2%/yr) and coarse (−3.6%/yr) particles. The fine-mode trend was mostly related to oil combustion and regional pollution contributions. Average PM2.5 concentrations peaked in summer (10.4 μg/m3) while PM2.5-10 concentrations were lower and demonstrated little seasonal variability. The findings of this study show that PM25 is decreasing more sharply than PM2.5-10 over time. This suggests the increasing importance of PM2.5-10 and traffic-related sources for PM exposure and future policies. PMID:25947125
Using aerial photography to estimate wood suitable for charcoal in managed oak forests

NASA Astrophysics Data System (ADS)

Ramírez-Mejía, D.; Gómez-Tagle, A.; Ghilardi, A.

2018-02-01

Mexican oak forests (genus Quercus) are frequently used for traditional charcoal production. Appropriate management programs are needed to ensure their long-term use, while conserving the biodiversity and ecosystem services, and associated benefits. A key variable needed to design these programs is the spatial distribution of standing woody biomass. A state-of-the-art methodology using small format aerial photographs was developed to estimate the total aboveground biomass (AGB) and aboveground woody biomass suitable for charcoal making (WSC) in intensively managed oak forests. We used tree crown area (CAap) measurements from very high-resolution (30 cm) orthorectified small format digital aerial photographs as the predictive variable. The CAap accuracy was validated using field measurements of the crown area (CAf). Allometric relationships between: (a) CAap versus AGB, and (b) CAap versus WSC had a high significance level (R 2 > 0.91, p < 0.0001). This approach shows that it is possible to obtain sound biomass estimates as a function of the crown area derived from digital small format aerial photographs.
Pulpwood Chip Productions and Markets in the Lake States

Treesearch

Eugene W. Fobes

1966-01-01

As a major pulp and paper production area, the Lake States is a potential market for pulpwood chips. As a producer of solid wood products, it has a considerable potential for the production of pulpwood chips from coarse sawmill residues (slabs, edgings, and trim) and other sources. Only a small amount of the available residues, however, is now being utilized. In...
Sharing rotting wood in the shade: ectomycorrhizal communities of co-occurring birch and hemlock seedlings

Treesearch

Sarah K. Poznanovic; Erik A. Lilleskov; Christopher R. Webster

2015-01-01

Coarse woody debris (CWD) is an important nursery environment for many tree species. Understanding the communities of ectomycorrhizal fungi (ECMF) and the effect of ECMF species on tree seedling condition in CWD will elucidate the potential for ECMF-mediated effects on seedling dynamics. In hemlock-dominated stands, we characterized ECMF communities associated with...
Quantitative and qualitative measures of decomposition: is there a link?

Treesearch

Robert J. Eaton; Felipe G. Sanchez

2009-01-01

Decomposition rates of loblolly pine coarse woody debris (CWD) were determined by mass loss and wood density changes for trees that differed in source of mortality (natural, girdle-poison, and felling). Specifically, three treatments were examined: (1) control (CON): natural mortality; (2) CD: 5-fold increase in CWD compared with the CON; and (3) CS: 12-fold increase...
Wood Export and Deposition Dynamics in Mountain Watersheds

NASA Astrophysics Data System (ADS)

Senter, Anne Elizabeth

Wood dynamics that store, transport, break down, and ultimately export wood pieces through watershed networks are key elements of stream complexity and ecosystem health. Efforts to quantify wood processes are advancing rapidly as technological innovations in field data collection, remotely sensed data acquisition, and data analyses become increasingly sophisticated. The ability to extend the temporal and spatial scales of wood data acquisition has been particularly useful to the investigations presented herein. The primary contributions of this dissertation are focused on two aspects of wood dynamics: watershed-scale wood export processes as identified using the depositional environment of a mountain reservoir, and wood deposition mechanisms in a bedrock-dominated mountain river. Three chapters present this work: In Chapter 1, continuous video monitoring of wood in transport revealed seasonal and diurnal hydrologic cycle influences on the variable rates at which wood transports. This effort supports the efficacy of utilizing continuous data collection methods for wood transport studies. Annual wood export data were collected via field efforts and aerial image analyses from New Bullards Bar Reservoir on the North Yuba River, Sierra Nevada, California. Examination of data revealed linkages between decadal-scale climatic patterns, large flood events, and episodic wood export quantities. A watershed-specific relation between wood export quantities and annual peak discharge contributes to the notion that peak discharge is a primary control on wood export, and yielded prediction of annual wood export quantities where no data were available. Linkages between seasonality, climatic components, and hydrologic events that exert variable control on watershed scale wood responses are presented as a functional framework. An accompanying conceptual model supports the framework presumption that wood responses are influenced by seasonal variations in Mediterranean-montane climate conditions and accompanying hydrologic responses. Chapter 2 contains development of new theory in support of the introduction of multiplicative coefficients, categorized by water year type, that were used to predict wood export quantities via utilization of an existing discharge-based theoretical equation. This new theory was the product of continued investigations into watershed-scale factors in search of explanation of observed variation of wood export rates into New Bullards Bar Reservoir. The gap between known variability and the attribution of wood export to one hydrologic relation continues to be a persistent issue, as the hierarchical and stochastic temporal and spatial nature of wood budget components remain difficult to quantify. The development of "watershed processes" coefficients was specifically focused on a generalized, parsimonious approach using water year type categories, with validation exercises supporting the approach. In dry years, predictions more closely represented observed wood export quantities, whereas the previously derived annual peak discharge relation yielded large over-predictions. Additional data are needed to continue development of these watershed-specific coefficients. This new approach to wood export prediction may be beneficial in regulated river systems for planning purposes, and its efficacy could be tested in other watersheds. Chapter 3 presents the results of an investigation into wood deposition mechanisms in a 12.2 km segment of the confined, bedrock-dominated South Yuba River watershed. Inclusion of coarse wood particles in the analyses was essential in recognizing depositional patterns, thus supporting the value of utilizing a wider wood-size range. A near-census data collection effort yielded myriad data, of which topographic wetted width and bed elevation data, developed for an observed 4.5-year flood event, were standardized in 10-m intervals and then univariate and linked values were ordered into landform classifications using decision tree analyses. Digital imagery collected via kite-blimp was mosaicked into a geographic information system and all resolvable wood pieces greater then 2.5 cm in one dimension were delineated and categorized into piece count density classes. Visual imagery was also key in identifying two river corridor terrains: bedrock outcrops and cobble-boulder-vegetation patches. A conceptual model framed an investigation into how topographic variability and structural elements might influence observed wood deposition dynamics. Forage ratio test results that quantified wood piece utilization versus interval availability revealed that high-density wood deposition patterns were most significantly co-located with five discrete bedrock outcrops that dominated small portions of the river corridor in high flow conditions. Topographic variations and cobble-boulder-vegetation patches were found to be subordinate factors in wood deposition patterns. Bedrock outcrops with specific structural components were the primary depositional environments that acted as floodplain extents for coarse wood deposition, with mechanisms such as topographic steering, eddying, trapping, stranding, backwater effects, and lateral roughness features inferred to be responsible for observed wood deposition patterns.
The importance of mercury in leaves, bark and wood of eight tree species across four northeastern forests

NASA Astrophysics Data System (ADS)

Yanai, R. D.; Yang, Y.; Driscoll, C. T.; Montesdeoca, M.

2016-12-01

Mercury (Hg) deposition affects forests even in remote areas, but the amount of Hg in trees is not well known, in part because concentrations of Hg in wood are often below the analytical detection limit by ICP-OES. We analyzed Hg in wood, bark, and foliage of 8 tree species across four sites (Huntington Forest, NY; Sleepers River, VT; Hubbard Brook, NH; Bear Brook, ME) in the northeastern USA, using thermal decomposition, catalytic conversion, amalgamation, and atomic absorption spectrophotometry (USEPA Method 7473). The hardwood species, namely American beech (Fagus grandifolia Ehrh.), white ash (Fraxinus americana L.), yellow birch (Betula alleghaniensis Britt.), sugar maple (Acer saccharum Marshall.), and red maple (Acer rubrum L.), had lower Hg concentrations (averaging 7.7 ng g-1 in bark and 16.3 ng g-1 in foliage) than the conifers, namely red spruce (Picea rubens Sarg.), balsam fir (Abies balsamea (L.) Mill.) and white pine (Pinus strobus L.) (averaging 22.5 ng g-1 in bark and 28.6 ng g-1 in foliage) (p < 0.001). Yellow birch had especially high Hg in wood (2.5 ng g-1) (p < 0.001); the other species averaged 1.4 ng g-1. The Hg content of aboveground biomass, estimated from modeled tree biomass and species composition at each site, declined from the west to the east. Wood is important to Hg budgets in spite of low concentrations, because of its large mass. With the proper analytical methods, it is possible to estimate pools and fluxes of Hg in forest vegetation.
Seeing through the Canopy: Relationship between Coarse Woody Debris and Forest Structure measured by Airborne Lidar in the Brazilian Amazon

NASA Astrophysics Data System (ADS)

Scaranello, M. A., Sr.; Keller, M. M.; dos-Santos, M. N.; Longo, M.; Pinagé, E. R.; Leitold, V.

2016-12-01

Coarse woody debris is an important but infrequently quantified carbon pool in tropical forests. Based on studies at 12 sites spread across the Brazilian Amazon, we quantified coarse woody debris stocks in intact forests and forests affected by different intensities of degradation by logging and/or fire. Measurement were made in-situ and for the first time field measurements of coarse woody debris were related to structural metrics derived from airborne lidar. Using the line-intercept method we established 84 transects for sampling fallen coarse woody debris and associated inventory plots for sampling standing dead wood in intact, conventional logging, reduced impact logging, burned and burned after logging forests. Overall mean and standard deviation of total coarse woody debris were 50.0 Mg ha-1 and 26.4 Mg ha-1 respectively. Forest degradation increased coarse woody debris stocks compared to intact forests by a factor of 1.7 in reduced impact logging forests and up to 3-fold in burned forests, in a side-by-side comparison of nearby areas. The ratio between coarse woody debris and biomass increased linearly with number of degradation events (R²: 0.67, p<0.01). Individual lidar-derived structural variables strongly correlated with coarse woody debris in intact and reduced impact logging forests: the 5th percentile of last returns for in intact forests (R²: 0.78, p<0.01) and forest gap area, mapped using lidar-derived canopy height model, for reduced impact logging forests (R²: 0.63, p<0.01). Individual gap area also played a weak but significant role in determining coarse woody debris in burned forests (R2: 0.21, p<0.05), but with contrasting trend. Both degradation-specific and general multiple models using lidar-derived variables were good predictor of coarse woody debris stocks in different degradation levels in the Brazilian Amazon. The strong relation of coarse woody debris with lidar derived structural variables suggests an approach for quantifying infrequently measured coarse woody debris over large areas.
Changes in Carbon Storage and Net Carbon Exchange After a Shelterwood Harvest at Howland Forest, Maine

NASA Astrophysics Data System (ADS)

Scott, N. A.; Rodrigues, C. A.; Hughes, H.; Lee, J. T.; Davidson, E. A.; Dail, D. B.; Goltz, S. M.; Malerba, P.; Hollinger, D. Y.

2003-12-01

While many forests are actively sequestering carbon, little research has examined the direct effects of forest management practices on carbon sequestration. This is a critical issue in North America, where a large proportion of forests are managed. At the Howland Forest in Maine, we are using eddy covariance, biometric techniques and modeling to evaluate changes in carbon storage following a shelterwood cut that removed just under 30% of aboveground biomass. This management regime is becoming increasingly common throughout the region. Prior to harvest, the stand contained about 76 Mg C ha-1 (30 m2ha-1 basal area) in above- and below-ground live biomass. Harvesting removed about 15 Mg C ha-1 (SEM=2.1), and created about 5.3 Mg C ha-1 (SEM=1.1) of aboveground and 5.2 Mg C ha-1 (SEM=0.7) of root/stump detritus. Leaf-area index and litterfall declined by about 40% with harvest. Approximately half of the harvested wood was used for paper products (half-life of 3.5 years) and half for longer-lived wood products (half-life of 45 years). In a nearby, unharvested stand, eddy covariance measurements indicated that net ecosystem exchange (NEE) averages about 1.8 Mg C ha-1 y-1. A comparison of NEE at unharvested and harvested stands, both pre- and post-harvest, indicated that NEE declined following the harvest by about 18%, which is less than expected based on basal area and LAI changes. Both daily uptake and nocturnal respiration declined after harvest. Soil respiration declined slightly with harvest, suggesting no major soil C loss after harvest; harvesting had little effect on soil moisture and temperature. When decay of paper and wood products is included in a preliminary carbon budget, we predict that the forest will be a net C source to the atmosphere for at least 5 years, assuming pre-harvest growth rates of trees. How quickly the carbon balance becomes positive will depend largely on whether post-harvest tree growth rates increase.

Elevated air humidity affects hydraulic traits and tree size but not biomass allocation in young silver birches (Betula pendula)

PubMed Central

Sellin, Arne; Rosenvald, Katrin; Õunapuu-Pikas, Eele; Tullus, Arvo; Ostonen, Ivika; Lõhmus, Krista

2015-01-01

As changes in air temperature, precipitation, and air humidity are expected in the coming decades, studies on the impact of these environmental shifts on plant growth and functioning are of major importance. Greatly understudied aspects of climate change include consequences of increasing air humidity on forest ecosystems, predicted for high latitudes. The main objective of this study was to find a link between hydraulic acclimation and shifts in trees’ resource allocation in silver birch (Betula pendula Roth) in response to elevated air relative humidity (RH). A second question was whether the changes in hydraulic architecture depend on tree size. Two years of application of increased RH decreased the biomass accumulation in birch saplings, but the biomass partitioning among aboveground parts (leaves, branches, and stems) remained unaffected. Increased stem Huber values (xylem cross-sectional area to leaf area ratio) observed in trees under elevated RH did not entail changes in the ratio of non-photosynthetic to photosynthetic tissues. The reduction of stem–wood density is attributable to diminished mechanical load imposed on the stem, since humidified trees had relatively shorter crowns. Growing under higher RH caused hydraulic conductance of the root system (KR) to increase, while KR (expressed per unit leaf area) decreased and leaf hydraulic conductance increased with tree size. Saplings of silver birch acclimate to increasing air humidity by adjusting plant morphology (live crown length, slenderness, specific leaf area, and fine-root traits) and wood density rather than biomass distribution among aboveground organs. The treatment had a significant effect on several hydraulic properties of the trees, while the shifts were largely associated with changes in tree size but not in biomass allocation. PMID:26528318
Structural development of redwood branches and its effects on wood growth.

PubMed

Kramer, Russell D; Sillett, Stephen C; Carroll, Allyson L

2014-03-01

Redwood branches provide all the carbohydrates for the most carbon-heavy forests on Earth, and recent whole-tree measurements have quantified trunk growth rates associated with complete branch inventories. Providing all of a tree's photosynthetic capacity, branches represent an increasing proportion of total aboveground wood production as trees enlarge. To examine branch development and its effects on wood volume growth, we dissected 31 branches from eight Sequoia sempervirens (D. Don) Endl. and seven Sequoiadendron giganteum Lindl. trees. The cambium-area-to-leaf-area ratio was maintained with size and age but increased with light availability, whereas the heartwood-deposition-area-to-leaf-area ratio increased with size and age but was insensitive to light availability. The proportion of foliage mass arrayed in <1-cm-diameter epicormic shoots increased with decreasing light and was higher in Sequoia (20-60%) than in Sequoiadendron (3-16%). Well-illuminated branches concentrated leaves higher and distally, while shaded branches distributed leaves lower and proximally. In similar light environments, older branches distributed leaves lower and more proximally than younger branches. Branch size, light, species, heartwood area, a heartwood-area-species interaction, and ovulate cone mass predicted 87.5% of the variability in wood volume growth of branches. After accounting for the positive effects of size and light, wood volume growth declined with heartwood area and age. The effect of age was trivial compared to the effect of heartwood area, suggesting that heartwood expansion caused the age-related decline in wood volume growth. Additionally, Sequoiadendron branches of similar size and light environment with more ovulate cones produced less wood, even though these cones were long-lived and photosynthetic, reflecting the energetic cost of seed production. These results contributed to a conceptual model of branch development in which light availability, injury, heartwood content, gravity, and time interact to produce the high degree of branch structural variation evident within redwood crowns.
Louisiana’s timber industry-timber product output and use, 2013

Treesearch

James A. Gray; James W. Bentley; Jason A. Cooper; David J. Wall

2017-01-01

In 2013, processing of primary products in Louisiana mills gener-ated 206.7 million cubic feet of wood and bark residues. Coarse residues from all primary products amounted to 76.9 million cubic feet, while bark volume totaled 68.3 million cubic feet. Collective-ly, sawdust and shavings made up 30 percent of total residues, or 61.4 million cubic feet (fig. 7).
Saproxylic beetles in a Swedish boreal forest landscape managed according to 'new forestry'

Treesearch

Stig Larsson; Barbara Ekbom; L. Martin Schroeder; Melodie A. McGeoch

2006-01-01

A major threat to biodiversity in Swedish forests is the decline of Coarse Woody Debris (CWD), which is an essential resource for many organisms and plays an essential role for the structure and function of boreal forests. Removal of CWD in commercial forestry has depleted important resources for many rare wood-living (saproxylic) beetles. Replenishment of CWD has been...
Litter-dwelling arthropod abundance peaks near coarse woody debris in loblolly pine forest of the southeastern United States.

Treesearch

Michael D. Ulyshen; J.L. Hanula

2009-01-01

Several recent studies have shown that many litter-dwelling arthropod and other invertebrate taxa (e.g., Isopoda, Chilopoda, Diplopoda, Araneae, Pseudo scorpionida, Coleoptera, and Gastropoda) are more numerous near dead wood than away from it in the broad-leaved forests of Europe (Jabin et al. 2004; Topp et al. 2006a, 2006b; Kappes et...
Litter-dwelling arthropod abundance peaks near coarse woody debris in loblolly pine forests of the southeastern United States

Treesearch

Michael D. Ulyshen; James L. Hanula

2009-01-01

litter-dwelling arthropod and other invertebrate taxa (e.g., Isopoda, Chilopoda, Diplopoda, Araneae, Pseudoscorpionida, Coleoptera, and Gastropoda) are more numerous near dead wood than away from it in the broad-leaved forests of Europe(Jabin et al. 2004; Topp et al. 2006a, 2006b; Kappes et al. 2006; Kappes 2006; Jabin et al. 2007) and...
From Models to Measurements: Comparing Downed Dead Wood Carbon Stock Estimates in the U.S. Forest Inventory

Treesearch

Grant M. Domke; Christopher W. Woodall; Brian F. Walters; James E. Smith

2013-01-01

The inventory and monitoring of coarse woody debris (CWD) carbon (C) stocks is an essential component of any comprehensive National Greenhouse Gas Inventory (NGHGI). Due to the expense and difficulty associated with conducting field inventories of CWD pools, CWD C stocks are often modeled as a function of more commonly measured stand attributes such as live tree C...
N-fertilization has different effects on the growth, carbon and nitrogen physiology, and wood properties of slow- and fast-growing Populus species

PubMed Central

Luo, Zhi-Bin

2012-01-01

To investigate how N-fertilization affects the growth, carbon and nitrogen (N) physiology, and wood properties of poplars with contrasting growth characteristics, slow-growing (Populus popularis, Pp) and fast-growing (P. alba×P. glandulosa, Pg) poplar saplings were exposed to different N levels. Above-ground biomass, leaf area, photosynthetic rates (A), instantaneous photosynthetic nitrogen use efficiency (PNUE i), chlorophyll and foliar sugar concentrations were higher in Pg than in Pp. Foliar nitrate reductase (NR) activities and root glutamate synthase (GOGAT) activities were higher in Pg than in Pp as were the N amount and NUE of new shoots. Lignin contents and calorific values of Pg wood were less than that of Pp wood. N-fertilization reduced root biomass of Pg more than of Pp, but increased leaf biomass, leaf area, A, and PNUEi of Pg more than of Pp. Among 13 genes involved in the transport of ammonium or nitrate or in N assimilation, transcripts showed more pronounced changes to N-fertilization in Pg than in Pp. Increases in NR activities and N contents due to N-fertilization were larger in Pg than in Pp. In both species, N-fertilization resulted in lower calorific values as well as shorter and wider vessel elements/fibres. These results suggest that growth, carbon and N physiology, and wood properties are more sensitive to increasing N availability in fast-growing poplars than in slow-growing ones, which is probably due to prioritized resource allocation to the leaves and accelerated N physiological processes in fast-growing poplars under higher N levels. PMID:23028021
N-fertilization has different effects on the growth, carbon and nitrogen physiology, and wood properties of slow- and fast-growing Populus species.

PubMed

Li, Hong; Li, Mengchun; Luo, Jie; Cao, Xu; Qu, Long; Gai, Ying; Jiang, Xiangning; Liu, Tongxian; Bai, Hua; Janz, Dennis; Polle, Andrea; Peng, Changhui; Luo, Zhi-Bin

2012-10-01

To investigate how N-fertilization affects the growth, carbon and nitrogen (N) physiology, and wood properties of poplars with contrasting growth characteristics, slow-growing (Populus popularis, Pp) and fast-growing (P. alba×P. glandulosa, Pg) poplar saplings were exposed to different N levels. Above-ground biomass, leaf area, photosynthetic rates (A), instantaneous photosynthetic nitrogen use efficiency (PNUE (i)), chlorophyll and foliar sugar concentrations were higher in Pg than in Pp. Foliar nitrate reductase (NR) activities and root glutamate synthase (GOGAT) activities were higher in Pg than in Pp as were the N amount and NUE of new shoots. Lignin contents and calorific values of Pg wood were less than that of Pp wood. N-fertilization reduced root biomass of Pg more than of Pp, but increased leaf biomass, leaf area, A, and PNUE(i) of Pg more than of Pp. Among 13 genes involved in the transport of ammonium or nitrate or in N assimilation, transcripts showed more pronounced changes to N-fertilization in Pg than in Pp. Increases in NR activities and N contents due to N-fertilization were larger in Pg than in Pp. In both species, N-fertilization resulted in lower calorific values as well as shorter and wider vessel elements/fibres. These results suggest that growth, carbon and N physiology, and wood properties are more sensitive to increasing N availability in fast-growing poplars than in slow-growing ones, which is probably due to prioritized resource allocation to the leaves and accelerated N physiological processes in fast-growing poplars under higher N levels.
Patterns in hydraulic architecture from roots to branches in six tropical tree species from cacao agroforestry and their relation to wood density and stem growth.

PubMed

Kotowska, Martyna M; Hertel, Dietrich; Rajab, Yasmin Abou; Barus, Henry; Schuldt, Bernhard

2015-01-01

For decades it has been assumed that the largest vessels are generally found in roots and that vessel size and corresponding sapwood area-specific hydraulic conductivity are acropetally decreasing toward the distal twigs. However, recent studies from the perhumid tropics revealed a hump-shaped vessel size distribution. Worldwide tropical perhumid forests are extensively replaced by agroforestry systems often using introduced species of various biogeographical and climatic origins. Nonetheless, it is unknown so far what kind of hydraulic architectural patterns are developed in those agroforestry tree species and which impact this exerts regarding important tree functional traits, such as stem growth, hydraulic efficiency and wood density (WD). We investigated wood anatomical and hydraulic properties of the root, stem and branch wood in Theobroma cacao and five common shade tree species in agroforestry systems on Sulawesi (Indonesia); three of these were strictly perhumid tree species, and the other three tree species are tolerating seasonal drought. The overall goal of our study was to relate these properties to stem growth and other tree functional traits such as foliar nitrogen content and sapwood to leaf area ratio. Our results confirmed a hump-shaped vessel size distribution in nearly all species. Drought-adapted species showed divergent patterns of hydraulic conductivity, vessel density, and relative vessel lumen area between root, stem and branch wood compared to wet forest species. Confirming findings from natural old-growth forests in the same region, WD showed no relationship to specific conductivity. Overall, aboveground growth performance was better predicted by specific hydraulic conductivity than by foliar traits and WD. Our study results suggest that future research on conceptual trade-offs of tree hydraulic architecture should consider biogeographical patterns underlining the importance of anatomical adaptation mechanisms to environment.
Tracking downed dead wood in forests over time: Development of a piece matching algorithm for line intercept sampling

Treesearch

C.W. Woodall; B.F. Walters; J.A. Westfall

2012-01-01

Emerging questions from bioenergy policy debates have highlighted knowledge gaps regarding the carbon and biomass dynamics of individual pieces of coarse woody debris (CWD) across the diverse forest ecosystems of the US. Although there is a lack of long-term measurements of CWD across the diverse forest ecosystems of the US, there is an abundance of line intersect...
Responses of arthropods to large-scale manipulations of dead wood in loblolly pine stands of the Southeastern United States

Treesearch

Michael D. Ulyshen; James L. Hanula

2009-01-01

Large-scale experimental manipulations of deadwood are needed to better understand its importance to animal communities in managed forests. In this experiment, we compared the abundance, species richness, diversity, and composition of arthropods in 9.3-ha plots in which either (1) all coarse woody debris was removed, (2) a large number of logs were added, (3) a large...
Responses of Arthropods to large scale manipulations of dead wood in loblolly pine stands of the southeastern United States

Treesearch

Michael Ulyshen; James Hanula

2009-01-01

Large-scale experimentalmanipulations of deadwood are needed to better understand its importance to animal communities in managed forests. In this experiment, we compared the abundance, species richness, diversity, and composition of arthropods in 9.3-ha plots in which either (1) all coarse woody debris was removed, (2) a large number of logs were added, (3) a large...
DOE Office of Scientific and Technical Information (OSTI.GOV)

Handford, C.R.

Rather spotty but excellent exposures of the Cretaceous-age Turkana Grits occur near the western shore of Lake Turkana, northern Kenya. These very coarse to pebbly arkosic sandstones and sandy conglomerates were derived from and rest unconformably upon Precambrian metamorphic basement; they are overlain by late Tertiary basaltic flows that comprise much of the volcanics in the East African Rift Zone. The formation ranges up to 2000 ft thick in the Laburr Range. Several outcrops contain sauropod, crocodile, and tortoise remains as well as abundant trunks of petrified wood (Dryoxylon). Five major facies make up the Turkana Grits and record amore » major episode of continental fluvial deposition in basins flanked by Precambrian basement. Facies 1 is crudely stratified, cobble and boulder conglomerate (clast-supported); Facies 2 is crudely stratified pebble-cobble conglomerate and pebbly sandstone; Facies 3 is trough cross-bedded, very coarse sandstones containing fossils wood and vertebrate remains; Facies 4 is crudely stratified to massive sandstones with ironstone nodules; and Facies 5 is red, purple, and gray mudstone and mud shale with carbonate nodules. Facies 1 through 3 record deposition in proximal to medial braided-stream channel, longitudinal bar and dune complexes. Facies 4 is a lowland, hydromorphic paleosol, and Facies 5 represents overbank and abandoned channel-fill sedimentation in an alluvial plain.« less
Shifts in biomass and productivity for a subtropical dry forest in response to simulated elevated hurricane disturbances

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holm, Jennifer A.; Van Bloem, Skip J.; Larocque, Guy R.

Caribbean tropical forests are subject to hurricane disturbances of great variability. In addition to natural storm incongruity, climate change can alter storm formation, duration, frequency, and intensity. This model -based investigation assessed the impacts of multiple storms of different intensities and occurrence frequencies on the long-term dynamics of subtropical dry forests in Puerto Rico. Using the previously validated individual-based gap model ZELIG-TROP, we developed a new hurricane damage routine and parameterized it with site- and species-specific hurricane effects. A baseline case with the reconstructed historical hurricane regime represented the control condition. Ten treatment cases, reflecting plausible shifts in hurricane regimes,more » manipulated both hurricane return time (i.e. frequency) and hurricane intensity. The treatment-related change in carbon storage and fluxes were reported as changes in aboveground forest biomass (AGB), net primary productivity (NPP), and in the aboveground carbon partitioning components, or annual carbon accumulation (ACA). Increasing the frequency of hurricanes decreased aboveground biomass by between 5% and 39%, and increased NPP between 32% and 50%. Decadal-scale biomass fluctuations were damped relative to the control. In contrast, increasing hurricane intensity did not create a large shift in the long-term average forest structure, NPP, or ACA from that of historical hurricane regimes, but produced large fluctuations in biomass. Decreasing both the hurricane intensity and frequency by 50% produced the highest values of biomass and NPP. For the control scenario and with increased hurricane intensity, ACA was negative, which indicated that the aboveground forest components acted as a carbon source. However, with an increase in the frequency of storms or decreased storms, the total ACA was positive due to shifts in leaf production, annual litterfall, and coarse woody debris inputs, indicating a carbon sink into the forest over the long-term. The carbon loss from each hurricane event, in all scenarios, always recovered over sufficient time. Our results suggest that subtropical dry forests will remain resilient to hurricane disturbance. However carbon stocks will decrease if future climates increase hurricane frequency by 50% or more.« less
Shifts in biomass and productivity for a subtropical dry forest in response to simulated elevated hurricane disturbances

NASA Astrophysics Data System (ADS)

Holm, Jennifer A.; Van Bloem, Skip J.; Larocque, Guy R.; Shugart, Herman H.

2017-02-01

Caribbean tropical forests are subject to hurricane disturbances of great variability. In addition to natural storm incongruity, climate change can alter storm formation, duration, frequency, and intensity. This model-based investigation assessed the impacts of multiple storms of different intensities and occurrence frequencies on the long-term dynamics of subtropical dry forests in Puerto Rico. Using the previously validated individual-based gap model ZELIG-TROP, we developed a new hurricane damage routine and parameterized it with site- and species-specific hurricane effects. A baseline case with the reconstructed historical hurricane regime represented the control condition. Ten treatment cases, reflecting plausible shifts in hurricane regimes, manipulated both hurricane return time (i.e. frequency) and hurricane intensity. The treatment-related change in carbon storage and fluxes were reported as changes in aboveground forest biomass (AGB), net primary productivity (NPP), and in the aboveground carbon partitioning components, or annual carbon accumulation (ACA). Increasing the frequency of hurricanes decreased aboveground biomass by between 5% and 39%, and increased NPP between 32% and 50%. Decadal-scale biomass fluctuations were damped relative to the control. In contrast, increasing hurricane intensity did not create a large shift in the long-term average forest structure, NPP, or ACA from that of historical hurricane regimes, but produced large fluctuations in biomass. Decreasing both the hurricane intensity and frequency by 50% produced the highest values of biomass and NPP. For the control scenario and with increased hurricane intensity, ACA was negative, which indicated that the aboveground forest components acted as a carbon source. However, with an increase in the frequency of storms or decreased storms, the total ACA was positive due to shifts in leaf production, annual litterfall, and coarse woody debris inputs, indicating a carbon sink into the forest over the long-term. The carbon loss from each hurricane event, in all scenarios, always recovered over sufficient time. Our results suggest that subtropical dry forests will remain resilient to hurricane disturbance. However carbon stocks will decrease if future climates increase hurricane frequency by 50% or more.
Shifts in biomass and productivity for a subtropical dry forest in response to simulated elevated hurricane disturbances

DOE PAGES

Holm, Jennifer A.; Van Bloem, Skip J.; Larocque, Guy R.; ...

2017-02-07

Caribbean tropical forests are subject to hurricane disturbances of great variability. In addition to natural storm incongruity, climate change can alter storm formation, duration, frequency, and intensity. This model -based investigation assessed the impacts of multiple storms of different intensities and occurrence frequencies on the long-term dynamics of subtropical dry forests in Puerto Rico. Using the previously validated individual-based gap model ZELIG-TROP, we developed a new hurricane damage routine and parameterized it with site- and species-specific hurricane effects. A baseline case with the reconstructed historical hurricane regime represented the control condition. Ten treatment cases, reflecting plausible shifts in hurricane regimes,more » manipulated both hurricane return time (i.e. frequency) and hurricane intensity. The treatment-related change in carbon storage and fluxes were reported as changes in aboveground forest biomass (AGB), net primary productivity (NPP), and in the aboveground carbon partitioning components, or annual carbon accumulation (ACA). Increasing the frequency of hurricanes decreased aboveground biomass by between 5% and 39%, and increased NPP between 32% and 50%. Decadal-scale biomass fluctuations were damped relative to the control. In contrast, increasing hurricane intensity did not create a large shift in the long-term average forest structure, NPP, or ACA from that of historical hurricane regimes, but produced large fluctuations in biomass. Decreasing both the hurricane intensity and frequency by 50% produced the highest values of biomass and NPP. For the control scenario and with increased hurricane intensity, ACA was negative, which indicated that the aboveground forest components acted as a carbon source. However, with an increase in the frequency of storms or decreased storms, the total ACA was positive due to shifts in leaf production, annual litterfall, and coarse woody debris inputs, indicating a carbon sink into the forest over the long-term. The carbon loss from each hurricane event, in all scenarios, always recovered over sufficient time. Our results suggest that subtropical dry forests will remain resilient to hurricane disturbance. However carbon stocks will decrease if future climates increase hurricane frequency by 50% or more.« less
Genetic improvement of fiber length and coarseness based on paper product performance and material variability - a review

Treesearch

Brian K. Via; Michael Stine; Todd F. Shupe; Chi-Leung So; Leslie Groom

2004-01-01

Improvement of specific gravity through tree breeding was an early choice made in the mid 20th century due to its ease of measurement and impact on pulp yield and lumber strength and stiffness. This was often the first, and in many cases, the only wood quality trait selected for. However, from a product standpoint, increased specific gravity has shown to lower many...
Evaluating the effect of alternative carbon allocation schemes in a land surface model (CLM4.5) on carbon fluxes, pools, and turnover in temperate forests

NASA Astrophysics Data System (ADS)

Montané, Francesc; Fox, Andrew M.; Arellano, Avelino F.; MacBean, Natasha; Alexander, M. Ross; Dye, Alex; Bishop, Daniel A.; Trouet, Valerie; Babst, Flurin; Hessl, Amy E.; Pederson, Neil; Blanken, Peter D.; Bohrer, Gil; Gough, Christopher M.; Litvak, Marcy E.; Novick, Kimberly A.; Phillips, Richard P.; Wood, Jeffrey D.; Moore, David J. P.

2017-09-01

How carbon (C) is allocated to different plant tissues (leaves, stem, and roots) determines how long C remains in plant biomass and thus remains a central challenge for understanding the global C cycle. We used a diverse set of observations (AmeriFlux eddy covariance tower observations, biomass estimates from tree-ring data, and leaf area index (LAI) measurements) to compare C fluxes, pools, and LAI data with those predicted by a land surface model (LSM), the Community Land Model (CLM4.5). We ran CLM4.5 for nine temperate (including evergreen and deciduous) forests in North America between 1980 and 2013 using four different C allocation schemes: i. dynamic C allocation scheme (named "D-CLM4.5") with one dynamic allometric parameter, which allocates C to the stem and leaves to vary in time as a function of annual net primary production (NPP); ii. an alternative dynamic C allocation scheme (named "D-Litton"), where, similar to (i), C allocation is a dynamic function of annual NPP, but unlike (i) includes two dynamic allometric parameters involving allocation to leaves, stem, and coarse roots; iii.-iv. a fixed C allocation scheme with two variants, one representative of observations in evergreen (named "F-Evergreen") and the other of observations in deciduous forests (named "F-Deciduous"). D-CLM4.5 generally overestimated gross primary production (GPP) and ecosystem respiration, and underestimated net ecosystem exchange (NEE). In D-CLM4.5, initial aboveground biomass in 1980 was largely overestimated (between 10 527 and 12 897 g C m-2) for deciduous forests, whereas aboveground biomass accumulation through time (between 1980 and 2011) was highly underestimated (between 1222 and 7557 g C m-2) for both evergreen and deciduous sites due to a lower stem turnover rate in the sites than the one used in the model. D-CLM4.5 overestimated LAI in both evergreen and deciduous sites because the leaf C-LAI relationship in the model did not match the observed leaf C-LAI relationship at our sites. Although the four C allocation schemes gave similar results for aggregated C fluxes, they translated to important differences in long-term aboveground biomass accumulation and aboveground NPP. For deciduous forests, D-Litton gave more realistic Cstem / Cleaf ratios and strongly reduced the overestimation of initial aboveground biomass and aboveground NPP for deciduous forests by D-CLM4.5. We identified key structural and parameterization deficits that need refinement to improve the accuracy of LSMs in the near future. These include changing how C is allocated in fixed and dynamic schemes based on data from current forest syntheses and different parameterization of allocation schemes for different forest types. Our results highlight the utility of using measurements of aboveground biomass to evaluate and constrain the C allocation scheme in LSMs, and suggest that stem turnover is overestimated by CLM4.5 for these AmeriFlux sites. Understanding the controls of turnover will be critical to improving long-term C processes in LSMs.
Evaluating the effect of alternative carbon allocation schemes in a land surface model (CLM4.5) on carbon fluxes, pools, and turnover in temperate forests

DOE PAGES

Montané, Francesc; Fox, Andrew M.; Arellano, Avelino F.; ...

2017-09-22

How carbon (C) is allocated to different plant tissues (leaves, stem, and roots) determines how long C remains in plant biomass and thus remains a central challenge for understanding the global C cycle. We used a diverse set of observations (AmeriFlux eddy covariance tower observations, biomass estimates from tree-ring data, and leaf area index (LAI) measurements) to compare C fluxes, pools, and LAI data with those predicted by a land surface model (LSM), the Community Land Model (CLM4.5). We ran CLM4.5 for nine temperate (including evergreen and deciduous) forests in North America between 1980 and 2013 using four different C allocationmore » schemes: i. dynamic C allocation scheme (named "D-CLM4.5") with one dynamic allometric parameter, which allocates C to the stem and leaves to vary in time as a function of annual net primary production (NPP); ii. an alternative dynamic C allocation scheme (named "D-Litton"), where, similar to (i), C allocation is a dynamic function of annual NPP, but unlike (i) includes two dynamic allometric parameters involving allocation to leaves, stem, and coarse roots; iii.–iv. a fixed C allocation scheme with two variants, one representative of observations in evergreen (named "F-Evergreen") and the other of observations in deciduous forests (named "F-Deciduous"). D-CLM4.5 generally overestimated gross primary production (GPP) and ecosystem respiration, and underestimated net ecosystem exchange (NEE). In D-CLM4.5, initial aboveground biomass in 1980 was largely overestimated (between 10 527 and 12 897 g C m -2) for deciduous forests, whereas aboveground biomass accumulation through time (between 1980 and 2011) was highly underestimated (between 1222 and 7557 g C m -2) for both evergreen and deciduous sites due to a lower stem turnover rate in the sites than the one used in the model. D-CLM4.5 overestimated LAI in both evergreen and deciduous sites because the leaf C–LAI relationship in the model did not match the observed leaf C–LAI relationship at our sites. Although the four C allocation schemes gave similar results for aggregated C fluxes, they translated to important differences in long-term aboveground biomass accumulation and aboveground NPP. For deciduous forests, D-Litton gave more realistic C stem/C leaf ratios and strongly reduced the overestimation of initial aboveground biomass and aboveground NPP for deciduous forests by D-CLM4.5. We identified key structural and parameterization deficits that need refinement to improve the accuracy of LSMs in the near future. These include changing how C is allocated in fixed and dynamic schemes based on data from current forest syntheses and different parameterization of allocation schemes for different forest types. Our results highlight the utility of using measurements of aboveground biomass to evaluate and constrain the C allocation scheme in LSMs, and suggest that stem turnover is overestimated by CLM4.5 for these AmeriFlux sites. Understanding the controls of turnover will be critical to improving long-term C processes in LSMs.« less

Evaluating the effect of alternative carbon allocation schemes in a land surface model (CLM4.5) on carbon fluxes, pools, and turnover in temperate forests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montané, Francesc; Fox, Andrew M.; Arellano, Avelino F.

How carbon (C) is allocated to different plant tissues (leaves, stem, and roots) determines how long C remains in plant biomass and thus remains a central challenge for understanding the global C cycle. We used a diverse set of observations (AmeriFlux eddy covariance tower observations, biomass estimates from tree-ring data, and leaf area index (LAI) measurements) to compare C fluxes, pools, and LAI data with those predicted by a land surface model (LSM), the Community Land Model (CLM4.5). We ran CLM4.5 for nine temperate (including evergreen and deciduous) forests in North America between 1980 and 2013 using four different C allocationmore » schemes: i. dynamic C allocation scheme (named "D-CLM4.5") with one dynamic allometric parameter, which allocates C to the stem and leaves to vary in time as a function of annual net primary production (NPP); ii. an alternative dynamic C allocation scheme (named "D-Litton"), where, similar to (i), C allocation is a dynamic function of annual NPP, but unlike (i) includes two dynamic allometric parameters involving allocation to leaves, stem, and coarse roots; iii.–iv. a fixed C allocation scheme with two variants, one representative of observations in evergreen (named "F-Evergreen") and the other of observations in deciduous forests (named "F-Deciduous"). D-CLM4.5 generally overestimated gross primary production (GPP) and ecosystem respiration, and underestimated net ecosystem exchange (NEE). In D-CLM4.5, initial aboveground biomass in 1980 was largely overestimated (between 10 527 and 12 897 g C m -2) for deciduous forests, whereas aboveground biomass accumulation through time (between 1980 and 2011) was highly underestimated (between 1222 and 7557 g C m -2) for both evergreen and deciduous sites due to a lower stem turnover rate in the sites than the one used in the model. D-CLM4.5 overestimated LAI in both evergreen and deciduous sites because the leaf C–LAI relationship in the model did not match the observed leaf C–LAI relationship at our sites. Although the four C allocation schemes gave similar results for aggregated C fluxes, they translated to important differences in long-term aboveground biomass accumulation and aboveground NPP. For deciduous forests, D-Litton gave more realistic C stem/C leaf ratios and strongly reduced the overestimation of initial aboveground biomass and aboveground NPP for deciduous forests by D-CLM4.5. We identified key structural and parameterization deficits that need refinement to improve the accuracy of LSMs in the near future. These include changing how C is allocated in fixed and dynamic schemes based on data from current forest syntheses and different parameterization of allocation schemes for different forest types. Our results highlight the utility of using measurements of aboveground biomass to evaluate and constrain the C allocation scheme in LSMs, and suggest that stem turnover is overestimated by CLM4.5 for these AmeriFlux sites. Understanding the controls of turnover will be critical to improving long-term C processes in LSMs.« less
The radiocesium dynamics in the Fukushima forests at the late stage after deposition

NASA Astrophysics Data System (ADS)

Yoschenko, Vasyl; Takase, Tsugiko; Nanba, Kenji; Konoplev, Alexei; Onda, Yuichi

2017-04-01

Forests cover about 2/3 of the territory of Areas 2 and 3 in the Fukushima prefecture. This territory was heavily contaminated with radiocesium released from the Fukushima Dai-Ichi Nuclear Power Plant in March 2011. The extensive decontamination measures aimed to prepare the return of population have been scheduled and are being implemented at the agricultural and residential lands at this territory. However, these measures will be not applied in the large scale in the Fukushima forests. The current radiocesium levels in wood at this territory exceed the Japanese standards for wood; thus, after return of population, the Fukushima forests may remain excluded from the economical use. Understanding of the further dynamics of radiocesium in the forest ecosystems is necessary for elaboration of the strategy concerning the radioactive contaminated Fukushima forests. In March 2011 radiocesium was intercepted by the tree canopies and then, at the early stage after the accident, was effectively transported to the soil surface with precipitation and litterfall, and partly translocated to wood forming the current levels. The general trend was the decrease of the radiocesium inventory in the aboveground forest biomass. After redistribution in the root-inhabited soil layer radiocesium became available for uptake into the trees through the roots. From the Chernobyl experience, the further levels of radiocesium in the forest ecosystem compartments at the late stage may increase or decrease depending on the intensities of the root uptake and removal fluxes. In the Fukushima forests, the stage of the root uptake has begun recently, and the parameters of the root uptake have not been studied well for the varieties of species, forest types and soil conditions. Our study is aimed to monitoring and modelling of the radiocesium redistribution in the Fukushima forests after the removal of its initial deposition from the tree canopies. The study has been performed since May 2014 at several experimental sites in the typical Fukushima forests (Japanese cedar, Japanese red pine). We observe the dynamics of the radiocesium concentrations and total inventories in the ecosystem compartments and quantify the biogenic fluxes of radiocesium which will determine its further redistribution between the biomass, soil and litter. Our study also includes characterization of the stable cesium distributions in the forest ecosystems and development of the methods for non-destructive monitoring of the radiocesium concentration in wood. We present the observation results for the period of 2014-2016 (annual and seasonal changes in the aboveground biomass, leaching from the forest litter, downward migration in soil), as well as the estimates of the radiocesium fluxes which will be used later for the modelling of its long-term dynamics in the Fukushima forests.
Habitat selection by juvenile Swainson’s thrushes (Catharus ustulatus) in headwater riparian areas, northwestern Oregon, USA

USGS Publications Warehouse

Jenkins, Stephanie R.; Betts, Matthew G.; Huso, Manuela M.; Hagar, Joan C.

2013-01-01

Lower order, non-fish-bearing streams, often termed “headwater streams”, have received minimal research effort and protection priority, especially in mesic forests where distinction between riparian and upland vegetation can be subtle. Though it is generally thought that breeding bird abundance is higher in riparian zones, little is known about species distributions when birds are in their juvenile stage – a critical period in terms of population viability. Using radio telemetry, we examined factors affecting habitat selection by juvenile Swainson’s thrushes during the post-breeding period in headwater basins in the Coast Range of Oregon, USA. We tested models containing variables expected to influence the amount of food and cover (i.e., deciduous cover, coarse wood volume, and proximity to stream) as well as models containing variables that are frequently measured and manipulated in forest management (i.e., deciduous and coniferous trees separated into size classes). Juvenile Swainson’s thrushes were more likely to select locations with at least 25% cover of deciduous, mid-story vegetation and more than 2.0 m3/ha of coarse wood within 40 m of headwater streams. We conclude that despite their small and intermittent nature, headwater streams and adjacent riparian areas are selected over upland areas by Swainson’s thrush during the postfledging period in the Oregon Coast Range.
Selective logging: does the imprint remain on tree structure and composition after 45 years?

PubMed

Osazuwa-Peters, Oyomoare L; Chapman, Colin A; Zanne, Amy E

2015-01-01

Selective logging of tropical forests is increasing in extent and intensity. The duration over which impacts of selective logging persist, however, remains an unresolved question, particularly for African forests. Here, we investigate the extent to which a past selective logging event continues to leave its imprint on different components of an East African forest 45 years later. We inventoried 2358 stems ≥10 cm in diameter in 26 plots (200 m × 10 m) within a 5.2 ha area in Kibale National Park, Uganda, in logged and unlogged forest. In these surveys, we characterized the forest light environment, taxonomic composition, functional trait composition using three traits (wood density, maximum height and maximum diameter) and forest structure based on three measures (stem density, total basal area and total above-ground biomass). In comparison to unlogged forests, selectively logged forest plots in Kibale National Park on average had higher light levels, different structure characterized by lower stem density, lower total basal area and lower above-ground biomass, and a distinct taxonomic composition driven primarily by changes in the relative abundance of species. Conversely, selectively logged forest plots were like unlogged plots in functional composition, having similar community-weighted mean values for wood density, maximum height and maximum diameter. This similarity in functional composition irrespective of logging history may be due to functional recovery of logged forest or background changes in functional attributes of unlogged forest. Despite the passage of 45 years, the legacy of selective logging on the tree community in Kibale National Park is still evident, as indicated by distinct taxonomic and structural composition and reduced carbon storage in logged forest compared with unlogged forest. The effects of selective logging are exerted via influences on tree demography rather than functional trait composition.
Selective logging: does the imprint remain on tree structure and composition after 45 years?

PubMed Central

Osazuwa-Peters, Oyomoare L.; Chapman, Colin A.; Zanne, Amy E.

2015-01-01

Selective logging of tropical forests is increasing in extent and intensity. The duration over which impacts of selective logging persist, however, remains an unresolved question, particularly for African forests. Here, we investigate the extent to which a past selective logging event continues to leave its imprint on different components of an East African forest 45 years later. We inventoried 2358 stems ≥10 cm in diameter in 26 plots (200 m × 10 m) within a 5.2 ha area in Kibale National Park, Uganda, in logged and unlogged forest. In these surveys, we characterized the forest light environment, taxonomic composition, functional trait composition using three traits (wood density, maximum height and maximum diameter) and forest structure based on three measures (stem density, total basal area and total above-ground biomass). In comparison to unlogged forests, selectively logged forest plots in Kibale National Park on average had higher light levels, different structure characterized by lower stem density, lower total basal area and lower above-ground biomass, and a distinct taxonomic composition driven primarily by changes in the relative abundance of species. Conversely, selectively logged forest plots were like unlogged plots in functional composition, having similar community-weighted mean values for wood density, maximum height and maximum diameter. This similarity in functional composition irrespective of logging history may be due to functional recovery of logged forest or background changes in functional attributes of unlogged forest. Despite the passage of 45 years, the legacy of selective logging on the tree community in Kibale National Park is still evident, as indicated by distinct taxonomic and structural composition and reduced carbon storage in logged forest compared with unlogged forest. The effects of selective logging are exerted via influences on tree demography rather than functional trait composition. PMID:27293697
Growth maximization trumps maintenance of leaf conductance in the tallest angiosperm.

PubMed

Koch, George W; Sillett, Stephen C; Antoine, Marie E; Williams, Cameron B

2015-02-01

Structural and physiological changes that occur as trees grow taller are associated with increased hydraulic constraints on leaf gas exchange, yet it is unclear if leaf-level constraints influence whole-tree growth as trees approach their maximum size. We examined variation in leaf physiology, leaf area to sapwood area ratio (L/S), and annual aboveground growth across a range of tree heights in Eucalyptus regnans. Leaf photosynthetic capacity did not differ among upper crown leaves of individuals 61.1-92.4 m tall. Maximum daily and integrated diurnal stomatal conductance (g s) averaged 36 and 34% higher, respectively, in upper crown leaves of ~60-m-tall, 80-year-old trees than in ~90-m-tall, 300-year-old trees, with larger differences observed on days with a high vapor pressure deficit (VPD). Greater stomatal regulation in taller trees resulted in similar minimum daily leaf water potentials (Ψ L) in shorter and taller trees over a broad range of VPDs. The long-term stomatal limitation on photosynthesis, as inferred from leaf δ (13)C composition, was also greater in taller trees. The δ (13)C of wood indicated that the bulk of photosynthesis used to fuel wood production in the main trunk and branches occurred in the upper crown. L/S increased with tree height, especially after accounting for size-independent variation in crown structure across 27 trees up to 99.8 m tall. Despite greater stomatal limitation of leaf photosynthesis in taller trees, total L explained 95% of the variation in annual aboveground biomass growth among 15 trees measured for annual biomass growth increment in 2006. Our results support a theoretical model proposing that, in the face of increasing hydraulic constraints with height, whole-tree growth is maximized by a resource trade-off that increases L to maximize light capture rather than by reducing L/S to sustain g s.
Modelling basin-wide variations in Amazon forest photosynthesis

NASA Astrophysics Data System (ADS)

Mercado, Lina; Lloyd, Jon; Domingues, Tomas; Fyllas, Nikolaos; Patino, Sandra; Dolman, Han; Sitch, Stephen

2010-05-01

Given the importance of Amazon rainforest in the global carbon and hydrological cycles, there is a need to use parameterized and validated ecosystem gas exchange and vegetation models for this region in order to adequately simulate present and future carbon and water balances. Recent research has found major differences in above-ground net primary productivity (ANPP), above ground biomass and tree dynamics across Amazonia. West Amazonia is more dynamic, with younger trees, higher stem growth rates and lower biomass than central and eastern Amazon (Baker et al. 2004; Malhi et al. 2004; Phillips et al. 2004). A factor of three variation in above-ground net primary productivity has been estimated across Amazonia by Malhi et al. (2004). Different hypotheses have been proposed to explain the observed spatial variability in ANPP (Malhi et al. 2004). First, due to the proximity to the Andes, sites from western Amazonia tend to have richer soils than central and eastern Amazon and therefore soil fertility could possibly be highly related to the high wood productivity found in western sites. Second, if GPP does not vary across the Amazon basin then different patterns of carbon allocation to respiration could also explain the observed ANPP gradient. However since plant growth depends on the interaction between photosynthesis, transport of assimilates, plant respiration, water relations and mineral nutrition, variations in plant gross photosynthesis (GPP) could also explain the observed variations in ANPP. In this study we investigate whether Amazon GPP can explain variations of observed ANPP. We use a sun and shade canopy gas exchange model that has been calibrated and evaluated at five rainforest sites (Mercado et al. 2009) to simulate gross primary productivity of 50 sites across the Amazon basin during the period 1980-2001. Such simulation differs from the ones performed with global vegetation models (Cox et al. 1998; Sitch et al. 2003) where i) single plant functional type parameter values are assigned and assumed invariant with environmental condition but also ii) these models use leaf N as a factor that limit photosynthesis. Instead, since leaf P may also limit photosynthesis of the tropical forest (Reich et al. 2009), we use a more specific description of photosynthetic capacity across the basin based on the model evaluation done in Mercado et al. (2009) in which canopy photosynthetic capacity is related to foliar P but also using the relationships derived between canopy photosynthesis and leaf nutrients (N and P) from measurements in tropical trees (Domingues et al.In review). A study of this kind can inform the global vegetation/climate community as to the need for variability in key model parameters in order to accurately simulate carbon fluxes across the Amazon basin. Baker, T. R., et al. 2004. Increasing biomass in Amazonian forest plots. Philosophical Transactions of the Royal Society of London Series B-Biological Sciences 359 (1443):353-365. Phillips, O. L. et al. 2004. Pattern and process in Amazon tree turnover, 1976-2001. Philosophical Transactions of the Royal Society of London Series B-Biological Sciences 359 (1443):381-407. Malhi, Y. et al. 2004. The above-ground coarse wood productivity of 104 Neotropical forest plots. Global Change Biology 10 (5):563-591. Mercado, L.M. et al. 2009. Impact of changes in diffuse radiation on the global land carbon sink. Nature 458 (7241), 1014. Cox, P. M. et al. 1998. A canopy conductance and photosynthesis model for use in a GCM land surface scheme. Journal of Hydrology 213 (1-4):79-9 Sitch, S. et al. 2003. Evaluation of ecosystem dynamics, plant geography and terrestrial carbon cycling in the LPJ dynamic global vegetation model. Global Change Biology 9 (2):161-185. Reich B. R. et al. 2009. Leaf phosphorus influences the photosynhtesis-nitrogen relation: a cross-biome analysis of 314 species. Oecologia, doi 10.1007/s00442-009-1291-3. Domingues, T. et al. In review. Co-limitation of photosynthetic capacity by nitrogen and phosphorus along a precipitation gradient in West Africa. Plant Cell and Environment.
Dispersal limitation induces long-term biomass collapse in overhunted Amazonian forests.

PubMed

Peres, Carlos A; Emilio, Thaise; Schietti, Juliana; Desmoulière, Sylvain J M; Levi, Taal

2016-01-26

Tropical forests are the global cornerstone of biological diversity, and store 55% of the forest carbon stock globally, yet sustained provisioning of these forest ecosystem services may be threatened by hunting-induced extinctions of plant-animal mutualisms that maintain long-term forest dynamics. Large-bodied Atelinae primates and tapirs in particular offer nonredundant seed-dispersal services for many large-seeded Neotropical tree species, which on average have higher wood density than smaller-seeded and wind-dispersed trees. We used field data and models to project the spatial impact of hunting on large primates by ∼ 1 million rural households throughout the Brazilian Amazon. We then used a unique baseline dataset on 2,345 1-ha tree plots arrayed across the Brazilian Amazon to model changes in aboveground forest biomass under different scenarios of hunting-induced large-bodied frugivore extirpation. We project that defaunation of the most harvest-sensitive species will lead to losses in aboveground biomass of between 2.5-5.8% on average, with some losses as high as 26.5-37.8%. These findings highlight an urgent need to manage the sustainability of game hunting in both protected and unprotected tropical forests, and place full biodiversity integrity, including populations of large frugivorous vertebrates, firmly in the agenda of reducing emissions from deforestation and forest degradation (REDD+) programs.
Changes in cadmium mobility during composting and after soil application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanc, Ales; Tlustos, Pavel; Szakova, Jirina

2009-08-15

The effect of twelve weeks of composting on the mobility and bioavailability of cadmium in six composts containing sewage sludge, wood chips and grass was studied, along with the cadmium immobilization capacity of compost. Two different soils were used and Cd accumulation measured in above-ground oat biomass (Avena sativa L.). Increasing pH appears to be an important cause of the observed decreases in available cadmium through the composting process. A pot experiment was performed with two different amounts of compost (9.6 and 28.8 g per kg of soil) added into Fluvisol with total Cd 0.255 mg kg{sup -1}, and contaminatedmore » Cambisol with total Cd 6.16 mg kg{sup -1}. Decrease of extractable Cd (0.01 mol l{sup -1} CaCl{sub 2}) was found in both soils after compost application. The higher amount of compost immobilized an exchangeable portion of Cd (0.11 mol l{sup -1} CH{sub 3}COOH extractable) in contaminated Cambisol unlike in light Fluvisol. The addition of a low amount of compost decreased the content of Cd in associated above-ground oat biomass grown in both soils, while a high amount of compost decreased the Cd content in oats only in the Cambisol.« less
Predicting of biomass in Brazilian tropical dry forest: a statistical evaluation of generic equations.

PubMed

Lima, Robson B DE; Alves, Francisco T; Oliveira, Cinthia P DE; Silva, José A A DA; Ferreira, Rinaldo L C

2017-01-01

Dry tropical forests are a key component in the global carbon cycle and their biomass estimates depend almost exclusively of fitted equations for multi-species or individual species data. Therefore, a systematic evaluation of statistical models through validation of estimates of aboveground biomass stocks is justifiable. In this study was analyzed the capacity of generic and specific equations obtained from different locations in Mexico and Brazil, to estimate aboveground biomass at multi-species levels and for four different species. Generic equations developed in Mexico and Brazil performed better in estimating tree biomass for multi-species data. For Poincianella bracteosa and Mimosa ophthalmocentra, only the Sampaio and Silva (2005) generic equation was the most recommended. These equations indicate lower tendency and lower bias, and biomass estimates for these equations are similar. For the species Mimosa tenuiflora, Aspidosperma pyrifolium and for the genus Croton the specific regional equations are more recommended, although the generic equation of Sampaio and Silva (2005) is not discarded for biomass estimates. Models considering gender, families, successional groups, climatic variables and wood specific gravity should be adjusted, tested and the resulting equations should be validated at both local and regional levels as well as on the scales of tropics with dry forest dominance.
Selective-placement burial of drilling fluids: 2. Effects on buffalograss and fourwing saltbrush. [Atriplex canescens; Buchloe dactyloides

DOE Office of Scientific and Technical Information (OSTI.GOV)

McFarland, M.L.; Hartmann, S.; Ueckert, D.N.

Surface disposal of spent drilling fluids used in petroleum and natural gas exploration causes surface soil contamination that severely inhibits secondary plant succession and artificial revegetation efforts. Selective-placement burial was evaluated at two locations in western Texas for on-site disposal of drilling fluids in arid and semiarid regions. Establishment, yield, and chemical composition of fourwing saltbrush (Atriplex canescens (Pursh Nutt.)) and buffalograss (Buchloe dactyloides (Nutt.) Engelm.) transplants on undisturbed soils and on plots with spent drilling fluids and cuttings buried 30, 90 (with and without a 30-cm coarse limestone capillary barrier) and 150 cm were compared. Survival of both speciesmore » was 97 to 100% 17 months after planting on plots with buried drilling wastes. Canopy cover and aboveground biomass of fourwing saltbrush were greater over buried drilling wastes than on untreated plots, whereas canopy cover and aboveground biomass of buffalograss were not affected by the treatments. Significant increases in Na, M, and Mg concentrations in buffalograss after 17 months on plots with drilling fluids buried 30 cm deep at one location indicated plant uptake of some drilling fluid constituents. Elevated Zn concentrations in fourwing saltbush indicated that a portion of the Zn in the drilling fluids was available for plant uptake, while no evidence of plant accumulation of Ba, Cr, Cu, or Ni from drilling fluids was detected.« less
Effects of soil conditions on survival and growth of black willow cuttings.

PubMed

Schaff, Steven D; Pezeshki, S Reza; Shields, F Douglas

2003-06-01

Current streambank restoration efforts focus on providing bank stability, enhancing water quality, and improving woody habitat using native vegetation rather than traditional engineering techniques. However, in most cases harsh site conditions limit restoration success. A two-year field study was conducted at Twentymile Creek, in northern Mississippi, investigating edaphic factors governing the survival of black willow (Salix nigra) cuttings used for streambank restoration. Low height growth, above-ground biomass production, and average leaf area were observed in willow cuttings grown in plots subjected to moisture deficits. However, sediment texture emerged as the dominant factor determining willow post growth, health, and survival. Shoot biomass, leaf biomass, and total above-ground biomass were 15-, 10-, and 14-fold greater for large willow cuttings (posts) grown in plots with sandy sediments relative to those grown in plots with similar moisture and soil redox potential but with silt and clay sediments. Average leaf size, average leaf mass and specific leaf area were all lower in fine textured plots. Under moisture conditions present at our sites, coarse-grained sediment (sand) was more conducive to willow growth, biomass production, and survival than were fine-grained sediments (silt/clay). Our results strongly suggest that soil texture and moisture conditions can determine restoration success. Therefore, it is critical that site conditions are factored into the selection of project locations prior to the initiation of willow planting restoration projects.
Patterns in hydraulic architecture from roots to branches in six tropical tree species from cacao agroforestry and their relation to wood density and stem growth

PubMed Central

Kotowska, Martyna M.; Hertel, Dietrich; Rajab, Yasmin Abou; Barus, Henry; Schuldt, Bernhard

2015-01-01

For decades it has been assumed that the largest vessels are generally found in roots and that vessel size and corresponding sapwood area-specific hydraulic conductivity are acropetally decreasing toward the distal twigs. However, recent studies from the perhumid tropics revealed a hump-shaped vessel size distribution. Worldwide tropical perhumid forests are extensively replaced by agroforestry systems often using introduced species of various biogeographical and climatic origins. Nonetheless, it is unknown so far what kind of hydraulic architectural patterns are developed in those agroforestry tree species and which impact this exerts regarding important tree functional traits, such as stem growth, hydraulic efficiency and wood density (WD). We investigated wood anatomical and hydraulic properties of the root, stem and branch wood in Theobroma cacao and five common shade tree species in agroforestry systems on Sulawesi (Indonesia); three of these were strictly perhumid tree species, and the other three tree species are tolerating seasonal drought. The overall goal of our study was to relate these properties to stem growth and other tree functional traits such as foliar nitrogen content and sapwood to leaf area ratio. Our results confirmed a hump-shaped vessel size distribution in nearly all species. Drought-adapted species showed divergent patterns of hydraulic conductivity, vessel density, and relative vessel lumen area between root, stem and branch wood compared to wet forest species. Confirming findings from natural old-growth forests in the same region, WD showed no relationship to specific conductivity. Overall, aboveground growth performance was better predicted by specific hydraulic conductivity than by foliar traits and WD. Our study results suggest that future research on conceptual trade-offs of tree hydraulic architecture should consider biogeographical patterns underlining the importance of anatomical adaptation mechanisms to environment. PMID:25873922
Replicated throughfall exclusion experiment in an Indonesian perhumid rainforest: wood production, litter fall and fine root growth under simulated drought.

PubMed

Moser, Gerald; Schuldt, Bernhard; Hertel, Dietrich; Horna, Viviana; Coners, Heinz; Barus, Henry; Leuschner, Christoph

2014-05-01

Climate change scenarios predict increases in the frequency and duration of ENSO-related droughts for parts of South-East Asia until the end of this century exposing the remaining rainforests to increasing drought risk. A pan-tropical review of recorded drought-related tree mortalities in more than 100 monitoring plots before, during and after drought events suggested a higher drought-vulnerability of trees in South-East Asian than in Amazonian forests. Here, we present the results of a replicated (n = 3 plots) throughfall exclusion experiment in a perhumid tropical rainforest in Sulawesi, Indonesia. In this first large-scale roof experiment outside semihumid eastern Amazonia, 60% of the throughfall was displaced during the first 8 months and 80% during the subsequent 17 months, exposing the forest to severe soil desiccation for about 17 months. In the experiment's second year, wood production decreased on average by 40% with largely different responses of the tree families (ranging from -100 to +100% change). Most sensitive were trees with high radial growth rates under moist conditions. In contrast, tree height was only a secondary factor and wood specific gravity had no influence on growth sensitivity. Fine root biomass was reduced by 35% after 25 months of soil desiccation while fine root necromass increased by 250% indicating elevated fine root mortality. Cumulative aboveground litter production was not significantly reduced in this period. The trees from this Indonesian perhumid rainforest revealed similar responses of wood and litter production and root dynamics as those in two semihumid Amazonian forests subjected to experimental drought. We conclude that trees from paleo- or neotropical forests growing in semihumid or perhumid climates may not differ systematically in their growth sensitivity and vitality under sublethal drought stress. Drought vulnerability may depend more on stem cambial activity in moist periods than on tree height or wood specific gravity. © 2013 John Wiley & Sons Ltd.
Grassland Degradation Alters Soil Carbon Turnover through Depth

NASA Astrophysics Data System (ADS)

Creamer, C.; Prober, S. M.; Chappell, A.; Farrell, M.; Baldock, J.

2015-12-01

Ecosystem degradation is widespread and changes in aboveground plant communities alter belowground soil processes. In Australia, grassy eucalyptus woodlands dominated by kangaroo grasses (Themeda trianda) were widely cleared during European settlement for agriculture, with only fragments remaining of this now threatened ecosystem. As remnant grassland fragments are used for livestock grazing, Themeda transitions through states of degradation, starting with red grasses (Bothriochloa spp) and then proceeding to less productive, increasingly degraded states dominated by either annual exotic weeds or native wallaby grasses (Rytidosperma spp) and spear grasses (Austrastipa spp). The aim of our experiment was to determine how soil organic matter dynamics (including erosion, root biomass, C storage and turnover) have been altered by the transition from deeply-rooted Themeda grass systems to more shallowly-rooted annual exotic weeds and wallaby/spear grass states. We sampled soils in five depth-based increments (0-5, 5-15, 15-30, 30-60, 60-100 cm) across this ecosystem transition at five sites across New South Wales, Australia. Caseium-137 analysis indicated erosion rates were similar among all ecosystems and were consistent with levels for grasslands in the region. Compared to the remnant Themeda grass systems, the degraded states had lower root biomass, lower carbon stocks and C:N ratios in the coarse fraction (> 50 μm), lower fungal : bacterial ratios, higher available phosphate, higher alkyl : O-alkyl C ratios, and faster mineralization of synthetic root-exudate carbon. All these metrics indicate the surprising finding of more microbially processed OM and faster turnover of newly added C in the degraded sites. Compared to one another, the two degraded sites differed in both C and N turnover, with the exotic weeds having higher dissolved organic N, inorganic N, and coarse fraction N, higher fine fraction C stocks, and greater microbial biomass. These differences likely arise from the greater aboveground productivity of exotic weeds relative to the wallaby and spear grasses. Although microbial C turnover through depth is altered with grassland degradation in both states, the trajectory of the soil organic matter dynamics with degradation is also impacted by plant community dynamics.
Response of “Alamo” switchgrass tissue chemistry and biomass to nitrogen fertilization in West Tennessee, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garten, Charles T.; Brice, Deanne J.; Castro, Hector F.

2011-01-01

Switchgrass (Panicum virgatum) is a perennial, warm-season grass that has been identified as a potential biofuel feedstock over a large part of North America. We examined above- and belowground responses to nitrogen fertilization in “Alamo” switchgrass grown in West Tennessee, USA. The fertilizer study included a spring and fall sampling of 5-year old switchgrass grown under annual applications of 0, 67, and 202 kg N ha -1 (as ammonium nitrate). Fertilization changed switchgrass biomass allocation as indicated by root:shoot ratios. End-of-growing season root:shoot ratios (mean ± SE) declined significantly (P ≤ 0.05) at the highest fertilizer nitrogen treatment (2.16 ±more » 0.08, 2.02 ± 0.18, and 0.88 ± 0.14, respectively, at 0, 67, and 202 kg N ha -1). Fertilization also significantly increased above- and belowground nitrogen concentrations and decreased plant C:N ratios. Data are presented for coarse live roots, fine live roots, coarse dead roots, fine dead roots, and rhizomes. At the end of the growing season, there was more carbon and nitrogen stored in belowground biomass than aboveground biomass. Finally, fertilization impacted switchgrass tissue chemistry and biomass allocation in ways that potentially impact soil carbon cycle processes and soil carbon storage.« less
Does the presence of large down wood at the time of a forest fire impact soil recovery?

DOE PAGES

Smith, Jane E.; Kluber, Laurel A.; Jennings, Tara N.; ...

2017-02-23

Fire may remove or create dead wood aboveground, but it is less clear how high severity burning of soils affects belowground microbial communities and soil processes, and for how long. Here, we investigated soil fungal and bacterial communities and biogeochemical responses of severely burned red soil and less severely burned black soil from a burned forest on the eastern slope of the Cascade Range in Oregon. We examined the effects of burn severity on soil nutrients and microbial communi- ties for 14 years after wildfire. Soil nutrients were significantly reduced in red soils. Soil fungi and bac teria, assessed withmore » molecular methods, steadily colonized both burn severities and soil biodiversity increased throughout the study showing that microbial communities seem to have the capacity to quickly adjust to extreme disturbances. Although richness did not vary by soil type, the fungal and bacterial community compositions varied with burn severity. This difference was greatest in the early time points following the fire and decreased with time. But, nutrient-limited conditions of red soils were detected for four years after the wildfire and raise concern about soil productivity at these sites.« less
Does the presence of large down wood at the time of a forest fire impact soil recovery?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Jane E.; Kluber, Laurel A.; Jennings, Tara N.

Fire may remove or create dead wood aboveground, but it is less clear how high severity burning of soils affects belowground microbial communities and soil processes, and for how long. Here, we investigated soil fungal and bacterial communities and biogeochemical responses of severely burned red soil and less severely burned black soil from a burned forest on the eastern slope of the Cascade Range in Oregon. We examined the effects of burn severity on soil nutrients and microbial communi- ties for 14 years after wildfire. Soil nutrients were significantly reduced in red soils. Soil fungi and bac teria, assessed withmore » molecular methods, steadily colonized both burn severities and soil biodiversity increased throughout the study showing that microbial communities seem to have the capacity to quickly adjust to extreme disturbances. Although richness did not vary by soil type, the fungal and bacterial community compositions varied with burn severity. This difference was greatest in the early time points following the fire and decreased with time. But, nutrient-limited conditions of red soils were detected for four years after the wildfire and raise concern about soil productivity at these sites.« less
Forest biomass and energy-wood potential in the southern United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saucier, J.R.

1993-12-31

Timber resource data were compiled from the most recent USDA Forest Service inventory data for the 12 Southern States from Virginia to Texas. Timber resource inventories traditionally include only trees 5 inches dbh and greater and their volumes to the prevailing merchantable top diameter expressed in cubic feet, board feet, or cords. For this paper, conversion factors were developed to express timber inventories in weight and to expand the inventories to include the crowns of merchantable trees and trees less than 5 inches dbh. By so doing, the total aboveground biomass is estimated for the timberlands in the South. Themore » region contains 185 million acres of timberland. Some 14.6 billion green tons of woody biomass are present on southern timberland -- about 79 tons per acre. When mature stands are harvested, the average acre in the South has 22.2 tons of woody material left in crowns and sapling, and 5.1 tons in cull stems. Thus, an average of 27.3 green tons per acre of potential energy wood are left after conventional harvests. Conversion factors that are presented permit estimates for specific tracts, areas, counties, or states.« less
Habitat alteration increases invasive fire ant abundance to the detriment of amphibians and reptiles

USGS Publications Warehouse

Todd, B.D.; Rothermel, B.B.; Reed, R.N.; Luhring, T.M.; Schlatter, K.; Trenkamp, L.; Gibbons, J.W.

2008-01-01

Altered habitats have been suggested to facilitate red imported fire ant (Solenopsis invicta) colonization and dispersal, possibly compounding effects of habitat alteration on native wildlife. In this study, we compared colonization intensity of wood cover boards by S. invicta among four forest management treatments in South Carolina, USA: an unharvested control (>30 years old); a partially thinned stand; a clearcut with coarse woody debris retained; and a clearcut with coarse woody debris removed. Additionally, we compared dehydration rates and survival of recently metamorphosed salamanders (marbled salamanders, Ambystoma opacum, and mole salamanders, A. talpoideum) among treatments. We found that the number of wood cover boards colonized by S. invicta differed significantly among treatments, being lowest in the unharvested forest treatments and increasing with the degree of habitat alteration. Salamanders that were maintained in experimental field enclosures to study water loss were unexpectedly subjected to high levels of S. invicta predation that differed among forest treatments. All known predation by S. invicta was restricted to salamanders in clearcuts. The amount of vegetative ground cover was inversely related to the likelihood of S. invicta predation of salamanders. Our results show that S. invicta abundance increases with habitat disturbance and that this increased abundance has negative consequences for amphibians that remain in altered habitats. Our findings also suggest that the presence of invasive S. invicta may compromise the utility of cover boards and other techniques commonly used in herpetological studies in the Southeast. ?? 2007 Springer Science+Business Media B.V.

Successional changes in live and dead wood carbon stores: implications for net ecosystem productivity.

PubMed

Janisch, J E; Harmon, M E

2002-02-01

If forests are to be used in CO2 mitigation projects, it is essential to understand and quantify the impacts of disturbance on net ecosystem productivity (NEP; i.e., the change in ecosystem carbon (C) storage with time). We examined the influence of live tree and coarse woody debris (CWD) on NEP during secondary succession based on data collected along a 500-year chronosequence on the Wind River Ranger District, Washington. We developed a simple statistical model of live and dead wood accumulation and decomposition to predict changes in the woody component of NEP, which we call NEP(w). The transition from negative to positive NEP(w), for a series of scenarios in which none to all wood was left after disturbance, occurred between 0 and 57 years after disturbance. The timing of this transition decreased as live-tree growth rates increased, and increased as CWD left after disturbance increased. Maximum and minimum NEP(w) for all scenarios were 3.9 and -14.1 Mg C ha-1 year-1, respectively. Maximum live and total wood C stores of 319 and 393 Mg C ha(-1), respectively, were reached approximately 200 years after disturbance. Decomposition rates (k) of CWD ranged between 0.013 and 0.043 year-1 for individual stands. Regenerating stands took 41 years to attain a mean live wood mass equivalent to the mean mass of CWD left behind after logging, 40 years to equal the mean CWD mass in 500-year-old forest, and more than 150 years to equal the mean total live and dead wood in an old-growth stand. At a rotation age of 80 years, regenerating stands stored approximately half the wood C of the remaining nearby old-growth forests (predominant age 500 years), indicating that conversion of old-growth forests to younger managed forests results in a significant net release of C to the atmosphere.
Dispersal limitation induces long-term biomass collapse in overhunted Amazonian forests

PubMed Central

Peres, Carlos A.; Emilio, Thaise; Schietti, Juliana; Desmoulière, Sylvain J. M.; Levi, Taal

2016-01-01

Tropical forests are the global cornerstone of biological diversity, and store 55% of the forest carbon stock globally, yet sustained provisioning of these forest ecosystem services may be threatened by hunting-induced extinctions of plant–animal mutualisms that maintain long-term forest dynamics. Large-bodied Atelinae primates and tapirs in particular offer nonredundant seed-dispersal services for many large-seeded Neotropical tree species, which on average have higher wood density than smaller-seeded and wind-dispersed trees. We used field data and models to project the spatial impact of hunting on large primates by ∼1 million rural households throughout the Brazilian Amazon. We then used a unique baseline dataset on 2,345 1-ha tree plots arrayed across the Brazilian Amazon to model changes in aboveground forest biomass under different scenarios of hunting-induced large-bodied frugivore extirpation. We project that defaunation of the most harvest-sensitive species will lead to losses in aboveground biomass of between 2.5–5.8% on average, with some losses as high as 26.5–37.8%. These findings highlight an urgent need to manage the sustainability of game hunting in both protected and unprotected tropical forests, and place full biodiversity integrity, including populations of large frugivorous vertebrates, firmly in the agenda of reducing emissions from deforestation and forest degradation (REDD+) programs. PMID:26811455
Above-ground biomass and structure of 260 African tropical forests

PubMed Central

Lewis, Simon L.; Sonké, Bonaventure; Sunderland, Terry; Begne, Serge K.; Lopez-Gonzalez, Gabriela; van der Heijden, Geertje M. F.; Phillips, Oliver L.; Affum-Baffoe, Kofi; Baker, Timothy R.; Banin, Lindsay; Bastin, Jean-François; Beeckman, Hans; Boeckx, Pascal; Bogaert, Jan; De Cannière, Charles; Chezeaux, Eric; Clark, Connie J.; Collins, Murray; Djagbletey, Gloria; Djuikouo, Marie Noël K.; Droissart, Vincent; Doucet, Jean-Louis; Ewango, Cornielle E. N.; Fauset, Sophie; Feldpausch, Ted R.; Foli, Ernest G.; Gillet, Jean-François; Hamilton, Alan C.; Harris, David J.; Hart, Terese B.; de Haulleville, Thales; Hladik, Annette; Hufkens, Koen; Huygens, Dries; Jeanmart, Philippe; Jeffery, Kathryn J.; Kearsley, Elizabeth; Leal, Miguel E.; Lloyd, Jon; Lovett, Jon C.; Makana, Jean-Remy; Malhi, Yadvinder; Marshall, Andrew R.; Ojo, Lucas; Peh, Kelvin S.-H.; Pickavance, Georgia; Poulsen, John R.; Reitsma, Jan M.; Sheil, Douglas; Simo, Murielle; Steppe, Kathy; Taedoumg, Hermann E.; Talbot, Joey; Taplin, James R. D.; Taylor, David; Thomas, Sean C.; Toirambe, Benjamin; Verbeeck, Hans; Vleminckx, Jason; White, Lee J. T.; Willcock, Simon; Woell, Hannsjorg; Zemagho, Lise

2013-01-01

We report above-ground biomass (AGB), basal area, stem density and wood mass density estimates from 260 sample plots (mean size: 1.2 ha) in intact closed-canopy tropical forests across 12 African countries. Mean AGB is 395.7 Mg dry mass ha−1 (95% CI: 14.3), substantially higher than Amazonian values, with the Congo Basin and contiguous forest region attaining AGB values (429 Mg ha−1) similar to those of Bornean forests, and significantly greater than East or West African forests. AGB therefore appears generally higher in palaeo- compared with neotropical forests. However, mean stem density is low (426 ± 11 stems ha−1 greater than or equal to 100 mm diameter) compared with both Amazonian and Bornean forests (cf. approx. 600) and is the signature structural feature of African tropical forests. While spatial autocorrelation complicates analyses, AGB shows a positive relationship with rainfall in the driest nine months of the year, and an opposite association with the wettest three months of the year; a negative relationship with temperature; positive relationship with clay-rich soils; and negative relationships with C : N ratio (suggesting a positive soil phosphorus–AGB relationship), and soil fertility computed as the sum of base cations. The results indicate that AGB is mediated by both climate and soils, and suggest that the AGB of African closed-canopy tropical forests may be particularly sensitive to future precipitation and temperature changes. PMID:23878327
Below and above-ground carbon distribution along a rainfall gradient. A case of the Zambezi teak forests, Zambia

NASA Astrophysics Data System (ADS)

Ngoma, Justine; Moors, Eddy; Kruijt, Bart; Speer, James H.; Vinya, Royd; Chidumayo, Emmanuel N.; Leemans, Rik

2018-02-01

Understanding carbon (C) stocks or biomass in forests is important to examine how forests mitigate climate change. To estimate biomass in stems, branches and roots takes intensive fieldwork to uproot, cut and weigh the mass of each component. Different models or equations are also required. Our research focussed on the dry tropical Zambezi teak forests and we studied their structure at three sites following a rainfall gradient in Zambia. We sampled 3558 trees at 42 plots covering a combined area of 15ha. Using data from destructive tree samples, we developed mixed-species biomass models to estimate above ground biomass for small (<5 cm diameter at breast height (DBH, 1.3 m above-ground)) and large (≥5 cm DBH) trees involving 90 and 104 trees respectively, that belonged to 12 species. A below-ground biomass model was developed from seven trees of three species (16-44 cm DBH) whose complete root systems were excavated. Three stump models were also derived from these uprooted trees. Finally, we determined the C fractions from 194 trees that belonged to 12 species. The analysis revealed that DBH was the only predictor that significantly correlated to both above-ground and below-ground biomass. We found a mean root-to-shoot ratio of 0.38:0.62. The C fraction in leaves ranged from 39% to 42%, while it varied between 41% and 46% in wood. The C fraction was highest at the Kabompo site that received the highest rainfall, and lowest at the intermediate Namwala site. The C stocks varied between 15 and 36 ton C ha-1 and these stocks where highest at the wetter Kabompo site and lowest at the drier Sesheke site. Our results indicate that the projected future rainfall decrease for southern Africa, will likely reduce the C storage potential of the Zambezi teak forests, thereby adversely affecting their mitigating role in climate change.
VT0005 In Action: National Forest Biomass Inventory Using Airborne Lidar Sampling

NASA Astrophysics Data System (ADS)

Saatchi, S. S.; Xu, L.; Meyer, V.; Ferraz, A.; Yang, Y.; Shapiro, A.; Bastin, J. F.

2016-12-01

Tropical countries are required to produce robust and verifiable estimates of forest carbon stocks for successful implementation of climate change mitigation. Lack of systematic national inventory data due to access, cost, and infrastructure, has impacted the capacity of most tropical countries to accurately report the GHG emissions to the international community. Here, we report on the development of the aboveground forest carbon (AGC) map of Democratic Republic of Congo (DRC) by using the VCS (Verified Carbon Standard) methodology developed by Sassan Saatchi (VT0005) using high-resolution airborne LiDAR samples. The methodology provides the distribution of the carbon stocks in aboveground live trees of more than 150 million ha of forests at 1-ha spatial resolution in DRC using more than 430, 000 ha of systematic random airborne Lidar inventory samples of forest structure. We developed a LIDAR aboveground biomass allometry using more than 100 1-ha plots across forest types and power-law model with LIDAR height metrics and average landscape scale wood density. The methodology provided estimates of forest biomass over the entire country using two approaches: 1) mean, variance, and total carbon estimates for each forest type present in DRC using inventory statistical techniques, and 2) a wall-to-wall map of the forest biomass extrapolated using satellite radar (ALOS PALSAR), surface topography from SRTM, and spectral information from Landsat (TM) and machine learning algorithms. We present the methodology, the estimates of carbon stocks and the spatial uncertainty over the entire country. AcknowledgementsThe theoretical research was carried out partially at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration, and the design and implementation in the Democratic Republic of Congo was carried out at the Institute of Environment and Sustainability at University of California Los Angeles through the support of the International Climate Initiative of the German Ministry of Environment, Conservation and Nuclear Security, and the KFW Development Bank.
Do Variations in Detrital Inputs Influence Stable Soil Organic Matter? - An Experimental Approach

NASA Astrophysics Data System (ADS)

Lajtha, K.; Townsend, K.; Brewer, E.; Caldwell, B.; Kalbitz, K.; Plante, A.

2007-12-01

Recognition of the importance of feedbacks from plants in determining soil nutrient dynamics and C storage led to a large number of litter decomposition studies. Despite growing knowledge of short-term litter dynamics, we know relatively little about the fate of plant litter and its role in determining SOM content and nutrient cycling over time scales ranging from decades and centuries. To address this gap, we established long-term studies of controls on soil organic matter formation in an old-growth forest at the H.J. Andrews Experimental Forest, OR. This study complements a network of recently established similar experiments that pan climatic and soil gradients, as well as the original DIRT experiment established in the Wisconsin Arboretum in 1956 in both grassland and forested sites. The central goal of the DIRT project is to assess how rates and sources of plant litter inputs control the accumulation and dynamics of organic matter and nutrients in forest soils over decadal time scales. Treatment plots include doubled litter (needle) inputs , doubled wood, no above ground litter (screened) inputs, no root inputs (trenched), and no inputs (screened and trenched). For the 50th anniversary of the Wisconsin sites and the 10th anniversary of the H.J. Andrews site, we used sequential density fractionation of soils from all treatments to determine if adding or removing either below- or above-ground litter inputs influenced carbon stabilization as soil organic matter. After 50 years, double litter plots in both prairie and forested soils had higher %C in the 0-10 cm horizon. In the forested site, plots showed increased C content of the lightest fraction, which represents relatively young SOM with a short turnover time. However, the first two heavy fractions also showed increases in C with added aboveground litter, suggesting the importance of aboveground litter inputs to SOM in the forest. No such pattern existed for the prairie soil, and we hypothesize that this is because aboveground, labile litter adds very little to stabilized SOM in grasslands, and that root-derived C is the dominant control on SOM stabilization in grasslands. These results were confirmed with analysis of labile C (short -term respiration measurements) and acid hydrolysis resistant C across treatments. The relative contribution of aboveground vs. belowground litter was analyzed through the analysis of cutin and suberin acids, and we found that the detrital source of litter was retained in soils and could be fingerprinted through this analysis. Thermal analysis, including thermogravimetry (TG) and differential scanning calorimetry (DSC) performed simultaneously is currently being applied to explore both SOM quality and stability.
Nutrient Budgets in Successional Northern Hardwood Forests: Uncertainty in soil, root, and tree concentrations and pools (Invited)

NASA Astrophysics Data System (ADS)

Yanai, R. D.; Bae, K.; Levine, C. R.; Lilly, P.; Vadeboncoeur, M. A.; Fatemi, F. R.; Blum, J. D.; Arthur, M.; Hamburg, S.

2013-12-01

Ecosystem nutrient budgets are difficult to construct and even more difficult to replicate. As a result, uncertainty in the estimates of pools and fluxes are rarely reported, and opportunities to assess confidence through replicated measurements are rare. In this study, we report nutrient concentrations and contents of soil and biomass pools in northern hardwood stands in replicate plots within replicate stands in 3 age classes (14-19 yr, 26-29 yr, and > 100 yr) at the Bartlett Experimental Forest, USA. Soils were described by quantitative soil pits in three plots per stand, excavated by depth increment to the C horizon and analyzed by a sequential extraction procedure. Variation in soil mass among pits within stands averaged 28% (coefficient of variation); variation among stands within an age class ranged from 9-25%. Variation in nutrient concentrations were higher still (averaging 38%, within element, depth increment, and extraction type), perhaps because the depth increments contained varying proportions of genetic horizons. To estimate nutrient contents of aboveground biomass, we propagated model uncertainty through allometric equations, and found errors ranging from 3-7%, depending on the stand. The variation in biomass among plots within stands (6-19%) was always larger than the allometric uncertainties. Variability in measured nutrient concentrations of tree tissues were more variable than the uncertainty in biomass. Foliage had the lowest variability (averaging 16% for Ca, Mg, K, N and P within age class and species), and wood had the highest (averaging 30%), when reported in proportion to the mean, because concentrations in wood are low. For Ca content of aboveground biomass, sampling variation was the greatest source of uncertainty. Coefficients of variation among plots within a stand averaged 16%; stands within an age class ranged from 5-25% CV, including uncertainties in tree allometry and tissue chemistry. Uncertainty analysis can help direct research effort to areas most in need of improvement. In systems such as the one we studied, more intensive sampling would be the best approach to reducing uncertainty, as natural spatial variation was higher than model or measurement uncertainties.
Ecosystem carbon density and allocation across a chronosequence of longleaf pine forests.

PubMed

Samuelson, Lisa J; Stokes, Thomas A; Butnor, John R; Johnsen, Kurt H; Gonzalez-Benecke, Carlos A; Martin, Timothy A; Cropper, Wendell P; Anderson, Pete H; Ramirez, Michael R; Lewis, John C

2017-01-01

Forests can partially offset greenhouse gas emissions and contribute to climate change mitigation, mainly through increases in live biomass. We quantified carbon (C) density in 20 managed longleaf pine (Pinus palustris Mill.) forests ranging in age from 5 to 118 years located across the southeastern United States and estimated above- and belowground C trajectories. Ecosystem C stock (all pools including soil C) and aboveground live tree C increased nonlinearly with stand age and the modeled asymptotic maxima were 168 Mg C/ha and 80 Mg C/ha, respectively. Accumulation of ecosystem C with stand age was driven mainly by increases in aboveground live tree C, which ranged from <1 Mg C/ha to 74 Mg C/ha and comprised <1% to 39% of ecosystem C. Live root C (sum of below-stump C, ground penetrating radar measurement of lateral root C, and live fine root C) increased with stand age and represented 4-22% of ecosystem C. Soil C was related to site index, but not to stand age, and made up 39-92% of ecosystem C. Live understory C, forest floor C, downed dead wood C, and standing dead wood C were small fractions of ecosystem C in these frequently burned stands. Stand age and site index accounted for 76% of the variation in ecosystem C among stands. The mean root-to-shoot ratio calculated as the average across all stands (excluding the grass-stage stand) was 0.54 (standard deviation of 0.19) and higher than reports for other conifers. Long-term accumulation of live tree C, combined with the larger role of belowground accumulation of lateral root C than in other forest types, indicates a role of longleaf pine forests in providing disturbance-resistant C storage that can balance the more rapid C accumulation and C removal associated with more intensively managed forests. Although other managed southern pine systems sequester more C over the short-term, we suggest that longleaf pine forests can play a meaningful role in regional forest C management. © 2016 by the Ecological Society of America.
Influence of tree size, taxonomy, and edaphic conditions on heart rot in mixed-dipterocarp Bornean rainforests: implications for aboveground biomass estimates

NASA Astrophysics Data System (ADS)

Heineman, K. D.; Russo, S. E.; Baillie, I. C.; Mamit, J. D.; Chai, P. P.-K.; Chai, L.; Hindley, E. W.; Lau, B.-T.; Tan, S.; Ashton, P. S.

2015-05-01

Fungal decay of heartwood creates hollows and areas of reduced wood density within the stems of living trees known as heart rot. Although heart rot is acknowledged as a source of error in forest aboveground biomass estimates, there are few datasets available to evaluate the environmental controls over heart rot infection and severity in tropical forests. Using legacy and recent data from drilled, felled, and cored stems in mixed dipterocarp forests in Sarawak, Malaysian Borneo, we quantified the frequency and severity of heart rot, and used generalized linear mixed effect models to characterize the association of heart rot with tree size, wood density, taxonomy, and edaphic conditions. Heart rot was detected in 55% of felled stems > 30 cm DBH, while the detection frequency was lower for stems of the same size evaluated by non-destructive drilling (45%) and coring (23%) methods. Heart rot severity, defined as the percent stem volume lost in infected stems, ranged widely from 0.1-82.8%. Tree taxonomy explained the greatest proportion of variance in heart rot frequency and severity among the fixed and random effects evaluated in our models. Heart rot frequency, but not severity, increased sharply with tree diameter, ranging from 56% infection across all datasets in stems > 50 cm DBH to 11% in trees 10-30 cm DBH. The frequency and severity of heart rot increased significantly in soils with low pH and cation concentrations in topsoil, and heart rot was more common in tree species associated with dystrophic sandy soils than with nutrient-rich clays. When scaled to forest stands, the percent of stem biomass lost to heart rot varied significantly with soil properties, and we estimate that 7% of the forest biomass is in some stage of heart rot decay. This study demonstrates not only that heart rot is a significant source of error in forest carbon estimates, but also that it strongly covaries with soil resources, underscoring the need to account for edaphic variation in estimating carbon storage in tropical forests.
Water limitations on forest carbon cycling and conifer traits along a steep climatic gradient in the Cascade Mountains, Oregon

NASA Astrophysics Data System (ADS)

Berner, L. T.; Law, B. E.

2015-11-01

Severe droughts occurred in the western United States during recent decades, and continued human greenhouse gas emissions are expected to exacerbate warming and drying in this region. We investigated the role of water availability in shaping forest carbon cycling and morphological traits in the eastern Cascade Mountains, Oregon, focusing on the transition from low-elevation, dry western juniper (Juniperus occidentalis) woodlands to higher-elevation, wetter ponderosa pine (Pinus ponderosa) and grand fir (Abies grandis) forests. We examined 12 sites in mature forests that spanned a 1300 mm yr-1 gradient in mean growing-year climate moisture index (CMIgy ), computed annually (1964 to 2013) as monthly precipitation minus reference evapotranspiration and summed October to September. Maximum leaf area, annual aboveground productivity, and aboveground live tree biomass increased with CMIgy (r2 = 0.67-0.88, P < 0.05), approximately 50-, 30-, and 10-fold along this drier to wetter gradient. Interannual fluctuations in CMI affected the annual radial growth of 91 % of juniper, 51 % of pine, and 12 % of fir individuals from 1964 to 2013. The magnitude of the site-average growth-CMI correlations decreased with increased CMIgy (r2 = 0.53, P < 0.05). All three species, particularly fir, experienced pronounced declines in radial growth from c. 1985 to 1994, coinciding with a period of sustained below-average CMIgy and extensive insect outbreak. Traits of stress-tolerant juniper included short stature, high wood density for cavitation resistance, and high investment in water transport relative to leaf area. Species occupying wetter areas invested more resources in height growth in response to competition for light relative to investment in hydraulic architecture. Consequently, maximum tree height, leaf area : sapwood area ratio, and stem wood density were all correlated with CMIgy . The tight coupling of forest carbon cycling and species traits with water availability suggests that warmer and drier conditions projected for the 21st century could have significant biogeochemical, ecological, and social consequences in the Pacific Northwest.
Water limitations on forest carbon cycling and conifer traits along a steep climatic gradient in the Cascade Mountains, Oregon

NASA Astrophysics Data System (ADS)

Berner, L. T.; Law, B. E.

2015-09-01

Severe droughts occurred in the western United States during recent decades and continued human greenhouse gas emissions are expected to exacerbate warming and drying in this region. We investigated the role of water availability in shaping forest carbon cycling and morphological traits in the eastern Cascade Mountains, Oregon, focusing on the transition from low-elevation, dry western juniper (Juniperus occidentalis) woodlands to higher-elevation, wetter ponderosa pine (Pinus ponderosa) and grand fir (Abies grandis) forests. We examined 12 sites in mature forests that spanned a 1300 mm yr-1 gradient in mean growing-year climate moisture index (CMIgy ), computed annually (1964 to 2013) as monthly precipitation minus reference evapotranspiration and summed October to September. Maximum leaf area, annual aboveground productivity, and aboveground live tree biomass increased with CMIgy (r2 = 0.58-0.85, P < 0.05), approximately 50-, 30-, and 10-fold along this drier to wetter gradient. Interannual fluctuations in CMI affected the annual radial growth of 91 % of juniper, 51 % of pine, and 12 % of fir from 1964 to 2013. The magnitude of the site-average growth-CMI correlations decreased with increased CMIgy (r2 = 0.65, P < 0.05). All three species, particularly fir, experienced pronounced declines in radial growth from ca. 1985 to 1994, coinciding with a period of sustained below-average CMIgy and extensive insect outbreak. Traits of stress-tolerant juniper included short stature, high wood density for cavitation resistance, and high investment in water transport relative to leaf area. Species occupying wetter areas invested more resources in height growth in response to competition for light relative to investment in hydraulic architecture. Correspondingly, maximum tree height, leaf area:sapwood area ratio, and stem wood density were all correlated with CMIgy . The tight coupling of forest carbon cycling and species traits with water availability suggests that warmer and drier conditions projected for the 21st century could have significant biogeochemical, ecological, and social consequences in the Pacific Northwest.
Occurrence of termites (Isoptera) on living and standing dead trees in a tropical dry forest in Mexico.

PubMed

Calderón-Cortés, Nancy; Escalera-Vázquez, Luis H; Oyama, Ken

2018-01-01

Termites play a key role as ecosystem engineers in numerous ecological processes though their role in the dynamics of wood degradation in tropical dry forests, particularly at the level of the crown canopy, has been little studied. In this study, we analysed the occurrence of termites in the forest canopy by evaluating the density and proportion of living and standing dead trees associated with termites in deciduous and riparian habitats of the tropical dry forest in Chamela, Mexico. The results indicated that 60-98% of standing dead trees and 23-59% of living trees in Chamela were associated with termites. In particular, we found that the density of standing dead trees was higher in deciduous forests (0.057-0.066 trees/m 2 ) than in riparian forests (0.022 and 0.027 trees/m 2 ), even though the proportion of trees was not significantly different among habitats. Additionally, we found a higher density of trees associated with termites in trees of smaller size classes (0.01-0.09 trees/m 2 ) than in larger class sizes (0-0.02 trees/m 2 ). Interestingly, 72% of variation in the density of trees associated with termites is explained by the density of standing dead trees. Overall, these results indicate that standing dead tree availability might be the main factor regulating termite populations in Chamela forest and suggest that termites could play a key role in the decomposition of above-ground dead wood, mediating the incorporation of suspended and standing dead wood into the soil.
Occurrence of termites (Isoptera) on living and standing dead trees in a tropical dry forest in Mexico

PubMed Central

Escalera-Vázquez, Luis H.; Oyama, Ken

2018-01-01

Termites play a key role as ecosystem engineers in numerous ecological processes though their role in the dynamics of wood degradation in tropical dry forests, particularly at the level of the crown canopy, has been little studied. In this study, we analysed the occurrence of termites in the forest canopy by evaluating the density and proportion of living and standing dead trees associated with termites in deciduous and riparian habitats of the tropical dry forest in Chamela, Mexico. The results indicated that 60–98% of standing dead trees and 23–59% of living trees in Chamela were associated with termites. In particular, we found that the density of standing dead trees was higher in deciduous forests (0.057–0.066 trees/m2) than in riparian forests (0.022 and 0.027 trees/m2), even though the proportion of trees was not significantly different among habitats. Additionally, we found a higher density of trees associated with termites in trees of smaller size classes (0.01–0.09 trees/m2) than in larger class sizes (0–0.02 trees/m2). Interestingly, 72% of variation in the density of trees associated with termites is explained by the density of standing dead trees. Overall, these results indicate that standing dead tree availability might be the main factor regulating termite populations in Chamela forest and suggest that termites could play a key role in the decomposition of above-ground dead wood, mediating the incorporation of suspended and standing dead wood into the soil. PMID:29785342
Intraspecific Variation in Wood Anatomical, Hydraulic, and Foliar Traits in Ten European Beech Provenances Differing in Growth Yield

PubMed Central

Hajek, Peter; Kurjak, Daniel; von Wühlisch, Georg; Delzon, Sylvain; Schuldt, Bernhard

2016-01-01

In angiosperms, many studies have described the inter-specific variability of hydraulic-related traits and little is known at the intra-specific level. This information is however mandatory to assess the adaptive capacities of tree populations in the context of increasing drought frequency and severity. Ten 20-year old European beech (Fagus sylvatica L.) provenances representing the entire distribution range throughout Europe and differing significantly in aboveground biomass increment (ABI) by a factor of up to four were investigated for branch wood anatomical, hydraulic, and foliar traits in a provenance trial located in Northern Europe. We quantified to which extend xylem hydraulic and leaf traits are under genetic control and tested whether the xylem hydraulic properties (hydraulic efficiency and safety) trades off with yield and wood anatomical and leaf traits. Our results showed that only three out of 22 investigated ecophysiological traits showed significant genetic differentiations between provenances, namely vessel density (VD), the xylem pressure causing 88% loss of hydraulic conductance and mean leaf size. Depending of the ecophysiological traits measured, genetic differentiation between populations explained 0–14% of total phenotypic variation, while intra-population variability was higher than inter-population variability. Most wood anatomical traits and some foliar traits were additionally related to the climate of provenance origin. The lumen to sapwood area ratio, vessel diameter, theoretical specific conductivity and theoretical leaf-specific conductivity as well as the C:N-ratio increased with climatic aridity at the place of origin while the carbon isotope signature (δ13C) decreased. Contrary to our assumption, none of the wood anatomical traits were related to embolism resistance but were strong determinants of hydraulic efficiency. Although ABI was associated with both VD and δ13C, both hydraulic efficiency and embolism resistance were unrelated, disproving the assumed trade-off between hydraulic efficiency and safety. European beech seems to compensate increasing water stress with growing size mainly by adjusting vessel number and not vessel diameter. In conclusion, European beech has a high potential capacity to cope with climate change due to the high degree of intra-population genetic variability. PMID:27379112
Intraspecific Variation in Wood Anatomical, Hydraulic, and Foliar Traits in Ten European Beech Provenances Differing in Growth Yield.

PubMed

Hajek, Peter; Kurjak, Daniel; von Wühlisch, Georg; Delzon, Sylvain; Schuldt, Bernhard

2016-01-01

In angiosperms, many studies have described the inter-specific variability of hydraulic-related traits and little is known at the intra-specific level. This information is however mandatory to assess the adaptive capacities of tree populations in the context of increasing drought frequency and severity. Ten 20-year old European beech (Fagus sylvatica L.) provenances representing the entire distribution range throughout Europe and differing significantly in aboveground biomass increment (ABI) by a factor of up to four were investigated for branch wood anatomical, hydraulic, and foliar traits in a provenance trial located in Northern Europe. We quantified to which extend xylem hydraulic and leaf traits are under genetic control and tested whether the xylem hydraulic properties (hydraulic efficiency and safety) trades off with yield and wood anatomical and leaf traits. Our results showed that only three out of 22 investigated ecophysiological traits showed significant genetic differentiations between provenances, namely vessel density (VD), the xylem pressure causing 88% loss of hydraulic conductance and mean leaf size. Depending of the ecophysiological traits measured, genetic differentiation between populations explained 0-14% of total phenotypic variation, while intra-population variability was higher than inter-population variability. Most wood anatomical traits and some foliar traits were additionally related to the climate of provenance origin. The lumen to sapwood area ratio, vessel diameter, theoretical specific conductivity and theoretical leaf-specific conductivity as well as the C:N-ratio increased with climatic aridity at the place of origin while the carbon isotope signature (δ(13)C) decreased. Contrary to our assumption, none of the wood anatomical traits were related to embolism resistance but were strong determinants of hydraulic efficiency. Although ABI was associated with both VD and δ(13)C, both hydraulic efficiency and embolism resistance were unrelated, disproving the assumed trade-off between hydraulic efficiency and safety. European beech seems to compensate increasing water stress with growing size mainly by adjusting vessel number and not vessel diameter. In conclusion, European beech has a high potential capacity to cope with climate change due to the high degree of intra-population genetic variability.
Changes in mass and nutrient content of wood during decomposition in a south Florida mangrove forest

USGS Publications Warehouse

Romero, L.M.; Smith, T. J.; Fourqurean, J.W.

2005-01-01

1 Large pools of dead wood in mangrove forests following disturbances such as hurricanes may influence nutrient fluxes. We hypothesized that decomposition of wood of mangroves from Florida, USA (Avicennia germinans, Laguncularia racemosa and Rhizophora mangle), and the consequent nutrient dynamics, would depend on species, location in the forest relative to freshwater and marine influences and whether the wood was standing, lying on the sediment surface or buried. 2 Wood disks (8-10 cm diameter, 1 cm thick) from each species were set to decompose at sites along the Shark River, either buried in the sediment, on the soil surface or in the air (above both the soil surface and high tide elevation). 3 A simple exponential model described the decay of wood in the air, and neither species nor site had any effect on the decay coefficient during the first 13 months of decomposition. 4 Over 28 months of decomposition, buried and surface disks decomposed following a two-component model, with labile and refractory components. Avicennia germinans had the largest labile component (18 ?? 2% of dry weight), while Laguncularia racemosa had the lowest (10 ?? 2%). Labile components decayed at rates of 0.37-23.71% month -1, while refractory components decayed at rates of 0.001-0.033% month-1. Disks decomposing on the soil surface had higher decay rates than buried disks, but both were higher than disks in the air. All species had similar decay rates of the labile and refractory components, but A. germinans exhibited faster overall decay because of a higher proportion of labile components. 5 Nitrogen content generally increased in buried and surface disks, but there was little change in N content of disks in the air over the 2-year study. Between 17% and 68% of total phosphorus in wood leached out during the first 2 months of decomposition, with buried disks having the greater losses, P remaining constant or increasing slightly thereafter. 6 Newly deposited wood from living trees was a short-term source of N for the ecosystem but, by the end of 2 years, had become a net sink. Wood, however, remained a source of P for the ecosystem. 7 As in other forested ecosystems, coarse woody debris can have a significant impact on carbon and nutrient dynamics in mangrove forests. The prevalence of disturbances, such as hurricanes, that can deposit large amounts of wood on the forest floor accentuates the importance of downed wood in these forests. ?? 2005 British Ecological Society.
Coarse woody debris and soil respiration 6 years post-tornado in a Piedmont forest blowdown

NASA Astrophysics Data System (ADS)

Oldfield, C.; Peterson, C. J.

2017-12-01

Severe wind disturbances can rapidly change carbon pools and fluxes in forests, causing a site to switch from a carbon sink to a source in a matter of minutes. Moreover, salvage logging after a disturbance can result in disturbed and compacted soil, altered woody debris carbon pools, and seedling mortality, all of which may further alter carbon dynamics beyond that caused by the disturbance itself. We measured down dead wood and soil respiration in the summer of 2017 at Boggs Creek Recreation Area in the Piedmont of northeast Georgia, the site of a severe tornado in 2011. Down dead wood and soil respiration were compared in control (intact forest), salvaged, and unsalvaged areas. Megagrams per hectare of down dead wood was significantly higher in the unsalvaged condition than the control or salvage logging condition (ANOVAs, p<0.05 in both cases). Conversely, the volume of down dead wood was not significantly different in the control when compared to the salvage logging condition (p=0.99). Soil respiration was significantly higher in the salvage logged condition than the control (p<0.05), but was not significantly different between the unsalvaged condition and the control (p=0.30) or the unsalvaged condition and the salvaged condition (p=0.58). This research shows that wind disturbances have a lasting impact on the amount of down dead wood in a forest, and salvage logging may lead to greater soil respiration years after the initial disturbance, both of which will influence the time elapsed before a disturbed forest switches from carbon source to carbon sink. Further research is needed to determine the duration of these effects, along with the carbon consequences for other forest carbon pools.
Host preference and species richness of wood-inhabiting aphyllophoraceous fungi in a cool temperate area of Japan.

PubMed

Yamashita, Satoshi; Hattori, Tsutomu; Abe, Hisashi

2010-01-01

We examined the species richness and host utilization patterns of wood-inhabiting aphyllophoraceous fungi (polypores and related fungi) in an old-growth beech and oak forest in a cool, temperate area of Japan. Coarse woody debris (CWD) > or = 20 cm diam within a 6 ha plot was surveyed in Sep 2002. Tree genus, diameter, decay class and tree part of CWD samples were recorded. Fruiting bodies of aphyllophoraceous fungi that arose from the CWD were surveyed three times and identified to species. In total 256 CWD samples from 12 tree genera were surveyed with Quercus being the most frequent followed by Castanea and Fagus. From 196 CWD samples we recorded 436 wood-inhabiting fungi belonging to 63 species. Fifteen fungal species had at least 10 records, with Hymenochaete rubiginosa, Daedalea dickinsii, Xylobolus frustulatus, Rigidoporus cinereus and the small form of Fomes fomentarius being the most frequent. The number of fungal species that appeared on Fagus was significantly larger than that on Castanea, when the number of fruiting bodies collected was at least 50. The occurrences of the 15 dominant fungal species, except Trametes versicolor, were related to traits of the CWD. Tree genus was a predictor variable that affected the appearance of 11 of the 15 species of wood-inhabiting fungi. Only the tree part was selected for the models of Rigidoporus eminens, Schizopora flavipora and Stereum ostrea. Our results suggest that tree genus and tree part are important factors determining fungal community structure because these were selected as complementary predictor variables. Both oak and beech appear to be the most important tree genera for maintaining wood-inhabiting fungal species richness because the fungal flora formed on oak CWD is nearly complementary to those on chestnut, with low fungal species richness.
Markedly divergent estimates of Amazon forest carbon density from ground plots and satellites.

PubMed

Mitchard, Edward T A; Feldpausch, Ted R; Brienen, Roel J W; Lopez-Gonzalez, Gabriela; Monteagudo, Abel; Baker, Timothy R; Lewis, Simon L; Lloyd, Jon; Quesada, Carlos A; Gloor, Manuel; Ter Steege, Hans; Meir, Patrick; Alvarez, Esteban; Araujo-Murakami, Alejandro; Aragão, Luiz E O C; Arroyo, Luzmila; Aymard, Gerardo; Banki, Olaf; Bonal, Damien; Brown, Sandra; Brown, Foster I; Cerón, Carlos E; Chama Moscoso, Victor; Chave, Jerome; Comiskey, James A; Cornejo, Fernando; Corrales Medina, Massiel; Da Costa, Lola; Costa, Flavia R C; Di Fiore, Anthony; Domingues, Tomas F; Erwin, Terry L; Frederickson, Todd; Higuchi, Niro; Honorio Coronado, Euridice N; Killeen, Tim J; Laurance, William F; Levis, Carolina; Magnusson, William E; Marimon, Beatriz S; Marimon Junior, Ben Hur; Mendoza Polo, Irina; Mishra, Piyush; Nascimento, Marcelo T; Neill, David; Núñez Vargas, Mario P; Palacios, Walter A; Parada, Alexander; Pardo Molina, Guido; Peña-Claros, Marielos; Pitman, Nigel; Peres, Carlos A; Poorter, Lourens; Prieto, Adriana; Ramirez-Angulo, Hirma; Restrepo Correa, Zorayda; Roopsind, Anand; Roucoux, Katherine H; Rudas, Agustin; Salomão, Rafael P; Schietti, Juliana; Silveira, Marcos; de Souza, Priscila F; Steininger, Marc K; Stropp, Juliana; Terborgh, John; Thomas, Raquel; Toledo, Marisol; Torres-Lezama, Armando; van Andel, Tinde R; van der Heijden, Geertje M F; Vieira, Ima C G; Vieira, Simone; Vilanova-Torre, Emilio; Vos, Vincent A; Wang, Ophelia; Zartman, Charles E; Malhi, Yadvinder; Phillips, Oliver L

2014-08-01

The accurate mapping of forest carbon stocks is essential for understanding the global carbon cycle, for assessing emissions from deforestation, and for rational land-use planning. Remote sensing (RS) is currently the key tool for this purpose, but RS does not estimate vegetation biomass directly, and thus may miss significant spatial variations in forest structure. We test the stated accuracy of pantropical carbon maps using a large independent field dataset. Tropical forests of the Amazon basin. The permanent archive of the field plot data can be accessed at: http://dx.doi.org/10.5521/FORESTPLOTS.NET/2014_1. Two recent pantropical RS maps of vegetation carbon are compared to a unique ground-plot dataset, involving tree measurements in 413 large inventory plots located in nine countries. The RS maps were compared directly to field plots, and kriging of the field data was used to allow area-based comparisons. The two RS carbon maps fail to capture the main gradient in Amazon forest carbon detected using 413 ground plots, from the densely wooded tall forests of the north-east, to the light-wooded, shorter forests of the south-west. The differences between plots and RS maps far exceed the uncertainties given in these studies, with whole regions over- or under-estimated by > 25%, whereas regional uncertainties for the maps were reported to be < 5%. Pantropical biomass maps are widely used by governments and by projects aiming to reduce deforestation using carbon offsets, but may have significant regional biases. Carbon-mapping techniques must be revised to account for the known ecological variation in tree wood density and allometry to create maps suitable for carbon accounting. The use of single relationships between tree canopy height and above-ground biomass inevitably yields large, spatially correlated errors. This presents a significant challenge to both the forest conservation and remote sensing communities, because neither wood density nor species assemblages can be reliably mapped from space.
Markedly divergent estimates of Amazon forest carbon density from ground plots and satellites

PubMed Central

Mitchard, Edward T A; Feldpausch, Ted R; Brienen, Roel J W; Lopez-Gonzalez, Gabriela; Monteagudo, Abel; Baker, Timothy R; Lewis, Simon L; Lloyd, Jon; Quesada, Carlos A; Gloor, Manuel; ter Steege, Hans; Meir, Patrick; Alvarez, Esteban; Araujo-Murakami, Alejandro; Aragão, Luiz E O C; Arroyo, Luzmila; Aymard, Gerardo; Banki, Olaf; Bonal, Damien; Brown, Sandra; Brown, Foster I; Cerón, Carlos E; Chama Moscoso, Victor; Chave, Jerome; Comiskey, James A; Cornejo, Fernando; Corrales Medina, Massiel; Da Costa, Lola; Costa, Flavia R C; Di Fiore, Anthony; Domingues, Tomas F; Erwin, Terry L; Frederickson, Todd; Higuchi, Niro; Honorio Coronado, Euridice N; Killeen, Tim J; Laurance, William F; Levis, Carolina; Magnusson, William E; Marimon, Beatriz S; Marimon Junior, Ben Hur; Mendoza Polo, Irina; Mishra, Piyush; Nascimento, Marcelo T; Neill, David; Núñez Vargas, Mario P; Palacios, Walter A; Parada, Alexander; Pardo Molina, Guido; Peña-Claros, Marielos; Pitman, Nigel; Peres, Carlos A; Poorter, Lourens; Prieto, Adriana; Ramirez-Angulo, Hirma; Restrepo Correa, Zorayda; Roopsind, Anand; Roucoux, Katherine H; Rudas, Agustin; Salomão, Rafael P; Schietti, Juliana; Silveira, Marcos; de Souza, Priscila F; Steininger, Marc K; Stropp, Juliana; Terborgh, John; Thomas, Raquel; Toledo, Marisol; Torres-Lezama, Armando; van Andel, Tinde R; van der Heijden, Geertje M F; Vieira, Ima C G; Vieira, Simone; Vilanova-Torre, Emilio; Vos, Vincent A; Wang, Ophelia; Zartman, Charles E; Malhi, Yadvinder; Phillips, Oliver L

2014-01-01

Aim The accurate mapping of forest carbon stocks is essential for understanding the global carbon cycle, for assessing emissions from deforestation, and for rational land-use planning. Remote sensing (RS) is currently the key tool for this purpose, but RS does not estimate vegetation biomass directly, and thus may miss significant spatial variations in forest structure. We test the stated accuracy of pantropical carbon maps using a large independent field dataset. Location Tropical forests of the Amazon basin. The permanent archive of the field plot data can be accessed at: http://dx.doi.org/10.5521/FORESTPLOTS.NET/2014_1 Methods Two recent pantropical RS maps of vegetation carbon are compared to a unique ground-plot dataset, involving tree measurements in 413 large inventory plots located in nine countries. The RS maps were compared directly to field plots, and kriging of the field data was used to allow area-based comparisons. Results The two RS carbon maps fail to capture the main gradient in Amazon forest carbon detected using 413 ground plots, from the densely wooded tall forests of the north-east, to the light-wooded, shorter forests of the south-west. The differences between plots and RS maps far exceed the uncertainties given in these studies, with whole regions over- or under-estimated by > 25%, whereas regional uncertainties for the maps were reported to be < 5%. Main conclusions Pantropical biomass maps are widely used by governments and by projects aiming to reduce deforestation using carbon offsets, but may have significant regional biases. Carbon-mapping techniques must be revised to account for the known ecological variation in tree wood density and allometry to create maps suitable for carbon accounting. The use of single relationships between tree canopy height and above-ground biomass inevitably yields large, spatially correlated errors. This presents a significant challenge to both the forest conservation and remote sensing communities, because neither wood density nor species assemblages can be reliably mapped from space. PMID:26430387

Characterization of Scots pine stump-root biomass as feed-stock for gasification.

PubMed

Eriksson, Daniel; Weiland, Fredrik; Hedman, Henry; Stenberg, Martin; Öhrman, Olov; Lestander, Torbjörn A; Bergsten, Urban; Öhman, Marcus

2012-01-01

The main objective was to explore the potential for gasifying Scots pine stump-root biomass (SRB). Washed thin roots, coarse roots, stump heartwood and stump sapwood were characterized (solid wood, milling and powder characteristics) before and during industrial processing. Non-slagging gasification of the SRB fuels and a reference stem wood was successful, and the gasification parameters (synthesis gas and bottom ash characteristics) were similar. However, the heartwood fuel had high levels of extractives (≈19%) compared to the other fuels (2-8%) and thereby ≈16% higher energy contents but caused disturbances during milling, storage, feeding and gasification. SRB fuels could be sorted automatically according to their extractives and moisture contents using near-infrared spectroscopy, and their amounts and quality in forests can be predicted using routinely collected stand data, biomass functions and drill core analyses. Thus, SRB gasification has great potential and the proposed characterizations exploit it. Copyright © 2011 Elsevier Ltd. All rights reserved.
Modeling spatial variation in avian survival and residency probabilities

USGS Publications Warehouse

Saracco, James F.; Royle, J. Andrew; DeSante, David F.; Gardner, Beth

2010-01-01

The importance of understanding spatial variation in processes driving animal population dynamics is widely recognized. Yet little attention has been paid to spatial modeling of vital rates. Here we describe a hierarchical spatial autoregressive model to provide spatially explicit year-specific estimates of apparent survival (phi) and residency (pi) probabilities from capture-recapture data. We apply the model to data collected on a declining bird species, Wood Thrush (Hylocichla mustelina), as part of a broad-scale bird-banding network, the Monitoring Avian Productivity and Survivorship (MAPS) program. The Wood Thrush analysis showed variability in both phi and pi among years and across space. Spatial heterogeneity in residency probability was particularly striking, suggesting the importance of understanding the role of transients in local populations. We found broad-scale spatial patterning in Wood Thrush phi and pi that lend insight into population trends and can direct conservation and research. The spatial model developed here represents a significant advance over approaches to investigating spatial pattern in vital rates that aggregate data at coarse spatial scales and do not explicitly incorporate spatial information in the model. Further development and application of hierarchical capture-recapture models offers the opportunity to more fully investigate spatiotemporal variation in the processes that drive population changes.
Oxidative Potential of ambient particulate matter in Athens, Greece.

NASA Astrophysics Data System (ADS)

Paraskevopoulou, Despina; Bougiatioti, Aikaterini; Fang, Ting; Liakakou, Eleni; Weber, Rodney; Nenes, Athanasios; Mihalopoulos, Nikolaos

2017-04-01

Exposure of populations to airborne particulate matter (PM) is a leading cause of premature death worldwide. Oxidative stress resulting from exposure of chemical species present in PM is a mechanism thought to cause adverse health effects. Apart from radicals present in aerosol, species that can catalytically deplete the antioxidant buffering capacity of cells, called Oxidative Potential (OP), are thought to be particularly toxic. The variability of OP over location, particle age, source and environmental conditions is virtually unknown for most populated regions of the world. Motivated by this, we have built and deployed one of the first operational measurements of OP in Europe at the National Observatory of Athens site in downtown Athens, Greece. OP for fine and coarse mode is measured using a semi-automated dithiothreitol (DTT) assay developed at the Georgia Institute of Technology; the assay measures the oxidation rate of DTT by water-soluble aerosol constituents, and simulates the rate at which the same compounds would deplete antioxidants in-vivo. The DTT oxidation rate per unit volume of air (water-soluble "DTT activity") and aerosol size class (fine, coarse) are used as a measure of aerosol toxicity. We present continuous (24hr average) OP measurements in downtown Athens from July 2016 to January 2017, conducted through quartz fiber filter analysis. The dataset covers a broad range of aerosol sources (pollution from Europe, regional and local biomass burning, dust, marine aerosol, biogenic aerosol) and meteorological conditions. The daily water-soluble DTT activity ranges between 0.02-0.81 nmolmin-1 m-3 (averaging at 0.24 nmolmin-1 m-3) for fine aerosol and between 0.01-0.52 nmolmin-1 m-3 (averaging at 0.08 nmolmin-1 m-3) for coarse particulate matter, indicating that water-soluble fine mode aerosol components possess a significant fraction of the OP. The seasonal variability demonstrates a higher DTT activity during the coldest period of the year for both aerosol fractions; correlation analysis with aerosol tracers provides insights on the relative importance of each aerosol source. We find that OP study shows a reasonable correlation of DTT activity with brown carbon (BrC) (R2=0.47) that ameliorates when BrC derived from wood burning (BrCwb) is taken into consideration (R2=0.56). Wood burning is widely used for domestic heating during wintertime in Greece in place of fuel oil and natural gas since the 2012 economic crisis, so the high OP levels associated with this particular source may exacerbate the health impacts of PM inhalation during periods of intense wood burning. Further attribution of OP with aerosol tracers is then used to quantify the drivers of OP on a seasonal basis.
Elevated temperature and CO(2) concentration effects on xylem anatomy of Scots pine.

PubMed

Kilpeläinen, Antti; Gerendiain, Ane Zubizarreta; Luostarinen, Katri; Peltola, Heli; Kellomäki, Seppo

2007-09-01

We studied the effects of elevated temperature and carbon dioxide concentration ([CO(2)]) alone and together on wood anatomy of 20-year-old Scots pine (Pinus sylvestris L.) trees. The study was conducted in 16 closed chambers, providing a factorial combination of two temperature regimes and two CO(2) concentrations (ambient and elevated), with four trees in each treatment. The climate scenario included a doubling of [CO(2)] and a corresponding increase of 2-6 degrees C in temperature at the site depending on the season. Anatomical characteristics analyzed were annual earlywood, latewood and ring widths, intra-ring wood densities (earlywood, latewood and mean wood density), tracheid width, length, wall thickness, lumen diameter, wall thickness:lumen diameter ratio and mass per unit length (coarseness), and numbers of rays, resin canals and tracheids per xylem cross-sectional area. Elevated [CO(2)] increased ring width in four of six treatment years; earlywood width increased in the first two years and latewood width in the third year. Tracheid walls in both the earlywood and latewood tended to become thicker over the 6-year treatment period when temperature or [CO(2)] was elevated alone, whereas in the combined treatment they tended to become thinner relative to the tracheids of trees grown under ambient conditions. Latewood tracheid lumen diameters were larger in all the treatments relative to ambient conditions over the 6-year period, whereas lumen diameters in earlywood increased only in response to elevated [CO(2)] and were 3-6% smaller in the treatments with elevated temperature than in ambient conditions. Tracheid width, length and coarseness were greater in trees grown in elevated than in ambient temperature. The number of resin canals per mm(2) decreased in the elevated [CO(2)] treatment and increased in the elevated temperature treatments relative to ambient conditions. The treatments decreased the number of rays and tracheids per mm(2) of cross-sectional area, the greatest decrease occurring in the elevated [CO(2)] treatment. It seemed that xylem anatomy was affected more by elevated temperature than by elevated [CO(2)] and that the effects of temperature were confined to the earlywood.
Ecological carbon sequestration via wood harvest and storage (WHS): Can it be a viable climate and energy strategy?

NASA Astrophysics Data System (ADS)

Zeng, N.; Zaitchik, B. F.; King, A. W.; Wullschleger, S. D.

2016-12-01

A carbon sequestration strategy is proposed in which forests are sustainably managed to optimal carbon productivity, and a fraction of the wood is selectively harvested and stored to prevent decomposition under anaerobic, dry or cold conditions. Because a large flux of CO2 is constantly assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. The live trees serve as a `carbon scrubber' or `carbon remover' that provides continuous sequestration (negative emissions). The stored wood is a semi-permanent carbon sink, but also serves as a `biomass/bioenergy reserve' that could be utilized in the future.Based on forest coarse wood production rate, land availability, bioconservation and other practical constraints, we estimate a carbon sequestration potential for wood harvest and storage (WHS) 1-3 GtC y-1. The implementation of such a scheme at our estimated lower value of 1 GtC y-1 would imply a doubling of the current world wood harvest rate. This can be achieved by harvesting wood at a modest harvesting intensity of 1.2 tC ha-1 y-1, over a forest area of 8 Mkm2 (800 Mha). To achieve the higher value of 3 GtC y-1, forests need to be managed this way on half of the world's forested land, or on a smaller area but with higher harvest intensity. However, the actual implementation may face challenges that vary regionally. We propose `carbon sequestration and biomass farms' in the tropical deforestation frontiers with mixed land use for carbon, energy, agriculture, as well as conservation. In another example, the forests damaged by insect infestation could be thinned to reduce fire and harvested for carbon sequestration.We estimate a cost of $10-50/tCO2 for harvest and storage around the landing site. The technique is low tech, distributed and reversible. We compare the potential of WHS with a number of other carbon sequestration methods. We will also show its impact on future land carbon sink and climate target using carbon-cliamte model projections.
Timber volume and aboveground live tree biomass estimations for landscape analyses in the Pacific Northwest

Treesearch

Xiaoping Zhou; Miles A. Hemstrom

2010-01-01

Timber availability, aboveground tree biomass, and changes in aboveground carbon pools are important consequences of landscape management. There are several models available for calculating tree volume and aboveground tree biomass pools. This paper documents species-specific regional equations for tree volume and aboveground live tree biomass estimation that might be...
Atmospheric and geogenic CO2 within the crown and root of spruce (Picea abies L. Karst.) growing in a mofette area

NASA Astrophysics Data System (ADS)

Vodnik, D.; Thomalla, A.; Ferlan, M.; Levanič, T.; Eler, K.; Ogrinc, N.; Wittmann, C.; Pfanz, H.

2018-06-01

Mofettes are often investigated in ecology, either as extreme sites, natural analogues to future conditions under climate change, or model ecosystems for environmental impact assessments of carbon capture and storage systems. Much of this research, however, inadequately addresses the complexity of the gas environment at these sites, mainly focusing on aboveground CO2-enrichment. In the current research, the gaseous environment of Norway spruce (Picea abies (L) Karst.) trees growing at the Stavešinske slepice mofette (NE Slovenia) were studied by measuring both soil ([CO2]soil) and atmospheric CO2 concentrations ([CO2]air). Within the studied site (800 m2), soil CO2 enrichment was spatially heterogeneous; about 25% of the area was characterized by very high [CO2]soil (>40%) and hypoxic conditions. Aboveground gas measurements along vertical profiles not only revealed substantially elevated [CO2]air close to the ground (height up to 1.5 m), but also in the upper heights (20-25 m; crown layer). On the basis δ13C of CO2, it was shown that elevated CO2 relates to a geogenic source. Trees grown in high [CO2]soil were characterized by decreased radial growth; the δ13C of their wood was less negative than in trees growing in normal soil. Unfavorable gaseous soil conditions should generally be accepted as being by far the most important factor affecting (i.e. disturbing) the growth of mofette trees.
Unearthing the hidden world of roots: Root biomass and architecture differ among species within the same guild

PubMed Central

2017-01-01

The potential benefits of planting trees have generated significant interest with respect to sequestering carbon and restoring other forest based ecosystem services. Reliable estimates of carbon stocks are pivotal for understanding the global carbon balance and for promoting initiatives to mitigate CO2 emissions through forest management. There are numerous studies employing allometric regression models that convert inventory into aboveground biomass (AGB) and carbon (C). Yet the majority of allometric regression models do not consider the root system nor do these equations provide detail on the architecture and shape of different species. The root system is a vital piece toward understanding the hidden form and function roots play in carbon accumulation, nutrient and plant water uptake, and groundwater infiltration. Work that estimates C in forests as well as models that are used to better understand the hydrologic function of trees need better characterization of tree roots. We harvested 40 trees of six different species, including their roots down to 2 mm in diameter and created species-specific and multi-species models to calculate aboveground (AGB), coarse root belowground biomass (BGB), and total biomass (TB). We also explore the relationship between crown structure and root structure. We found that BGB contributes ~27.6% of a tree’s TB, lateral roots extend over 1.25 times the distance of crown extent, root allocation patterns varied among species, and that AGB is a strong predictor of TB. These findings highlight the potential importance of including the root system in C estimates and lend important insights into the function roots play in water cycling. PMID:29023553
Impacts of afforestation and silviculture on the soil C balance of tropical tree plantations: belowground C allocation, soil CO2 efflux and C accretion (Invited)

NASA Astrophysics Data System (ADS)

Epron, D.; Koutika, L.; Mareschal, L.; Nouvellon, Y.

2013-12-01

Tropical forest plantations will provide a large part of the global wood supply which is anticipated to increase sharply in the next decades, becoming a valuable source of income in many countries, where they also contribute to land use changes that impact the global carbon (C) cycle. Tropical forest plantations established on previous grasslands are potential C sinks offsetting anthropogenic CO2 emissions. When they are managed on short rotations, the aboveground biomass is frequently removed and transformed into wood products with short lifetimes. The soil is thus the only compartment for durable C sequestration. The soil C budget results from the inputs of C from litterfall, root turnover and residues left at logging stage, balanced by C losses through heterotrophic respiration and leaching of organic C with water flow. Intensive researches have been conducted these last ten years in eucalypt plantations in the Congo on the effects of management options on soil fertility improvement and C sequestration. Our aim is to review important results regarding belowground C allocation, soil CO2 efflux and C accretion in relation to management options. We will specifically address (i) the soil C dynamics after afforestation of a tropical savannah, (ii) the impact of post-harvest residue management, and (iii) the beneficial effect of introducing nitrogen fixing species for C sequestration. Our results on afforestation of previous savannah showed that mechanical soil disturbance for site preparation had no effect on soil CO2 efflux and soil C balance. Soil C increased after afforestation despite a rapid disappearance of the labile savannah-derived C because a large fraction of savannah-derived C is stable and the aboveground litter layer is as the major source of CO2 contributing to soil CO2 efflux. We further demonstrated that the C stock in and on the soil slightly increased after each rotation when large amounts of residues are left at logging stage and that most of eucalypt-derived C is recovered in the fine particulate organic matter fraction (0.25-0.05 mm) and the organo-mineral fraction (< 0.05 mm). While the early tree growth is related to the heterotrophic component of soil CO2 efflux, thus largely dependent on the nutrients released by the decomposition of organic residues left at harvest, the stabilization of the old soil organic C derived from the savannah may depends on the amount of organic residues left at harvest. A greater C accumulation was observed in the soil when eucalypts were grown in mixture with a nitrogen fixing tree despite similar aboveground litter fall and lower fine root biomass. A slowdown of C turnover related to N enrichment might thus be postulated in nitrogen-poor tropical soils, and mixed-species plantation with nitrogen fixing trees might be an important strategy of reforestation or afforestation to offset C emissions.
Species-specific defence responses facilitate conspecifics and inhibit heterospecifics in above–belowground herbivore interactions

PubMed Central

Huang, Wei; Siemann, Evan; Xiao, Li; Yang, Xuefang; Ding, Jianqing

2014-01-01

Conspecific and heterospecific aboveground and belowground herbivores often occur together in nature and their interactions may determine community structure. Here we show how aboveground adults and belowground larvae of the tallow tree specialist beetle Bikasha collaris and multiple heterospecific aboveground species interact to determine herbivore performance. Conspecific aboveground adults facilitate belowground larvae, but other aboveground damage inhibits larvae or has no effect. Belowground larvae increase conspecific adult feeding, but decrease heterospecific aboveground insect feeding and abundance. Chemical analyses and experiments with plant populations varying in phenolics show that all these positive and negative effects on insects are closely related to root and shoot tannin concentrations. Our results show that specific plant herbivore responses allow herbivore facilitation and inhibition to co-occur, likely shaping diverse aboveground and belowground communities. Considering species-specific responses of plants is critical for teasing apart inter- and intraspecific interactions in aboveground and belowground compartments. PMID:25241651
Wood production response to climate change will depend critically on forest composition and structure.

PubMed

Coomes, David A; Flores, Olivier; Holdaway, Robert; Jucker, Tommaso; Lines, Emily R; Vanderwel, Mark C

2014-12-01

Established forests currently function as a major carbon sink, sequestering as woody biomass about 26% of global fossil fuel emissions. Whether forests continue to act as a global sink will depend on many factors, including the response of aboveground wood production (AWP; MgC ha(-1 ) yr(-1) ) to climate change. Here, we explore how AWP in New Zealand's natural forests is likely to change. We start by statistically modelling the present-day growth of 97 199 individual trees within 1070 permanently marked inventory plots as a function of tree size, competitive neighbourhood and climate. We then use these growth models to identify the factors that most influence present-day AWP and to predict responses to medium-term climate change under different assumptions. We find that if the composition and structure of New Zealand's forests were to remain unchanged over the next 30 years, then AWP would increase by 6-23%, primarily as a result of physiological responses to warmer temperatures (with no appreciable effect of changing rainfall). However, if warmth-requiring trees were able to migrate into currently cooler areas and if denser canopies were able to form, then a different AWP response is likely: forests growing in the cool mountain environments would show a 30% increase in AWP, while those in the lowland would hardly respond (on average, -3% when mean annual temperature exceeds 8.0 °C). We conclude that response of wood production to anthropogenic climate change is not only dependent on the physiological responses of individual trees, but is highly contingent on whether forests adjust in composition and structure. © 2014 John Wiley & Sons Ltd.
A universal airborne LiDAR approach for tropical forest carbon mapping.

PubMed

Asner, Gregory P; Mascaro, Joseph; Muller-Landau, Helene C; Vieilledent, Ghislain; Vaudry, Romuald; Rasamoelina, Maminiaina; Hall, Jefferson S; van Breugel, Michiel

2012-04-01

Airborne light detection and ranging (LiDAR) is fast turning the corner from demonstration technology to a key tool for assessing carbon stocks in tropical forests. With its ability to penetrate tropical forest canopies and detect three-dimensional forest structure, LiDAR may prove to be a major component of international strategies to measure and account for carbon emissions from and uptake by tropical forests. To date, however, basic ecological information such as height-diameter allometry and stand-level wood density have not been mechanistically incorporated into methods for mapping forest carbon at regional and global scales. A better incorporation of these structural patterns in forests may reduce the considerable time needed to calibrate airborne data with ground-based forest inventory plots, which presently necessitate exhaustive measurements of tree diameters and heights, as well as tree identifications for wood density estimation. Here, we develop a new approach that can facilitate rapid LiDAR calibration with minimal field data. Throughout four tropical regions (Panama, Peru, Madagascar, and Hawaii), we were able to predict aboveground carbon density estimated in field inventory plots using a single universal LiDAR model (r ( 2 ) = 0.80, RMSE = 27.6 Mg C ha(-1)). This model is comparable in predictive power to locally calibrated models, but relies on limited inputs of basal area and wood density information for a given region, rather than on traditional plot inventories. With this approach, we propose to radically decrease the time required to calibrate airborne LiDAR data and thus increase the output of high-resolution carbon maps, supporting tropical forest conservation and climate mitigation policy.
Effects of tree species and wood particle size on the properties of cement-bonded particleboard manufacturing from tree prunings.

PubMed

Nasser, Ramadan A; Al-Mefarrej, H A; Abdel-Aal, M A; Alshahrani, T S

2014-09-01

This study investigated the possibility of using the prunings of six locally grown tree species in Saudi Arabia for cement-bonded particleboard (CBP) production. Panels were made using four different wood particle sizes and a constant wood/cement ratio (1/3 by weight) and target density (1200 kg/m3). The mechanical properties and dimensional stability of the produced panels were determined. The interfacial area and distribution of the wood particles in cement matrix were also investigated by scanning electron microscopy. The results revealed that the panels produced from these pruning materials at a target density of 1200 kg m(-3) meet the strength and dimensional stability requirements of the commercial CBP panels. The mean moduli of rupture and elasticity (MOR and MOE) ranged from 9.68 to 11.78 N mm2 and from 3952 to 5667 N mm2, respectively. The mean percent water absorption for twenty four hours (WA24) ranged from 12.93% to 23.39%. Thickness swelling values ranged from 0.62% to 1.53%. For CBP panels with high mechanical properties and good dimensional stability, mixed-size or coarse particles should be used. Using the tree prunings for CBPs production may help to solve the problem of getting rid of these residues by reducing their negative effects on environment, which are caused by poor disposal of such materials through direct combustion process and appearance of black cloud and then the impact on human health or the random accumulation and its indirect effects on the environment.
Comparing growth phenology of co-occurring deciduous and evergreen conifers exposed to drought.

PubMed

Swidrak, Irene; Schuster, Roman; Oberhuber, Walter

2013-12-01

Plant phenological events are influenced by climate factors such as temperature and rainfall. To evaluate phenological responses to water availability in a Spring Heath-Pine wood (Erico-Pinetum typicum), the focus of this study was to determine intra-annual dynamics of apical and lateral growth of co-occurring early successional Larix decidua and Pinus sylvestris and late successional Picea abies exposed to drought. The effect of reduced plant water availability on growth phenology was investigated by conducting a rainfall exclusion experiment. Timing of key phenological dates (onset, maximum rate, end, duration) of growth processes were compared among species at the rain-sheltered and control plot during 2011 and 2012. Shoot and needle elongation were monitored on lateral branches in the canopy at c . 16 m height and radial growth was recorded by automatic dendrometers at c . 1.3 m height of > 120 yr old trees. Different sequences in aboveground growth phenology were detected among the three species under the same growing conditions. While onset of radial growth in April through early May was considerably preceded by onset of needle growth in Larix decidua (5 - 6 weeks) and shoot growth in Pinus sylvestris ( c . 3 weeks), it occurred quite simultaneously with onset of shoot growth in Picea abies . Low water availability had a minor impact on onset of aboveground growth, which is related to utilization of stored water, but caused premature cessation of aboveground growth. At the control plot mean growing season length was 130 days in Pinus sylvestris , 95 days in Larix decidua and 73 days in Picea abies supporting the hypothesis that early successional species are resource expenders, while late successional species are more efficient in utilizing resources and develop safer life strategies. High synchronicity found in culmination of radial growth in late spring (mid-May through early June) prior to occurrence of more favourable environmental conditions in summer might indicate sink competition for carbohydrates to belowground organs. This is supported by completion of apical growth in mid June in all species, except for needle growth of Pinus sylvestris , which lasted until early August. Phenological observations of conifers exposed to drought revealed that tree water status early during the growing season determines total annual aboveground growth and besides temperature, species-specific endogenous and/or environmental factors (most likely photoperiod and/or different threshold temperatures) are involved in controlling apical and lateral growth resumption after winter dormancy.
Comparing growth phenology of co-occurring deciduous and evergreen conifers exposed to drought

PubMed Central

Swidrak, Irene; Schuster, Roman; Oberhuber, Walter

2013-01-01

Plant phenological events are influenced by climate factors such as temperature and rainfall. To evaluate phenological responses to water availability in a Spring Heath-Pine wood (Erico-Pinetum typicum), the focus of this study was to determine intra-annual dynamics of apical and lateral growth of co-occurring early successional Larix decidua and Pinus sylvestris and late successional Picea abies exposed to drought. The effect of reduced plant water availability on growth phenology was investigated by conducting a rainfall exclusion experiment. Timing of key phenological dates (onset, maximum rate, end, duration) of growth processes were compared among species at the rain-sheltered and control plot during 2011 and 2012. Shoot and needle elongation were monitored on lateral branches in the canopy at c. 16 m height and radial growth was recorded by automatic dendrometers at c. 1.3 m height of > 120 yr old trees. Different sequences in aboveground growth phenology were detected among the three species under the same growing conditions. While onset of radial growth in April through early May was considerably preceded by onset of needle growth in Larix decidua (5 - 6 weeks) and shoot growth in Pinus sylvestris (c. 3 weeks), it occurred quite simultaneously with onset of shoot growth in Picea abies. Low water availability had a minor impact on onset of aboveground growth, which is related to utilization of stored water, but caused premature cessation of aboveground growth. At the control plot mean growing season length was 130 days in Pinus sylvestris, 95 days in Larix decidua and 73 days in Picea abies supporting the hypothesis that early successional species are resource expenders, while late successional species are more efficient in utilizing resources and develop safer life strategies. High synchronicity found in culmination of radial growth in late spring (mid-May through early June) prior to occurrence of more favourable environmental conditions in summer might indicate sink competition for carbohydrates to belowground organs. This is supported by completion of apical growth in mid June in all species, except for needle growth of Pinus sylvestris, which lasted until early August. Phenological observations of conifers exposed to drought revealed that tree water status early during the growing season determines total annual aboveground growth and besides temperature, species-specific endogenous and/or environmental factors (most likely photoperiod and/or different threshold temperatures) are involved in controlling apical and lateral growth resumption after winter dormancy. PMID:24273375
The relationship between species richness and aboveground biomass in a primary Pinus kesiya forest of Yunnan, southwestern China.

PubMed

Li, Shuaifeng; Lang, Xuedong; Liu, Wande; Ou, Guanglong; Xu, Hui; Su, Jianrong

2018-01-01

The relationship between biodiversity and biomass is an essential element of the natural ecosystem functioning. Our research aims at assessing the effects of species richness on the aboveground biomass and the ecological driver of this relationship in a primary Pinus kesiya forest. We sampled 112 plots of the primary P. kesiya forests in Yunnan Province. The general linear model and the structural equation model were used to estimate relative effects of multivariate factors among aboveground biomass, species richness and the other explanatory variables, including climate moisture index, soil nutrient regime and stand age. We found a positive linear regression relationship between the species richness and aboveground biomass using ordinary least squares regressions. The species richness and soil nutrient regime had no direct significant effect on aboveground biomass. However, the climate moisture index and stand age had direct effects on aboveground biomass. The climate moisture index could be a better link to mediate the relationship between species richness and aboveground biomass. The species richness affected aboveground biomass which was mediated by the climate moisture index. Stand age had direct and indirect effects on aboveground biomass through the climate moisture index. Our results revealed that climate moisture index had a positive feedback in the relationship between species richness and aboveground biomass, which played an important role in a link between biodiversity maintenance and ecosystem functioning. Meanwhile, climate moisture index not only affected positively on aboveground biomass, but also indirectly through species richness. The information would be helpful in understanding the biodiversity-aboveground biomass relationship of a primary P. kesiya forest and for forest management.
The relationship between species richness and aboveground biomass in a primary Pinus kesiya forest of Yunnan, southwestern China

PubMed Central

Li, Shuaifeng; Lang, Xuedong; Liu, Wande; Ou, Guanglong; Xu, Hui

2018-01-01

The relationship between biodiversity and biomass is an essential element of the natural ecosystem functioning. Our research aims at assessing the effects of species richness on the aboveground biomass and the ecological driver of this relationship in a primary Pinus kesiya forest. We sampled 112 plots of the primary P. kesiya forests in Yunnan Province. The general linear model and the structural equation model were used to estimate relative effects of multivariate factors among aboveground biomass, species richness and the other explanatory variables, including climate moisture index, soil nutrient regime and stand age. We found a positive linear regression relationship between the species richness and aboveground biomass using ordinary least squares regressions. The species richness and soil nutrient regime had no direct significant effect on aboveground biomass. However, the climate moisture index and stand age had direct effects on aboveground biomass. The climate moisture index could be a better link to mediate the relationship between species richness and aboveground biomass. The species richness affected aboveground biomass which was mediated by the climate moisture index. Stand age had direct and indirect effects on aboveground biomass through the climate moisture index. Our results revealed that climate moisture index had a positive feedback in the relationship between species richness and aboveground biomass, which played an important role in a link between biodiversity maintenance and ecosystem functioning. Meanwhile, climate moisture index not only affected positively on aboveground biomass, but also indirectly through species richness. The information would be helpful in understanding the biodiversity-aboveground biomass relationship of a primary P. kesiya forest and for forest management. PMID:29324901
Stand structural diversity rather than species diversity enhances aboveground carbon storage in secondary subtropical forests in Eastern China

NASA Astrophysics Data System (ADS)

Ali, Arshad; Yan, En-Rong; Chen, Han Y. H.; Chang, Scott X.; Zhao, Yan-Tao; Yang, Xiao-Dong; Xu, Ming-Shan

2016-08-01

Stand structural diversity, typically characterized by variances in tree diameter at breast height (DBH) and total height, plays a critical role in influencing aboveground carbon (C) storage. However, few studies have considered the multivariate relationships of aboveground C storage with stand age, stand structural diversity, and species diversity in natural forests. In this study, aboveground C storage, stand age, tree species, DBH and height diversity indices, were determined across 80 subtropical forest plots in Eastern China. We employed structural equation modelling (SEM) to test for the direct and indirect effects of stand structural diversity, species diversity, and stand age on aboveground C storage. The three final SEMs with different directions for the path between species diversity and stand structural diversity had a similar goodness of fit to the data. They accounted for 82 % of the variation in aboveground C storage, 55-59 % of the variation in stand structural diversity, and 0.1 to 9 % of the variation in species diversity. Stand age demonstrated strong positive total effects, including a positive direct effect (β = 0.41), and a positive indirect effect via stand structural diversity (β = 0.41) on aboveground C storage. Stand structural diversity had a positive direct effect on aboveground C storage (β = 0.56), whereas there was little total effect of species diversity as it had a negative direct association with, but had a positive indirect effect, via stand structural diversity, on aboveground C storage. The negligible total effect of species diversity on aboveground C storage in the forests under study may have been attributable to competitive exclusion with high aboveground biomass, or a historical logging preference for productive species. Our analyses suggested that stand structural diversity was a major determinant for variations in aboveground C storage in the secondary subtropical forests in Eastern China. Hence, maintaining tree DBH and height diversity through silvicultural operations might constitute an effective approach for enhancing aboveground C storage in these forests.
Seasonal carbon storage and growth in Mediterranean tree seedlings under different water conditions.

PubMed

Sanz-Pérez, Virginia; Castro-Díez, Pilar; Joffre, Richard

2009-09-01

In all Mediterranean-type ecosystems, evergreen and deciduous trees differing in wood anatomy, growth pattern and leaf habit coexist, suggesting distinct adaptative responses to environmental constraints. This study examined the effects of summer water stress on carbon (C) storage and growth in seedlings of three coexisting Mediterranean trees that differed in phenology and wood anatomy characteristics: Quercus ilex subsp. ballota (Desf.) Samp., Quercus faginea Lam. and Pinus halepensis L. Seedlings were subjected to two levels of watering during two consecutive summers and achieved a minimum of -0.5 and -2.5 MPa of predawn water potential in the control and water stress treatment, respectively. Both Quercus species concentrated their growth in the early growing season, demanding higher C in early spring but replenishing C-stores in autumn. These species allocated more biomass to roots, having larger belowground starch and lipid reserves. Quercus species differed in seasonal storage dynamics from P. halepensis. This species allocated most of its C to aboveground growth, which occurred gradually during the growing season, leading to fewer C-reserves. Soluble sugar and starch concentrations sharply declined in August in P. halepensis, probably because reserves support respiration demands as this species closed stomata earlier under water stress. Drought reduced growth of the three species, mainly in Q. faginea and P. halepensis, but not C-reserves, suggesting that growth under water stress conditions is not limited by C-availability.
49 CFR 195.307 - Pressure testing aboveground breakout tanks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... aboveground breakout tanks. (a) For aboveground breakout tanks built into API Specification 12F and first placed in service after October 2, 2000, pneumatic testing must be in accordance with section 5.3 of API Specification 12 F (incorporated by reference, see § 195.3). (b) For aboveground breakout tanks built to API...

49 CFR 195.307 - Pressure testing aboveground breakout tanks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... aboveground breakout tanks. (a) For aboveground breakout tanks built into API Specification 12F and first placed in service after October 2, 2000, pneumatic testing must be in accordance with section 5.3 of API Specification 12 F (incorporated by reference, see § 195.3). (b) For aboveground breakout tanks built to API...
49 CFR 195.307 - Pressure testing aboveground breakout tanks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... aboveground breakout tanks. (a) For aboveground breakout tanks built into API Specification 12F and first placed in service after October 2, 2000, pneumatic testing must be in accordance with section 5.3 of API Specification 12 F (incorporated by reference, see § 195.3). (b) For aboveground breakout tanks built to API...
49 CFR 195.307 - Pressure testing aboveground breakout tanks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... aboveground breakout tanks. (a) For aboveground breakout tanks built into API Specification 12F and first placed in service after October 2, 2000, pneumatic testing must be in accordance with section 5.3 of API Specification 12 F (incorporated by reference, see § 195.3). (b) For aboveground breakout tanks built to API...
Advancing Understanding of the Role of Belowground Processes in Terrestrial Carbon Sinks trhrough Ground-Penetrating Radar. Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Day, Frank P.

2015-02-06

Coarse roots play a significant role in belowground carbon cycling and will likely play an increasingly crucial role in belowground carbon sequestration as atmospheric CO 2 levels continue to rise, yet they are one of the most difficult ecosystem parameters to quantify. Despite promising results with ground-penetrating radar (GPR) as a nondestructive method of quantifying biomass of coarse roots, this application of GPR is in its infancy and neither the complete potential nor limitations of the technology have been fully evaluated. The primary goals and questions of this study fell into four groups: (1) GPR methods: Can GPR detect changemore » in root biomass over time, differentiate live roots from dead roots, differentiate between coarse roots, fine roots bundled together, and a fine root mat, remain effective with varied soil moisture, and detect shadowed roots (roots hidden below larger roots); (2) CO 2 enrichment study at Kennedy Space Center in Brevard County, Florida: Are there post-fire legacy effects of CO 2 fertilization on plant carbon pools following the end of CO 2application ? (3) Disney Wilderness Study: What is the overall coarse root biomass and potential for belowground carbon storage in a restored longleaf pine flatwoods system? Can GPR effectively quantify coarse roots in soils that are wetter than the previous sites and that have a high percentage of saw palmetto rhizomes present? (4) Can GPR accurately represent root architecture in a three-dimensional model? When the user is familiar with the equipment and software in a setting that minimizes unsuitable conditions, GPR is a relatively precise, non-destructive, useful tool for estimating coarse root biomass. However, there are a number of cautions and guidelines that should be followed to minimize inaccuracies or situations that are untenable for GPR use. GPR appears to be precise as it routinely predicts highly similar values for a given area across multiple scanning events; however, it appears to lack sufficient accuracy at small scales. Knowledge of soil conditions and their effects on GPR wave propagation and reception are paramount for the collection of useful data. Strong familiarity with the software and equipment is both important and necessary for GPR use in estimating coarse root biomass. GPR must be utilized at low soil moisture levels in order to accurately represent existing coarse root structures. Our results from Disney Wilderness Preserve highlight the need for a strong understanding of the limitations of GPR, specifically knowledge of root structures (saw palmetto rhizomes) or environmental factors (low moisture content) that may hinder its application within a given system. The 3D modeling of course roots with GPR appears quite promising, as it has become more accurate and precise as the software has advanced and become more robust, but there is still a need for more precision before it will likely be able to model anything more than simple root systems comprised mostly of large diameter roots. Our results from Kennedy Space Center suggest that there are legacy effects from CO 2 fertilization in the form of more root mass providing a greater capacity for aboveground plant regrowth following fire, even 7 years after treatment ended.« less
Fungi and wind strongly influence the temporal availability of logs in an old-growth spruce forest.

PubMed

Edman, Mattias; Jönsson, Mari; Jonsson, Bengt Gunnar

2007-03-01

Coarse woody debris (CWD) is a key habitat for many species in forest ecosystems. To ensure the long-term survival of such species, forest management regimes must include measures that promote dead wood dynamics similar to those of natural forests. Thus, information on CWD dynamics under natural conditions is required, including data pertaining to the underlying agents of disturbance. This study examines modes of mortality, decay rates, and temporal patterns in the availability of Picea abies logs in a Swedish old-growth forest affected by internal, small-scale disturbance. All 684 logs in a 6.6-ha plot were mapped and classified into one of six decay classes. Logs in the early stages of decay were examined for the presence of heart-rot fungi. Six years later all logs were re-inventoried, including newly formed logs. Matrix models based on the transition rates between decay classes showed that it took about 60 years for 90% of the logs to decay beyond class 6 (a deformed trunk with soft wood). Large logs (> 26 cm) decayed 40% more slowly than small logs (< 25 cm). The initial volume of logs was 37.6 m3/ha but increased to 44.8 m3/ha after six years. In addition, there was a large shift in the decay-class distribution. The volume of logs in early and late decay classes increased by 71% and 45%, respectively, while the volume of logs in the intermediate decay classes decreased by 32%. The fluctuations appear to result from pulses in mortality, driven by a combination of strong winds and the heart-rot fungus, Phellinus chrysoloma, which was present in more than 30% of all logs at an early stage of decay. These results show that large temporal fluctuations in dead wood also occur in the absence of large-scale disturbance, and that heart-rot fungi are important factors driving the overall dynamics of dead wood. Since many wood-inhabiting species are naturally rare and have very specific substrate demands, such temporal variability in dead wood availability may have effects on biodiversity and should be taken into account when designing small, protected forest areas.
Physical and chemical characterization of fly ashes from Swiss waste incineration plants and determination of the ash fraction in the nanometer range.

PubMed

Buha, Jelena; Mueller, Nicole; Nowack, Bernd; Ulrich, Andrea; Losert, Sabrina; Wang, Jing

2014-05-06

Waste incineration had been identified as an important source of ultrafine air pollutants resulting in elaborated treatment systems for exhaust air. Nowadays, these systems are able to remove almost all ultrafine particles. However, the fate of ultrafine particles caught in the filters has received little attention so far. Based on the use of engineered nano-objects (ENO) and their transfer into the waste stream, it can be expected that not only combustion generated nanoparticles are found in fly ashes but that many ENO finally end up in this matrix. A more detailed characterization of the nanoparticulate fraction of fly ashes is therefore needed. Physical and chemical characterizations were performed for fly ashes from five selected waste incineration plants (WIPs) with different input materials such as municipal waste, wood and sewage sludge. The intrinsic densities of the fly ashes were in the range of 2.7-3.2 g/cm(3). When the fly ash particle became airborne, the effective density depended on the particle size, increasing from 0.7-0.8 g/cm(3) for 100-150 nm to 2 g/cm(3) for 350-500 nm. The fly ash samples were fractionated at 2 μm, yielding fine fractions (<2 μm) and coarse fractions (>2 μm). The size distributions of the fine fractions in the airborne form were further characterized, which allowed calculation of the percentage of the fly ash particles below 100 nm. We found the highest mass-based percentage was about 0.07%; the number percentage in the fine fraction was in the range of 4.8% to 22%. Comparison with modeling results showed that ENO may constitute a considerable part of the fly ash particles below 100 nm. Chemical analyses showed that for the municipal waste samples Ca and Al were present in higher concentrations in the coarse fraction; for the mixed wood and sludge sample the P concentration was higher in the coarse fraction; for most other samples and elements they were enriched in the fine fraction. Electron microscopic images of fly ashes showed a wide range of particle sizes, from nanometer range to micrometer range. Many aggregated particles were observed, demonstrating that ENO, bulk-derived nano-objects and combustion-generated nano-objects can form aggregates in the incineration process.
Temperate forest fragments maintain aboveground carbon stocks out to the forest edge despite changes in community composition.

PubMed

Ziter, Carly; Bennett, Elena M; Gonzalez, Andrew

2014-11-01

Edge effects are among the primary mechanisms by which forest fragmentation can influence the link between biodiversity and ecosystem processes, but relatively few studies have quantified these mechanisms in temperate regions. Carbon storage is an important ecosystem function altered by edge effects, with implications for climate change mitigation. Two opposing hypotheses suggest that aboveground carbon (AGC) stocks at the forest edge will (a) decrease due to increased tree mortality and compositional shifts towards smaller, lower wood density species (e.g., as seen in tropical systems) or, less often, (b) increase due to light/temperature-induced increases in diversity and productivity. We used field-based measurements, allometry, and mixed models to investigate the effects of proximity to the forest edge on AGC stocks, species richness, and community composition in 24 forest fragments in southern Quebec. We also asked whether fragment size or connectivity with surrounding forests altered these edge effects. AGC stocks remained constant across a 100 m edge-to-interior gradient in all fragment types, despite changes in tree community composition and stem density consistent with expectations of forest edge effects. We attribute this constancy primarily to compensatory effects of small trees at the forest edge; however, it is due in some cases to the retention of large trees at forest edges, likely a result of forest management. Our results suggest important differences between temperate and tropical fragments with respect to mechanisms linking biodiversity and AGC dynamics. Small temperate forest fragments may be valuable in conservation efforts based on maintaining biodiversity and multiple ecosystem services.
Deadwood biomass: an underestimated carbon stock in degraded tropical forests?

NASA Astrophysics Data System (ADS)

Pfeifer, Marion; Lefebvre, Veronique; Turner, Edgar; Cusack, Jeremy; Khoo, MinSheng; Chey, Vun K.; Peni, Maria; Ewers, Robert M.

2015-04-01

Despite a large increase in the area of selectively logged tropical forest worldwide, the carbon stored in deadwood across a tropical forest degradation gradient at the landscape scale remains poorly documented. Many carbon stock studies have either focused exclusively on live standing biomass or have been carried out in primary forests that are unaffected by logging, despite the fact that coarse woody debris (deadwood with ≥10 cm diameter) can contain significant portions of a forest’s carbon stock. We used a field-based assessment to quantify how the relative contribution of deadwood to total above-ground carbon stock changes across a disturbance gradient, from unlogged old-growth forest to severely degraded twice-logged forest, to oil palm plantation. We measured in 193 vegetation plots (25 × 25 m), equating to a survey area of >12 ha of tropical humid forest located within the Stability of Altered Forest Ecosystems Project area, in Sabah, Malaysia. Our results indicate that significant amounts of carbon are stored in deadwood across forest stands. Live tree carbon storage decreased exponentially with increasing forest degradation 7-10 years after logging while deadwood accounted for >50% of above-ground carbon stocks in salvage-logged forest stands, more than twice the proportion commonly assumed in the literature. This carbon will be released as decomposition proceeds. Given the high rates of deforestation and degradation presently occurring in Southeast Asia, our findings have important implications for the calculation of current carbon stocks and sources as a result of human-modification of tropical forests. Assuming similar patterns are prevalent throughout the tropics, our data may indicate a significant global challenge to calculating global carbon fluxes, as selectively-logged forests now represent more than one third of all standing tropical humid forests worldwide.
Can niche plasticity promote biodiversity-productivity relationships through increased complementarity?

PubMed

Niklaus, Pascal A; Baruffol, Martin; He, Jin-Sheng; Ma, Keping; Schmid, Bernhard

2017-04-01

Most experimental biodiversity-ecosystem functioning research to date has addressed herbaceous plant communities. Comparably little is known about how forest communities will respond to species losses, despite their importance for global biogeochemical cycling. We studied tree species interactions in experimental subtropical tree communities with 33 distinct tree species mixtures and one, two, or four species. Plots were either exposed to natural light levels or shaded. Trees grew rapidly and were intensely competing above ground after 1.5 growing seasons when plots were thinned and the vertical distribution of leaves and wood determined by separating the biomass of harvested trees into 50 cm height increments. Our aim was to analyze effects of species richness in relation to the vertical allocation of leaf biomass and wood, with an emphasis on bipartite competitive interactions among species. Aboveground productivity increased with species richness. The community-level vertical leaf and wood distribution depended on the species composition of communities. Mean height and breadth of species-level vertical leaf and wood distributions did not change with species richness. However, the extra biomass produced by mixtures compared to monocultures of the component species increased when vertical leaf distributions of monocultures were more different. Decomposition of biodiversity effects with the additive partitioning scheme indicated positive complementarity effects that were higher in light than in shade. Selection effects did not deviate from zero, irrespective of light levels. Vertical leaf distributions shifted apart in mixed stands as consequence of competition-driven phenotypic plasticity, promoting realized complementarity. Structural equation models showed that this effect was larger for species that differed more in growth strategies that were characterized by functional traits. In 13 of the 18 investigated two-species mixtures, both species benefitted relative to intraspecific competition in monoculture. In the remaining five pairwise mixtures, the relative yield gain of one species exceeded the relative yield loss of the other species, resulting in a relative yield total (RYT) exceeding 1. Overall, our analysis indicates that richness-productivity relationships are promoted by interspecific niche complementarity at early stages of stand development, and that this effect is enhanced by architectural plasticity. © 2017 by the Ecological Society of America.
Modeling Above-Ground Biomass Across Multiple Circum-Arctic Tundra Sites Using High Spatial Resolution Remote Sensing

NASA Astrophysics Data System (ADS)

Räsänen, Aleksi; Juutinen, Sari; Aurela, Mika; Virtanen, Tarmo

2017-04-01

Biomass is one of the central bio-geophysical variables in Earth observation for tracking plant productivity, and flow of carbon, nutrients, and water. Most of the satellite based biomass mapping exercises in Arctic environments have been performed by using rather coarse spatial resolution data, e.g. Landsat and AVHRR which have spatial resolutions of 30 m and >1 km, respectively. While the coarse resolution images have high temporal resolution, they are incapable of capturing the fragmented nature of tundra environment and fine-scale changes in vegetation and carbon exchange patterns. Very high spatial resolution (VHSR, spatial resolution 0.5-2 m) satellite images have the potential to detect environmental variables with an ecologically sound spatial resolution. The usage of VHSR images has, nevertheless, been modest so far in biomass modeling in the Arctic. Our objectives were to use VHSR for predicting above ground biomass in tundra landscapes, evaluate whether a common predictive model can be applied across circum-Arctic tundra and peatland sites having different types of vegetation, and produce knowledge on distribution of plant functional types (PFT) in these sites. Such model development is dependent on ground-based surveys of vegetation with the same spatial resolution and extent with the VHSR images. In this study, we conducted ground-based surveys of vegetation composition and biomass in four different arctic tundra or peatland areas located in Russia, Canada, and Finland. First, we sorted species into PFTs and developed PFT-specific models to predict biomass on the basis of non-destructive measurements (cover, height). Second, we predicted overall biomass on landscape scale by combinations of single bands and vegetation indices of very high resolution satellite images (QuickBird or WorldView-2 images of the eight sites). We compared area-specific empirical regression models and common models that were applied across all sites. We found that NDVI was usually the highest scoring spectral indices in explaining biomass distribution with good explanatory power. Furthermore, models which had more than one explanatory variable had higher explanatory power than models with a single index. The dissimilarity between common and site-specific model estimates was, however, high and data indicates that variation in vegetation properties and its impact on spectral reflectance needs to be acknowledged. Our work produced knowledge on above-ground biomass distribution and contribution of PFTs across circum-Arctic low-growth landscapes and will contribute to developing space-borne vegetation monitoring schemes utilizing VHSR satellite images.
Facilitation and inhibition: changes in plant nitrogen and secondary metabolites mediate interactions between above-ground and below-ground herbivores.

PubMed

Huang, Wei; Siemann, Evan; Yang, Xuefang; Wheeler, Gregory S; Ding, Jianqing

2013-09-22

To date, it remains unclear how herbivore-induced changes in plant primary and secondary metabolites impact above-ground and below-ground herbivore interactions. Here, we report effects of above-ground (adult) and below-ground (larval) feeding by Bikasha collaris on nitrogen and secondary chemicals in shoots and roots of Triadica sebifera to explain reciprocal above-ground and below-ground insect interactions. Plants increased root tannins with below-ground herbivory, but above-ground herbivory prevented this increase and larval survival doubled. Above-ground herbivory elevated root nitrogen, probably contributing to increased larval survival. However, plants increased foliar tannins with above-ground herbivory and below-ground herbivory amplified this increase, and adult survival decreased. As either foliar or root tannins increased, foliar flavonoids decreased, suggesting a trade-off between these chemicals. Together, these results show that plant chemicals mediate contrasting effects of conspecific larval and adult insects, whereas insects may take advantage of plant responses to facilitate their offspring performance, which may influence population dynamics.
Quantification of forest carbon degradation in Nicaragua using RapidEye remote sensing data: El Cuá and Wiwili case studies

NASA Astrophysics Data System (ADS)

Argoty, F. N.; Cifuentes, M.; Imbach, P. A.; Vilchez, S.; Casanoves, F.; Ibrahim, M.; Vierling, L. A.

2012-12-01

Forest degradation and deforestation affect ecosystem function and climate regulation services such as carbon storage. Historically, Central America has been a deforestation and forest degradation hotspot. Wiwili and El Cuá municipalities in northern Nicaragua are no exception, where subsistence agriculture and cattle ranch expansion have driven deforestation and other wood extraction activities, leading to various levels of forest degradation. Reduction of Emissions from forest Degradation and Deforestation (REDD) projects are proposed as a tool to slow the degradation and loss of carbon stocks by restoring carbon to its natural levels in order to mitigate carbon dioxide emissions that cause global warming. REDD projects require baseline estimations of current carbon stocks and forest degradation status. We estimated carbon stocks across a forest degradation gradient based on common biophysical variables and commercially available (RapidEye) remote sensing data. We measured 80 temporary forest plots (50x20m) for aboveground biomass to sample a gradient of forest degradation at two municipalities (El Cuá and Wiwili) in northern Nicaragua. We measured biomass in trees (≥10 cm DBH), saplings (5-9.9 cm DBH), other growth forms (ferns, palms and woody vines), and large detritus (snags and downed wood). Biomass was estimated by a range of allometric models and a constant conversion factor (0.47) was applied to calculate aboveground carbon stocks. Remote sensing data from a RapidEye scene for 02/2010 provided data for 5 spectral bands and 19 vegetation indexes at 6 m spatial resolution. Precipitation, temperature, altitude, slope, canopy cover, and aspect were also used as input variables for carbon modeling. We tested linear mixed models, generalized additive mixed models and regression tree approaches to explain carbon stocks based on vegetation indexes and biophysical variables. Additionally, we grouped plots into low (17-168 Mg C ha-1), medium (168-302 Mg C ha-1) and high (302-418 Mg C ha-1) carbon stocks (with conglomerate analysis) to test for a categorical classification approach based on discriminant analysis. Results show a gradient of total aboveground carbon between 17.78 - 379.2 Mg C ha-1. Models predicting carbon stock had an R2 that ranged between 0.32-0.52 (p<0.0001) across the three methods evaluated. Linear mixed models using the MCARI-MTVI2 vegetation index, based on the red-edge band (690-730 nm), showed the best performance. Categorical classification showed improved performance, with a 17% mean classification error, using 20 predictors (MCARI-MTVI2 was the most important). Our results show the importance of the red-edge band and the potential of multi-spectral high-resolution imagery to quantify tropical forest degradation. Although model performance for prediction of continuous biomass values is somewhat constrained, there is potential for coarser applications in the context of developing REDD baselines and monitoring using categorical mapping of forest degradation (with a trade-off in inference power) by means of relatively low-cost remote sensing and ancillary data.
NGEE Arctic Plant Traits: Plant Biomass and Traits, Kougarok Road Mile Marker 64, Seward Peninsula, Alaska, beginning 2016

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verity Salmon; Colleen Iversen; Amy Breen

Data includes aboveground biomass and plant traits for destructive harvests performed at the Kougarok hill slope located at Kougarok Road, Mile Marker 64. Data collection began in July 2016. Aboveground biomass and aboveground plant traits are available for shrub and understory species found in vegetation plots. Paired observations of aboveground and belowground plant traits are available for select shrub species.
[Spatial distribution of aboveground biomass of shrubs in Tianlaochi catchment of the Qilian Mountains].

PubMed

Liang, Bei; Di, Li; Zhao, Chuan-Yan; Peng, Shou-Zhang; Peng, Huan-Hua; Wang, Chao

2014-02-01

This study estimated the spatial distribution of the aboveground biomass of shrubs in the Tianlaochi catchment of Qilian Mountains based on the field survey and remote sensing data. A relationship model of the aboveground biomass and its feasibly measured factors (i. e. , canopy perimeter and plant height) was built. The land use was classified by object-oriented technique with the high resolution image (GeoEye-1) of the study area, and the distribution of shrub coverage was extracted. Then the total aboveground biomass of shrubs in the study area was estimated by the relationship model with the distribution of shrub coverage. The results showed that the aboveground biomass of shrubs in the study area was 1.8 x 10(3) t and the aboveground biomass per unit area was 1598.45 kg x m(-2). The distribution of shrubs mainly was at altitudes of 3000-3700 m, and the aboveground biomass of shrubs on the sunny slope (1.15 x 10(3) t) was higher than that on the shady slope (0.65 x 10(3) t).
Facilitation and inhibition: changes in plant nitrogen and secondary metabolites mediate interactions between above-ground and below-ground herbivores

PubMed Central

Huang, Wei; Siemann, Evan; Yang, Xuefang; Wheeler, Gregory S.; Ding, Jianqing

2013-01-01

To date, it remains unclear how herbivore-induced changes in plant primary and secondary metabolites impact above-ground and below-ground herbivore interactions. Here, we report effects of above-ground (adult) and below-ground (larval) feeding by Bikasha collaris on nitrogen and secondary chemicals in shoots and roots of Triadica sebifera to explain reciprocal above-ground and below-ground insect interactions. Plants increased root tannins with below-ground herbivory, but above-ground herbivory prevented this increase and larval survival doubled. Above-ground herbivory elevated root nitrogen, probably contributing to increased larval survival. However, plants increased foliar tannins with above-ground herbivory and below-ground herbivory amplified this increase, and adult survival decreased. As either foliar or root tannins increased, foliar flavonoids decreased, suggesting a trade-off between these chemicals. Together, these results show that plant chemicals mediate contrasting effects of conspecific larval and adult insects, whereas insects may take advantage of plant responses to facilitate their offspring performance, which may influence population dynamics. PMID:23902902
Wood-inhabiting fungi in southern Italy forest stands: morphogroups, vegetation types and decay classes.

PubMed

Granito, Vito Mario; Lunghini, Dario; Maggi, Oriana; Persiani, Anna Maria

2015-01-01

The authors conducted an ecological study of forests subjected to varying management. The aim of the study was to extend and integrate, within a multivariate context, knowledge of how saproxylic fungal communities behave along altitudinal/vegetational gradients in response to the varying features and quality of coarse woody debris (CWD). The intra-annual seasonal monitoring of saproxylic fungi, based on sporocarp inventories, was used to investigate saproxylic fungi in relation to vegetation types and management categories. We analyzed fungal species occurrence, recorded according to the presence/absence and frequency of sporocarps, on the basis of the harvest season, of coarse woody debris decay classes as well as other environmental and ecological variables. Two-way cluster analysis, DCA and Spearman's rank correlations, for indirect gradient analysis, were performed to identify any patterns of seasonality and decay. Most of the species were found on CWD in an intermediate decay stage. The first DCA axis revealed the vegetational/microclimate gradient as the main driver of fungal community composition, while the second axis corresponded to a strong gradient of CWD decay classes. © 2015 by The Mycological Society of America.
SRWC bioenergy productivity and economic feasibility on marginal lands.

PubMed

Ghezehei, Solomon B; Shifflett, Shawn D; Hazel, Dennis W; Nichols, Elizabeth Guthrie

2015-09-01

Evolving bioenergy markets necessitate consideration of marginal lands for woody biomass production worldwide particularly the southeastern U.S., a prominent wood pellet exporter to Europe. Growing short rotation woody crops (SRWCs) on marginal lands minimizes concerns about using croplands for bioenergy production and reinforces sustainability of wood supply to existing and growing global biomass markets. We estimated mean annual aboveground green biomass increments (MAIs) and assessed economic feasibility of various operationally established (0.5 ha-109 ha) SRWC stands on lands used to mitigate environmental liabilities of municipal wastewater, livestock wastewater and sludge, and subsurface contamination by petroleum and pesticides. MAIs (Mg ha(-1) yr(-1)) had no consistent relationship with stand density or age. Non-irrigated Populus, Plantanus occidentalis L. and Pinus taeda L. stands produced 2.4-12.4 Mg ha(-1) yr(-1). Older, irrigated Taxodium distchum L., Fraxinus pennsylvanica L., and coppiced P. occidentalis stands had higher MAIs (10.6-21.3 Mg ha(-1) yr(-1)) than irrigated Liquidambar styraciflua L. and non-coppiced, irrigated P. occidentalis (8-18 Mg ha(-1) yr(-1)). Natural hardwood MAIs at 20-60 years were less than hardwood and P. taeda productivities at 5-20 years. Unlike weed control, irrigation and coppicing improved managed hardwood productivity. Rotation length affected economic outcomes although the returns were poor due to high establishment and maintenance costs, low productivities and low current stumpage values, which are expected to quickly change with development of robust global markets. Copyright © 2015 Elsevier Ltd. All rights reserved.
Potential environmental benefits from woodfuel transitions in Haiti: Geospatial scenarios to 2027

NASA Astrophysics Data System (ADS)

Ghilardi, Adrian; Tarter, Andrew; Bailis, Robert

2018-03-01

Woodfuels constitute nearly 80% of Haiti’s primary energy supply. Forests are severely degraded and the nation has long been considered an archetypal case of woodfuel-driven deforestation. However, there is little empirical evidence that woodfuel demand directly contributes to deforestation, but may contribute to degradation. We use MoFuSS (Modeling Fuelwood Sustainability Scenarios), a dynamic landscape model, to assess whether current woodfuel demand is as impactful as it is often depicted by simulating changes in land cover that would result if current demand continues unabated. We also simulate several near-term interventions focused on woodfuel demand reduction to analyze the land cover impacts of different energy trajectories. We find that current demand may contribute to moderate levels of degradation, but it is not as severe as is typically portrayed. Under a business-as-usual scenario, the simulated regenerative capacity of woody biomass is insufficient to meet Haiti’s increasing demand for wood energy and, as a result, between 2017 and 2027 stocks of above-ground (woody) biomass could decline by 4% ± 1%. This is an annual loss of 302 ± 29 kton of wood and would emit 555 ± 54 kton CO2 yr-1. Aggressive interventions to reduce woodfuel demand could slow or even reverse woodfuel-driven degradation, allowing woody biomass to recover in some regions. We discuss the policy implications and propose steps to reduce uncertainty and validate the model.
Invader partitions ecological and evolutionary responses to above- and belowground herbivory.

PubMed

Huang, Wei; Carrillo, Juli; Ding, Jianqing; Siemann, Evan

2012-11-01

Interactions between above- and belowground herbivory may, affect plant performance and structure communities. Though many studies have documented interactions of invasive plants and.herbivores, none shows how above- and belowground herbivores interact to affect invasive plant performance. Here, in a common garden in China, we subjected genetically differentiated tallow trees (Triadica sebifera) from native (China) and invaded (United States) ranges to herbivory by aboveground adults and belowground larvae of a specialist beetle, Bikasha collaris. Overall, relative to plants from China, U.S. plants had greater total and aboveground mass, comparable belowground mass, lower resistance to both above- and belowground herbivory, and higher tolerance to aboveground herbivory only. Accordingly, aboveground adults had greater impacts on Chinese plants, but belowground larvae more strongly impacted U.S. plants. These results indicate that the invader may adopt an "aboveground first" strategy, allocating more resources aboveground in response to selection for increased competitive ability, which increases aboveground tolerance to herbivory. Furthermore, we found that adults facilitated larval success, and these feedbacks were stronger for U.S. plants, suggesting that aboveground feeding of adults may be associated with lower defenses and/or higher resources belowground in the invader. Therefore, plants may have evolved different responses to above- and belowground herbivory, which can affect invasion success and herbivore population dynamics. These findings may provide new insights for an effective biological control program against invasive plants.
Modeling aboveground biomass of Tamarix ramosissima in the Arkansas River Basin of Southeastern Colorado, USA

USGS Publications Warehouse

Evangelista, P.; Kumar, S.; Stohlgren, T.J.; Crall, A.W.; Newman, G.J.

2007-01-01

Predictive models of aboveground biomass of nonnative Tamarix ramosissima of various sizes were developed using destructive sampling techniques on 50 individuals and four 100-m2 plots. Each sample was measured for average height (m) of stems and canopy area (m2) prior to cutting, drying, and weighing. Five competing regression models (P < 0.05) were developed to estimate aboveground biomass of T. ramosissima using average height and/or canopy area measurements and were evaluated using Akaike's Information Criterion corrected for small sample size (AICc). Our best model (AICc = -148.69, ??AICc = 0) successfully predicted T. ramosissima aboveground biomass (R2 = 0.97) and used average height and canopy area as predictors. Our 2nd-best model, using the same predictors, was also successful in predicting aboveground biomass (R2 = 0.97, AICc = -131.71, ??AICc = 16.98). A 3rd model demonstrated high correlation between only aboveground biomass and canopy area (R2 = 0.95), while 2 additional models found high correlations between aboveground biomass and average height measurements only (R2 = 0.90 and 0.70, respectively). These models illustrate how simple field measurements, such as height and canopy area, can be used in allometric relationships to accurately predict aboveground biomass of T. ramosissima. Although a correction factor may be necessary for predictions at larger scales, the models presented will prove useful for many research and management initiatives.

Predicting the ash behavior during biomass combustion in FBC conditions by combining advanced fuel analyses with thermodynamic multicomponent equilibrium calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skrifvars, B.J.; Blomquist, J.P.; Hupa, M.

1998-12-31

Previous work at Aabo Akademi University has focused on identification and quantification of various sintering mechanisms which are relevant for problematic ash behavior during biomass combustion in fluidized bed combustion conditions, and on multi-component multi-phase thermodynamic phase equilibrium calculations of ash chemistry in these conditions. In both areas new information has been developed and useful modeling capabilities have been created. Based on the previous work, the authors now present a novel approach of using a combination of an advanced fuel analysis method and thermodynamic phase equilibrium calculations to predict the chemical and thermal behavior of the ash when firing biomass.more » Four different fuels [coal, forest residues, wood chips, and a mixture of forest residue and wood chips] were analyzed using the chemical fractionation analysis technique. Based on the results from these analyses, the authors formed two different ash fractions, (1) one fine sized fraction consisting of those elements found in the water and weak acid leach, and (2) a coarse ash particle fraction consisting of those elements found in the strong acid leach and non-leachable rest. The small sized ash fraction was then assumed to be carried up with the flue gases and consequently formed the base for any ash related problems in the flue gas channel. This fraction was therefore analyzed on its chemical and thermal behavior using multi-component multi-phase equilibrium calculations, by which the composition and the melting behavior was estimated as a function of the temperature. The amount of melt, which has earlier been found to be strongly related to problematic ash behavior, was finally expressed as a function of the temperature for the fraction. The coarse fraction was treated separately. Here the authors estimate the composition only. The paper discusses the results and their relevance to full scale combustion.« less
Improved passive treatment of high Zn and Mn concentrations using caustic magnesia (MgO): particle size effects.

PubMed

Rötting, Tobias S; Ayora, Carlos; Carrera, Jesus

2008-12-15

High concentrations of divalent metals such as Zn, Mn, Cu, Pb, Ni, Cd, Co, etc. are not removed satisfactorily in conventional (calcite- or organic matter-based) passive treatment systems. Caustic magnesia ("MgO") has been used successfully as an alternative alkaline material to remove these metals almost completely from water, but columns with coarse-grained MgO lost reactivity or permeability due to the accumulation of precipitates when only a small portion of the reagent had been spent. In the present study, MgO was mixed with wood chips to overcome these problems. Two columns with different MgO grain sizes were used to treat Zn- and Mn-rich water during one year. Performance was compared by measuring depth profiles of chemical parameters and hydraulic conductivity. The column containing 25% (v/v) of MgO with median particle size of about 3 mm displayed low reactivity and poor metal retention. In contrast, the column containing only 12.5% (v/v) of MgO with median particle size of 0.15 mm depleted Zn and Mn below detection limit throughout the study and had a good hydraulic performance. 95% of the applied MgO was consumed in the zone where Zn and Mn accumulated. The fine alkaline grains can dissolve almost completely before the growing layer of precipitates passivates them, whereas clogging is prevented by the large pores of the coarse inert matrix (wood chips). A reactive transport model corroborated the hypotheses that Zn(II) was removed due to its low solubility at pH near 10 achieved by MgO dissolution, whereas Mn(II) was removed due to rapid oxidation to Mn(III) at this pH and subsequent precipitation. The model also confirmed that the small size and large specific surface area of the MgO particles are the key factor to achieve a sufficiently fast dissolution.
Action Memorandum for Decommissioning of TAN-607 Hot Shop Area

DOE Office of Scientific and Technical Information (OSTI.GOV)

M. A. Pinzel

The Department of Energy is documenting the selection of an alternative for the TAN-607 Hot Shop Area using a Comprehensive Environmental Response, Compensation, and Liability Act non-time-critical removal action (NTCRA). The scope of the removal action is limited to TAN-607 Hot Shop Area. An engineering evaluation/cost analysis (EE/CA) has assisted the Department of Energy Idaho Operations Office in identifuomg the most effective method for performing the decommissioning of this structure whose mission has ended. TAN-607 Hot Shop Area is located at Test Area North Technical Support Facility within the Idaho National Laboratory Site. The selected alternative consists of demolishing themore » TAN-607 aboveground structures and components, removing belowground noninert components (e.g. wood products), and removing the radiologically contaminated debris that does not meet remedial action objectives (RAOs), as defined in the Record of Decision Amendment for the V-Tanks and Explanation of Significant Differences for the PM-2A Tanks at Test Area North, Operable Unit 1-10.« less
Sensitivity of tropical forest aboveground productivity to climate anomalies in SW Costa Rica

NASA Astrophysics Data System (ADS)

Hofhansl, Florian; Kobler, Johannes; Ofner, Joachim; Drage, Sigrid; Pölz, Eva-Maria; Wanek, Wolfgang

2014-12-01

The productivity of tropical forests is driven by climate (precipitation, temperature, and light) and soil fertility (geology and topography). While large-scale drivers of tropical productivity are well established, knowledge on the sensitivity of tropical lowland net primary production to climate anomalies remains scarce. We here analyze seven consecutive years of monthly recorded tropical forest aboveground net primary production (ANPP) in response to a recent El Niño-Southern Oscillation (ENSO) anomaly. The ENSO transition period resulted in increased temperatures and decreased precipitation during the El Niño dry period, causing a decrease in ANPP. However, the subsequent La Niña wet period caused strong increases in ANPP such that drought-induced reductions were overcompensated. Most strikingly, the climatic controls differed between canopy production (CP) and wood production (WP). Whereas CP showed strong seasonal variation but was not affected by ENSO, WP decreased significantly in response to a 3°C increase in annual maximum temperatures during the El Niño period but subsequently recovered to above predrought levels during the La Niña period. Moreover, the climate sensitivity of tropical forest ANPP components was affected by local topography (water availability) and disturbance history (species composition). Our results suggest that projected increases in temperature and dry season length could impact tropical carbon sequestration by shifting ANPP partitioning toward decreased WP, thus decreasing the carbon storage of highly productive lowland forests. We conclude that the impact of climate anomalies on tropical forest productivity is strongly related to local site characteristics and will therefore likely prevent uniform responses of tropical lowland forests to projected global changes.
Net primary production and phenology on a southern Appalachian watershed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Day, F.P. Jr.; Monk, C.D.

1977-01-01

Net primary production (NPP) is an important function of plant communities which has not often been examined seasonally in a forested ecosystem. The major objective of the study was to measure above-ground NPP seasonally and relate it to phenological activity on a hardwood forest watershed at Coweeta Hydrologic Laboratory, North Carolina. NPP was estimated as the increase in biomass, estimated from regression equations on diameter. Diameter increases were measured by venier tree bands. Phenological observations were made on bud break, leaf emergence, flowering, mature fruit, leaf senescence, and leaf fall. The species studied intensively were Acer rubrum, Quercus prinus, Caryamore » glabra, Cornus florida, and Liriodendron tulipifera. Liriodendron was found to be the most productive species per individual, but Quercus prinus was the most productive per unit ground area. The total watershed estimate of aboveground NPP was 8,754 kg ha/sup -1/yr/sup -1/ and included 47.9 percent leaves, 33.2 percent wood, 7.8 percent bark, 4.8 percent reproductive tissues, 4.2 percent loss to consumers, and 2.1 percent twigs. Increases in leaf biomass were most rapid in the spring, but woody tissue production peaked in June and continued through August. Since leaf production peaked in the spring, the plants' photosynthetic machinery was activated early in the growing season to support woody tissue production, which followed the period of rapid leaf growth, and reproductive activity. Flowering occurred during the leaf expansion period except for Acer rubrum, which flowered before leaf emergence. Fruit maturation occurred during late summer to early fall, when there were no additional biomass increases. Acer rubrum was an exception as its fruit matured during the period of leaf expansion.« less
Net primary production and phenology on a southern Appalachian watershed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Day, F.P. Jr.; Monk, C.D.

1977-10-01

Net primary production (NPP) is an important function of plant communities which has not often been examined seasonally in a forested ecosystem. The major objective of the study was to measure above-ground NPP seasonally and relate it to phenological activity on a hardwood forest watershed at Coweeta Hydrologic Laboratory, North Carolina. NPP was estimated as the increase in biomass, estimated from regression equations on diameter. Diameter increases were measured by vernier tree bands. Phenological observations were made on bud break, leaf emergence, flowering, mature fruit, leaf senescence, and leaf fall. The species studied intensively were Acer rubrum, Quercus prinus, Caryamore » glabra, Cornus florida, and Liriodendron tulipifera. Liriodendron was found to be the most productive species per individual, but Quercus prinus was the most productive per unit ground area. The total watershed estimate of aboveground NPP was 8,754 kg ha/sup -1/ yr/sup -1/ and included 47.9% leaves, 33.2% wood, 7.8% bark, 4.8% reproductive tissues, 4.2% loss to consumers, and 2.1% twigs. Increases in leaf biomass were most rapid in the spring, but woody tissue production peaked in June and continued through August. Since leaf production peaked in the spring, the plants' photosynthetic machinery was activated early in the growing season to support woody tissue production, which followed the period of rapid leaf growth, and reproductive activity. Flowering ocurred during the leaf expansion period except for Acer rubrum, which flowered before leaf emergence. Fruit maturation occurred during late summer to early fall, when there were no additional biomass increases. Acer rubrum was an exception as its fruit matured during the period of leaf expansion.« less
A methodological framework to assess the carbon balance of tropical managed forests.

PubMed

Piponiot, Camille; Cabon, Antoine; Descroix, Laurent; Dourdain, Aurélie; Mazzei, Lucas; Ouliac, Benjamin; Rutishauser, Ervan; Sist, Plinio; Hérault, Bruno

2016-12-01

Managed forests are a major component of tropical landscapes. Production forests as designated by national forest services cover up to 400 million ha, i.e. half of the forested area in the humid tropics. Forest management thus plays a major role in the global carbon budget, but with a lack of unified method to estimate carbon fluxes from tropical managed forests. In this study we propose a new time- and spatially-explicit methodology to estimate the above-ground carbon budget of selective logging at regional scale. The yearly balance of a logging unit, i.e. the elementary management unit of a forest estate, is modelled by aggregating three sub-models encompassing (i) emissions from extracted wood, (ii) emissions from logging damage and deforested areas and (iii) carbon storage from post-logging recovery. Models are parametrised and uncertainties are propagated through a MCMC algorithm. As a case study, we used 38 years of National Forest Inventories in French Guiana, northeastern Amazonia, to estimate the above-ground carbon balance (i.e. the net carbon exchange with the atmosphere) of selectively logged forests. Over this period, the net carbon balance of selective logging in the French Guianan Permanent Forest Estate is estimated to be comprised between 0.12 and 1.33 Tg C, with a median value of 0.64 Tg C. Uncertainties over the model could be diminished by improving the accuracy of both logging damage and large woody necromass decay submodels. We propose an innovating carbon accounting framework relying upon basic logging statistics. This flexible tool allows carbon budget of tropical managed forests to be estimated in a wide range of tropical regions.
Above-ground sulfur cycling in adjacent coniferous and deciduous forest and watershed sulfur retention in the Georgia Piedmont, U.S.A.

USGS Publications Warehouse

Cappellato, R.; Peters, N.E.; Meyers, T.P.

1998-01-01

Atmospheric deposition and above-ground cycling of sulfur (S) were evaluated in adjacent deciduous and coniferous forests at the Panola Mountain Research Watershed (PMRW), Georgia U.S.A. Total atmospheric S deposition (wet plus dry) was 12.9 and 12.7 kg ha-1 yr-1 for the deciduous and coniferous forests, respectively, from October 1987 through November 1989. Dry deposition contributes more than 40% to the total atmospheric S deposition, and SO2 is the major source (~55%) of total dry S deposition. Dry deposition to these canopies is similar to regional estimates suggesting that 60-km proximity to emission sources does not noticeably impact dry deposition at PMRW. Below-canopy S fluxes (throughfall plus stemflow) in each forest are 37% higher annually in the deciduous forest than in the coniferous forest. An excess in below-canopy S flux in the deciduous forest is attributed to leaching and higher dry deposition than in the coniferous forest. Total S deposition to the forest floor by throughfall, stemflow and litterfall was 2.4 and 2.8 times higher in the deciduous and coniferous forests, respectively, than annual S growth requirement for foliage and wood. Although A deposition exceeds growth requirement, more than 95% of the total atmospheric S deposition was retained by the watershed in 1988 and 1989. The S retention at PMRW is primarily due to SO2+4 adsorption by iron oxides and hydroxides in watershed soils. The S content in while oak and loblolly pine boles have increased more than 200% in the last 20 yr, possibly reflecting increases in emissions.
Individual tree size inequality enhances aboveground biomass in homegarden agroforestry systems in the dry zone of Sri Lanka.

PubMed

Ali, Arshad; Mattsson, Eskil

2017-01-01

Individual tree size variation, which is generally quantified by variances in tree diameter at breast height (DBH) and height in isolation or conjunction, plays a central role in ecosystem functioning in both controlled and natural environments, including forests. However, none of the studies have been conducted in homegarden agroforestry systems. In this study, aboveground biomass, stand quality, cation exchange capacity (CEC), DBH variation, and species diversity were determined across 45 homegardens in the dry zone of Sri Lanka. We employed structural equation modeling (SEM) to test for the direct and indirect effects of stand quality and CEC, via tree size inequality and species diversity, on aboveground biomass. The SEM accounted for 26, 8, and 1% of the variation in aboveground biomass, species diversity and DBH variation, respectively. DBH variation had the strongest positive direct effect on aboveground biomass (β=0.49), followed by the non-significant direct effect of species diversity (β=0.17), stand quality (β=0.17) and CEC (β=-0.05). There were non-significant direct effects of CEC and stand quality on DBH variation and species diversity. Stand quality and CEC had also non-significant indirect effects, via DBH variation and species diversity, on aboveground biomass. Our study revealed that aboveground biomass substantially increased with individual tree size variation only, which supports the niche complementarity mechanism. However, aboveground biomass was not considerably increased with species diversity, stand quality and soil fertility, which might be attributable to the adaptation of certain productive species to the local site conditions. Stand structure shaped by few productive species or independent of species diversity is a main determinant for the variation in aboveground biomass in the studied homegardens. Maintaining stand structure through management practices could be an effective approach for enhancing aboveground biomass in these dry zone homegarden agroforestry systems. Copyright © 2016 Elsevier B.V. All rights reserved.
Effects of hydraulic roughness on surface textures of gravel‐bed rivers

USGS Publications Warehouse

Buffington, John M.; Montgomery, David R.

1999-01-01

Field studies of forest gravel‐bed rivers in northwestern Washington and southeastern Alaska demonstrate that bed‐surface grain size is responsive to hydraulic roughness caused by bank irregularities, bars, and wood debris. We evaluate textural response by comparing reach‐average median grain size (D50) to that predicted from the total bank‐full boundary shear stress (т0bf), representing a hypothetical reference condition of low hydraulic roughness. For a given т0bf, channels with progressively greater hydraulic roughness have systematically finer bed surfaces, presumably due to reduced bed shear stress, resulting in lower channel competence and diminished bed load transport capacity, both of which promote textural fining. In channels with significant hydraulic roughness, observed values D50 can be up to 90% smaller than those predicted from т0bf. We find that wood debris plays an important role at our study sites, not only providing hydraulic roughness but also influencing pool spacing, frequency of textural patches, and the amplitude and wavelength of bank and bar topography and their consequent roughness. Our observations also have biological implications. We find that textural fining due to hydraulic roughness can create usable salmonid spawning gravels in channels that otherwise would be too coarse.
Effects of postfire salvage logging on deadwood-associated beetles.

PubMed

Cobb, T P; Morissette, J L; Jacobs, J M; Koivula, M J; Spence, J R; Langor, D W

2011-02-01

In Canada and the United States pressure to recoup financial costs of wildfire by harvesting burned timber is increasing, despite insufficient understanding of the ecological consequences of postfire salvage logging. We compared the species richness and composition of deadwood-associated beetle assemblages among undisturbed, recently burned, logged, and salvage-logged, boreal, mixed-wood stands. Species richness was lowest in salvage-logged stands, largely due to a negative effect of harvesting on the occurrence of wood- and bark-boring species. In comparison with undisturbed stands, the combination of wildfire and logging in salvage-logged stands had a greater effect on species composition than either disturbance alone. Strong differences in species composition among stand treatments were linked to differences in quantity and quality (e.g., decay stage) of coarse woody debris. We found that the effects of wildfire and logging on deadwood-associated beetles were synergistic, such that the effects of postfire salvage logging could not be predicted reliably on the basis of data on either disturbance alone. Thus, increases in salvage logging of burned forests may have serious negative consequences for deadwood-associated beetles and their ecological functions in early postfire successional forests. ©2010 Society for Conservation Biology.
Burrowing mayfly populations in Chequamegon Bay, Wisconsin: 2002 and 2012

USGS Publications Warehouse

Brunk, Kristin M.; Vinson, Mark R.; Ogle, Derek H.; Evrard, Lori M.

2014-01-01

Burrowing mayflies (Ephemeroptera: Ephemeridae) are sensitive to pollution and have been used as environmental indicators in the Great Lakes. Hexagenia limbata and Ephemera simulans population abundance and biomass estimates from Chequamegon Bay, Lake Superior, were compared between the years 2002 and 2012 as well as inside and outside the Northern States Power Lakefront Superfund site. Mean abundance was similar and mean biomass of Ephemeridae was slightly less in 2012 than in 2002, most likely due to the occurrence of E. simulans in 2012, a smaller species not collected in 2002. In 2012, mean ephemerid abundance and biomass outside the Superfund site was significantly higher than inside the Superfund site. Biomass was higher in clay, clay with sand, and sand with clay substrates than in fine sand, coarse sand, or wood debris substrates. Substrate in the Superfund site was predominantly wood debris. Future monitoring of ephemerid populations in Chequamegon Bay, and particularly in the Superfund site as clean up begins, would be valuable to establish long-term population trends for these two species and potentially shed light on the habitat requirements of E. simulans, an understudied species in the Great Lakes.
Colonization and development of stream communities across a 200-year gradient in Glacier Bay National Park, Alaska

USGS Publications Warehouse

Milner, Alexander M.; Knudsen, E. Eric; Soiseth, Chad; Robertson, Anne L.; Schell, Don; Phillips, Ian T.; Magnusson, Katrina

2000-01-01

In May 1997, physical and biological variables were studied in 16 streams of different ages and contrasting stages of development following glacial recession in Glacier Bay National Park, southeast Alaska. The number of microcrustacean and macroinvertebrate taxa and juvenile fish abundance and diversity were significantly greater in older streams. Microcrustacean diversity was related to the amount of instream wood and percent pool habitat, while the number of macroinvertebrate taxa was related to bed stability, amount of instream wood, and percent pool habitat. The percent contribution of Ephemeroptera to stream benthic communities increased significantly with stream age and the amount of coarse benthic organic matter. Juvenile Dolly Varden (Salvelinus malma) were dominant in the younger streams, but juvenile coho salmon (Oncorhynchus kisutch) abundance was greater in older streams associated with increased pool habitat. Upstream lakes significantly influenced channel stability, percent Chironomidae, total macroinvertebrate and meiofaunal abundance, and percent fish cover. Stable isotope analyses indicated nitrogen enrichment from marine sources in macroinvertebrates and juvenile fish in older streams with established salmon runs. The findings are encapsulated in a conceptual summary of stream development that proposes stream assemblages to be determined by direct interactions with the terrestrial, marine, and lake ecosystems.
Carbon allocation belowground in Pinus pinaster using stable carbon isotope pulse labeling technique

NASA Astrophysics Data System (ADS)

Dannoura, M.; Bosc, A.; Chipeaux, C.; Sartore, M.; Lambrot, C.; Trichet, P.; Bakker, M.; Loustau, D.; Epron, D.

2010-12-01

Carbon allocation belowground competes with aboveground growth and biomass production. In the other hand, it contributes to resource acquisition such as nutrient, water and carbon sequestration in soil. Thus, a better characterization of carbon flow from plant to soil and its residence time within each compartment is an important issue for understanding and modeling forest ecosystem carbon budget. 13C pulse labeling of whole crown was conducted at 4 seasons to study the fate of assimilated carbon by photosynthesis into the root on 12 year old Pinus pinaster planted in the INRA domain of Pierroton. Maritime pine is the most widely planted species in South-West Europe. Stem, root and soil CO2 effluxes and their isotope composition were measured continuously by tunable diode laser absorption spectroscopy with a trace gas analyzer (TGA 100A; Campbell Scientific) coupled to flow-through chambers. 13CO2 recovery and peak were observed in respiration of each compartment after labeling. It appeared sequentially from top of stem to bottom, and to coarse root. The maximum velocity of carbon transfer was calculated as the difference in time lag of recovery between two positions on the trunk or on the root. It ranged between 0.08-0.2 m h-1 in stem and between 0.04-0.12 m h-1 in coarse root. This velocity was higher in warmer season, and the difference between time lag of recovery and peak increased after first frost. Photosynthates arrived underground 1.5 to 5 days after labeling, at similar time in soil CO2 effluxes and coarse root respiration. 0.08-1.4 g of carbon was respired per tree during first 20 days following labeling. It presented 0.6 -10% of 13C used for labeling and it is strongly related to seasons. The isotope signal was detected in fine root organs and microbial biomass by periodical core sampling. The peak was observed 6 days after labeling in early summer while it was delayed more than 10 days in autumn and winter with less amount of carbon allocated belowground.
Responses of plant available water and forest productivity to variably layered coarse textured soils

NASA Astrophysics Data System (ADS)

Huang, Mingbin; Barbour, Lee; Elshorbagy, Amin; Si, Bing; Zettl, Julie

2010-05-01

Reforestation is a primary end use for reconstructed soils following oil sands mining in northern Alberta, Canada. Limited soil water conditions strongly restrict plant growth. Previous research has shown that layering of sandy soils can produce enhanced water availability for plant growth; however, the effect of gradation on these enhancements is not well defined. The objective of this study was to evaluate the effect of soil texture (gradation and layering) on plant available water and consequently on forest productivity for reclaimed coarse textured soils. A previously validated system dynamics (SD) model of soil moisture dynamics was coupled with ecophysiological and biogeochemical processes model, Biome-BGC-SD, to simulate forest dynamics for different soil profiles. These profiles included contrasting 50 cm textural layers of finer sand overlying coarser sand in which the sand layers had either a well graded or uniform soil texture. These profiles were compared to uniform profiles of the same sands. Three tree species of jack pine (Pinus banksiana Lamb.), white spruce (Picea glauce Voss.), and trembling aspen (Populus tremuloides Michx.) were simulated using a 50 year climatic data base from northern Alberta. Available water holding capacity (AWHC) was used to identify soil moisture regime, and leaf area index (LAI) and net primary production (NPP) were used as indices of forest productivity. Published physiological parameters were used in the Biome-BGC-SD model. Relative productivity was assessed by comparing model predictions to the measured above-ground biomass dynamics for the three tree species, and was then used to study the responses of forest leaf area index and potential productivity to AWHC on different soil profiles. Simulated results indicated soil layering could significantly increase AWHC in the 1-m profile for coarse textured soils. This enhanced AWHC could result in an increase in forest LAI and NPP. The increased extent varied with soil textures and vegetative types. The simulated results showed that the presence of 50 cm of coarser graded sand overlying 50 cm of finer graded sand is the most effective reclaimed prescription to increase AWHC and forest productivity among the studied soil profiles.
Wood decay in desert riverine environments

USGS Publications Warehouse

Andersen, Douglas; Stricker, Craig A.; Nelson, S. Mark

2016-01-01

Floodplain forests and the woody debris they produce are major components of riverine ecosystems in many arid and semiarid regions (drylands). We monitored breakdown and nitrogen dynamics in wood and bark from a native riparian tree, Fremont cottonwood (Populus deltoides subsp. wislizeni), along four North American desert streams. We placed locally-obtained, fresh, coarse material [disks or cylinders (∼500–2000 cm3)] along two cold-desert and two warm-desert rivers in the Colorado River Basin. Material was placed in both floodplain and aquatic environments, and left in situ for up to 12 years. We tested the hypothesis that breakdown would be fastest in relatively warm and moist aerobic environments by comparing the time required for 50% loss of initial ash-free dry matter (T50) calculated using exponential decay models incorporating a lag term. In cold-desert sites (Green and Yampa rivers, Colorado), disks of wood with bark attached exposed for up to 12 years in locations rarely inundated lost mass at a slower rate (T50 = 34 yr) than in locations inundated during most spring floods (T50 = 12 yr). At the latter locations, bark alone loss mass at a rate initially similar to whole disks (T50 = 13 yr), but which subsequently slowed. In warm-desert sites monitored for 3 years, cylinders of wood with bark removed lost mass very slowly (T50 = 60 yr) at a location never inundated (Bill Williams River, Arizona), whereas decay rate varied among aquatic locations (T50 = 20 yr in Bill Williams River; T50 = 3 yr in Las Vegas Wash, an effluent-dominated stream warmed by treated wastewater inflows). Invertebrates had a minor role in wood breakdown except at in-stream locations in Las Vegas Wash. The presence and form of change in nitrogen content during exposure varied among riverine environments. Our results suggest woody debris breakdown in desert riverine ecosystems is primarily a microbial process with rates determined by landscape position, local weather, and especially the regional climate through its effect on the flow regime. The increased warmth and aridity expected to accompany climate change in the North American southwest will likely retard the already slow wood decay process on naturally functioning desert river floodplains. Our results have implications for designing environmental flows to manage floodplain forest wood budgets, carbon storage, and nutrient cycling along regulated dryland rivers.
Estimating forest and woodland aboveground biomass using active and passive remote sensing

USGS Publications Warehouse

Wu, Zhuoting; Dye, Dennis G.; Vogel, John M.; Middleton, Barry R.

2016-01-01

Aboveground biomass was estimated from active and passive remote sensing sources, including airborne lidar and Landsat-8 satellites, in an eastern Arizona (USA) study area comprised of forest and woodland ecosystems. Compared to field measurements, airborne lidar enabled direct estimation of individual tree height with a slope of 0.98 (R2 = 0.98). At the plot-level, lidar-derived height and intensity metrics provided the most robust estimate for aboveground biomass, producing dominant species-based aboveground models with errors ranging from 4 to 14Mg ha –1 across all woodland and forest species. Landsat-8 imagery produced dominant species-based aboveground biomass models with errors ranging from 10 to 28 Mg ha –1. Thus, airborne lidar allowed for estimates for fine-scale aboveground biomass mapping with low uncertainty, while Landsat-8 seems best suited for broader spatial scale products such as a national biomass essential climate variable (ECV) based on land cover types for the United States.
Estimating soil organic and aboveground woody carbon stock in a protected dry Miombo ecosystem, Zimbabwe: Landsat 8 OLI data applications

NASA Astrophysics Data System (ADS)

Dube, Timothy; Muchena, Richard; Masocha, Mhosisi; Shoko, Cletah

2018-06-01

Accurate and reliable soil organic carbon stock estimation is critical in understanding forest role to regional carbon cycles. So far, the total carbon pool in dry Miombo ecosystems is often under-estimated. In that regard this study sought to model the relationship between the aboveground woody carbon pool and the soil carbon pool, using both ground-based and remote sensing methods. To achieve this objective, the Ratio Vegetation Index (RVI), Normalized Difference Vegetation Index (NDVI), and the Soil Adjusted Vegetation Index (SAVI) computed from the newly launched Landsat 8 OLI satellite data were used. Correlation and regression analysis were used to relate Soil Organic Carbon (S.O.C), aboveground woody carbon and remotely sensed vegetation indices. Results showed a soil organic carbon in the upper soil layer (0-15 cm) was positively correlated with aboveground woody carbon and this relationship was significant (r = 0.678; P < 0.05) aboveground carbon. However, there were no significant correlations (r = -0.11, P > 0.05) between SOC in the deeper soil layer (15-30 cm) and aboveground woody carbon. These findings imply that (relationship between aboveground woody carbon and S.O.C) aboveground woody carbon stocks can be used as a proxy to estimate S.O.C in the top soil layer (0-15 cm) in dry Miombo ecosystems. Overall, these findings underscore the potential and significance of remote sensing data in understanding savanna ecosystems contribution to the global carbon cycle.
Soil Carbon Budget During Establishment of Short Rotation Woody Crops

NASA Astrophysics Data System (ADS)

Coleman, M. D.

2003-12-01

Carbon budgets were monitored following forest harvest and during re-establishment of short rotation woody crops. Soil CO2 efflux was monitored using infared gas analyzer methods, fine root production was estimated with minirhizotrons, above ground litter inputs were trapped, coarse root inputs were estimated with developed allometric relationships, and soil carbon pools were measured in loblolly pine and cottonwood plantations. Our carbon budget allows evaluation of errors, as well as quantifying pools and fluxes in developing stands during non-steady-state conditions. Soil CO2 efflux was larger than the combined inputs from aboveground litter fall and root production. Fine-root production increased during stand development; however, mortality was not yet equivalent to production, showing the belowground carbon budget was not yet in equilibrium and root carbon standing crop was accruing. Belowground production was greater in cottonwood than pine, but the level of pine soil CO2 efflux was equal to or greater than that of cottonwood, indicating heterotrophic respiration was higher for pine. Comparison of unaccounted efflux with soil organic carbon changes provides verification of loss or accrual.
Phytoremediation trials on metal- and arsenic-contaminated pyrite wastes (Torviscosa, Italy).

PubMed

Vamerali, Teofilo; Bandiera, Marianna; Coletto, Lucia; Zanetti, Federica; Dickinson, Nicholas M; Mosca, Giuliano

2009-03-01

At a site in Udine, Italy, a 0.7m layer of As, Co, Cu, Pb and Zn contaminated wastes derived from mineral roasting for sulphur extraction had been covered with an unpolluted 0.15m layer of gravelly soil. This study investigates whether woody biomass phytoremediation is a realistic management option. Comparing ploughing and subsoiling (0.35m depth), the growth of Populus and Salix and trace element uptake were investigated in both pot and field trials. Species differences were marginal and species selection was not critical. Impaired above-ground productivity and low translocation of trace elements showed that bioavailable contaminant stripping was not feasible. The most significant finding was of coarse and fine roots proliferation in surface layers that provided a significant sink for trace elements. We conclude that phytostabilisation and effective immobilisation of metals and As could be achieved at the site by soil amelioration combined with woody species establishment. Confidence to achieve a long-term and sustainable remediation requires a more complete quantification of root dynamics and a better understanding of rhizosphere processes.

A new conceptual model on the fate and controls of fresh and pyrolized plant litter decomposition

USDA-ARS?s Scientific Manuscript database

The leaching of dissolved organic matter (DOM) from fresh and pyrolyzed aboveground plant inputs to the soil is a major pathway by which decomposing aboveground plant material contributes to soil organic matter formation. Understanding how aboveground plant input chemical traits control the partiti...
Estimating herbaceous biomass of grassland vegetation using the reference unit method

Treesearch

Eric D. Boyda; Jack L. Butler; Lan Xu

2015-01-01

Aboveground net primary production provides valuable information on wildlife habitat, fire fuel loads, and forage availability. Aboveground net primary production in herbaceous plant communities is typically measured by clipping aboveground biomass. However, the high costs associated with physically harvesting plant biomass may prevent collecting sufficient...
Proposal of new convenient extractant for assessing phytoavailability of heavy metals in contaminated sandy soil.

PubMed

Korzeniowska, Jolanta; Stanislawska-Glubiak, Ewa

2017-06-01

The aim of the study was to compare the usefulness of 1 M HCl with aqua regia, EDTA, and CaCl 2 for the extraction of phytoavailable forms of Cu, Ni, and Zn on coarse-textured soils contaminated with these metals. Two microplot experiments were used for the studies. Reed canary grass (Phalaris arundinacea), maize (Zea mays), willow (Salix viminalis), spartina (Spartina pectinata), and miscanthus (Miscanthus × giganteus) were used as test plants. They were grown on soil artificially spiked with Cu, Ni, and Zn. The experimental design included a control and three increasing doses of metals. Microplots (1 m 2 × 1 m deep) were filled with sandy soil (clay-6%, pH 5.5, Corg-0.8%). Metals in the form of sulfates were dissolved in water and applied to the plot using a hand liquid sprayer. During the harvest, samples were collected from aboveground parts, roots, and the soil and then tested for their Cu, Zn, and Ni contents. The metal content of the soil was determined using four tested extractants. It was found that Cu and Ni were accumulated in roots in bigger amounts than Zn. The usefulness of the extractants was evaluated based on the correlation between the content of metals in the soil and the plant (n = 32). This study demonstrated that 1 M HCl, aqua regia, and EDTA were more efficient or equally useful for the assessment of the phytoavailability of Cu, Ni, and Zn as CaCl 2 . Due to the ease of performing determinations and their low cost, 1 M HCl can be recommended to assess the excess of Cu, Ni, and Zn in the coarse-textured soils.
Analysis of biophysical and anthropogenic variables and their relation to the regional spatial variation of aboveground biomass illustrated for North and East Kalimantan, Borneo.

PubMed

Van der Laan, Carina; Verweij, Pita A; Quiñones, Marcela J; Faaij, André Pc

2014-12-01

Land use and land cover change occurring in tropical forest landscapes contributes substantially to carbon emissions. Better insights into the spatial variation of aboveground biomass is therefore needed. By means of multiple statistical tests, including geographically weighted regression, we analysed the effects of eight variables on the regional spatial variation of aboveground biomass. North and East Kalimantan were selected as the case study region; the third largest carbon emitting Indonesian provinces. Strong positive relationships were found between aboveground biomass and the tested variables; altitude, slope, land allocation zoning, soil type, and distance to the nearest fire, road, river and city. Furthermore, the results suggest that the regional spatial variation of aboveground biomass can be largely attributed to altitude, distance to nearest fire and land allocation zoning. Our study showed that in this landscape, aboveground biomass could not be explained by one single variable; the variables were interrelated, with altitude as the dominant variable. Spatial analyses should therefore integrate a variety of biophysical and anthropogenic variables to provide a better understanding of spatial variation in aboveground biomass. Efforts to minimise carbon emissions should incorporate the identified factors, by 1) the maintenance of lands with high AGB or carbon stocks, namely in the identified zones at the higher altitudes; and 2) regeneration or sustainable utilisation of lands with low AGB or carbon stocks, dependent on the regeneration capacity of the vegetation. Low aboveground biomass densities can be found in the lowlands in burned areas, and in non-forest zones and production forests.
Airborne laser scanner-assisted estimation of aboveground biomass change in a temperate oak-pine forest

Treesearch

Nicholas S. Skowronski; Kenneth L. Clark; Michael Gallagher; Richard A. Birdsey; John L. Hom

2014-01-01

We estimated aboveground tree biomass and change in aboveground tree biomass using repeated airborne laser scanner (ALS) acquisitions and temporally coincident ground observations of forest biomass, for a relatively undisturbed period (2004-2007; ∇07-04), a contrasting period of disturbance (2007-2009; ∇09-07...
Eliciting maize defense pathways aboveground attracts belowground biocontrol agents.

PubMed

Filgueiras, Camila Cramer; Willett, Denis S; Pereira, Ramom Vasconcelos; Moino Junior, Alcides; Pareja, Martin; Duncan, Larry W

2016-11-04

Plant defense pathways mediate multitrophic interactions above and belowground. Understanding the effects of these pathways on pests and natural enemies above and belowground holds great potential for designing effective control strategies. Here we investigate the effects of aboveground stimulation of plant defense pathways on the interactions between corn, the aboveground herbivore adult Diabrotica speciosa, the belowground herbivore larval D. speciosa, and the subterranean ento-mopathogenic nematode natural enemy Heterorhabditis amazonensis. We show that adult D. speciosa recruit to aboveground herbivory and methyl salicylate treatment, that larval D. speciosa are relatively indiscriminate, and that H. amazonensis en-tomopathogenic nematodes recruit to corn fed upon by adult D. speciosa. These results suggest that entomopathogenicnematodes belowground can be highly attuned to changes in the aboveground parts of plants and that biological control can be enhanced with induced plant defense in this and similar systems.
Disentangling the effects of species diversity, and intraspecific and interspecific tree size variation on aboveground biomass in dry zone homegarden agroforestry systems.

PubMed

Ali, Arshad; Mattsson, Eskil

2017-11-15

The biodiversity - aboveground biomass relationship has been intensively studied in recent decades. However, no consensus has been arrived to consider the interplay of species diversity, and intraspecific and interspecific tree size variation in driving aboveground biomass, after accounting for the effects of plot size heterogeneity, soil fertility and stand quality in natural forest including agroforests. We tested the full, partial and no mediations effects of species diversity, and intraspecific and interspecific tree size variation on aboveground biomass by employing structural equation models (SEMs) using data from 45 homegarden agroforestry systems in Sri Lanka. The full mediation effect of either species diversity or intraspecific and interspecific tree size variation was rejected, while the partial and no mediation effects were accepted. In the no mediation SEM, homegarden size had the strongest negative direct effect (β=-0.49) on aboveground biomass (R 2 =0.65), followed by strong positive direct effect of intraspecific tree size variation (β=0.32), species diversity (β=0.29) and interspecific tree size variation (β=0.28). Soil fertility had a negative direct effect on interspecific tree size variation (β=-0.31). Stand quality had a significant positive total effect on aboveground biomass (β=0.28), but homegarden size had a significant negative total effect (β=-0.62), while soil fertility had a non-significant total effect on aboveground biomass. Similar to the no mediation SEM, the partial mediation SEMs had explained almost similar variation in aboveground biomass because species diversity, and intraspecific and interspecific tree size variation had non-significant indirect effects on aboveground biomass via each other. Our results strongly suggest that a multilayered tree canopy structure, due to high intraspecific and interspecific tree size variation, increases light capture and efficient utilization of resources among component species, and hence, support the niche complementarity mechanism via plant-plant interactions. Copyright © 2017 Elsevier B.V. All rights reserved.
Ecological linkages between aboveground and belowground biota.

PubMed

Wardle, David A; Bardgett, Richard D; Klironomos, John N; Setälä, Heikki; van der Putten, Wim H; Wall, Diana H

2004-06-11

All terrestrial ecosystems consist of aboveground and belowground components that interact to influence community- and ecosystem-level processes and properties. Here we show how these components are closely interlinked at the community level, reinforced by a greater degree of specificity between plants and soil organisms than has been previously supposed. As such, aboveground and belowground communities can be powerful mutual drivers, with both positive and negative feedbacks. A combined aboveground-belowground approach to community and ecosystem ecology is enhancing our understanding of the regulation and functional significance of biodiversity and of the environmental impacts of human-induced global change phenomena.
Assimilation of repeated woody biomass observations constrains decadal ecosystem carbon cycle uncertainty in aggrading forests

NASA Astrophysics Data System (ADS)

Smallman, T. L.; Exbrayat, J.-F.; Mencuccini, M.; Bloom, A. A.; Williams, M.

2017-03-01

Forest carbon sink strengths are governed by plant growth, mineralization of dead organic matter, and disturbance. Across landscapes, remote sensing can provide information about aboveground states of forests and this information can be linked to models to estimate carbon cycling in forests close to steady state. For aggrading forests this approach is more challenging and has not been demonstrated. Here we apply a Bayesian approach, linking a simple model to a range of data, to evaluate their information content, for two aggrading forests. We compare high information content analyses using local observations with retrievals using progressively sparser remotely sensed information (repeated, single, and no woody biomass observations). The net biome productivity of both forests is constrained to be a net sink with <2 Mg C ha-1 yr-1 variation across the range of inputs. However, the sequestration of particular carbon pool(s) varies with assimilated biomass information. Assimilation of repeated biomass observations reduces uncertainty and/or bias in all ecosystem C pools not just wood, compared to analyses using single or no stock information. As verification, our repeated biomass analysis explains 78-86% of variation in litter dynamics at one forest, while at the second forest total dead organic matter estimates are within observational uncertainty. The uncertainty of retrieved ecosystem traits in the repeated biomass analysis is reduced by up to 50% compared to analyses with less biomass information. This study quantifies the importance of repeated woody observations in constraining the dynamics of both wood and dead organic matter, highlighting the benefit of proposed remote sensing missions.
Aboveground insect herbivory increases plant competitive asymmetry, while belowground herbivory mitigates the effect

PubMed Central

Strengbom, Joachim; Viketoft, Maria; Bommarco, Riccardo

2016-01-01

Insect herbivores can shift the composition of a plant community, but the mechanism underlying such shifts remains largely unexplored. A possibility is that insects alter the competitive symmetry between plant species. The effect of herbivory on competition likely depends on whether the plants are subjected to aboveground or belowground herbivory or both, and also depends on soil nitrogen levels. It is unclear how these biotic and abiotic factors interactively affect competition. In a greenhouse experiment, we measured competition between two coexisting grass species that respond differently to nitrogen deposition: Dactylis glomerata L., which is competitively favoured by nitrogen addition, and Festuca rubra L., which is competitively favoured on nitrogen-poor soils. We predicted: (1) that aboveground herbivory would reduce competitive asymmetry at high soil nitrogen by reducing the competitive advantage of D. glomerata; and (2), that belowground herbivory would relax competition at low soil nitrogen, by reducing the competitive advantage of F. rubra. Aboveground herbivory caused a 46% decrease in the competitive ability of F. rubra, and a 23% increase in that of D. glomerata, thus increasing competitive asymmetry, independently of soil nitrogen level. Belowground herbivory did not affect competitive symmetry, but the combined influence of above- and belowground herbivory was weaker than predicted from their individual effects. Belowground herbivory thus mitigated the increased competitive asymmetry caused by aboveground herbivory. D. glomerata remained competitively dominant after the cessation of aboveground herbivory, showing that the influence of herbivory continued beyond the feeding period. We showed that insect herbivory can strongly influence plant competitive interactions. In our experimental plant community, aboveground insect herbivory increased the risk of competitive exclusion of F. rubra. Belowground herbivory appeared to mitigate the influence of aboveground herbivory, and this mechanism may play a role for plant species coexistence. PMID:27069805
Aboveground insect herbivory increases plant competitive asymmetry, while belowground herbivory mitigates the effect.

PubMed

Borgström, Pernilla; Strengbom, Joachim; Viketoft, Maria; Bommarco, Riccardo

2016-01-01

Insect herbivores can shift the composition of a plant community, but the mechanism underlying such shifts remains largely unexplored. A possibility is that insects alter the competitive symmetry between plant species. The effect of herbivory on competition likely depends on whether the plants are subjected to aboveground or belowground herbivory or both, and also depends on soil nitrogen levels. It is unclear how these biotic and abiotic factors interactively affect competition. In a greenhouse experiment, we measured competition between two coexisting grass species that respond differently to nitrogen deposition: Dactylis glomerata L., which is competitively favoured by nitrogen addition, and Festuca rubra L., which is competitively favoured on nitrogen-poor soils. We predicted: (1) that aboveground herbivory would reduce competitive asymmetry at high soil nitrogen by reducing the competitive advantage of D. glomerata; and (2), that belowground herbivory would relax competition at low soil nitrogen, by reducing the competitive advantage of F. rubra. Aboveground herbivory caused a 46% decrease in the competitive ability of F. rubra, and a 23% increase in that of D. glomerata, thus increasing competitive asymmetry, independently of soil nitrogen level. Belowground herbivory did not affect competitive symmetry, but the combined influence of above- and belowground herbivory was weaker than predicted from their individual effects. Belowground herbivory thus mitigated the increased competitive asymmetry caused by aboveground herbivory. D. glomerata remained competitively dominant after the cessation of aboveground herbivory, showing that the influence of herbivory continued beyond the feeding period. We showed that insect herbivory can strongly influence plant competitive interactions. In our experimental plant community, aboveground insect herbivory increased the risk of competitive exclusion of F. rubra. Belowground herbivory appeared to mitigate the influence of aboveground herbivory, and this mechanism may play a role for plant species coexistence.
Resolving model parameter values from carbon and nitrogen stock measurements in a wide range of tropical mature forests using nonlinear inversion and regression trees

USGS Publications Warehouse

Liu, S.; Anderson, P.; Zhou, G.; Kauffman, B.; Hughes, F.; Schimel, D.; Watson, Vicente; Tosi, Joseph

2008-01-01

Objectively assessing the performance of a model and deriving model parameter values from observations are critical and challenging in landscape to regional modeling. In this paper, we applied a nonlinear inversion technique to calibrate the ecosystem model CENTURY against carbon (C) and nitrogen (N) stock measurements collected from 39 mature tropical forest sites in seven life zones in Costa Rica. Net primary productivity from the Moderate-Resolution Imaging Spectroradiometer (MODIS), C and N stocks in aboveground live biomass, litter, coarse woody debris (CWD), and in soils were used to calibrate the model. To investigate the resolution of available observations on the number of adjustable parameters, inversion was performed using nine setups of adjustable parameters. Statistics including observation sensitivity, parameter correlation coefficient, parameter sensitivity, and parameter confidence limits were used to evaluate the information content of observations, resolution of model parameters, and overall model performance. Results indicated that soil organic carbon content, soil nitrogen content, and total aboveground biomass carbon had the highest information contents, while measurements of carbon in litter and nitrogen in CWD contributed little to the parameter estimation processes. The available information could resolve the values of 2-4 parameters. Adjusting just one parameter resulted in under-fitting and unacceptable model performance, while adjusting five parameters simultaneously led to over-fitting. Results further indicated that the MODIS NPP values were compressed as compared with the spatial variability of net primary production (NPP) values inferred from inverse modeling. Using inverse modeling to infer NPP and other sensitive model parameters from C and N stock observations provides an opportunity to utilize data collected by national to regional forest inventory systems to reduce the uncertainties in the carbon cycle and generate valuable databases to validate and improve MODIS NPP algorithms.
Would protecting tropical forest fragments provide carbon and biodiversity cobenefits under REDD+?

PubMed

Magnago, Luiz Fernando S; Magrach, Ainhoa; Laurance, William F; Martins, Sebastião V; Meira-Neto, João Augusto A; Simonelli, Marcelo; Edwards, David P

2015-09-01

Tropical forests store vast amounts of carbon and are the most biodiverse terrestrial habitats, yet they are being converted and degraded at alarming rates. Given global shortfalls in the budgets required to prevent carbon and biodiversity loss, we need to seek solutions that simultaneously address both issues. Of particular interest are carbon-based payments under the Reducing Emissions from Deforestation and Forest Degradation (REDD+) mechanism to also conserve biodiversity at no additional cost. One potential is for REDD+ to protect forest fragments, especially within biomes where contiguous forest cover has diminished dramatically, but we require empirical tests of the strength of any carbon and biodiversity cobenefits in such fragmented systems. Using the globally threatened Atlantic Forest landscape, we measured above-ground carbon stocks within forest fragments spanning 13 to 23 442 ha in area and with different degrees of isolation. We related these stocks to tree community structure and to the richness and abundance of endemic and IUCN Red-listed species. We found that increasing fragment size has a positive relationship with above-ground carbon stock and with abundance of IUCN Red-listed species and tree community structure. We also found negative relationships between distance from large forest block and tree community structure, endemic species richness and abundance, and IUCN Red-listed species abundance. These resulted in positive congruence between carbon stocks and Red-listed species, and the abundance and richness of endemic species, demonstrating vital cobenefits. As such, protecting forest fragments in hotspots of biodiversity, particularly larger fragments and those closest to sources, offers important carbon and biodiversity cobenefits. More generally, our results suggest that macroscale models of cobenefits under REDD+ have likely overlooked key benefits at small scales, indicating the necessity to apply models that include finer-grained assessments in fragmented landscapes rather than using averaged coarse-grained cells. © 2015 John Wiley & Sons Ltd.
Spatial Structure of Above-Ground Biomass Limits Accuracy of Carbon Mapping in Rainforest but Large Scale Forest Inventories Can Help to Overcome.

PubMed

Guitet, Stéphane; Hérault, Bruno; Molto, Quentin; Brunaux, Olivier; Couteron, Pierre

2015-01-01

Precise mapping of above-ground biomass (AGB) is a major challenge for the success of REDD+ processes in tropical rainforest. The usual mapping methods are based on two hypotheses: a large and long-ranged spatial autocorrelation and a strong environment influence at the regional scale. However, there are no studies of the spatial structure of AGB at the landscapes scale to support these assumptions. We studied spatial variation in AGB at various scales using two large forest inventories conducted in French Guiana. The dataset comprised 2507 plots (0.4 to 0.5 ha) of undisturbed rainforest distributed over the whole region. After checking the uncertainties of estimates obtained from these data, we used half of the dataset to develop explicit predictive models including spatial and environmental effects and tested the accuracy of the resulting maps according to their resolution using the rest of the data. Forest inventories provided accurate AGB estimates at the plot scale, for a mean of 325 Mg.ha-1. They revealed high local variability combined with a weak autocorrelation up to distances of no more than10 km. Environmental variables accounted for a minor part of spatial variation. Accuracy of the best model including spatial effects was 90 Mg.ha-1 at plot scale but coarse graining up to 2-km resolution allowed mapping AGB with accuracy lower than 50 Mg.ha-1. Whatever the resolution, no agreement was found with available pan-tropical reference maps at all resolutions. We concluded that the combined weak autocorrelation and weak environmental effect limit AGB maps accuracy in rainforest, and that a trade-off has to be found between spatial resolution and effective accuracy until adequate "wall-to-wall" remote sensing signals provide reliable AGB predictions. Waiting for this, using large forest inventories with low sampling rate (<0.5%) may be an efficient way to increase the global coverage of AGB maps with acceptable accuracy at kilometric resolution.
Soil warming and CO2 enrichment induce biomass shifts in alpine tree line vegetation.

PubMed

Dawes, Melissa A; Philipson, Christopher D; Fonti, Patrick; Bebi, Peter; Hättenschwiler, Stephan; Hagedorn, Frank; Rixen, Christian

2015-05-01

Responses of alpine tree line ecosystems to increasing atmospheric CO2 concentrations and global warming are poorly understood. We used an experiment at the Swiss tree line to investigate changes in vegetation biomass after 9 years of free air CO2 enrichment (+200 ppm; 2001-2009) and 6 years of soil warming (+4 °C; 2007-2012). The study contained two key tree line species, Larix decidua and Pinus uncinata, both approximately 40 years old, growing in heath vegetation dominated by dwarf shrubs. In 2012, we harvested and measured biomass of all trees (including root systems), above-ground understorey vegetation and fine roots. Overall, soil warming had clearer effects on plant biomass than CO2 enrichment, and there were no interactive effects between treatments. Total plant biomass increased in warmed plots containing Pinus but not in those with Larix. This response was driven by changes in tree mass (+50%), which contributed an average of 84% (5.7 kg m(-2) ) of total plant mass. Pinus coarse root mass was especially enhanced by warming (+100%), yielding an increased root mass fraction. Elevated CO2 led to an increased relative growth rate of Larix stem basal area but no change in the final biomass of either tree species. Total understorey above-ground mass was not altered by soil warming or elevated CO2 . However, Vaccinium myrtillus mass increased with both treatments, graminoid mass declined with warming, and forb and nonvascular plant (moss and lichen) mass decreased with both treatments. Fine roots showed a substantial reduction under soil warming (-40% for all roots <2 mm in diameter at 0-20 cm soil depth) but no change with CO2 enrichment. Our findings suggest that enhanced overall productivity and shifts in biomass allocation will occur at the tree line, particularly with global warming. However, individual species and functional groups will respond differently to these environmental changes, with consequences for ecosystem structure and functioning. © 2014 John Wiley & Sons Ltd.
Methods for estimating aboveground biomass and its components for Douglas-fir and lodgepole pine trees

Treesearch

K.P. Poudel; H. Temesgen

2016-01-01

Estimating aboveground biomass and its components requires sound statistical formulation and evaluation. Using data collected from 55 destructively sampled trees in different parts of Oregon, we evaluated the performance of three groups of methods to estimate total aboveground biomass and (or) its components based on the bias and root mean squared error (RMSE) that...
Extraction and textural characterization of above-ground areas from aerial stereo pairs: a quality assessment

NASA Astrophysics Data System (ADS)

Baillard, C.; Dissard, O.; Jamet, O.; Maître, H.

Above-ground analysis is a key point to the reconstruction of urban scenes, but it is a difficult task because of the diversity of the involved objects. We propose a new method to above-ground extraction from an aerial stereo pair, which does not require any assumption about object shape or nature. A Digital Surface Model is first produced by a stereoscopic matching stage preserving discontinuities, and then processed by a region-based Markovian classification algorithm. The produced above-ground areas are finally characterized as man-made or natural according to the grey level information. The quality of the results is assessed and discussed.
Effectiveness of residential wood-burning regulation on decreasing particulate matter levels and hospitalizations in the San Joaquin Valley Air Basin.

PubMed

Yap, Poh-Sin; Garcia, Cynthia

2015-04-01

We examined the impact of Rule 4901, aimed at reducing residential wood burning, on particulate matter levels and hospitalizations in the San Joaquin Valley Air Basin (SJVAB). Using general linear mixed models and generalized estimating equation models, we compared levels of particulate matter and of hospital admissions (age groups = 45-64 and ≥ 65 years) in the SJVAB for cardiovascular disease (CVD), ischemic heart disease (IHD), and chronic obstructive pulmonary disease during the burn seasons before (2000-2003) and after (2003-2006) implementation. After implementation, we observed reductions of 12%, 11%, and 15% in particulate matter 2.5 micrometers in diameter or smaller (PM2.5), and 8%, 7%, and 11% in coarse particles, in the entire SJVAB and in rural and urban regions of the air basin, respectively. Among those aged 65 years and older, Rule 4901 was estimated to prevent 7%, 8%, and 5% of CVD cases, and 16%, 17%, and 13% of IHD cases, in the entire SJVAB and in rural and urban regions, respectively. The study suggests that Rule 4901 is effective at reducing wintertime ambient PM2.5 levels and decreasing hospital admissions for heart disease among people aged 65 years and older.
Geochemical, Sulfur Isotopic Characteristics and Source Contributions of Size-Aggregated Aerosols Collected in Baring Head, New Zealand.

NASA Astrophysics Data System (ADS)

Li, J.; Michalski, G. M.; Davy, P.; Harvey, M.; Wilkins, B. P.; Katzman, T. L.

2017-12-01

Sulfate aerosols are critical to the climate, human health, and the hydrological cycle in the atmosphere, yet the sources of sulfate in aerosols are not completely understood. In this work, we evaluated the sources of sulfate in size-aggregated aerosols from the Southern Pacific Ocean and the land of New Zealand using geochemical and isotopic analyses. Aerosols were collected at Baring Head, New Zealand between 6/30/15 to 8/4/16 using two collectors, one only collects Southern Pacific Ocean derived aerosols (open-ocean collector), the other collects aerosols from both the ocean and the land (all-direction collector). Each collector is equipped with two filters to sample size-aggregated aerosols (fine aerosols: <0.5 um and coarse aerosols: 0.5-10 um). Our results show that fine and coarse aerosols show distinctive sulfate sources: sulfate in fine aerosols is a mixture of sea-salt sulfate ( 30%) and Non-Sea-Salt sulfate (NSS-SO42-, 70%), while coarse aerosols are dominated by sea-salt sulfate. However, some NSS-SO42- was also observed in coarse aerosols collected in summer, suggesting the presence of accumulation mode NSS-SO42- aerosols, which is possibly due to high summer biogenic DMS flux. The sources of sulfur in NSS-SO42- could be further determined by their d34S values. DMS emission is likely the sole sulfur source in the open-ocean collector as it shows constant DMS-like d34S signatures (15-18‰) throughout the year. Meanwhile, the d34S of NSS-SO42- in the all-direction collector display a seasonal trend: summer time d34S values are higher and DMS-like (15-18‰), indicating DMS emission is the dominant sulfur source; winter time d34S values are lower ( 6-12‰), therefore the sulfur is likely sourced from both DMS emission and terrestrial S input with low d34S values, such as volcanic activities, fossil fuel and wood burning.
Changes in aboveground primary production and carbon and nitrogen pools accompanying woody plant encroachment in a temperate savanna

Treesearch

R. Flint Hughes; Seeven R. Archer; Gegory P. Asner; Carol A. Wessman; Chad McMurtry; Jim Nelson; R. James. Ansley

2006-01-01

When woody plant abundance increases in grasslands and savannas, a phenomenon widely observed worldwide, there is considerable uncertainty as to whether aboveground net primary productivity (ANPP) and ecosystem carbon (C) and nitrogen (N) pools increase, decrease, or remain the same. We estimated ANPP and C and N pools in aboveground vegetation and surface soils on...

Long-term effects of fuel treatments on aboveground biomass accumulation in ponderosa pine forests of the northern Rocky Mountains

Treesearch

Kate A. Clyatt; Christopher R. Keyes; Sharon M. Hood

2017-01-01

Fuel treatments in ponderosa pine forests of the northern Rocky Mountains are commonly used to modify fire behavior, but it is unclear how different fuel treatments impact the subsequent production and distribution of aboveground biomass, especially in the long term. This research evaluated aboveground biomass responses 23 years after treatment in two silvicultural...
Plants as green phones: Novel insights into plant-mediated communication between below- and above-ground insects.

PubMed

Soler, Roxina; Harvey, Jeffrey A; Bezemer, T Martijn; Stuefer, Josef F

2008-08-01

Plants can act as vertical communication channels or 'green phones' linking soil-dwelling insects and insects in the aboveground ecosystem. When root-feeding insects attack a plant, the direct defense system of the shoot is activated, leading to an accumulation of phytotoxins in the leaves. The protection of the plant shoot elicited by root damage can impair the survival, growth and development of aboveground insect herbivores, thereby creating plant-based functional links between soil-dwelling insects and insects that develop in the aboveground ecosystem. The interactions between spatially separated insects below- and aboveground are not restricted to root and foliar plant-feeding insects, but can be extended to higher trophic levels such as insect parasitoids. Here we discuss some implications of plants acting as communication channels or 'green phones' between root and foliar-feeding insects and their parasitoids, focusing on recent findings that plants attacked by root-feeding insects are significantly less attractive for the parasitoids of foliar-feeding insects.
Above-ground biomass of mangrove species. I. Analysis of models

NASA Astrophysics Data System (ADS)

Soares, Mário Luiz Gomes; Schaeffer-Novelli, Yara

2005-10-01

This study analyzes the above-ground biomass of Rhizophora mangle and Laguncularia racemosa located in the mangroves of Bertioga (SP) and Guaratiba (RJ), Southeast Brazil. Its purpose is to determine the best regression model to estimate the total above-ground biomass and compartment (leaves, reproductive parts, twigs, branches, trunk and prop roots) biomass, indirectly. To do this, we used structural measurements such as height, diameter at breast-height (DBH), and crown area. A combination of regression types with several compositions of independent variables generated 2.272 models that were later tested. Subsequent analysis of the models indicated that the biomass of reproductive parts, branches, and prop roots yielded great variability, probably because of environmental factors and seasonality (in the case of reproductive parts). It also indicated the superiority of multiple regression to estimate above-ground biomass as it allows researchers to consider several aspects that affect above-ground biomass, specially the influence of environmental factors. This fact has been attested to the models that estimated the biomass of crown compartments.
Interactive Effects of Climate Change and Decomposer Communities on the Stabilization of Wood-Derived Carbon Pools: Catalyst for a New Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Resh, Sigrid C.

Globally, forest soils store ~two-thirds as much carbon (C) as the atmosphere. Although wood makes up the majority of forest biomass, the importance of wood contributions to soil C pools is unknown. Even with recent advances in the mechanistic understanding of soil processes, integrative studies tracing C input pathways and biological fluxes within and from soils are lacking. Therefore, our research objectives were to assess the impact of different fungal decay pathways (i.e., white-rot versus brown-rot)—in interaction with wood quality, soil temperature, wood location (i.e., soil surface and buried in mineral soil), and soil texture—on the transformation of woody materialmore » into soil CO 2 efflux, dissolved organic carbon (DOC), and soil C pools. The use of 13C-depleted woody biomass harvested from the Rhinelander, WI free-air carbon dioxide enrichment (Aspen-FACE) experiment affords the unique opportunity to distinguish the wood-derived C from other soil C fluxes and pools. We established 168 treatment plots across six field sites (three sand and three loam textured soil). Treatment plots consisted of full-factorial design with the following treatments: 1. Wood chips from elevated CO 2, elevated CO 2 + O 3, or ambient atmosphere AspenFACE treatments; 2. Inoculated with white rot (Bjerkandera adusta) or brown rot (Gloeophyllum sepiarium) pure fungal cultures, or the original suite of endemic microbial community on the logs; and 3. Buried (15cm in soil as a proxy for coarse roots) or surface applied wood chips. We also created a warming treatment using open-topped, passive warming chambers on a subset of the above treatments. Control plots with no added wood (“no chip control”) were incorporated into the research design. Soils were sampled for initial δ 13C values, CN concentrations, and bulk density. A subset of plots were instrumented with lysimeters for sampling soil water and temperature data loggers for measuring soil temperatures. To determine the early pathways of decomposition, we measured soil surface CO 2 efflux, dissolved organic C (DOC), and DO 13C approximately monthly over two growing seasons from a subsample of the research plots. To determine the portion of soil surface CO 2 efflux attributable to wood-derived C, we used Keeling plot techniques to estimate the associated δ 13C values of the soil CO 2 efflux. We measured the δ 13CO 2 once during the peak of each growing season. Initial values for soil δ 13C values and CN concentrations averaged across the six sites were -26.8‰ (standard error = 0.04), 2.46% (se = 0.11), and 0.15% (se = 0.01), respectively. The labeled wood chips from the Aspen FACE treatments had an average δ13C value of -39.5‰ (se 0.10). The >12 ‰ isotopic difference between the soil and wood chip δ 13C values provides the basis for tracking the wood-derived C through the early stages of decomposition and subsequent storage in the soil. Across our six research sites, average soil surface CO 2 efflux ranged from 1.04 to 2.00 g CO 2 m -2 h -1 for the first two growing seasons. No wood chip controls had an average soil surface CO 2 efflux of 0.67 g CO 2 m -2 h -1 or about half of that of the wood chip treatment plots. Wood-derived CO 2 efflux was higher for loam textured soils relative to sands (0.70 and 0.54 g CO 2 m -2 h -1, respectively; p = 0.045)), for surface relative to buried wood chip treatments (0.92 and 0.39 g CO 2 m -2 h -1, respectively; p < 0.001), for warmed relative to ambient temperature treatments (0.99 and 0.78 g CO 2 m -2 h -1, respectively; 0.004), and for natural rot relative to brown and white rots (0.93, 0.82, and 0.78 g CO 2 m -2 h -1, respectively; p = 0.068). Our first two growing seasons of soil surface CO 2 efflux data show that wood chip location (i.e., surface vs. buried chip application) is very important, with surface chips loosing twice the wood-derived CO 2. The DOC data support this trend for greater loss of ecosystem C from surface chips. This has strong implications for the importance of root and buried wood for ecosystem C retention. This strong chip location effect on wood-derived C loss was significantly modified by soil texture, soil temperature, decomposer communities, and wood quality as effected by potential future CO 2 and O 3 levels.« less
Sea-Floor Character and Sedimentary Processes in the Vicinity of Woods Hole, Massachusetts

USGS Publications Warehouse

Poppe, Lawrence J.; McMullen, Katherine Y.; Foster, David S.; Blackwood, Dann S.; Williams, S. Jeffress; Ackerman, Seth D.; Barnum, Steven R.; Brennan, Rick T.

2008-01-01

Continuous-coverage multibeam bathymetric models and sidescan-sonar imagery have been verified with high-resolution seismic-reflection profiles, sediment sampling, and bottom photography. Together these data layers provide detailed base maps that yield topographic, compositional, and environmental perspectives of the sea floor in the vicinity of Woods Hole, an important harbor and major passage between the Elizabeth Islands and Cape Cod, Massachusetts. Tidally dominated high-energy environments within Woods Hole have prevented deposition of Holocene marine sediments, exposed underlying glacial drift of the Buzzards Bay moraine, and winnowed finer grained sediments, leaving lag deposits of boulders and gravel. These conditions have also enlarged and preserved depressions in the moraine surface that were originally kettle holes and formed ebb-tidal deltas at the entrances to passages. Fields of transverse and barchanoid sand waves dominate across the southern part of the study area in Vineyard Sound, where benthic environments are characterized by processes associated with coarse-bedload transport. Transverse sand waves dominate near shoals where sediment supply is greater and have asymmetries that indicate that the shoals are shaped and maintained by clockwise gyres of net sediment transport. Barchanoid sand waves, which are most common where Holocene sediments are thinner, commonly align into elongate fields that have smaller isolated waves concentrated at the eastern ends and that progressively widen and have waveforms that increase in amplitude, wavelength, and complexity westward. The northern, protected parts of the Little and Inner Harbors are characterized by muddy sediment and processes associated with deposition. A pockmark field in Little Harbor and the muddy, organic-rich sediments that form a scarp along the edge of Parker Flat are evidence for the presence of submerged marsh deposits formed during the Holocene rise in sea level.
Terrestrial habitat selection and strong density-dependent mortality in recently metamorphosed amphibians.

PubMed

Patrick, David A; Harper, Elizabeth B; Hunter, Malcolm L; Calhoun, Aram J K

2008-09-01

To predict the effects of terrestrial habitat change on amphibian populations, we need to know how amphibians respond to habitat heterogeneity, and whether habitat choice remains consistent throughout the life-history cycle. We conducted four experiments to evaluate how the spatial distribution of juvenile wood frogs, Rana sylvatica (including both overall abundance and localized density), was influenced by habitat choice and habitat structure, and how this relationship changed with spatial scale and behavioral phase. The four experiments included (1) habitat manipulation on replicated 10-ha landscapes surrounding breeding pools; (2) short-term experiments with individual frogs emigrating through a manipulated landscape of 1 m wide hexagonal patches; and habitat manipulations in (3) small (4-m2); and (4) large (100-m2) enclosures with multiple individuals to compare behavior both during and following emigration. The spatial distribution of juvenile wood frogs following emigration resulted from differences in the scale at which juvenile amphibians responded to habitat heterogeneity during active vs. settled behavioral phases. During emigration, juvenile wood frogs responded to coarse-scale variation in habitat (selection between 2.2-ha forest treatments) but not to fine-scale variation. After settling, however, animals showed habitat selection at much smaller scales (2-4 m2). This resulted in high densities of animals in small patches of suitable habitat where they experienced rapid mortality. No evidence of density-dependent habitat selection was seen, with juveniles typically choosing to remain at extremely high densities in high-quality habitat, rather than occupying low-quality habitat. These experiments demonstrate how prediction of the terrestrial distribution of juvenile amphibians requires understanding of the complex behavioral responses to habitat heterogeneity. Understanding these patterns is important, given that human alterations to amphibian habitats may generate extremely high densities of animals, resulting in high density-dependent mortality.
Estimating and mapping forest biomass using regression models and Spot-6 images (case study: Hyrcanian forests of north of Iran).

PubMed

Motlagh, Mohadeseh Ghanbari; Kafaky, Sasan Babaie; Mataji, Asadollah; Akhavan, Reza

2018-05-21

Hyrcanian forests of North of Iran are of great importance in terms of various economic and environmental aspects. In this study, Spot-6 satellite images and regression models were applied to estimate above-ground biomass in these forests. This research was carried out in six compartments in three climatic (semi-arid to humid) types and two altitude classes. In the first step, ground sampling methods at the compartment level were used to estimate aboveground biomass (Mg/ha). Then, by reviewing the results of other studies, the most appropriate vegetation indices were selected. In this study, three indices of NDVI, RVI, and TVI were calculated. We investigated the relationship between the vegetation indices and aboveground biomass measured at sample-plot level. Based on the results, the relationship between aboveground biomass values and vegetation indices was a linear regression with the highest level of significance for NDVI in all compartments. Since at the compartment level the correlation coefficient between NDVI and aboveground biomass was the highest, NDVI was used for mapping aboveground biomass. According to the results of this study, biomass values were highly different in various climatic and altitudinal classes with the highest biomass value observed in humid climate and high-altitude class.
Into the black and back: the ecology of brain investment in Neotropical army ants (Formicidae: Dorylinae)

NASA Astrophysics Data System (ADS)

Bulova, S.; Purce, K.; Khodak, P.; Sulger, E.; O'Donnell, S.

2016-04-01

Shifts to new ecological settings can drive evolutionary changes in animal sensory systems and in the brain structures that process sensory information. We took advantage of the diverse habitat ecology of Neotropical army ants to test whether evolutionary transitions from below- to above-ground activity were associated with changes in brain structure. Our estimates of genus-typical frequencies of above-ground activity suggested a high degree of evolutionary plasticity in habitat use among Neotropical army ants. Brain structure consistently corresponded to degree of above-ground activity among genera and among species within genera. The most above-ground genera (and species) invested relatively more in visual processing brain tissues; the most subterranean species invested relatively less in central processing higher-brain centers (mushroom body calyces). These patterns suggest a strong role of sensory ecology (e.g., light levels) in selecting for army ant brain investment evolution and further suggest that the subterranean environment poses reduced cognitive challenges to workers. The highly above-ground active genus Eciton was exceptional in having relatively large brains and particularly large and structurally complex optic lobes. These patterns suggest that the transition to above-ground activity from ancestors that were largely subterranean for approximately 60 million years was followed by re-emergence of enhanced visual function in workers.
Aboveground vs. Belowground Carbon Stocks in African Tropical Lowland Rainforest: Drivers and Implications.

PubMed

Doetterl, Sebastian; Kearsley, Elizabeth; Bauters, Marijn; Hufkens, Koen; Lisingo, Janvier; Baert, Geert; Verbeeck, Hans; Boeckx, Pascal

2015-01-01

African tropical rainforests are one of the most important hotspots to look for changes in the upcoming decades when it comes to C storage and release. The focus of studying C dynamics in these systems lies traditionally on living aboveground biomass. Belowground soil organic carbon stocks have received little attention and estimates of the size, controls and distribution of soil organic carbon stocks are highly uncertain. In our study on lowland rainforest in the central Congo basin, we combine both an assessment of the aboveground C stock with an assessment of the belowground C stock and analyze the latter in terms of functional pools and controlling factors. Our study shows that despite similar vegetation, soil and climatic conditions, soil organic carbon stocks in an area with greater tree height (= larger aboveground carbon stock) were only half compared to an area with lower tree height (= smaller aboveground carbon stock). This suggests that substantial variability in the aboveground vs. belowground C allocation strategy and/or C turnover in two similar tropical forest systems can lead to significant differences in total soil organic C content and C fractions with important consequences for the assessment of the total C stock of the system. We suggest nutrient limitation, especially potassium, as the driver for aboveground versus belowground C allocation. However, other drivers such as C turnover, tree functional traits or demographic considerations cannot be excluded. We argue that large and unaccounted variability in C stocks is to be expected in African tropical rain-forests. Currently, these differences in aboveground and belowground C stocks are not adequately verified and implemented mechanistically into Earth System Models. This will, hence, introduce additional uncertainty to models and predictions of the response of C storage of the Congo basin forest to climate change and its contribution to the terrestrial C budget.
Aboveground vs. Belowground Carbon Stocks in African Tropical Lowland Rainforest: Drivers and Implications

PubMed Central

Bauters, Marijn; Hufkens, Koen; Lisingo, Janvier; Baert, Geert; Verbeeck, Hans; Boeckx, Pascal

2015-01-01

Background African tropical rainforests are one of the most important hotspots to look for changes in the upcoming decades when it comes to C storage and release. The focus of studying C dynamics in these systems lies traditionally on living aboveground biomass. Belowground soil organic carbon stocks have received little attention and estimates of the size, controls and distribution of soil organic carbon stocks are highly uncertain. In our study on lowland rainforest in the central Congo basin, we combine both an assessment of the aboveground C stock with an assessment of the belowground C stock and analyze the latter in terms of functional pools and controlling factors. Principal Findings Our study shows that despite similar vegetation, soil and climatic conditions, soil organic carbon stocks in an area with greater tree height (= larger aboveground carbon stock) were only half compared to an area with lower tree height (= smaller aboveground carbon stock). This suggests that substantial variability in the aboveground vs. belowground C allocation strategy and/or C turnover in two similar tropical forest systems can lead to significant differences in total soil organic C content and C fractions with important consequences for the assessment of the total C stock of the system. Conclusions/Significance We suggest nutrient limitation, especially potassium, as the driver for aboveground versus belowground C allocation. However, other drivers such as C turnover, tree functional traits or demographic considerations cannot be excluded. We argue that large and unaccounted variability in C stocks is to be expected in African tropical rain-forests. Currently, these differences in aboveground and belowground C stocks are not adequately verified and implemented mechanistically into Earth System Models. This will, hence, introduce additional uncertainty to models and predictions of the response of C storage of the Congo basin forest to climate change and its contribution to the terrestrial C budget. PMID:26599231
Effects of dietary coarsely ground corn and 3 bedding floor types on broiler live performance, litter characteristics, gizzard and proventriculus weight, and nutrient digestibility.

PubMed

Xu, Y; Lin, Y M; Stark, C R; Ferket, P R; Williams, C M; Brake, J

2017-07-01

The effects of zero or 50% dietary coarsely ground corn (CC) in pelleted and screened grower and finisher diets on broilers reared on 3 bedding floor types (plastic net [NET], new pine wood shavings litter [NEW], or old pine wood shavings litter [OLD]) on broiler live performance, litter characteristics, gizzard and proventriculus weight, and apparent ileal digestibility (AID) were studied in a 2 × 3 factorial arrangement of treatments. Fine corn was produced with a hammermill (271 μm) and CC with a roller mill (1145 μm). Utilization of CC reduced milling cost by 9.47 cents per MT with similar nutrient content of screened pellets. The 50% CC treatment exhibited improved (P ≤ 0.05) feed intake at 42 d (2.5%) and 49 d (3.0%), and BW (5.4%) and FCR from 28 d (1.4%). Birds on NEW litter exhibited improved (P < 0.05) BW at 28 and 35 d and 42 d FCR as compared to NET and 49 d FCR compared to NET and OLD. The 50% CC treatment exhibited increased (P < 0.05) gizzard weight but decreased proventriculus weight at 49 d. NEW litter birds exhibited increased (P ≤ 0.05) gizzard weight at 28 d and 49 d and decreased proventriculus weight as compared to NET at 49 days. The 50% CC treatment exhibited decreased (P ≤ 0.05) litter moisture at 35 and 42 d, litter N at 35 and 49 d, and litter pH at 49 days. OLD litter birds exhibited greater (P < 0.05) litter N at 14, 35, and 49 d, as well as litter moisture, pH, and ammonia concentration at 49 days. The 50% CC group also exhibited improved AID of nitrogen (P < 0.05). Broilers fed pelleted and screened diets containing 50% CC exhibited improved live performance and reduced litter moisture while use of NEW litter resulted in a somewhat similar effect, which indicated that consumption of NEW litter also facilitated gastric development and function. © 2017 Poultry Science Association Inc.
Development of Spatiotemporal Bias-Correction Techniques for Downscaling GCM Predictions

NASA Astrophysics Data System (ADS)

Hwang, S.; Graham, W. D.; Geurink, J.; Adams, A.; Martinez, C. J.

2010-12-01

Accurately representing the spatial variability of precipitation is an important factor for predicting watershed response to climatic forcing, particularly in small, low-relief watersheds affected by convective storm systems. Although Global Circulation Models (GCMs) generally preserve spatial relationships between large-scale and local-scale mean precipitation trends, most GCM downscaling techniques focus on preserving only observed temporal variability on point by point basis, not spatial patterns of events. Downscaled GCM results (e.g., CMIP3 ensembles) have been widely used to predict hydrologic implications of climate variability and climate change in large snow-dominated river basins in the western United States (Diffenbaugh et al., 2008; Adam et al., 2009). However fewer applications to smaller rain-driven river basins in the southeastern US (where preserving spatial variability of rainfall patterns may be more important) have been reported. In this study a new method was developed to bias-correct GCMs to preserve both the long term temporal mean and variance of the precipitation data, and the spatial structure of daily precipitation fields. Forty-year retrospective simulations (1960-1999) from 16 GCMs were collected (IPCC, 2007; WCRP CMIP3 multi-model database: https://esg.llnl.gov:8443/), and the daily precipitation data at coarse resolution (i.e., 280km) were interpolated to 12km spatial resolution and bias corrected using gridded observations over the state of Florida (Maurer et al., 2002; Wood et al, 2002; Wood et al, 2004). In this method spatial random fields which preserved the observed spatial correlation structure of the historic gridded observations and the spatial mean corresponding to the coarse scale GCM daily rainfall were generated. The spatiotemporal variability of the spatio-temporally bias-corrected GCMs were evaluated against gridded observations, and compared to the original temporally bias-corrected and downscaled CMIP3 data for the central Florida. The hydrologic response of two southwest Florida watersheds to the gridded observation data, the original bias corrected CMIP3 data, and the new spatiotemporally corrected CMIP3 predictions was compared using an integrated surface-subsurface hydrologic model developed by Tampa Bay Water.
The response of ecosystem carbon pools to management approaches in loblolly pine (Pinus taeda L.) plantations

NASA Astrophysics Data System (ADS)

Vogel, J. G.; Bacon, A. R.; Bracho, R. G.; Gonzalez-Benecke, C. A.; Fox, T. D.; Laviner, M. A.; Kane, M.; Burkhart, H.; Martin, T.; Will, R.; Ross, C. W.; Grunwald, S.; Jokela, E. J.; Meek, C.

2016-12-01

Extending from Virginia to east Texas in the southeastern United States, managed pine plantations are an important component of the region's carbon cycle. An objective of the Pine Integrated Network: Education, Mitigation, and Adaptation project (PINEMAP) is to improve estimates of how ecosystem carbon pools respond to the management strategies used to increase the growth of loblolly pine plantations. Experimental studies (108 total) that have been used to understand plantation productivity and stand dynamics by university-forest industry cooperatives were measured for the carbon stored in the trees, roots, coarse-wood, detritus in soil, forest floor, understory and soils to 1-meter. The age of the studied plantations ranged from 4-26 years at the time of sampling, with 26 years very near the period when these plantations are commonly harvested. Across all study sites, 455 experimental plots were measured. The average C storage across all pools, sites, and treatments was 192 Mg C ha-1, with the average percentage of the total coming from soil (44%), tree biomass (40%), forest floor (8%), root (5%), soil detritus (2%), understory biomass (1%), and coarse-wood (<1%) pools. Plots had as a treatment either fertilization, competition control, and stand density control (thinning), and every possible combination of treatments including `no treatment'. A paired plot analysis was used where two plots at a site were examined for relative differences caused by a single treatment and these differences averaged across the region. Thinning as a stand-alone treatment significantly reduced forest floor mass by 60%, and the forest floor in the thinned plus either competition control or fertilization was 18.9% and 19.2% less, respectively, than unthinned stands combined with the same treatments. Competition control increased C storage in tree biomass by 12% and thinning decreased tree biomass by 32%. Thinning combined with fertilization had lower soil carbon (0-1 m) than unthinned-fertilized plots (22%), although the replication for this combination was relatively low (n=6). Overall these results suggest that maintaining higher tree densities increases ecosystem carbon storage across multiple pools of C in loblolly pine plantations.
Altered soil microbial community at elevated CO2 leads to loss of soil carbon

PubMed Central

Carney, Karen M.; Hungate, Bruce A.; Drake, Bert G.; Megonigal, J. Patrick

2007-01-01

Increased carbon storage in ecosystems due to elevated CO2 may help stabilize atmospheric CO2 concentrations and slow global warming. Many field studies have found that elevated CO2 leads to higher carbon assimilation by plants, and others suggest that this can lead to higher carbon storage in soils, the largest and most stable terrestrial carbon pool. Here we show that 6 years of experimental CO2 doubling reduced soil carbon in a scrub-oak ecosystem despite higher plant growth, offsetting ≈52% of the additional carbon that had accumulated at elevated CO2 in aboveground and coarse root biomass. The decline in soil carbon was driven by changes in soil microbial composition and activity. Soils exposed to elevated CO2 had higher relative abundances of fungi and higher activities of a soil carbon-degrading enzyme, which led to more rapid rates of soil organic matter degradation than soils exposed to ambient CO2. The isotopic composition of microbial fatty acids confirmed that elevated CO2 increased microbial utilization of soil organic matter. These results show how elevated CO2, by altering soil microbial communities, can cause a potential carbon sink to become a carbon source. PMID:17360374
Land use change and carbon stock dynamics in Sub-Saharan Africa - Case study of Western Africa - Ghana

NASA Astrophysics Data System (ADS)

Grieco, E.; Chiti, T.; Valentini, R.

2012-04-01

Among different regions of the world, Africa and particularly sub-Saharan Africa (SSA) has contributed less than any other to the greenhouse gas emissions, but it is also the region most vulnerable and the least well equipped to the consequences. In SSA the role of land use change in controlling CO2 emissions may be more critical than in any other regions and perhaps the most uncertain component of the global carbon cycle. The most typical example of incomplete estimates will arise from the lack of reliable data for carbon pools. Three factors account for much of the rest of the uncertainty: (1) initial stocks of carbon in ecosystems affected by land-use change, (2) per hectare changes in carbon stocks in response to different types of land-use change, and (3) legacy effects; that is, the time it takes for carbon stocks to equilibrate following a change in land use. Considering the source of uncertainty and the lack of field data for SSA, the study has been located in Ghana (Jomoro district, Western Region) where forest is the only source of wood for domestic uses and deforestation annual rate was 2.2% for the period 2005-2010. This study analyze the above mentioned gaps by assessing: 1) initial carbon stocks (tropical rain forest), 2) per hectare changes in carbon stocks as consequence of deforestation followed by six different main land uses [tree plantations (rubber, coconut, cocoa, oil palm, mixed plantations) and a secondary forest], 3) dynamics of soil carbon stocks through the time considering chronosequences. When accounting changes in carbon stocks in the UNFCCC framework, it is required to consider 5 carbon pools that are: aboveground biomass, belowground biomass, litter, dead wood and soil. Within REDD+ mechanism it is clear that only aboveground pool has to be always considered, belowground biomass is recommended and the others are facultative. Evidence from official UNFCCC reports suggests that only a very small fraction of developing countries currently reports data on soil carbon, although emissions from soils following deforestation are likely to be significant in many cases. Despite the common understanding about the effects of deforestation on different compartments in terms of carbon stocks (e.g. disappearance of biomass ) variations in soil carbon are much less perceptible, even after a radical change in land use . This study brings in the spotlight the soil reaction to radical land use change in the long run demonstrating that it is not so trifle as commonly believed. Importance of considering soil carbon stock for accounting land use change dynamics is not properly recognized in the international deforestation policies and its influence in mitigating climate change is nowadays neglected but it is really not negligible.
The positive relationships between plant coverage, species richness, and aboveground biomass are ubiquitous across plant growth forms in semi-steppe rangelands.

PubMed

Sanaei, Anvar; Ali, Arshad; Chahouki, Mohammad Ali Zare

2018-01-01

The positive relationships between biodiversity and aboveground biomass are important for biodiversity conservation and greater ecosystem functioning and services that humans depend on. However, the interaction effects of plant coverage and biodiversity on aboveground biomass across plant growth forms (shrubs, forbs and grasses) in natural rangelands are poorly studied. Here, we hypothesized that, while accounting for environmental factors and disturbance intensities, the positive relationships between plant coverage, biodiversity, and aboveground biomass are ubiquitous across plant growth forms in natural rangelands. We applied structural equation models (SEMs) using data from 735 quadrats across 35 study sites in semi-steppe rangelands in Iran. The combination of plant coverage and species richness rather than Shannon's diversity or species diversity (a latent variable of species richness and evenness) substantially enhance aboveground biomass across plant growth forms. In all selected SEMs, plant coverage had a strong positive direct effect on aboveground biomass (β = 0.72 for shrubs, 0.84 for forbs and 0.80 for grasses), followed by a positive effect of species richness (β = 0.26 for shrubs, 0.05 for forbs and 0.09 for grasses), and topographic factors. Disturbance intensity had a negative effect on plant coverage, whereas it had a variable effect on species richness across plant growth forms. Plant coverage had a strong positive total effect on aboveground biomass (β = 0.84 for shrubs, 0.88 for forbs, and 0.85 for grasses), followed by a positive effect of species richness, and a negative effect of disturbance intensity across plant growth forms. Our results shed light on the management of rangelands that is high plant coverage can significantly improve species richness and aboveground biomass across plant growth forms. We also found that high disturbance intensity due to heavy grazing has a strong negative effect on plant coverage rather than species richness in semi-steppe rangelands. This study suggests that proper grazing systems (e.g. rotational system) based on carrying capacity and stocking rate of a rangeland may be helpful for biodiversity conservation, better grazing of livestock, improvement of plant coverage and enhancement of aboveground biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.
Structural Health Monitoring of Above-Ground Storage Tank Floors by Ultrasonic Guided Wave Excitation on the Tank Wall.

PubMed

Lowe, Premesh S; Duan, Wenbo; Kanfoud, Jamil; Gan, Tat-Hean

2017-11-04

There is an increasing interest in using ultrasonic guided waves to assess the structural degradation of above-ground storage tank floors. This is a non-invasive and economically viable means of assessing structural degradation. Above-ground storage tank floors are ageing assets which need to be inspected periodically to avoid structural failure. At present, normal-stress type transducers are bonded to the tank annular chime to generate a force field in the thickness direction of the floor and excite fundamental symmetric and asymmetric Lamb modes. However, the majority of above-ground storage tanks in use have no annular chime due to a simplified design and/or have a degraded chime due to corrosion. This means that transducers cannot be mounted on the chime to assess structural health according to the present technology, and the market share of structural health monitoring of above-ground storage tank floors using ultrasonic guided wave is thus limited. Therefore, the present study investigates the potential of using the tank wall to bond the transducer instead of the tank annular chime. Both normal and shear type transducers were investigated numerically, and results were validated using a 4.1 m diameter above-ground storage tank. The study results show shear mode type transducers bonded to the tank wall can be used to assess the structural health of the above-ground tank floors using an ultrasonic guided wave. It is also shown that for the cases studied there is a 7.4 dB signal-to-noise ratio improvement at 45 kHz for the guided wave excitation on the tank wall using shear mode transducers.
Structural Health Monitoring of Above-Ground Storage Tank Floors by Ultrasonic Guided Wave Excitation on the Tank Wall

PubMed Central

Kanfoud, Jamil; Gan, Tat-Hean

2017-01-01

There is an increasing interest in using ultrasonic guided waves to assess the structural degradation of above-ground storage tank floors. This is a non-invasive and economically viable means of assessing structural degradation. Above-ground storage tank floors are ageing assets which need to be inspected periodically to avoid structural failure. At present, normal-stress type transducers are bonded to the tank annular chime to generate a force field in the thickness direction of the floor and excite fundamental symmetric and asymmetric Lamb modes. However, the majority of above-ground storage tanks in use have no annular chime due to a simplified design and/or have a degraded chime due to corrosion. This means that transducers cannot be mounted on the chime to assess structural health according to the present technology, and the market share of structural health monitoring of above-ground storage tank floors using ultrasonic guided wave is thus limited. Therefore, the present study investigates the potential of using the tank wall to bond the transducer instead of the tank annular chime. Both normal and shear type transducers were investigated numerically, and results were validated using a 4.1 m diameter above-ground storage tank. The study results show shear mode type transducers bonded to the tank wall can be used to assess the structural health of the above-ground tank floors using an ultrasonic guided wave. It is also shown that for the cases studied there is a 7.4 dB signal-to-noise ratio improvement at 45 kHz for the guided wave excitation on the tank wall using shear mode transducers. PMID:29113058
Below-ground herbivory limits induction of extrafloral nectar by above-ground herbivores

PubMed Central

Huang, Wei; Siemann, Evan; Carrillo, Juli; Ding, Jianqing

2015-01-01

Background and Aims Many plants produce extrafloral nectar (EFN), and increase production following above-ground herbivory, presumably to attract natural enemies of the herbivores. Below-ground herbivores, alone or in combination with those above ground, may also alter EFN production depending on the specificity of this defence response and the interactions among herbivores mediated through plant defences. To date, however, a lack of manipulative experiments investigating EFN production induced by above- and below-ground herbivory has limited our understanding of how below-ground herbivory mediates indirect plant defences to affect above-ground herbivores and their natural enemies. Methods In a greenhouse experiment, seedlings of tallow tree (Triadica sebifera) were subjected to herbivory by a specialist flea beetle (Bikasha collaris) that naturally co-occurs as foliage-feeding adults and root-feeding larvae. Seedlings were subjected to above-ground adults and/or below-ground larvae herbivory, and EFN production was monitored. Key Results Above- and/or below-ground herbivory significantly increased the percentage of leaves with active nectaries, the volume of EFN and the mass of soluble solids within the nectar. Simultaneous above- and below-ground herbivory induced a higher volume of EFN and mass of soluble solids than below-ground herbivory alone, but highest EFN production was induced by above-ground herbivory when below-ground herbivores were absent. Conclusions The induction of EFN production by below-ground damage suggests that systemic induction underlies some of the EFN response. The strong induction by above-ground herbivory in the absence of below-ground herbivory points to specific induction based on above- and below-ground signals that may be adaptive for this above-ground indirect defence. PMID:25681822
Below-ground herbivory limits induction of extrafloral nectar by above-ground herbivores.

PubMed

Huang, Wei; Siemann, Evan; Carrillo, Juli; Ding, Jianqing

2015-04-01

Many plants produce extrafloral nectar (EFN), and increase production following above-ground herbivory, presumably to attract natural enemies of the herbivores. Below-ground herbivores, alone or in combination with those above ground, may also alter EFN production depending on the specificity of this defence response and the interactions among herbivores mediated through plant defences. To date, however, a lack of manipulative experiments investigating EFN production induced by above- and below-ground herbivory has limited our understanding of how below-ground herbivory mediates indirect plant defences to affect above-ground herbivores and their natural enemies. In a greenhouse experiment, seedlings of tallow tree (Triadica sebifera) were subjected to herbivory by a specialist flea beetle (Bikasha collaris) that naturally co-occurs as foliage-feeding adults and root-feeding larvae. Seedlings were subjected to above-ground adults and/or below-ground larvae herbivory, and EFN production was monitored. Above- and/or below-ground herbivory significantly increased the percentage of leaves with active nectaries, the volume of EFN and the mass of soluble solids within the nectar. Simultaneous above- and below-ground herbivory induced a higher volume of EFN and mass of soluble solids than below-ground herbivory alone, but highest EFN production was induced by above-ground herbivory when below-ground herbivores were absent. The induction of EFN production by below-ground damage suggests that systemic induction underlies some of the EFN response. The strong induction by above-ground herbivory in the absence of below-ground herbivory points to specific induction based on above- and below-ground signals that may be adaptive for this above-ground indirect defence. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Interrelated effects of mycorrhiza and free-living nitrogen fixers cascade up to aboveground herbivores.

PubMed

Khaitov, Botir; Patiño-Ruiz, José David; Pina, Tatiana; Schausberger, Peter

2015-09-01

Aboveground plant performance is strongly influenced by belowground microorganisms, some of which are pathogenic and have negative effects, while others, such as nitrogen-fixing bacteria and arbuscular mycorrhizal fungi, usually have positive effects. Recent research revealed that belowground interactions between plants and functionally distinct groups of microorganisms cascade up to aboveground plant associates such as herbivores and their natural enemies. However, while functionally distinct belowground microorganisms commonly co-occur in the rhizosphere, their combined effects, and relative contributions, respectively, on performance of aboveground plant-associated organisms are virtually unexplored. Here, we scrutinized and disentangled the effects of free-living nitrogen-fixing (diazotrophic) bacteria Azotobacter chroococcum (DB) and arbuscular mycorrhizal fungi Glomus mosseae (AMF) on host plant choice and reproduction of the herbivorous two-spotted spider mite Tetranychus urticae on common bean plants Phaseolus vulgaris. Additionally, we assessed plant growth, and AMF and DB occurrence and density as affected by each other. Both AMF alone and DB alone increased spider mite reproduction to similar levels, as compared to the control, and exerted additive effects under co-occurrence. These effects were similarly apparent in host plant choice, that is, the mites preferred leaves from plants with both AMF and DB to plants with AMF or DB to plants grown without AMF and DB. DB, which also act as AMF helper bacteria, enhanced root colonization by AMF, whereas AMF did not affect DB abundance. AMF but not DB increased growth of reproductive plant tissue and seed production, respectively. Both AMF and DB increased the biomass of vegetative aboveground plant tissue. Our study breaks new ground in multitrophic belowground-aboveground research by providing first insights into the fitness implications of plant-mediated interactions between interrelated belowground fungi-bacteria and aboveground herbivores.
Nitrate losses, nutrients and heavy metal accumulation from substrates assembled for urban soils reconstruction.

PubMed

Civeira, G; Lavado, R S

2008-09-01

Urban soils may suffer mild to severe degradation as a result of physical and chemical alterations. To reconstruct these soils, a new upper horizon must be created, usually through the application of organic matter, one source of which is biosolids. Different soil mixtures were evaluated with regard to loss of nitrates in percolates and the uptake and incorporation of nutrients and heavy metals into plant tissues. The experiment was conducted in trays; treatments were mixtures of biosolids and a coarse material (e.g., sand or pine wood sawdust), combined in different proportions. Randomized trays were seeded with a mix of tall fescue (Festuca arundinacea L.) and perennial ryegrass (Lolium perenne L.). Plant biomass was quantified. Nitrates in percolates were measured, as were nutrients and heavy metals in mixtures and plant tissues. Plants accumulated substantially more N, and biomass was 40% higher, in the treatments with higher levels of biosolids. The same treatments released more nitrogen and resulted in higher percolate nitrate levels. Plants had normal concentrations of all nutrients, except nitrogen, which was low. Heavy metal concentrations were not significantly different among treatments. Based on the analysis of these data, the proportion of biosolids appears to be the most important factor affecting the quality of reconstructed soil and the rate of improvement. The type of coarse material used did not significantly affect the outcome.
A critical analysis of species selection and high vs. low-input silviculture on establishment success and early productivity of model short-rotation wood-energy cropping systems

DOE PAGES

Fischer, M.; Kelley, A. M.; Ward, E. J.; ...

2017-02-03

Most research on bioenergy short rotation woody crops (SRWC) has been dedicated to the genera Populus and Salix. These species generally require relatively high-input culture, including intensive weed competition control, which increases costs and environmental externalities. Widespread native early successional species, characterized by high productivity and good coppicing ability, may be better adapted to local environmental stresses and therefore could offer alternative low-input bioenergy production systems. In order to test this concept, we established a three-year experiment comparing a widely-used hybrid poplar (Populus nigra × P. maximowiczii, clone ‘NM6’) to two native species, American sycamore (Platanus occidentalis L.) and tuliptreemore » (Liriodendron tulipifera L.) grown under contrasting weed and pest control at a coastal plain site in eastern North Carolina, USA. Mean cumulative aboveground wood production was significantly greater in sycamore, with yields of 46.6 Mg ha -11 under high-inputs and 32.7 Mg ha -1 under low-input culture, which rivaled the high-input NM6 yield of 32.9 Mg ha -1. NM6 under low-input management provided noncompetitive yield of 6.2 Mg ha -1. We also found that sycamore showed superiority in survival, biomass increment, weed resistance, treatment convergence, and within-stand uniformity. All are important characteristics for a bioenergy feedstock crop species, leading to reliable establishment and efficient biomass production. Poor performance in all traits was found for tuliptree, with a maximum yield of 1.2 Mg ha -1, suggesting this native species is a poor choice for SRWC. We then conclude that careful species selection beyond the conventionally used genera may enhance reliability and decrease negative environmental impacts of the bioenergy biomass production sector.« less
A critical analysis of species selection and high vs. low-input silviculture on establishment success and early productivity of model short-rotation wood-energy cropping systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, M.; Kelley, A. M.; Ward, E. J.

Most research on bioenergy short rotation woody crops (SRWC) has been dedicated to the genera Populus and Salix. These species generally require relatively high-input culture, including intensive weed competition control, which increases costs and environmental externalities. Widespread native early successional species, characterized by high productivity and good coppicing ability, may be better adapted to local environmental stresses and therefore could offer alternative low-input bioenergy production systems. In order to test this concept, we established a three-year experiment comparing a widely-used hybrid poplar (Populus nigra × P. maximowiczii, clone ‘NM6’) to two native species, American sycamore (Platanus occidentalis L.) and tuliptreemore » (Liriodendron tulipifera L.) grown under contrasting weed and pest control at a coastal plain site in eastern North Carolina, USA. Mean cumulative aboveground wood production was significantly greater in sycamore, with yields of 46.6 Mg ha -11 under high-inputs and 32.7 Mg ha -1 under low-input culture, which rivaled the high-input NM6 yield of 32.9 Mg ha -1. NM6 under low-input management provided noncompetitive yield of 6.2 Mg ha -1. We also found that sycamore showed superiority in survival, biomass increment, weed resistance, treatment convergence, and within-stand uniformity. All are important characteristics for a bioenergy feedstock crop species, leading to reliable establishment and efficient biomass production. Poor performance in all traits was found for tuliptree, with a maximum yield of 1.2 Mg ha -1, suggesting this native species is a poor choice for SRWC. We then conclude that careful species selection beyond the conventionally used genera may enhance reliability and decrease negative environmental impacts of the bioenergy biomass production sector.« less
Drought-induced mortality patterns and rapid biomass recovery in a terra firme forest in the Colombian Amazon.

PubMed

Zuleta, Daniel; Duque, Alvaro; Cardenas, Dairon; Muller-Landau, Helene C; Davies, Stuart J

2017-10-01

Extreme climatic events affecting the Amazon region are expected to become more frequent under ongoing climate change. In this study, we assessed the responses to the 2010 drought of over 14,000 trees ≥10 cm dbh in a 25 ha lowland forest plot in the Colombian Amazon and how these responses varied among topographically defined habitats, with tree size, and with species wood density. Tree mortality was significantly higher during the 2010-2013 period immediately after the drought than in 2007-2010. The post-drought increase in mortality was stronger for trees located in valleys (+243%) than for those located on slopes (+67%) and ridges (+57%). Tree-based generalized linear mixed models showed a significant negative effect of species wood density on mortality and no effect of tree size. Despite the elevated post-drought mortality, aboveground biomass increased from 2007 to 2013 by 1.62 Mg ha -1 yr -1 (95% CI 0.80-2.43 Mg ha -1 yr -1 ). Biomass change varied among habitats, with no significant increase on the slopes (1.05, 95% CI -0.76 to 2.85 Mg ha -1 yr -1 ), a significant increase in the valleys (1.33, 95% CI 0.37-2.34 Mg ha -1 yr -1 ), and a strong increase on the ridges (2.79, 95% CI 1.20-4.21 Mg ha -1 yr -1 ). These results indicate a high carbon resilience of this forest to the 2010 drought due to habitat-associated and interspecific heterogeneity in responses including directional changes in functional composition driven by enhanced performance of drought-tolerant species that inhabit the drier ridges. © 2017 by the Ecological Society of America.
Deadwood stocks increase with selective logging and large tree frequency in Gabon.

PubMed

Carlson, Ben S; Koerner, Sally E; Medjibe, Vincent P; White, Lee J T; Poulsen, John R

2017-04-01

Deadwood is a major component of aboveground biomass (AGB) in tropical forests and is important as habitat and for nutrient cycling and carbon storage. With deforestation and degradation taking place throughout the tropics, improved understanding of the magnitude and spatial variation in deadwood is vital for the development of regional and global carbon budgets. However, this potentially important carbon pool is poorly quantified in Afrotropical forests and the regional drivers of deadwood stocks are unknown. In the first large-scale study of deadwood in Central Africa, we quantified stocks in 47 forest sites across Gabon and evaluated the effects of disturbance (logging), forest structure variables (live AGB, wood density, abundance of large trees), and abiotic variables (temperature, precipitation, seasonality). Average deadwood stocks (measured as necromass, the biomass of deadwood) were 65 Mg ha -1 or 23% of live AGB. Deadwood stocks varied spatially with disturbance and forest structure, but not abiotic variables. Deadwood stocks increased significantly with logging (+38 Mg ha -1 ) and the abundance of large trees (+2.4 Mg ha -1 for every tree >60 cm dbh). Gabon holds 0.74 Pg C, or 21% of total aboveground carbon in deadwood, a threefold increase over previous estimates. Importantly, deadwood densities in Gabon are comparable to those in the Neotropics and respond similarly to logging, but represent a lower proportion of live AGB (median of 18% in Gabon compared to 26% in the Neotropics). In forest carbon accounting, necromass is often assumed to be a constant proportion (9%) of biomass, but in humid tropical forests this ratio varies from 2% in undisturbed forest to 300% in logged forest. Because logging significantly increases the deadwood carbon pool, estimates of tropical forest carbon should at a minimum use different ratios for logged (mean of 30%) and unlogged forests (mean of 18%). © 2016 John Wiley & Sons Ltd.
Tree species diversity promotes aboveground carbon storage through functional diversity and functional dominance.

PubMed

Mensah, Sylvanus; Veldtman, Ruan; Assogbadjo, Achille E; Glèlè Kakaï, Romain; Seifert, Thomas

2016-10-01

The relationship between biodiversity and ecosystem function has increasingly been debated as the cornerstone of the processes behind ecosystem services delivery. Experimental and natural field-based studies have come up with nonconsistent patterns of biodiversity-ecosystem function, supporting either niche complementarity or selection effects hypothesis. Here, we used aboveground carbon (AGC) storage as proxy for ecosystem function in a South African mistbelt forest, and analyzed its relationship with species diversity, through functional diversity and functional dominance. We hypothesized that (1) diversity influences AGC through functional diversity and functional dominance effects; and (2) effects of diversity on AGC would be greater for functional dominance than for functional diversity. Community weight mean (CWM) of functional traits (wood density, specific leaf area, and maximum plant height) were calculated to assess functional dominance (selection effects). As for functional diversity (complementarity effects), multitrait functional diversity indices were computed. The first hypothesis was tested using structural equation modeling. For the second hypothesis, effects of environmental variables such as slope and altitude were tested first, and separate linear mixed-effects models were fitted afterward for functional diversity, functional dominance, and both. Results showed that AGC varied significantly along the slope gradient, with lower values at steeper sites. Species diversity (richness) had positive relationship with AGC, even when slope effects were considered. As predicted, diversity effects on AGC were mediated through functional diversity and functional dominance, suggesting that both the niche complementarity and the selection effects are not exclusively affecting carbon storage. However, the effects were greater for functional diversity than for functional dominance. Furthermore, functional dominance effects were strongly transmitted by CWM of maximum plant height, reflecting the importance of forest vertical stratification for diversity-carbon relationship. We therefore argue for stronger complementary effects that would be induced also by complementary light-use efficiency of tree and species growing in the understory layer.
A large-scale field assessment of carbon stocks in human-modified tropical forests.

PubMed

Berenguer, Erika; Ferreira, Joice; Gardner, Toby Alan; Aragão, Luiz Eduardo Oliveira Cruz; De Camargo, Plínio Barbosa; Cerri, Carlos Eduardo; Durigan, Mariana; Cosme De Oliveira Junior, Raimundo; Vieira, Ima Célia Guimarães; Barlow, Jos

2014-12-01

Tropical rainforests store enormous amounts of carbon, the protection of which represents a vital component of efforts to mitigate global climate change. Currently, tropical forest conservation, science, policies, and climate mitigation actions focus predominantly on reducing carbon emissions from deforestation alone. However, every year vast areas of the humid tropics are disturbed by selective logging, understory fires, and habitat fragmentation. There is an urgent need to understand the effect of such disturbances on carbon stocks, and how stocks in disturbed forests compare to those found in undisturbed primary forests as well as in regenerating secondary forests. Here, we present the results of the largest field study to date on the impacts of human disturbances on above and belowground carbon stocks in tropical forests. Live vegetation, the largest carbon pool, was extremely sensitive to disturbance: forests that experienced both selective logging and understory fires stored, on average, 40% less aboveground carbon than undisturbed forests and were structurally similar to secondary forests. Edge effects also played an important role in explaining variability in aboveground carbon stocks of disturbed forests. Results indicate a potential rapid recovery of the dead wood and litter carbon pools, while soil stocks (0-30 cm) appeared to be resistant to the effects of logging and fire. Carbon loss and subsequent emissions due to human disturbances remain largely unaccounted for in greenhouse gas inventories, but by comparing our estimates of depleted carbon stocks in disturbed forests with Brazilian government assessments of the total forest area annually disturbed in the Amazon, we show that these emissions could represent up to 40% of the carbon loss from deforestation in the region. We conclude that conservation programs aiming to ensure the long-term permanence of forest carbon stocks, such as REDD+, will remain limited in their success unless they effectively avoid degradation as well as deforestation. © 2014 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.
Canopy area of large trees explains aboveground biomass variations across neotropical forest landscapes

NASA Astrophysics Data System (ADS)

Meyer, Victoria; Saatchi, Sassan; Clark, David B.; Keller, Michael; Vincent, Grégoire; Ferraz, António; Espírito-Santo, Fernando; d'Oliveira, Marcus V. N.; Kaki, Dahlia; Chave, Jérôme

2018-06-01

Large tropical trees store significant amounts of carbon in woody components and their distribution plays an important role in forest carbon stocks and dynamics. Here, we explore the properties of a new lidar-derived index, the large tree canopy area (LCA) defined as the area occupied by canopy above a reference height. We hypothesize that this simple measure of forest structure representing the crown area of large canopy trees could consistently explain the landscape variations in forest volume and aboveground biomass (AGB) across a range of climate and edaphic conditions. To test this hypothesis, we assembled a unique dataset of high-resolution airborne light detection and ranging (lidar) and ground inventory data in nine undisturbed old-growth Neotropical forests, of which four had plots large enough (1 ha) to calibrate our model. We found that the LCA for trees greater than 27 m (˜ 25-30 m) in height and at least 100 m2 crown size in a unit area (1 ha), explains more than 75 % of total forest volume variations, irrespective of the forest biogeographic conditions. When weighted by average wood density of the stand, LCA can be used as an unbiased estimator of AGB across sites (R2 = 0.78, RMSE = 46.02 Mg ha-1, bias = -0.63 Mg ha-1). Unlike other lidar-derived metrics with complex nonlinear relations to biomass, the relationship between LCA and AGB is linear and remains unique across forest types. A comparison with tree inventories across the study sites indicates that LCA correlates best with the crown area (or basal area) of trees with diameter greater than 50 cm. The spatial invariance of the LCA-AGB relationship across the Neotropics suggests a remarkable regularity of forest structure across the landscape and a new technique for systematic monitoring of large trees for their contribution to AGB and changes associated with selective logging, tree mortality and other types of tropical forest disturbance and dynamics.
Variation in stem mortality rates determines patterns of above-ground biomass in Amazonian forests: implications for dynamic global vegetation models.

PubMed

Johnson, Michelle O; Galbraith, David; Gloor, Manuel; De Deurwaerder, Hannes; Guimberteau, Matthieu; Rammig, Anja; Thonicke, Kirsten; Verbeeck, Hans; von Randow, Celso; Monteagudo, Abel; Phillips, Oliver L; Brienen, Roel J W; Feldpausch, Ted R; Lopez Gonzalez, Gabriela; Fauset, Sophie; Quesada, Carlos A; Christoffersen, Bradley; Ciais, Philippe; Sampaio, Gilvan; Kruijt, Bart; Meir, Patrick; Moorcroft, Paul; Zhang, Ke; Alvarez-Davila, Esteban; Alves de Oliveira, Atila; Amaral, Ieda; Andrade, Ana; Aragao, Luiz E O C; Araujo-Murakami, Alejandro; Arets, Eric J M M; Arroyo, Luzmila; Aymard, Gerardo A; Baraloto, Christopher; Barroso, Jocely; Bonal, Damien; Boot, Rene; Camargo, Jose; Chave, Jerome; Cogollo, Alvaro; Cornejo Valverde, Fernando; Lola da Costa, Antonio C; Di Fiore, Anthony; Ferreira, Leandro; Higuchi, Niro; Honorio, Euridice N; Killeen, Tim J; Laurance, Susan G; Laurance, William F; Licona, Juan; Lovejoy, Thomas; Malhi, Yadvinder; Marimon, Bia; Marimon, Ben Hur; Matos, Darley C L; Mendoza, Casimiro; Neill, David A; Pardo, Guido; Peña-Claros, Marielos; Pitman, Nigel C A; Poorter, Lourens; Prieto, Adriana; Ramirez-Angulo, Hirma; Roopsind, Anand; Rudas, Agustin; Salomao, Rafael P; Silveira, Marcos; Stropp, Juliana; Ter Steege, Hans; Terborgh, John; Thomas, Raquel; Toledo, Marisol; Torres-Lezama, Armando; van der Heijden, Geertje M F; Vasquez, Rodolfo; Guimarães Vieira, Ima Cèlia; Vilanova, Emilio; Vos, Vincent A; Baker, Timothy R

2016-12-01

Understanding the processes that determine above-ground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody productivity [woody net primary productivity (NPP)] and the rate at which carbon is lost through tree mortality. Here, we test whether two direct metrics of tree mortality (the absolute rate of woody biomass loss and the rate of stem mortality) and/or woody NPP, control variation in AGB among 167 plots in intact forest across Amazonia. We then compare these relationships and the observed variation in AGB and woody NPP with the predictions of four DGVMs. The observations show that stem mortality rates, rather than absolute rates of woody biomass loss, are the most important predictor of AGB, which is consistent with the importance of stand size structure for determining spatial variation in AGB. The relationship between stem mortality rates and AGB varies among different regions of Amazonia, indicating that variation in wood density and height/diameter relationships also influences AGB. In contrast to previous findings, we find that woody NPP is not correlated with stem mortality rates and is weakly positively correlated with AGB. Across the four models, basin-wide average AGB is similar to the mean of the observations. However, the models consistently overestimate woody NPP and poorly represent the spatial patterns of both AGB and woody NPP estimated using plot data. In marked contrast to the observations, DGVMs typically show strong positive relationships between woody NPP and AGB. Resolving these differences will require incorporating forest size structure, mechanistic models of stem mortality and variation in functional composition in DGVMs. © 2016 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.
Bioinspired Nanocellulose Based Hybrid Materials With Novel Interfacial Properties

NASA Astrophysics Data System (ADS)

Keten, Sinan

This talk will overview a simulation-based approach to enhancing the mechanical properties of nanocomposites by utilizing cellulose - the most abundant and renewable structural biopolymer found on our planet. Cellulose nanocrystals (CNCs) exhibit outstanding mechanical properties exceeding that of Kevlar, serving as reinforcing domains in nature's toughest hierarchical nanocomposites such as wood. Yet, weak interfaces at the surfaces of CNCs have so far made it impossible to scale these inherent properties to macroscopic systems. In this work, I will discuss how surface functionalization of CNCs influences their properties in their self-assembled films and nanocomposites with engineered polymer matrices . Specifically, the role of ion exchange based surface modifications and polymer conjugation will be discussed, where atomistic and coarse-grained simulations will reveal new insights into how superior mechanical properties can potentially be attained by hybrid constructs.
Aboveground predation by an American badger (Taxidea taxus) on black-tailed prairie dogs (Cynomys ludovicianus)

USGS Publications Warehouse

Eads, D.A.; Biggins, D.E.

2008-01-01

During research on black-tailed prairie dogs (Cynomys ludovicianus), we repeatedly observed a female American badger (Taxidea taxus) hunting prairie dogs on a colony in southern Phillips County, Montana. During 1-14 June 2006, we observed 7 aboveground attacks (2 successful) and 3 successful excavations of prairie dogs. The locations and circumstances of aboveground attacks suggested that the badger improved her probability of capturing prairie dogs by planning the aboveground attacks based on perceptions of speeds, angles, distances, and predicted escape responses of prey. Our observations add to previous reports on the complex and varied predatory methods and cognitive capacities of badgers. These observations also underscore the individuality of predators and support the concept that predators are active participants in predator-prey interactions.
How to improve fertility of African soils? Leguminous fallows (Cameroon), addition of farmyard manure and mineral fertilizer (Kenya), organic residues management and introduction of N2 fixing species in forest plantations (Congo).

NASA Astrophysics Data System (ADS)

Koutika, Lydie-Stella; Mareschal, Louis; Mouanda, Cadeau; Epron, Daniel

2014-05-01

Most of African soils are inherently infertile and poor in nutrients mainly nitrogen and phosphorus. Several practices are used to improve soil fertility, increase productivity and ensure their sustainability. Soil fertility in the leguminous fallows was evaluated through particulate organic matter (POM), the more active part of soil organic matter (SOM) in Cameroon. The combination of mineral and organic (manure) fertilizers increased microbial P biomass allowing the release of P along the plant growing period in the Kenyan soils. Organic residues management and introduction of nitrogen fixing species (Acacia) were used to improve soil fertility and sustain forest productivity on the coastal plains of Congo. SOM fractionation was made under Pueraria, Mucuna fallows and natural regrowth mainly Chromolaena and under 3 forest plantation treatments installed in previous savanna: 1) no input, 2) normal input, and 3) double input of organic residues. Microbial P biomass and sequential P fractionation were evaluated in high and low P fixing soils. N, C, available P and pH were determined on soil sampled in acacia (100A), eucalypt (100E) and mixed-species (50A:50E) stands. N and P were determined in aboveground litters and in leaves, bark and wood of trees. The two leguminous fallows increased N content in POM fractions i.e., N >1% for Pueraria and Mucuna against N<1% for natural regrowth in the 0-0.10m depth, probably through N input from N2 fixation from the atmosphere (Cameroon).The addition of mineral fertilizers and farmyard manure increases P biomass (4.8 after 2 weeks to 15.2 after 16 weeks), and then decreased to 9.7 mg P g-1 soil (week 32). It also changes the P Hedley fractions partition in the high P fixing Kenyan soil (0-0.10m). After two rotations (14 years), SOM mineralization was the highest in the double input of organic residues treatment (low coarse POM 5.6 g kg-1 of soil and high organo-mineral fraction (OMF) 115 g kg-1 of soil). The introduction of A. mangium in eucalypt plantations increased the soil N concentration under the mixed-species stand (N>0.06%) compared to under the pure eucalypt stand (N<0.05%) in the 0-0.05 m, along with an increase in soil C concentration (C>1% in the mixed stand and C< 0.9 in the pure Eucalyptus stand).
Characterization of black carbon and organic contaminants in wood ash from different feedstocks and types of furnaces

NASA Astrophysics Data System (ADS)

Merino, Agustin; Rey-Salgueiro, Ledicia; Omil, Beatriz; Martinez-Carballo, Elena; Simal-Gandara, Jesus

2015-04-01

Due to their important concentration of nutrient and charcoal, wood ash from biomass power plants (WA) can be used as a fertilizer and organic amendment in intensively managed soils. Unlike biochar produced in under anoxic conditions, the nature of the organic compounds present in wood ash has been scarcely studied. Due to the incomplete combustion, wood ash may contain a wide range of organic compounds, from charred to highly condensed refractory biomass, which determines the possibilities of WA as an organic amendment. In addition, the possible environmental risk of this practice must be assessed by determining the content of water-soluble and insoluble organic contaminants. due to the incomplete combustion of organic matter, organic pollutants, such as Polycyclic Aromatic Hydrocarbons (PAHs), can be formed and can remain in the combustion residue. Also, the four alkyl benzene volatile organic compounds (benzene, toluene, ethylbenzene, and the ortho, para, and meta xylenes) can be formed, depending on certain conditions during combustion. For this study 15 biomass power stations in Spain were selected. In all of them the feedstock is pine or eucalyptus branches and bark. Nine of them were bottom wood ash generated from wood fires furnaces, obtained from grate-fired or water-tube boilers. Whereas four of them were fly ash, obtained in cyclone separators. The samples were collected following a common procedure to ensure the representiveness of the sampling. Bottom ash samples were fraccionated in three fractions: < 2mm, 2-5 mm and > 5mm. Each fraction was characterized for organic matter and BTEX, styrene and total petroleum hydrocarbons Polycyclic Aromatic Hydrocarbons. For each analyzes, three replicates were analyzed per sample. Mixes wood ash shows higher amounts of charred material than fly ash. The 13 C CPMAS NMR, DSC/TG and FTIR analysis showed the loss of carbohydrates and aliphatic constituents and revealed the formation of aromatic compounds. The atomic H/C ratios, NMR spectra, DSC and FTIR confirmed the presence of condensed structures, specially in the coarse particles. However, the different wood ash showed an important range of properties revealing the presence from charred material to charcoal containing condensed structures (H/C ratios lower than 0.6; aromaticity higher than 80 % and T50-DSC higher than 500 °C). Typical organic pollutants including those water-soluble such as BTEX plus styrene, but also those water-insoluble such as polycyclic aromatic hydrocarbons (PAHs), together with aliphatic hydrocarbons, were examined in the ash. Their contents were related to degree of combustion of the biomass, determined through the content and composition of the organic matter in the wood ash. The sum of BTEX plus styrene varied from non-detected to 30 mg/kg, and the total amounts of PAHs (total PAHs) ranged between non-detected and 422 µg/kg, not exceeding the regulated limits. This research provides basic information for the evaluation of the environmental risk and potential uses of WW incinerator bottom ash The results demonstrate the important variability in the charred material properties of the different power plants and size-particles. The organic compounds contents are also variable, but in all cases were levels of pollutants in all the samples were below the limits for both soil and industrial use (Environmental Protection Agency in the European Union and the USA.
Proven Alternatives for Aboveground Treatment of Arsenic in Groundwater

EPA Pesticide Factsheets

This issue paper, developed for EPA's Engineering Forum, identifies and summarizes experiences with proven aboveground treatment alternatives for arsenic in groundwater, and provides information on their relative effectiveness and cost.
Flow-sediment-large woody debris interplay: Introducing an appropriately scaled laboratory experiment

NASA Astrophysics Data System (ADS)

Friedrich, H.; Spreitzer, G.; Tunnicliffe, J. F.

2017-12-01

The morphology of steep (>0.01 m/m) forested streams is governed not only by water-sediment interplay, but also by accumulations of coarse and fine organic debris. In this project we look at the jamming dynamics (formation, persistence and hydraulic feedbacks) of large woody debris with the help of scaled laboratory experiments. In New Zealand, the recruitment of wood from both natural tree-fall and forest harvesting has led to obstruction of culverts, bridges and other river constrictions. Understanding the dynamics of jam formation and persistence is important for harvest practice guidelines, management of sediment accumulation, as well as establishing impacts to habitat and infrastructure. In this study, we provide the context of our work, present our experimental setup for studying the complex flow-sediment-wood interactions and present some initial results. In our experimental setup, we varied feed rates of sediment and organic fine material in order to establish concentration thresholds for jam formation, and development of sediment retention capacity upstream of the jam. Large woody debris accumulation is studied for different blocking scenarios, and the effect on sediment transport is measured. Sediment quantities and changes in channel bed morphology upstream of the critical cross section are evaluated, together with resulting backwater effects, and associated energy losses. In the long term, our results will inform our understanding of the processes that take place from the mobilization of woody debris to accumulation.
Longitudinal distribution and parameters of large wood in a Mediterranean ephemeral stream

NASA Astrophysics Data System (ADS)

Galia, T.; Škarpich, V.; Tichavský, R.; Vardakas, L.; Šilhán, K.

2018-06-01

Although large wood (LW) has been intensively studied in forested basins of humid temperate climates, data on LW patterns in different fluvial environments are rather scarce. Therefore, we investigated the dimensions, characteristics, longitudinal distribution, and dynamics of LW along a 4.05-km-long reach of an ephemeral channel typical of European Mediterranean mountainous landscape (Sfakiano Gorge, Crete, Greece). We analysed a total of 795 LW pieces, and the mean observed abundance of LW was generally lower (14.3 m3/ha of active valley floor or 19.6 LW pieces/100 m of stream length) than is usually documented for more humid environments. The number of LW pieces was primarily controlled by trees growing on the valley floor. These living trees acted as important LW supply agents (by tree throws or the supply of individual branches with sufficient LW dimensions) and flow obstructions during large flood events, causing storage of transported LW pieces in jams. However, the downstream transport of LW is probably episodic, and large jams are likely formed only during major floods; after >15 years, we still observed significant imprints of the last major flood event on the present distribution of LW. The geomorphic function of LW in the studied stream can only be perceived to be a spatially limited stabilising element for sediments, which was documented by a few accumulations of coarse clastic material by LW steps and jams.
Estimating Above-Ground Carbon Biomass in a Newly Restored Coastal Plain Wetland Using Remote Sensing

PubMed Central

Riegel, Joseph B.; Bernhardt, Emily; Swenson, Jennifer

2013-01-01

Developing accurate but inexpensive methods for estimating above-ground carbon biomass is an important technical challenge that must be overcome before a carbon offset market can be successfully implemented in the United States. Previous studies have shown that LiDAR (light detection and ranging) is well-suited for modeling above-ground biomass in mature forests; however, there has been little previous research on the ability of LiDAR to model above-ground biomass in areas with young, aggrading vegetation. This study compared the abilities of discrete-return LiDAR and high resolution optical imagery to model above-ground carbon biomass at a young restored forested wetland site in eastern North Carolina. We found that the optical imagery model explained more of the observed variation in carbon biomass than the LiDAR model (adj-R2 values of 0.34 and 0.18 respectively; root mean squared errors of 0.14 Mg C/ha and 0.17 Mg C/ha respectively). Optical imagery was also better able to predict high and low biomass extremes than the LiDAR model. Combining both the optical and LiDAR improved upon the optical model but only marginally (adj-R2 of 0.37). These results suggest that the ability of discrete-return LiDAR to model above-ground biomass may be rather limited in areas with young, small trees and that high spatial resolution optical imagery may be the better tool in such areas. PMID:23840837
MODIS Based Estimation of Forest Aboveground Biomass in China.

PubMed

Yin, Guodong; Zhang, Yuan; Sun, Yan; Wang, Tao; Zeng, Zhenzhong; Piao, Shilong

2015-01-01

Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS) dataset in a machine learning algorithm (the model tree ensemble, MTE). We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha-1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y-1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y-1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y-1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests.
MODIS Based Estimation of Forest Aboveground Biomass in China

PubMed Central

Sun, Yan; Wang, Tao; Zeng, Zhenzhong; Piao, Shilong

2015-01-01

Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS) dataset in a machine learning algorithm (the model tree ensemble, MTE). We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha−1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y−1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y−1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y−1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests. PMID:26115195

Preliminary study on the relationships between aboveground storage and remotely sensed data at Pingdong plain afforestation land in Southern Taiwan

NASA Astrophysics Data System (ADS)

Wei, C.; Chen, J. M.; Yu, J.; Cheng, C.; Lai, Y.; Chiang, P.; Hong, C.; Chang, C.; Wey, T.; Tsai, M.; Wang, Y.

2013-12-01

This research aims on the relationships between LAI and five vegetation index (BR, SRBR, BD, NDVI and TNDVI) from remotely sensed images, in situ measurements and aboveground storage for 10-11yr old plain afforestation (14 species) located at Wanlong farm of subtropical-tropical region at the southern part of Taiwan which originally governed by Taiwan Sugar Corporation. The preliminary results show the aboveground storage is 14.19×9.19 m3 ha-1 and the correlation coefficient between aboveground storage and BR, SRBR, BD, NDVI and TNDVI is 0.331 (p=0.211), 0.317 (p=0.232), 0.310 (p=0.244), 0.714 (p=0.002) and 0.706 (p=0.002) while NDVI performs the best correlation. LAI value using Fisheye or Tracing Radiation and Architecture of Canopies (TRAC) is 0.76×0.37 and 3.89×2.81, respectively. Besides, CI measured by TRAC is 0.83×0.09 and the correlation coefficient with LAI is 0.868 (p<0.001). It shows feasible to estimate aboveground storage using ground investigation incorporating remotely sensed data for young plain afforestation stand. Due to the mixed-plantation and difference between growing and non-growing season at the sample site, the relationship between aboveground storage, LAI and VI is yet to be developed for independent species and may need to modify due to seasonally and inter-annually variation.
Maize (Zea mays) seeds can detect above-ground weeds; thiamethoxam alters the view.

PubMed

Afifi, Maha; Lee, Elizabeth; Lukens, Lewis; Swanton, Clarence

2015-09-01

Far red light is known to penetrate soil and delay seed germination. Thiamethoxam as a seed treatment has been observed to enhance seed germination. No previous work has explored the effect of thiamethoxam on the physiological response of buried maize seed when germinating in the presence of above-ground weeds. We hypothesised that the changes in red:far red reflected from above-ground weeds would be detected by maize seed phytochrome and delay seed germination by decreasing the level of GA and increasing ABA. We further hypothesised that thiamethoxam would overcome this delay in germination. Thiamethoxam enhanced seed germination in the presence of above-ground weeds by increasing GA signalling and downregulating DELLA protein and ABA signalling genes. An increase in amylase activity and a degradation of starch were also observed. Far red reflected from the above-ground weeds was capable of penetrating below the soil surface and was detected by maize seed phytochrome. Thiamethoxam altered the effect of far red on seed germination by stimulating GA and inhibiting ABA synthesis. This is the first study to suggest that the mode of action of thiamethoxam involves both GA synthesis and ABA inhibition. © 2014 Society of Chemical Industry.
Linkages between below and aboveground communities: Decomposer responses to simulated tree species loss are largely additive.

Treesearch

Becky A. Ball; Mark A. Bradford; Dave C. Coleman; Mark D. Hunter

2009-01-01

Inputs of aboveground plant litter influence the abundance and activities of belowground decomposer biota. Litter-mixing studies have examined whether the diversity and heterogeneity of litter inputs...
Evaluation and Validation of Aboveground Techniques for Coating Condition Assessment

DOT National Transportation Integrated Search

2006-02-28

The overall objective was to determine the accuracy, resolution, and limitations of equipment typically used for modern aboveground ECDA work with respect to locating holidays and disbondments with commonly used coatings with varying spatial relation...
Remote Sensing of a Manipulated Prairie Grassland Experiment to Predict Belowground Processes

NASA Astrophysics Data System (ADS)

Cavender-Bares, J.; Schweiger, A. K.; Hobbie, S. E.; Madritch, M. D.; Wang, Z.; Couture, J. J.; Gamon, J. A.; Townsend, P. A.

2017-12-01

Given the importance of plant biodiversity for providing the ecosystem functions and services on which humans depend, rapid and remote methods of monitoring plant biodiversity across large spatial extents and biological scales are increasingly critical. In North American prairie systems, the ecosystem benefits of diversity are a subject of ongoing investigation and relevance to policy. However, detecting belowground components of ecosystem biodiversity, composition and associated functions are not possible directly through remote sensing. Nevertheless, belowground components of diversity may be linked to aboveground components allowing indirect inferences. Here we test a series of hypotheses about how aboveground functional and chemical diversity and composition of plant communities drive belowground functions, including N mineralization, enzyme activity and microbial biomass, as well as microbial diversity and composition. We hypothesize that the quantity and chemical composition of aboveground inputs to soil drive belowground processes, including decomposition and microbial enzyme activity. We use plant spectra (400 nm to 2500 nm) measured at the leaf and airborne level to determine chemical and functional composition of leaves and canopies in a long-term grassland experiment where diversity is manipulated at the Cedar Creek Ecosystem Science Reserve. We then assess the extent to which belowground chemistry, microbial diversity and composition are predicted from aboveground plant diversity, biomass and chemical composition. We find strong associations between aboveground inputs and belowground enzyme activity and microbial biomass but only weak linkages between aboveground diversity and belowground diversity. We discuss the potential for such approaches and the caveats related to the spatial scale of measurements and spatial resolution of airborne detection.
Standing crop and aboveground biomass partitioning of a dwarf mangrove forest in Taylor River Slough, Florida

USGS Publications Warehouse

Coronado-Molina, C.; Day, J.W.; Reyes, E.; Perez, B.C.

2004-01-01

The structure and standing crop biomass of a dwarf mangrove forest, located in the salinity transition zone ofTaylor River Slough in the Everglades National Park, were studied. Although the four mangrove species reported for Florida occurred at the study site, dwarf Rhizophora mangle trees dominated the forest. The structural characteristics of the mangrove forest were relatively simple: tree height varied from 0.9 to 1.2 meters, and tree density ranged from 7062 to 23 778 stems haa??1. An allometric relationship was developed to estimate leaf, branch, prop root, and total aboveground biomass of dwarf Rhizophora mangle trees. Total aboveground biomass and their components were best estimated as a power function of the crown area times number of prop roots as an independent variable (Y = B ?? Xa??0.5083). The allometric equation for each tree component was highly significant (p<0.0001), with all r2 values greater than 0.90. The allometric relationship was used to estimate total aboveground biomass that ranged from 7.9 to 23.2 ton haa??1. Rhizophora mangle contributed 85% of total standing crop biomass. Conocarpus erectus, Laguncularia racemosa, and Avicennia germinans contributed the remaining biomass. Average aboveground biomass allocation was 69% for prop roots, 25% for stem and branches, and 6% for leaves. This aboveground biomass partitioning pattern, which gives a major role to prop roots that have the potential to produce an extensive root system, may be an important biological strategy in response to low phosphorus availability and relatively reduced soils that characterize mangrove forests in South Florida.
Cadmium uptake in above-ground parts of lettuce (Lactuca sativa L.).

PubMed

Tang, Xiwang; Pang, Yan; Ji, Puhui; Gao, Pengcheng; Nguyen, Thanh Hung; Tong, Yan'an

2016-03-01

Because of its high Cd uptake and translocation, lettuce is often used in Cd contamination studies. However, there is a lack of information on Cd accumulation in the above-ground parts of lettuce during the entire growing season. In this study, a field experiment was carried out in a Cd-contaminated area. Above-ground lettuce parts were sampled, and the Cd content was measured using a flame atomic absorption spectrophotometer (AAS). The results showed that the Cd concentration in the above-ground parts of lettuce increased from 2.70 to 3.62mgkg(-1) during the seedling stage, but decreased from 3.62 to 2.40mgkg(-1) during organogenesis and from 2.40 to 1.64mgkg(-1) during bolting. The mean Cd concentration during the seedling stage was significantly higher than that during organogenesis (a=0.05) and bolting (a=0.01). The Cd accumulation in the above-ground parts of an individual lettuce plant could be described by a sigmoidal curve. Cadmium uptake during organogenesis was highest (80% of the total), whereas that during bolting was only 4.34%. This research further reveals that for Rome lettuce: (1) the highest Cd content of above-ground parts occurred at the end of the seedling phase; (2) the best harvest time with respect to Cd phytoaccumulation is at the end of the organogenesis stage; and (3) the organogenesis stage is the most suitable time to enhance phytoaccumulation efficiency by adjusting the root:shoot ratio. Copyright © 2015 Elsevier Inc. All rights reserved.
Northern Victoria Land (western Ross Sea-Antarctica): inner shelf fine sedimentation

NASA Astrophysics Data System (ADS)

Colizza, E.; Finocchiaro, F.; Ivaldi, R.; Pittà, A.; Tolotti, R.; Brambati, A.

2003-04-01

The Holocene sedimentation conditions are represented, in the western Ross Sea, by diatomaceous ooze in the uppermost part of sedimentary sequences, while diamicton deposited during Last Glacial Maximum are the basal unit of most cores. Thick layer (> 2 m) of diatomaceous ooze were sampled in the northern Joides Basin and into Granite Harbour. In Drygalski Ice Tongue area and along the coasts of northern Victoria Land, prevails coarse sedimentation, due to seaward flowing of large outlet glacier that drain the Transantarctic Mountain. During 1998-99 and 2001-02 PNRA antarctic cruises, favourable sea ice conditions, has allowed to sample inner shelf area, both in Wood Bay and south of Drygalski ice tongue (Nordenskjold basin). In both sites fine laminated diatomaceous mud are present. Preliminary seismostratigraphy and sedimentological data are here reported. This is the first note of new sites of fine sedimentation in the Ross Sea inner shelf.
Above-ground biomass and structure of pristine Siberian Scots pine forests as controlled by competition and fire.

PubMed

Wirth, C; Schulze, E-D; Schulze, W; von Stünzner-Karbe, D; Ziegler, W; Miljukova, I M; Sogatchev, A; Varlagin, A B; Panvyorov, M; Grigoriev, S; Kusnetzova, W; Siry, M; Hardes, G; Zimmermann, R; Vygodskaya, N N

1999-10-01

The study presents a data set of above-ground biomass (AGB), structure, spacing and fire regime, for 24 stands of pristine Siberian Scots pine (Pinus sylvestris) forests with lichens (n = 20) or Vaccinium/mosses (n = 4) as ground cover, along four chronosequences. The stands of the "lichen" site type (LT) were stratified into three chronosequences according to stand density and fire history. Allometric equations were established from 90 sample trees for stem, coarse branch, fine branch, twig and needle biomass. The LT stands exhibited a low but sustained biomass accumulation until a stand age of 383 years. AGB reached only 6-10 kg dw m -2 after 200 years depending on stand density and fire history compared to 20 kg dw m -2 in the "Vaccinium" type (VT) stands. Leaf area index (LAI) in the LT stands remained at 0.5-1.5 and crown cover was 30-60%, whereas LAI reached 2.5 and crown cover was >100% in the VT stands. Although nearest-neighbour analyses suggested the existence of density-dependent mortality, fire impact turned out to have a much stronger effect on density dynamics. Fire scar dating and calculation of mean and initial fire return intervals revealed that within the LT stands differences in structure and biomass were related to the severity of fire regimes, which in turn was related to the degree of landscape fragmentation by wetlands. Self-thinning analysis was used to define the local carrying capacity for biomass. A series of undisturbed LT stands was used to characterise the upper self-thinning boundary. Stands that had experienced a moderate fire regime were positioned well below the self-thinning boundary in a distinct fire-thinning band of reduced major axis regression slope -0.26. We discuss how this downward shift resulted from alternating phases of density reduction by fire and subsequent regrowth. We conclude that biomass in Siberian Scots pine forests is strongly influenced by fire and that climate change will affect ecosystem functions predominantly via changes in fire regimes.
Spatial Structure of Above-Ground Biomass Limits Accuracy of Carbon Mapping in Rainforest but Large Scale Forest Inventories Can Help to Overcome

PubMed Central

Guitet, Stéphane; Hérault, Bruno; Molto, Quentin; Brunaux, Olivier; Couteron, Pierre

2015-01-01

Precise mapping of above-ground biomass (AGB) is a major challenge for the success of REDD+ processes in tropical rainforest. The usual mapping methods are based on two hypotheses: a large and long-ranged spatial autocorrelation and a strong environment influence at the regional scale. However, there are no studies of the spatial structure of AGB at the landscapes scale to support these assumptions. We studied spatial variation in AGB at various scales using two large forest inventories conducted in French Guiana. The dataset comprised 2507 plots (0.4 to 0.5 ha) of undisturbed rainforest distributed over the whole region. After checking the uncertainties of estimates obtained from these data, we used half of the dataset to develop explicit predictive models including spatial and environmental effects and tested the accuracy of the resulting maps according to their resolution using the rest of the data. Forest inventories provided accurate AGB estimates at the plot scale, for a mean of 325 Mg.ha-1. They revealed high local variability combined with a weak autocorrelation up to distances of no more than10 km. Environmental variables accounted for a minor part of spatial variation. Accuracy of the best model including spatial effects was 90 Mg.ha-1 at plot scale but coarse graining up to 2-km resolution allowed mapping AGB with accuracy lower than 50 Mg.ha-1. Whatever the resolution, no agreement was found with available pan-tropical reference maps at all resolutions. We concluded that the combined weak autocorrelation and weak environmental effect limit AGB maps accuracy in rainforest, and that a trade-off has to be found between spatial resolution and effective accuracy until adequate “wall-to-wall” remote sensing signals provide reliable AGB predictions. Waiting for this, using large forest inventories with low sampling rate (<0.5%) may be an efficient way to increase the global coverage of AGB maps with acceptable accuracy at kilometric resolution. PMID:26402522
The importance of forest structure to biodiversity–productivity relationships

PubMed Central

Huth, Andreas

2017-01-01

While various relationships between productivity and biodiversity are found in forests, the processes underlying these relationships remain unclear and theory struggles to coherently explain them. In this work, we analyse diversity–productivity relationships through an examination of forest structure (described by basal area and tree height heterogeneity). We use a new modelling approach, called ‘forest factory’, which generates various forest stands and calculates their annual productivity (above-ground wood increment). Analysing approximately 300 000 forest stands, we find that mean forest productivity does not increase with species diversity. Instead forest structure emerges as the key variable. Similar patterns can be observed by analysing 5054 forest plots of the German National Forest Inventory. Furthermore, we group the forest stands into nine forest structure classes, in which we find increasing, decreasing, invariant and even bell-shaped relationships between productivity and diversity. In addition, we introduce a new index, called optimal species distribution, which describes the ratio of realized to the maximal possible productivity (by shuffling species identities). The optimal species distribution and forest structure indices explain the obtained productivity values quite well (R2 between 0.7 and 0.95), whereby the influence of these attributes varies within the nine forest structure classes. PMID:28280550
Surface radiological investigations at White Wing Scrap Yard, Oak Ridge Reservation, Oak Ridge, Tennessee

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, J.K.; Rodriguez, R.E.; Uziel, M.S.

1991-09-01

A surface radiological scoping survey of accessible areas at the White Wing Scrap Yard (Waste Area Grouping 11 (WAG 11)) was conducted intermittently from December 1989 through July 1991 by members of the Measurement Applications and Development Group, Health and Safety Research Division, Oak Ridge National Laboratory (ORNL) at the request of Environmental Restoration Program personnel at ORNL. The White Wing Scrap Yard is an estimated 30-acre, predominately wooded area located on the western edge of East Fork Ridge in the McNew Hollow area on the US Department of Energy's Oak Ridge Reservation. The scrap yard was formerly used formore » aboveground storage of contaminated material (e.g., steel tanks, metal, glass, concrete, and miscellaneous industrial trash) from the Oak Ridge K-25 Site, Oak Ridge Y-12 Plant, and ORNL. The purposes of this cursory investigation were (1) to provide an updated contamination status of the site by locating and interpreting the presence, nature, and extent of surface radiological contamination and (2) to provide a basis for the formulation of interim corrective action to limit human exposures to radioactivity and minimize the potential for contaminant dispersion. 13 refs., 17 figs., 5 tabs.« less
NORTH ELEVATION WITH GRADUATED MEASURING POLE. ABOVEGROUND PORTION IS ON ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

NORTH ELEVATION WITH GRADUATED MEASURING POLE. ABOVE-GROUND PORTION IS ON THE LEFT. VIEW FACING SOUTH - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, Battery Command Center, Ford Island, Pearl City, Honolulu County, HI
Elicitors aboveground: an alternative for control of a belowground pest

USDA-ARS?s Scientific Manuscript database

Plant defense pathways mediate multitrophic interactions above and belowground. Understanding the effects of these pathways on pests and natural enemies above and belowground holds great potential for designing effective control strategies. Here we investigate the effects of aboveground stimulation ...
Interactions between aboveground herbivores and the mycorrhizal mutualists of plants.

PubMed

Gehring, C A; Whitham, T G

1994-07-01

Plant growth, reproduction and survival can be affected both by mycorrhizal fungi and aboveground herbivores, but few studies have examined the interactive effects of these factors on plants. Most of the available data suggest that severe herbivory reduces root colonization by vesicular-arbuscular and ectomycorrhizal fungi. However, the reverse interaction has also been documented - mycorrhizal fungi deter herbivores and interact with fungal endophytes to influence herbivory. Although consistent patterns and mechanistic explanations are yet to emerge, it is likely that aboveground herbivore-mycorrhiza interactions have important implications for plant populations and communities. Copyright © 1994. Published by Elsevier Ltd.
Soil Moisture Limitations on Monitoring Boreal Forest Regrowth Using Spaceborne L-Band SAR Data

NASA Technical Reports Server (NTRS)

Kasischke, Eric S.; Tanase, Mihai A.; Bourgeau-Chavez, Laura L.; Borr, Matthew

2011-01-01

A study was carried out to investigate the utility of L-band SAR data for estimating aboveground biomass in sites with low levels of vegetation regrowth. Data to estimate biomass were collected from 59 sites located in fire-disturbed black spruce forests in interior Alaska. PALSAR L-band data (HH and HV polarizations) collected on two dates in the summer/fall of 2007 and one date in the summer of 2009 were used. Significant linear correlations were found between the log of aboveground biomass (range of 0.02 to 22.2 t ha-1) and (L-HH) and (L-HV) for the data collected on each of the three dates, with the highest correlation found using the LHV data collected when soil moisture was highest. Soil moisture, however, did change the correlations between L-band and aboveground biomass, and the analyses suggest that the influence of soil moisture is biomass dependent. The results indicate that to use L-band SAR data for mapping aboveground biomass and monitoring forest regrowth will require development of approaches to account for the influence that variations in soil moisture have on L-band microwave backscatter, which can be particularly strong when low levels of aboveground biomass occur
Impact of logging on aboveground biomass stocks in lowland rain forest, Papua New Guinea.

PubMed

Bryan, Jane; Shearman, Phil; Ash, Julian; Kirkpatrick, J B

2010-12-01

Greenhouse-gas emissions resulting from logging are poorly quantified across the tropics. There is a need for robust measurement of rain forest biomass and the impacts of logging from which carbon losses can be reliably estimated at regional and global scales. We used a modified Bitterlich plotless technique to measure aboveground live biomass at six unlogged and six logged rain forest areas (coupes) across two approximately 3000-ha regions at the Makapa concession in lowland Papua New Guinea. "Reduced-impact logging" is practiced at Makapa. We found the mean unlogged aboveground biomass in the two regions to be 192.96 +/- 4.44 Mg/ha and 252.92 +/- 7.00 Mg/ha (mean +/- SE), which was reduced by logging to 146.92 +/- 4.58 Mg/ha and 158.84 +/- 4.16, respectively. Killed biomass was not a fixed proportion, but varied with unlogged biomass, with 24% killed in the lower-biomass region, and 37% in the higher-biomass region. Across the two regions logging resulted in a mean aboveground carbon loss of 35 +/- 2.8 Mg/ha. The plotless technique proved efficient at estimating mean aboveground biomass and logging damage. We conclude that substantial bias is likely to occur within biomass estimates derived from single unreplicated plots.
Leaf mass per area, not total leaf area, drives differences in above-ground biomass distribution among woody plant functional types.

PubMed

Duursma, Remko A; Falster, Daniel S

2016-10-01

Here, we aim to understand differences in biomass distribution between major woody plant functional types (PFTs) (deciduous vs evergreen and gymnosperm vs angiosperm) in terms of underlying traits, in particular the leaf mass per area (LMA) and leaf area per unit stem basal area. We used a large compilation of plant biomass and size observations, including observations of 21 084 individuals on 656 species. We used a combination of semiparametric methods and variance partitioning to test the influence of PFT, plant height, LMA, total leaf area, stem basal area and climate on above-ground biomass distribution. The ratio of leaf mass to above-ground woody mass (MF /MS ) varied strongly among PFTs. We found that MF /MS at a given plant height was proportional to LMA across PFTs. As a result, the PFTs did not differ in the amount of leaf area supported per unit above-ground biomass or per unit stem basal area. Climate consistently explained very little additional variation in biomass distribution at a given plant size. Combined, these results demonstrate consistent patterns in above-ground biomass distribution and leaf area relationships among major woody PFTs, which can be used to further constrain global vegetation models. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.
Final Harvest of Above-Ground Biomass and Allometric Analysis of the Aspen FACE Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mark E. Kubiske

The Aspen FACE experiment, located at the US Forest Service Harshaw Research Facility in Oneida County, Wisconsin, exposes the intact canopies of model trembling aspen forests to increased concentrations of atmospheric CO2 and O3. The first full year of treatments was 1998 and final year of elevated CO2 and O3 treatments is scheduled for 2009. This proposal is to conduct an intensive, analytical harvest of the above-ground parts of 24 trees from each of the 12, 30 m diameter treatment plots (total of 288 trees) during June, July & August 2009. This above-ground harvest will be carefully coordinated with themore » below-ground harvest proposed by D.F. Karnosky et al. (2008 proposal to DOE). We propose to dissect harvested trees according to annual height growth increment and organ (main stem, branch orders, and leaves) for calculation of above-ground biomass production and allometric comparisons among aspen clones, species, and treatments. Additionally, we will collect fine root samples for DNA fingerprinting to quantify biomass production of individual aspen clones. This work will produce a thorough characterization of above-ground tree and stand growth and allocation above ground, and, in conjunction with the below ground harvest, total tree and stand biomass production, allocation, and allometry.« less
BELOWGROUND NITROGEN UPTAKE AND ALLOCATION ...

EPA Pesticide Factsheets

Anthropogenic nitrogen inputs coupled with rising sea level complicate predictions of marsh stability. As marsh stability is a function of its vegetation, it is important to understand the mechanisms that drive community dynamics. Many studies have examined aboveground dynamics and nutrient cycling, but few have studied the belowground uptake and allocation of nitrogen. Literature suggests that D. spicata may dominate the marsh platform in nutrient-rich conditions, though the mechanism driving the vegetation shift is unclear. Our study examines belowground nutrient uptake and allocation underlying these patterns. To determine whether D. spicata is a more efficient scavenger of nutrients than S. alterniflora we performed a 15N pulse-chase experiment. Tracer was added to mesocosms growing D. spicata and S. alterniflora in monoculture. After the initial pulse, a subset of pots were sacrificed weekly and partitioned into detailed depth intervals for 15N analysis of several belowground pools: live coarse and fine roots, live rhizomes, dead organic matter, and bulk sediment. Comparisons between D. spicata and S. alterniflora uptake and allocation can explain mechanisms of competitive advantage and predictions of D. spicata dominance. Additionally, we used denitrification enzyme assays (DEA) and greenhouse gas slurries to quantify denitrification rates and potentials. Initial results suggest that the vegetation types support similar N-relevant microbial communities. Th

Regional Contingencies in the Relationship between Aboveground Biomass and Litter in the World’s Grasslands

PubMed Central

O’Halloran, Lydia R.; Borer, Elizabeth T.; Seabloom, Eric W.; MacDougall, Andrew S.; Cleland, Elsa E.; McCulley, Rebecca L.; Hobbie, Sarah; Harpole, W. Stan; DeCrappeo, Nicole M.; Chu, Chengjin; Bakker, Jonathan D.; Davies, Kendi F.; Du, Guozhen; Firn, Jennifer; Hagenah, Nicole; Hofmockel, Kirsten S.; Knops, Johannes M. H.; Li, Wei; Melbourne, Brett A.; Morgan, John W.; Orrock, John L.; Prober, Suzanne M.; Stevens, Carly J.

2013-01-01

Based on regional-scale studies, aboveground production and litter decomposition are thought to positively covary, because they are driven by shared biotic and climatic factors. Until now we have been unable to test whether production and decomposition are generally coupled across climatically dissimilar regions, because we lacked replicated data collected within a single vegetation type across multiple regions, obfuscating the drivers and generality of the association between production and decomposition. Furthermore, our understanding of the relationships between production and decomposition rests heavily on separate meta-analyses of each response, because no studies have simultaneously measured production and the accumulation or decomposition of litter using consistent methods at globally relevant scales. Here, we use a multi-country grassland dataset collected using a standardized protocol to show that live plant biomass (an estimate of aboveground net primary production) and litter disappearance (represented by mass loss of aboveground litter) do not strongly covary. Live biomass and litter disappearance varied at different spatial scales. There was substantial variation in live biomass among continents, sites and plots whereas among continent differences accounted for most of the variation in litter disappearance rates. Although there were strong associations among aboveground biomass, litter disappearance and climatic factors in some regions (e.g. U.S. Great Plains), these relationships were inconsistent within and among the regions represented by this study. These results highlight the importance of replication among regions and continents when characterizing the correlations between ecosystem processes and interpreting their global-scale implications for carbon flux. We must exercise caution in parameterizing litter decomposition and aboveground production in future regional and global carbon models as their relationship is complex. PMID:23405103
Regional contingencies in the relationship between aboveground Bbomass and litter in the world’s grasslands

USGS Publications Warehouse

O’Halloran, Lydia R.; Borer, Elizabeth T.; Seabloom, Eric W.; MacDougall, Andrew S.; Cleland, Elsa E.; McCulley, Rebecca L.; Hobbie, Sarah; Harpole, W. Stan; DeCrappeo, Nicole M.; Chu, Cheng-Jin; Bakker, Jonathan D.; Davies, Kendi F.; Du, Guozhen; Firn, Jennifer; Hagenah, Nicole; Hofmockel, Kirsten S.; Knops, Johannes M.H.; Li, Wei; Melbourne, Brett A.; Morgan, John W.; Orrock, John L.; Prober, Suzanne M.; Stevens, Carly J.

2013-01-01

Based on regional-scale studies, aboveground production and litter decomposition are thought to positively covary, because they are driven by shared biotic and climatic factors. Until now we have been unable to test whether production and decomposition are generally coupled across climatically dissimilar regions, because we lacked replicated data collected within a single vegetation type across multiple regions, obfuscating the drivers and generality of the association between production and decomposition. Furthermore, our understanding of the relationships between production and decomposition rests heavily on separate meta-analyses of each response, because no studies have simultaneously measured production and the accumulation or decomposition of litter using consistent methods at globally relevant scales. Here, we use a multi-country grassland dataset collected using a standardized protocol to show that live plant biomass (an estimate of aboveground net primary production) and litter disappearance (represented by mass loss of aboveground litter) do not strongly covary. Live biomass and litter disappearance varied at different spatial scales. There was substantial variation in live biomass among continents, sites and plots whereas among continent differences accounted for most of the variation in litter disappearance rates. Although there were strong associations among aboveground biomass, litter disappearance and climatic factors in some regions (e.g. U.S. Great Plains), these relationships were inconsistent within and among the regions represented by this study. These results highlight the importance of replication among regions and continents when characterizing the correlations between ecosystem processes and interpreting their global-scale implications for carbon flux. We must exercise caution in parameterizing litter decomposition and aboveground production in future regional and global carbon models as their relationship is complex.
Positive edge effects on forest-interior cryptogams in clear-cuts.

PubMed

Caruso, Alexandro; Rudolphi, Jörgen; Rydin, Håkan

2011-01-01

Biological edge effects are often assessed in high quality focal habitats that are negatively influenced by human-modified low quality matrix habitats. A deeper understanding of the possibilities for positive edge effects in matrix habitats bordering focal habitats (e.g. spillover effects) is, however, essential for enhancing landscape-level resilience to human alterations. We surveyed epixylic (dead wood inhabiting) forest-interior cryptogams (lichens, bryophytes, and fungi) associated with mature old-growth forests in 30 young managed Swedish boreal forest stands bordering a mature forest of high conservation value. In each young stand we registered species occurrences on coarse dead wood in transects 0-50 m from the border between stand types. We quantified the effect of distance from the mature forest on the occurrence of forest-interior species in the young stands, while accounting for local environment and propagule sources. For comparison we also surveyed epixylic open-habitat (associated with open forests) and generalist cryptogams. Species composition of epixylic cryptogams in young stands differed with distance from the mature forest: the frequency of occurrence of forest-interior species decreased with increasing distance whereas it increased for open-habitat species. Generalists were unaffected by distance. Epixylic, boreal forest-interior cryptogams do occur in matrix habitats such as clear-cuts. In addition, they are associated with the matrix edge because of a favourable microclimate closer to the mature forest on southern matrix edges. Retention and creation of dead wood in clear-cuts along the edges to focal habitats is a feasible way to enhance the long-term persistence of epixylic habitat specialists in fragmented landscapes. The proposed management measures should be performed in the whole stand as it matures, since microclimatic edge effects diminish as the matrix habitat matures. We argue that management that aims to increase habitat quality in matrix habitats bordering focal habitats should increase the probability of long-term persistence of habitat specialists.
Positive Edge Effects on Forest-Interior Cryptogams in Clear-Cuts

PubMed Central

Caruso, Alexandro; Rudolphi, Jörgen; Rydin, Håkan

2011-01-01

Biological edge effects are often assessed in high quality focal habitats that are negatively influenced by human-modified low quality matrix habitats. A deeper understanding of the possibilities for positive edge effects in matrix habitats bordering focal habitats (e.g. spillover effects) is, however, essential for enhancing landscape-level resilience to human alterations. We surveyed epixylic (dead wood inhabiting) forest-interior cryptogams (lichens, bryophytes, and fungi) associated with mature old-growth forests in 30 young managed Swedish boreal forest stands bordering a mature forest of high conservation value. In each young stand we registered species occurrences on coarse dead wood in transects 0–50 m from the border between stand types. We quantified the effect of distance from the mature forest on the occurrence of forest-interior species in the young stands, while accounting for local environment and propagule sources. For comparison we also surveyed epixylic open-habitat (associated with open forests) and generalist cryptogams. Species composition of epixylic cryptogams in young stands differed with distance from the mature forest: the frequency of occurrence of forest-interior species decreased with increasing distance whereas it increased for open-habitat species. Generalists were unaffected by distance. Epixylic, boreal forest-interior cryptogams do occur in matrix habitats such as clear-cuts. In addition, they are associated with the matrix edge because of a favourable microclimate closer to the mature forest on southern matrix edges. Retention and creation of dead wood in clear-cuts along the edges to focal habitats is a feasible way to enhance the long-term persistence of epixylic habitat specialists in fragmented landscapes. The proposed management measures should be performed in the whole stand as it matures, since microclimatic edge effects diminish as the matrix habitat matures. We argue that management that aims to increase habitat quality in matrix habitats bordering focal habitats should increase the probability of long-term persistence of habitat specialists. PMID:22114728
Simulated Nitrogen Deposition has Minor Effects on Ecosystem Pools and Fluxes of Energy, Elements, and Biochemicals in a Northern Hardwoods Forest

NASA Astrophysics Data System (ADS)

Talhelm, A. F.; Pregitzer, K. S.; Burton, A. J.; Xia, M.; Zak, D. R.

2017-12-01

The elemental and biochemical composition of plant tissues is an important influence on primary productivity, decomposition, and other aspects of biogeochemistry. Human activity has greatly altered biogeochemical cycles in ecosystems downwind of industrialized regions through atmospheric nitrogen deposition, but most research on these effects focuses on individual elements or steps in biogeochemical cycles. Here, we quantified pools and fluxes of biomass, the four major organic elements (carbon, oxygen, hydrogen, nitrogen), four biochemical fractions (lignin, structural carbohydrates, cell walls, and soluble material), and energy in a mature northern hardwoods forest in Michigan. We sampled the organic and mineral soil, fine and coarse roots, leaf litter, green leaves, and wood for chemical analyses. We then combined these data with previously published and archival information on pools and fluxes within this forest, which included replicated plots receiving either ambient deposition or simulated nitrogen deposition (3 g N m-2 yr-1 for 18 years). Live wood was the largest pool of energy and all elements and biochemical fractions. However, the production of wood, leaf litter, and fine roots represented similar fluxes of carbon, hydrogen, oxygen, cell wall material, and energy, while nitrogen fluxes were dominated by leaf litter and fine roots. Notably, the flux of lignin via fine roots was 70% higher than any other flux. Experimental nitrogen deposition had relatively few significant effects, increasing foliar nitrogen, increasing the concentration of lignin in the soil organic horizon and decreasing pools of all elements and biochemical fractions in the soil organic horizon except nitrogen, lignin, and structural carbohydrates. Overall, we found that differences in tissue chemistry concentrations were important determinants of ecosystem-level pools and fluxes, but that nitrogen deposition had little effect on concentrations, pools, or fluxes in this mature forest. Disclaimer: The views expressed in this poster are those of the authors and do not necessarily represent the views or policies of the U.S. EPA.
Simulating adaptive wood harvest in a changing climate

NASA Astrophysics Data System (ADS)

Yousefpour, Rasoul; Nabel, Julia; Pongratz, Julia

2016-04-01

The world's forest experience substantial carbon exchange fluxes between land and atmosphere. Large carbon sinks occur in response to changes in environmental conditions (such as climate change and increased atmospheric CO2 concentrations), removing about one quarter of current anthropogenic CO2-emissions. Large sinks also occur due to regrowth of forest on areas of agricultural abandonment or forest management. Forest management, on the other hand, also leads to substantial amounts of carbon being eventually released to the atmosphere. Both sinks and sources attributable to forests are therefore dependent on the intensity of management. Forest management in turn depends on the availability of resources, which is influenced by environmental conditions and sustainability of management systems applied. Estimating future carbon fluxes therefore requires accounting for the interaction of environmental conditions, forest growth, and management. However, this interaction is not fully captured by current modeling approaches: Earth system models depict in detail interactions between climate, the carbon cycle, and vegetation growth, but use prescribed information on management. Resource needs and land management, however, are simulated by Integrated Assessment Models that typically only have coarse representations of the influence of environmental changes on vegetation growth and are typically based on the demand for wood driven by regional population growth and energy needs. Here we present a study that provides the link between environmental conditions, forest growth and management. We extend the land component JSBACH of the Max Planck Institute's Earth system model (MPI-ESM) to simulate potential wood harvest in response to altered growth conditions and thus as adaptive to changing climate and CO2 conditions. We apply the altered model to estimate potential wood harvest for future climates (representative concentration pathways, RCPs) for the management scenario of "sustained yields" (SY), i.e. that wood harvest is not allowed to reduce wood carbon stocks below their present-day average state. We find that the potentials for SY range from about 420 to 610 PgC cumulatively until 2100 depending on assumed future climate (RCPs 2.6, 4.5 or 8.5). They are thus substantially higher than the harvest prescribed in the context of the same RCPs for the coupled model intercomparison project (CMIP5), which ranged from about 130 to 210 PgC. The underlying drivers of the higher potentials of SY as compared to the RCP harvest are in all scenarios foremost avoided natural mortality, followed by avoided losses due to fire and windbreak. Further, usage of the increase in forest carbon stocks simulated with time under RCP harvest plays a large role in the first decades of the 21st century. The potential wood harvest that we simulate accounting for environmental changes does not include considerations on biodiversity and other ecosystem services or technical feasibility. However, the substantially higher simulated harvest from SY as compared to that prescribed from the RCPs and the difference found between climate scenarios highlights the need to account for effects of environmental changes on vegetation growth also in socio-economic models and thus the need for a consistent representation of climate-landuse interactions.
Quantifying the time scales over which exogenous and endogenous conditions affect soil respiration

USDA-ARS?s Scientific Manuscript database

Understanding how exogenous and endogenous factors and aboveground-belowground linkages modulate carbon dynamics is difficult because of influences of antecedent conditions. For example, there are variable lags between aboveground assimilation and belowground efflux, and the duration of antecedent p...
40 CFR 279.64 - Used oil storage.

Code of Federal Regulations, 2010 CFR

2010-07-01

... soil, groundwater, or surface water. (d) Secondary containment for existing aboveground tanks. Existing... system to the soil, groundwater, or surface water. (e) Secondary containment for new aboveground tanks... containment system from migrating out of the system to the soil, groundwater, or surface water. (f) Labels. (1...
40 CFR 279.64 - Used oil storage.

Code of Federal Regulations, 2011 CFR

2011-07-01

... soil, groundwater, or surface water. (d) Secondary containment for existing aboveground tanks. Existing... system to the soil, groundwater, or surface water. (e) Secondary containment for new aboveground tanks... containment system from migrating out of the system to the soil, groundwater, or surface water. (f) Labels. (1...
Aboveground growth interactions of paired conifer seedlings in close proximity

Treesearch

Warren D. Devine; Timothy B. Harrington

2011-01-01

Where belowground resources are relatively abundant, naturally established trees sometimes occur in very close proximity to one another. We conducted a two-year study to assess the aboveground interactions between Douglas-fir (Pseudotsuga menziesii), grand fir (Abies grandis) and noble fir (Abies procera)...
Plants as green phones

PubMed Central

Harvey, Jeffrey A; Bezemer, T Martijn; Stuefer, Josef F

2008-01-01

Plants can act as vertical communication channels or ‘green phones’ linking soil-dwelling insects and insects in the aboveground ecosystem. When root-feeding insects attack a plant, the direct defense system of the shoot is activated, leading to an accumulation of phytotoxins in the leaves. The protection of the plant shoot elicited by root damage can impair the survival, growth and development of aboveground insect herbivores, thereby creating plant-based functional links between soil-dwelling insects and insects that develop in the aboveground ecosystem. The interactions between spatially separated insects below- and aboveground are not restricted to root and foliar plant-feeding insects, but can be extended to higher trophic levels such as insect parasitoids. Here we discuss some implications of plants acting as communication channels or ‘green phones’ between root and foliar-feeding insects and their parasitoids, focusing on recent findings that plants attacked by root-feeding insects are significantly less attractive for the parasitoids of foliar-feeding insects. PMID:19513244
Response of NDVI, biomass, and ecosystem gas exchange to long-term warming and fertilization in wet sedge tundra.

PubMed

Boelman, Natalie T; Stieglitz, Marc; Rueth, Heather M; Sommerkorn, Martin; Griffin, Kevin L; Shaver, Gaius R; Gamon, John A

2003-05-01

This study explores the relationship between the normalized difference vegetation index (NDVI), aboveground plant biomass, and ecosystem C fluxes including gross ecosystem production (GEP), ecosystem respiration (ER) and net ecosystem production. We measured NDVI across long-term experimental treatments in wet sedge tundra at the Toolik Lake LTER site, in northern Alaska. Over 13 years, N and P were applied in factorial experiments (N, P and N + P), air temperature was increased using greenhouses with and without N + P fertilizer, and light intensity (photosynthetically active photon flux density) was reduced by 50% using shade cloth. Within each treatment plot, NDVI, aboveground biomass and whole-system CO(2) flux measurements were made at the same sampling points during the peak-growing season of 2001. We found that across all treatments, NDVI is correlated with aboveground biomass ( r(2)=0.84), GEP ( r(2)=0.75) and ER ( r(2)=0.71), providing a basis for linking remotely sensed NDVI to aboveground biomass and ecosystem carbon flux.
Carbon stocks and dynamics at different successional stages in an Afromontane tropical forest

NASA Astrophysics Data System (ADS)

Nyirambangutse, Brigitte; Zibera, Etienne; Uwizeye, Félicien K.; Nsabimana, Donat; Bizuru, Elias; Pleijel, Håkan; Uddling, Johan; Wallin, Göran

2017-03-01

As a result of different types of disturbance, forests are a mixture of stands at different stages of ecological succession. Successional stage is likely to influence forest productivity and carbon storage, linking the degree of forest disturbance to the global carbon cycle and climate. Although tropical montane forests are an important part of tropical forest ecosystems (ca. 8 %, elevation > 1000 m a.s.l.), there are still significant knowledge gaps regarding the carbon dynamics and stocks of these forests, and how these differ between early (ES) and late successional (LS) stages. This study examines the carbon (C) stock, relative growth rate (RGR) and net primary production (NPP) of ES and LS forest stands in an Afromontane tropical rainforest using data from inventories of quantitatively important ecosystem compartments in fifteen 0.5 ha plots in Nyungwe National Park in Rwanda. The total C stock was 35 % larger in LS compared to ES plots due to significantly larger above-ground biomass (AGB; 185 and 76 Mg C ha-1 in LS and ES plots), while the soil and root C stock (down to 45 cm depth in the mineral soil) did not significantly differ between the two successional stages (178 and 204 Mg C ha-1 in LS and ES plots). The main reasons for the difference in AGB were that ES trees had significantly lower stature and wood density compared to LS trees. However, ES and LS stands had similar total NPP (canopy, wood and roots of all plots ˜ 9.4 Mg C ha-1) due to counterbalancing effects of differences in AGB (higher in LS stands) and RGR (higher in ES stands). The AGB in the LS plots was considerably higher than the average value reported for old-growth tropical montane forest of south-east Asia and Central and South America at similar elevations and temperatures, and of the same magnitude as in tropical lowland forest of these regions. The results of this study highlight the importance of accounting for disturbance regimes and differences in wood density and allometry of tree species dominating at different successional stages in an attempt to quantify the C stock and sink strength of tropical montane forests and how they may differ among continents.
Contribution of aboveground plant respiration to carbon cycling in a Bornean tropical rainforet

NASA Astrophysics Data System (ADS)

Katayama, Ayumi; Tanaka, Kenzo; Ichie, Tomoaki; Kume, Tomonori; Matsumoto, Kazuho; Ohashi, Mizue; Kumagai, Tomo'omi

2014-05-01

Bornean tropical rainforests have a different characteristic from Amazonian tropical rainforests, that is, larger aboveground biomass caused by higher stand density of large trees. Larger biomass may cause different carbon cycling and allocation pattern. However, there are fewer studies on carbon allocation and each component in Bornean tropical rainforests, especially for aboveground plant respiration, compared to Amazonian forests. In this study, we measured woody tissue respiration and leaf respiration, and estimated those in ecosystem scale in a Bornean tropical rainforest. Then, we examined carbon allocation using the data of soil respiration and aboveground net primary production obtained from our previous studies. Woody tissue respiration rate was positively correlated with diameter at breast height (dbh) and stem growth rate. Using the relationships and biomass data, we estimated woody tissue respiration in ecosystem scale though methods of scaling resulted in different estimates values (4.52 - 9.33 MgC ha-1 yr-1). Woody tissue respiration based on surface area (8.88 MgC ha-1 yr-1) was larger than those in Amazon because of large aboveground biomass (563.0 Mg ha-1). Leaf respiration rate was positively correlated with height. Using the relationship and leaf area density data at each 5-m height, leaf respiration in ecosystem scale was estimated (9.46 MgC ha-1 yr-1), which was similar to those in Amazon because of comparable LAI (5.8 m2 m-2). Gross primary production estimated from biometric measurements (44.81 MgC ha-1 yr-1) was much higher than those in Amazon, and more carbon was allocated to woody tissue respiration and total belowground carbon flux. Large tree with dbh > 60cm accounted for about half of aboveground biomass and aboveground biomass increment. Soil respiration was also related to position of large trees, resulting in high soil respiration rate in this study site. Photosynthesis ability of top canopy for large trees was high and leaves for the large trees accounted for 30% of total, which can lead high GPP. These results suggest that large trees play considerable role in carbon cycling and make a distinctive carbon allocation in the Bornean tropical rainforest.
Ability of LANDSAT-8 Oli Derived Texture Metrics in Estimating Aboveground Carbon Stocks of Coppice Oak Forests

NASA Astrophysics Data System (ADS)

Safari, A.; Sohrabi, H.

2016-06-01

The role of forests as a reservoir for carbon has prompted the need for timely and reliable estimation of aboveground carbon stocks. Since measurement of aboveground carbon stocks of forests is a destructive, costly and time-consuming activity, aerial and satellite remote sensing techniques have gained many attentions in this field. Despite the fact that using aerial data for predicting aboveground carbon stocks has been proved as a highly accurate method, there are challenges related to high acquisition costs, small area coverage, and limited availability of these data. These challenges are more critical for non-commercial forests located in low-income countries. Landsat program provides repetitive acquisition of high-resolution multispectral data, which are freely available. The aim of this study was to assess the potential of multispectral Landsat 8 Operational Land Imager (OLI) derived texture metrics in quantifying aboveground carbon stocks of coppice Oak forests in Zagros Mountains, Iran. We used four different window sizes (3×3, 5×5, 7×7, and 9×9), and four different offsets ([0,1], [1,1], [1,0], and [1,-1]) to derive nine texture metrics (angular second moment, contrast, correlation, dissimilar, entropy, homogeneity, inverse difference, mean, and variance) from four bands (blue, green, red, and infrared). Totally, 124 sample plots in two different forests were measured and carbon was calculated using species-specific allometric models. Stepwise regression analysis was applied to estimate biomass from derived metrics. Results showed that, in general, larger size of window for deriving texture metrics resulted models with better fitting parameters. In addition, the correlation of the spectral bands for deriving texture metrics in regression models was ranked as b4>b3>b2>b5. The best offset was [1,-1]. Amongst the different metrics, mean and entropy were entered in most of the regression models. Overall, different models based on derived texture metrics were able to explain about half of the variation in aboveground carbon stocks. These results demonstrated that Landsat 8 derived texture metrics can be applied for mapping aboveground carbon stocks of coppice Oak Forests in large areas.
Forecasting annual aboveground net primary production in the intermountain west

USDA-ARS?s Scientific Manuscript database

For many land manager’s annual aboveground net primary production, or plant growth, is a key factor affecting business success, profitability and each land manager's ability to successfully meet land management objectives. The strategy often utilized for forecasting plant growth is to assume every y...
Aboveground and belowground net primary production

Treesearch

Hal O. Liechty; Mark H. Eisenbies

2000-01-01

The relationship among net primary productivity (NPP), hydroperiod, and fertility in forested wetlands is poorly understood (Burke and others 1999), particularly with respect to belowground NPP (Megonigal and others 1997). Although some researchers have studied aboveground and belowground primary production in depressional, forested wetland systems, e.g., Day and...
WEAPONS STORAGE AREA. FROM RIGHT TO LEFT, ABOVEGROUND STORAGE MAGAZINE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

WEAPONS STORAGE AREA. FROM RIGHT TO LEFT, ABOVEGROUND STORAGE MAGAZINE (BUILDING 3568), SPARES INERT STORAGE BUILDING (BUILDING 3570), MISSILE ASSEMBLY SHOP (BUILDING 3578) AND SEGREGATED MAGAZINE STORAGE BUILDING (BUILDING 3572). VIEW TO NORTHWEST - Plattsburgh Air Force Base, U.S. Route 9, Plattsburgh, Clinton County, NY
Trade-offs in plant responses to herbivory influence trophic routes of production in a freshwater wetland.

PubMed

Cherry, Julia A; Gough, Laura

2009-09-01

Responses of aquatic macrophytes to leaf herbivory may differ from those documented for terrestrial plants, in part, because the potential to maximize growth following herbivory may be limited by the stress of being rooted in flooded, anaerobic sediments. Herbivory on aquatic macrophytes may have ecosystem consequences by altering the allocation of nutrients and production of biomass within individual plants and changing the quality and quantity of aboveground biomass available to consumers or decomposers. To test the effects of leaf herbivory on plant growth and production, herbivory of a dominant macrophyte, Nymphaea odorata, by chrysomelid beetles and crambid moths was controlled during a 2-year field experiment. Plants exposed to herbivory maintained, or tended to increase, biomass and aboveground net primary production relative to controls, which resulted in 1.5 times more aboveground primary production entering the detrital pathway of the wetland. In a complementary greenhouse experiment, the effects of simulated leaf herbivory on total plant responses, including biomass and nutrient allocation, were investigated. Plants in the greenhouse responded to moderate herbivory by maintaining aboveground biomass relative to controls, but this response occurred at the expense of belowground growth. Results of these studies suggest that N. odorata may tolerate moderate levels of herbivory by reallocating biomass and resources aboveground, which in turn influences the quantity, quality and fate of organic matter available to herbivores and decomposers.
Refuse dumps from leaf-cutting ant nests reduce the intensity of above-ground competition among neighboring plants in a Patagonian steppe

NASA Astrophysics Data System (ADS)

Farji-Brener, Alejandro G.; Lescano, María Natalia

2017-11-01

In arid environments, the high availability of sunlight due to the scarcity of trees suggests that plant competition take place mainly belowground for water and nutrients. However, the occurrence of soil disturbances that increase nutrient availability and thereby promote plant growth may enhance shoot competition between neighboring plants. We conducted a greenhouse experiment to evaluate the influence of the enriched soil patches generated by the leaf-cutting ant, Acromyrmex lobicornis, on the performance of the alien forb Carduus thoermeri (Asteraceae) under different intraspecific competition scenarios. Our results showed that substrate type and competition scenario affected mainly aboveground plant growth. As expected, plants growing without neighbors and in nutrient-rich ant refuse dumps showed more aboveground biomass than plants growing with neighbors and in nutrient-poor steppe soils. However, aboveground competition was more intense in nutrient-poor substrates: plants under shoot and full competition growing in the nutrient-rich ant refuse dumps showed higher biomass than those growing on steppe soils. Belowground biomass was similar among focal plants growing under different substrate type. Our results support the traditional view that increments in resource availability reduce competition intensity. Moreover, the fact that seedlings in this sunny habitat mainly compete aboveground illustrates how limiting factors may be scale-dependent and change in importance as plants grow.

Estimating aboveground live understory vegetation carbon in the United States

NASA Astrophysics Data System (ADS)

Johnson, Kristofer D.; Domke, Grant M.; Russell, Matthew B.; Walters, Brian; Hom, John; Peduzzi, Alicia; Birdsey, Richard; Dolan, Katelyn; Huang, Wenli

2017-12-01

Despite the key role that understory vegetation plays in ecosystems and the terrestrial carbon cycle, it is often overlooked and has few quantitative measurements, especially at national scales. To understand the contribution of understory carbon to the United States (US) carbon budget, we developed an approach that relies on field measurements of understory vegetation cover and height on US Department of Agriculture Forest Service, Forest Inventory and Analysis (FIA) subplots. Allometric models were developed to estimate aboveground understory carbon. A spatial model based on stand characteristics and remotely sensed data was also applied to estimate understory carbon on all FIA plots. We found that most understory carbon was comprised of woody shrub species (64%), followed by nonwoody forbs and graminoid species (35%) and seedlings (1%). The largest estimates were found in temperate or warm humid locations such as the Pacific Northwest and southeastern US, thus following the same broad trend as aboveground tree biomass. The average understory aboveground carbon density was estimated to be 0.977 Mg ha-1, for a total estimate of 272 Tg carbon across all managed forest land in the US (approximately 2% of the total aboveground live tree carbon pool). This estimate is more than twice as low as previous FIA modeled estimates that did not rely on understory measurements, suggesting that this pool may currently be overestimated in US National Greenhouse Gas reporting.
Aboveground net primary production responses to water availability in the Chihuhuan Desert: importance of legacy effects

USDA-ARS?s Scientific Manuscript database

In arid ecosystems, current year precipitation explains a small proportion of annual aboveground net primary production (ANPP). Precipitation that occurred in previous years may be responsible for the observed difference between actual and expected ANPP, a concept that we called legacy. Thus, previo...
Long-term above-ground biomass production in a red oak-pecan agroforestry system

USDA-ARS?s Scientific Manuscript database

Agroforestry systems have widely been recognized for their potential to foster long-term carbon sequestration in woody perennials. This study aims to determine the above-ground biomass in a 16-year-old red oak (Quercus rubra) - pecan (Carya illinoinensis) silvopastoral planting (141 and 53 trees ha-...
Family Differences in Aboveground Biomass Allocation in Loblolly Pine

Treesearch

Scott D. Roberts

2002-01-01

The proportion of tree growth allocated to stemwood is an important economic component of growth efficiency. Differences in growth efficiency between species, or between families within species, may therefore be related to how growth is proportionally allocated between the stem and other aboveground biomass components. This study examines genetically related...
Radioactive and Stable Cesium Distributions in Fukushima Forests

NASA Astrophysics Data System (ADS)

Ioshchenko, V.; Kivva, S.; Konoplev, A.; Nanba, K.; Onda, Y.; Takase, T.; Zheleznyak, M.

2015-12-01

Fukushima Dai-ichi NPP accident has resulted in release into the environment of large amounts of 134Cs and 137Cs and in radioactive contamination of terrestrial and aquatic ecosystems. In Fukushima prefecture up to 2/3 of the most contaminated territory is covered with forests, and understanding of its further fate in the forest ecosystems is essential for elaboration of the long-term forestry strategy. At the early stage, radiocesium was intercepted by the trees' canopies. Numerous studies reported redistribution of the initial fallout in Fukushima forests in the followed period due to litterfall and leaching of radiocesium from the foliage with precipitations. By now these processes have transported the major part of deposited radiocesium to litter and soil compartments. Future levels of radiocesium activities in the aboveground biomass will depend on relative efficiencies of the radiocesium root uptake and its return to the soil surface with litterfall and precipitations. Radiocesium soil-to-plant transfer factors for typical tree species, soil types and landscape conditions of Fukushima prefecture have not been studied well; moreover, they may change in time with approaching to the equilibrium between radioactive and stable cesium isotopes in the ecosystem. The present paper reports the results of several ongoing projects carried out by Institute of Environmental Radioactivity of Fukushima University at the experimental sites in Fukushima prefecture. For typical Japanese cedar (Cryptomeria japonica) forest, we determined distributions of radiocesium in the ecosystem and in the aboveground biomass compartments by the end of 2014; available results for 2015 are presented, too, as well as the results of test application of D-shuttle dosimeters for characterization of seasonal variations of radiocesium activity in wood. Based on the radiocesium activities in biomass we derived the upper estimates of its incorporation and root uptake fluxes, 0.7% and 3% of the total inventory in the ecosystem. Measurements of stable cesium concentrations in the biomass compartments enabled obtaining the more precise estimates. Return fluxes of both radioactive and stable cesium also were quantified, which forms the basis for modelling of the long-term redistribution of radiocesium in the studied ecosystem.
Developing Cost-Effective Field Assessments of Carbon Stocks in Human-Modified Tropical Forests.

PubMed

Berenguer, Erika; Gardner, Toby A; Ferreira, Joice; Aragão, Luiz E O C; Camargo, Plínio B; Cerri, Carlos E; Durigan, Mariana; Oliveira Junior, Raimundo C; Vieira, Ima C G; Barlow, Jos

2015-01-01

Across the tropics, there is a growing financial investment in activities that aim to reduce emissions from deforestation and forest degradation, such as REDD+. However, most tropical countries lack on-the-ground capacity to conduct reliable and replicable assessments of forest carbon stocks, undermining their ability to secure long-term carbon finance for forest conservation programs. Clear guidance on how to reduce the monetary and time costs of field assessments of forest carbon can help tropical countries to overcome this capacity gap. Here we provide such guidance for cost-effective one-off field assessments of forest carbon stocks. We sampled a total of eight components from four different carbon pools (i.e. aboveground, dead wood, litter and soil) in 224 study plots distributed across two regions of eastern Amazon. For each component we estimated survey costs, contribution to total forest carbon stocks and sensitivity to disturbance. Sampling costs varied thirty-one-fold between the most expensive component, soil, and the least, leaf litter. Large live stems (≥10 cm DBH), which represented only 15% of the overall sampling costs, was by far the most important component to be assessed, as it stores the largest amount of carbon and is highly sensitive to disturbance. If large stems are not taxonomically identified, costs can be reduced by a further 51%, while incurring an error in aboveground carbon estimates of only 5% in primary forests, but 31% in secondary forests. For rapid assessments, necessary to help prioritize locations for carbon- conservation activities, sampling of stems ≥20cm DBH without taxonomic identification can predict with confidence (R2 = 0.85) whether an area is relatively carbon-rich or carbon-poor-an approach that is 74% cheaper than sampling and identifying all the stems ≥10cm DBH. We use these results to evaluate the reliability of forest carbon stock estimates provided by the IPCC and FAO when applied to human-modified forests, and to highlight areas where cost savings in carbon stock assessments could be most easily made.
A synthesis of terrestrial mercury in the western United States: Spatial distribution defined by land cover and plant productivity.

PubMed

Obrist, Daniel; Pearson, Christopher; Webster, Jackson; Kane, Tyler; Lin, Che-Jen; Aiken, George R; Alpers, Charles N

2016-10-15

A synthesis of published vegetation mercury (Hg) data across 11 contiguous states in the western United States showed that aboveground biomass concentrations followed the order: leaves (26μgkg(-1))~branches (26μgkg(-1))>bark (16μgkg(-1))>bole wood (1μgkg(-1)). No spatial trends of Hg in aboveground biomass distribution were detected, which likely is due to very sparse data coverage and different sampling protocols. Vegetation data are largely lacking for important functional vegetation types such as shrubs, herbaceous species, and grasses. Soil concentrations collected from the published literature were high in the western United States, with 12% of observations exceeding 100μgkg(-1), reflecting a bias toward investigations in Hg-enriched sites. In contrast, soil Hg concentrations from a randomly distributed data set (1911 sampling points; Smith et al., 2013a) averaged 24μgkg(-1) (A-horizon) and 22μgkg(-1) (C-horizon), and only 2.6% of data exceeded 100μgkg(-1). Soil Hg concentrations significantly differed among land covers, following the order: forested upland>planted/cultivated>herbaceous upland/shrubland>barren soils. Concentrations in forests were on average 2.5 times higher than in barren locations. Principal component analyses showed that soil Hg concentrations were not or weakly related to modeled dry and wet Hg deposition and proximity to mining, geothermal areas, and coal-fired power plants. Soil Hg distribution also was not closely related to other trace metals, but strongly associated with organic carbon, precipitation, canopy greenness, and foliar Hg pools of overlying vegetation. These patterns indicate that soil Hg concentrations are related to atmospheric deposition and reflect an overwhelming influence of plant productivity - driven by water availability - with productive landscapes showing high soil Hg accumulation and unproductive barren soils and shrublands showing low soil Hg values. Large expanses of low-productivity, arid ecosystems across the western U.S. result in some of the lowest soil Hg concentrations observed worldwide. Copyright © 2015 Elsevier B.V. All rights reserved.
Developing Cost-Effective Field Assessments of Carbon Stocks in Human-Modified Tropical Forests

PubMed Central

Berenguer, Erika; Gardner, Toby A.; Ferreira, Joice; Aragão, Luiz E. O. C.; Camargo, Plínio B.; Cerri, Carlos E.; Durigan, Mariana; Oliveira Junior, Raimundo C.; Vieira, Ima C. G.; Barlow, Jos

2015-01-01

Across the tropics, there is a growing financial investment in activities that aim to reduce emissions from deforestation and forest degradation, such as REDD+. However, most tropical countries lack on-the-ground capacity to conduct reliable and replicable assessments of forest carbon stocks, undermining their ability to secure long-term carbon finance for forest conservation programs. Clear guidance on how to reduce the monetary and time costs of field assessments of forest carbon can help tropical countries to overcome this capacity gap. Here we provide such guidance for cost-effective one-off field assessments of forest carbon stocks. We sampled a total of eight components from four different carbon pools (i.e. aboveground, dead wood, litter and soil) in 224 study plots distributed across two regions of eastern Amazon. For each component we estimated survey costs, contribution to total forest carbon stocks and sensitivity to disturbance. Sampling costs varied thirty-one-fold between the most expensive component, soil, and the least, leaf litter. Large live stems (≥10 cm DBH), which represented only 15% of the overall sampling costs, was by far the most important component to be assessed, as it stores the largest amount of carbon and is highly sensitive to disturbance. If large stems are not taxonomically identified, costs can be reduced by a further 51%, while incurring an error in aboveground carbon estimates of only 5% in primary forests, but 31% in secondary forests. For rapid assessments, necessary to help prioritize locations for carbon- conservation activities, sampling of stems ≥20cm DBH without taxonomic identification can predict with confidence (R2 = 0.85) whether an area is relatively carbon-rich or carbon-poor—an approach that is 74% cheaper than sampling and identifying all the stems ≥10cm DBH. We use these results to evaluate the reliability of forest carbon stock estimates provided by the IPCC and FAO when applied to human-modified forests, and to highlight areas where cost savings in carbon stock assessments could be most easily made. PMID:26308074
Comparison of Growth Efficiency of Mature Longleaf and Slash Pine Trees

Treesearch

Steven B. Jack; Mary Carol P. Sheffield; Daniel J. McConville

2002-01-01

Variation in aboveground biomass partitioning (between the stem, branches, and foliage) of mature trees is a key determinant of growth potential. Investment of photosynthate in crown components generally results in greater overall biomass production of longer duration. The increased production of crown components may be an investment in longterm aboveground production...
Estimating aboveground tree biomass on forest land in the Pacific Northwest: a comparison of approaches

Treesearch

Xiaoping Zhou; Miles A. Hemstrom

2009-01-01

Live tree biomass estimates are essential for carbon accounting, bioenergy feasibility studies, and other analyses. Several models are currently used for estimating tree biomass. Each of these incorporates different calculation methods that may significantly impact the estimates of total aboveground tree biomass, merchantable biomass, and carbon pools. Consequently,...
Biomass distribution and productivity of Pinus edulis-Juniperus monosperma woodlands of north-central Arizona

Treesearch

Charles C. Grier; Katherine J. Elliott; Deborah G. McCullough

1992-01-01

Above-ground biomass distribution, leaf area, above-ground net primary productivity and foliage characteristics were determined for 90- and 350-year-old Pinus edulis-Juniperus monosperma ecosystems on the Colorado Plateau of northern Arizona. These ecosystems have low biomass, leaf area and primary productivity compared with forests in wetter...
49 CFR 195.307 - Pressure testing aboveground breakout tanks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... placed in service after October 2, 2000, pneumatic testing must be in accordance with section 5.3 of API Specification 12 F (incorporated by reference, see § 195.3). (b) For aboveground breakout tanks built to API Standard 620 and first placed in service after October 2, 2000, hydrostatic and pneumatic testing must be...
Simulating vegetation controls on hurricane-induced shallow landslides with a distributed ecohydrological model

Treesearch

Taehee Hwang; Lawrence E. Band; T. C. Hales; Chelcy F. Miniat; James M. Vose; Paul V. Bolstad; Brian Miles; Katie Price

2015-01-01

The spatial distribution of shallow landslides in steep forested mountains is strongly controlled by aboveground and belowground biomass, including the distribution of root cohesion. While remote sensing of aboveground canopy properties is relatively advanced, estimating the spatial distribution of root cohesion at the forest landscape scale remains challenging. We...
Effects of precipitation changes on aboveground net primary production and soil respiration in a switchgrass field

USDA-ARS?s Scientific Manuscript database

This study attempted to test whether switchgrass aboveground net primary production (ANPP) responds to precipitation (PPT) changes in a double asymmetry pattern as framed by Knapp et al. (2016), and whether it is held true for other ecosystem processes such as soil respiration (SR). Data were colle...
Aboveground vertebrate and invertebrate herbivore impacts on net N mineralization in subalpine grasslands

Treesearch

Anita C. Risch; Martin Schutz; Martijn L. Vandegehuchte; Wim H. van der Putten; Henk Duyts; Ursina Raschein; Dariusz J. Gwiazdowicz; Matt D. Busse; Deborah S. Page-Dumroese; Stephan Zimmerman

2015-01-01

Aboveground herbivores have strong effects on grassland nitrogen (N) cycling. They can accelerate or slow down soil net N mineralization depending on ecosystem productivity and grazing intensity. Yet, most studies only consider either ungulates or invertebrate herbivores, but not the combined effect of several functionally different vertebrate and invertebrate...
Does the aboveground herbivore assemblage influence soil bacterial community composition and richness in subalpine grasslands?

Treesearch

Melanie Hodel; Martin Schütz; Martijn L. Vandegehuchte; Beat Frey; Matthias Albrecht; Matt D. Busse; Anita C. Risch

2014-01-01

Grassland ecosystems support large communities of aboveground herbivores that can alter ecosystem processes. Thus, grazing by herbivores can directly and indirectly affect belowground properties such as the microbial community structure and diversity. Even though multiple species of functionally different herbivores coexist in grassland ecosystems, most studies have...
Aboveground biomass in Tibetan grasslands

Treesearch

Y.H. Yang; J.Y. Fang; Y.D. Pan; C.J. Ji

2009-01-01

This study investigated spatial patterns and environmental controls of aboveground biomass (AGB) in alpine grasslands on the Tibetan Plateau by integrating AGB data collected from 135 sites during 2001-2004 and concurrent enhanced vegetation index derived from MODIS data sets. The AGB was estimated at 68.8 gm-2, with a larger value (90.8 gm
Predicting Biomass of Understory Stems in the Miississipi and Alabama Coastal Plains

Treesearch

B.L. Franchi; I.W. Savelle; W.F. Watson; B.J. Stokes

1984-01-01

Understory forest biomass is becoming an important source of industrial fuelwood. Up to 40 tons per acre of above-ground biomass may be present in the understory of Southern pine stands. The above-ground portion is the only portion of the tree that can be harvested economically for fuel.
Establishment and early growth of Populus hybrids irrigated with landfill leachate

Treesearch

Ronald S., Jr. Zalesny; Adam H. Wiese; Edmund O. Bauer; Jill A. Zalesny

2007-01-01

Hybrid poplar genotypes exhibit great potential for tree establishment and growth when irrigated with municipal solid waste landfill leachate. We evaluated the potential for establishment on leachate-irrigated soils by testing: 1) aboveground growth of hybrid poplar during repeated irrigation with landfill leachate and 2) aboveground and belowground biomass after 70 d...
Climatic controls of aboveground net primary production in semi-arid grasslands along a latitudinal gradient portend low sensitivity to warming

USDA-ARS?s Scientific Manuscript database

Although climate models forecast warmer temperatures with a high degree of certainty, precipitation is the primary driver of aboveground net primary productivity (ANPP) in most grasslands. In contrast, variations in temperature seldom are related to patterns of ANPP. Thus forecasting responses to wa...

Biomass Increases Go under Cover: Woody Vegetation Dynamics in South African Rangelands

PubMed Central

Mograbi, Penelope J.; Knapp, David E.; Martin, Roberta E.; Main, Russell

2015-01-01

Woody biomass dynamics are an expression of ecosystem function, yet biomass estimates do not provide information on the spatial distribution of woody vegetation within the vertical vegetation subcanopy. We demonstrate the ability of airborne light detection and ranging (LiDAR) to measure aboveground biomass and subcanopy structure, as an explanatory tool to unravel vegetation dynamics in structurally heterogeneous landscapes. We sampled three communal rangelands in Bushbuckridge, South Africa, utilised by rural communities for fuelwood harvesting. Woody biomass estimates ranged between 9 Mg ha-1 on gabbro geology sites to 27 Mg ha-1 on granitic geology sites. Despite predictions of woodland depletion due to unsustainable fuelwood extraction in previous studies, biomass in all the communal rangelands increased between 2008 and 2012. Annual biomass productivity estimates (10–14% p.a.) were higher than previous estimates of 4% and likely a significant contributor to the previous underestimations of modelled biomass supply. We show that biomass increases are attributable to growth of vegetation <5 m in height, and that, in the high wood extraction rangeland, 79% of the changes in the vertical vegetation subcanopy are gains in the 1-3m height class. The higher the wood extraction pressure on the rangelands, the greater the biomass increases in the low height classes within the subcanopy, likely a strong resprouting response to intensive harvesting. Yet, fuelwood shortages are still occurring, as evidenced by the losses in the tall tree height class in the high extraction rangeland. Loss of large trees and gain in subcanopy shrubs could result in a structurally simple landscape with reduced functional capacity. This research demonstrates that intensive harvesting can, paradoxically, increase biomass and this has implications for the sustainability of ecosystem service provision. The structural implications of biomass increases in communal rangelands could be misinterpreted as woodland recovery in the absence of three-dimensional, subcanopy information. PMID:25969985
Functional traits determine tree growth and ecosystem productivity of a tropical montane forest: Insights from a long-term nutrient manipulation experiment.

PubMed

Báez, Selene; Homeier, Jürgen

2018-01-01

Trait-response effects are critical to forecast community structure and biomass production in highly diverse tropical forests. Ecological theory and few observation studies indicate that trees with acquisitive functional traits would respond more strongly to higher resource availability than those with conservative traits. We assessed how long-term tree growth in experimental nutrient addition plots (N, P, and N + P) varied as a function of morphological traits, tree size, and species identity. We also evaluated how trait-based responses affected stand scale biomass production considering the community structure. We found that tree growth depended on interactions between functional traits and the type or combination of nutrients added. Common species with acquisitive functional traits responded more strongly to nutrient addition, mainly to N + P. Phosphorous enhanced the growth rates of species with acquisitive and conservative traits, had mostly positive effects on common species and neutral or negative effects in rare species. Moreover, trees receiving N + P grew faster irrespective of their initial size relative to trees in control or to trees in other treatment plots. Finally, species responses were highly idiosyncratic suggesting that community processes including competition and niche dimensionality may be altered under increased resource availability. We found no statistically significant effects of nutrient additions on aboveground biomass productivity because acquisitive species had a limited potential to increase their biomass, possibly due to their generally lower wood density. In contrast, P addition increased the growth rates of species characterized by more conservative resource strategies (with higher wood density) that were poorly represented in the plant community. We provide the first long-term experimental evidence that trait-based responses, community structure, and community processes modulate the effects of increased nutrient availability on biomass productivity in a tropical forest. © 2017 John Wiley & Sons Ltd.
Forest Ecosystem respiration estimated from eddy covariance and chamber measurements under high turbulence and substantial tree mortality from bark beetles

USGS Publications Warehouse

Speckman, Heather N.; Frank, John M.; Bradford, John B.; Miles, Brianna L.; Massman, William J.; Parton, William J.; Ryan, Michael G.

2015-01-01

Eddy covariance nighttime fluxes are uncertain due to potential measurement biases. Many studies report eddy covariance nighttime flux lower than flux from extrapolated chamber measurements, despite corrections for low turbulence. We compared eddy covariance and chamber estimates of ecosystem respiration at the GLEES Ameriflux site over seven growing seasons under high turbulence (summer night mean friction velocity (u*) = 0.7 m s−1), during which bark beetles killed or infested 85% of the aboveground respiring biomass. Chamber-based estimates of ecosystem respiration during the growth season, developed from foliage, wood and soil CO2 efflux measurements, declined 35% after 85% of the forest basal area had been killed or impaired by bark beetles (from 7.1 ±0.22 μmol m−2 s−1 in 2005 to 4.6 ±0.16 μmol m−2 s−1 in 2011). Soil efflux remained at ~3.3 μmol m−2 s−1 throughout the mortality, while the loss of live wood and foliage and their respiration drove the decline of the chamber estimate. Eddy covariance estimates of fluxes at night remained constant over the same period, ~3.0 μmol m−2 s−1 for both 2005 (intact forest) and 2011 (85% basal area killed or impaired). Eddy covariance fluxes were lower than chamber estimates of ecosystem respiration (60% lower in 2005, and 32% in 2011), but the mean night estimates from the two techniques were correlated within a year (r2 from 0.18-0.60). The difference between the two techniques was not the result of inadequate turbulence, because the results were robust to a u* filter of > 0.7 m s−1. The decline in the average seasonal difference between the two techniques was strongly correlated with overstory leaf area (r2=0.92). The discrepancy between methods of respiration estimation should be resolved to have confidence in ecosystem carbon flux estimates.
Is Matang Mangrove Forest in Malaysia Sustainably Rejuvenating after More than a Century of Conservation and Harvesting Management?

PubMed Central

Van der Stocken, Tom; Quispe Zuniga, Melissa; Mohd-Lokman, Husain; Sulong, Ibrahim

2014-01-01

Matang Mangrove Forest Reserve (MMFR) in Peninsular Malaysia is under systematic management since 1902 and still considered as the best managed mangrove forest in the world. The present study on silvimetrics assessed the ongoing MMFR forest management, which includes a first thinning after 15 years, a second thinning after 20 years and clear-felling of 30-year old forest blocks, for its efficiency and productivity in comparison to natural mangroves. The estimated tree structural parameters (e.g. density, frequency) from three different-aged mangrove blocks of fifteen (MF15), twenty (MF20), and thirty (MF30) years old indicated that Bruguiera and Excoecaria spp. did not constitute a significant proportion of the vegetation (<5%), and hence the results focused majorly on Rhizophora apiculata. The density of R. apiculata at MF15, MF20 and MF30 was 4,331, 2,753 and 1,767 stems ha−1, respectively. In relation to ongoing practices of the artificial thinnings at MMFR, the present study suggests that the first thinning could be made earlier to limit the loss of exploitable wood due to natural thinning. In fact, the initial density at MF15 was expected to drop down from 6,726 to 1,858 trees ha−1 before the first thinning. Therefore the trees likely to qualify for natural thinning, though having a smaller stem diameter, should be exploited for domestic/commercial purposes at an earlier stage. The clear-felling block (MF30) with a maximum stem diameter of 30 cm was estimated to yield 372 t ha−1 of the above-ground biomass and suggests that the mangrove management based on a 30-year rotation is appropriate for the MMFR. Since Matang is the only iconic site that practicing sustainable wood production, it could be an exemplary to other mangrove locations for their improved management. PMID:25144689
Characteristics of train noise in above-ground and underground stations with side and island platforms

NASA Astrophysics Data System (ADS)

Shimokura, Ryota; Soeta, Yoshiharu

2011-04-01

Railway stations can be principally classified by their locations, i.e., above-ground or underground stations, and by their platform styles, i.e., side or island platforms. However, the effect of the architectural elements on the train noise in stations is not well understood. The aim of the present study is to determine the different acoustical characteristics of the train noise for each station style. The train noise was evaluated by (1) the A-weighted equivalent continuous sound pressure level ( LAeq), (2) the amplitude of the maximum peak of the interaural cross-correlation function (IACC), (3) the delay time ( τ1) and amplitude ( ϕ1) of the first maximum peak of the autocorrelation function. The IACC, τ1 and ϕ1 are related to the subjective diffuseness, pitch and pitch strength, respectively. Regarding the locations, the LAeq in the underground stations was 6.4 dB higher than that in the above-ground stations, and the pitch in the underground stations was higher and stronger. Regarding the platform styles, the LAeq on the side platforms was 3.3 dB higher than on the island platforms of the above-ground stations. For the underground stations, the LAeq on the island platforms was 3.3 dB higher than that on the side platforms when a train entered the station. The IACC on the island platforms of the above-ground stations was higher than that in the other stations.
Elevated CO2 enrichment induces a differential biomass response in a mixed species temperate forest plantation.

PubMed

Smith, Andrew R; Lukac, Martin; Hood, Robin; Healey, John R; Miglietta, Franco; Godbold, Douglas L

2013-04-01

In a free-air carbon dioxide (CO(2)) enrichment study (BangorFACE), Alnus glutinosa, Betula pendula and Fagus sylvatica were planted in areas of one-, two- and three-species mixtures (n = 4). The trees were exposed to ambient or elevated CO(2) (580 μmol mol(-1)) for 4 yr, and aboveground growth characteristics were measured. In monoculture, the mean effect of CO(2) enrichment on aboveground woody biomass was + 29, + 22 and + 16% for A. glutinosa, F. sylvatica and B. pendula, respectively. When the same species were grown in polyculture, the response to CO(2) switched to + 10, + 7 and 0% for A. glutinosa, B. pendula and F. sylvatica, respectively. In ambient atmosphere, our species grown in polyculture increased aboveground woody biomass from 12.9 ± 1.4 to 18.9 ± 1.0 kg m(-2), whereas, in an elevated CO(2) atmosphere, aboveground woody biomass increased from 15.2 ± 0.6 to 20.2 ± 0.6 kg m(-2). The overyielding effect of polyculture was smaller (+ 7%) in elevated CO(2) than in an ambient atmosphere (+ 18%). Our results show that the aboveground response to elevated CO(2) is affected significantly by intra- and interspecific competition, and that the elevated CO(2) response may be reduced in forest communities comprising tree species with contrasting functional traits. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.
[Aboveground architecture and biomass distribution of Quercus variabilis].

PubMed

Yu, Bi-yun; Zhang, Wen-hui; Hu, Xiao-jing; Shen, Jia-peng; Zhen, Xue-yuan; Yang, Xiao-zhou

2015-08-01

The aboveground architecture, biomass and its allocation, and the relationship between architecture and biomass of Quercus variabilis of different diameter classes in Shangluo, south slope of Qinling Mountains were researched. The results showed that differences existed in the aboveground architecture and biomass allocation of Q. variabilis of different diameter classes. With the increase of diameter class, tree height, DBH, and crown width increased gradually. The average decline rate of each diameter class increased firstly then decreased. Q. variabilis overall bifurcation ratio and stepwise bifurcation ratio increased then declined. The specific leaf areas of Q. variabilis of all different diameter classes at vertical direction were 0.02-0.03, and the larger values of leaf mass ratio, LAI and leaf area ratio at vertical direction in diameter level I , II, III appeared in the middle and upper trunk, while in diameter level IV, V, VI, they appeared in the central trunk, with the increase of diameter class, there appeared two peaks in vertical direction, which located in the lower and upper trunk. The trunk biomass accounted for 71.8%-88.4% of Q. variabilis aboveground biomass, while the branch biomass accounted for 5.8%-19.6%, and the leaf biomass accounted for 4.2%-8.6%. With the increase of diameter class, stem biomass proportion of Q. variabilis decreased firstly then increased, while the branch and leaf biomass proportion showed a trend that increased at first then decreased, and then increased again. The aboveground biomass of Q. variabilis was significantly positively correlated to tree height, DBH, crown width and stepwise bifurcation ratio (R2:1), and positively related to the overall bifurcation ratio and stepwise bifurcation ratio (R3:2), but there was no significant correlation. Trunk biomass and total biomass aboveground were negatively related to the trunk decline rate, while branch biomass and leaf biomass were positively related to trunk decline rate, but their correlations were all not significant.
Development of a size reduction equation for woody biomass: The influence of branch wood properties on Rittinger's constant

DOE PAGES

Naimi, Ladan J.; Sokhansanj, Shahabaddine; Bi, Xiaotao; ...

2015-11-25

Size reduction is an essential but energy-intensive process for preparing biomass for conversion processes. Three well-known scaling equations (Bond, Kick, and Rittinger) are used to estimate energy input for grinding minerals and food particles. Previous studies have shown that the Rittinger equation has the best fit to predict energy input for grinding cellulosic biomass. In the Rittinger equation, Rittinger's constant (k R) is independent of the size of ground particles, yet we noted large variations in k R among similar particle size ranges. In this research, the dependence of k R on the physical structure and chemical composition of amore » number of woody materials was explored. Branches from two softwood species (Douglas fir and pine) and two hardwood species (aspen and poplar) were ground in a laboratory knife mill. The recorded data included power input, mass flow rate, and particle size before and after grinding. Nine material properties were determined: particle density, solid density (pycnometer and x-ray diffraction methods), microfibril angle, fiber coarseness, fiber length, and composition (lignin and cellulose glucan contents). The correlation matrix among the nine properties revealed high degrees of interdependence between properties. The k R value had the largest positive correlation (+0.60) with particle porosity across the species tested. As a result, particle density was strongly correlated with lignin content (0.85), microfibril angle (0.71), fiber length (0.87), and fiber coarseness (0.78). An empirical model relating k R to particle density was developed.« less
Development of a size reduction equation for woody biomass: The influence of branch wood properties on Rittinger's constant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naimi, Ladan J.; Sokhansanj, Shahabaddine; Bi, Xiaotao

Size reduction is an essential but energy-intensive process for preparing biomass for conversion processes. Three well-known scaling equations (Bond, Kick, and Rittinger) are used to estimate energy input for grinding minerals and food particles. Previous studies have shown that the Rittinger equation has the best fit to predict energy input for grinding cellulosic biomass. In the Rittinger equation, Rittinger's constant (k R) is independent of the size of ground particles, yet we noted large variations in k R among similar particle size ranges. In this research, the dependence of k R on the physical structure and chemical composition of amore » number of woody materials was explored. Branches from two softwood species (Douglas fir and pine) and two hardwood species (aspen and poplar) were ground in a laboratory knife mill. The recorded data included power input, mass flow rate, and particle size before and after grinding. Nine material properties were determined: particle density, solid density (pycnometer and x-ray diffraction methods), microfibril angle, fiber coarseness, fiber length, and composition (lignin and cellulose glucan contents). The correlation matrix among the nine properties revealed high degrees of interdependence between properties. The k R value had the largest positive correlation (+0.60) with particle porosity across the species tested. As a result, particle density was strongly correlated with lignin content (0.85), microfibril angle (0.71), fiber length (0.87), and fiber coarseness (0.78). An empirical model relating k R to particle density was developed.« less
Decay and nutrient dynamics of coarse woody debris in the Qinling Mountains, China

PubMed Central

Yuan, Jie; Hou, Lin; Wei, Xin; Shang, Zhengchun; Cheng, Fei; Zhang, Shuoxin

2017-01-01

As an ecological unit, coarse woody debris (CWD) plays an essential role in productivity, nutrient cycling, carbon sequestration, community regeneration and biodiversity. However, thus far, the information on quantification the decomposition and nutrient content of CWD in forest ecosystems remains considerably limited. In this study, we conducted a long-term (1996–2013) study on decay and nutrient dynamics of CWD for evaluating accurately the ecological value of CWD on the Huoditang Experimental Forest Farm in the Qinling Mountains, China. The results demonstrated that there was a strong correlation between forest biomass and CWD mass. The single exponential decay model well fit the CWD density loss at this site, and as the CWD decomposed, the CWD density decreased significantly. Annual temperature and precipitation were all significantly correlated with the annual mass decay rate. The K contents and the C/N ratio of the CWD decreased as the CWD decayed, but the C, N, P, Ca and Mg contents increased. We observed a significant CWD decay effect on the soil C, N and Mg contents, especially the soil C content. The soil N, P, K, Ca and Mg contents exhibited large fluctuations, but the variation had no obvious regularity and changed with different decay times. The results showed that CWD was a critical component of nutrient cycling in forest ecosystems. Further research is needed to determine the effect of diameter, plant tissue components, secondary wood compounds, and decomposer organisms on the CWD decay rates in the Qinling Mountains, which will be beneficial to clarifying the role of CWD in carbon cycles of forest ecosystems. PMID:28384317
Facies architecture of the fluvial Missão Velha Formation (Late Jurassic-Early Cretaceous), Araripe Basin, Northeast Brazil: paleogeographic and tectonic implications

NASA Astrophysics Data System (ADS)

Fambrini, Gelson Luís; Neumann, Virgínio Henrique M. L.; Menezes-Filho, José Acioli B.; Da Silva-Filho, Wellington F.; De Oliveira, Édison Vicente

2017-12-01

Sedimentological analysis of the Missão Velha Formation (Araripe Basin, northeast Brazil) is the aim of this paper through detailed facies analysis, architectural elements, depositional systems and paleocurrent data. The main facies recognized were: (i) coarse-grained conglomeratic sandstones, locally pebbly conglomerates, with abundant silicified fossil trunks and several large-to-medium trough cross-stratifications and predominantly lenticular geometry; (ii) lenticular coarse-to-medium sandstones with some granules, abundant silicified fossil wood, and large-to-medium trough cross-stratifications, cut-and fill features and mud drapes on the foresets of cross-strata, (iii) poorly sorted medium-grained sandstones with sparse pebbles and with horizontal stratification, (iv) fine to very fine silty sandstones, laminated, interlayered with (v) decimetric muddy layers with horizontal lamination and climbing-ripple cross-lamination. Nine architectural elements were recognized: CH: Channels, GB: Gravel bars and bed forms, SB: Sand bars and bedforms, SB (p): sand bedform with planar cross-stratification, OF: Overbank flow, DA: Downstream-accretion macroforms, LS: Laminated sandsheet, LA: Lateral-accretion macroforms and FF: Floodplain fines. The lithofacies types and facies associations were interpreted as having been generated by alluvial systems characterized by (i) high energy perennial braided river systems and (ii) ephemeral river systems. Aeolian sand dunes and sand sheets generated by the reworking of braided alluvial deposits can also occur. The paleocurrent measurements show a main dispersion pattern to S, SE and SW, and another to NE/E. These features imply a paleodrainage flowing into the basins of the Recôncavo-Tucano-Jatobá.
Rethinking the role of edaphic condition in halophyte vegetation degradation on salt marshes due to coastal defense structure

NASA Astrophysics Data System (ADS)

Xie, Tian; Cui, Baoshan; Bai, Junhong; Li, Shanze; Zhang, Shuyan

2018-02-01

Determining how human disturbance affects plant community persistence and species conservation is one of the most pressing ecological challenges. The large-scale disturbance form defense structures usually have a long-term and potential effect on phytocommunity in coastal saltmarshes. Coastal defense structures usually remove the effect of tidal wave on tidal salt marshes. As a consequence, edaphic factors such as the salinity and moisture contents are disturbed by tidal action blocking. However, few previous studies have explicitly addressed the response of halophyte species persistence and dynamics to the changing edaphic conditions. The understanding of the response of species composition in seed banks and aboveground vegetation to the stress is important to identify ecological effect of coastal defense structures and provide usefully insight into restoration. Here, we conducted a field study to distinguish the density, species composition and relationships of seed bank with aboveground vegetation between tidal flat wetlands with and without coastal defense structures. We also addressed the role of edaphic condition in vegetation degradation caused by coastal defense structures in combination with field monitor and greenhouse experiments. Our results showed the density of the seed bank and aboveground vegetation in the tidal flat without coastal defense structures was significantly lower than the surrounded flat with coastal defense structures. A total of 14 species were founded in the surrounded flat seed bank and 11 species in the tidal flat, but three species were only recorded in aboveground vegetation of the tidal flat which was much lower than 24 aboveground species in the surrounded flat. The absent of species in aboveground vegetation contributed to low germination rate which depend on the edaphic condition. The germination of seeds in the seed bank were inhabited by high soil salinity in the tidal flat and low soil moisture in the surrounded flat. Our study supported the hypothesis that the change of edaphic condition caused by coastal defense structures was the main reason for the difference of the species composition similarity between aboveground vegetation and the soil seed bank between the tidal and surrounded flats. Therefore, mitigating the hydrological disturbance and maintaining the original state of edaphic factors would be useful implications for reducing the ecological effect of defense structure to vegetation communities in coastal salt marshes.
[Simulating the effects of climate change and fire disturbance on aboveground biomass of boreal forests in the Great Xing'an Mountains, Northeast China].

PubMed

Luo, Xu; Wang, Yu Li; Zhang, Jin Quan

2018-03-01

Predicting the effects of climate warming and fire disturbance on forest aboveground biomass is a central task of studies in terrestrial ecosystem carbon cycle. The alteration of temperature, precipitation, and disturbance regimes induced by climate warming will affect the carbon dynamics of forest ecosystem. Boreal forest is an important forest type in China, the responses of which to climate warming and fire disturbance are increasingly obvious. In this study, we used a forest landscape model LANDIS PRO to simulate the effects of climate change on aboveground biomass of boreal forests in the Great Xing'an Mountains, and compared direct effects of climate warming and the effects of climate warming-induced fires on forest aboveground biomass. The results showed that the aboveground biomass in this area increased under climate warming scenarios and fire disturbance scenarios with increased intensity. Under the current climate and fire regime scenario, the aboveground biomass in this area was (97.14±5.78) t·hm -2 , and the value would increase up to (97.93±5.83) t·hm -2 under the B1F2 scenario. Under the A2F3 scenario, aboveground biomass at landscape scale was relatively higher at the simulated periods of year 100-150 and year 150-200, and the value were (100.02±3.76) t·hm -2 and (110.56±4.08) t·hm -2 , respectively. Compared to the current fire regime scenario, the predicted biomass at landscape scale was increased by (0.56±1.45) t·hm -2 under the CF2 scenario (fire intensity increased by 30%) at some simulated periods, and the aboveground biomass was reduced by (7.39±1.79) t·hm -2 in CF3 scenario (fire intensity increased by 230%) at the entire simulation period. There were significantly different responses between coniferous and broadleaved species under future climate warming scenarios, in that the simulated biomass for both Larix gmelinii and Betula platyphylla showed decreasing trend with climate change, whereas the simulated biomass for Pinus sylvestris var. mongolica, Picea koraiensis and Populus davidiana showed increasing trend at different degrees during the entire simulation period. There was a time lag for the direct effect of climate warming on biomass for coniferous and broadleaved species. The response time of coniferous species to climate warming was 25-30 years, which was longer than that for broadleaf species. The forest landscape in the Great Xing'an Mountains was sensitive to the interactive effect of climate warming (high CO 2 emissions) and high intensity fire disturbance. Future climate warming and high intensity forest fire disturbance would significantly change the composition and structure of forest ecosystem.
Implications of allometric model selection for county-level biomass mapping

Treesearch

Laura Duncanson; Wenli Huang; Kristofer Johnson; Anu Swatantran; Ronald E. McRoberts; Ralph Dubayah

2017-01-01

Background: Carbon accounting in forests remains a large area of uncertainty in the global carbon cycle. Forest aboveground biomass is therefore an attribute of great interest for the forest management community, but the accuracy of aboveground biomass maps depends on the accuracy of the underlying field estimates used to calibrate models. These field estimates depend...
Relationship between aboveground biomass and multiple measures of biodiversity in subtropical forest of Puerto Rico

Treesearch

Heather D. Vance-Chalcraft; Michael R. Willig; Stephen B. Cox; Ariel E. Lugo; Frederick N. Scatena

2010-01-01

Anthropogenic activities have accelerated the rate of global loss of biodiversity, making it more important than ever to understand the structure of biodiversity hotspots. One current focus is the relationship between species richness and aboveground biomass (AGB) in a variety of ecosystems. Nonetheless, species diversity, evenness, rarity, or dominance represent other...
Aboveground biomass and nutrient accumulation 20 years after clear-cutting a southern Appalachian watershed

Treesearch

Katherine J. Elliott; Lindsay R. Boring; Wayne T. Swank

2002-01-01

In 1975, we initiated a long-term interdisciplinary study of forest watershed ecosystem response to clear- cutting and cable logging in watershed 7 at the Coweeta Hydrologic Laboratory in the southern Appalachian Mountains of North Carolina. This paper describes ~20 years of change in species composition, aboveground biomass, leaf area index (LAI),...
Regional contingencies in the relationship between aboveground biomass and litter in the world’s grasslands

Treesearch

L.R. O' Halloran; E.T. Borer; E.W. Seabloom; A.S. MacDougall; E.E. Cleland; R.L. McCulley; S. Hobbie; S. Harpole; N.M. DeCrappeo; C.-J. Chu; J.D. Bakker; K.F. Davies; G. Du; J. Firn; N. Hagenah; K.S. Hofmockel; J.M.H. Knops; W. Li; B.A. Melbourne; J.W. Morgan; J.L. Orrock; S.M. Prober; C.J. Stevens

2013-01-01

Based on regional-scale studies, aboveground production and litter decomposition are thought to positively covary, because they are driven by shared biotic and climatic factors. Until now we have been unable to test whether production and decomposition are generally coupled across climatically dissimilar regions, because we lacked replicated data collected within a...
Does biodiversity make a difference? Relationships between species richness, evolutionary diversity, and aboveground live tree biomass across US forests

Treesearch

Kevin M. Potter; Christopher W. Woodall

2014-01-01

Biodiversity conveys numerous functional benefits to forested ecosystems, including community stability and resilience. In the context of managing forests for climate change mitigation/adaptation, maximizing and/or maintaining aboveground biomass will require understanding the interactions between tree biodiversity, site productivity, and the stocking of live trees....
A Comparison of Two Above-Ground Biomass Estimation Techniques Integrating Satellite-Based Remotely Sensed Data and Ground Data for Tropical and Semiarid Forests in Puerto Rico

EPA Science Inventory

Two above-ground forest biomass estimation techniques were evaluated for the United States Territory of Puerto Rico using predictor variables acquired from satellite based remotely sensed data and ground data from the U.S. Department of Agriculture Forest Inventory Analysis (FIA)...
Environmental and biotic controls over aboveground biomass throughout a tropical rainforest

Treesearch

G.P. Asner; R.F. Hughes; T.A. Varga; D.E. Knapp; T. Kennedy-Bowdoin

2009-01-01

The environmental and biotic factors affecting spatial variation in canopy three-dimensional (3-D) structure and aboveground tree biomass (AGB) are poorly understood in tropical rain forests. We combined field measurements and airborne light detection and ranging (lidar) to quantify 3-D structure and AGB across a 5,016 ha rain forest reserve on the...

Tradeoffs in overstory and understory aboveground net primary productivity in southwestern ponderosa pine stands

Treesearch

Kyla E. Sabo; Stephen C. Hart; Carolyn Hull Sieg; John Duff Bailey

2008-01-01

Previous studies in ponderosa pine forests have quantified the relationship between overstory stand characteristics and understory production using tree measurements such as basal area. We built on these past studies by evaluating the tradeoff between overstory and understory aboveground net primary productivity (ANPP) in southwestern ponderosa pine forests at the...
Patterns of covariance between forest stand and canopy structure in the Pacific Northwest.

Treesearch

Michael A. Lefsky; Andrew T. Hudak; Warren B. Cohen; S.A. Acker

2005-01-01

In the past decade, LIDAR (light detection and ranging) has emerged as a powerful tool for remotely sensing forest canopy and stand structure, including the estimation of aboveground biomass and carbon storage. Numerous papers have documented the use of LIDAR measurements to predict important aspects of forest stand structure, including aboveground biomass. Other...
Modeling and Mapping Agroforestry Aboveground Biomass in the Brazilian Amazon Using Airborne Lidar Data

Treesearch

Qi Chen; Dengsheng Lu; Michael Keller; Maiza dos-Santos; Edson Bolfe; Yunyun Feng; Changwei Wang

2015-01-01

Agroforestry has large potential for carbon (C) sequestration while providing many economical, social, and ecological benefits via its diversified products. Airborne lidar is considered as the most accurate technology for mapping aboveground biomass (AGB) over landscape levels. However, little research in the past has been done to study AGB of agroforestry systems...
Satellite detection of land-use change and effects on regional forest aboveground biomass estimates

Treesearch

Daolan Zheng; Linda S. Heath; Mark J. Ducey

2008-01-01

We used remote-sensing-driven models to detect land-cover change effects on forest aboveground biomass (AGB) density (Mg·ha−1, dry weight) and total AGB (Tg) in Minnesota, Wisconsin, and Michigan USA, between the years 1992-2001, and conducted an evaluation of the approach. Inputs included remotely-sensed 1992 reflectance data...
Primary production and carbon allocation in relation to nutrient supply in a tropical experimental forest

Treesearch

Christian P. Giardina; Michael G. Ryan; Dan Binkley; Dan Binkley; James H. Fownes

2003-01-01

Nutrient supply commonly limits aboveground plant productivity in forests, but the effects of an altered nutrient supply on gross primary production (GPP) and patterns of carbon (C) allocation remain poorly characterized. Increased nutrient supply may lead to a higher aboveground net primary production (ANPP), but a lower total belowground carbon allocation (TBCA),...
Landscape-scale analysis of aboveground tree carbon stocks affected by mountain pine beetles in Idaho

Treesearch

Benjamin Bright; J. A. Hicke; A. T. Hudak

2012-01-01

Bark beetle outbreaks kill billions of trees in western North America, and the resulting tree mortality can significantly impact local and regional carbon cycling. However, substantial variability in mortality occurs within outbreak areas. Our objective was to quantify landscape-scale effects of beetle infestations on aboveground carbon (AGC) stocks using field...
Early forest thinning changes aboveground carbon distribution among pools, but not total amount

Treesearch

Michael S. Schaedel; Andrew J. Larson; David L. R. Affleck; Travis Belote; John M. Goodburn; Deborah S. Page-Dumroese

2017-01-01

Mounting concerns about global climate change have increased interest in the potential to use common forest management practices, such as forest density management with thinning, in climate change mitigation and adaptation efforts. Long-term effects of forest density management on total aboveground C are not well understood, especially for precommercial thinning (PCT)...
Estimates of forest canopy height and aboveground biomass using ICESat.

Treesearch

Michael A. Lefsky; David J. Harding; Michael Keller; Warren B. Cohen; Claudia C. Carabajal; Fernando Del Bom Espirito-Santo; Maria O. Hunter; Raimundo de Oliveira Jr.

2005-01-01

Exchange of carbon between forests and the atmosphere is a vital component of the global carbon cycle. Satellite laser altimetry has a unique capability for estimating forest canopy height, which has a direct and increasingly well understood relationship to aboveground carbon storage. While the Geoscience Laser Altimeter System (GLAS) onboard the Ice, Cloud and land...
Architecture of the wood-wide web: Rhizopogon spp. genets link multiple Douglas-fir cohorts.

PubMed

Beiler, Kevin J; Durall, Daniel M; Simard, Suzanne W; Maxwell, Sheri A; Kretzer, Annette M

2010-01-01

*The role of mycorrhizal networks in forest dynamics is poorly understood because of the elusiveness of their spatial structure. We mapped the belowground distribution of the fungi Rhizopogon vesiculosus and Rhizopogon vinicolor and interior Douglas-fir trees (Pseudotsuga menziesii var. glauca) to determine the architecture of a mycorrhizal network in a multi-aged old-growth forest. *Rhizopogon spp. mycorrhizas were collected within a 30 x 30 m plot. Trees and fungal genets were identified using multi-locus microsatellite DNA analysis. Tree genotypes from mycorrhizas were matched to reference trees aboveground. Two trees were considered linked if they shared the same fungal genet(s). *The two Rhizopogon species each formed 13-14 genets, each colonizing up to 19 trees in the plot. Rhizopogon vesiculosus genets were larger, occurred at greater depths, and linked more trees than genets of R. vinicolor. Multiple tree cohorts were linked, with young saplings established within the mycorrhizal network of Douglas-fir veterans. A strong positive relationship was found between tree size and connectivity, resulting in a scale-free network architecture with small-world properties. *This mycorrhizal network architecture suggests an efficient and robust network, where large trees play a foundational role in facilitating conspecific regeneration and stabilizing the ecosystem.
Tree- Rings Link Climate and Carbon Storage in a Northern Mixed Hardwood Forest

NASA Astrophysics Data System (ADS)

Chiriboga, A.

2007-12-01

The terrestrial biosphere is a variable sink for atmospheric carbon dioxide. It is important to understand how carbon storage in trees is affected by natural climate variability to better characterize the sink. Quantifying the sensitivity of forest carbon storage to climate will improve carbon budgets and have implications for forest management practices. Here we explore how climate variability affects the ability of a northern mixed hardwood forest in Michigan to sequester atmospheric carbon dioxide in woody tissues. This site is ideal for studies of carbon sequestration; The University of Michigan Biological Station is an Ameriflux site, and has detailed meteorological and biometric records, as well as CO2 flux data. We have produced an 82- year aspen (Populus grandidentata) tree-ring chronology for this site, and measured ring widths at several heights up the bole. These measurements were used to estimate annual wood volume, which represents carbon allocated to aboveground carbon stores. Standard dendroclimatological techniques are used to identify environmental factors (e.g. temperature or precipitation) that drive tree-ring increment variability in the past century, and therefore annual carbon storage in this forest. Preliminary results show that marker years within the tree- ring chronology correspond with years that have cold spring temperatures. This suggests that trees at this site are temperature sensitive.
Remote Imaging Applied to Schistosomiasis Control: The Anning River Project

NASA Technical Reports Server (NTRS)

Seto, Edmund Y. W.; Maszle, Don R.; Spear, Robert C.; Gong, Peng

1997-01-01

The use of satellite imaging to remotely detect areas of high risk for transmission of infectious disease is an appealing prospect for large-scale monitoring of these diseases. The detection of large-scale environmental determinants of disease risk, often called landscape epidemiology, has been motivated by several authors (Pavlovsky 1966; Meade et al. 1988). The basic notion is that large-scale factors such as population density, air temperature, hydrological conditions, soil type, and vegetation can determine in a coarse fashion the local conditions contributing to disease vector abundance and human contact with disease agents. These large-scale factors can often be remotely detected by sensors or cameras mounted on satellite or aircraft platforms and can thus be used in a predictive model to mark high risk areas of transmission and to target control or monitoring efforts. A review of satellite technologies for this purpose was recently presented by Washino and Wood (1994) and Hay (1997) and Hay et al. (1997).
Geomorphic Unit Tool (GUT): Applications of Fluvial Mapping

NASA Astrophysics Data System (ADS)

Kramer, N.; Bangen, S. G.; Wheaton, J. M.; Bouwes, N.; Wall, E.; Saunders, C.; Bennett, S.; Fortney, S.

2017-12-01

Geomorphic units are the building blocks of rivers and represent distinct habitat patches for many fluvial organisms. We present the Geomorphic Unit Toolkit (GUT), a flexible GIS geomorphic unit mapping tool, to generate maps of fluvial landforms from topography. GUT applies attributes to landforms based on flow stage (Tier 1), topographic signatures (Tier 2), geomorphic characteristics (Tier 3) and patch characteristics (Tier 4) to derive attributed maps at the level of detail required by analysts. We hypothesize that if more rigorous and consistent geomorphic mapping is conducted, better correlations between physical habitat units and ecohydraulic model results will be obtained compared to past work. Using output from GUT for coarse bed tributary streams in the Columbia River Basin, we explore relationships between salmonid habitat and geomorphic spatial metrics. We also highlight case studies of how GUT can be used to showcase geomorphic impact from large wood restoration efforts. Provided high resolution topography exists, this tool can be used to quickly assess changes in fluvial geomorphology in watersheds impacted by human activities.
Large-scale carbon stock assessment of woody vegetation in tropical dry deciduous forest of Sathanur reserve forest, Eastern Ghats, India.

PubMed

Gandhi, Durai Sanjay; Sundarapandian, Somaiah

2017-04-01

Tropical dry forests are one of the most widely distributed ecosystems in tropics, which remain neglected in research, especially in the Eastern Ghats. Therefore, the present study was aimed to quantify the carbon storage in woody vegetation (trees and lianas) on large scale (30, 1 ha plots) in the dry deciduous forest of Sathanur reserve forest of Eastern Ghats. Biomass of adult (≥10 cm DBH) trees was estimated by species-specific allometric equations using diameter and wood density of species whereas in juvenile tree population and lianas, their respective general allometric equations were used to estimate the biomass. The fractional value 0.4453 was used to convert dry biomass into carbon in woody vegetation of tropical dry forest. The mean aboveground biomass value of juvenile tree population was 1.86 Mg/ha. The aboveground biomass of adult trees ranged from 64.81 to 624.96 Mg/ha with a mean of 245.90 Mg/ha. The mean aboveground biomass value of lianas was 7.98 Mg/ha. The total biomass of woody vegetation (adult trees + juvenile population of trees + lianas) ranged from 85.02 to 723.46 Mg/ha, with a mean value of 295.04 Mg/ha. Total carbon accumulated in woody vegetation in tropical dry deciduous forest ranged from 37.86 to 322.16 Mg/ha with a mean value of 131.38 Mg/ha. Adult trees accumulated 94.81% of woody biomass carbon followed by lianas (3.99%) and juvenile population of trees (1.20%). Albizia amara has the greatest biomass and carbon stock (58.31%) among trees except for two plots (24 and 25) where Chloroxylon swietenia contributed more to biomass and carbon stock. Similarly, Albizia amara (52.4%) showed greater carbon storage in juvenile population of trees followed by Chloroxylon swietenia (21.9%). Pterolobium hexapetalum (38.86%) showed a greater accumulation of carbon in liana species followed by Combretum albidum (33.04%). Even though, all the study plots are located within 10 km radius, they show a significant spatial variation among them in terms of biomass and carbon stocks which could be attributed to variation in anthropogenic pressures among the plots as well as to changes in tree density across landscapes. Total basal area of woody vegetation showed a significant positive (R 2 = 0.978; P = 0.000) relationship with carbon storage while juvenile tree basal area showed the negative relationship (R 2 = 0.4804; P = 0.000) with woody carbon storage. The present study generates a large-scale baseline data of dry deciduous forest carbon stock, which would facilitate carbon stock assessment at a national level as well as to understand its contribution on a global scale.
Conversion of tropical lowland forest reduces nutrient return through litterfall, and alters nutrient use efficiency and seasonality of net primary production.

PubMed

Kotowska, Martyna M; Leuschner, Christoph; Triadiati, Triadiati; Hertel, Dietrich

2016-02-01

Tropical landscapes are not only rapidly transformed by ongoing land-use change, but are additionally confronted by increasing seasonal climate variation. There is an increasing demand for studies analyzing the effects and feedbacks on ecosystem functioning of large-scale conversions of tropical natural forest into intensively managed cash crop agriculture. We analyzed the seasonality of aboveground litterfall, fine root litter production, and aboveground woody biomass production (ANPP(woody)) in natural lowland forests, rubber agroforests under natural tree cover ("jungle rubber"), rubber and oil palm monocultures along a forest-to-agriculture transformation gradient in Sumatra. We hypothesized that the temporal fluctuation of litter production increases with increasing land-use intensity, while the associated nutrient fluxes and nutrient use efficiency (NUE) decrease. Indeed, the seasonal variation of aboveground litter production and ANPP(woody) increased from the natural forest to the plantations, while aboveground litterfall generally decreased. Nutrient return through aboveground litter was mostly highest in the natural forest; however, it was significantly lower only in rubber plantations. NUE of N, P and K was lowest in the oil palm plantations, with natural forest and the rubber systems showing comparably high values. Root litter production was generally lower than leaf litter production in all systems, while the root-to-leaf ratio of litter C flux increased along the land-use intensity gradient. Our results suggest that nutrient and C cycles are more directly affected by climate seasonality in species-poor agricultural systems than in species-rich forests, and therefore might be more susceptible to inter-annual climate fluctuation and climate change.
Shifts in Aboveground Biomass Allocation Patterns of Dominant Shrub Species across a Strong Environmental Gradient

PubMed Central

Kumordzi, Bright B.; Gundale, Michael J.; Nilsson, Marie-Charlotte; Wardle, David A.

2016-01-01

Most plant biomass allocation studies have focused on allocation to shoots versus roots, and little is known about drivers of allocation for aboveground plant organs. We explored the drivers of within-and between-species variation of aboveground biomass allocation across a strong environmental resource gradient, i.e., a long-term chronosequence of 30 forested islands in northern Sweden across which soil fertility and plant productivity declines while light availability increases. For each of the three coexisting dominant understory dwarf shrub species on each island, we estimated the fraction of the total aboveground biomass produced year of sampling that was allocated to sexual reproduction (i.e., fruits), leaves and stems for each of two growing seasons, to determine how biomass allocation responded to the chronosequence at both the within-species and whole community levels. Against expectations, within-species allocation to fruits was least on less fertile islands, and allocation to leaves at the whole community level was greatest on intermediate islands. Consistent with expectations, different coexisting species showed contrasting allocation patterns, with the species that was best adapted for more fertile conditions allocating the most to vegetative organs, and with its allocation pattern showing the strongest response to the gradient. Our study suggests that co-existing dominant plant species can display highly contrasting biomass allocations to different aboveground organs within and across species in response to limiting environmental resources within the same plant community. Such knowledge is important for understanding how community assembly, trait spectra, and ecological processes driven by the plant community vary across environmental gradients and among contrasting ecosystems. PMID:27270445
Forest Restoration Carbon Analysis of Baseline Carbon Emissions and Removal in Tropical Rainforest at La Selva Central, Peru

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patrick Gonzalez; Benjamin Kroll; Carlos R. Vargas

Conversion of tropical forest to agricultural land and pasture has reduced forest extent and the provision of ecosystem services, including watershed protection, biodiversity conservation, and carbon sequestration. Forest conservation and reforestation can restore those ecosystem services. We have assessed forest species patterns, quantified deforestation and reforestation rates, and projected future baseline carbon emissions and removal in Amazon tropical rainforest at La Selva Central, Peru. The research area is a 4800 km{sup 2} buffer zone around the Parque Nacional Yanachaga-Chemillen, Bosque de Proteccion San Matias-San Carlos, and the Reserva Comunal Yanesha. A planned project for the period 2006-2035 would conserve 4000more » ha of forest in a proposed 7000 ha Area de Conservacion Municipale de Chontabamba and establish 5600 ha of natural regeneration and 1400 ha of native species plantations, laid out in fajas de enriquecimiento (contour plantings), to reforest 7000 ha of agricultural land. Forest inventories of seven sites covering 22.6 ha in primary forest and 17 sites covering 16.5 ha in secondary forest measured 17,073 trees of diameter {ge} 10 cm. The 24 sites host trees of 512 species, 267 genera, and 69 families. We could not identify the family of 7% of the trees or the scientific species of 21% of the trees. Species richness is 346 in primary forest and 257 in the secondary forest. In primary forest, 90% of aboveground biomass resides in old-growth species. Conversely, in secondary forest, 66% of aboveground biomass rests in successional species. The density of trees of diameter {ge} 10 cm is 366 trees ha{sup -1} in primary forest and 533 trees ha{sup -1} in secondary forest, although the average diameter is 24 {+-} 15 cm in primary forest and 17 {+-} 8 cm in secondary forest. Using Amazon forest biomass equations and wood densities for 117 species, aboveground biomass is 240 {+-} 30 t ha{sup -1} in the primary sites and 90 {+-} 10 t ha{sup -1} in the secondary sites. Aboveground carbon density is 120 {+-} 15 t ha{sup -1} in primary forest and 40 {+-} 5 t ha{sup -1} in secondary forest. Forest stands in the secondary forest sites range in age from 10 to 42 y. Growth in biomass (t ha{sup -1}) as a function of time (y) follows the relation: biomass = 4.09-0.017 age{sup 2} (p < 0.001). Aboveground biomass and forest species richness are positively correlated (r{sup 2} = 0.59, p < 0.001). Analyses of Landsat data show that the land cover of the 3700 km{sup 2} of non-cloud areas in 1999 was: closed forest 78%; open forest 12%, low vegetation cover 4%, sparse vegetation cover 6%. Deforestation from 1987 to 1999 claimed a net 200 km{sup 2} of forest, proceeding at a rate of 0.005 y{sup -1}. Of those areas of closed forest in 1987, only 89% remained closed forest in 1999. Consequently, closed forests experienced disruption in the time period at double the rate of net deforestation. The three protected areas experienced negligible deforestation or slight reforestation. Based on 1987 forest cover, 26,000 ha are eligible for forest carbon trading under the Clean Development Mechanism, established by the Kyoto Protocol to the United Nations Framework Convention on Climate Change. Principal components analysis showed that distance to nonforest was the factor that best explained observed patterns of deforestation while distance to forest best explained observed patterns of reforestation, more significant than elevation, distance to rivers, distance to roads, slope, and distance to towns of population > 400. Aboveground carbon in live vegetation in the project area decreased from 35 million {+-} 4 million t in 1987 to 34 million {+-} 4 million t in 1999. Projected aboveground carbon in live vegetation would fall to 33 million {+-} 4 million t in 2006, 32 million {+-} 4 million t in 2011, and 29 million {+-} 3 million t in 2035. Projected net deforestation in the research area would total 13,000 {+-} 3000 ha in the period 1999-2011, proceeding at a rate of 0.003 {+-} 0.0007 y{sup -1}, and would total 33,000 {+-} 7000 ha in the period 2006-2035. The proposed 7000 ha of forest conservation could prevent gross baseline deforestation of 100 ha (min. 70 ha, max 150 ha) in the period 2006-2035, averting baseline carbon emissions of 10,000 t (min. 6 000 t, max. 18 000 t). Projected gross reforestation in the research area would total 8500 {+-} 1500 ha in the period 1999-2011, proceeding at a rate of 0.0012 y{sup -1} (min. 0.01 y{sup -1}, max. 0.014 y{sup -1}), and would total 24,000 {+-} 4000 ha in the period 2006-2035. Gross baseline reforestation for the proposed 7000 ha of reforestation would total 2600 {+-} 400 ha in the period 2006-2035, representing a baseline removal from the atmosphere of 73,000 t carbon (min. 30,000 t, max. 120,000 t). The proposed reforestation project could sequester 230,000 t carbon (min. 140,000 t, max. 310,000 t) above baseline removal in the period 2006-2035.« less
Element Pool Changes within a Scrub-Oak Ecosystem after 11 Years of Exposure to Elevated CO2

PubMed Central

Duval, Benjamin D.; Dijkstra, Paul; Drake, Bert G.; Johnson, Dale W.; Ketterer, Michael E.; Megonigal, J. Patrick; Hungate, Bruce A.

2013-01-01

The effects of elevated CO2 on ecosystem element stocks are equivocal, in part because cumulative effects of CO2 on element pools are difficult to detect. We conducted a complete above and belowground inventory of non-nitrogen macro- and micronutrient stocks in a subtropical woodland exposed to twice-ambient CO2 concentrations for 11 years. We analyzed a suite of nutrient elements and metals important for nutrient cycling in soils to a depth of ∼2 m, in leaves and stems of the dominant oaks, in fine and coarse roots, and in litter. In conjunction with large biomass stimulation, elevated CO2 increased oak stem stocks of Na, Mg, P, K, V, Zn and Mo, and the aboveground pool of K and S. Elevated CO2 increased root pools of most elements, except Zn. CO2-stimulation of plant Ca was larger than the decline in the extractable Ca pool in soils, whereas for other elements, increased plant uptake matched the decline in the extractable pool in soil. We conclude that elevated CO2 caused a net transfer of a subset of nutrients from soil to plants, suggesting that ecosystems with a positive plant growth response under high CO2 will likely cause mobilization of elements from soil pools to plant biomass. PMID:23717607
Family Differences Influence the Aboveground Biomass of Loblolly Pine Plantations

Treesearch

P.E. Pope; D.L. Graney

1979-01-01

We compared the aboveground biomass of 4 half-sib families of loblolly pine (Pinus taeda L.) 11 years after planting. Total dry weights differed significantly among families in plantations on the same soil type with the same site index. Differences in biomass resulted from differences in stem form and branch size. Distribution of growth -the proportion of tree weight...
Using landsat time-series and lidar to inform aboveground carbon baseline estimation in Minnesota

Treesearch

Ram K. Deo; Grant M. Domke; Matthew B. Russell; Christopher W. Woodall; Michael J. Falkowski

2015-01-01

Landsat data has long been used to support forest monitoring and management decisions despite the limited success of passive optical remote sensing for accurate estimation of structural attributes such as aboveground biomass. The archive of publicly available Landsat images dating back to the 1970s can be used to predict historic forest biomass dynamics. In addition,...
Guidelines for sampling aboveground biomass and carbon in mature central hardwood forests

Treesearch

Martin A. Spetich; Stephen R. Shifley

2017-01-01

As impacts of climate change expand, determining accurate measures of forest biomass and associated carbon storage in forests is critical. We present sampling guidance for 12 combinations of percent error, plot size, and alpha levels by disturbance regime to help determine the optimal size of plots to estimate aboveground biomass and carbon in an old-growth Central...

Methods for estimating aboveground biomass and its components for five Pacific Northwest tree species

Treesearch

Krishna P. Poudel; Temesgen. Hailemariam

2015-01-01

Performance of three groups of methods to estimate total and/or component aboveground biomass was evaluated using the data collected from destructively sampled trees in different parts of Oregon. First group of methods used analytical approach to estimate total and component biomass using existing equations, and produced biased estimates for our dataset. The second...
Drivers of variation in aboveground net primary productivity and plant community composition differe across a broad precipitation gradient

USDA-ARS?s Scientific Manuscript database

It has long been a goal of ecology to determine what factors drive variation in aboveground net primary production (ANPP). Total annual precipitation has been shown to be a strong predictor of ANPP across broad spatial scales, but a poor predictor at local scales. Here we aim to determine the amount...
A comparison of above-ground dry-biomass estimators for trees in the Northeastern United States

Treesearch

James A. Westfall

2012-01-01

In the northeastern United States, both component and total aboveground tree dry-biomass estimates are available from several sources. In this study, comparisons were made among four methods to promote understanding of the similarities and differences in live-tree biomass estimators. The methods use various equations developed from biomass data collected in the United...
Description and prediction of individual tree biomass on pinon (Pinus edulis) in northern New Mexico

Treesearch

Mark Loveall; John T. Harrington

2008-01-01

The purpose of this study was to gain reliable information on the distribution of aboveground biomass of an important component of the woodlands of north-central New Mexico, and to develop prediction equations that may be used to quickly compute biomass from relatively simple field measurements. Improved understanding of and ability to predict aboveground biomass...
Below- and above-ground effects of deadwood and termites in plantation forests

Treesearch

Michael D. Ulyshen; Richard Shefferson; Scott Horn; Melanie K. Taylor; Bryana Bush; Cavell Brownie; Sebastian Seibold; Michael S. Strickland

2017-01-01

Deadwood is an important legacy structure in managed forests, providing continuity in shelter and resource availability for many organisms and acting as a vehicle by which nutrients can be passed from one stand to the next following a harvest. Despite existing at the interface between below- and above-ground systems, however, much remains unknown about the role woody...
Weight and Nutrient Content of the Aboveground Parts of Some Loblolly Pines

Treesearch

Louis J. Metz; Carol G. Wells

1965-01-01

During the course of a study on the nutrient content of foliage of loblolly pine (Pinus taeda), weight determinations and nutrient analyses were made on all aboveground parts of 10 trees. The data, although limited in scope, are being presented because of the scarcity of such information in the literature, and should be helpful to those interested in...
Aboveground production and nutrient circulation along a flooding gradient in a South Carolina Coastal Plain forest

Treesearch

B. Graeme Lockaby; William H. Conner

1999-01-01

Relative to effects of flooding, little is known about the influence of hydrology-nutrient interactions on aboveground net primary production (NPP) in forested wetlands. The authors found that nutrient circulation and NPP were closely related along a complex physical, chemical, and hydrologic gradient in a bottomland hardwood forest with four distinct communities....
Regional applicability of forest height and aboveground biomass models for the Geoscience Laser Altimeter System

Treesearch

Dirk Pflugmacher; Warren B. Cohen; Robert E. Kennedy; Michael. Lefsky

2008-01-01

Accurate estimates of forest aboveground biomass are needed to reduce uncertainties in global and regional terrestrial carbon fluxes. In this study we investigated the utility of the Geoscience Laser Altimeter System (GLAS) onboard the Ice, Cloud and land Elevation Satellite for large-scale biomass inventories. GLAS is the first spaceborne lidar sensor that will...
Quantifying aboveground forest carbon pools and fluxes from repeat LiDAR surveys

Treesearch

Andrew T. Hudak; Eva K. Strand; Lee A. Vierling; John C. Byrne; Jan U. H. Eitel; Sebastian Martinuzzi; Michael J. Falkowski

2012-01-01

Sound forest policy and management decisions to mitigate rising atmospheric CO2 depend upon accurate methodologies to quantify forest carbon pools and fluxes over large tracts of land. LiDAR remote sensing is a rapidly evolving technology for quantifying aboveground biomass and thereby carbon pools; however, little work has evaluated the efficacy of repeat LiDAR...
Statistical rigor in LiDAR-assisted estimation of aboveground forest biomass

Treesearch

Timothy G. Gregoire; Erik Næsset; Ronald E. McRoberts; Göran Ståhl; Hans Andersen; Terje Gobakken; Liviu Ene; Ross Nelson

2016-01-01

For many decades remotely sensed data have been used as a source of auxiliary information when conducting regional or national surveys of forest resources. In the past decade, airborne scanning LiDAR (Light Detection and Ranging) has emerged as a promising tool for sample surveys aimed at improving estimation of aboveground forest biomass. This technology is now...
Aboveground biomass variability across intact and degraded forests in the Brazilian Amazon

Treesearch

Marcos Longo; Michael Keller; Maiza N. dos-Santos; Veronika Leitold; Ekena R. Pinagé; Alessandro Baccini; Sassan Saatchi; Euler M. Nogueira; Mateus Batistella; Douglas C. Morton

2016-01-01

Deforestation rates have declined in the Brazilian Amazon since 2005, yet degradation from logging, fire, and fragmentation has continued in frontier forests. In this study we quantified the aboveground carbon density (ACD) in intact and degraded forests using the largest data set of integrated forest inventory plots (n = 359) and airborne lidar data (18,000 ha)...
Comparison and Intercalibration of Vegetation Indices from Different Sensors for Monitoring Above-Ground Plant Nitrogen Uptake in Winter Wheat

PubMed Central

Yao, Xinfeng; Yao, Xia; Jia, Wenqing; Tian, Yongchao; Ni, Jun; Cao, Weixing; Zhu, Yan

2013-01-01

Various sensors have been used to obtain the canopy spectral reflectance for monitoring above-ground plant nitrogen (N) uptake in winter wheat. Comparison and intercalibration of spectral reflectance and vegetation indices derived from different sensors are important for multi-sensor data fusion and utilization. In this study, the spectral reflectance and its derived vegetation indices from three ground-based sensors (ASD Field Spec Pro spectrometer, CropScan MSR 16 and GreenSeeker RT 100) in six winter wheat field experiments were compared. Then, the best sensor (ASD) and its normalized difference vegetation index (NDVI (807, 736)) for estimating above-ground plant N uptake were determined (R2 of 0.885 and RMSE of 1.440 g·N·m−2 for model calibration). In order to better utilize the spectral reflectance from the three sensors, intercalibration models for vegetation indices based on different sensors were developed. The results indicated that the vegetation indices from different sensors could be intercalibrated, which should promote application of data fusion and make monitoring of above-ground plant N uptake more precise and accurate. PMID:23462622
Coupling of soil prokaryotic diversity and plant diversity across latitudinal forest ecosystems

NASA Astrophysics Data System (ADS)

Wang, Jun-Tao; Zheng, Yuan-Ming; Hu, Hang-Wei; Li, Jing; Zhang, Li-Mei; Chen, Bao-Dong; Chen, Wei-Ping; He, Ji-Zheng

2016-01-01

The belowground soil prokaryotic community plays a cardinal role in sustaining the stability and functions of forest ecosystems. Yet, the nature of how soil prokaryotic diversity co-varies with aboveground plant diversity along a latitudinal gradient remains elusive. By establishing three hundred 400-m2 quadrats from tropical rainforest to boreal forest in a large-scale parallel study on both belowground soil prokaryote and aboveground tree and herb communities, we found that soil prokaryotic diversity couples with the diversity of herbs rather than trees. The diversity of prokaryotes and herbs responds similarly to environmental factors along the latitudinal gradient. These findings revealed that herbs provide a good predictor of belowground biodiversity in forest ecosystems, and provide new perspective on the aboveground and belowground interactions in forest ecosystems.
Coupling of soil prokaryotic diversity and plant diversity across latitudinal forest ecosystems.

PubMed

Wang, Jun-Tao; Zheng, Yuan-Ming; Hu, Hang-Wei; Li, Jing; Zhang, Li-Mei; Chen, Bao-Dong; Chen, Wei-Ping; He, Ji-Zheng

2016-01-19

The belowground soil prokaryotic community plays a cardinal role in sustaining the stability and functions of forest ecosystems. Yet, the nature of how soil prokaryotic diversity co-varies with aboveground plant diversity along a latitudinal gradient remains elusive. By establishing three hundred 400-m(2) quadrats from tropical rainforest to boreal forest in a large-scale parallel study on both belowground soil prokaryote and aboveground tree and herb communities, we found that soil prokaryotic diversity couples with the diversity of herbs rather than trees. The diversity of prokaryotes and herbs responds similarly to environmental factors along the latitudinal gradient. These findings revealed that herbs provide a good predictor of belowground biodiversity in forest ecosystems, and provide new perspective on the aboveground and belowground interactions in forest ecosystems.
Linking tree demography to climate change feedbacks: fire, larch forests, and carbon pools of the Siberian Arctic

NASA Astrophysics Data System (ADS)

Alexander, H. D.; Loranty, M. M.; Natali, S.; Pena, H., III; Ludwig, S.; Spektor, V.; Davydov, S. P.; Zimov, N.; Mack, M. C.

2017-12-01

Fire severity is increasing in larch forests of the Siberian Arctic as climate warms, and initial fire impacts on tree demographic processes could be an especially important determinant of long-term forest structure and carbon (C) dynamics. We hypothesized that (1) larch forest regrowth post-fire is largely determined by residual soil organic layer (SOL) depth because of the SOL's role as a seedbed and thermal regulator, and (2) changes in post-fire larch recruitment impact C accumulation through stand density impacts on understory microclimate and permafrost thaw. We tested these hypotheses by (1) experimentally creating a soil burn severity gradient in a Cajander larch (Larix cajanderi Mayr.) forest near Cherskiy, Russia and (2) quantifying C pools across a stand density gradient within a 75-year old fire scar. From 2012-2015, we added larch seeds to plots burned at different severities and monitored recruitment along with permafrost and active layer (i.e., subject to annual freeze-thaw) conditions (SOL depth, temperature, moisture, and thaw depth). Across the density gradient, we inventoried larch trees and harvested ground-layer vegetation to estimate aboveground contribution to C pools. We quantified woody debris C pools and sampled belowground C pools (soil, fine roots, and coarse roots) in the organic + upper (0-10 cm) mineral soil. Larch recruits were rare in unburned and low severity plots, but a total of 6 new germinants m-2 were tallied in moderate and high severity plots during the study. Seedling survival for > 1 year was only 40 and 25% on moderate and high severity treatments, respectively, but yielded net larch recruitment of 2 seedlings m-2, compared to 0.3 seedlings m-2 on low severity plots. Density of both total and established recruits increased with decreasing residual SOL depth, which correlated with increased soil temperature, moisture, and thaw depth. At 75-year post-fire, total C pools increased with increased larch density, largely due to increased tree aboveground C pools and decreased ground-layer vegetation C pools, which corresponded to higher canopy cover, cooler soils, and shallower active layer depths. Our findings highlight the potential for a climate-driven increase in fire severity to alter tree recruitment, successional dynamics, and C cycling in Siberian larch forests.
Forest structure and carbon dynamics in Amazonian tropical rain forests.

PubMed

Vieira, Simone; de Camargo, Plinio Barbosa; Selhorst, Diogo; da Silva, Roseana; Hutyra, Lucy; Chambers, Jeffrey Q; Brown, I Foster; Higuchi, Niro; dos Santos, Joaquim; Wofsy, Steven C; Trumbore, Susan E; Martinelli, Luiz Antonio

2004-08-01

Living trees constitute one of the major stocks of carbon in tropical forests. A better understanding of variations in the dynamics and structure of tropical forests is necessary for predicting the potential for these ecosystems to lose or store carbon, and for understanding how they recover from disturbance. Amazonian tropical forests occur over a vast area that encompasses differences in topography, climate, and geologic substrate. We observed large differences in forest structure, biomass, and tree growth rates in permanent plots situated in the eastern (near Santarém, Pará), central (near Manaus, Amazonas) and southwestern (near Rio Branco, Acre) Amazon, which differed in dry season length, as well as other factors. Forests at the two sites experiencing longer dry seasons, near Rio Branco and Santarém, had lower stem frequencies (460 and 466 ha(-1) respectively), less biodiversity (Shannon-Wiener diversity index), and smaller aboveground C stocks (140.6 and 122.1 Mg C ha(-1)) than the Manaus site (626 trees ha(-1), 180.1 Mg C ha(-1)), which had less seasonal variation in rainfall. The forests experiencing longer dry seasons also stored a greater proportion of the total biomass in trees with >50 cm diameter (41-45 vs 30% in Manaus). Rates of annual addition of C to living trees calculated from monthly dendrometer band measurements were 1.9 (Manaus), 2.8 (Santarém), and 2.6 (Rio Branco) Mg C ha(-1) year(-1). At all sites, trees in the 10-30 cm diameter class accounted for the highest proportion of annual growth (38, 55 and 56% in Manaus, Rio Branco and Santarém, respectively). Growth showed marked seasonality, with largest stem diameter increment in the wet season and smallest in the dry season, though this may be confounded by seasonal variation in wood water content. Year-to-year variations in C allocated to stem growth ranged from nearly zero in Rio Branco, to 0.8 Mg C ha(-1) year(-1) in Manaus (40% of annual mean) and 0.9 Mg C ha(-1) year(-1) (33% of annual mean) in Santarém, though this variability showed no significant relation with precipitation among years. Initial estimates of the C balance of live wood including recruitment and mortality as well as growth suggests that live wood biomass is at near steady-state in Manaus, but accumulating at about 1.5 Mg C ha(-1) at the other two sites. The causes of C imbalance in living wood pools in Santarém and Rio Branco sites are unknown, but may be related to previous disturbance at these sites. Based on size distribution and growth rate differences in the three sites, we predict that trees in the Manaus forest have greater mean age (approximately 240 years) than those of the other two forests (approximately 140 years).
QUANTIFYING FOREST ABOVEGROUND CARBON POOLS AND FLUXES USING MULTI-TEMPORAL LIDAR A report on field monitoring, remote sensing MMV, GIS integration, and modeling results for forestry field validation test to quantify aboveground tree biomass and carbon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee Spangler; Lee A. Vierling; Eva K. Stand

2012-04-01

Sound policy recommendations relating to the role of forest management in mitigating atmospheric carbon dioxide (CO{sub 2}) depend upon establishing accurate methodologies for quantifying forest carbon pools for large tracts of land that can be dynamically updated over time. Light Detection and Ranging (LiDAR) remote sensing is a promising technology for achieving accurate estimates of aboveground biomass and thereby carbon pools; however, not much is known about the accuracy of estimating biomass change and carbon flux from repeat LiDAR acquisitions containing different data sampling characteristics. In this study, discrete return airborne LiDAR data was collected in 2003 and 2009 acrossmore » {approx}20,000 hectares (ha) of an actively managed, mixed conifer forest landscape in northern Idaho, USA. Forest inventory plots, established via a random stratified sampling design, were established and sampled in 2003 and 2009. The Random Forest machine learning algorithm was used to establish statistical relationships between inventory data and forest structural metrics derived from the LiDAR acquisitions. Aboveground biomass maps were created for the study area based on statistical relationships developed at the plot level. Over this 6-year period, we found that the mean increase in biomass due to forest growth across the non-harvested portions of the study area was 4.8 metric ton/hectare (Mg/ha). In these non-harvested areas, we found a significant difference in biomass increase among forest successional stages, with a higher biomass increase in mature and old forest compared to stand initiation and young forest. Approximately 20% of the landscape had been disturbed by harvest activities during the six-year time period, representing a biomass loss of >70 Mg/ha in these areas. During the study period, these harvest activities outweighed growth at the landscape scale, resulting in an overall loss in aboveground carbon at this site. The 30-fold increase in sampling density between the 2003 and 2009 did not affect the biomass estimates. Overall, LiDAR data coupled with field reference data offer a powerful method for calculating pools and changes in aboveground carbon in forested systems. The results of our study suggest that multitemporal LiDAR-based approaches are likely to be useful for high quality estimates of aboveground carbon change in conifer forest systems.« less
A remote sensing-based model of tidal marsh aboveground carbon stocks for the conterminous United States

NASA Astrophysics Data System (ADS)

Byrd, Kristin B.; Ballanti, Laurel; Thomas, Nathan; Nguyen, Dung; Holmquist, James R.; Simard, Marc; Windham-Myers, Lisamarie

2018-05-01

Remote sensing based maps of tidal marshes, both of their extents and carbon stocks, have the potential to play a key role in conducting greenhouse gas inventories and implementing climate mitigation policies. Our objective was to generate a single remote sensing model of tidal marsh aboveground biomass and carbon that represents nationally diverse tidal marshes within the conterminous United States (CONUS). We developed the first calibration-grade, national-scale dataset of aboveground tidal marsh biomass, species composition, and aboveground plant carbon content (%C) from six CONUS regions: Cape Cod, MA, Chesapeake Bay, MD, Everglades, FL, Mississippi Delta, LA, San Francisco Bay, CA, and Puget Sound, WA. Using the random forest machine learning algorithm, we tested whether imagery from multiple sensors, Sentinel-1 C-band synthetic aperture radar, Landsat, and the National Agriculture Imagery Program (NAIP), can improve model performance. The final model, driven by six Landsat vegetation indices and with the soil adjusted vegetation index as the most important (n = 409, RMSE = 310 g/m2, 10.3% normalized RMSE), successfully predicted biomass for a range of marsh plant functional types defined by height, leaf angle and growth form. Model results were improved by scaling field-measured biomass calibration data by NAIP-derived 30 m fraction green vegetation. With a mean plant carbon content of 44.1% (n = 1384, 95% C.I. = 43.99%-44.37%), we generated regional 30 m aboveground carbon density maps for estuarine and palustrine emergent tidal marshes as indicated by a modified NOAA Coastal Change Analysis Program map. We applied a multivariate delta method to calculate uncertainties in regional carbon densities and stocks that considered standard error in map area, mean biomass and mean %C. Louisiana palustrine emergent marshes had the highest C density (2.67 ± 0.004 Mg/ha) of all regions, while San Francisco Bay brackish/saline marshes had the highest C density of all estuarine emergent marshes (2.03 ± 0.004 Mg/ha). Estimated C stocks for predefined jurisdictional areas ranged from 1023 ± 39 Mg in the Nisqually National Wildlife Refuge in Washington to 507,761 ± 14,822 Mg in the Terrebonne and St. Mary Parishes in Louisiana. This modeling and data synthesis effort will allow for aboveground C stocks in tidal marshes to be included in the coastal wetland section of the U.S. National Greenhouse Gas Inventory. With the increased availability of free post-processed satellite data, we provide a tractable means of modeling tidal marsh aboveground biomass and carbon at the global extent as well.
Aboveground tree growth varies with belowground carbon allocation in a tropical rainforest environment

Treesearch

J.W. Raich; D.A. Clark; L. Schwendenmann; Tana Wood

2014-01-01

Young secondary forests and plantations in the moist tropics often have rapid rates of biomass accumulation and thus sequester large amounts of carbon. Here, we compare results from mature forest and nearby 15â20 year old tree plantations in lowland Costa Rica to evaluate differences in allocation of carbon to aboveground production and root systems. We found that the...
Mapping aboveground carbon stocks using LiDAR data in Eucalyptus spp. plantations in the state of Sao Paulo, Brazil

Treesearch

Carlos Alberto Silva; Carine Klauberg; Samuel de Padua Chaves e Carvalho; Andrew T. Hudak; e Luiz Carlos Estraviz Rodriguez

2014-01-01

Fast growing plantation forests provide a low-cost means to sequester carbon for greenhouse gas abatement. The aim of this study was to evaluate airborne LiDAR (Light Detection And Ranging) to predict aboveground carbon (AGC) stocks in Eucalyptus spp. plantations. Biometric parameters (tree height (Ht) and diameter at breast height (DBH)) were collected from...

Spatial distribution of forest aboveground biomass estimated from remote sensing and forest inventory data in New England, USA

Treesearch

Daolan Zheng; Linda S. Heath; Mark J. Ducey

2008-01-01

We combined satellite (Landsat 7 and Moderate Resolution Imaging Spectrometer) and U.S. Department of Agriculture forest inventory and analysis (FIA) data to estimate forest aboveground biomass (AGB) across New England, USA. This is practical for large-scale carbon studies and may reduce uncertainty of AGB estimates. We estimate that total regional forest AGB was 1,867...
Estimation of crown biomass of Pinus pinaster stands and shrubland above-ground biomass using forest inventory data, remotely sensed imagery and spatial prediction models

Treesearch

H. Viana; J. Aranha; D. Lopes; Warren B. Cohen

2012-01-01

Spatially crown biomass of Pinus pinaster stands and shrubland above-ground biomass (AGB) estimation was carried-out in a region located in Centre-North Portugal, by means of different approaches including forest inventory data, remotely sensed imagery and spatial prediction models. Two cover types (pine stands and shrubland) were inventoried and...
Modeling loblolly pine aboveground live biomass in a mature pine-hardwood stand: a cautionary tale

Treesearch

D. C. Bragg

2011-01-01

Carbon sequestration in forests is a growing area of interest for researchers and land managers. Calculating the quantity of carbon stored in forest biomass seems to be a straightforward task, but it is highly dependent on the function(s) used to construct the stand. For instance, there are a number of possible equations to predict aboveground live biomass for loblolly...
Loss of aboveground forest biomass and landscape biomass variability in Missouri, US

Treesearch

Brice B. Hanberry; Hong S. He; Stephen R. Shifley

2016-01-01

Disturbance regimes and forests have changed over time in the eastern United States. We examined effects of historical disturbance (circa 1813 to 1850) compared to current disturbance (circa 2004 to 2008) on aboveground, live tree biomass (for trees with diameters â¥13 cm) and landscape variation of biomass in forests of the Ozarks and Plains landscapes in Missouri, USA...
Effects of water table position and plant functional group on plant community, aboveground production, and peat properties in a peatland mesocosm experiment (PEATcosm)

Treesearch

Lynette R. Potvin; Evan S. Kane; Rodney A. Chimner; Randall K. Kolka; Erik A. Lilleskov

2015-01-01

Aims Our objective was to assess the impacts of water table position and plant functional type on peat structure, plant community composition and aboveground plant production. Methods We initiated a full factorial experiment with 2 water table (WT) treatments (high and low) and 3 plant functional groups (PFG: sedge, Ericaceae,...
Quantification of live aboveground forest biomass dynamics with Landsat time-series and field inventory data: A comparison of empirical modeling approaches

Treesearch

Scott L. Powell; Warren B. Cohen; Sean P. Healey; Robert E. Kennedy; Gretchen G. Moisen; Kenneth B. Pierce; Janet L. Ohmann

2010-01-01

Spatially and temporally explicit knowledge of biomass dynamics at broad scales is critical to understanding how forest disturbance and regrowth processes influence carbon dynamics. We modeled live, aboveground tree biomass using Forest Inventory and Analysis (FIA) field data and applied the models to 20+ year time-series of Landsat satellite imagery to...
Using Landsat Time-Series and LiDAR to Inform Aboveground Forest Biomass Baselines in Northern Minnesota, USA

Treesearch

Ram K. Deo; Matthew B. Russell; Grant M. Domke; Christopher W. Woodall; Michael J. Falkowski; Warren B. Cohen

2017-01-01

The publicly accessible archive of Landsat imagery and increasing regional-scale LiDAR acquisitions offer an opportunity to periodically estimate aboveground forest biomass (AGB) from 1990 to the present to alignwith the reporting needs ofNationalGreenhouseGas Inventories (NGHGIs). This study integrated Landsat time-series data, a state-wide LiDAR dataset, and a recent...
Landsat phenological metrics and their relation to aboveground carbon in the Brazilian Savanna.

PubMed

Schwieder, M; Leitão, P J; Pinto, J R R; Teixeira, A M C; Pedroni, F; Sanchez, M; Bustamante, M M; Hostert, P

2018-05-15

The quantification and spatially explicit mapping of carbon stocks in terrestrial ecosystems is important to better understand the global carbon cycle and to monitor and report change processes, especially in the context of international policy mechanisms such as REDD+ or the implementation of Nationally Determined Contributions (NDCs) and the UN Sustainable Development Goals (SDGs). Especially in heterogeneous ecosystems, such as Savannas, accurate carbon quantifications are still lacking, where highly variable vegetation densities occur and a strong seasonality hinders consistent data acquisition. In order to account for these challenges we analyzed the potential of land surface phenological metrics derived from gap-filled 8-day Landsat time series for carbon mapping. We selected three areas located in different subregions in the central Brazil region, which is a prominent example of a Savanna with significant carbon stocks that has been undergoing extensive land cover conversions. Here phenological metrics from the season 2014/2015 were combined with aboveground carbon field samples of cerrado sensu stricto vegetation using Random Forest regression models to map the regional carbon distribution and to analyze the relation between phenological metrics and aboveground carbon. The gap filling approach enabled to accurately approximate the original Landsat ETM+ and OLI EVI values and the subsequent derivation of annual phenological metrics. Random Forest model performances varied between the three study areas with RMSE values of 1.64 t/ha (mean relative RMSE 30%), 2.35 t/ha (46%) and 2.18 t/ha (45%). Comparable relationships between remote sensing based land surface phenological metrics and aboveground carbon were observed in all study areas. Aboveground carbon distributions could be mapped and revealed comprehensible spatial patterns. Phenological metrics were derived from 8-day Landsat time series with a spatial resolution that is sufficient to capture gradual changes in carbon stocks of heterogeneous Savanna ecosystems. These metrics revealed the relationship between aboveground carbon and the phenology of the observed vegetation. Our results suggest that metrics relating to the seasonal minimum and maximum values were the most influential variables and bear potential to improve spatially explicit mapping approaches in heterogeneous ecosystems, where both spatial and temporal resolutions are critical.
Identification of fine scale and landscape scale drivers of urban aboveground carbon stocks using high-resolution modeling and mapping.

PubMed

Mitchell, Matthew G E; Johansen, Kasper; Maron, Martine; McAlpine, Clive A; Wu, Dan; Rhodes, Jonathan R

2018-05-01

Urban areas are sources of land use change and CO 2 emissions that contribute to global climate change. Despite this, assessments of urban vegetation carbon stocks often fail to identify important landscape-scale drivers of variation in urban carbon, especially the potential effects of landscape structure variables at different spatial scales. We combined field measurements with Light Detection And Ranging (LiDAR) data to build high-resolution models of woody plant aboveground carbon across the urban portion of Brisbane, Australia, and then identified landscape scale drivers of these carbon stocks. First, we used LiDAR data to quantify the extent and vertical structure of vegetation across the city at high resolution (5×5m). Next, we paired this data with aboveground carbon measurements at 219 sites to create boosted regression tree models and map aboveground carbon across the city. We then used these maps to determine how spatial variation in land cover/land use and landscape structure affects these carbon stocks. Foliage densities above 5m height, tree canopy height, and the presence of ground openings had the strongest relationships with aboveground carbon. Using these fine-scale relationships, we estimate that 2.2±0.4 TgC are stored aboveground in the urban portion of Brisbane, with mean densities of 32.6±5.8MgCha -1 calculated across the entire urban land area, and 110.9±19.7MgCha -1 calculated within treed areas. Predicted carbon densities within treed areas showed strong positive relationships with the proportion of surrounding tree cover and how clumped that tree cover was at both 1km 2 and 1ha resolutions. Our models predict that even dense urban areas with low tree cover can have high carbon densities at fine scales. We conclude that actions and policies aimed at increasing urban carbon should focus on those areas where urban tree cover is most fragmented. Copyright © 2017 Elsevier B.V. All rights reserved.
Twenty Years of Litter and Root Manipulations: Insights into Multi-Decadal SOM Dynamics and Controls

NASA Astrophysics Data System (ADS)

Wig, J.; Lajtha, K.; Nadelhoffer, K. J.

2012-12-01

Reforestation, reducing deforestation, and sustainable forest management are often recommended by policy makers to mitigate the greenhouse gas contributions of the forestry sector. However, underlying many of these policy recommendations is the assumption that increasing above-ground carbon stocks corresponds to long-term increases in ecosystem carbon stocks, the majority of which is stored in soils. We analyzed soil carbon and nitrogen dynamics in forest soils that had undergone twenty years of continuous manipulations of above- and below-ground organic inputs as part of the Detritus Input and Removal Treatment (DIRT) network. Although we expected that increased C inputs would correspond to significantly elevated C in surface mineral soils, our data suggest that increasing above-ground litter inputs has had a positive priming effect in this soil. Positive priming occurs when increased rates of litter addition to soil lead to disproportionate increases in microbial respiration rates of native soil C, resulting in a net decrease of soil C. Soil respiration rates in a year-long laboratory incubation support this theory: increased above-ground litter inputs led to decreased respiration rates, suggesting a relative deficit of labile organic matter. Removal of below ground inputs, either with or without above-ground litter inputs, also led to decreased respiration in laboratory incubations, demonstrating the importance of fresh root inputs to labile C. Trends in non-hydrolyzable C fractions, a proxy for the more stable C pool, agree with our respiration measurements. Data from sequential density fractionation are consistent with the hypotheses that priming has occurred in response to increased above-ground litter inputs and that root inputs are an important control of the labile C pool. The importance of roots inputs for C stabilization is well documented in the literature, and our hypothesis that increased above-ground litter inputs leads to priming is supported by data from several other DIRT sites. These data indicate there is an important potential loss of ecosystem C due to priming which should be considered when changing organic inputs to the soil, as is the case in some sustainable forestry recommendations.
Progress report on the Happy Jack mine, Which Canyon area, San Juan county, Utah

USGS Publications Warehouse

Trites, Albert F.; Chew, Randall T.

1954-01-01

The Happy Jack mine is in the White Canyon area, San Juan county, Utah. Production is from high-grade uranium deposits in the Shinarump conglomerate of the Triassic age. In this area the Shinarump beds range from about 16 to 40 feet in thickness and the lower part of these beds fills an east-trending channel this is note than 750 feet wide and 10 feet deep. The Shinarump conglomerate consists of beds of coarse- to fine-grained quartzose sandstone, conglomerate, siltstone, and claystone. Carbonized wood is abundant in these beds, and in the field it was classified as mineral charcoal and coal. Intra-Shinarump channels, cross-stratification, current lineation, and slumping and compaction structures have been recognized in the mine. Steeply dipping fractures have dominant trends in four directions -- N 65°W, N 60°E, N 85°E, and due north. Uranium occurs as bedded deposits, as replacement bodies in accumulations of "trash", and as replacements of larger fragments of wood. An "ore shoot" is formed where the three types of uranium deposits occur together; these ore shoots appear to be elongate masses with sharp boundaries. Uranium minerals include uraninite, sooty pitchblende(?), and the sulfate--betazippeite, johannite, and uranopilite. Associated with the uraninite are the sulfide minerals covellite, bornite, chalcopyritw, and pyrite. Galena and sphalerite have been found in close association with uranium minerals. The gaunge minerals include: limonite and hematite present in most of the sandstone beds throughout the deposit, jarosite that impregnates much of the sandstone in the outer parts of the mine workings, gypsum that fills many of the fractures, and barite that impregnates the sandstone in at least one part of the mine. Secondary copper minerals, mainly copper sulfates, occur throughout the mine, but most abundant near the adits in the outermost 30 feet of the workings. The minerals comprising the bulk of the country rock include quartz, feldspar, and clay minerals. The amount of uranium minerals deposited in a sandstone bed is believed to have been determined by the position of the bed in the channel, the permeability of the sandstone in the bed, and the amount of carbonized wood and plant remains within the bed. The beds considered most favorable for uranium deposition contain an abundance of claystone and siltstone both as matrix filling and as fragments and pebbles. Suggested exploration guides from uranium ore bodies include the following: (1) interbedded siltstone lenses, (2) claystone and siltstone cement and pabbles, (3) concentrations of "trash", (4) covelllite and bornite, (5) chalcopyrite, and (6) carbonized wood.
Response of Plant Height, Species Richness and Aboveground Biomass to Flooding Gradient along Vegetation Zones in Floodplain Wetlands, Northeast China.

PubMed

Lou, Yanjing; Pan, Yanwen; Gao, Chuanyu; Jiang, Ming; Lu, Xianguo; Xu, Y Jun

2016-01-01

Flooding regime changes resulting from natural and human activity have been projected to affect wetland plant community structures and functions. It is therefore important to conduct investigations across a range of flooding gradients to assess the impact of flooding depth on wetland vegetation. We conducted this study to identify the pattern of plant height, species richness and aboveground biomass variation along the flooding gradient in floodplain wetlands located in Northeast China. We found that the response of dominant species height to the flooding gradient depends on specific species, i.e., a quadratic response for Carex lasiocarpa, a negative correlation for Calamagrostis angustifolia, and no response for Carex appendiculata. Species richness showed an intermediate effect along the vegetation zone from marsh to wet meadow while aboveground biomass increased. When the communities were analysed separately, only the water table depth had significant impact on species richness for two Carex communities and no variable for C. angustifolia community, while height of dominant species influenced aboveground biomass. When the three above-mentioned communities were grouped together, variations in species richness were mainly determined by community type, water table depth and community mean height, while variations in aboveground biomass were driven by community type and the height of dominant species. These findings indicate that if habitat drying of these herbaceous wetlands in this region continues, then two Carex marshes would be replaced gradually by C. angustifolia wet meadow in the near future. This will lead to a reduction in biodiversity and an increase in productivity and carbon budget. Meanwhile, functional traits must be considered, and should be a focus of attention in future studies on the species diversity and ecosystem function in this region.
Monitoring individual tree-based change with airborne lidar.

PubMed

Duncanson, Laura; Dubayah, Ralph

2018-05-01

Understanding the carbon flux of forests is critical for constraining the global carbon cycle and managing forests to mitigate climate change. Monitoring forest growth and mortality rates is critical to this effort, but has been limited in the past, with estimates relying primarily on field surveys. Advances in remote sensing enable the potential to monitor tree growth and mortality across landscapes. This work presents an approach to measure tree growth and loss using multidate lidar campaigns in a high-biomass forest in California, USA. Individual tree crowns were delineated in 2008 and again in 2013 using a 3D crown segmentation algorithm, with derived heights and crown radii extracted and used to estimate individual tree aboveground biomass. Tree growth, loss, and aboveground biomass were analyzed with respect to tree height and crown radius. Both tree growth and loss rates decrease with increasing tree height, following the expectation that trees slow in growth rate as they age. Additionally, our aboveground biomass analysis suggests that, while the system is a net source of aboveground carbon, these carbon dynamics are governed by size class with the largest sources coming from the loss of a relatively small number of large individuals. This study demonstrates that monitoring individual tree-based growth and loss can be conducted with multidate airborne lidar, but these methods remain relatively immature. Disparities between lidar acquisitions were particularly difficult to overcome and decreased the sample of trees analyzed for growth rate in this study to 21% of the full number of delineated crowns. However, this study illuminates the potential of airborne remote sensing for ecologically meaningful forest monitoring at an individual tree level. As methods continue to improve, airborne multidate lidar will enable a richer understanding of the drivers of tree growth, loss, and aboveground carbon flux.
Lidar-derived estimate and uncertainty of carbon sink in successional phases of woody encroachment

NASA Astrophysics Data System (ADS)

Sankey, Temuulen; Shrestha, Rupesh; Sankey, Joel B.; Hardegree, Stuart; Strand, Eva

2013-07-01

encroachment is a globally occurring phenomenon that contributes to the global carbon sink. The magnitude of this contribution needs to be estimated at regional and local scales to address uncertainties present in the global- and continental-scale estimates, and guide regional policy and management in balancing restoration activities, including removal of woody plants, with greenhouse gas mitigation goals. The objective of this study was to estimate carbon stored in various successional phases of woody encroachment. Using lidar measurements of individual trees, we present high-resolution estimates of aboveground carbon storage in juniper woodlands. Segmentation analysis of lidar point cloud data identified a total of 60,628 juniper tree crowns across four watersheds. Tree heights, canopy cover, and density derived from lidar were strongly correlated with field measurements of 2613 juniper stems measured in 85 plots (30 × 30 m). Aboveground total biomass of individual trees was estimated using a regression model with lidar-derived height and crown area as predictors (Adj. R2 = 0.76, p < 0.001, RMSE = 0.58 kg). The predicted mean aboveground woody carbon storage for the study area was 677 g/m2. Uncertainty in carbon storage estimates was examined with a Monte Carlo approach that addressed major error sources. Ranges predicted with uncertainty analysis in the mean, individual tree, aboveground woody C, and associated standard deviation were 0.35 - 143.6 kg and 0.5 - 1.25 kg, respectively. Later successional phases of woody encroachment had, on average, twice the aboveground carbon relative to earlier phases. Woody encroachment might be more successfully managed and balanced with carbon storage goals by identifying priority areas in earlier phases of encroachment where intensive treatments are most effective.
An experimental test of the EICA hypothesis in multiple ranges: invasive populations outperform those from the native range independent of insect herbivore suppression

PubMed Central

DeWalt, Saara J.; Zou, Jianwen; Rogers, William E.

2017-01-01

Abstract The success of invasive plants may reflect environmental differences in their native and introduced ranges including both abiotic and biotic conditions, such as release from aboveground herbivory. However, in response to these novel conditions, plants from invasive populations may have higher growth rates and lower defence levels compared with those in the native range. This may contribute to their success in the introduced range but perhaps not in the native range. Here, we grew 1000 Triadica sebifera plants from 14 native and introduced populations in seven common gardens with unmanaged background vegetation for three growing seasons in three geographic venues that varied in T. sebifera status and insect herbivore communities: Texas—T. sebifera is invasive, low levels of generalist herbivory; Hawaii—T. sebifera introduced but not invasive, high levels of generalist herbivory from exotic herbivores; China—native range, both generalist and specialist herbivores. We suppressed aboveground insects with insecticide on half the plants. Aboveground damage in the first growing season was lowest in Texas and insecticide sprays reduced damage in China. At the end of the first growing season, plants were tallest on an average in China and shortest in Hawaii. However, height in later years and mass were the highest on average in Texas and the lowest in Hawaii. However, there was large variation in damage and plant performance among gardens within venues. Our results suggest that more rapid aboveground growth rates contribute to T. sebifera’s success in both the invasive and native ranges independent of aboveground herbivory. However, strong variation among sites indicates that T. sebifera plants from invasive populations only have a strong advantage in a subset of sites in Texas. PMID:28039113
An experimental test of the EICA Hypothesis in multiple ranges: invasive populations outperform those from the native range independent of insect herbivore suppression.

PubMed

Siemann, Evan; DeWalt, Saara J; Zou, Jianwen; Rogers, William E

2016-12-30

The success of invasive plants may reflect environmental differences in their native and introduced ranges including both abiotic and biotic conditions, such as release from aboveground herbivory. However, in response to these novel conditions, plants from invasive populations may have higher growth rates and lower defense levels compared to those in the native range. This may contribute to their success in the introduced range but perhaps not in the native range. Here, we grew 1000 Triadica sebifera plants from 14 native and introduced populations in seven common gardens with unmanaged background vegetation for three growing seasons in three geographic venues that varied in T. sebifera status and insect herbivore communities: Texas -T. sebifera is invasive, low levels of generalist herbivory; Hawaii - T. sebifera introduced but not invasive, high levels of generalist herbivory from exotic herbivores; China - native range, both generalist and specialist herbivores. We suppressed aboveground insects with insecticide on half the plants. Aboveground damage in the first growing season was lowest in Texas and insecticide sprays reduced damage in China. At the end of the first growing season, plants were tallest on average in China and shortest in Hawaii. However, height in later years and mass were highest on average in Texas and lowest in Hawaii. However, there was large variation in damage and plant performance among gardens within venues. Our results suggest that more rapid aboveground growth rates contribute to T. sebifera's success in both the invasive and native ranges independent of aboveground herbivory. However, strong variation among sites indicates that T. sebifera plants from invasive populations only have a strong advantage in a subset of sites in Texas. Published by Oxford University Press on behalf of the Annals of Botany Company.
Aboveground carbon in Quebec forests: stock quantification at the provincial scale and assessment of temperature, precipitation and edaphic properties effects on the potential stand-level stocking.

PubMed

Duchesne, Louis; Houle, Daniel; Ouimet, Rock; Lambert, Marie-Claude; Logan, Travis

2016-01-01

Biological carbon sequestration by forest ecosystems plays an important role in the net balance of greenhouse gases, acting as a carbon sink for anthropogenic CO2 emissions. Nevertheless, relatively little is known about the abiotic environmental factors (including climate) that control carbon storage in temperate and boreal forests and consequently, about their potential response to climate changes. From a set of more than 94,000 forest inventory plots and a large set of spatial data on forest attributes interpreted from aerial photographs, we constructed a fine-resolution map (∼375 m) of the current carbon stock in aboveground live biomass in the 435,000 km(2) of managed forests in Quebec, Canada. Our analysis resulted in an area-weighted average aboveground carbon stock for productive forestland of 37.6 Mg ha(-1), which is lower than commonly reported values for similar environment. Models capable of predicting the influence of mean annual temperature, annual precipitation, and soil physical environment on maximum stand-level aboveground carbon stock (MSAC) were developed. These models were then used to project the future MSAC in response to climate change. Our results indicate that the MSAC was significantly related to both mean annual temperature and precipitation, or to the interaction of these variables, and suggest that Quebec's managed forests MSAC may increase by 20% by 2041-2070 in response to climate change. Along with changes in climate, the natural disturbance regime and forest management practices will nevertheless largely drive future carbon stock at the landscape scale. Overall, our results allow accurate accounting of carbon stock in aboveground live tree biomass of Quebec's forests, and provide a better understanding of possible feedbacks between climate change and carbon storage in temperate and boreal forests.
Response of Plant Height, Species Richness and Aboveground Biomass to Flooding Gradient along Vegetation Zones in Floodplain Wetlands, Northeast China

PubMed Central

Lou, Yanjing; Pan, Yanwen; Gao, Chuanyu; Jiang, Ming; Lu, Xianguo; Xu, Y. Jun

2016-01-01

Flooding regime changes resulting from natural and human activity have been projected to affect wetland plant community structures and functions. It is therefore important to conduct investigations across a range of flooding gradients to assess the impact of flooding depth on wetland vegetation. We conducted this study to identify the pattern of plant height, species richness and aboveground biomass variation along the flooding gradient in floodplain wetlands located in Northeast China. We found that the response of dominant species height to the flooding gradient depends on specific species, i.e., a quadratic response for Carex lasiocarpa, a negative correlation for Calamagrostis angustifolia, and no response for Carex appendiculata. Species richness showed an intermediate effect along the vegetation zone from marsh to wet meadow while aboveground biomass increased. When the communities were analysed separately, only the water table depth had significant impact on species richness for two Carex communities and no variable for C. angustifolia community, while height of dominant species influenced aboveground biomass. When the three above-mentioned communities were grouped together, variations in species richness were mainly determined by community type, water table depth and community mean height, while variations in aboveground biomass were driven by community type and the height of dominant species. These findings indicate that if habitat drying of these herbaceous wetlands in this region continues, then two Carex marshes would be replaced gradually by C. angustifolia wet meadow in the near future. This will lead to a reduction in biodiversity and an increase in productivity and carbon budget. Meanwhile, functional traits must be considered, and should be a focus of attention in future studies on the species diversity and ecosystem function in this region. PMID:27097325
Effects of 10-year management regimes on the soil seed bank in saline-alkaline grassland.

PubMed

Ma, Hongyuan; Yang, Haoyu; Liang, Zhengwei; Ooi, Mark K J

2015-01-01

Management regimes for vegetation restoration of degraded grasslands can significantly affect the process of ecological succession. However, few studies have focused on variation in the soil seed bank during vegetation restoration under different management regimes, especially in saline-alkaline grassland habitats. Our aim was to provide insights into the ecological effects of grassland management regimes on soil seed bank composition and vegetation establishment in mown, fenced, transplanted and natural grassland sites, all dominated by the perennial rhizomatous grass Leymus chinensis. We studied species composition and diversity in both the soil seed bank and aboveground vegetation in differently managed grasslands in Northeast China. An NMDS (nonmetric multidimensional scaling) was used to evaluate the relationship between species composition, soil seed banks, aboveground vegetation and soil properties. Fenced and mown grassland sites had high density and species richness in both the soil seed bank and aboveground vegetation. The Transplanted treatment exhibited the highest vegetation growth and seed production of the target species L. chinensis. Seeds of L. chinensis in the soil occurred only in transplanted and natural grassland. Based on the NMDS analysis, the number of species in both the soil seed bank and aboveground vegetation were significantly related to soil Na+, Cl-, RSC (residual sodium carbonate), alkalinity, ESP (exchangeable sodium percentage) and AP (available phosphorus). Soil seed bank composition and diversity in the saline-alkaline grassland were significantly affected by the management regimes implemented, and were also significantly related to the aboveground vegetation and several soil properties. Based on vegetative growth, reproductive output and maintenance of soil seed bank, the transplanting was identified as the most effective method for relatively rapid restoration of the target species L. chinensis. This approach could be beneficial for the restoration of dominant species in a wide range of degraded grassland ecosystems.
Leaching of arsenic, copper and chromium from thermally treated soil.

PubMed

Kumpiene, Jurate; Nordmark, Désirée; Hamberg, Roger; Carabante, Ivan; Simanavičienė, Rūta; Aksamitauskas, Vladislovas Česlovas

2016-12-01

Thermal treatment, if properly performed, is an effective way of destroying organic compounds in contaminated soil, while impact on co-present inorganic contaminants varies depending on the element. Leaching of trace elements in thermally treated soil can be altered by co-combusting different types of materials. This study aimed at assessing changes in mobility of As, Cr and Cu in thermally treated soil as affected by addition of industrial by-products prior to soil combustion. Contaminated soil was mixed with either waste of gypsum boards, a steel processing residue (Fe 3 O 4 ), fly ash from wood and coal combustion or a steel abrasive (96.5% Fe 0 ). The mixes and unamended soil were thermally treated at 800 °C and divided into a fine fraction <0.125 mm and a coarse fraction >0.125 mm to simulate particle separation occurring in thermal treatment plants. The impact of the treatment on element behaviour was assessed by a batch leaching test, X-ray absorption spectroscopy and dispersive X-ray spectrometry. The results suggest that thermal treatment is highly unfavourable for As contaminated soils as it increased both the As leaching in the fine particle size fraction and the mass of the fines (up to 92%). Soil amendment with Fe-containing compounds prior to the thermal treatment reduced As leaching to the levels acceptable for hazardous waste landfills, but only in the coarse fraction, which does not justify the usefulness of such treatment. Among the amendments used, gypsum most effectively reduced leaching of Cr and Cu in thermally treated soil and could be recommended for soils that do not contain As. Fly ash was the least effective amendment as it increased leaching of both Cr and As in majority of samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Polyphenols in the woody roots of Norway spruce and European beech reduce TTC.

PubMed

Richter, Anika K; Frossard, Emmanuel; Brunner, Ivano

2007-01-01

A common method to determine the vitality of fine root tissue is the measurement of respiratory activity with triphenyltetrazolium chloride (TTC). The colorless TTC is reduced to the red-colored triphenyl formazan (TF) as a result of the dehydrogenase activity of the mitochondrial respiratory chain. However, measurements with woody fine roots of adult Norway spruce and European beech trees showed that dead control roots had a high potential to react with TTC. High reactivity was found in boiled fine roots and the bark of coarse roots, but not in the boiled wood of coarse roots. By sequential extraction of dried and ground adult Norway spruce fine roots, reactivity with TTC was reduced by about 75% (water extraction), 93% (water/methanol extraction) and 94% (water/acetone extraction). The water extract reacted with TTC in the same way as polyphenols such as lignin, catechin and epicatechin. Boiling did not affect the extent to which fine roots of adult trees reduced TTC, whereas it greatly reduced TTC reduction by seedling roots. Application of the TTC test to roots of spruce seedlings subjected to increasing drought showed a progressive decrease in TTC reduction. The decrease in TTC reduction was paralleled by a reduction in O(2) consumption, thus supporting the conclusion that for roots with a low polyphenol content the TTC test provides a valid assessment of tissue vitality. Our results suggest, however, that the TTC test should not be applied to the fine roots of adult trees because of their high content of polyphenolic compounds whose reaction with TTC masks changes in TTC reduction due to changes in the respiratory capacity of the tissue.
Source identification and seasonal variation of polycyclic aromatic hydrocarbons associated with atmospheric fine and coarse particles in the Metropolitan Area of Porto Alegre, RS, Brazil

NASA Astrophysics Data System (ADS)

Teixeira, Elba Calesso; Agudelo-Castañeda, Dayana M.; Fachel, Jandyra Maria Guimarães; Leal, Karen Alam; Garcia, Karine de Oliveira; Wiegand, Flavio

2012-11-01

The purpose of the present study was to evaluate the polycyclic aromatic hydrocarbons (PAHs) in fine (PM2.5) and coarse particles (PM2.5-10) in an urban and industrial area in the Metropolitan Area of Porto Alegre (MAPA), Brazil. Sixteen U.S. Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) were measured. Filters containing ambient air particulate were extracted with dichloromethane using Soxhlet. Extracts were later analyzed, for determining PAH concentrations, using a gaseous chromatograph coupled with a mass spectrometer (GC-MS). The polycyclic aromatic hydrocarbons (PAHs) were more concentrated in PM2.5 with an average of 70% of total PAHs in the MAPA. The target PAH apportionment among the main emission sources was carried out by diagnostic PAH concentration ratios, and principal component analysis (PCA). PAHs with higher molecular weight showed higher percentages in the fine particles in the MAPA. Based on the diagnostic ratios and PCA analysis, it may be concluded that the major contribution of PAHs was from vehicular sources (diesel and gasoline), especially in the PM2.5 fraction, as well as coal and wood burning. The winter/summer ratio in the PM2.5 and PM2.5-10 fractions in the MAPA was 3.1 and 1.8, respectively, revealing the seasonal variation of PAHs in the two fractions. The estimated toxicity equivalent factor (TEF), used to assess the contribution of the carcinogenic potency, confirms a significant presence of the moderately active carcinogenic PAHs BaP and DahA in the samples collected in the MAPA.
Fire severity alters the distribution of pyrogenic carbon stocks across ecosystem pools in a Californian mixed-conifer forest

NASA Astrophysics Data System (ADS)

Maestrini, Bernardo; Alvey, Erin C.; Hurteau, Matthew D.; Safford, Hugh; Miesel, Jessica R.

2017-09-01

Pyrogenic carbon (PyC) is hypothesized to play an important role in the carbon (C) cycle due to its resistance to decomposition; however, much uncertainty still exists regarding the stocks of PyC that persist on-site after the initial erosion in postfire forests. Therefore, understanding how fire characteristics influence PyC stocks is vital, particularly in the context of California forests for which an increase of high-severity fires is predicted over the next decades. We measured forest C and persistent PyC stocks in areas burned by low-to-moderate and high-severity fire, as well as in adjacent unburned areas in a California mixed-conifer forest, 2 to 3 years after wildfire. We measured C and PyC stocks in the following compartments: standing trees, downed wood, forest floor, and mineral soil (0-5 cm), and we identified PyC using the weak nitric acid digestion method. We found that the total stock of PyC did not differ among fire severity classes (overall mean 248 ± 30 g C m-2); however, fire severity influenced the distribution of PyC in the individual compartments. Areas burned by high-severity fire had 2.5 times more PyC stocked in the coarse woody debris (p < 0.05), 3.3 times more PyC stocked in standing trees (p < 0.05), and a lower PyC stock in the forest floor (-22%, p < 0.05) compared to low-to-moderate fire severity areas. These results have important implications for the permanence time of PyC, which is putatively higher in standing trees and coarse woody debris compared to the forest floor, where it is susceptible to rapid losses through erosion.
Fine Root Dynamics and Forest Production Across a Calcium Gradient in Northern Hardwood and Conifer Ecosystems

Treesearch

Byung Bae Park; Ruth D. Yanai; Timothy J. Fahey; Scott W. Bailey; Thomas G. Siccama; James B. Shanley; Natalie L. Cleavitt

2008-01-01

Losses of soil base cations due to acid rain have been implicated in declines of red spruce and sugar maple in the northeastern USA. We studied fine root and aboveground biomass and production in five northern hardwood and three conifer stands differing in soil Ca status at Sleepers River, VT; Hubbard Brook, NH; and Cone Pond, NH. Neither aboveground biomass and...
Non-pulp utilization of above-ground biomass of mixed-species forests of small trees

Treesearch

P. Koch

1982-01-01

This soulution propose to rehabilitate annually- by clear felling, site preparation, and planting- 25,000 acres of level to rolling land averaging about490 cubic feet per acre of stemwood in small hardwood trees 5 inches in diameter at breast height (dbh) and larger, and of many species, plus all equal volume of above-ground biomass in stembark and tops, and in trees...
Stand restoration burning in oak-pine forests in the southern Applachians: effects on aboveground biomass and carbon and nitrogen cycling

Treesearch

Robert M. Hubbard; James M. Vose; Barton D. Clinton; Katherine J. Elliott; Jennifer D. Knoepp

2004-01-01

Understory prescribed burning is being suggested as a viable management tool for restoring degraded oakâpine forest communities in the southern Appalachians yet information is lacking on how this will affect ecosystem processes. Our objectives in this study were to evaluate the watershed scale effects of understory burning on total aboveground biomass, and the carbon...
Validation databases for simulation models: aboveground biomass and net primary productive, (NPP) estimation using eastwide FIA data

Treesearch

Jennifer C. Jenkins; Richard A. Birdsey

2000-01-01

As interest grows in the role of forest growth in the carbon cycle, and as simulation models are applied to predict future forest productivity at large spatial scales, the need for reliable and field-based data for evaluation of model estimates is clear. We created estimates of potential forest biomass and annual aboveground production for the Chesapeake Bay watershed...
Methods and equations for estimating aboveground volume, biomass, and carbon for trees in the U.S. forest inventory, 2010

Treesearch

Christopher W. Woodall; Linda S. Heath; Grant M. Domke; Michael C. Nichols

2011-01-01

The U.S. Forest Service, Forest Inventory and Analysis (FIA) program uses numerous models and associated coefficients to estimate aboveground volume, biomass, and carbon for live and standing dead trees for most tree species in forests of the United States. The tree attribute models are coupled with FIA's national inventory of sampled trees to produce estimates of...
Future forest aboveground carbon dynamics in the central United States: the importance of forest demographic processes

Treesearch

Wenchi Jin; Hong S. He; Frank R. Thompson; Wen J. Wang; Jacob S. Fraser; Stephen R. Shifley; Brice B. Hanberry; William D. Dijak

2017-01-01

The Central Hardwood Forest (CHF) in the United States is currently a major carbon sink, there are uncertainties in how long the current carbon sink will persist and if the CHF will eventually become a carbon source. We used a multi-model ensemble to investigate aboveground carbon density of the CHF from 2010 to 2300 under current climate. Simulations were done using...
Spatial relationships among species, above-ground biomass, N, and P in degraded grasslands in Ordus Plateau, northwestern China

Treesearch

X. Cheng; S. An; J. chen; B. Li; Y. Liu; S. Liu

2007-01-01

We chose five communities, representing a mild to severe gradient of grassland desertification in a semi-arid area of Ordos Plateau, northwestern China, to explore the spatial relationships among plant species, above-ground biomass (AGB), and plant nutrients (N and P). Community 1 (Cl) was dominated by Stipa bungeana; community 2 (C2) by a mix of S...
Shifts in Aboveground and Forest Floor Carbon and Nitrogen Pools After Felling and Burning in the Southern Appalachians

Treesearch

Barton D. Clinton; James M. Vose; Wayne T. Swank

1996-01-01

Changes in aboveground and forest floor mass, carbon (C), and nitrogen (N) pools were quantified on three sites in the southern Appalachians 2 yr after felling and burning. Before felling and burning, stands were characterized by sparse overstories and dense Kalmia latifolia L. understories. Two years after burning, foliar C and N pools had reached 25% and 29% of...
Assessment of forest management influences on total live aboveground tree biomass in William B Bankhead National Forest, Alabama

Treesearch

Callie Schweitzer; Dawn Lemke; Wubishet Tadesse; Yong Wang

2015-01-01

Forests contain a large amount of carbon (C) stored as tree biomass (above and below ground), detritus, and soil organic material. The aboveground tree biomass is the most rapid change component in this forest C pool. Thus, management of forest resources can influence the net C exchange with the atmosphere by changing the amount of C stored, particularly in landscapes...
Evaluating Site-Specific and Generic Spatial Models of Aboveground Forest Biomass Based on Landsat Time-Series and LiDAR Strip Samples in the Eastern USA

Treesearch

Ram Deo; Matthew Russell; Grant Domke; Hans-Erik Andersen; Warren Cohen; Christopher Woodall

2017-01-01

Large-area assessment of aboveground tree biomass (AGB) to inform regional or national forest monitoring programs can be efficiently carried out by combining remotely sensed data and field sample measurements through a generic statistical model, in contrast to site-specific models. We integrated forest inventory plot data with spatial predictors from Landsat time-...
Observations and modeling of aboveground tree carbon stocks and fluxes following a bark beetle outbreak in the western United States

Treesearch

Eric M. Pfeifer; Jeffrey A. Hicke; Arjan J.H. Meddens

2011-01-01

Bark beetle epidemics result in tree mortality across millions of hectares in North America. However, few studies have quantified impacts on carbon (C) cycling. In this study, we quantified the immediate response and subsequent trajectories of stand-level aboveground tree C stocks and fluxes using field measurements and modeling for a location in central Idaho, USA...
Lidar-based estimates of aboveground biomass in the continental US and Mexico using ground, airborne, and satellite observations

Treesearch

Ross Nelson; Hank Margolis; Paul Montesano; Guoqing Sun; Bruce Cook; Larry Corp; Hans-Erik Andersen; Ben deJong; Fernando Paz Pellat; Thaddeus Fickel; Jobriath Kauffman; Stephen Prisley

2017-01-01

Existing national forest inventory plots, an airborne lidar scanning (ALS) system, and a space profiling lidar system (ICESat-GLAS) are used to generate circa 2005 estimates of total aboveground dry biomass (AGB) in forest strata, by state, in the continental United States (CONUS) and Mexico. The airborne lidar is used to link ground observations of AGB to space lidar...
Effects of thinning on aboveground carbon sequestration by a 45-year-old eastern white pine plantation: A case study

Treesearch

W. Henry McNab

2012-01-01

Aboveground carbon sequestration by a 45-year-old plantation of eastern white pines was determined in response to thinning to three levels of residual basal area: (1) Control (no thinning), (2) light thinning to 120 feet2/acre and (3) heavy thinning to 80 feet2/acre. After 11 years carbon stocks were lowest on the heavily...
Proven Alternatives for Aboveground Treatment of Arsenic in Groundwater

DTIC Science & Technology

2002-10-01

Contaminant of Concern by Mediaa Media Number of Sites Groundwater 380 Soil 372 Sediment 154 Surface Water 86 Debris 77 Sludge 45 Solid Waste 30 Leachate ...issue paper does not address three technologies that have been used to treat water containing arsenic: • Biological treatment • Phytoremediation ...arsenic in water, and no aboveground treatments of groundwater conducted at full scale were found. Phytoremediation and electrokinetics are not
Modeling Aboveground Biomass in Hulunber Grassland Ecosystem by Using Unmanned Aerial Vehicle Discrete Lidar

PubMed Central

Wang, Dongliang; Xin, Xiaoping; Shao, Quanqin; Brolly, Matthew; Zhu, Zhiliang; Chen, Jin

2017-01-01

Accurate canopy structure datasets, including canopy height and fractional cover, are required to monitor aboveground biomass as well as to provide validation data for satellite remote sensing products. In this study, the ability of an unmanned aerial vehicle (UAV) discrete light detection and ranging (lidar) was investigated for modeling both the canopy height and fractional cover in Hulunber grassland ecosystem. The extracted mean canopy height, maximum canopy height, and fractional cover were used to estimate the aboveground biomass. The influences of flight height on lidar estimates were also analyzed. The main findings are: (1) the lidar-derived mean canopy height is the most reasonable predictor of aboveground biomass (R2 = 0.340, root-mean-square error (RMSE) = 81.89 g·m−2, and relative error of 14.1%). The improvement of multiple regressions to the R2 and RMSE values is unobvious when adding fractional cover in the regression since the correlation between mean canopy height and fractional cover is high; (2) Flight height has a pronounced effect on the derived fractional cover and details of the lidar data, but the effect is insignificant on the derived canopy height when the flight height is within the range (<100 m). These findings are helpful for modeling stable regressions to estimate grassland biomass using lidar returns. PMID:28106819
Modeling Aboveground Biomass in Hulunber Grassland Ecosystem by Using Unmanned Aerial Vehicle Discrete Lidar.

PubMed

Wang, Dongliang; Xin, Xiaoping; Shao, Quanqin; Brolly, Matthew; Zhu, Zhiliang; Chen, Jin

2017-01-19

Accurate canopy structure datasets, including canopy height and fractional cover, are required to monitor aboveground biomass as well as to provide validation data for satellite remote sensing products. In this study, the ability of an unmanned aerial vehicle (UAV) discrete light detection and ranging (lidar) was investigated for modeling both the canopy height and fractional cover in Hulunber grassland ecosystem. The extracted mean canopy height, maximum canopy height, and fractional cover were used to estimate the aboveground biomass. The influences of flight height on lidar estimates were also analyzed. The main findings are: (1) the lidar-derived mean canopy height is the most reasonable predictor of aboveground biomass ( R ² = 0.340, root-mean-square error (RMSE) = 81.89 g·m -2 , and relative error of 14.1%). The improvement of multiple regressions to the R ² and RMSE values is unobvious when adding fractional cover in the regression since the correlation between mean canopy height and fractional cover is high; (2) Flight height has a pronounced effect on the derived fractional cover and details of the lidar data, but the effect is insignificant on the derived canopy height when the flight height is within the range (<100 m). These findings are helpful for modeling stable regressions to estimate grassland biomass using lidar returns.
Species richness of arbuscular mycorrhizal fungi: associations with grassland plant richness and biomass.

PubMed

Hiiesalu, Inga; Pärtel, Meelis; Davison, John; Gerhold, Pille; Metsis, Madis; Moora, Mari; Öpik, Maarja; Vasar, Martti; Zobel, Martin; Wilson, Scott D

2014-07-01

Although experiments show a positive association between vascular plant and arbuscular mycorrhizal fungal (AMF) species richness, evidence from natural ecosystems is scarce. Furthermore, there is little knowledge about how AMF richness varies with belowground plant richness and biomass. We examined relationships among AMF richness, above- and belowground plant richness, and plant root and shoot biomass in a native North American grassland. Root-colonizing AMF richness and belowground plant richness were detected from the same bulk root samples by 454-sequencing of the AMF SSU rRNA and plant trnL genes. In total we detected 63 AMF taxa. Plant richness was 1.5 times greater belowground than aboveground. AMF richness was significantly positively correlated with plant species richness, and more strongly with below- than aboveground plant richness. Belowground plant richness was positively correlated with belowground plant biomass and total plant biomass, whereas aboveground plant richness was positively correlated only with belowground plant biomass. By contrast, AMF richness was negatively correlated with belowground and total plant biomass. Our results indicate that AMF richness and plant belowground richness are more strongly related with each other and with plant community biomass than with the plant aboveground richness measures that have been almost exclusively considered to date. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

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