Soil organic matter composition and quality across fire severity gradients in coniferous and deciduous forests of the southern boreal region

NASA Astrophysics Data System (ADS)

Miesel, Jessica R.; Hockaday, William C.; Kolka, Randall K.; Townsend, Philip A.

2015-06-01

Recent patterns of prolonged regional drought in southern boreal forests of the Great Lakes region, USA, suggest that the ecological effects of disturbance by wildfire may become increasingly severe. Losses of forest soil organic matter (SOM) during fire can limit soil nutrient availability and forest regeneration. These processes are also influenced by the composition of postfire SOM. We sampled the forest floor layer (i.e., full organic horizon) and 0-10 cm mineral soil from stands dominated by coniferous (Pinus banksiana Lamb.) or deciduous (Populus tremuloides Michx.) species 1-2 months after the 2011 Pagami Creek wildfire in northern Minnesota. We used solid-state 13C NMR to characterize SOM composition across a gradient of fire severity in both forest cover types. SOM composition was affected by fire, even when no statistically significant losses of total C stocks were evident. The most pronounced differences in SOM composition between burned and unburned reference areas occurred in the forest floor for both cover types. Carbohydrate stocks in forest floor and mineral horizons decreased with severity level in both cover types, whereas pyrogenic C stocks increased with severity in the coniferous forest floor and decreased in only the highest severity level in the deciduous forest floor. Loss of carbohydrate and lignin pools contributed to a decreased SOM stability index and increased decomposition index. Our results suggest that increases in fire severity expected to occur under future climate scenarios may lead to changes in SOM composition and dynamics with consequences for postfire forest recovery and C uptake.

Changes in soil fertility following prescribed burning on Coastal Plain pine sites

Treesearch

William H. McKee

1982-01-01

Soil and forest floor samples were collected from four prescribed burning studies in the Atlantic and Gulf Coastal Plains. The surface textures of soils ranged from sands to silt loams and the drainage classes from well to poorly drained. Burning treatments had been in force from 8 to 65 years. Reduction of the forest floor and its chemical constituents was related to...

Chemistry of burning the forest floor during the FROSTFIRE experimental burn, interior Alaska, 1999.

Treesearch

J.W. Harden; J.C. Neff; D.V. Sandberg; M.R. Turetsky; R. Ottmar; G. Gleixner; T.L. Fries; K.L. Manies

2004-01-01

Wildfires represent one of the most common disturbances in boreal regions, and have the potential to reduce C, N, and Hg stocks in soils while contributing to atmospheric emissions. Organic soil layers of the forest floor were sampled before and after the FROSTFIRE experimental burn in interior Alaska, and were analyzed for bulk density, major and trace elements, and...

Seasonal Variations in Ash Content of Some Michigan Forest Floor Fuels

Treesearch

Robert M. Loomis

1982-01-01

Samples from the forest floor litter layer were collected seasonally from under medium to fully stocked larger sapling to sawtimber stands in Lower Michigan to study seasonal ash content changes. The total ash and silica-free ash content of tree foliage in the upper part of the litter layer differed little from season to season. Differences in ash content due to...

Forest floor temperature and relative humidity following timber harvesting in southern New England, USA

Treesearch

Robert T. Brooks; Thomas D. Kyker-Snowman

2008-01-01

Forest amphibians, especially salamanders, prefer forests with shaded, cool, and moist forest floors. Timber harvesting opens the forest canopy and exposes the forest floor to direct sunlight, which can increase forest floor temperatures and reduce soil moisture. These microclimatic changes can potentially degrade the harvested stand for amphibian habitat or affect...

Soil-seed bank survival in forests of the southern United States

Treesearch

James S. Meadows; Frank T. Bonner; James D. Haywood

2006-01-01

We evaluated the longevity of seeds of 12 common woody species buried in fresh condition in the forest floor at three forest locations in Mississippi and Louisiana. Seed samples of each species were retrieved annually for 5 years from each location. Germination and tetrazolium chloride staining tests were conducted on the samples to determine germinative capacity. When...

Small mammals in managed, naturally young, and old-growth forests.

Treesearch

A.B. Carey; M.L. Johnson

1995-01-01

Forest managers in the Pacific Northwest are faced with new challenges of providing for all wildlife in managed forests. Our objective was to elucidate the factors governing the composition and biomass of forest floor mammal communities that are amenable to management. We sampled small mammal communities in forests of various management histories on the Olympic...

Forest nutrient and carbon pools at Walker Branch watershed: changes during a 21-year period

Treesearch

Carl C. Trettin; D.W. Johnson; D.E. Todd

1999-01-01

A 21-yr perspective on changes in nutrient and C pools on undisturbed upland forest sites is provided. Plots originally representing four cover types have been sampled three times. On each plot, forest biomass, forest floor, and soil, to a depth of 60 cm, were measured, sampled, and analyzed for Ca, Mg, C, N, and P. Exchangeable soil Ca and Mg have declined in most...

Factors Affecting Salamander Density and Distribution within Four Forest Types in Southern Appalachian Mountains

Treesearch

Craig A. Harper; David C. Guynn

1999-01-01

We used a terrestrial vacuum to sample known area plots in order to obtain density estimates of salamanders and their primary prey, invertebrates of the forest floor. We sampled leaf litter and measured various vegetative and topographic parameters within four forest types (oak-pine, oak-hickory, mixed mesophytic and northern hardwoods) and three age classes (0-12,13-...

Wildfire and forest disease interaction lead to greater loss of soil nutrients and carbon.

PubMed

Cobb, Richard C; Meentemeyer, Ross K; Rizzo, David M

2016-09-01

Fire and forest disease have significant ecological impacts, but the interactions of these two disturbances are rarely studied. We measured soil C, N, Ca, P, and pH in forests of the Big Sur region of California impacted by the exotic pathogen Phytophthora ramorum, cause of sudden oak death, and the 2008 Basin wildfire complex. In Big Sur, overstory tree mortality following P. ramorum invasion has been extensive in redwood and mixed evergreen forests, where the pathogen kills true oaks and tanoak (Notholithocarpus densiflorus). Sampling was conducted across a full-factorial combination of disease/no disease and burned/unburned conditions in both forest types. Forest floor organic matter and associated nutrients were greater in unburned redwood compared to unburned mixed evergreen forests. Post-fire element pools were similar between forest types, but lower in burned-invaded compared to burned-uninvaded plots. We found evidence disease-generated fuels led to increased loss of forest floor C, N, Ca, and P. The same effects were associated with lower %C and higher PO4-P in the mineral soil. Fire-disease interactions were linear functions of pre-fire host mortality which was similar between the forest types. Our analysis suggests that these effects increased forest floor C loss by as much as 24.4 and 21.3 % in redwood and mixed evergreen forests, respectively, with similar maximum losses for the other forest floor elements. Accumulation of sudden oak death generated fuels has potential to increase fire-related loss of soil nutrients at the region-scale of this disease and similar patterns are likely in other forests, where fire and disease overlap.

Patterns of biomass and carbon distribution across a chronosequence of Chinese pine (Pinus tabulaeformis) forests.

PubMed

Zhao, Jinlong; Kang, Fengfeng; Wang, Luoxin; Yu, Xiaowen; Zhao, Weihong; Song, Xiaoshuai; Zhang, Yanlei; Chen, Feng; Sun, Yu; He, Tengfei; Han, Hairong

2014-01-01

Patterns of biomass and carbon (C) storage distribution across Chinese pine (Pinus tabulaeformis) natural secondary forests are poorly documented. The objectives of this study were to examine the biomass and C pools of the major ecosystem components in a replicated age sequence of P. tabulaeformis secondary forest stands in Northern China. Within each stand, biomass of above- and belowground tree, understory (shrub and herb), and forest floor were determined from plot-level investigation and destructive sampling. Allometric equations using the diameter at breast height (DBH) were developed to quantify plant biomass. C stocks in the tree and understory biomass, forest floor, and mineral soil (0-100 cm) were estimated by analyzing the C concentration of each component. The results showed that the tree biomass of P. tabulaeformis stands was ranged from 123.8 Mg·ha-1 for the young stand to 344.8 Mg·ha-1 for the mature stand. The understory biomass ranged from 1.8 Mg·ha-1 in the middle-aged stand to 3.5 Mg·ha-1 in the young stand. Forest floor biomass increased steady with stand age, ranging from 14.9 to 23.0 Mg·ha-1. The highest mean C concentration across the chronosequence was found in tree branch while the lowest mean C concentration was found in forest floor. The observed C stock of the aboveground tree, shrub, forest floor, and mineral soil increased with increasing stand age, whereas the herb C stock showed a decreasing trend with a sigmoid pattern. The C stock of forest ecosystem in young, middle-aged, immature, and mature stands were 178.1, 236.3, 297.7, and 359.8 Mg C ha-1, respectively, greater than those under similar aged P. tabulaeformis forests in China. These results are likely to be integrated into further forest management plans and generalized in other contexts to evaluate C stocks at the regional scale.

Patterns of Biomass and Carbon Distribution across a Chronosequence of Chinese Pine (Pinus tabulaeformis) Forests

PubMed Central

Wang, Luoxin; Yu, Xiaowen; Zhao, Weihong; Song, Xiaoshuai; Zhang, Yanlei; Chen, Feng; Sun, Yu; He, Tengfei; Han, Hairong

2014-01-01

Patterns of biomass and carbon (C) storage distribution across Chinese pine (Pinus tabulaeformis) natural secondary forests are poorly documented. The objectives of this study were to examine the biomass and C pools of the major ecosystem components in a replicated age sequence of P. tabulaeformis secondary forest stands in Northern China. Within each stand, biomass of above- and belowground tree, understory (shrub and herb), and forest floor were determined from plot-level investigation and destructive sampling. Allometric equations using the diameter at breast height (DBH) were developed to quantify plant biomass. C stocks in the tree and understory biomass, forest floor, and mineral soil (0–100 cm) were estimated by analyzing the C concentration of each component. The results showed that the tree biomass of P. tabulaeformis stands was ranged from 123.8 Mg·ha–1 for the young stand to 344.8 Mg·ha–1 for the mature stand. The understory biomass ranged from 1.8 Mg·ha–1 in the middle-aged stand to 3.5 Mg·ha–1 in the young stand. Forest floor biomass increased steady with stand age, ranging from 14.9 to 23.0 Mg·ha–1. The highest mean C concentration across the chronosequence was found in tree branch while the lowest mean C concentration was found in forest floor. The observed C stock of the aboveground tree, shrub, forest floor, and mineral soil increased with increasing stand age, whereas the herb C stock showed a decreasing trend with a sigmoid pattern. The C stock of forest ecosystem in young, middle-aged, immature, and mature stands were 178.1, 236.3, 297.7, and 359.8 Mg C ha–1, respectively, greater than those under similar aged P. tabulaeformis forests in China. These results are likely to be integrated into further forest management plans and generalized in other contexts to evaluate C stocks at the regional scale. PMID:24736660

Biotic and abiotic factors regulating forest floor CO2 flux across a range of forest age classes in the southern Appalachians

Treesearch

James M. Vose; Paul V. Bolstad

2007-01-01

We measured forest floor CO2 flux in three age classes of forest in the southern Appalachians: 20-year-old, 85-year-old, and old-growth. Our objectives were to quantify differences in forest floor CO2 flux among age classes, and determine the relative importance of abiotic and biotic driving variables. Forest floor CO

Production, Stocks and Characteristics of Wildfire Charcoal in Canadian Boreal Forests; a Preliminary Synthesis

NASA Astrophysics Data System (ADS)

Preston, C. M.; Simard, M.

2016-12-01

Crowning wildfires are a major driver of carbon stocks and ecosystem development in Canadian boreal forests, but there is insufficient information to incorporate pyrogenic carbon (PyC) into models and management strategies. Data comparison is challenging because of varied experimental design, and studies are often limited to forest floor; nonetheless we have attempted a synthesis limited to visually determined PyC, hereafter designated "charcoal". Sources include our study of amounts, depth distribution (forest floor plus variable amounts of upper mineral soil) and chemical properties of charcoal (>2 mm) from a fire chronosequence in the Abitibi region of Quebec (51 jack pine (Pinus banksiana) and black spruce (Picea mariana) sites, 24 to 2355 years since fire). Complete charcoal production of 7900 kg/ha (forest floor, down wood, standing stems) was determined from an experimental crownfire in jack pine near Fort Providence (NWT) in 2012. Published data were assembled mainly from boreal conifer studies, but using more disparate sources for production, plus laboratory charring studies. Typical findings include high spatial variability, with depth distributions often showing a maximum around the organic-mineral interface. Stocks varied widely (up to ca. 5500 kg/ha), with little initial discernable trend with time, but were much lower in the few older sites (>700y). Total C and N were widely scattered for younger samples, but older samples were mainly 500-600 g C/kg with C/N values around 100. Similarly, carbon-13 NMR spectra show wider variation in young samples, with the oldest samples being highly aromatic. These initial variations are consistent with field reports of highly variable temperatures and duration of charring and many laboratory studies. As a starting point, it may be possibly suggested that a boreal crowning wildfire might produce some 5000-10000 kg/ha of charred material of 550-650 g C/kg, with half to two-thirds on forest floor and down wood and most of the rest on standing stems. Our synthesis mainly highlights future research needs, including more measurements on stems and down wood and chemical analysis of the black carbon component of charcoal.

A model of forest floor carbon mass for United States forest types

Treesearch

James E. Smith; Linda S. Heath

2002-01-01

Includes a large set of published values of forest floor mass and develop large-scale estimates of carbon mass according to region and forest type. Estimates of average forest floor carbon mass per hectare of forest applied to a 1997 summary forest inventory, sum to 4.5 Gt carbon stored in forests of the 48 contiguous United States.

Lead sequestration and species redistribution during soil organic matter decomposition

USGS Publications Warehouse

Schroth, A.W.; Bostick, B.C.; Kaste, J.M.; Friedland, A.J.

2008-01-01

The turnover of soil organic matter (SOM) maintains a dynamic chemical environment in the forest floor that can impact metal speciation on relatively short timescales. Here we measure the speciation of Pb in controlled and natural organic (O) soil horizons to quantify changes in metal partitioning during SOM decomposition in different forest litters. We provide a link between the sequestration of pollutant Pb in O-horizons, estimated by forest floor Pb inventories, and speciation using synchrotron-based X-ray fluorescence and X-ray absorption spectroscopy. When Pb was introduced to fresh forest Oi samples, it adsorbed primarily to SOM surfaces, but as decomposition progressed over two years in controlled experiments, up to 60% of the Pb was redistributed to pedogenic birnessite and ferrihydrite surfaces. In addition, a significant fraction of pollutant Pb in natural soil profiles was associated with similar mineral phases (???20-35%) and SOM (???65-80%). Conifer forests have at least 2-fold higher Pb burdens in the forest floor relative to deciduous forests due to more efficient atmospheric scavenging and slower organic matter turnover. We demonstrate that pedogenic minerals play an important role in surface soil Pb sequestration, particularly in deciduous forests, and should be considered in any assessment of pollutant Pb mobility. ?? 2008 American Chemical Society.

Long-term changes in forest floor processes in southern Appalachian forests

Treesearch

Jennifer D. Knoepp; Barbara C. Reynolds; D.A. Crossley; Wayne T. Swank

2005-01-01

Soil nutrient concentrations decreased in an aggrading southern Appalachian forest over a 20-year period. Construction of nutrient budgets showed significant nutrient sequestration aboveground including increased forest floor mass. We hypothesized that the changes in forest floor mass resulted from decreased litter decomposition rates because of decreased litter...

Effects of the amount and composition of the forest floor on emergence and early establishment of loblolly pine seedlings

Treesearch

Michael G. Shelton

1995-01-01

Five forest floor weights (0, 10, 20, 30, and 40 MgJha), three forest floor compositions (pine, pine-hardwood, and hardwood), and two seed placements (forest floor and soil surface) were tested in a three-factorial. split-plot design with four incomplete, randomized blocks. The experiment was conducted in a nursery setting and used wooden frames to define 0.145-m

Assessment of soil calcium status in red spruce forests in the northeastern United States

USGS Publications Warehouse

Lawrence, G.B.; David, M.B.; Bailey, S.W.; Shortle, W.C.

1997-01-01

Long-term changes in concentrations of available Ca in soils of red spruce forests have been documented, but remaining questions about the magnitude and regional extent of these changes have precluded an assessment of the current and future status of soil Ca. To address this problem, soil samples were collected in 1992-93 from 12 sites in New York, Vermont, New Hampshire, and Maine to provide additional data necessary to synthesize all available research results on soil Ca in red spruce forests. Sites were chosen to encompass the range of environmental conditions experienced by red spruce. Concentrations of exchangeable Ca ranged from 2.13 to 21.6 cmol(c) kg-1 in the Oa horizon, and from 0.11 to 0.68 cmol(c) kg-1 in the upper 10 cm of the B horizon. These measurements expanded the range of exchangeable Ca reported in the literature for both horizons in northeastern red spruce forests. Exchangeable Ca was the largest Ca fraction in the forest floor at most sites (92% of acid-extractable Ca), but mineral Ca was the largest fraction at the three sites that also had the highest mineral-matter concentrations. The primary factor causing variability in Ca concentrations among sites was the mineralogy of parent material, but exchangeable concentrations in the B horizon of all sites were probably reduced by acidic deposition. Because the majority of Ca in the forest floor is in a readily leachable form, and Ca inputs to the forest floor from the mineral soil and atmospheric deposition have been decreasing in recent decades, the previously documented decreases in Ca concentrations in the forest floor over previous decades may extend into the future.

Response of Forest Floor Microarthropods to a Forest Regeneration Burn at Wine Spring Watershed (Southern Appalachians)

Treesearch

D.A Crossley; Randi A. Hansen; Karen L. Lamoncha

1997-01-01

We sampled microarthropods in litter and soil of the Wine Spring watershed on April 2,1995 before the watershed was burned, again on May. 9, 1995 immediately following burning> and two years later on June 9,1997.Pre-burn samples revealed a high abundance of mites (Arachnida: Atari) and collembolans. (Insecta: Collembola). Oriibatid (Atari: Oribatei) mites were...

Vertical distribution of radiocesium in coniferous forest soil after the Fukushima nuclear power plant accident.

PubMed

Teramage, Mengistu T; Onda, Yuichi; Patin, Jeremy; Kato, Hiroaki; Gomi, Takashi; Nam, Sooyoun

2014-11-01

This study deals with the description of the vertical distribution of radiocaesium ((137)Cs and (134)Cs) in a representative coniferous forest soil, investigated 10 months after the Fukushima radioactive fallout. During soil sampling, the forest floor components (understory plants, litter (Ol-) and fermented layers (Of)) were collected and treated separately. The results indicate that radiocesium is concentrated in the forest floor, and high radiocesium transfer factor observed in the undergrowth plants (3.3). This made the forest floor an active exchanging interphase for radiocesium. The raw organic layer (Ol + Of) holds 52% (5.3 kBq m(-2)) of the Fukushima-derived and 25% (0.7 kBq m(-2)) of the pre-Fukushima (137)Cs at the time of the soil sampling. Including the pre-Fukushima (137)Cs, 99% of the total soil inventory was in the upper 10 cm, in which the organic matter (OM) content was greater than 10%, suggesting the subsequent distribution most likely depends on the OM turnover. However, the small fraction of the Fukushima-derived (137)Cs at a depth of 16 cm is most likely due to the infiltration of radiocesium-circumscribed rainwater during the fallout before that selective adsorption prevails and reduces the migration of soluble (137)Cs. The values of the depth distribution parameters revealed that the distribution of the Fukushima-derived (137)Cs was somewhat rapid. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Characteristics of floor litter and soil arthropod community in different types ot subtropical forest in Ailao Mountain of Yunnan, Southwest China].

PubMed

Yang, Zhao; Yang, Xiao-Dong

2011-11-01

By using line transect method, an investigation was conducted on the floor litter and soil arthropod community in a mid mountain wet evergreen broad-leaved forest, a mossy dwarf forest, and a Populus bonatii forest in Ailao Mountain of Yunnan in April (dry and hot season), June (rainy season), and December (dry and cold season), 2005. In both dry and rainy seasons, the existing floor litter mass, C storage, and C/N ratio in the three forests all increased in the order of mossy dwarf forest > P. bonatii forest > evergreen broad-leaved forest, but the N storage had less difference. In the floor litter layer of the forests, Acari and Collembola were the dominant groups of soil arthropod community, while Diptera larvae, Coleoptera, ants, and Homoptera were the common groups. The Sorenson coefficients of soil arthropod community in the three forests were extremely great. No significant differences were observed in the soil arthropod density (ind x m(-2)) in the floor litter layer among the three forests, but the relative density (ind x g(-1)) of soil arthropods was higher in the evergreen broad-leaved forest and P. bonatii forest than in the mossy dwarf forest. In the three forests, the density of soil arthropods was significantly higher in dry season than in rainy season, but the Shannon diversity index had less difference. There were significant positive correlations between the existing floor litter mass and the individual density (ind x m(-2)) and dominant groups of soil arthropod communities in dry and hot season (April), but negative correlations between the existing floor litter mass and the relative density (ind x g(-1)) of soil arthropod communities and Acari in dry and cold season (December). The individual densities of Collembola and Coleoptera also had positive correlations with the N storage of the existing floor litter mass in the three forests. It was considered that the floor litter and the development of soil arthropod community in the litter layer of the subtropical forests in Ailao Mountain had a close relation with the vegetation structure of the forests, and the individual density and the diversity of the soil arthropod community were controlled by the floor litter, whereas the environmental factors such as temperature and moisture in the forests also had obvious effects on the seasonal dynamics of the individual density of the soil arthropods.

Using hyperspectral imagery to estimate forest floor consumption from wildfire in boreal forests of Alaska, USA

Treesearch

Sarah A. Lewis; Andrew T. Hudak; Roger D. Ottmar; Peter R. Robichaud; Leigh B. Lentile; Sharon M. Hood; James B. Cronan; Penny Morgan

2011-01-01

Wildfire is a major forest disturbance in interior Alaska that can both directly and indirectly alter ecological processes. We used a combination of pre- and post-fire forest floor depths and post-fire ground cover assessments measured in the field, and high-resolution airborne hyperspectral imagery, to map forest floor conditions after the 2004 Taylor Complex in...

Manganese and Mn/Ca ratios in soil and vegetation in forests across the northeastern US: Insights on spatial Mn enrichment.

PubMed

Richardson, J B

2017-03-01

Manganese (Mn) cycling in the Critical Zone is important because of its role as an essential nutrient and potential toxicity to plants and organisms. Quantifying Mn enrichment in terrestrial environments has been limited since Mn is monoisotopic. However, elemental ratios of Mn/Ca ratios may be used to determine spatial Mn enrichment and in aboveground and belowground pools. The objectives of this study were to quantify the spatial variation in Mn concentrations and Mn/Ca ratios in foliage, bolewood, forest floor, and mineral soil horizons across the northeastern United States and compare Mn/Ca ratios to estimate enrichment. Forest floor and mineral soil samples were collected from 26 study sites across the northeastern United States and analyzed by strong acid digestion. Foliage and bolewood was collected from 12 of the 26 sites and analyzed for total Mn and Ca. Our results show forest floor and mineral soil horizon Mn concentrations and Mn/Ca ratios were higher at Pennsylvania and New York sites than New Hampshire and Vermont sites. Using a modified isotope equation, enrichment factors (EF) for Mn/Ca ratios were calculated to be ~3.6 in the forest floor, upper and lower mineral soil horizons at sites in New York and Pennsylvania compared to reference sites in New Hampshire and Vermont. Foliar and bolewood Mn concentrations also decreased from Pennsylvania towards New Hampshire. Moreover, foliar and bolewood Mn concentrations were strongly correlated to forest floor, upper, and lower mineral soil Mn concentrations. It was hypothesized that internal cycling (uptake, throughfall, and litterfall) of Mn controls retention of enriched Mn in forests. Geologic influences from a lithologic gradient and soil pH gradient could also influence Mn enrichment in addition to Mn pollution. Ratios of Mn/Ca and other elemental ratios hold promise as geochemical tracers but require further development. Copyright © 2016 Elsevier B.V. All rights reserved.

Longevity of black cherry seed in the forest floor

Treesearch

G. W. Wendel

1972-01-01

Observations made on the Fernow Experimental Forest in West Virginia indicate that some black cherry seeds remain viable in the forest floor over three winters. On the average fewer than 10 percent of the seeds stored in the forest floor germinated the first spring, about 50 percent germinated the second spring, and 25 percent germinated the third spring.

Response of Northwest Douglas-fir stands to urea: correlations with forest soil properties.

Treesearch

C.E. Peterson; P.J. Ryan; S.P. Gessel

1984-01-01

Replicated forest floor and surface soil (0–15 cm) samples were obtained from control plots at 160 field installations to western Washington and Oregon. Six year growth responses of thinned and unthinned Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] in stallations treated with 0, 224, and 448 kg of urea-N ha-1 were correlated with 18 forest...

The distribution of nitrogen and phosphorus in forest floor layers of oak-hickory forests of varying productivity

Treesearch

Karyn S. Rodkey; Donald J. Kaczmarek; Phillip E. Pope

1995-01-01

The forest floor plays a major role in the storage and recycling of nutrients which, in turn, are important in maintaining the growth and productivity of forest ecosystems. The development of forest floor organic layers as influenced by litter quality and site quality is unclear. Previous studies in this lab have shown that the size and distribution of available...

Forest floor fuels in red and jack pine stands

Treesearch

James K. Brown

1966-01-01

An investigation to determine the quantity and density of forest floor fuels in red pine (Pinus resinosa Ait.) and jack pine (Pinus banksiana Lamb.) stands was conducted on National Forests in Michigan and Minnesota. The study was designed to answer three questions: How much fuel per acre exits in individual layers of the forest floor? How reliably can weight of...

First direct landscape-scale measurement of tropical rain forest Leaf Area Index, a key driver of global primary productivity

Treesearch

David B. Clark; Paulo C. Olivas; Steven F. Oberbauer; Deborah A. Clark; Michael G. Ryan

2008-01-01

Leaf Area Index (leaf area per unit ground area, LAI) is a key driver of forest productivity but has never previously been measured directly at the landscape scale in tropical rain forest (TRF). We used a modular tower and stratified random sampling to harvest all foliage from forest floor to canopy top in 55 vertical transects (4.6 m2) across 500 ha of old growth in...

Vertical Structure of Phyllosphere Fungal Communities in a Tropical Forest in Thailand Uncovered by High-Throughput Sequencing.

PubMed

Izuno, Ayako; Kanzaki, Mamoru; Artchawakom, Taksin; Wachrinrat, Chongrak; Isagi, Yuji

2016-01-01

Phyllosphere fungi harbor a tremendous species diversity and play important ecological roles. However, little is known about their distribution patterns within forest ecosystems. We examined how species diversity and community composition of phyllosphere fungi change along a vertical structure in a tropical forest in Thailand. Fungal communities in 144 leaf samples from 19 vertical layers (1.28-34.4 m above ground) of 73 plant individuals (27 species) were investigated by metabarcoding analysis using Ion Torrent sequencing. In total, 1,524 fungal operational taxonomic units (OTUs) were detected among 890,710 reads obtained from the 144 leaf samples. Taxonomically diverse fungi belonging to as many as 24 orders of Ascomycota and 21 orders of Basidiomycota were detected, most of which inhabited limited parts of the lowest layers closest to the forest floor. Species diversity of phyllosphere fungi was the highest in the lowest layers closest to the forest floor, decreased with increasing height, and lowest in the canopy; 742 and 55 fungal OTUs were detected at the lowest and highest layer, respectively. On the layers close to the forest floor, phyllosphere fungal communities were mainly composed of low frequency OTUs and largely differentiated among plant individuals. Conversely, in the canopy, fungal communities consisted of similar OTUs across plant individuals, and as many as 86.1%-92.7% of the OTUs found in the canopy (≥22 m above ground) were also distributed in the lower layers. Overall, our study showed the variability of phyllosphere fungal communities along the vertical gradient of plant vegetation and environmental conditions, suggesting the significance of biotic and abiotic variation for the species diversity of phyllosphere fungi.

Properties of dissolved and total organic matter in throughfall, stemflow and forest floor leachate of central European forests

NASA Astrophysics Data System (ADS)

Bischoff, S.; Schwarz, M. T.; Siemens, J.; Thieme, L.; Wilcke, W.; Michalzik, B.

2015-05-01

We present the first investigation of the composition of dissolved organic matter (DOM) compared to total organic matter (TOM, consisting of DOM, < 0.45 μm and particulate organic matter 0.45 μm < POM < 500 μm) in throughfall, stemflow and forest floor leachate of common beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) H. Karst.) forests using solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. We hypothesized that the composition and properties of organic matter (OM) in forest ecosystem water samples differ between DOM and TOM and between the two tree species. The 13C NMR results, derived from 21 samples, point to pronounced differences in the composition of DOM and TOM in throughfall solution at the beech sites, with TOM exhibiting higher relative intensities for the alkyl C region, which represents aliphatic C from less decomposed organic material compared to DOM. Furthermore, TOM shows lower intensities for lignin-derived and aromatic C of the aryl C region resulting in lower aromaticity indices and a diminished degree of humification. Across the ecosystem compartments, differences in the structural composition of DOM and TOM under beech lessened in the following order: throughfall > stemflow ≈ forest floor leachate. In contrast to the broadleaved sites, differences between DOM and TOM in throughfall solution under spruce were less pronounced and spectra were, overall, dominated by the alkyl C region, representing aliphatic C. Explanations of the reported results might be substantiated in differences in tree species-specific structural effects, leaching characteristics or differences in the microbial community of the tree species' phyllosphere and cortisphere. However, the fact that throughfall DOM under beech showed the highest intensities of recalcitrant aromatic and phenolic C among all samples analysed likely points to a high allelopathic potential of beech trees negatively affecting other organisms and hence ecosystem processes and functions.

Changes in Organic Matter And Nutrients in Forest Floor After Applying Several Reproductive Cutting Methods in Shortleaf Pine-Hardwood Stands

Treesearch

Hal O. Liechty; Michael G. Shelton

2004-01-01

Abstract - This study was initiated to determine the effects of various regeneration cutting methods on forest floor mass and nutrient content in shortleaf pine-hardwood communities in the Ouachita and Ozark National Forests. Clearcutting generally altered forest floor concentrations of N, P, and S as well as loss on ignition by increasing the amount...

Effect of chronic nitrogen additions on soil nitrogen fractions in red spruce stands

USGS Publications Warehouse

David, M.B.; Cupples, A.M.; Lawrence, G.B.; Shi, G.; Vogt, K.; Wargo, P.M.

1998-01-01

The responses of temperate and boreal forest ecosystems to increased nitrogen (N) inputs have been varied, and the responses of soil N pools have been difficult to measure. In this study, fractions and pool sizes of N were determined in the forest floor of red spruce stands at four sites in the northeastern U.S. to evaluate the effect of increased N inputs on forest floor N. Two of the stands received 100 kg N ha-1 yr-1 for three years, one stand received 34 kg N ha-1 yr-1 for six years, and the remaining stand received only ambient N inputs. No differences in total N content or N fractions were measured in samples of the Oie and Oa horizons between treated and control plots in the three sites that received N amendments. The predominant N fraction in these samples was amino acid N (31-45 % of total N), followed by hydrolyzable unidentified N (16-31% of total N), acid- soluble N (18-22 % of total N), and NH4/+-N (9-13 % of total N). Rates of atmospheric deposition varied greatly among the four stands. Ammonium N and amino acid N concentrations in the Oie horizon were positively related to wet N deposition, with respective r2 values of 0.92 and 0.94 (n = 4, p < 0.05). These relationships were somewhat stronger than that observed between atmospheric wet N deposition and total N content of the forest floor, suggesting that these pools retain atmospherically deposited N. The NH4/+- N pool may represent atmospherically deposited N that is incorporated into organic matter, whereas the amino acid N pool could result from microbial immobilization of atmospheric N inputs. The response of forest floor N pools to applications of N may be masked, possibly by the large soil N pool, which has been increased by the long-term input of N from atmospheric deposition, thereby overwhelming the short-term treatments.

Forest Floor Characteristics in Southwestern Wisconsin

Treesearch

M. Dean Knighton

1970-01-01

Percent slope, aspect, topographic position, and crown closure were found to have no significant influence on forest floor depth in southwestern Wisconsin. However, a significant decrease in forest floor depth and an increase in soil compaction were found on currently grazed slopes. Yet when grazing is stopped recovery is apperently quick with no permanent damage....

Viability of forest floor and canopy seed banks in Pinus contorta var. latifolia (Pinaceae) forests after a mountain pine beetle outbreak.

PubMed

Teste, François P; Lieffers, Victor J; Landhäusser, Simon M

2011-04-01

Seed banks are important for the natural regeneration of many forest species. Most of the seed bank of serotinous lodgepole pine is found in the canopy, but after an outbreak of mountain pine beetle (MPB), a considerable forest-floor seed bank develops through the falling of canopy cones. After large-scale mortality of pine stands from MPB, however, the viability of seeds in both the canopy and the forest-floor cone bank is uncertain. We sampled cones in five stands 3 yr after MPB (3y-MPB); five stands 6 yr after MPB (6y-MPB); and 10 stands 9 yr after MPB (9y-MPB), in central British Columbia, Canada. Seeds were extracted and viability tested using germination techniques. Forest-floor cones had seed with high germination capacity (GC): 82% for embedded (partly buried) closed cones vs. 45% for buried partly open cones. For canopy cones, GC steeply declined about 15 yr after cone maturation and by 25 yr, GC was 50%, compared with 98% in the first year. In the 3y- and 6y-MPB stands, seeds from cones that were 7 to 9 yr old had similar GC on dead and living trees; however, seeds from the dead trees had lower vigor than seeds from living trees. We demonstrate for the first time that a serotinous pine can form a viable soil seed bank by cone burial, which may facilitate natural regeneration if a secondary disturbance occurs. Seeds contained in 15-yr-old cones showed a steep decline in viability, which could limit regeneration if there is a long delay before a secondary disturbance.

Longevity of Black Cherry, Wild Grape, and Sassafras Seed in the Forest Floor

Treesearch

G.W. Wendel

1977-01-01

The results of this study show that (1) black cherry seed remains viable in the forest floor for 3 years, with a small amount of seed germinating after 4 or 5 years; (2) sassafras seed remains viable for 6 years in the forest floor, and (3) some wild grape seed retains its viability for at least 8 years. These results are important to the forest manager in setting up...

Forest structure and downed woody debris in boreal, temperate, and tropical forest fragments.

PubMed

Gould, William A; González, Grizelle; Hudak, Andrew T; Hollingsworth, Teresa Nettleton; Hollingsworth, Jamie

2008-12-01

Forest fragmentation affects the heterogeneity of accumulated fuels by increasing the diversity of forest types and by increasing forest edges. This heterogeneity has implications in how we manage fuels, fire, and forests. Understanding the relative importance of fragmentation on woody biomass within a single climatic regime, and along climatic gradients, will improve our ability to manage forest fuels and predict fire behavior. In this study we assessed forest fuel characteristics in stands of differing moisture, i.e., dry and moist forests, structure, i.e., open canopy (typically younger) vs. closed canopy (typically older) stands, and size, i.e., small (10-14 ha), medium (33 to 60 ha), and large (100-240 ha) along a climatic gradient of boreal, temperate, and tropical forests. We measured duff, litter, fine and coarse woody debris, standing dead, and live biomass in a series of plots along a transect from outside the forest edge to the fragment interior. The goal was to determine how forest structure and fuel characteristics varied along this transect and whether this variation differed with temperature, moisture, structure, and fragment size. We found nonlinear relationships of coarse woody debris, fine woody debris, standing dead and live tree biomass with mean annual median temperature. Biomass for these variables was greatest in temperate sites. Forest floor fuels (duff and litter) had a linear relationship with temperature and biomass was greatest in boreal sites. In a five-way multivariate analysis of variance we found that temperature, moisture, and age/structure had significant effects on forest floor fuels, downed woody debris, and live tree biomass. Fragment size had an effect on forest floor fuels and live tree biomass. Distance from forest edge had significant effects for only a few subgroups sampled. With some exceptions edges were not distinguishable from interiors in terms of fuels.

Jack Pine and Aspen Forest Floors in Northeastern Minnesota

Treesearch

Robert M. Loomis

1977-01-01

Characteristics of upland forest floors under mature jack pine and aspen in northeastern Minnesota were investigated. These fuel measurements were needed as inputs for fire behavior prediction models -- useful for fire management decisions. The forest floor weight averaged 33,955 kg/ha and depth averaged 7.1 cm. Bulk density averaged 17 kg/m3 for the L (litter)...

Interactions with successional stage and nutrient status determines the life-form-specific effects of increased soil temperature on boreal forest floor vegetation.

PubMed

Hedwall, Per-Ola; Skoglund, Jerry; Linder, Sune

2015-02-01

The boreal forest is one of the largest terrestrial biomes and plays a key role for the global carbon balance and climate. The forest floor vegetation has a strong influence on the carbon and nitrogen cycles of the forests and is sensitive to changes in temperature conditions and nutrient availability. Additionally, the effects of climate warming on forest floor vegetation have been suggested to be moderated by the tree layer. Data on the effects of soil warming on forest floor vegetation from the boreal forest are, however, very scarce. We studied the effects on the forest floor vegetation in a long-term (18 years) soil warming and fertilization experiment in a Norway spruce stand in northern Sweden. During the first 9 years, warming favored early successional species such as grasses and forbs at the expense of dwarf shrubs and bryophytes in unfertilized stands, while the effects were smaller after fertilization. Hence, warming led to significant changes in species composition and an increase in species richness in the open canopy nutrient limited forest. After another 9 years of warming and increasing tree canopy closure, most of the initial effects had ceased, indicating an interaction between forest succession and warming. The only remaining effect of warming was on the abundance of bryophytes, which contrary to the initial phase was strongly favored by warming. We propose that the suggested moderating effects of the tree layer are specific to plant life-form and conclude that the successional phase of the forest may have a considerable impact on the effects of climate change on forest floor vegetation and its feedback effects on the carbon and nitrogen cycles, and thus on the climate.

Interactions with successional stage and nutrient status determines the life-form-specific effects of increased soil temperature on boreal forest floor vegetation

PubMed Central

Hedwall, Per-Ola; Skoglund, Jerry; Linder, Sune

2015-01-01

The boreal forest is one of the largest terrestrial biomes and plays a key role for the global carbon balance and climate. The forest floor vegetation has a strong influence on the carbon and nitrogen cycles of the forests and is sensitive to changes in temperature conditions and nutrient availability. Additionally, the effects of climate warming on forest floor vegetation have been suggested to be moderated by the tree layer. Data on the effects of soil warming on forest floor vegetation from the boreal forest are, however, very scarce. We studied the effects on the forest floor vegetation in a long-term (18 years) soil warming and fertilization experiment in a Norway spruce stand in northern Sweden. During the first 9 years, warming favored early successional species such as grasses and forbs at the expense of dwarf shrubs and bryophytes in unfertilized stands, while the effects were smaller after fertilization. Hence, warming led to significant changes in species composition and an increase in species richness in the open canopy nutrient limited forest. After another 9 years of warming and increasing tree canopy closure, most of the initial effects had ceased, indicating an interaction between forest succession and warming. The only remaining effect of warming was on the abundance of bryophytes, which contrary to the initial phase was strongly favored by warming. We propose that the suggested moderating effects of the tree layer are specific to plant life-form and conclude that the successional phase of the forest may have a considerable impact on the effects of climate change on forest floor vegetation and its feedback effects on the carbon and nitrogen cycles, and thus on the climate. PMID:25750720

Molecular analysis of fungal communities and laccase genes in decomposing litter reveals differences among forest types but no impact of nitrogen deposition

USGS Publications Warehouse

Blackwood, C.B.; Waldrop, M.P.; Zak, D.R.; Sinsabaugh, R. L.

2007-01-01

The fungal community of the forest floor was examined as the cause of previously reported increases in soil organic matter due to experimental N deposition in ecosystems producing predominantly high-lignin litter, and the opposite response in ecosystems producing low-lignin litter. The mechanism proposed to explain this phenomenon was that white-rot basidiomycetes are more important in the degradation of high-lignin litter than of low-lignin litter, and that their activity is suppressed by N deposition. We found that forest floor mass in the low-lignin sugar-maple dominated system decreased in October due to experimental N deposition, whereas forest floor mass of high-lignin oak-dominated ecosystems was unaffected by N deposition. Increased relative abundance of basidiomycetes in high-lignin forest floor was confirmed by denaturing gradient gel electrophoresis (DGGE) and sequencing. Abundance of basidiomycete laccase genes, encoding an enzyme used by white-rot basidiomycetes in the degradation of lignin, was 5-10 times greater in high-lignin forest floor than in low-lignin forest floor. While the differences between the fungal communities in different ecosystems were consistent with the proposed mechanism, no significant effects of N deposition were detected on DGGE profiles, laccase gene abundance, laccase length heterogeneity profiles, or phenol oxidase activity. Our observations indicate that the previously detected accumulation of soil organic matter in the high-lignin system may be driven by effects of N deposition on organisms in the mineral soil, rather than on organisms residing in the forest floor. However, studies of in situ gene expression and temporal and spatial variability within forest floor communities will be necessary to further relate the ecosystem dynamics of organic carbon to microbial communities and atmospheric N deposition. ?? 2007 The Authors; Journal compilation ?? 2007 Society for Applied Microbiology and Blackwell Publishing Ltd.

Carbon stocks of three secondary coniferous forests along an altitudinal gradient on Loess Plateau in inland China

PubMed Central

Liu, Ning; Nan, Hongwei

2018-01-01

Natural forests in inland China are generally distributed in montane area and secondary due to a semi-arid climate and past anthropogenic disturbances. However, quantification of carbon (C) stock in these forests and the role of altitude in determining C storage and its partition among ecosystem components are unclear. We sampled 54 stands of three secondary coniferous forests (Larix principis-rupprechtii (LP) forest, Picea meyerii (PM) forest and Pinus tabulaeformis (PT) forest) on Loess Plateau in an altitudinal range of 1200-2700m a.s.l. C stocks of tree layer, shrub layer, herb layer, coarse wood debris, forest floor and soil were estimated. We found these forests had relatively high total C stocks. Driven by both higher vegetation and soil C stocks, total C stocks of LP and PM forests in the high altitudinal range were 375.0 and 368.4 t C ha-1 respectively, significantly higher than that of PT forest in the low altitudinal range (230.2 t C ha-1). In addition, understory shrubs accounted for about 20% of total biomass in PT forest. The proportions of vegetation to total C stock were similar among in the three forests (below 45%), so were the proportions of soil C stock (over 54%). Necromass C stocks were also similar among these forests, but their proportions to total C stock were significantly lower in LP and PM forests (1.4% and 1.6%) than in PT forest (3.0%). Across forest types, vegetation biomass and soil C stock simultaneously increased with increasing altitude, causing fairly unchanged C partitioning among ecosystem components along the altitudinal gradient. Soil C stock also increased with altitude in LP and PT forests. Forest floor necromass decreased with increasing altitude across the three forests. Our results suggest the important role of the altitudinal gradient in C sequestration and floor necromass of these three forests in terms of alleviated water conditions and in soil C storage of LP and PM forests in terms of temperature change. PMID:29723254

Distribution of parquet flooring during 1969

Treesearch

William C. Miller; William C. Miller

1972-01-01

This is the third in a series of papers dealing with the residential and commercial hardwood flooring industry. The first two paper are: PHYSICAL DISTRIBUTIOONF OAK STRIP FLOORING IN 1969 (U.S.D.A. Forest Serv. Res. Paper NE-207) and DISTRIBUTION OF MAPLE STRIP FLOORING IN 1969. (U.S.D.A. Forest Serv. Res. Paper NE-215).

Changes in conifer and deciduous forest foliar and forest floor chemistry and basal area tree growth across a nitrogen (N) deposition gradient in the northeastern US

Treesearch

Johnny L. Boggs; Steven G. McNulty; Linda H. Pardo

2007-01-01

We evaluated foliar and forest floor chemistry across a gradient of N deposition in the Northeast at 11 red spruce (Picea rubens Sarg.) sites in 1987/1988 and foliar and forest floor chemistry and basal area growth at six paired spruce and deciduous sites in 1999. The six red spruce plots were a subset of the original 1987/1988 spruce sites. In 1999...

Fog and Phosphorous:Mist Connections?

NASA Astrophysics Data System (ADS)

Weathers, K. C.; Caraco, N. F.; Ewing, H. A.

2005-12-01

Fog (or cloud) is an important vector for delivering water, nutrients and pollutants to many coastal and montane ecosystems worldwide. Previous research has demonstrated that elements and ions whose sources are thought to be atmospheric, such as nitrogen and sulfur, can be deposited in substantial quantities via fog water deposition. However, the ecologically-important nutrient, phosphorous (P), is thought to derive primarily from guano or terrestrial sources; it has not been demonstrated to be deposited in significant quantities via rain water, for example. Here we suggest that phosphorous may be quite prevalent in fog water and that the atmospheric deposition of phosphorous to the forest floor is significant. Phosphate appears to be either immobilized or utilized in the forest floor. We examine the concentrations of phosphorous in fog water from several ecosystems in the Americas and the spatial patterns of P movement in a fog-dominated, redwood forest in Sonoma County, CA. Phosphate concentrations were surprisingly high, ranging from 0.002 to 2.9 mg/L, in fog samples from near-coast and montane ecosystems. Phosphate in fog water appears to be derived from a crustal source as demonstrated by the strong relationship between phosphorous concentrations in fog and K:Na ratios. Fog water phosphorous inputs to the forest floor were observed to decline exponentially and vary significantly from edge to interior in a redwood forest. Phosphate via fog deposition can be detected in shallow soil zones but not at greater depths, and only at the forest edge, during the summer fog season.

Does the precipitation redistribution of the canopy sense in the moisture pattern of the forest litter?

NASA Astrophysics Data System (ADS)

Zagyvai-Kiss, Katalin Anita; Kalicz, Péter; Csáfordi, Péter; Kucsara, Mihály; Gribovszki, Zoltán

2013-04-01

Precipitation is trapped and temporarily stored by the surfaces of forest crown (canopy interception) and forest litter (litter interception). The stemflow and throughfall reach the litter, thus theoretically the litter moisture content depends on these parts of precipitation. Nowadays the moisture pattern of the forest floor, both spatial and temporal scale, have growing respect for the forestry. The transition to the continuous cover forestry induce much higher variability compared to the even aged, more-less homogeneous, monocultural stands. The gap cutting is one of the key methods in the Hungarian forestry. There is an active discussion among the forest professionals how to determine the optimal gap size to maintain the optimal conditions for the seedlings. Among the open questions is how to modify surrounding trees the moisture pattern of the forest floor in the gap? In the early steps of a multidisciplinary project we processed some available data, to estimate the spatial dependency between the water content of forest litter and the spatial pattern of the canopy represented by the tree trunk. The maximum water content depends on dry weight of litter, thus we also analysed that parameter. Data were measured in three different forest ecosystems: a middle age beech (Fagus sylvatica), a sessile oak (Quercus petraea) and a spruce (Picea abies) stand. The study site (Hidegvíz Valley Research Cathcment) is located in Sopron Hills at the eastern border of the Alps. Litter samples were collected under each stand (occasionally 10-10 pieces from 40?40 cm area) and locations of the samples and neighbouring trees were mapped. We determined dry weight and the water content of litter in laboratory. The relationship between water content and the distance of tree trunks in case of spruce and oak stands were not significant and in case of the beech stand was weakly significant. Climate change effects can influence significantly forest floor moisture content, therefore this factor has also taken into account. Acknowledgement: The research was financially supported by the TÁMOP-4.2.2.A-11/1/KONV-2012-0004 and TÁMOP-4.2.2.A-11/1/KONV-2012-0013 joint EU-national research projects.

Control of depth to permafrost and soil temperature by the forest floor in black spruce/feathermoss communities.

Treesearch

C.T. Dyrness

1982-01-01

Changes in depth to permafrost and soil temperature were investigated for 4 years after treatment of the forest floor on small plots by fire and mechanical removal of half the forest floor layer and the entire layer. The only treatments to show a consistent, statistically significant effect were the mechanical removals. Fire treatments usually did not have a...

Type of litter determines the formation and properties of charred material during wildfires

NASA Astrophysics Data System (ADS)

Chavez, Bruno; Fonturbel, M. Teresa; Salgado, Josefa; García-Oliva, Felipe; Vega, Jose A.; Merino, Agustin

2014-05-01

Wildfire is one of the most important disturbances all over the World, affecting both the amount and composition of forest floor and mineral soils. In comparison with unburnt areas, wildfire-affected forest floor usually shows lower contents of labile C compounds and higher concentrations of recalcitrant aromatic forms. These changes in composition can have important impact on biogeochemical cycles and therefore ecosystem functions. Although burning of different types of litter can lead to different amount and types of pyrogenic compounds, this aspect has not been evaluated yet. The effect of wildfire on SOM composition and stability were evaluated in five major types of non-wood litter in Mediterranean ecosystems: Pinus nigra, E. arborea, P. pinaster, U. europaeus and Eucalyptus globulus. In each of these ecosystems, forest floor samples from different soil burn severities were sampled. Soil burnt severities were based on visual signs of changes in forest floor and deposition of ash. Pyrogenic carbon quality were analysed using elementary analysis, solid-state 13 C nuclear magnetic resonance spectroscopy, Reflectance Infrared Fourier Transform (FTIR) and thermal analysis (simultaneous DSC-TG). The study showed that the different types of litter influenced the formation and characteristics of charred material. They differed in the temperature at which they start to be formed, the amounts of charred compounds and in their chemical composition. The resulting charred materials from the different litter, showed an important variability in the degree of carbonitation/aromatization. Unlike the biochar obtained through pyrolysis of woody sources, which contains exclusively aromatic structures, in the charred material produced in some litter, lignin, cellulose and even cellulose persist even in the high soil burnt severity. Coinciding with increases in aromatic contents, important decreases in atomic H/C and O/C ratios were recorded. However, the values found in some litters, were higher than 0.5, suggesting that low degree of carbonization/aromatization. Although burning also led to compounds of higher thermal recalcitrance (increases in T50 values), values recorded in some litters were lower than those measured in highly polycondensed aromatic compounds. The differences found among the different forest floor cannot be only attributable to the initial SOM composition of the litter. Other aspects, such as the different thermal sensitivity, flammability and different conditions during wildfire (temperatures, combustion duration, oxygen concentrations) could also have contributed.

The role of litterfall in transferring Fukushima-derived radiocesium to a coniferous forest floor.

PubMed

Teramage, Mengistu T; Onda, Yuichi; Kato, Hiroaki; Gomi, Takashi

2014-08-15

The deposition of Fukushima-derived radiocesium via falling litter in a coniferous forest 180 km downwind immediately following the nuclear power plant accident was investigated. The litterfall contribution to the transfer of radiocesium from the forest canopy to the forest floor was determined, and this pathway was compared with hydrological pathways. The results demonstrated that during the observation period, a total of approximately 5.5 kBq m(-2) of Fukushima-derived radiocesium was deposited on the forest floor through throughfall (53%), stemflow (2.3%) and litterfall (45%) routes. The data revealed that the contributions of hydrological pathways became less important as time passed. However, the litterfall route, which transferred approximately 31% (2.5±0.6 kBq m(-2)) of the local fallout within the observation period, continued depositing radiocesium onto the forest floor. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of elevated CO2 and temperature on forest floor litter decomposition and chemistry

EPA Science Inventory

Forest floor can be a major component of the carbon held in forested soils. In mature forests it represents the balance between additions and decomposition under current climate conditions. Because of its position at the soil surface, this reservoir of C is highly susceptible...

Linking chemical elements in forest floor humus (Oh-horizon) in the Czech Republic to contamination sources.

PubMed

Sucharova, Julie; Suchara, Ivan; Hola, Marie; Reimann, Clemens; Boyd, Rognvald; Filzmoser, Peter; Englmaier, Peter

2011-05-01

While terrestrial moss and other plants are frequently used for environmental mapping and monitoring projects, data on the regional geochemistry of humus are scarce. Humus, however, has a much larger life span than any plant material. It can be seen as the "environmental memory" of an area for at least the last 60-100 years. Here concentrations of 39 elements determined by ICP-MS and ICP AES, pH and ash content are presented for 259 samples of forest floor humus collected at an average sample density of 1 site/300 km2 in the Czech Republic. The scale of anomalies linked to known contamination sources (e.g., lignite mining and burning, metallurgical industry, coal fired power plants, metal smelters) is documented and discussed versus natural processes influencing humus quality. Most maps indicate a local impact from individual contamination sources: often more detailed sampling than used here would be needed to differentiate between likely sources. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of the Forest Floor and Acorn Placement on Establishment and Early Development of Water Oak Seedlings

Treesearch

Yanfei Guo; Michael G. Shelton; B.R. Lockhart

1999-01-01

Effects of the forest floor (0, 10, 20, 30,40, and 50 Mg/ha) and acorn placement (buried 1.5 cm below the soil surface, pressed into the soil surface, and placed within the forest floor) on establishment and early development of water oak (Quercus nigra L.) seedlings were tested in a 6 x 3 factorial study in southeastern Arkansas. Increasing...

Properties of dissolved and total organic matter in throughfall, stemflow and forest floor leachate of Central European forests

NASA Astrophysics Data System (ADS)

Bischoff, S.; Schwarz, M. T.; Siemens, J.; Thieme, L.; Wilcke, W.; Michalzik, B.

2014-10-01

For the first time, we investigated the composition of dissolved organic matter (DOM) compared to total OM (TOM, consisting of DOM and particulate OM, POM) in throughfall, stemflow and forest floor leachate of beech and spruce forests using solid state 13C nuclear magnetic resonance spectroscopy. We hypothesized that the composition and properties of OM in forest ecosystem water samples differed between DOM and TOM and between the two tree species. Under beech, a contribution of phyllosphere-derived fresh POM was echoed in structural differences. Compared with DOM, TOM exhibited higher relative intensities for the alkyl C region, representing aliphatic C from less decomposed organic material, and lower relative intensities for lignin-derived and aromatic C of the aryl C region, resulting in lower aromaticity indices and reduced humification intensities. Since differences in the structural composition of DOM and TOM were less pronounced under spruce than under beech, we suspect a~tree species-related effect on the origin of OM composition and resulting properties (e.g. recalcitrance, allelopathic potential).

Nitrogen dynamics across silvicultural canopy gaps in young forests of western Oregon

USGS Publications Warehouse

Thiel, A.L.; Perakis, S.S.

2009-01-01

Silvicultural canopy gaps are emerging as an alternative management tool to accelerate development of complex forest structure in young, even-aged forests of the Pacific Northwest. The effect of gap creation on available nitrogen (N) is of concern to managers because N is often a limiting nutrient in Pacific Northwest forests. We investigated patterns of N availability in the forest floor and upper mineral soil (0-10 cm) across 6-8-year-old silvicultural canopy gaps in three 50-70-year-old Douglas-fir forests spanning a wide range of soil N capital in the Coast Range and Cascade Mountains of western Oregon. We used extractable ammonium (NH4+) and nitrate (NO3-) pools, net N mineralization and nitrification rates, and NH4+ and NO3- ion exchange resin (IER) concentrations to quantify N availability along north-south transects run through the centers of 0.4 and 0.1 ha gaps. In addition, we measured several factors known to influence N availability, including litterfall, moisture, temperature, and decomposition rates. In general, gap-forest differences in N availability were more pronounced in the mineral soil than in the forest floor. Mineral soil extractable NH4+ and NO3- pools, net N mineralization and nitrification rates, and NH4+ and NO3- IER concentrations were all significantly elevated in gaps relative to adjacent forest, and in several cases exhibited significantly greater spatial variability in gaps than forest. Nitrogen availability along the edges of gaps more often resembled levels in the adjacent forest than in gap centers. For the majority of response variables, there were no significant differences between northern and southern transect positions, nor between 0.4 and 0.1 ha gaps. Forest floor and mineral soil gravimetric percent moisture and temperature showed few differences along transects, while litterfall carbon (C) inputs and litterfall C:N ratios in gaps were significantly lower than in the adjacent forest. Reciprocal transfer incubations of mineral soil samples between gap and forest positions revealed that soil originating from gaps had greater net nitrification rates than forest samples, regardless of incubation environment. Overall, our results suggest that increased N availability in 6-8-year-old silvicultural gaps in young western Oregon forests may be due more to the quality and quantity of litterfall inputs resulting from early-seral species colonizing gaps than by changes in temperature and moisture conditions caused by gap creation.

Controls on fallen leaf chemistry and forest floor element masses in native and novel forests across a tropical island

Treesearch

H.E. Erickson; E.H. Helmer; T.J. Brandeis; A.E. Lugo

2014-01-01

Litter chemistry varies across landscapes according to factors rarely examined simultaneously. We analyzed 11 elements in forest floor (fallen) leaves and additional litter components from 143 forest inventory plots systematically located across Puerto Rico, a tropical island recovering from large-scale forest clearing. We assessed whether three existing, independently...

A small single-nozzle rainfall simulator to measure erosion response on different burn severities in southern British Columbia, Canada

NASA Astrophysics Data System (ADS)

Covert, Ashley; Jordan, Peter

2010-05-01

To study the effects of wildfire burn severity on runoff generation and soil erosion from high intensity rainfall, we constructed an effective yet simple rainfall simulator that was inexpensive, portable and easily operated by two people on steep, forested slopes in southern British Columbia, Canada. The entire apparatus, including simulator, pumps, hoses, collapsible water bladders and sample bottles, was designed to fit into a single full-sized pick-up truck. The three-legged simulator extended to approximately 3.3 metres above ground on steep slopes and used a single Spraying Systems 1/2HH-30WSQ nozzle which can easily be interchanged for other sized nozzles. Rainfall characteristics were measured using a digital camera which took images of the raindrops against a grid. Median drop size and velocity 5 cm above ground were measured and found to be 3/4 of the size of natural rain drops of that diameter class, and fell 7% faster than terminal velocity. The simulator was used for experiments on runoff and erosion on sites burned in 2007 by two wildfires in southern British Columbia. Simulations were repeated one and two years after the fires. Rainfall was simulated at an average rate of 67 mm hr-1 over a 1 m2 plot for 20 minutes. This rainfall rate is similar to the 100 year return period rainfall intensity for this duration at a nearby weather station. Simulations were conducted on five replicate 1 m2 plots in each experimental unit including high burn severity, moderate burn severity, unburned, and unburned with forest floor removed. During the simulation a sample was collected for 30 seconds every minute, with two additional samples until runoff ceased, resulting in 22 samples per simulation. Runoff, overland flow coefficient, infiltration and sediment yield were compared between treatments. Additional simulations were conducted immediately after a 2009 wildfire to test different mulch treatments. Typical results showed that runoff on plots with high burn severity and with forest floor removed was similar, reaching on average a steady rate of about 60% of rainfall rate after about 7 minutes. Runoff on unburned plots with intact forest floor was much lower, typically less than 20% of rainfall rate. Sediment yield was greatest on plots with forest floor removed, followed by severely burned plots. Sediment yield on unburned and moderately burned plots was very low to zero. These results are consistent with qualitative observations made following several extreme rainfall events on recent burns in the region.

Some Forest Floor Fuelbed Characteristics of Black Oak Stands in Southeast Missouri

Treesearch

John S. Crosby; Robert M. Loomis

1974-01-01

Black oak forest floor fuelbeds under 20 - and 40-year-old stands in southeast Missouri averaged 6.4 and 4.2 inches in depth, respectively. Loose Litter averaged 2.0 and 2.9 tons per acre and 3.3 inces in depth. Bulk density of litter averaged 0.33 and 0.49 lb/ft3 and of total forest floor 0.89 and 1.10 lbs/ft3, respectively.

Seasonal relationships between precipitation, forest floor, and streamwater nitrogen, Isle Royale, Michigan

USGS Publications Warehouse

Stottlemyer, R.; Toczydlowski, D.

1999-01-01

The Upper Great Lakes receive large amounts of precipitation-NH4/+ and moderate NO3/- inputs. Increased atmospheric inorganic N input has led to concern about ecosystem capacity to utilize excess N. This paper summarizes a 5-yr study of seasonal N content and flux in precipitation, snowpack, forest floor, and streamwater in order to assess the source of inorganic N outputs in streamflow from a small boreal watershed. Average precipitation N input was 3 kg ha-1 yr-1. The peak snowpack N content averaged 0.55 kg ha-1. The forest floor inorganic N pool was ???2 kg ha-1, eight times larger than monthly precipitation N input. The inorganic N pool size peaked in spring and early summer. Ninety percent of the forest floor inorganic N pool was made up of NH4/+-N. Forest floor inorganic N pools generally increased with temperature. Net N mineralization was 15 kg ha-1 yr-1, and monthly rates peaked in early summer. During winter, the mean monthly net N mineralization rate was twice the peak snowpack N content. Streamwater NO3/- concentration peaked in winter, and inorganic N output peaked in late fall. Beneath the dominant boreal forest species, net N mineralization rates were positively correlated (P < 0.05) with streamwater NO3/- concentrations. Forest floor NO3/- pools beneath alder [Alnus rugosa (Du Roi) Spreng] were positively correlated (P < 0.01) to streamwater NO3/- output. At the watershed mouth, streamwater NO3/- concentrations were positively correlated (P < 0.05) with precipitation NO3/- input and precipitation amount. The relatively small snowpack N content and seasonal precipitation N input compared to forest floor inorganic N pools and net N mineralization rates, the strong ecosystem retention of precipitation N inputs, and the seasonal streamwater NO3/- concentration and output pattern all indicated that little streamwater NO3/- came directly from precipitation or snowmelt.The Upper Great Lakes receive large amounts of precipitation-NH4+ and moderate NO3- inputs. Increased atmospheric inorganic N input has led to concern about ecosystem capacity to utilize excess N. This paper summarizes a 5-yr study of seasonal N content and flux in precipitation, snowpack, forest floor, and streamwater in order to assess the source of inorganic N outputs in streamflow from a small boreal watershed. Average precipitation N input was 3 kg ha-1 yr-1. The peak snowpack N content averaged 0.55 kg ha-1. The forest floor inorganic N pool was ??? 2 kg ha-1, eight times larger than monthly precipitation N input. The inorganic N pool size peaked in spring and early summer. Ninety percent of the forest floor inorganic N pool was made up of NH4+-N. Forest floor inorganic N pools generally increased with temperature. Net N mineralization was 15 kg ha-1 yr-1, and monthly rates peaked in early summer. During winter, the mean monthly net N mineralization rate was twice the peak snowpack N content. Streamwater NO3- concentration peaked in winter, and inorganic N output peaked in late fall. Beneath the dominant boreal forest species, net N mineralization rates were positively correlated (P < 0.05) with streamwater NO3- concentrations. Forest floor NO3- pools beneath alder [Alnus rugosa (Du Roi) Spreng] were positively correlated (P<0.01) to streamwater NO3- output. At the watershed mouth, streamwater NO3- concentrations were positively correlated (P < 0.05) with precipitation NO3- input and precipitation amount. The relatively small snowpack N content and seasonal precipitation N input compared to forest floor inorganic N pools and net N mineralization rates, the strong ecosystem retention of precipitation N inputs, and the seasonal streamwater NO3- concentration and output pattern all indicated that little streamwater NO3- came directly from precipitation or snowmelt.

Fifteen-year patterns of soil carbon and nitrogen following biomass harvesting

USGS Publications Warehouse

Kurth, Valerie J.; D'Amato, Anthony W.; Palik, Brian J.; Bradford, John B.

2014-01-01

The substitution of forest-derived woody biofuels for fossil fuel energy has garnered increasing attention in recent years, but information regarding the mid- and long-term effects on soil productivity is limited. We investigated 15-yr temporal trends in forest floor and mineral soil (0–30 cm) C and N pools in response to organic matter removal treatments (OMR; stem-only harvest, SOH; whole-tree harvest, WTH; and whole-tree plus forest floor removal, FFR) at three edaphically distinct aspen (Populus tremuloides Michx. and P. grandidentata Michx.) forests in the Great Lakes region. The OMR and temporal effects were generally site specific, and both were most evident in the forest floor and combined profile (mineral soil and forest floor) compared with the mineral soil alone. Forest floor and combined profile C and N pools were generally similar in the SOH and WTH treatments, suggesting that slash retention has little impact on soil C and N in this time frame. Temporal changes in C and N at one of the three sites were consistent with patterns documented following exotic earthworm invasion, but mineral soil pools at the other two sites were stable over time. Power analyses demonstrated that significant effects were more likely to be detected for temporal differences than the effects of OMR and in the combined profile than in the mineral soil. Our findings are consistent with previous work demonstrating that OMR effects on soil C and N pools are site specific and more apparent in the forest floor than the mineral soil.

Distribution of black carbon in ponderosa pine forest floor and soils following the High Park wildfire

NASA Astrophysics Data System (ADS)

Boot, C. M.; Haddix, M.; Paustian, K.; Cotrufo, M. F.

2015-05-01

Biomass burning produces black carbon (BC), effectively transferring a fraction of the biomass C from an actively cycling pool to a passive C pool, which may be stored in the soil. Yet the timescales and mechanisms for incorporation of BC into the soil profile are not well understood. The High Park fire (HPF), which occurred in northwestern Colorado in the summer of 2012, provided an opportunity to study the effects of both fire severity and geomorphology on properties of carbon (C), nitrogen (N) and BC in the Cache La Poudre River drainage. We sampled montane ponderosa pine forest floor (litter plus O-horizon) and soils at 0-5 and 5-15 cm depth 4 months post-fire in order to examine the effects of slope and burn severity on %C, C stocks, %N and BC. We used the benzene polycarboxylic acid (BPCA) method for quantifying BC. With regard to slope, we found that steeper slopes had higher C : N than shallow slopes but that there was no difference in BPCA-C content or stocks. BC content was greatest in the forest floor at burned sites (19 g BPCA-C kg-1 C), while BC stocks were greatest in the 5-15 cm subsurface soils (23 g BPCA-C m-2). At the time of sampling, unburned and burned soils had equivalent BC content, indicating none of the BC deposited on the land surface post-fire had been incorporated into either the 0-5 or 5-15 cm soil layers. The ratio of B6CA : total BPCAs, an index of the degree of aromatic C condensation, suggested that BC in the 5-15 cm soil layer may have been formed at higher temperatures or experienced selective degradation relative to the forest floor and 0-5 cm soils. Total BC soil stocks were relatively low compared to other fire-prone grassland and boreal forest systems, indicating most of the BC produced in this system is likely lost, either through erosion events, degradation or translocation to deeper soils. Future work examining mechanisms for BC losses from forest soils will be required for understanding the role BC plays in the global carbon cycle.

The Effects of Tree Species on Soil Organic Carbon Content and Distribution in South Korea.

NASA Astrophysics Data System (ADS)

Oh, N. H.; Cha, J. Y.; Cha, Y. K.

2016-12-01

Soil organic carbon (SOC) content of forests is controlled by the dynamic balance between photosynthesis and respiration. Changes of tree species can affect the SOC content both directly by alteration in quantity and quality of newly photosynthesized inputs, and indirectly by changes in soil conditions such as root distribution and soil microbial communities. Although many studies have been conducted on the effects of tree species on SOC, the results are mixed possibly due to the locality and the scales of the studies. This can be overcome by systematic analysis on extensively collected samples of forest floors and soils. We investigated the impacts of tree species, dominantly pines (Pinus) and oaks (Quercus), on SOC stock and distribution in South Korea by conducting ANOVA and GLM analyses using the Korean National Forest Inventory data collected from 640 plots during 2007-2010. The trees used in the data were relatively young with 67% of them being less than 40 years old because of a nation-wide reforestation program started in the 1970s. The results demonstrated a clear contrast between Pinus and Quercus, depending on soil horizons. Forest floor SOC under Pinus was 6.98 ton C/ha, significantly higher than 5.30 ton C/ha under Quercus. In contrast, SOC in mineral soils was 51.31 ton C/ha under Pinus, significantly lower than 64.76 ton C/ha under Quercus. The total SOC content including both forest floor and mineral soils was significantly higher under Quercus than Pinus, suggesting that Quercus has a potential to sequester more atmospheric CO2 in the forests in Korea.

Contrasting responses to drought of forest floor CO2 efflux in a loblolly pine plantation and a nearby Oak-Hickory forest

Treesearch

S. Palmroth; Chris A. Maier; Heather R. McCarthy; A. C. Oishi; H. S. Kim; Kurt H. Johnsen; Gabrial G. Katul; Ram Oren

2005-01-01

Forest floor C02 efflux (Fff) depends on vegetation type, climate, and soil physical properties. We assessed the effects of biological factors on Fff by comparing a maturing pine plantation (PP) and a nearby mature Oak-Hickory-type hardwood forest (HW). Fff was measured...

Changes in necromass and nutrients on the forest floor of a palm floodplain forest in the Luquillo mountains of Puerto Rico.

Treesearch

ARIEL E. LUGO; JORGE L. FRANGI

2003-01-01

We studied changes that occurred between 1980 and 2000 in forest floor biomass (necromass+ biomass of herbaceous plants), nutrient stocks, and plant composition of a Prestoea montana floodplain forest. The forest was located in the Luquillo Mountains of Puerto Rico. Several storms and hurricanes passed near the study site during that period, the most severe being...

Soil variation and sampling intensity under red pine and aspen in Minnesota.

Treesearch

David H. Alban

1974-01-01

In red pine or aspen stands only two soil samples were needed to estimate (+/- 10%, 95% confidence) pH, bulk density, or sand, but 25 to 60 samples were required to estimate N, P, K, Ca, Mg, available water, or silt + clay. To estimate most forest floor properties required 30 to 50 samples in red pine stands, but only about half as many in aspen stands.

Sphagnum mosses limit total carbon consumption during fire in Alaskan black spruce forests

Treesearch

G. Shetler; .R. Turetsky; E. Kane; E. Kasischke

2008-01-01

The high water retention of hummock-forming Sphagnum species minimizes soil moisture fluctuations and might protect forest floor organic matter from burning during wildfire. We hypothesized that Sphagnum cover reduces overall forest floor organic matter consumption during wildfire compared with other ground-layer vegetation. We...

Transforming Pinus pinaster forest to recreation site: preliminary effects on LAI, some forest floor, and soil properties.

PubMed

Öztürk, Melih; Bolat, İlyas

2014-04-01

This study investigates the effects of forest transformation into recreation site. A fragment of a Pinus pinaster plantation forest was transferred to a recreation site in the city of Bartın located close to the Black Sea coast of northwestern Turkey. During the transformation, some of the trees were selectively removed from the forest to generate more open spaces for the recreationists. As a result, Leaf Area Index (LAI) decreased by 0.20 (about 11%). Additionally, roads and pathways were introduced into the site together with some recreational equipment sealing parts of the soil surface. Consequently, forest environment was altered with a semi-natural landscape within the recreation site. The purpose of this study is to assess the effects of forest transformation into recreation site particularly in terms of the LAI parameter, forest floor, and soil properties. Preliminary monitoring results indicate that forest floor biomass is reduced by 26% in the recreation site compared to the control site. Soil temperature is increased by 15% in the recreation site where selective removal of trees expanded the gaps allowing more light transmission. On the other hand, the soil bulk density which is an indicator of soil compaction is unexpectedly slightly lower in the recreation site. Organic carbon (C(org)) and total nitrogen (N(total)) together with the other physical and chemical parameter values indicate that forest floor and soil have not been exposed to much disturbance. However, subsequent removal of trees that would threaten the vegetation, forest floor, and soil should not be allowed. The activities of the recreationists are to be concentrated on the paved spaces rather than soil surfaces. Furthermore, long-term monitoring and management is necessary for both the observation and conservation of the site.

Establishment of ectomycorrhizal fungal community on isolated Nothofagus cunninghamii seedlings regenerating on dead wood in Australian wet temperate forests: does fruit-body type matter?

PubMed

Tedersoo, Leho; Gates, Genevieve; Dunk, Chris W; Lebel, Teresa; May, Tom W; Kõljalg, Urmas; Jairus, Teele

2009-08-01

Decaying wood provides an important habitat for animals and forms a seed bed for many shade-intolerant, small-seeded plants, particularly Nothofagus. Using morphotyping and rDNA sequence analysis, we compared the ectomycorrhizal fungal community of isolated N. cunninghamii seedlings regenerating in decayed wood against that of mature tree roots in the forest floor soil. The /cortinarius, /russula-lactarius, and /laccaria were the most species-rich and abundant lineages in forest floor soil in Australian sites at Yarra, Victoria and Warra, Tasmania. On root tips of seedlings in dead wood, a subset of the forest floor taxa were prevalent among them species of /laccaria, /tomentella-thelephora, and /descolea, but other forest floor dominants were rare. Statistical analyses suggested that the fungal community differs between forest floor soil and dead wood at the level of both species and phylogenetic lineage. The fungal species colonizing isolated seedlings on decayed wood in austral forests were taxonomically dissimilar to the species dominating in similar habitats in Europe. We conclude that formation of a resupinate fruit body type on the underside of decayed wood is not necessarily related to preferential root colonization in decayed wood. Rather, biogeographic factors as well as differential dispersal and competitive abilities of fungal taxa are likely to play a key role in structuring the ectomycorrhizal fungal community on isolated seedlings in decaying wood.

Soil organic carbon and nitrogen accumulation on coal mine spoils reclaimed with maritime pine (Pinus pinaster Aiton) in Agacli-Istanbul.

PubMed

Sever, Hakan; Makineci, Ender

2009-08-01

Mining operations on open coal mines in Agacli-Istanbul have resulted in the destruction of vast amounts of land. To rehabilitate these degraded lands, plantations on this area began in 1988. Twelve tree species were planted, however, the most planted tree species was maritime pine (Pinus pinaster Aiton). This study performed on 14 sample plots randomly selected in maritime pine plantations on coal mine soil/spoils in 2005. Soil samples were taken from eight different soil layers (0-1, 1-3, 3-5, 5-10, 10-20, 20-30, 30-40 and 40-50 cm) into the soil profile. On soil samples; fine soil fraction (<2 mm), soil acidity (pH), organic carbon (C(org)) and total nitrogen (N(t)) contents were investigated, and results were compared statistically among soil layers. As a result, 17 years after plantations, total forest floor accumulation determined as 17,973.20 kg ha(-1). Total nitrogen and organic matter amounts of forest floor were 113.90 and 14,640.92 kg ha(-1) respectively. Among soil layers, the highest levels of organic carbon (1.77%) and total nitrogen (0.096%) and the lowest pH value (pH 5.38) were found in 0-1 cm soil layer, and the variation differs significantly among soil layers. Both organic carbon and total nitrogen content decreased, pH values increased from 0-1 to 5-10 cm layer. In conclusion, according to results obtained maritime pine plantations on coal mine spoils; slow accumulation and decomposition of forest floor undergo simultaneously. Depending on these changes organic carbon and total nitrogen contents increased in upper layer of soil/spoil.

Upland log volumes and conifer establishment patterns in two northern, upland old-growth redwood forests, a brief synopsis

Treesearch

Daniel J. Porter; John O. Sawyer

2007-01-01

We characterized the volume, weight and top surface area of naturally fallen logs in an old-growth redwood forest, and quantified conifer recruit densities on these logs and on the surrounding forest floor. We report significantly greater conifer recruit densities on log substrates as compared to the forest floor. Log substrate availability was calculated on a per...

Mercury in litterfall and upper soil horizons in forested ecosystems in Vermont, USA.

PubMed

Juillerat, Juliette I; Ross, Donald S; Bank, Michael S

2012-08-01

Mercury (Hg) is an atmospheric pollutant that, in forest ecosystems, accumulates in foliage and upper soil horizons. The authors measured soil and litterfall Hg at 15 forest sites (northern hardwood to mixed hardwood/conifer) throughout Vermont, USA, to examine variation among tree species, forest type, and soils. Differences were found among the 12 tree species sampled from at least two sites, with Acer pensylvanicum having significantly greater litterfall total Hg concentration. Senescent leaves had greater Hg concentrations if they originated lower in the canopy or had higher surface:weight ratios. Annual litterfall Hg flux had a wide range, 12.6 to 28.5 µg/m(2) (mean, 17.9 µg/m(2) ), not related to forest type. Soil and Hg pools in the Oi horizon (litter layer) were not related to the measured Hg deposition flux in litterfall or to total modeled Hg deposition. Despite having lower Hg concentrations, upper mineral soil (A horizons) had greater Hg pools than organic soil horizons (forest floor) due to greater bulk density. Significant differences were found in Hg concentration and Hg/C ratio among soil horizons but not among forest types. Overall, our findings highlight the importance of site history and the benefits of collecting litterfall and soils simultaneously. Observed differences in forest floor Hg pools were strongly correlated with carbon pools, which appeared to be a function of historic land-use patterns. Copyright © 2012 SETAC.

Forest floor methane flux modelled by soil water content and ground vegetation - comparison to above canopy flux

NASA Astrophysics Data System (ADS)

Halmeenmäki, Elisa; Peltola, Olli; Haikarainen, Iikka; Ryhti, Kira; Rannik, Üllar; Pihlatie, Mari

2017-04-01

Methane (CH4) is an important and strong greenhouse gas of which atmospheric concentration is rising. While boreal forests are considered as an important sink of CH4 due to soil CH4 oxidation, the soils have also a capacity to emit CH4. Moreover, vegetation is shown to contribute to the ecosystem-atmosphere CH4 flux, and it has been estimated to be the least well known natural sources of CH4. In addition to well-known CH4 emissions from wetland plants, even boreal trees have been discovered to emit CH4. At the SMEAR (Station for Measuring Ecosystem-Atmosphere Relations) II station in Hyytiälä, southern Finland (61° 51' N, 24°17' E; 181 m asl), we have detected small CH4 emissions from above the canopy of a Scots pine (Pinus sylvestris) dominated forest. To assess the origin of the observed emissions, we conducted forest floor CH4 flux measurements with 54 soil chambers at the footprint area of the above canopy flux measurements during two growing seasons. In addition, we measured the soil volumetric water content (VWC) every time next to the forest floor chamber measurements, and estimated vegetation coverages inside the chambers. In order to model the forest floor CH4 flux at the whole footprint area, we combined lidar (light detection and ranging) data with the field measurements. To predict the soil water content and thus the potential CH4 flux, we used local elevation, slope, and ground return intensity (GRI), calculated from the lidar data (National Land Survey of Finland). We categorized the soil chambers into four classes based on the VWC so that the class with the highest VWC values includes all the soil chambers with a potential to emit CH4. Based on a statistically significant correlation between the VWC and the forest floor CH4 flux (r = 0.30, p < 0.001), we modelled the potential forest floor CH4 flux of the whole area. The results of the soil chamber measurements show a few areas of the forest floor with significant CH4 emissions. The modelled map of the potential CH4 flux is consistent with the measurements of the flux and the VWC, indicating that the wetter areas have potential for CH4 emissions, while the drier areas have potential for CH4 uptake. Preliminary results of the vegetation coverage show a positive correlation between the first year forest floor CH4 flux and the coverage of Sphagnum spp. mosses (r = 0.55, p < 0.001). Furthermore, we will include the vegetation coverage to the analysis, and compare the modelled forest floor CH4 flux with the measured above canopy flux. This ongoing research will give valuable information about the CH4 sources and dynamics in boreal forests.

Short-term recovery of NH4-15N applied to a temperate forest inceptisol and ultisol in east Tennessee USA

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

Garten Jr, Charles T; Brice, Deanne Jane; Todd Jr, Donald E

2007-11-01

The short-term fate and retention of ammonium (NH4)-{sup 15}nitrogen (N) applied to two types of forest soils in east Tennessee was investigated. Four ridgetop forests, predominantly oak (Quercus spp.), were studied. Five applications of NH{sub 4}-{sup 15}N tracer were made to the forest floor at 2- to 4-week intervals over a 14-week period in 2004. Nitrogen-15 recovery in the forest floor, fine roots (<2 mm), and the mineral soil (0-20 cm) was calculated at 6, 21, and 42 weeks after the last application. Most of the {sup 15}N was retained in the forest floor and the mineral soil, with onlymore » small amounts ({approx}<2%) found in roots from both soil layers. Recovery of NH{sub 4}-{sup 15}N was greater in Inceptisols, which had a wider carbon (C)-to-N ratio than Ultisols. For both soil types, higher NH{sub 4}-{sup 15}N recoveries and long retention times (half-lives>100 weeks) indicated the forest floor is an effective filter for atmospheric N inputs.« less

Changes in canopy cover alter surface air and forest floor temperature in a high-elevation red spruce (Picea rubens Sarg.) forest

Treesearch

Johnny L. Boggs; Steven G. McNulty

2010-01-01

The objective of this study is to describe winter and summer surface air and forest floor temperature patterns and diurnal fluctuations in high-elevation red spruce (Picea rubens Sarg.) forests with different levels of canopy cover. In 1988, a series of 10- x 10-meter plots (control, low nitrogen [N] addition, and high nitrogen addition) were...

Impacts of invasive earthworms on soil mercury cycling: Two mass balance approaches to an earthworm invasion in a northern Minnesota forest

Treesearch

Sona Psarska; Edward A. Nater; Randy Kolka

2016-01-01

Invasive earthworms perturb natural forest ecosystems that initially developed without them, mainly by consuming the forest floor (an organic rich surficial soil horizon) and by mixing the upper parts of the soil. The fate of mercury (Hg) formerly contained in the forest floor is largely unknown. We used two mass balance approaches (simple mass balance and geochemical...

Microhabitat effects of litter temperature and moisture on forest-floor invertebrate communities

Treesearch

Tim A. Christiansen; Sue A. Perry; William B. Perry

1996-01-01

Litter temperature and moisture may be altered due to changes in global climate. We investigated the effect of small changes in litter temperature and moisture on forest-floor communities in West Virginia.

Soil moisture sensitivity of autotrophic and heterotrophic forest floor respiration in boreal xeric pine and mesic spruce forests

NASA Astrophysics Data System (ADS)

Ťupek, Boris; Launiainen, Samuli; Peltoniemi, Mikko; Heikkinen, Jukka; Lehtonen, Aleksi

2016-04-01

Litter decomposition rates of the most process based soil carbon models affected by environmental conditions are linked with soil heterotrophic CO2 emissions and serve for estimating soil carbon sequestration; thus due to the mass balance equation the variation in measured litter inputs and measured heterotrophic soil CO2 effluxes should indicate soil carbon stock changes, needed by soil carbon management for mitigation of anthropogenic CO2 emissions, if sensitivity functions of the applied model suit to the environmental conditions e.g. soil temperature and moisture. We evaluated the response forms of autotrophic and heterotrophic forest floor respiration to soil temperature and moisture in four boreal forest sites of the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) by a soil trenching experiment during year 2015 in southern Finland. As expected both autotrophic and heterotrophic forest floor respiration components were primarily controlled by soil temperature and exponential regression models generally explained more than 90% of the variance. Soil moisture regression models on average explained less than 10% of the variance and the response forms varied between Gaussian for the autotrophic forest floor respiration component and linear for the heterotrophic forest floor respiration component. Although the percentage of explained variance of soil heterotrophic respiration by the soil moisture was small, the observed reduction of CO2 emissions with higher moisture levels suggested that soil moisture response of soil carbon models not accounting for the reduction due to excessive moisture should be re-evaluated in order to estimate right levels of soil carbon stock changes. Our further study will include evaluation of process based soil carbon models by the annual heterotrophic respiration and soil carbon stocks.

Identifying calcium sources at an acid deposition-impacted spruce forest: A strontium isotope, alkaline earth element multi-tracer approach

USGS Publications Warehouse

Bullen, T.D.; Bailey, S.W.

2005-01-01

Depletion of calcium from forest soils has important implications for forest productivity and health. Ca is available to fine feeder roots from a number of soil organic and mineral sources, but identifying the primary source or changes of sources in response to environmental change is problematic. We used strontium isotope and alkaline earth element concentration ratios of trees and soils to discern the record of Ca sources for red spruce at a base-poor, acid deposition-impacted watershed. We measured 87Sr/86Sr and chemical compositions of cross-sectional stemwood cores of red spruce, other spruce tissues and sequential extracts of co-located soil samples. 87Sr/86Sr and Sr/Ba ratios together provide a tracer of alkaline earth element sources that distinguishes the plant-available fraction of the shallow organic soils from those of deeper organic and mineral soils. Ca/Sr ratios proved less diagnostic, due to within-tree processes that fractionate these elements from each other. Over the growth period from 1870 to 1960, 87Sr/86Sr and Sr/Ba ratios of stemwood samples became progressively more variable and on average trended toward values that considered together are characteristic of the uppermost forest floor. In detail the stemwood chemistry revealed an episode of simultaneous enhanced uptake of all alkaline earth elements during the growth period from 1930 to 1960, coincident with reported local and regional increases in atmospheric inputs of inorganic acidity. We attribute the temporal trends in stemwood chemistry to progressive shallowing of the effective depth of alkaline earth element uptake by fine roots over this growth period, due to preferential concentration of fine roots in the upper forest floor coupled with reduced nutrient uptake by roots in the lower organic and upper mineral soils in response to acid-induced aluminum toxicity. Although both increased atmospheric deposition and selective weathering of Ca-rich minerals such as apatite provide possible alternative explanations of aspects of the observed trends, the chemical buffering capacity of the forest floor-biomass pool limits their effectiveness as causal mechanisms. ?? Springer 2005.

7. Photo copy of blue print, (original in Forest Service ...

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

7. Photo copy of blue print, (original in Forest Service Office, Elkins, WV), November 1933. FIRST FLOOR PLAN, SECOND FLOOR PLAN. - Parsons Nursery, Manager's Residence, South side of U.S. Route 219, Parsons, Tucker County, WV

Reduction of forest floor respiration by fertilization on both carbon dioxide-enriched and reference 17-year-old loblolly pine stands

Treesearch

John R. Butnor; Kurt H. Johnsen; Ram Oren; Gabriel G. Katul

2003-01-01

Elevated atmospheric carbon dioxide (CO2e) increases soil respiration rates in forest, grassland, agricultural and wetland systems as a result of increased growth, root biomass and enhanced biological activity of soil microorganisms. Less is known about how forest floor fluxes respond to the combined effects of elevated CO...

Singular and combined effects of blowdown, salvage logging, and wildfire on forest floor and soil mercury pools

Treesearch

Carl P.J. Mitchell; Randall K. Kolka; Shawn Fraver

2012-01-01

A number of factors influence the amount of mercury (Hg) in forest floors and soils, including deposition, volatile emission, leaching, and disturbances such as fire. Currently the impact on soil Hg pools from other widespread forest disturbances such as blowdown and management practices like salvage logging are unknown. Moreover, ecological and biogeochemical...

An empirical assessment of forest floor carbon stock components across the United States

Treesearch

Christopher W. Woodall; Charles H. Perry; James A. Westfall

2012-01-01

Despite its prevalent reporting in regional/national greenhouse gas inventories (NGHGI), forest floor (FF) carbon (C) stocks (including litter, humus, and fine woody debris [FWD]) have not been empirically measured using a consistent approach across forests of the US. The goal of this study was to use the first national field inventory of litter and humic layer depths...

Fuel loadings in southwestern ecosystems of the United States

Treesearch

Stephen S. Sackett; Sally M Haase

1996-01-01

Natural forest fuel loadings cause extreme fire behavior during dry, windy weather experienced during most fire seasons in the Southwest. Fire severity is also exacerbated from burning heavy fuels, including heavy humus layers on the forest floor. Ponderosa pine and mixed conifer stands possess more than 21.7 and 44.1 tons per acre of total forest floor fuel,...

Aspen development on similar soils in Minnesota and British Columbia after compaction and forest floor removal

Treesearch

Douglas M. Stone; Richard Kabzems

2002-01-01

Forest management practices that decrease soil porosity and remove organic matter can reduce site productivity. We evaluated effects of four treatments-merchantable bole harvest (MBH) with three levels of soil compaction (none, light, or heavy), and total woody vegetation harvest plus forest floor removal (FFR)-on fifth-year regeneration and growth of aspen (...

Seeds in the Organic Layers and Soil of Four Beech-Birch-Maple Stands

Treesearch

Raymond E. Graber; Donald F. Thompson

1978-01-01

Forest floor samples were collected in northern hardwood stands 5, 38, 95, and 200+ years old. The seeds contained in these samples were germinated in a greenhouse. Thirty-five species of herbs, shrubs, and trees were identified. The largest number of species, 23, were from the 5-year-old stand. The oldest stand had the fewest species, 17. Rubus and...

Soil carbon and nitrogen pools in mid- to late-successional forest stands of the northwestern United States: Potential impact of fire

Treesearch

Deborah S. Page-Dumroese; Martin F. Jurgensen

2006-01-01

When sampling woody residue (WR) and organic matter (OM) present in forest floor, soil wood, and surface mineral soil (0­30 cm) in 14 mid- to late-successional stands across a wide variety of soil types and climatic regimes in the northwestern USA, we found that 44%-84% of carbon (C) was in WR and surface OM, whereas >80% of nitrogen (N) was in the mineral soil. In...

Prolonged Effect of Severe Wildfires on Mercury and Other Volatiles in Forest Soils of the Lake Superior Region, USA

NASA Astrophysics Data System (ADS)

Cannon, W. F.; Woodruff, L. G.

2003-12-01

Soils in Isle Royale National Park, Michigan and Voyageurs National Park, Minnesota show spatial patterns of depletion of total Hg, organic C, Se, total S, P, and Pb within areas of severe, stand-replacing wildfires that burned in 1936, approximately 65 years prior to our current study. The fires burned during a regional drought, were of high severity, and likely consumed a high percentage of organic forest-floor material (O-horizon). A "fire factor" is defined by positive correlations among Hg, C, Se, S, P, and Pb. A factor score for this six-element grouping derived from factor analysis was assigned to each sample. The scores show a high spatial correlation with the footprint of the 1936 fires in both parks, particularly for A-horizon soils. Because many of these elements are volatile, and are highly correlated with soil organic matter, observed depletions likely represent instantaneous atmospheric release during combustion of O-horizon soils coupled with decades-long reduction of organic matter on the forest floor and near-surface soils. Nearly complete combustion of the modern O-horizon would release roughly 1 mg Hg/m2 from the forest floor. Decades-long disturbance resulting from destruction of mature forests and gradual regrowth following fire also play an important role in Hg cycling. Destruction of a mature forest results in decreased deposition of Hg from litterfall as well as throughfall, which contributes Hg by wash-off of dry deposited Hg from foliar surfaces. Hg in forest soils may follow a fire-dependent cycle in which sudden Hg loss during fire is followed by a period of continued Hg loss as evasion exceeds sequestration in the early stand-replacement stage, finally to resume gradual buildup in later stages of forest regrowth. In the Lake Superior region this cycle exceeds 65 years in duration and is of the same magnitude as the fire return interval for this region. Forests that are controlled by fire-induced cycles of stand replacement may also be in continuous cycles of Hg sequestration and emission. Fire history appears to be a major determinant in the amount of Hg stored in forest soils. Fire almost certainly releases Hg to the atmosphere as forest floor material is burned and thus contributes to atmospheric Hg loads. Fire also appears to cleanse burned areas of Hg both by the atmospheric release during combustion and longer-term release during post-fire forest reorganization. Fire cleansing appears to persist for decades after severe fires and may ameliorate Hg contamination of aquatic food webs by decreasing the soil Hg load of burned watersheds.

Fire effects on temperate forest soil C and N storage.

PubMed

Nave, Lucas E; Vance, Eric D; Swanston, Christopher W; Curtis, Peter S

2011-06-01

Temperate forest soils store globally significant amounts of carbon (C) and nitrogen (N). Understanding how soil pools of these two elements change in response to disturbance and management is critical to maintaining ecosystem services such as forest productivity, greenhouse gas mitigation, and water resource protection. Fire is one of the principal disturbances acting on forest soil C and N storage and is also the subject of enormous management efforts. In the present article, we use meta-analysis to quantify fire effects on temperate forest soil C and N storage. Across a combined total of 468 soil C and N response ratios from 57 publications (concentrations and pool sizes), fire had significant overall effects on soil C (-26%) and soil N (-22%). The impacts of fire on forest floors were significantly different from its effects on mineral soils. Fires reduced forest floor C and N storage (pool sizes only) by an average of 59% and 50%, respectively, but the concentrations of these two elements did not change. Prescribed fires caused smaller reductions in forest floor C and N storage (-46% and -35%) than wildfires (-67% and -69%), and the presence of hardwoods also mitigated fire impacts. Burned forest floors recovered their C and N pools in an average of 128 and 103 years, respectively. Among mineral soils, there were no significant changes in C or N storage, but C and N concentrations declined significantly (-11% and -12%, respectively). Mineral soil C and N concentrations were significantly affected by fire type, with no change following prescribed burns, but significant reductions in response to wildfires. Geographic variation in fire effects on mineral soil C and N storage underscores the need for region-specific fire management plans, and the role of fire type in mediating C and N shifts (especially in the forest floor) indicates that averting wildfires through prescribed burning is desirable from a soils perspective.

Complementary models of tree species-soil relationships in old-growth temperate forests

USGS Publications Warehouse

Cross, Alison; Perakis, Steven S.

2011-01-01

Ecosystem level studies identify plant soil feed backs as important controls on soil nutrient availability,particularly for nitrogen and phosphorus. Although site and species specific studies of tree species soil relationships are relatively common,comparatively fewer studies consider multiple coexisting speciesin old-growth forests across a range of sites that vary underlying soil fertility. We characterized patterns in forest floor and mineral soil nutrients associated with four common tree species across eight undisturbed old-growth forests in Oregon, USA, and used two complementary conceptual models to assess tree species soil relationships. Plant soil feedbacks that could reinforce sitelevel differences in nutrient availability were assessed using the context dependent relationships model, where by relative species based differences in each soil nutrient divergedorconvergedas nutrient status changed across sites. Tree species soil relationships that did not reflect strong feedbacks were evaluated using a site independent relationships model, where by forest floor and surface mineral soil nutrient tools differed consistently by tree species across sites,without variation in deeper mineral soils. We found that theorganically cycled elements carbon, nitrogen, and phosphorus exhibited context-dependent differences among species in both forest floor and mineral soil, and most of ten followed adivergence model,where by species differences were greatest at high-nutrient sites. These patterns are consistent with the oryemphasizing biotic control of these elements through plant soil feedback mechanisms. Site independent species differences were strongest for pool so if the weather able cations calcium, magnesium, potassium,as well as phosphorus, in mineral soils. Site independent species differences in forest floor nutrients we reattributable too nespecies that displayed significant greater forest floor mass accumulation. Our finding confirmed that site-independent and context-dependent tree species-soil relationships occur simultaneouslyinold-grow the temperate forests, with context-dependent relationships strongest for organically cycled elements, and site-independent relationships strongest for weather able elements with in organic cycling phases. These models provide complementary explanations for patterns of nutrient accumulation and cycling in mixed species old-growth temperate forests.

A dataset of forest biomass structure for Eurasia.

PubMed

Schepaschenko, Dmitry; Shvidenko, Anatoly; Usoltsev, Vladimir; Lakyda, Petro; Luo, Yunjian; Vasylyshyn, Roman; Lakyda, Ivan; Myklush, Yuriy; See, Linda; McCallum, Ian; Fritz, Steffen; Kraxner, Florian; Obersteiner, Michael

2017-05-16

The most comprehensive dataset of in situ destructive sampling measurements of forest biomass in Eurasia have been compiled from a combination of experiments undertaken by the authors and from scientific publications. Biomass is reported as four components: live trees (stem, bark, branches, foliage, roots); understory (above- and below ground); green forest floor (above- and below ground); and coarse woody debris (snags, logs, dead branches of living trees and dead roots), consisting of 10,351 unique records of sample plots and 9,613 sample trees from ca 1,200 experiments for the period 1930-2014 where there is overlap between these two datasets. The dataset also contains other forest stand parameters such as tree species composition, average age, tree height, growing stock volume, etc., when available. Such a dataset can be used for the development of models of biomass structure, biomass extension factors, change detection in biomass structure, investigations into biodiversity and species distribution and the biodiversity-productivity relationship, as well as the assessment of the carbon pool and its dynamics, among many others.

A dataset of forest biomass structure for Eurasia

NASA Astrophysics Data System (ADS)

Schepaschenko, Dmitry; Shvidenko, Anatoly; Usoltsev, Vladimir; Lakyda, Petro; Luo, Yunjian; Vasylyshyn, Roman; Lakyda, Ivan; Myklush, Yuriy; See, Linda; McCallum, Ian; Fritz, Steffen; Kraxner, Florian; Obersteiner, Michael

2017-05-01

The most comprehensive dataset of in situ destructive sampling measurements of forest biomass in Eurasia have been compiled from a combination of experiments undertaken by the authors and from scientific publications. Biomass is reported as four components: live trees (stem, bark, branches, foliage, roots); understory (above- and below ground); green forest floor (above- and below ground); and coarse woody debris (snags, logs, dead branches of living trees and dead roots), consisting of 10,351 unique records of sample plots and 9,613 sample trees from ca 1,200 experiments for the period 1930-2014 where there is overlap between these two datasets. The dataset also contains other forest stand parameters such as tree species composition, average age, tree height, growing stock volume, etc., when available. Such a dataset can be used for the development of models of biomass structure, biomass extension factors, change detection in biomass structure, investigations into biodiversity and species distribution and the biodiversity-productivity relationship, as well as the assessment of the carbon pool and its dynamics, among many others.

[Vertical distribution of fuels in Pinus yunnanensis forest and related affecting factors].

PubMed

Wang, San; Niu, Shu-Kui; Li, De; Wang, Jing-Hua; Chen, Feng; Sun, Wu

2013-02-01

In order to understand the effects of fuel loadings spatial distribution on forest fire kinds and behaviors, the canopy fuels and floor fuels of Pinus yunnanensis forests with different canopy density, diameter at breast height (DBH), tree height, and stand age and at different altitude, slope grade, position, and aspect in Southwest China were taken as test objects, with the fuel loadings and their spatial distribution characteristics at different vertical layers compared and the fire behaviors in different stands analyzed. The relationships between the fuel loadings and the environmental factors were also analyzed by canonical correspondence analysis (CCA). In different stands, there existed significant differences in the vertical distribution of fuels. Pinus yunnanensis-Qak-Syzygium aromaticum, Pinus yunnanensis-oak, and Pinus yunnanensis forests were likely to occur floor fire but not crown fire, while Pinus yunnanensis-Platycladus orientalis, Pinus yunnanensis-Keteleeria fortune, and Keteleeria fortune-Pinus yunnanensis were not only inclined to occur floor fire, but also, the floor fire could be easily transformed into crown fire. The crown fuels were mainly affected by the stand age, altitude, DBH, and tree height, while the floor fuels were mainly by the canopy density, slope grade, altitude, and stand age.

Effect of species composition on carbon and nitrogen stocks in forest floor and mineral soil in Norway spruce and European beech mixed forests

NASA Astrophysics Data System (ADS)

Andivia, Enrique; Rolo, Víctor; Jonard, Mathieu; Formánek, Pavel; Ponette, Quentin

2015-04-01

Management of existing forests has been identified as the main strategy to enhance carbon sequestration and to mitigate the impact of climate change on forest ecosystems. In this direction, the conversion of Norway spruce monospecific stands into mixed stands by intermingling individuals of European beech is an ongoing trend in adaptive forest management strategies, especially in Central Europe. However, studies assessing the effect of changes in tree species composition on soil organic carbon (SOC) and nitrogen stocks are still scarce and there is a lack of scientific evidence supporting tree species selection as a feasible management option to mitigate the effects of predicted future climatic scenarios. We compared C and N stocks in the forest floor (litter and humus) and the top 10 cm of mineral soil in two monospecific stands of Norway spruce and European beech and in a mixed stand of both species. The effect of tree species composition on the C and N stocks and its spatial distribution was evaluated based on litterfall, root production, elevation and canopy opening, and by using a combination of modelling and geostatistical techniques. C stock was highest in the Norway spruce and the mixed stands, while N stock was highest in the mixed stand and lowest under European beech, with intermediate values in the Norway spruce stand. Each forest type showed differences in forest floor properties, suggesting that species composition is an important factor governing forest floor characteristics, including C and N stocks. The distribution of C and N stocks between forest soil layers was different for each forest type. C and N stocks were highest in the hummus layer under Norway spruce, whereas both stocks were lowest in the European beech stand. On the other hand, the mixed stand showed the highest C and N accumulation in the uppermost mineral soil layer, while the monospecific stands showed similar values. Litterfall was the main contribution to C and N stocks of the humus layer in monospecific stands. Forest floor stocks were also influenced by microelevation and canopy opening in the European beech stand and by microelevation in the Norway spruce stand. Root turnover and Norway spruce litterfall proportion directly increased C stocks in the mineral soil of the mixed stand. Additionally, N stock in the forest floor of the mixed stand was positively correlated with the Norway spruce litterfall proportion. Spatial analyses further confirmed that species composition was the main source of spatial variability of SOC stock in mixed stands. These results suggest that the admixture of individuals of European beech and Norway spruce may lead to a translocation of SOC from the forest floor to the better protected mineral soil layer, which might be beneficial for long term SOC sequestration.

36 CFR 910.60 - Gross floor area.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Gross floor area. 910.60 Section 910.60 Parks, Forests, and Public Property PENNSYLVANIA AVENUE DEVELOPMENT CORPORATION GENERAL GUIDELINES AND UNIFORM STANDARDS FOR URBAN PLANNING AND DESIGN OF DEVELOPMENT WITHIN THE PENNSYLVANIA AVENUE...

36 CFR 910.60 - Gross floor area.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Gross floor area. 910.60 Section 910.60 Parks, Forests, and Public Property PENNSYLVANIA AVENUE DEVELOPMENT CORPORATION GENERAL GUIDELINES AND UNIFORM STANDARDS FOR URBAN PLANNING AND DESIGN OF DEVELOPMENT WITHIN THE PENNSYLVANIA AVENUE...

Comparison of Forest Soil Carbon Dynamics at Five Sites Along a Latitudinal Gradient

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

Garten Jr, Charles T

2011-01-01

Carbon stocks, and C:N ratios, were measured in the forest floor, mineral soil, and two mineral soil fractions (particulate and mineral-associated organic matter, POM and MOM, respectively) at five forest sites, ranging from 60 to 100 years old, along a latitudinal gradient in the eastern United States. Sampling at four sites was replicated over two consecutive years. For many measurements (like forest floor carbon stocks, cumulative soil organic carbon stocks to 20 cm, and the fraction of whole soil carbon in POM), there was no significant difference between years at each site despite the use of somewhat different sampling methods.more » With one exception, forest floor and mineral soil carbon stocks increased from warm, southern, sites (with fine-textured soils) to northern, cool, sites (with more coarse-textured soils). The exception was a northern site, with less than 10% silt-clay content, that had a soil organic carbon stock similar to those measured at southern sites. Soil carbon at each site was partitioned into two pools (labile and stable) on the basis of carbon measured in the forest floor and POM and MOM fractions from the mineral soil. A two-compartment steady-state model, with randomly varying parameter values, was used in probabilistic calculations to estimate the turnover time of labile soil organic carbon (MRTU) and the annual transfer of labile carbon to stable carbon (k2) at each site in two different years. Based on empirical data, the turnover time of stable soil carbon (MRTS) was determined by mean annual temperature and increased from 30 to 100 years from south to north. Moving from south to north, MRTU increased from approximately 5 to 14 years. Consistent with prior studies, 13C enrichment factors ( ) from the Rayleigh equation, that describe the rate of change in 13C through the soil profile, were an indicator of soil carbon turnover times along the latitudinal gradient. Consistent with its role in stabilization of soil organic carbon, silt-clay content along the gradient was positively correlated (r = 0.91; P 0.001) with parameter k2. Mean annual temperature was indicated as the environmental factor most strongly associated with south to north differences in the storage and turnover of labile soil carbon. However, soil texture appeared to override the influence of temperature when there was too little silt-clay content to stabilize labile soil carbon and thereby protect it from decomposition. Irrespective of latitudinal differences in measured soil carbon stocks, each study site had a relatively high proportion of labile soil carbon (approximately 50% of whole soil carbon to a depth of 20 cm). Depending on unknown temperature sensitivities, large labile pools of forest soil carbon are potentially at risk of depletion by decomposition in a warming climate, and losses could be disproportionately higher from coarse textured forest soils.« less

Quantifying Fire's Impacts on Total and Pyrogenic Carbon Stocks in Mixed-Conifer Forests: Results from Pre- and Post-Fire Measurements in Active Wildfire Incidents

NASA Astrophysics Data System (ADS)

Miesel, J. R.; Reiner, A. L.; Ewell, C. M.; Sanderman, J.; Maestrini, B.; Adkins, J.

2016-12-01

Widespread US fire suppression policy has contributed to an accumulation of vegetation in many western forests relative to historic conditions, and these changes can exacerbate wildfire severity and carbon (C) emissions. Serious concern exists about positive feedbacks between wildfire emissions and global climate; however, fires not only release C from terrestrial to atmospheric pools, they also create "black" or pyrogenic C (PyC) which contributes to longer-term C stability. Our objective was to quantify wildfire impacts on aboveground and belowground total C and PyC stocks in California mixed-conifer forests. We worked with incident management teams to access five active wildfires to establish and measure plots within days before and after fire. We measured pre- and post-fire aboveground forest structure and woody fuels to calculate aboveground biomass, biomass C, and PyC, and we collected pre- and post-fire forest floor and 0-5 cm mineral soil samples to measure belowground C and PyC stocks. Our preliminary results show that fire had minimal impact on the number of trees per hectare, whereas C losses from the tree layer occurred via consumption of foliage, and PyC gain occurred in tree bark. Fire released 54% to 100% of surface fuel C. In the forest floor layer, we observed 33 to 100% C loss, whereas changes in PyC stocks ranged from 100% loss to 186% gain relative to pre-fire samples. In general, fire had minimal to no impact on 0-5 cm mineral soil C. We will present relationships between total C, PyC and post-fire C and N dynamics in one of the five wildfire sites. Our data are unique because they represent nearly immediate pre- and post-fire measurements in major wildfires in a widespread western U.S. forest type. This research advances understanding of the role of fire on forest C fluxes and C sequestration potential as PyC.

Understory vegetation and site factors : implications for a managed Wisconsin landscape

Treesearch

K.D. Brosofske; J. Chen; Thomas R. Crow

2001-01-01

We investigated relationships between edaphic and environmental factors (soil, forest floor, topography, and canopy) and understory vegetation (composition, richness, and Shannon-Wiener diversity index, H')among 77 plots representing seven major patch types comprising a landscape in northern Wisconsin that has a long history of human management. Sampled patch...

Changes in forest floor and soil nutrients in a mixed oak forest 33 years after stem only and whole-tree harvest

Treesearch

D.W. Johnson; C.C. Trettin; D.E. Todd

2016-01-01

Vegetation, forest floor, and soils were resampled at a mixed oak site in eastern Tennessee that had been subjected to stem only (SOH), whole-tree harvest (WTH), and no harvest (REF) 33 years previously. Although differences between harvest treatments were not statistically significant (P < 0.05), average diameter, height, basal...

Chemical characteristics and acidity of soluble organic substances from a northern hardwood forest floor, central Maine, USA

NASA Astrophysics Data System (ADS)

Vance, George F.; David, Mark B.

1991-12-01

Our understanding of the chemistry, structure, and reactions of organic substances in forest floor leachates is limited and incomplete. Therefore, we examined the organic and inorganic chemistry of forest floor leachates collected from a hardwood forest in central Maine over a two-year period (1987-1989), including detailed study of dissolved organic carbon (DOC). Seasonal variations in NH 4+, NO 3-, K +, and total Al were believed due to organic matter decomposition and release. Leaching of other base cations closely followed that of NO 3-. Snowmelt resulted in NO 3- levels that decreased in time due to flushing of mineralization/nitrification by-products that had accumulated during the winter months. Total DOC ranged from 2228 to 7193 μmol L -1 with an average of 4835 μmol L -1. Monosaccharides and polyphenols constituted 3.9% (range of 3.4 to 4.4%) and 3.0% (2.2 to 3.7%) of the DOC, respectively, which suggests DOC may contain partially oxidized products that are possibly of a lignocellulose nature. Fractionation of the forest floor DOC indicated high organic acid contents (hydrophobic and hydrophilic acids) that averaged 92% of the total DOC. Organic acids were isolated and analyzed for elemental content (C, H, N, and S), and determination of UV absorptivity ( E 4/E 6) ratios, CuO oxidation products, FT-IR and 13C-NMR spectra, and acidity by potentiometric titration. Results from these analyses indicate the organic acids in the forest floor leachates are similar to fulvic acids. Hydrophobic and hydrophilic acids had average exchange acidities of 0.126 and 0.148 μeq μmol -1 C, respectively, and pKa, of 4.23 and 4.33. Their FT-IR and 13C-NMR spectra suggest they are primarily carboxylic acids, with aliphatic and aromatic structure. An organic charge contribution model was developed using titration data, DOC fractionation percentages, and the total DOC in the forest floor leachates. Application of the model to all solutions accounted for 97% of the charge balance deficits. Adjusted values for the flux of C and organic acidity due to organic solutes in forest floor leachates indicated translocation of 112 to 260 kg C ha -1 yr -1 and 460 to 1330 eq ha -1 yr -1, respectively, to the underlying mineral subsurface horizons.

Large sample area and size are needed for forest soil seed bank studies to ensure low discrepancy with standing vegetation.

PubMed

Shen, You-xin; Liu, Wei-li; Li, Yu-hui; Guan, Hui-lin

2014-01-01

A large number of small-sized samples invariably shows that woody species are absent from forest soil seed banks, leading to a large discrepancy with the seedling bank on the forest floor. We ask: 1) Does this conventional sampling strategy limit the detection of seeds of woody species? 2) Are large sample areas and sample sizes needed for higher recovery of seeds of woody species? We collected 100 samples that were 10 cm (length) × 10 cm (width) × 10 cm (depth), referred to as larger number of small-sized samples (LNSS) in a 1 ha forest plot, and placed them to germinate in a greenhouse, and collected 30 samples that were 1 m × 1 m × 10 cm, referred to as small number of large-sized samples (SNLS) and placed them (10 each) in a nearby secondary forest, shrub land and grass land. Only 15.7% of woody plant species of the forest stand were detected by the 100 LNSS, contrasting with 22.9%, 37.3% and 20.5% woody plant species being detected by SNLS in the secondary forest, shrub land and grassland, respectively. The increased number of species vs. sampled areas confirmed power-law relationships for forest stand, the LNSS and SNLS at all three recipient sites. Our results, although based on one forest, indicate that conventional LNSS did not yield a high percentage of detection for woody species, but SNLS strategy yielded a higher percentage of detection for woody species in the seed bank if samples were exposed to a better field germination environment. A 4 m2 minimum sample area derived from power equations is larger than the sampled area in most studies in the literature. Increased sample size also is needed to obtain an increased sample area if the number of samples is to remain relatively low.

Invasive and exotic earthworms: an unaccounted change to mercury cycling in northeastern US forest soils

NASA Astrophysics Data System (ADS)

Richardson, J. B.; Friedland, A. J.; Görres, J. H.; Renock, D. J.; Jackson, B. P.

2014-12-01

Invasive and exotic earthworms are now present in many forested areas of the northeastern US with currently unquantified consequences to abiotic and biotic Hg cycling. To quantify these effects, we measured Hg concentrations (mg kg-1) and amounts (μg m-2) in earthworms and soil horizons at 45 soil pits from 9 sites in northern New England. Seven earthworm species were observed in varying assemblages. Most earthworm species attained concentrations of Hg potentially hazardous to wildlife that may ingest them, with highest concentrations found in shallow-burrowing, litter-feeders. Specifically, Aporrectodea rosea and Amynthas agrestis had the greatest Hg concentrations (0.9 ± 0.1) and Hg amounts (8 ± 2) μg m-2. Aporrectodea rosea and Amynthas agrestis were found to inhabit the forest floor and the top 5 cm of the mineral horizons in high abundance, potentially making it a readily accessible prey species. Bioaccumulation of Hg by invasive and exotic earthworms may be an important mechanism that transfers Hg to ground foraging predators, such as thrushes, red-backed salamanders and foxes, which is generally unaccounted for in terrestrial food chains. Earthworm Hg concentrations were poorly correlated with their respective soil Hg concentrations, suggesting a species dependence for Hg bioaccumulation rather than site effects. We observed that forest floor Hg concentrations and amounts were 23% and 57% lower, respectively, at soil pits with earthworms compared to those without. Moreover, Hg amounts in forest floor-feeding earthworms exceeded the remaining forest floor Hg pools. Mercury concentrations and pools in the mineral soil were 21% and 33% lower, respectively, for soil pits with earthworms compared to those without. We hypothesize that enhanced decomposition, horizon disturbance and bioaccumulation by earthworms has decreased Hg amounts in the forest floor and mineral soil. Our results suggest that earthworms are decreasing Hg storage in forest soils with potential hazardous impacts for predatory animals in northeastern US forests and other ecosystems.

Nitrogen cycling in canopy soils of tropical montane forests responds rapidly to indirect N and P fertilization.

PubMed

Matson, Amanda L; Corre, Marife D; Veldkamp, Edzo

2014-12-01

Although the canopy can play an important role in forest nutrient cycles, canopy-based processes are often overlooked in studies on nutrient deposition. In areas of nitrogen (N) and phosphorus (P) deposition, canopy soils may retain a significant proportion of atmospheric inputs, and also receive indirect enrichment through root uptake followed by throughfall or recycling of plant litter in the canopy. We measured net and gross rates of N cycling in canopy soils of tropical montane forests along an elevation gradient and assessed indirect effects of elevated nutrient inputs to the forest floor. Net N cycling rates were measured using the buried bag method. Gross N cycling rates were measured using (15) N pool dilution techniques. Measurements took place in the field, in the wet and dry season, using intact cores of canopy soil from three elevations (1000, 2000 and 3000 m). The forest floor had been fertilized biannually with moderate amounts of N and P for 4 years; treatments included control, N, P, and N + P. In control plots, gross rates of NH4 (+) transformations decreased with increasing elevation; gross rates of NO3 (-) transformations did not exhibit a clear elevation trend, but were significantly affected by season. Nutrient-addition effects were different at each elevation, but combined N + P generally increased N cycling rates at all elevations. Results showed that canopy soils could be a significant N source for epiphytes as well as contributing up to 23% of total (canopy + forest floor) mineral N production in our forests. In contrast to theories that canopy soils are decoupled from nutrient cycling in forest floor soil, N cycling in our canopy soils was sensitive to slight changes in forest floor nutrient availability. Long-term atmospheric N and P deposition may lead to increased N cycling, but also increased mineral N losses from the canopy soil system. © 2014 John Wiley & Sons Ltd.

Leaf litter dynamics and nitrous oxide emission in a Mediterranean riparian forest: implications for soil nitrogen dynamics.

PubMed

Bernal, S; Butturini, A; Nin, E; Sabater, F; Sabater, S

2003-01-01

Mediterranean riparian zones can experience severe drought periods that lead to low soil moisture content, which dramatically affects their performance as nitrate removal systems. In the Mediterranean riparian zone of this study, we determined that N2O emission was practically nil. To understand the role of forest floor processes in nitrogen retention of a Mediterranean riparian area, we studied leaf litter dynamics of two tree species, London planetree [Platanus x acerifolia (Aiton) Willd.] and alder [Alnus glutinosa (L.) Gaertn.], for two years, along with soil nitrogen mineralization rates. Annual leaf litter fall equaled 562.6 +/- 10.1 (standard error) g dry wt. m(-2), 68% of which was planetree and 32% of which was alder. The temporal distribution of litterfall showed a two-peak annual cycle, one occurring in midsummer, the other in autumn. Planetree provided the major input of organic nitrogen to the forest floor, and the amount of planetree leaves remaining on the forest floor was equivalent to approximately four years of stock. Leaf litter decomposition was three times higher for alder (decay coefficient [k] = 1.13 yr(-1)) than for planetree (k = 0.365 yr(-1)). Mineralization rates showed a seasonal pattern, with the maximum rate in summer (1.92 mg N kg(-1) d(-1)). Although the forest floor was an important sink for nitrogen due to planetree leaf accumulation, 7.5% of this leaf litter was scoured to the streambed by wind. This loss was irrelevant for alder leaves. Due to the litter quality, the forest floor of this Mediterranean riparian forest acts as a nitrogen sink.

78 FR 72914 - Changes in Flood Hazard Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-04

.... Forest Hill, Hill, TX 76119. 3219 California Parkway, Forest Hill, TX 76119. Travis City of Austin (13..., Austin, TX Road, 12th 78767. Floor, Austin, TX 78704. Travis Unincorporated The Honorable Travis County..., 700 Austin, TX 78767. Lavaca Street, 5th Floor, Suite 540, Austin, TX 78701. Williamson City of...

Forest floor and mineral soil respiration rates in a northern Minnesota red pine chronosequence

Treesearch

Matthew Powers; Randall Kolka; John Bradford; Brian Palik; Martin Jurgensen

2017-01-01

We measured total soil CO2 efflux (RS) and efflux from the forest floor layers (RFF) in red pine (Pinus resinosa Ait.) stands of different ages to examine relationships between stand age and belowground C cycling. Soil temperature and RS were often lower in...

Throughfall Monitoring Of Old Growth, Second Growth, And Cleared Vegetation Plots On Prince of Wales Island, Alaska

NASA Astrophysics Data System (ADS)

Prussian, K. M.

2006-12-01

The density of forest canopy affects the amount of rain reaching the forest floor in forested environments of Southeast Alaska. Less throughfall occurs in the second growth sites than in the old growth site and greater throughfall occurs in the clear-cut sites. More specifically, preliminary data show that SG sites received between 38 and 87% of the OG throughfall and the clear-cut sites experienced between 145 and 248% of the OG throughfall. Precipitation gages were used to monitor throughfall in each of the forested vegetation sites on Prince of Wales Island, Alaska, as an indicator of the amount of water reaching the forest floor in these different forest types. Data collected during 2004 and 2005 included 23 storms ranging from 0.2 to 10.6 inches of rain in the clear-cut forest. This monitoring is an effort to determine the affect, if any, that forest management could have on throughfall, and furthermore, lend information to forest management effects on the water balance within a watershed. Site selection focused on similarities in location, elevation, aspect, and accessibility while accounting for the three varying vegetation conditions. Data collected during 2004 and 2005 sampling seasons were in the same sampling plots, while data collected in 2006 is a duplicate set of sites. Twenty-three storms were used to determine the affect, if any, that forest management could have on throughfall, and furthermore, lend information to forest management effects on the water balance within a watershed. The second growth stand was harvested in 1979 and is currently in stem re-initiation phase with thick conifer regeneration. The clear-cut site was harvested in 1999 and contains conifer vegetation, blueberry, and salmonberry vegetation less than five feet in height. Storms were defined as events that were clearly delineated by lack of rainfall for a period of time, or similar antecedent conditions, and totaled at least .2 inches of rain at the CC site. Analysis of a storm event began prior to rainfall (in the CC site) and terminated post throughfall in the SG sites.

[Species composition and diversity of soil mesofauna in the 'Holy Hills' fragmentary tropical rain forest of Xishuangbanna, China].

PubMed

Yang, X; Sha, L

2001-04-01

The species composition and diversity of soil mesofauna were examined in fragmented dry tropical seasonal rainforest of tow 'Holy Hills' of Dai nationality, compared with the continuous moist tropical seasonal rain forest of Nature Reserve in Xishuangbanna area. 5 sample quadrats were selected along the diagonal of 20 m x 20 m sampling plot, and the samples of litterfall and 0-3 cm soil were collected from each 50 cm x 10 cm sample quadrat. Animals in soil sample were collected by using dry-funnel(Tullgren's), were identified to their groups according to the order. The H' index, D.G index and the pattern of relative abundance of species were used to compare the diversity of soil mesofauna. The results showed that the disturbance of vegetation and soil resulted by tropical rainforest fragmentation was the major factor affecting the diversity of soil mesofauna. Because the fragmented forest was intruded by some pioneer tree species and the "dry and warm" effect operated, this forest had more litterfall on the floor and more humus in the soil than the continuous moist rain forest. The soil condition with more soil organic matter, total N and P, higher pH value and lower soil bulk density became more favorable to the soil mesofauna. Therefore, the species richness, abundance and diversity of soil mesofauna in fragmented forests were higher than those in continuous forest, but the similarity of species composition in fragmented forest to the continuous forest was minimal. Soil mesofauna diversity in fragmented forests did not change with decreasing fragmented area, indicating that there was no species-area effect operation in this forest. The pattern of relative abundance of species in these forest soils was logarithmic series distribution.

Effect of radiocesium transfer on ambient dose rate in forest environments affected by the Fukushima Nuclear Power Plant accident

NASA Astrophysics Data System (ADS)

Kato, H.

2015-12-01

We investigated the transfer of canopy-intercepted radiocesium to the forest floor during 3 years following the Fukushima Daiichi Nuclear Power Plant accident. The cesium-137 (Cs-137) contents in throughfall, stemflow, and litterfall were monitored in two coniferous stands (plantation of Japanese cedar) and a deciduous broad-leaved forest stand (Japanese oak with red pine). We also measured the ambient dose rate (ADR) at different heights in the forest using a survey meter and a portable Ge gamma-ray detector. Total Cs-137 deposition flux from the canopy to forest floor for the mature cedar, young cedar, and the mixed broad-leaved stands were 166 kBq/m2, 174 kBq/m2, and 60 kBq/m2, respectively. These values correspond to 38%, 40% and 13% of total atmospheric input after the accident. The ambient dose rate in forest exhibited height dependency and its vertical distribution varied with forest type and stand age. The ambient dose rate showed an exponential decrease with time for all the forest sites, however the decreasing trend differed depending on the height of dose measurement and forest type. The ambient dose rate at the canopy (approx. 10 m-height) decreased faster than that expected from physical decay of the two radiocesium isotopes, whereas those at the forest floor varied between the three forest stands. The radiocesium deposition via throughfall seemed to increase ambient dose rate during the first 200 days after the accident, however there was no clear relationship between litterfall and ambient dose rate since 400 days after the accident. These data suggested that the ambient dose rate in forest environment varied both spatially and temporally reflecting the transfer of radiocesium from canopy to forest floor. However, further monitoring investigation and analysis are required to determine the effect of litterfall on long-term trend of ambient dose rate in forest environments.

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.

A canopy trimming experiment in Puerto Rico: the response of litter invertebrate communities to canopy loss and debris deposition in a tropical forest subject to hurricanes

Treesearch

Barbara A. Richardson; Michael J. Richardson; Grizelle Gonzalez; Aaron B. Shiels; Diane S. Srivastava

2010-01-01

Hurricanes cause canopy removal and deposition of pulses of litter to the forest floor. A Canopy Trimming Experiment (CTE) was designed to decouple these two factors, and to investigate the separate abiotic and biotic consequences of hurricane-type damage and monitor recovery processes. As part of this experiment, effects on forest floor invertebrate communities were...

Rates of forest floor decomposition and nutrient turnover in aspen, pine, and spruce stands on two soils.

Treesearch

D. A. Perala; D.H. Alban

1982-01-01

Compares rates of forest floor decomposition and nutrient turnover in aspen and conifers. These rates were generally most rapid under aspen, slowest under spruce, and more rapid on a loamy fine sand than on a very fine sandy loam. Compares results with literature values.

Forest Floor CO2 Flux From Two Contrasting Ecosystems in the Southern Appalachians

Treesearch

James M. Vose; Barton D. Clinton; Verl Emrick

1995-01-01

We measured forest floor CO2 flux in two contrasting ecosystems (white pine plantation and northern hardwood ecosystems at low and high elevations, respectively) in May and September 1993 to quantify differences and determine factors regulating CO2 fluxes. An automated IRGA based, flow through system was used with chambers...

Impact of prescribed fire on understory and forest floor nutrients

Treesearch

Walter A. Hough

1981-01-01

The impact of low-intensity prescribed fires on slash pine/saw-palmetto/gallberry understory and forest floor nutrients was estimated from measurements before and after burning. Highly significant correlations existed between weight loss of these fuel components and the weight loss of several elements. Energy loss was also highly correlated with forestfloor and...

A TWO-PROBE METHOD FOR MEASURING WATER CONTENT OF THIN FOREST FLOOR LITTER LAYERS USING TIME DOMAIN REFLECTOMETRY

EPA Science Inventory

Few methods exist that allow non-destructive in situ measurement of the water content of forest floor litter layers (Oa,Oe, and Oi horizons). Continuous non-destructive measurement is needed in studies of ecosystem processes because of the relationship between physical structure ...

36 CFR 1192.79 - Floors, steps and thresholds.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Floors, steps and thresholds... Light Rail Vehicles and Systems § 1192.79 Floors, steps and thresholds. (a) Floor surfaces on aisles, step treads, places for standees, and areas where wheelchair and mobility aid users are to be...

Evidence for marine microfossils from amber.

PubMed

Girard, Vincent; Schmidt, Alexander R; Saint Martin, Simona; Struwe, Steffi; Perrichot, Vincent; Saint Martin, Jean-Paul; Grosheny, Danièle; Breton, Gérard; Néraudeau, Didier

2008-11-11

Amber usually contains inclusions of terrestrial and rarely limnetic organisms that were embedded in the places were they lived in the amber forests. Therefore, it has been supposed that amber could not have preserved marine organisms. Here, we report the discovery amber-preserved marine microfossils. Diverse marine diatoms as well as radiolarians, sponge spicules, a foraminifer, and a spine of a larval echinoderm were found in Late Albian and Early Cenomanian amber samples of southwestern France. The highly fossiliferous resin samples solidified approximately 100 million years ago on the floor of coastal mixed forests dominated by conifers. The amber forests of southwestern France grew directly along the coast of the Atlantic Ocean and were influenced by the nearby sea: shells and remnants of marine organisms were probably introduced by wind, spray, or high tide from the beach or the sea onto the resin flows.

Effect of O horizon and Forest Harvest Residue Manipulations on Soil Organic Matter Content and Composition of a Loblolly Pine Plantation in the Southeastern United States

NASA Astrophysics Data System (ADS)

Hatten, J.; Mack, J.; Dewey, J.; Sucre, E.; Leggett, Z.

2012-04-01

Forest harvest residues and forest floor materials are significant sources of mineral soil organic matter and nutrients for regenerating and establishing forests. Harvest residues in particular are occasionally removed, piled, or burned following harvesting. While the forest floor is never purposely removed during operational harvesting and site preparation, they could become in high demand as bioenergy markets develop. Weyerhaeuser Company established an experimental study to evaluate the effect of forest-floor manipulation on site productivity and soil carbon. This study was installed in a loblolly pine plantation near Millport, Alabama, USA on the Upper Gulf Coastal Plain to test both extremes from complete removal of harvest residues and forest floor to doubling of these materials. This study has been continuously monitored since its establishment in 1994. We have examined the effects of varying forest floor levels on the biomass, soil carbon content, and soil carbon composition in the context of these management activities. Above- and below-ground productivity, soil moisture, soil temperature, and nutrient dynamics have been related to soil organic carbon in mineral soil size/density fractionation and lignin and cutin biomarkers from the cupric oxide (CuO) oxidation technique. We have found that while removing litter and harvest residues has little effect on biomass production and soil carbon, importing litter and harvest residues increases forest productivity and soil carbon content. Interestingly, increased carbon was observed in all depths assessed (O horizon, 0-20, 20-40, and 40-60cm) suggesting that this practice may sequester organic carbon in deep soil horizons. Our biomarker analysis indicated that importing litter and harvest residues increased relative contributions from above ground sources at the 20-40cm depth and increased relative contributions from belowground sources at the 40-60cm depth. These results suggest that organic matter manipulations in managed forests can have significant effects on deep soil carbon that may be resistant to mineralization or the effects of other perturbations such as climate change.

Distribution, dispersal and abundance of hayscented fern spores in mixed hardwood stands

Treesearch

Larry H. McCormick; Kathy A. Penrod

1995-01-01

A study was conducted in 1992 to assess the abundance and distribution of viable hayscented fern spores in the forest floor of central Pennsylvania hardwood stands before and after seasonal spore dispersal. Intact soil samples were collected at various distances and directions from established fern communities and placed in a greenhouse to effect spore germination....

Input and output budgets of radiocesium concerning the forest floor in the mountain forest of Fukushima released from the TEPCO's Fukushima Dai-ichi nuclear power plant accident.

PubMed

Niizato, Tadafumi; Abe, Hironobu; Mitachi, Katsuaki; Sasaki, Yoshito; Ishii, Yasuo; Watanabe, Takayoshi

2016-09-01

Estimations of radiocesium input and output concerning the forest floor within a mountain forest region have been conducted in the north and central part of the Abukuma Mountains of Fukushima, northeast Japan, after a 2-3 year period following the TEPCO Fukushima Dai-ichi nuclear power plant accident. The radiocesium input and output associated with surface washoff, throughfall, stemflow, and litterfall processes at experimental plots installed on the forest floor of evergreen Japanese cedars and deciduous Konara oaks have been monitored. Despite the high output potential in the mountainous forest of Fukushima, the results at both monitoring locations show the radiocesium input to be 4-50 times higher than the output during the summer monsoon in Fukushima. These results indicate that the radiocesium tends to be preserved in the forest ecosystem due to extremely low output ratios (0.05%-0.19%). Thus, the associated fluxes throughout the circulation process are key issues for the projecting the environmental fate of the radiocesium levels, along with the subsequent reconstruction of life emphasized within the setting. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Longleaf pine site response to repeated fertilization and forest floor removal by raking and prescribed burning

Treesearch

Kim Ludovici; Robert Eaton; Stanley Zarnoch

2018-01-01

Removal of forest floor litter by pine needle raking and prescribed burning is a common practice in longleaf pine (Pinus palustris Mill.) stands on Coastal Plain sites in the Southeastern United States. Repeated removal of litter by raking and the loss of surface organic matter from controlled burns can affect the...

Explaining the apparent resiliency of loblolly pine plantation to organic matter removal

Treesearch

Jeff A. Hatten; Eric B. Surce; Zakiya Leggett; Jason Mack; Scott D. Roberts; Janet Dewey; Brian Strahm

2015-01-01

We utilized 15-year measurements from an organic matter manipulation experiment in a loblolly pine plantation in the Upper Coastal Plain of Alabama to examine the apparent resiliency of a loblolly pine stand to organic matter removal. Treatments included complete removal of harvest residues and forest floor (removed), doubling of harvest residues and forest floor (...

Temperatures below leaf litter during winter prescribed burns: implications for litter-roosting bats

Treesearch

Roger W. Perry; Virginia L. McDaniel

2015-01-01

Some bat species, including eastern red bats (Lasiurus borealis), roost for short periods beneath leaf litter on the forest floor during winter in the south-eastern USA, a region subjected to frequent fire. The variability in fuel consumption, the heterogeneous nature of burns, and the effects of litter and duff moisture on forest-floor...

Effects of a simulated hurricane disturbance on forest floor microbial communities

Treesearch

Sharon A. Cantrell; Marirosa Molina; D. Jean Lodge; Francisco J. Rivera-Figueroa; Maria Ortiz; Albany A. Marchetti; Mike J. Cyterski; José R. Pérez-Jiménez

2014-01-01

Forest floor microbial communities play a critical role in the processes of decomposition and nutrient cycling. The impact of cultivation, contamination, fire, and land management on soil microbial communities have been studied but there are few studies of microbial responses to the effects of tropical storms. The Canopy Trimming Experiment was executed in the Luquillo...

36 CFR 1192.99 - Floors, steps and thresholds.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Floors, steps and thresholds... Commuter Rail Cars and Systems § 1192.99 Floors, steps and thresholds. (a) Floor surfaces on aisles, step... shall be slip-resistant. (b) All thresholds and step edges shall have a band of color(s) running the...

76 FR 14898 - Daniel Boone National Forest Resource Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-18

... DEPARTMENT OF AGRICULTURE Forest Service Daniel Boone National Forest Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Daniel Boone National Forest... basement floor. Written comments should be sent to Kimberly Morgan, Daniel Boone National Forest, 1700...

[Microsite characteristics of pit and mound and their effects on the vegetation regeneration in Pinus koraiensis-dominated broadleaved mixed forest].

PubMed

Du, Shan; Duan, Wen-Biao; Wang, Li-Xia; Chen, Li-Xin; Wei, Quan-Shuai; Li, Meng; Wang, Li-dong

2013-03-01

Abstract: An investigation was conducted in a 2.55 hm2 plot of Pinus koraiensis-dominated broad-leaved mixed forest to study the microsite characteristics of pit and mound formed by 42 treefalls and the status of vegetation regeneration on the microsites. The soil water content, soil temperature, relative air humidity, and photosynthetically active radiation (PAR) on five microsites (mound top, mound face, pit wall, pit bottom, and intact forest floor) were measured. Among the five mirosites, mound top had the highest PAR (527.9 micromol.m-2.s-1 ) while intact forest floor had the lowest one (58.7 micromol.m-2.s-), mound top had the highest soil temperature (16.0 degrees C) but pit bottom had the lowest one (13.3 degrees C), pit bottom had the highest soil water content (34.6%) but mound face had the lowest one (0.5%), and intact forest floor had the highest relative air humidity (75.9%) but mound top had the lowest one (68.0%). The frequency of forming pit/ mound complex by the tree species was decreased in the order of Pinus koraiensis (42. 9%) >Picea asperata (31.0%) > Betula platyphylla (16.7%) > Abies fabri (7. 1%) > Prunus padus (2.4%). Among the 42 treefalls, two-thirds of them were in northwest direction. The treefalls volume had significant positive correlations with pit depth, pit length, mound height, and mound width, but negative correlation with mound thickness. The treefall mean diameter at breast height had significant positive correlations with pit width (r=0.328, P=0.017) and pit length (r=0.527, P= 0). The tree species richness at the microsites decreased in the order of intact forest floor > pit > mound, and the tree species coverage was in the sequence of intact forest floor > pit > mound.

Spatial interpolation and simulation of post-burn duff thickness after prescribed fire

Treesearch

Peter R. Robichaud; S. M. Miller

1999-01-01

Prescribed fire is used as a site treatment after timber harvesting. These fires result in spatial patterns with some portions consuming all of the forest floor material (duff) and others consuming little. Prior to the burn, spatial sampling of duff thickness and duff water content can be used to generate geostatistical spatial simulations of these characteristics....

Comparing jack pine slash and forest floor moisture contents and National Fire Danger Rating System predictions.

Treesearch

Robert M. Loomis; William A. Main

1980-01-01

Relations between certain slash and forest floor moisture contents and the applicable estimated time lag fuel moistures of the National Fire Danger Rating System were investigated for 1-year-old jack pine fuel types in northeastern Minnesota and central Lower Michigan. Only approximate estimates of actual fuel moisture are possible fore the relations determined, thus...

Viability of litter-stored Pinus taeda L. seeds after simulated prescribed winter burns

Treesearch

Michael D. Cain; Michael G. Shelton

1998-01-01

Stratified loblolly pine (Pinus taeda L.) seeds were placed at three depths in a reconstructed forest floor and subjected to simulated prescribed winter burns. Within the forest floor, pine seeds were placed at the L/upper-F interface, upper-F/lower-F interface, and lower-F/mineral-soil interface. Wind was generated by electric box-fans. Seeds that...

Variation in soil and forest floor characteristics along gradients of ericaceous, evergreen shrub cover in the southern Appalachians

Treesearch

Jonatha L. Horton; Barton D. Clinton; John F. Walker; Colin M. Beir; Erik T. Nilsen

2009-01-01

Ericaceous shrubs can influence soil properties in many ecosystems. In this study, we examined how soil and forest floor properties vary among sites with different ericaceous evergreen shrub basal area in the southern Appalachian mountains. We randomly located plots along transects that included open understories and understories with varying amounts of Rhododendron...

Viability of litter-stored Quercus falcata Michx. acorns after simulated prescribed winter burns

Treesearch

Michael D. Cain; Michael G. Shelton

1998-01-01

Partially stratified (11 days) southern red oak (Quercus falcata Michx.) acorns were placed at three depths in a reconstructed forest floor and subjected to simulated prescribed winter burns. Within the forest floor, acorns were placed within the L layer, at the upper-F/ lower-F interface, and at the lower-F/mineral-soil interface. Winds for a...

36 CFR 1192.117 - Floors, steps and thresholds.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Floors, steps and thresholds... Intercity Rail Cars and Systems § 1192.117 Floors, steps and thresholds. (a) Floor surfaces on aisles, step.... (b) All step edges and thresholds shall have a band of color(s) running the full width of the step or...

Forest floor community metatranscriptomes identify fungal and bacterial responses to N deposition in two maple forests

DOE PAGES

Hesse, Cedar N.; Mueller, Rebecca C.; Vuyisich, Momchilo; ...

2015-04-23

Anthropogenic N deposition alters patterns of C and N cycling in temperate forests, where forest floor litter decomposition is a key process mediated by a diverse community of bacteria and fungi. To track forest floor decomposer activity we generated metatranscriptomes that simultaneously surveyed the actively expressed bacterial and eukaryote genes in the forest floor, to compare the impact of N deposition on the decomposers in two natural maple forests in Michigan, USA, where replicate field plots had been amended with N for 16 years. Site and N amendment responses were compared using about 74,000 carbohydrate active enzyme transcript sequences (CAZymes)more » in each metatranscriptome. Parallel ribosomal RNA (rRNA) surveys of bacterial and fungal biomass and taxonomic composition showed no significant differences in either biomass or OTU richness between the two sites or in response to N. Site and N amendment were not significant variables defining bacterial taxonomic composition, but they were significant for fungal community composition, explaining 17 and 14% of the variability, respectively. The relative abundance of expressed bacterial and fungal CAZymes changed significantly with N amendment in one of the forests, and N-response trends were also identified in the second forest. Although the two ambient forests were similar in community biomass, taxonomic structure and active CAZyme profile, the shifts in active CAZyme profiles in response to N-amendment differed between the sites. One site responded with an over-expression of bacterial CAZymes, and the other site responded with an over-expression of both fungal and different bacterial CAZymes. Both sites showed reduced representation of fungal lignocellulose degrading enzymes in N-amendment plots. The metatranscriptome approach provided a holistic assessment of eukaryote and bacterial gene expression and is applicable to other systems where eukaryotes and bacteria interact.« less

Carbon and Nitrogen dynamics in forest soils depending on light conditions and tree species

NASA Astrophysics Data System (ADS)

Veselinovic, Bojana; Hager, Herbert

2013-04-01

Climate change mitigation actions under the Kyoto Protocol apply among other decreases of CO2-emissions and/or increases of carbon (C) stocks. As soils represent the second biggest C-reservoir on Earth, an exact estimation of the stocks and reliable knowledge on C-dynamics in forest soils is of high importance. Anyhow, here, the accurate GHG-accounting, emission reductions and increase in C stocks is hampered due to lack of reliable data and solid statistical methods for the factors which influence C-sequestration in and its release from these systems. In spite of good progress in the scientific research, these factors are numerous and diverse in their interactions. This work focuses on influence of the economically relevant tree species - Picea abies, Fagus sylvatica and Quercus spp. - and light conditions on forest floor and mineral soil C and N dynamics in forest soils. Spruce monocultures have been widely used management practices in central European forests during the past century. Such stands are in lower altitudes and on heavy and water logged soils unstable and prone to disturbances, especially to windthrows. We hypothesize that windthrow areas loose C & N and that the establishment of the previous nutrient stocks is, if at all, only possible to be reached over the longer periods of time. We research also how the increased OM depletion affects the change of C & N stocks in forest floor vs. mineral soil. Conversion of such secondary spruce monocultures to site adequate beech and oak forests may enable higher stocks allocated predominantly as stable organic carbon and as plant available nitrogen. For this purpose sites at 300-700 m altitude with planosols were chosen in the region of the Northern Alpine Foothills. A false chronosequence approach was used in order to evaluate the impacts of the tree species and change in light conditions on dynamic of C & N in the forest floor and mineral soil, over the period 0-100 (for oak 120 y.) years. The C- and N-pools were estimated for different compartments over the available age classes. The sampling of humus and surface vegetation was done using 30x30 and 50x50 cm frame. It was distinguished between following fractions: fine/coarse roots ( than 2 mm), woody debris (dead wood, branches, cones and acorns), living vegetation (ground vegetation and its roots), litter (leaves fresh and decomposed coarse organic layer) and humus (more than 30% of fine organic matter). C and N stocks in mineral soil were assessed for the 10, 30 and 60 cm depth. Furthermore, the influence of solar radiation on humus and mineral soil C and N was evaluated using the GSF (global site factor) estimated with hemispherical photography. The photographs were taken on each sampling point using the 180_ viewing angle looking upward into the canopy. As expected, the solar energy strongly influences the occurrence of herbaceous layer in spruce and oak stands. Furthermore, beech and oak chronosequences display positive (although not strong) correlation between the light factor and C & N accumulation in the humus fractions. In the beech chronosequence, good correlation with light conditions in stands is only found in the sum of all forest floor compartments (litter, woody debris and humus). On the contrary, with exception of spruce (r = 0.391** for the 10 cm depth) no significant correlation was found with the mineral soil C for the three observed depths. depths.

A new mechanism for calcium loss in forest-floor soils

USGS Publications Warehouse

Lawrence, G.B.; David, M.B.; Shortle, W.C.

1995-01-01

CALCIUM is the fifth most abundant element in trees, and is an essential component for wood formation and the maintenance of cell walls. Depletion of Ca from the rooting zone can result in acidification of soil1 and surface water2 and possibly growth decline and dieback of red spruce3,4. During the past six decades, concentrations of root-available Ca (exchangeable and acid-ex tract able forms) in forest-floor soils have decreased in the northeastern United States5,6. Both net forest growth and acid deposition have been put forth as mechanisms that can account for this Ca depletion5,6. Here, however, we present data collected in red spruce forests in the northeastern United States that are inconsistent with either of these mechanisms. We propose that aluminium, mobilized in the mineral soil by acid deposition, is transported into the forest floor in a reactive form that reduces storage of Ca, and thus its availability for root uptake. This results in potential stress to trees and, by increasing the demand for Ca, also decreases neutralization of drainage waters, thereby leading to acidification of lakes and streams.

Increasing Soil Calcium Availability Alters Forest Soil Carbon Stocks

NASA Astrophysics Data System (ADS)

Melvin, A.; Goodale, C. L.

2011-12-01

Acid deposition in the Northeastern U.S. has been linked to a loss of soil base cations, especially calcium (Ca). While much research has addressed the effects of Ca depletion on soil and stream acidification, few studies have investigated its effects on ecosystem carbon (C) balance. We studied the long-term effects of increased Ca availability on C cycling in a northern hardwood forest in the Adirondack Park, NY. In 1989, calcium carbonate (lime) was added to ~ 100 ha of the Woods Lake Watershed to ameliorate the effects of soil Ca depletion. An additional 100 ha were maintained as controls. We hypothesized that the lime addition would improve forest health and that this improvement would be evident in increased tree biomass, leaf litter, and fine root production. Within the forest floor, we anticipated that the increased pH associated with liming would stimulate microbial activity resulting in increased decomposition and basal soil respiration, and reduced C stocks. Additionally, we hypothesized that increased Ca availability could enhance Ca-OM complexation in the upper mineral soils, leading to increased C stocks in these horizons. Eighteen years after liming, soil pH and exchangeable Ca pools remained elevated in the forest floor and upper mineral soil of the limed plots. Forest floor C stocks were significantly larger in limed plots (68 vs. 31 t C ha-1), and were driven primarily by greater C accumulation in the forest floor Oa horizon. Mineral soil C stocks did not differ between limed and control soils. Liming did not affect tree growth, however a net decline in biomass was observed across the entire watershed. There was a trend for larger fine root and foliar litter inputs in limed plots relative to controls, but the observed forest floor accumulation appears to be driven primarily by a suppression of decomposition. Liming reduced basal soil respiration rates by 17 and 43 % in the Oe and Oa horizons, respectively. This research suggests that Ca may stabilize soil organic matter and that long-term Ca depletion caused by acid deposition could have large, unexpected effects on ecosystem C dynamics.

Fire Ecology of Seeds from Rubus Spp.: A Competitor During Natural Pine Regeneration

Treesearch

Michael D. Cain; Michael G. Shelton

1999-01-01

Air-dried blackbeny (Rubus spp.) fruits were placed at three depths in a reconstructed forest floor and subjected to a simulated prescribed summer bum. Within the forest floor, fruits were placed on the L layer, at the upper-F/lower-F interface, and at the lower-F/mineral-soil interface. Wind for a headfire was generated by electric boxfans....

Acute physiological stress and mortality following fire in a long-unburned longleaf pine ecosystem

Treesearch

J.J. O’Brien; J.K. Hiers; R.J. Mitchell; J.M. Varner; K. Mordecai

2010-01-01

One important legacy of fire exclusion in ecosystems dependent upon frequent fire is the development of organic soil horizons (forest floor) that can be colonized by fine roots. When fire is re-introduced, the forest floor is often consumed by fire and heavy overstory mortality, often delayed by months, results. We hypothesized that the delayed post-fire tree mortality...

Seeing the Landscape and the Forest Floor: Changes Made to Improve the Connectivity of Concepts in a Hybrid Problem-Based Learning Curriculum

ERIC Educational Resources Information Center

O'Neill, Geraldine; Hung, Woei

2010-01-01

Problem-based learning (PBL) curricula utilise authentic problems that are based in the real-world of practice. This very characteristic enables students to develop an intimate knowledge about the intricacies of practice, metaphorically, seeing the details of the forest floor. However, it is equally important for students to develop an overall…

Soil ploughing for forest regeneration leads to changes in carbon decomposition - a case study with stable isotopes

NASA Astrophysics Data System (ADS)

Stróżecki, Marcin; Silvennoinen, Hanna; Strzeliński, Paweł; Chojnicki, Bogdan Heronim

2018-04-01

It is important to quantify carbon decomposition to assess the reforestation impact on the forest floor C stocks. Estimating the loss of C stock in a short-term perspective requires measuring changes in soil respiration. This is not trivial due to the contribution of both soil microbes and vegetation to the measured CO2 flux. However, C stable isotopes can be used to partition the respiration and potentially to assess how much of the recalcitrant C stock in the forest floor is lost. Here, we measured the soil respiration at two forest sites where different regeneration methods were applied, along with an intact forest soil for reference. In so doing, we used a closed dynamic chamber for measuring respiration and the 13C composition of the emitted CO2. The chamber measurements were then supplemented with the soil organic carbon analysis and its δ13C content. The mean δ13C-CO2 estimates for the source of the CO2 were -26.4, -27.9 and -29.5‰, for the forest, unploughed and ploughed, respectively. The 13C of the soil organic carbon did, not differ significantly between sites. The higher soil respiration rate at the forest, as compared to the unploughed site, could be attributed to the autotrophic respiration by the forest floor vegetation.

Anthropogenic effects on a tropical forest according to the distance from human settlements.

PubMed

Popradit, Ananya; Srisatit, Thares; Kiratiprayoon, Somboon; Yoshimura, Jin; Ishida, Atsushi; Shiyomi, Masae; Murayama, Takehiko; Chantaranothai, Pranom; Outtaranakorn, Somkid; Phromma, Issara

2015-10-05

The protection of tropical forests is one of the most urgent issues in conservation biology because of the rapid deforestation that has occurred over the last 50 years. Even in protected forests, the anthropogenic effects from newly expanding villages such as harvesting of medicinal plants, pasturing cattle and forest fires can induce environmental modifications, especially on the forest floor. We evaluated the anthropogenic effects of the daily activities of neighboring residents on natural forests in 12 plots extending from the village boundary into a natural forest in Thailand. The basal area per unit land area did not present a significant trend; however, the species diversity of woody plants decreased linearly towards the village boundary, which caused a loss of individual density because of severe declines in small saplings compared with adult trees and large saplings in proximity to the village. An analysis of tree-size categories indicates a lack of small samplings near the village boundary. The current forest appears to be well protected based on the adult tree canopy, but regeneration of the present-day forests is unlikely because of the loss of seedlings.

Deep Soil Carbon Influenced Following Forest Organic Matter Manipulation In A Loblolly Pine Plantation In The Southeastern United States

NASA Astrophysics Data System (ADS)

Hatten, J. A.; Mack, J.; Sucre, E.; Leggett, Z.; Roberts, S.; Dewey, J.

2013-12-01

Forest harvest residues and forest floor materials are significant sources of mineral soil organic matter and nutrients for regenerating and establishing forests. Harvest residues in particular are occasionally removed, piled, or burned following harvesting. Weyerhaeuser Company established an experimental study to evaluate the effect of the removal and addition of harvest residual and forest-floor on site productivity and soil carbon. This study was installed in a loblolly pine plantation near Millport, Alabama, USA on the Upper Gulf Coastal Plain to test both extremes from complete removal of harvest residues and forest floor to doubling of these materials. This study has been continuously monitored since its establishment in 1994. We have examined the effects of varying forest floor levels on the biomass, soil carbon content, and soil carbon composition in the context of these management activities. Above- and below-ground productivity, soil moisture, soil temperature, and nutrient dynamics have been related to soil organic carbon in mineral soil, size/density fractionation, and lignin and cutin biomarkers from the cupric oxide (CuO)-oxidation technique. We have found that while removing litter and harvest residues has little effect on biomass production and soil carbon, importing litter and harvest residues increases forest productivity and soil carbon content. Interestingly, increased carbon was observed in all depths assessed (O horizon, 0-20, 20-40, and 40-60cm) suggesting that this practice may sequester organic carbon in deep soil horizons. Our biomarker analysis indicated that importing litter and harvest residues increased relative contributions from above ground sources at the 20-40cm depth and increased relative contributions from belowground sources at the 40-60cm depth. These results suggest that organic matter manipulations in managed forests can have significant effects on deep soil carbon that may be resistant to mineralization or the effects of other perturbations such as climate change.

Carbon and nitrogen dynamics of soil and litter along an altitudinal gradient in Atlantic Forest

NASA Astrophysics Data System (ADS)

Piccolo, M. D.; Martins, S. C.; Camargo, P. B.; Carmo, J. B.; Sousa Neto, E.; Martinelli, L. A.

2008-12-01

The Ombrophylus Dense Forest or Atlantic Forest is the second most important Biome in extension of Brazil, and it is considered a hot-spot in terms of biodiversity. It is localized in Brazilian Coast, and it covered originally 1.2 million km2, but currently only 8% of the original forest remains. The study was carried out in Sao Paulo State, Brazil (23° 24' S and 45° 11' W). The studied areas were: Restinga Vegetation (RV), 5 m above sea level; Low Altitude Ombrophylus Dense Forest (LAODF), 100 m asl; Submontane Ombrophylus Dense Forest (SODF), 600m asl and; Montane Ombrophylus Dense Forest (MODF), 1000 m asl. The aim of this study was to evaluate the effect of altitudinal gradient, with specific phytophysiognomies, on C and N dynamics in the soil and litter at Atlantic Forest. A sampling area of 1 ha was subdivided in contiguous sub- parcels (10 x 10 m). The forest floor litter accumulated (0.06 m2) was collected monthly (n=60), during 12 months, in each phytophysiognomies. Soils samples (0-0.05m depth) were collected (n=32) from square regular grids, 30 m away from each other. Changes in litter contents of C and N were not detected along the altitudinal gradient, and the values observed were 400 and 15g kg-1 for C and N, respectively. Litter ä13C values did not change significantly with the altitudinal gradient and were represented by C3 plants values. The C and N stocks were high in the clay soils (LAODF, SODF and MODF) when compared to sandy soil (RV). The soil C stocks (24 to 30 Mg ha-1) were similar among the altitudinal gradients, except RV (16 Mg ha-1). The areas of elevated altitude (MODF and SODF) showed high N stocks (2.3 Mg ha-1), followed by LAODF (1.8Mg ha-1) and RV (0.9Mg ha-1). In all altitudes there was 13C enrichment with soil depth, and it can be explained by the different fractions of the organic matter distributed along the soil profile, and also due the effect of the isotopic dilution between the forest floor litter and the soil.

Eco-hydrological Controls on Litter Moisture Dynamics in Complex Terrain: Implications for Fuel Moisture and Fire Regimes in Temperate Forests

NASA Astrophysics Data System (ADS)

Nyman, P.; Duff, T. J.; Sheridan, G. J.

2016-12-01

Moisture content in litter on the forest floor can control ignition and spread of forest fires. The micrometeorological factors driving variation in litter moisture at the landscape scale are poorly understood, particularly in areas with heterogeneous vegetation and complex terrain. In this research we seek to quantify how climate, vegetation and eco-hydrological feedbacks contribute to variation in net radiation and potential evaporation at the forest floor. Research sites were established at 12 locations in southeast Australia with variable precipitation, solar exposure, and drainage areas. Forests ranged from open woodland to tall temperate forests. We measured solar radiation, air temperature, relative humidity, litter moisture, soil moisture, and litter temperature. Forest structure was characterised using hemispherical photos and LIDAR. Using these data on microclimate and vegetation structure we parameterise a model of daily potential evaporation at the forest floor. Results show that variation in evaporation rates from litter is driven by net radiation and the role of vapour pressure deficit is almost negligible due to high aerodynamic resistance. In open woodlands the net radiation is directly related to short-wave radiation and evaporation remains high despite low temperatures. In the tall wet forests, commonly found along drainage lines and on slopes with polar-facing aspects, the long-wave radiation was just as important as the shortwave radiation. Air temperature is therefore important in determining the flammability of these more productive forests. By implication, in complex terrain with heterogeneous forests, the temperature in the wet parts of the landscape is important in controlling connectivity of fuels and large-scale fire activity.

Metaproteogenomics reveals the soil microbial communities active in nutrient cycling processes under different tree species

NASA Astrophysics Data System (ADS)

Keiblinger, Katharina Maria; Masse, Jacynthe; Zühlke, Daniela; Riedel, Katharina; Zechmeister-Boltenstern, Sophie; Prescott, Cindy E.; Grayston, Sue

2016-04-01

Tree species exert strong effects on microbial communities in litter and soil and may alter rates of soil processes fundamental to nutrient cycling and carbon fluxes (Prescott and Grayston 2013). However, the influence of tree species on decomposition processes are still contradictory and poorly understood. An understanding of the mechanisms underlying plant influences on soil processes is important for our ability to predict ecosystem response to altered global/environmental conditions. In order to link microbial community structure and function to forest-floor nutrient cycling processes, we sampled forest floors under western redcedar (Thuja plicata), Douglas-fir (Pseudotsuga menziesii) and Sitka spruce (Picea sitchensis) grown in nutrient-poor sites in common garden experiments on Vancouver island (Canada). We measured forest-floor total N, total C, initial NH4+ and NO3- concentrations, DOC, Cmic and Nmic. Gross rates of ammonification and NH4+ consumption were measured using the 15N pool-dilution method. Organic carbon quality was assessed through FTIR analyses. Microbial community structure was analysed by a metaproteogenomic approach using 16S and ITS amplification and sequencing with MiSeq platform. Proteins were extracted and peptides characterized via LC-MS/MS on a Velos Orbitrap to assess the active microbial community. Different microbial communities were active under the three tree species and variation in process rates were observed and will be discussed. This research provides new insights on microbial processes during organic matter decomposition. The metaproteogenomic approach enables us to investigate these changes with respect to possible effects on soil C-storage at even finer taxonomic resolution.

The Function of the Superficial Root Mat in the Biogeochemical Cycles of Nutrients in Congolese Eucalyptus Plantations

PubMed Central

LACLAU, JEAN‐PAUL; TOUTAIN, FRANÇOIS; M’BOU, ARMEL THONGO; ARNAUD, MICHEL; JOFFRE, RICHARD; RANGER, JACQUES

2004-01-01

• Background and Aims The importance of superficial root mats inside the forest floor for the nutrition of Amazonian rain forests has been extensively investigated. The present study was aimed at assessing the function of a root mat adherent to decomposing organic material observed in Eucalyptus plantations. • Methods The development of the root mat was studied through micromorphological observations of thin litter sections, and the influence of soil microtopography and soil water repellency on root mat biomass was assessed in situ on an area of 5 m2. In addition, input–output budgets of nutrients within the forest floor were established from measurements of litterfall, dissolved nutrients in gravitational solutions, and forest floor nutrient contents. • Key Findings The amounts of nutrients released during litter decay in this ecosystem during the period of study were, on average, 46, 3, 4, 19 and 17 kg ha–1 year–1 for N, P, K, Ca and Mg, respectively. The simultaneous measurements of the chemical composition of throughfall solutions and leachates beneath the forest floor showed a very quick uptake of nutrients by the root mat during the decomposition processes. Indeed, the solutions did not become noticeably enriched in nutrients during their passage through the holorganic layer, despite large amounts of elements being released during litter decay. The root mat biomass decreased significantly during the dry season, and a preferential development in microdepressions at the soil surface was observed. A strong water repellency observed in these depressions might enhance the ability of the roots to take up water and nutrients during the dry periods. • Conclusions The root mat was active throughout the year to catch the flux of nutrients from the biodegradation of the forest floor, preventing the transfer of dissolved nutrients toward deeper soil horizons. This mechanism is involved in the successful adaptation of this Eucalyptus hybrid in areas covered by ‘climacic’ savannas in Congo. PMID:14749252

Estimation of Moisture Content of Forest Canopy and Floor from SAR Data Part I: Volume Scattering Case

NASA Technical Reports Server (NTRS)

Moghaddam, M.; Saatchi, S.

1996-01-01

To understand and predict the functioning of forest biomes, their interaction with the atmosphere, and their growth rates, the knowledge of moisture content of their canopy and the floor soil is essential. The synthetic aperture radar on airborne and spaceborne platforms has proven to be a flexible tool for measuring electromagnetic back- scattering properties of vegetation related to their moisture content.

Whole-tree and forest floor removal from a loblolly pine plantation have no effect on forest floor CO2 efflux 10 years after harvest

Treesearch

John R. Butnor; Kurt H. Johnsen; Felipe G. Sanchez

2006-01-01

Intensive management of southern pine plantations has yielded multifold increases in productivity over the last half century. The process of harvesting merchantable material and preparing a site for planting can lead to a considerable loss of organic matter. Intensively managed stands may experience more frequent disturbance as rotations decrease in length, exposing...

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...

Ground-fire effects on the composition of dissolved and total organic matter in forest floor and soil solutions from Scots pine forests in Germany: new insights from solid state 13C NMR analysis

NASA Astrophysics Data System (ADS)

Näthe, Kerstin; Michalzik, Beate; Levia, Delphis; Steffens, Markus

2016-04-01

Fires represent an ecosystem disturbance and are recognized to seriously pertubate the nutrient budgets of forested ecosystems. While the effects of fires on chemical, biological, and physical soil properties have been intensively studied, especially in Mediterranean areas and North America, few investigations examined the effects of fire-induced alterations in the water-bound fluxes and the chemical composition of dissolved and particulate organic carbon and nitrogen (DOC, POC, DN, PN). The exclusion of the particulate organic matter fraction (0.45 μm < POM < 500 μm) potentially results in misleading inferences and budgeting gaps when studying the effects of fires on nutrient and energy fluxes. To our best knowledge, this is the first known study to present fire-induced changes on the composition of dissolved and total organic matter (DOM, TOM) in forest floor (FF) and soil solutions (A, B horizon) from Scots pine forests in Germany. In relation to control sites, we test the effects of low-severity fires on: (1) the composition of DOM and TOM in forest floor and soil solutions; and (2) the translocated amount of particulate in relation to DOC and DN into the subsoil. The project aims to uncover the mechanisms of water-bound organic matter transport along an ecosystem profile and its compositional changes following a fire disturbance. Forest floor and soil solutions were fortnightly sampled from March to December 2014 on fire-manipulated and control plots in a Scots pine forest in Central Germany. Shortly after the experimental duff fire in April 2014 pooled solutions samples were taken for solid-state 13C NMR spectroscopy to characterize DOM (filtered solution < 0.8μm pore size) and TOM in unfiltered solutions. Independent from fire manipulation, the composition of TOM was generally less aromatic (aromaticity index [%] according to Hatcher et al., 1981) with values between 18 (FF) - 25% (B horizon) than the DOM fraction with 23 (FF) - 27% (B horizon). For DOM in FF solution, fire manipulation caused an increase in aromaticity from 23 to 27% compared to the control, due to an increase of the aryl-C and a decrease of the O-alkyl-C and alkyl-C signal. Fire effects were leveled out in the mineral soil. For TOM, fire effects became notable only in the A horizon, exhibiting a decrease in aromaticity from 22 to 18% compared to the control, due to increased O-alkyl-C and diminished aryl-C proportions. Compared to the control, fire only caused minor DOC release rates (< 10%) in the FF and mineral soil, while DN in the FF was significantly mobilized (+ 40%) by fire exhibiting annual values of 33 at the control sites compared to 46 kg DN ha-1 at the fire treated sites. Compared to the control, fire events did not significantly enhance the proportion of POC and PN in the total C and N amounts exhibiting values between 10 and 20%. To fully understand the quality and amount of translocated organic C and N compounds within soils under both ambient as well as fire environments, dissolved and particulate size fractions need to be considered.

The response of ecosystem carbon pools to management approaches that increase the growth of loblolly pine (Pinus taeda L.)

NASA Astrophysics Data System (ADS)

Vogel, J. G.; Bacon, A. R.; Bracho, R. G.; Grunwald, S.; Gonzalez-Benecke, C. A.; Jokela, E. J.; Markewitz, D.; Cucinella, J.; Akers, K.; Ross, C. W.; Peter, G. F.; Fox, T. D.; Martin, T.; Kane, M.

2015-12-01

Extending from Virginia to east Texas in the southeastern United States, managed pine forests are an important component of the region's carbon cycle. One 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 forests. Experimental studies (108 total) that had historically been used to understand forest productivity and stand dynamics by university-forest industry cooperatives have now been measured for the carbon stored in the trees, coarse-wood, forest floor, understory and soils to 1-meter (0-10 cm, 10-20 cm, 20-50 cm, and 50-100 cm). The age of the studied forests ranged from 4-26 years at the time of sampling, with 26 years very near the period when these forests are commonly harvested. The study sites encapsulated a wide regional range in precipitation (1080 mm -1780 mm) and potential evapotranspiration (716 mm - 1200 mm). The most prevalent three soil orders measured were Ultisols (62%), Alfisols (19%), and Spodosols (10%) with Entisols, Inceptisols and 1 Histosol making up the remainder (9%). Across all study sites, 455 experimental plots were measured. The plots had as a treatment either fertilization, competition control, and stand density control (thinning), including every possible combination of treatments and also 'no treatment'. The most common treatment regime, at 36% of the total number of plots, was the combination of competition control, fertilization, and thinning. The distribution of treatments relative to soils and climate prevented a simple analysis of single treatment effects and instead necessitated an examination how the carbon accumulation rate in wood, which is commonly measured and modeled in these forests, corresponded to the response of other C pools (e.g. forest floor and soil).

Tree species and soil nutrient profiles in old-growth forests of the Oregon Coast Range

USGS Publications Warehouse

Cross, Alison; Perakis, Steven S.

2011-01-01

Old-growth forests of the Pacific Northwest provide a unique opportunity to examine tree species – soil relationships in ecosystems that have developed without significant human disturbance. We characterized foliage, forest floor, and mineral soil nutrients associated with four canopy tree species (Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), western redcedar (Thuja plicata Donn ex D. Don), and bigleaf maple (Acer macrophyllum Pursh)) in eight old-growth forests of the Oregon Coast Range. The greatest forest floor accumulations of C, N, P, Ca, Mg, and K occurred under Douglas-fir, primarily due to greater forest floor mass. In mineral soil, western hemlock exhibited significantly lower Ca concentration and sum of cations (Ca + Mg + K) than bigleaf maple, with intermediate values for Douglas-fir and western redcedar. Bigleaf maple explained most species-based differences in foliar nutrients, displaying high concentrations of N, P, Ca, Mg, and K. Foliar P and N:P variations largely reflected soil P variation across sites. The four tree species that we examined exhibited a number of individualistic effects on soil nutrient levels that contribute to biogeochemical heterogeneity in these ecosystems. Where fire suppression and long-term succession favor dominance by highly shade-tolerant western hemlock, our results suggest a potential for declines in both soil Ca availability and soil biogeochemical heterogeneity in old-growth forests.

Light accelerates plant responses to warming.

PubMed

De Frenne, Pieter; Rodríguez-Sánchez, Francisco; De Schrijver, An; Coomes, David A; Hermy, Martin; Vangansbeke, Pieter; Verheyen, Kris

2015-08-17

Competition for light has profound effects on plant performance in virtually all terrestrial ecosystems. Nowhere is this more evident than in forests, where trees create environmental heterogeneity that shapes the dynamics of forest-floor communities(1-3). Observational evidence suggests that biotic responses to both anthropogenic global warming and nitrogen pollution may be attenuated by the shading effects of trees and shrubs(4-9). Here we show experimentally that tree shade is slowing down changes in below-canopy communities due to warming. We manipulated levels of photosynthetically active radiation, temperature and nitrogen, alone and in combination, in a temperate forest understorey over a 3-year period, and monitored the composition of the understorey community. Light addition, but not nitrogen enrichment, accelerated directional plant community responses to warming, increasing the dominance of warmth-preferring taxa over cold-tolerant plants (a process described as thermophilization(6,10-12)). Tall, competitive plants took greatest advantage of the combination of elevated temperature and light. Warming of the forest floor did not result in strong community thermophilization unless light was also increased. Our findings suggest that the maintenance of locally closed canopy conditions could reduce, at least temporarily, warming-induced changes in forest floor plant communities.

Bryophyte species associations with coarse woody debris and stand ages in Oregon

USGS Publications Warehouse

Rambo, T.; Muir, Patricia S.

1998-01-01

We quantified the relationships of 93 forest floor bryophyte species, including epiphytes from incorporated litterfall, to substrate and stand age in Pseudotsuga menziesii-Tsuga heterophylla stands at two sites in western Oregon. We used the method of Dufrêne and Legendre that combines a species' relative abundance and relative frequency, to calculate that species' importance in relation to environmental variables. The resulting "indicator value" describes a species' reliability for indicating the given environmental parameter. Thirty-nine species were indicative of either humus, a decay class of coarse woody debris, or stand age. Bryophyte community composition changed along the continuum of coarse woody debris decomposition from recently fallen trees with intact bark to forest floor humus. Richness of forest floor bryophytes will be enhanced when a full range of coarse woody debris decay classes is present. A suite of bryophytes indicated old-growth forest. These were mainly either epiphytes associated with older conifers or liverworts associated with coarse woody debris. Hardwood-associated epiphytes mainly indicated young stands. Mature conifers, hardwoods, and coarse woody debris are biological legacies that can be protected when thinning managed stands to foster habitat complexity and biodiversity, consistent with an ecosystem approach to forest management.

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.

Severe soil frost reduced losses of carbon and nitrogen from the forest floor during simulated snowmelt: A laboratory experiment

Treesearch

Andrew B. Reinmann; Pamela H. Templer; John L. Campbell

2012-01-01

Considerable progress has been made in understanding the impacts of soil frost on carbon (C) and nitrogen (N) cycling, but the effects of soil frost on C and N fluxes during snowmelt remain poorly understood. We conducted a laboratory experiment to determine the effects of soil frost on C and N fluxes from forest floor soils during snowmelt. Soil cores were collected...

A Comparison of the Pitfall Trap, Winkler Extractor and Berlese Funnel for Sampling Ground-Dwelling Arthropods in Tropical Montane Cloud Forests

PubMed Central

Sabu, Thomas K.; Shiju, Raj T.; Vinod, KV.; Nithya, S.

2011-01-01

Little is known about the ground-dwelling arthropod diversity in tropical montane cloud forests (TMCF). Due to unique habitat conditions in TMCFs with continuously wet substrates and a waterlogged forest floor along with the innate biases of the pitfall trap, Berlese funnel and Winkler extractor are certain to make it difficult to choose the most appropriate method to sample the ground-dwelling arthropods in TMCFs. Among the three methods, the Winkler extractor was the most efficient method for quantitative data and pitfall trapping for qualitative data for most groups. Inclusion of floatation method as a complementary method along with the Winkler extractor would enable a comprehensive quantitative survey of ground-dwelling arthropods. Pitfall trapping is essential for both quantitative and qualitative sampling of Diplopoda, Opiliones, Orthoptera, and Diptera. The Winkler extractor was the best quantitative method for Psocoptera, Araneae, Isopoda, and Formicidae; and the Berlese funnel was best for Collembola and Chilopoda. For larval forms of different insect orders and the Acari, all the three methods were equally effective. PMID:21529148

Propagation of noise over and through a forest stand

Treesearch

Lee P. Herrington; C. Brock

1977-01-01

Measurements of the two-dimensional acoustic field in a forest resulting from a source located outside the forest indicated that the attenuation pattern near the ground is significantly different from the pattern higher up in the forest. The patterns of attenuation support the recent theory that the forest floor is the main absorber of acoustic energy in the forest....

Forest soil carbon is threatened by intensive biomass harvesting.

PubMed

Achat, David L; Fortin, Mathieu; Landmann, Guy; Ringeval, Bruno; Augusto, Laurent

2015-11-04

Forests play a key role in the carbon cycle as they store huge quantities of organic carbon, most of which is stored in soils, with a smaller part being held in vegetation. While the carbon storage capacity of forests is influenced by forestry, the long-term impacts of forest managers' decisions on soil organic carbon (SOC) remain unclear. Using a meta-analysis approach, we showed that conventional biomass harvests preserved the SOC of forests, unlike intensive harvests where logging residues were harvested to produce fuelwood. Conventional harvests caused a decrease in carbon storage in the forest floor, but when the whole soil profile was taken into account, we found that this loss in the forest floor was compensated by an accumulation of SOC in deeper soil layers. Conversely, we found that intensive harvests led to SOC losses in all layers of forest soils. We assessed the potential impact of intensive harvests on the carbon budget, focusing on managed European forests. Estimated carbon losses from forest soils suggested that intensive biomass harvests could constitute an important source of carbon transfer from forests to the atmosphere (142-497 Tg-C), partly neutralizing the role of a carbon sink played by forest soils.

Four-year measurement of methane flux over a temperate forest with a relaxed eddy accumulation method

NASA Astrophysics Data System (ADS)

Sakabe, A.; Kosugi, Y.; Ueyama, M.; Hamotani, K.; Takahashi, K.; Iwata, H.; Itoh, M.

2013-12-01

Forests are generally assumed to be an atmospheric methane (CH4) sink (Le Mer and Roger, 2001). However, under Asian monsoon climate, forests are subject to wide spatiotemporal range in soil water status, where forest soils often became water-saturated condition heterogeneously. In such warm and humid conditions, forests may act as a CH4 source and/or sink with considerable spatiotemporal variations. Micrometeorological methods such as eddy covariance (EC) method continuously measure spatially-representative flux at a canopy scale without artificial disturbance. In this study, we measured CH4 fluxes over a temperate forest during four-year period using a CH4 analyzer based on tunable diode laser spectroscopy detection with a relaxed eddy accumulation (REA) method (Hamotani et al., 1996, 2001). We revealed the amplitude and seasonal variations of canopy-scale CH4 fluxes. The REA method is the attractive alternative to the EC method to measure trace-gas flux because it allows the use of analyzers with an optimal integration time. We also conducted continuous chamber measurements on forest floor to reveal spatial variations in soil CH4 fluxes and its controlling processes. The observations were made in an evergreen coniferous forest in central Japan. The site has a warm temperate monsoon climate with wet summer. Some wetlands were located in riparian zones along streams within the flux footprint area. For the REA method, the sonic anemometer (SAT-550, Kaijo) was mounted on top of the 29-m-tall tower and air was sampled from just below the sonic anemometer to reservoirs according to the direction of vertical wind velocity (w). After accumulating air for 30 minutes, the air in the reservoirs was pulled into a CO2/H2O gas analyzer (LI-840, Li-Cor) and a CH4 analyzer (FMA-200, Los Gatos Research). Before entering the analyzers, the sampled air was dried using a gas dryer (PD-50 T-48; Perma Pure Inc.). The REA flux is obtained from the difference in the mean concentrations of the reservoirs. In the chamber method, automated dynamic-closed chambers were located at three points of water-unsaturated forest floor. Soil CO2 and CH4 fluxes were measured using the same analyzers with the REA method. CH4 fluxes showed seasonal variations at both canopy and plot scales. Based on the chamber measurements, water-unsaturated forest floor mostly consumed CH4 throughout a year. In contrast, canopy-scale CH4 fluxes by the REA method seasonally fluctuated between emission and absorption. The seasonal variation of canopy-scale CH4 fluxes varied at years to years. Every year, no notable emission nor absorption was observed during winter when daily average air temperature was less than about 10°C. In this forest, the canopy-scale CH4 fluxes could be determined by a balance between sources by methanogens and sinks by methanotrophs. Since these two processes were influenced by soil conditions (e.g., soil temperature and soil moisture), canopy-scale CH4 fluxes were influenced by CH4 fluxes from wetlands within the forest, because magnitude of wetland emission was a few order larger than those of absorption. We will discuss the factors of interannual variation of the canopy- and plot-scale CH4 fluxes in terms of precipitation patterns.

Seasonal change in precipitation, snowpack, snowmelt, soil water and streamwater chemistry, northern Michigan

USGS Publications Warehouse

Stottlemyer, R.; Toczydlowski, D.

1999-01-01

We have studied weekly precipitation, snowpack, snowmelt, soil water and streamwater chemistry throughout winter for over a decade in a small (176 ha) northern Michigan watershed with high snowfall and vegetated by 60 to 80 year-old northern hardwoods. In this paper, we examine physical, chemical, and biological processes responsible for observed seasonal change in streamwater chemistry based upon intensive study during winter 1996-1997. The objective was to define the contributions made to winter and spring streamwater chemical concentration and flux by processes as snowmelt, over-winter forest floor and surface soil mineralization, immobilization, and exchange, and subsurface flowpath. The forest floor and soil were unfrozen beneath the snowpack which permitted most snowmelt to enter. Over-winter soil mineralization and other biological processes maintain shallow subsurface ion and dissolved organic carbon (DOC) reservoirs. Small, but steady, snowmelt throughout winter removed readily mobilized soil NO3- which resulted in high over-winter streamwater concentrations but little flux. Winter soil water levels and flowpaths were generally deep which increased soil water and streamwater base cation (C(B)), HCO3-, and Si concentrations. Spring snowmelt increased soil water levels and removal of ions and DOC from the biologically active forest floor and shallow soils. The snowpack solute content was a minor component in determining streamwater ion concentration or flux during and following peak snowmelt. Exchangeable ions, weakly adsorbed anions, and DOC in the forest floor and surface soils dominated the chemical concentration and flux in soil water and streamwater. Following peak snowmelt, soil microbial immobilization and rapidly increased plant uptake of limiting nutrients removed nearly all available nitrogen from soil water and streamwater. During the growing season high evapotranspiration increased subsurface flowpath depth which in turn removed weathering products, especially C(B), HCO3-, and Si, from deeper soils. Soil water was a major component in the hydrologic and chemical budgets.We have studied weekly precipitation, snowpack, snowmelt, soil water and streamwater chemistry throughout winter for over a decade in a small (176 ha) northern Michigan watershed with high snowfall and vegetated by 60 to 80 year-old northern hardwoods. In this paper, we examine physical, chemical, and biological processes responsible for observed seasonal change in streamwater chemistry based upon intensive study during winter 1996-1997. The objective was to define the contributions made to winter and spring streamwater chemical concentration and flux by processes as snowmelt, over-winter forest floor and surface soil mineralization, immobilization, and exchange, and subsurface flowpath. The forest floor and soils were unfrozen beneath the snowpack which permitted most snowmelt to enter. Over-winter soil mineralization and other biological processes maintain shallow subsurface ion and dissolved organic carbon (DOC) reservoirs. Small, but steady, snowmelt throughout winter removed readily mobilized soil NO3- which resulted in high over-winter streamwater concentrations but little flux. Winter soil water levels and flowpaths were generally deep which increased soil water and streamwater base cation (CB), HCO3-, and Si concentrations. Spring snowmelt increased soil water levels and removal of ions and DOC from the biologically active forest floor and shallow soils. The snowpack solute content was a minor component in determining streamwater ion concentration or flux during and following peak snowmelt. Exchangeable ions, weakly adsorbed anions, and DOC in the forest floor and surface soils dominated the chemical concentration and flux in soil water and streamwater. Following peak snowmelt, soil microbial immobilization and rapidly increased plant uptake of limiting nutrients removed nearly all available nitrogen from soil water and streamwater. D

A Newly Identified Role of the Deciduous Forest Floor in the Timing of Green-Up

NASA Astrophysics Data System (ADS)

Lapenis, Andrei G.; Lawrence, Gregory B.; Buyantuev, Alexander; Jiang, Shiguo; Sullivan, Timothy J.; McDonnell, Todd C.; Bailey, Scott

2017-11-01

Plant phenology studies rarely consider controlling factors other than air temperature. We evaluate here the potential significance of physical and chemical properties of soil (edaphic factors) as additional important controls on phenology. More specifically, we investigate causal connections between satellite-observed green-up dates of small forest watersheds and soil properties in the Adirondack Mountains of New York, USA. Contrary to the findings of previous studies, where edaphic controls of spring phenology were found to be marginal, our analyses show that at least three factors manifest themselves as significant controls of seasonal patterns of variation in vegetated land surfaces observed from remote sensing: (1) thickness of the forest floor, (2) concentration of exchangeable soil potassium, and (3) soil acidity. For example, a thick forest floor appears to delay the onset of green-up. Watersheds with elevated concentrations of potassium are associated with early surface greening. We also found that trees growing in strongly acidified watersheds demonstrate delayed green-up dates. Overall, our work demonstrates that, at the scale of small forest watersheds, edaphic factors can explain a significant percentage of the observed spatial variation in land surface phenology that is comparable to the percentage that can be explained by climatic and landscape factors. We conclude that physical and chemical properties of forest soil play important roles in forest ecosystems as modulators of climatic drivers controlling the rate of spring soil warming and the transition of trees out of winter dormancy.

Topographic heterogeneity effect on the accumulation of Fukushima-derived radiocesium on forest floor driven by biologically mediated processes

NASA Astrophysics Data System (ADS)

Koarashi, Jun; Atarashi-Andoh, Mariko; Takeuchi, Erina; Nishimura, Syusaku

2014-10-01

The accident at the Fukushima Daiichi nuclear power plant caused serious radiocesium (137Cs) contamination of forest ecosystems located in mountainous and hilly regions with steep terrain. To understand topographic effects on the redistribution and accumulation of 137Cs on forest floor, we investigated the distribution of Fukushima-derived 137Cs in forest-floor litter layers on a steep hillslope in a Japanese deciduous forest in August 2013 (29 months after the accident). Both leaf-litter materials and litter-associated 137Cs were accumulated in large amounts at the bottom of the hillslope. At the bottom, a significant fraction (65%) of the 137Cs inventory was observed to be associated with newly shed and less degraded leaf-litter materials, with estimated mean ages of 0.5-1.5 years, added via litterfall after the accident. Newly emerged leaves were contaminated with Fukushima-derived 137Cs in May 2011 (two months after the accident) and 137Cs concentration in them decreased with time. However, the concentrations were still two orders of magnitude higher than the pre-accident level in 2013 and 2014. These observations are the first to show that 137Cs redistribution on a forested hillslope is strongly controlled by biologically mediated processes and continues to supply 137Cs to the bottom via litterfall at a reduced rate.

Parameterized isoprene and monoterpene emissions from the boreal forest floor: Implementation into a 1D chemistry-transport model and investigation of the influence on atmospheric chemistry

NASA Astrophysics Data System (ADS)

Mogensen, Ditte; Aaltonen, Hermanni; Aalto, Juho; Bäck, Jaana; Kieloaho, Antti-Jussi; Gierens, Rosa; Smolander, Sampo; Kulmala, Markku; Boy, Michael

2015-04-01

Volatile organic compounds (VOCs) are emitted from the biosphere and can work as precursor gases for aerosol particles that can affect the climate (e.g. Makkonen et al., ACP, 2012). VOC emissions from needles and leaves have gained the most attention, however other parts of the ecosystem also have the ability to emit a vast amount of VOCs. This, often neglected, source can be important e.g. at periods where leaves are absent. Both sources and drivers related to forest floor emission of VOCs are currently limited. It is thought that the sources are mainly due to degradation of organic matter (Isidorov and Jdanova, Chemosphere, 2002), living roots (Asensio et al., Soil Biol. Biochem., 2008) and ground vegetation. The drivers are biotic (e.g. microbes) and abiotic (e.g. temperature and moisture). However, the relative importance of the sources and the drivers individually are currently poorly understood. Further, the relative importance of these factors is highly dependent on the tree species occupying the area of interest. The emission of isoprene and monoterpenes where measured from the boreal forest floor at the SMEAR II station in Southern Finland (Hari and Kulmala, Boreal Env. Res., 2005) during the snow-free period in 2010-2012. We used a dynamic method with 3 automated chambers analyzed by Proton Transfer Reaction - Mass Spectrometer (Aaltonen et al., Plant Soil, 2013). Using this data, we have developed empirical parameterizations for the emission of isoprene and monoterpenes from the forest floor. These parameterizations depends on abiotic factors, however, since the parameterizations are based on field measurements, biotic features are captured. Further, we have used the 1D chemistry-transport model SOSAA (Boy et al., ACP, 2011) to test the seasonal relative importance of inclusion of these parameterizations of the forest floor compared to the canopy crown emissions, on the atmospheric reactivity throughout the canopy.

Does Long-Term Elevation of CO2 Concentration Increase Photosynthesis in Forest Floor Vegetation? (Indiana Strawberry in a Maryland Forest).

PubMed

Osborne, C. P.; Drake, B. G.; LaRoche, J.; Long, S. P.

1997-05-01

As the partial pressure of CO2 (pCO2) in the atmosphere rises, photorespiratory loss of carbon in C3 photosynthesis will diminish and the net efficiency of light-limited photosynthetic carbon uptake should rise. We tested this expectation for Indiana strawberry (Duchesnea indica) growing on a Maryland forest floor. Open-top chambers were used to elevate the pCO2 of a forest floor habitat to 67 Pa and were paired with control chambers providing an ambient pCO2 of 38 Pa. After 3.5 years, D. indica leaves grown and measured in the elevated pCO2 showed a significantly greater maximum quantum efficiency of net photosynthesis (by 22%) and a lower light compensation point (by 42%) than leaves grown and measured in the control chambers. The quantum efficiency to minimize photorespiration, measured in 1% O2, was the same for controls and plants grown at elevated pCO2. This showed that the maximum efficiency of light-energy transduction into assimilated carbon was not altered by acclimation and that the increase in light-limited photosynthesis at elevated pCO2 was simply a function of the decrease in photorespiration. Acclimation did decrease the ribulose-1,5-bisphosphate carboxylase/oxygenase and light-harvesting chlorophyll protein content of the leaf by more than 30%. These changes were associated with a decreased capacity for light-saturated, but not light-limited, photosynthesis. Even so, leaves of D. indica grown and measured at elevated pCO2 showed greater light-saturated photosynthetic rates than leaves grown and measured at the current atmospheric pCO2. In situ measurements under natural forest floor lighting showed large increases in leaf photosynthesis at elevated pCO2, relative to controls, in both summer and fall. The increase in efficiency of light-limited photosynthesis with elevated pCO2 allowed positive net photosynthetic carbon uptake on days and at locations on the forest floor that light fluxes were insufficient for positive net photosynthesis in the current atmospheric pCO2.

The role of forest floor and trees to the ecosystem scale methane budget of boreal forests

NASA Astrophysics Data System (ADS)

Pihlatie, Mari; Halmeenmäki, Elisa; Peltola, Olli; Haikarainen, Iikka; Heinonsalo, Jussi; Santalahti, Minna; Putkinen, Anuliina; Fritze, Hannu; Urban, Otmar; Machacova, Katerina

2016-04-01

Boreal forests are considered as a sink of atmospheric methane (CH4) due to the activity of CH4 oxidizing bacteria (methanotrophs) in the soil. This soil CH4 sink is especially strong for upland forest soils, whereas forests growing on organic soils may act as small sources due to the domination of CH4 production by methanogens in the anaerobic parts of the soil. The role of trees to the ecosystem-scale CH4 fluxes has until recently been neglected due to the perception that trees do not contribute to the CH4 exchange, and also due to difficulties in measuring the CH4 exchange from trees. Findings of aerobic CH4 formation in plants and emissions from tree-stems in temperate and tropical forests during the past decade demonstrate that our understanding of CH4 cycling in forest ecosystems is not complete. Especially the role of forest canopies still remain unresolved, and very little is known of CH4 fluxes from trees in boreal region. We measured the CH4 exchange of tree-stems and tree-canopies from pine (Pinus sylvestris), spruce (Picea abies) and birch (Betula pubescens, Betula pendula) trees growing in Southern Finland (SMEAR II station) on varying soil conditions, from upland mineral soils to paludified soil. We compared the CH4 fluxes from trees to forest-floor CH4 exchange, both measured by static chambers, and to CH4 fluxes measured above the forest canopy by a flux gradient technique. We link the CH4 fluxes from trees and forest floor to physiological activity of the trees, such as transpiration, sap-flow, CO2 net ecosystem exchange (NEE), soil properties such as temperature and moisture, and to the presence of CH4 producing methanogens and CH4 oxidizing methanotrophs in trees or soil. The above canopy CH4 flux measurements show that the whole forest ecosystem was a small source of CH4 over extended periods in the spring and summer 2012, 2014 and 2015. Throughout the 2013-2014 measurements, the forest floor was in total a net sink of CH4, with variation between high CH4 uptake in the dominating dry upland areas and high emissions from the few wet spots of the forest. All the studied tree species emitted small amounts of CH4 from the stems and shoots, with emission rates depending on the season, tree species and soil conditions. Especially, CH4 emissions from birch canopies were high and can therefore contribute significantly to the ecosystem-scale CH4 fluxes. Processes behind the canopy and stem CH4emission remain unresolved, however, ongoing analysis of the methanogens and methanotrophs within the plant-soil systems will reveal whether CH4 production or consumption is of microbial origin. Also, comparison of the CH4 fluxes from trees and forest floor to sap-flow, transpiration, and NEE as well as soil parameters will help to explain the seasonality and mechanisms involved in the CH4 emissions.

Forest floor and mineral soil respiration rates in a northern Minnesota red pine chronosequence

USGS Publications Warehouse

Powers, Matthew; Kolka, Randall; Bradford, John B.; Palik, Brian J.; Jurgensen, Martin

2018-01-01

We measured total soil CO2 efflux (RS) and efflux from the forest floor layers (RFF) in red pine (Pinus resinosaAit.) stands of different ages to examine relationships between stand age and belowground C cycling. Soil temperature and RS were often lower in a 31-year-old stand (Y31) than in 9-year-old (Y9), 61-year-old (Y61), or 123-year-old (Y123) stands. This pattern was most apparent during warm summer months, but there were no consistent differences in RFF among different-aged stands. RFF represented an average of 4–13% of total soil respiration, and forest floor removal increased moisture content in the mineral soil. We found no evidence of an age effect on the temperature sensitivity of RS, but respiration rates in Y61 and Y123 were less sensitive to low soil moisture than RS in Y9 and Y31. Our results suggest that soil respiration’s sensitivity to soil moisture may change more over the course of stand development than its sensitivity to soil temperature in red pine, and that management activities that alter landscape-scale age distributions in red pine forests could have significant impacts on rates of soil CO2 efflux from this forest type.

Use of monitoring and adaptive management to promote regeneration on the Allegheny National Forest

Treesearch

Lois DeMarco; Susan L. Stout

2001-01-01

Forest regeneration in the Allegheny Plateau Region of Pennsylvania is a continual challenge due to an overabundance of white-tailed deer (Odocoileus virginianus Zimmerman) and the resulting density of interfering plants on the forest floor. Guidelines developed to establish regeneration on the Allegheny National Forest rely on the silvical...

Stand and fuel treatments for restoring old-growth ponderosa pine forests in the interior west (Boise Basin Experimental Forest)

Treesearch

Russell T. Graham; Theresa B. Jain

2007-01-01

Fire exclusion, especially in the dry forests (i.e. those dominated or potentially dominated by ponderosa pine) has most often altered tree and shrub composition and structure and, though often overlooked in many locales, the forest floor from conditions that occurred historically (pre-1900).

Fine-Scale Vertical Stratification and Guild Composition of Saproxylic Beetles in Lowland and Montane Forests: Similar Patterns despite Low Faunal Overlap

PubMed Central

Weiss, Matthias; Procházka, Jiří; Schlaghamerský, Jiří; Cizek, Lukas

2016-01-01

Objective The finer scale patterns of arthropod vertical stratification in forests are rarely studied and poorly understood. Further, there are no studies investigating whether and how altitude affects arthropod vertical stratification in temperate forests. We therefore investigated the fine-scale vertical stratification of diversity and guild structure of saproxylic beetles in temperate lowland and montane forests and compared the resulting patterns between the two habitats. Methods The beetles were sampled with flight intercept traps arranged into vertical transects (sampling heights 0.4, 1.2, 7, 14, and 21 m). A triplet of such transects was installed in each of the five sites in the lowland and in the mountains; 75 traps were used in each forest type. Results 381 species were collected in the lowlands and 236 species in the mountains. Only 105 species (21%) were found at both habitats; in the montane forest as well as in the lowlands, the species richness peaked at 1.2 m, and the change in assemblage composition was most rapid near the ground. The assemblages clearly differed between the understorey (0.4 m, 1.2 m) and the canopy (7 m, 14 m, 21 m) and between the two sampling heights within the understorey, but less within the canopy. The stratification was better pronounced in the lowland, where canopy assemblages were richer than those near the forest floor (0.4 m). In the mountains the samples from 14 and 21 m were more species poor than those from the lower heights. The guild structure was similar in both habitats. Conclusions The main patterns of vertical stratification and guild composition were strikingly similar between the montane and the lowland forest despite the low overlap of their faunas. The assemblages of saproxylic beetles were most stratified near ground. The comparisons of species richness between canopy and understorey may thus give contrasting results depending on the exact sampling height in the understorey. PMID:26978783

The contributions of forest structure and substrate to bryophyte diversity and abundance in mature coniferous forests of the Pacific Northwest

Treesearch

Shelley A. Evans; Charles B. Halpern; Donald McKenzie

2012-01-01

Many aspects of forest structure are thought to contribute to the presence, abundance, and diversity of forest-floor bryophytes. To what extent easily measured characteristics of local environment (overstory structure or substrate availability) explain patterns of abundance and diversity remains unclear in most forest ecosystems. We explore these relationships in four...

Canopy soil bacterial communities altered by severing host tree limbs

PubMed Central

Dangerfield, Cody R.; Nadkarni, Nalini M.

2017-01-01

Trees of temperate rainforests host a large biomass of epiphytic plants, which are associated with soils formed in the forest canopy. Falling of epiphytic material results in the transfer of carbon and nutrients from the canopy to the forest floor. This study provides the first characterization of bacterial communities in canopy soils enabled by high-depth environmental sequencing of 16S rRNA genes. Canopy soil included many of the same major taxonomic groups of Bacteria that are also found in ground soil, but canopy bacterial communities were lower in diversity and contained different operational taxonomic units. A field experiment was conducted with epiphytic material from six Acer macrophyllum trees in Olympic National Park, Washington, USA to document changes in the bacterial communities of soils associated with epiphytic material that falls to the forest floor. Bacterial diversity and composition of canopy soil was highly similar, but not identical, to adjacent ground soil two years after transfer to the forest floor, indicating that canopy bacteria are almost, but not completely, replaced by ground soil bacteria. Furthermore, soil associated with epiphytic material on branches that were severed from the host tree and suspended in the canopy contained altered bacterial communities that were distinct from those in canopy material moved to the forest floor. Therefore, the unique nature of canopy soil bacteria is determined in part by the host tree and not only by the physical environmental conditions associated with the canopy. Connection to the living tree appears to be a key feature of the canopy habitat. These results represent an initial survey of bacterial diversity of the canopy and provide a foundation upon which future studies can more fully investigate the ecological and evolutionary dynamics of these communities. PMID:28894646

Canopy soil bacterial communities altered by severing host tree limbs.

PubMed

Dangerfield, Cody R; Nadkarni, Nalini M; Brazelton, William J

2017-01-01

Trees of temperate rainforests host a large biomass of epiphytic plants, which are associated with soils formed in the forest canopy. Falling of epiphytic material results in the transfer of carbon and nutrients from the canopy to the forest floor. This study provides the first characterization of bacterial communities in canopy soils enabled by high-depth environmental sequencing of 16S rRNA genes. Canopy soil included many of the same major taxonomic groups of Bacteria that are also found in ground soil, but canopy bacterial communities were lower in diversity and contained different operational taxonomic units. A field experiment was conducted with epiphytic material from six Acer macrophyllum trees in Olympic National Park, Washington, USA to document changes in the bacterial communities of soils associated with epiphytic material that falls to the forest floor. Bacterial diversity and composition of canopy soil was highly similar, but not identical, to adjacent ground soil two years after transfer to the forest floor, indicating that canopy bacteria are almost, but not completely, replaced by ground soil bacteria. Furthermore, soil associated with epiphytic material on branches that were severed from the host tree and suspended in the canopy contained altered bacterial communities that were distinct from those in canopy material moved to the forest floor. Therefore, the unique nature of canopy soil bacteria is determined in part by the host tree and not only by the physical environmental conditions associated with the canopy. Connection to the living tree appears to be a key feature of the canopy habitat. These results represent an initial survey of bacterial diversity of the canopy and provide a foundation upon which future studies can more fully investigate the ecological and evolutionary dynamics of these communities.

Measuring moisture dynamics to predict fire severity in longleaf pine forests.

Treesearch

Sue A. Ferguson; Julia E. Ruthford; Steven J. McKay; David Wright; Clint Wright; Roger Ottmar

2002-01-01

To understand the combustion limit of biomass fuels in a longleaf pine (Pinus palustris) forest, an experiment was conducted to monitor the moisture content of potentially flammable forest floor materials (litter and duff) at Eglin Air Force Base in the Florida Panhandle. While longleaf pine forests are fire dependent ecosystems, a long history of...

Interactions between white-tailed deer density and the composition of forest understories in the northern United States

Treesearch

Matthew B. Russell; Christopher W. Woodall; Kevin M. Potter; Brian F. Walters; Grant M. Domke; Christopher M. Oswalt

2017-01-01

Forest understories across the northern United States (US) are a complex of tree seedlings, endemic forbs, herbs, shrubs, and introduced plant species within a forest structure defined by tree and forest floor attributes. The substantial increase in white-tailed deer (Odocoileus virginianus Zimmerman) populations over the past decades has resulted...

How to estimate forest carbon for large areas from inventory data

Treesearch

James E. Smith; Linda S. Heath; Peter B. Woodbury

2004-01-01

Carbon sequestration through forest growth provides a low-cost approach for meeting state and national goals to reduce net accumulations of atmospheric carbon dioxide. Total forest ecosystem carbon stocks include "pools" in live trees, standing dead trees, understory vegetation, down dead wood, forest floor, and soil. Determining the level of carbon stocks in...

Rapid Shifts in Soil and Forest Floor Microbial Communities with Changes in Vegetation during Secondary Tropical Forest Succession

NASA Astrophysics Data System (ADS)

Smith, A.; Marin-Spiotta, E.; Balser, T. C.

2012-12-01

Soil microorganisms regulate fundamental biochemical processes in plant litter decomposition and soil organic matter (SOM) transformations. In order to predict how disturbance affects belowground carbon storage, it is important to understand how the forest floor and soil microbial community respond to changes in land cover, and the consequences on SOM formation and stabilization. We are measuring microbial functional diversity and activity across a long-term successional chronosequence of secondary forests regrowing on abandoned pastures in the wet subtropical forest life zone of Puerto Rico. Here we report intra- and interannual data on soil and litter microbial community composition (via phospholipid fatty acid analysis, PLFA) and microbial activity (via extracellular enzyme activity) from active pastures, secondary forests aged 20, 30, 40, 70, and 90-years, and primary forests. Microbial community composition and extracellular enzyme activity differed significantly by season in these wet subtropical ecosystems, even though differences in mean monthly precipitation between the middle of the dry season (January) and the wet season (July) is only 30mm. Despite seasonal differences, there was a persistent strong effect of land cover type and forest successional stage, or age, on overall microbial community PLFA structure. Using principal component analysis, we found differences in microbial community structure among active pastures, early, and late successional forests. The separation of soil microbes into early and late successional communities parallels the clustering of tree composition data. While the successional patterns held across seasons, the importance of different microbial groups driving these patterns differed seasonally. Biomarkers for gram-positive and actinobacteria (i15:0 and 16:0 10Me) were associated with early (20, 30 & 40 year old) secondary forests in the dry season. These younger forest communities were identified by the biomarker for anaerobic gram-negative bacteria (c19:0) in the wet season, which suggests the presence of anaerobic microsites in these very clayey Oxisols. Enzymatic activity did not differ with succession but was highest in the dry season. We expect this may be due to decreased turnover of enzymes with low soil moisture. Interannual sampling has revealed a very rapid microbial response to changes in aboveground cover. Within a year following woody biomass encroachment, we detected a shift in the soil microbial community from a pasture-associated community to an early secondary forest community in one of our replicate pasture sites. This very rapid response in the belowground microbial community structure to changes in vegetation has not been strongly documented in the literature. This data supports a direct link between aboveground and belowground biotic community structures and highlights the importance of long-term repeated sampling of microbial communities in dynamic ecosystems. Our findings have implications for predicting rapid ecological responses to land-cover change.

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,

Increased Calcium Availability Leads to Greater Forest Floor Accumulation in an Adirondack Forest

NASA Astrophysics Data System (ADS)

Melvin, A.; Goodale, C. L.

2010-12-01

Nutrient availability in Northeastern US forests has been dramatically altered by anthropogenic activities. Acid deposition has not only increased nitrogen (N) availability, but has also been linked to soil acidification and a loss of base cations, largely calcium (Ca). We are studying the long-term effects of a Ca addition on carbon (C) and N cycling in a forested catchment in the Adirondack Park, New York. In 1989, calcium carbonate (lime) was added to two subcatchments within the Woods Lake Watershed to ameliorate the effects of soil Ca depletion. Two additional subcatchments were left as controls. Eighteen years after the Ca application, both soil pH and exchangeable Ca concentrations remain elevated in the organic horizons and upper mineral soils of the treated subcatchments. The forest floor mass in this watershed is very large and measurements show that the organic layer in the limed subcatchments is significantly larger than in the controls (212 t/ha vs. 116 t/ha), resulting in greater C and N stocks in the Ca-amended soils. This finding suggests that Ca may stabilize soil organic matter (SOM), resulting in greater C storage under high soil Ca conditions. We are investigating potential drivers of this SOM accumulation in the limed subcatchments, including rates of leaf litter production and the decomposition rate of forest floor material. This work will provide important insights into how long-term changes in soil Ca availability influence SOM stabilization, retention and nutrient cycling.

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

Hesse, Cedar N.; Mueller, Rebecca C.; Vuyisich, Momchilo

Anthropogenic N deposition alters patterns of C and N cycling in temperate forests, where forest floor litter decomposition is a key process mediated by a diverse community of bacteria and fungi. To track forest floor decomposer activity we generated metatranscriptomes that simultaneously surveyed the actively expressed bacterial and eukaryote genes in the forest floor, to compare the impact of N deposition on the decomposers in two natural maple forests in Michigan, USA, where replicate field plots had been amended with N for 16 years. Site and N amendment responses were compared using about 74,000 carbohydrate active enzyme transcript sequences (CAZymes)more » in each metatranscriptome. Parallel ribosomal RNA (rRNA) surveys of bacterial and fungal biomass and taxonomic composition showed no significant differences in either biomass or OTU richness between the two sites or in response to N. Site and N amendment were not significant variables defining bacterial taxonomic composition, but they were significant for fungal community composition, explaining 17 and 14% of the variability, respectively. The relative abundance of expressed bacterial and fungal CAZymes changed significantly with N amendment in one of the forests, and N-response trends were also identified in the second forest. Although the two ambient forests were similar in community biomass, taxonomic structure and active CAZyme profile, the shifts in active CAZyme profiles in response to N-amendment differed between the sites. One site responded with an over-expression of bacterial CAZymes, and the other site responded with an over-expression of both fungal and different bacterial CAZymes. Both sites showed reduced representation of fungal lignocellulose degrading enzymes in N-amendment plots. The metatranscriptome approach provided a holistic assessment of eukaryote and bacterial gene expression and is applicable to other systems where eukaryotes and bacteria interact.« less

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.

Impact of Conifer Forest Litter on Microwave Emission at L-Band

NASA Technical Reports Server (NTRS)

Kurum, Mehmet; O'Neill, Peggy E.; Lang, Roger H.; Cosh, Michael H.; Joseph, Alicia T.; Jackson, Thomas J.

2011-01-01

This study reports on the utilization of microwave modeling, together with ground truth, and L-band (1.4-GHz) brightness temperatures to investigate the passive microwave characteristics of a conifer forest floor. The microwave data were acquired over a natural Virginia Pine forest in Maryland by a ground-based microwave active/passive instrument system in 2008/2009. Ground measurements of the tree biophysical parameters and forest floor characteristics were obtained during the field campaign. The test site consisted of medium-sized evergreen conifers with an average height of 12 m and average diameters at breast height of 12.6 cm. The site is a typical pine forest site in that there is a surface layer of loose debris/needles and an organic transition layer above the mineral soil. In an effort to characterize and model the impact of the surface litter layer, an experiment was conducted on a day with wet soil conditions, which involved removal of the surface litter layer from one half of the test site while keeping the other half undisturbed. The observations showed detectable decrease in emissivity for both polarizations after the surface litter layer was removed. A first-order radiative transfer model of the forest stands including the multilayer nature of the forest floor in conjunction with the ground truth data are used to compute forest emission. The model calculations reproduced the major features of the experimental data over the entire duration, which included the effects of surface litter and ground moisture content on overall emission. Both theory and experimental results confirm that the litter layer increases the observed canopy brightness temperature and obscure the soil emission.

Small mammals in young forests: implications for management for sustainability.

Treesearch

A.B. Carey; C.A. Harrington

2001-01-01

Small mammals have been proposed as indicators of sustainability in forests in the Pacific Northwest and elsewhere. Mammal community composition and species abundances purportedly result from interactions among species, forest-floor characteristics, large coarse woody debris, understory vegetation, and overstory composition. Coarse woody debris is thought to be...

Preliminary guidelines for prescribed burning under standing timber in western larch/douglas-fir forests

Treesearch

Rodney A. Norum

1977-01-01

Guidelines are offered for safe, effective fire treatments in western larch/Douglas-fir forests. Describes procedures for estimating and limiting the scorching of tree crows. Provides a method for predicting percentage of the forest floor that will be burned down to mineral soil.

Exploring the Relationship Between Reflectance Red Edge and Chlorophyll Content in Slash Pine

NASA Technical Reports Server (NTRS)

Curran, Paul J.; Dungan, Jennifer L.; Gholz, Henry L.

1990-01-01

Chlorophyll is a key indicator of the physiological status of a forest canopy. However, its distribution may vary greatly in time and space, so that the estimation of chlorophyll content of canopies or branches by extrapolation from leaf values obtained by destructive sampling is labor intensive and potentially inaccurate. Chlorophy11 content is related positively to the point of maximum slope in vegetation reflectance spectra which occurs at wavelengths between 690-740 nm and is known as the "red edge." The red edge of needles on individual slash pine (Piniis elliottii Engelm.) branches and in whole forest canopies was measured with a spectroradiometer. Branches were measured on the ground against a spectrally flat reflectance target and canopies were measured from observation towers against a spectrally variable understory and forest floor. There was a linear relationship between red edge and chlorophyll content of branches (R(exp 2) = 0.91). Measurements of the red edge and this relationship were used to estimate the chlorophyll content of other branches with an error that was lower than that associated with the colorimetric (laboratory) method. There was no relationship between the red edge and the chlorophyll content of whole canopies. This can be explained by the overriding influence of the understory and forest floor, an influence that was illustrated by spectral mixture modeling. The results suggest that the red edge could be used to estimate the chlorophyll content in branches but it is unlikely to be of value for the estimation of chlorophyll content in canopies unless the canopy cover is high.

Using FIA data to inform United States forest carbon national-level accounting needs: 1990-2010

Treesearch

Linda S. Heath

2013-01-01

Forests are partially made up of carbon. Live vegetation, dead wood, forest floor, and soil all contain carbon. Through the process of photosynthesis, trees reduce carbon dioxide to carbohydrates and store the carbon in wood. By removing carbon dioxide from the atmosphere, forests mitigate climate change that may be brought on by increased atmospheric CO2...

Forest water contamination

Treesearch

Roger M. Rowell

2006-01-01

Forests play a key role in cleaning water. Precipitation is “'filtered” through the tree canopy and filtered again throuph the organic matter on the forest floor. The water then seeps into the subsurface to replenish the ground water. Approximately 80% of the freshwater in the United States originates in the 650 million acres (265 million hectares) of forest that...

Beyond CO2 - Tackling the full greenhouse gas budget of a sub-alpine forest ecosystem

NASA Astrophysics Data System (ADS)

Burri, Susanne; Merbold, Lutz; Meier, Philip; Eugster, Werner; Hörtnagl, Lukas; Buchmann, Nina

2017-04-01

In order to tackle the full greenhouse gas (GHG) budgets of forest ecosystems, it is desirable but challenging to quantify the three major GHGs, i.e. CO2, CH4 and N2O simultaneously in-situ. At the long-term forest research site Davos (Candidate Class I Ecosystem Station within the Integrated Carbon Observation System - ICOS), we have recently installed a state-of-the-art measuring system simultaneously to observe the three GHGs on a high temporal resolution and both within and above the forest canopy. Thereby, we combine above-canopy eddy covariance flux measurements and forest floor chamber flux measurements (using five custom-made fully automated chambers). Both systems are connected to a quantum cascade laser absorption spectrometer (QCL, Aerodyne) and measurements are switched between three hours of above-canopy and one hour of forest floor GHG flux measurements. Using this approach, we will be able to study the full GHG budget as well as the dynamics of the individual fluxes on two vertical levels within the forest using a single instrument. The first results presented here will highlight the suitability of this promising tool for quantifying the full GHG budget of forest ecosystems.

Management impacts on forest floor and soil organic carbon in northern temperate forests of the US

Treesearch

Coeli M. Hoover

2011-01-01

The role of forests in the global carbon cycle has been the subject of a great deal of research recently, but the impact of management practices on forest soil dynamics at the stand level has received less attention. This study used six forest management experimental sites in five northern states of the US to investigate the effects of silvicultural treatments (light...

Increasing soil temperature in a northern hardwood forest: effects on elemental dynamics and primary productivity

Treesearch

Patrick J. McHale; Myron J. Mitchell; Dudley J. Raynal; Francis P. Bowles

1996-01-01

To investigate the effects of elevated soil temperatures on a forest ecosystem, heating cables were buried at a depth of 5 cm within the forest floor of a northern hardwood forest at the Huntington Wildlife Forest (Adirondack Mountains, New York). Temperature was elevated 2.5, 5.0 and 7.5?C above ambient, during May - September in both 1993 and 1994. Various aspects of...

Radionuclides deposition and fine sediment transport in a forested watershed, central Japan

NASA Astrophysics Data System (ADS)

Nam, S.; Gomi, T.; Kato, H.; Tesfaye, T.; Onda, Y.

2011-12-01

We investigated radionuclides deposition and fine sediment transport in a 13 ha headwater watershed, Tochigi prefecture, located in 98.94 km north of Tokyo. The study site was within Karasawa experimental forest, Tokyo University of Agriculture and Technology. We conducted fingerprinting approach, based on the activities of fallout radionuclides, including caesium-134 (Cs-134) caesium-137 (Cs-137) and excess lead-210 (Pb-210ex). For indentifying specific sources of fine sediment, we sampled tree, soil on forested floor, soil on logging road surface, stream bed and stream banks. We investigated the radionuclides (i.e., as Cs-134, Cs-137 and Pb-210ex) deposition on tree after accident of nuclear power plants on March 11, 2011. We sampled fruits, leaves, branches, stems, barks on Japanese cedar (Sugi) and Japanese cypress (Hinoki). To analyze the samples, gammaray spectrometry was performed at a laboratory at the University of Tsukuba (Tsukuba City, Japan) using n-type coaxial low-energy HPGe gamma detectors (EGC-200-R and EGC25-195-R of EURYSIS Co., Lingolsheim, France) coupled with a multichannel analyzer. We also collected soil samples under the forest canopy in various soil depths from 2, 5, 10, 20, 30 cm along transect of hillslopes. Samples at forest road were collected road segments crossing on the middle section of monitoring watersheds. Fine sediment transport in the streams were collected at the outlet of 13 ha watersheds using integrated suspended sediment samplers. This study indicates the some portion of radio nuclide potentially remained on the tree surface. Part of the deposited radionuclides attached to soil particles and transported to the streams. Most of the fine sediment can be transported on road surface and/or near stream side (riparian zones).

7. ARCHITECTURAL ELEVATIONS AND FLOOR PLANS OF OFFICE, SHEET 1 ...

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

7. ARCHITECTURAL ELEVATIONS AND FLOOR PLANS OF OFFICE, SHEET 1 OF 1, 8' X 10' NEGATIVE MADE FROM COPIES OF ORIGINAL PLANS, MAY 21, 1913; WALLOWA-WHITMAN NATIONAL FOREST SUPERVISOR'S OFFICE, BAKER CITY, OREGON - Wallowa Ranger Station, Office, 602 First Street, Wallowa, Wallowa County, OR

Nitrous oxide fluxes from forest floor, tree stems and canopies of boreal tree species during spring

NASA Astrophysics Data System (ADS)

Haikarainen, Iikka; Halmeenmäki, Elisa; Machacova, Katerina; Pihlatie, Mari

2017-04-01

Boreal forests are considered as small sources of atmospheric nitrous oxide (N2O) due to microbial N2O production in the soils. Recent evidence shows that trees may play an important role in N2O exchange of forest ecosystems by offering pathways for soil produced N2O to the atmosphere. To confirm magnitude, variability and the origin of the tree mediated N2O emissions more research is needed, especially in boreal forests which have been in a minority in such investigation. We measured forest floor, tree stem and shoot N2O exchange of three boreal tree species at the beginning of the growing season (13.4.-13.6.2015) at SMEAR II station in Hyytiälä, located in Southern Finland (61˚ 51´N, 24˚ 17´E, 181 a.s.l.). The fluxes were measured in silver birch (Betula pendula), downy birch (B. pubescens) and Norway spruce (Picea abies) on two sites with differing soil type and characteristics (paludified and mineral soil), vegetation cover and forest structure. The aim was to study the vertical profile of N2O fluxes at stem level and to observe temporal changes in N2O fluxes over the beginning of the growing season. The N2O exchange was determined using the static chamber technique and gas chromatographic analyses. Scaffold towers were used for measurements at multiple stem heights and at the canopy level. Overall, the N2O fluxes from the forest floor and trees at both sites were very small and close to the detection limit. The measured trees mainly emitted N2O from their stems and shoots, while the forest floor acted as a sink of N2O at the paludified site and as a small source of N2O at the mineral soil site. Stem emissions from all the trees at both sites were on average below 0.5 μg N2O m-2 of stem area h-1, and the shoot emissions varied between 0.2 and 0.5 ng N2O m-2 g-1 dry biomass. When the N2O fluxes were scaled up to the whole forest ecosystem, based on the tree biomass and stand density, the N2O emissions from birch and spruce trees at the paludified site were 1.4 and 2.2 mg N2O ha-1 h-1, respectively, while the forest floor was a sink of -6.1 mg N2O ha-1 h-1. At the mineral soil site the upscaled N2O emissions from birch trees and forest floor were 3.6 and 8.9 mg N2O ha-1 h-1, respectively, indicating that the emissions from trees significantly contribute to the N2O emissions from boreal forests. The results also indicate that tree canopies contributed up to 89% of the whole-tree N2O emissions. Our findings demonstrate that we urgently need more studies focusing on leaf-level N2O exchange in forest ecosystems. Acknowledgement This research was financially supported by the National Programme for Sustainability I (LO1415), Czech Science Foundation (17-18112Y), ENVIMET (CZ.1.07/2.3.00/20.0246) , Emil Aaltonen Foundation, Academy of Finland Research Fellow projects (292699, 263858, 288494), The Academy of Finland Centre of Excellence (projects 1118615, 272041), and ICOS-Finland (281255). We thank Hyytiälä SMEAR II station staff and Marek Jakubik for technical support.

Changes of polarimetric scattering characteristics of ALOS PALSAR caused by the 2011 Eruption of Shinmoe-dake Volcano

NASA Astrophysics Data System (ADS)

Ohkura, Hiroshi

Full polarimetric SAR images of ALOS PALSAR of Shinmoe-dake volcano in Japan were analyzed. The volcano erupted in January, 2011 and volcano ash deposited more than 10 cm in 12 km (2) and 1 m in 2 km (2) . Two images before and after the eruption were compared based on a point view of the four-component scattering model to detect changes of polarimetric scattering characteristics. The main detected changes are as follows. Total power of the four-component scattering model decreased on a farslope after the eruption. An incident angle on a farslope is larger than the angle on a foreslope. Decrease of surface roughness due to deposited volcanic ashes makes back-scattering smaller in the area of a larger incidence angle. However the rate of the double-bounce component got higher in a forest at the foot of a mountain slope and on a plain, where the ground surface is almost horizontal and the incident angle is relatively-large. Decrease of roughness of the forest floor increases forward scattering on the floor of the larger incident angle. This increases the double-bounced scattering due to bouncing back between the forest floor and trunks which stand "perpendicularly" on the almost horizontal forest floor. The rate of the surface scattering component got higher around an area where layover occurred. In the study area, most of layovers occurred at a ridge where an incidence angle was small. Decrease of surface roughness due to the ash deposit increases the surface scattering power in the area of the small incidence angle.

Formation and loss of humic substances during decomposition in a pine forest floor

USGS Publications Warehouse

Qualls, R.G.; Takiyama, A.; Wershaw, R. L.

2003-01-01

Since twice as much C is sequestered in soils as is contained in the atmosphere, the factors controlling the decomposition rate of soil C are important to the assessment of the effects of climatic change. The formation of chemically resistant humic substances might be an important process controlling recycling of CO2 to the atmosphere. Our objectives were to measure the rate of formation and loss of humic substances during 13 yr of litter decomposition. We placed nets on the floor of a white pine (Pinus strobus) forest to separate each annual layer of litter for 13 yr and measured humic substance concentration using NaOH extraction followed by chromatographic fractionation. The humic acid fraction increased from 2.1% of the C in litterfall to 15.7% after 1 yr. On a grams per square meter (g m-2) basis the humic substance fraction increased during the first year and then declined, with a half decay time (t1/2) of 5.1 yr, which was significantly slower than the bulk litter (t1/2 = 3.9 yr). The carboxylic C concentration estimated from 13C nuclear magnetic resonance (NMR) increased in the litter over time, though total mass of carboxylic acid C in the forest floor also declined over the 13-yr period (t1/2 = 4.6 yr). While humic substances in the forest floor decomposed at a somewhat slower rate than bulk litter during Years 1 to 13, they decomposed much faster than has been calculated from 14C dating of the refractory fraction of organic matter in the mineral soil.

Busy Nights: High Seed Dispersal by Crickets in a Neotropical Forest.

PubMed

Santana, Flávia Delgado; Baccaro, Fabricio Beggiato; Costa, Flávia Regina Capellotto

2016-11-01

Among invertebrates, ants are the most abundant and probably most important seed dispersers in both temperate and tropical environments. Crickets, also abundant in tropical forests, are omnivores and commonly attracted to fruits on the forest floor. However, their capability to remove seeds has been reported only once. We compared Marantaceae seed removal by crickets and ants to assess the role of crickets as secondary seed dispersers in Amazonia. Compared with ants, crickets dispersed an equivalent number of seeds and tended to disperse larger seeds farther. However, seed removal by crickets occurs mostly at night, suggesting that removal of arillate seeds by crickets on the tropical forest floor is probably being overlooked or wrongly attributed to other invertebrate groups. One potential consequence of seed dispersal by crickets may be a change in the local spatial distribution of arillate-seed species, due to lower aggregation around ant nests.

Understory vegetation response to mechanical mastication and other fuels treatments in a ponderosa pine forest

Treesearch

Jeffrey M. Kane; J. Morgan Varner; Eric E. Knapp

2010-01-01

Questions: What influence does mechanical mastication and other fuel treatments have on: (1) canopy and forest floor response variables that influence understory plant development; (2) initial understory vegetation cover, diversity, and composition; and (3) shrub and non-native species density in a secondgrowth ponderosa pine forest....

Control of Sediment Export From The Forest Road Prism

Treesearch

Johnny M. Grace

2002-01-01

The effectiveness of four road turn-out ditch treatments (vegetation, rip-rap, sediment fences, and settling basins) in reducing sediment export to the forest floor was evaluated. These four runoff control method are commonly prescribed to control forest road runoff and sediments. The study utilized runoff samplers, runoff diversion walls, sediment filter bags, and...

Soil properties and aspen development five years after compaction and forest floor removal

Treesearch

Douglas M. Stone; John D. Elioff

1998-01-01

Forest management activities that decrease soil porosity and remove organic matter have been associated with declines in site productivity. In the northern Lake States region, research is in progress in the aspen (Populus tremuloides Michx. and P. grandidentata Michx.) forest type to determine effects of soil compaction and organic...

Interception processes during snowstorms

Treesearch

David H. Miller

1964-01-01

Four processes are identified as determining the initial interception of falling snow by forest during storms: delivery of snow particles from the airstream to the forest; true throughfall of particles to the forest floor; impaction and adhesion of particles to foliage and branches; and cohesion of particles into masses of snow. Delivery and impaction processes seem...

Soil Organic Matter Responses to Chronic Nitrogen Additions in a Temperate Forest (Invited)

NASA Astrophysics Data System (ADS)

Frey, S. D.; Nadelhoffer, K.; Bowden, R.; Brzostek, E. R.; Caldwell, B. A.; Crow, S. E.; Finzi, A. C.; Goodale, C. L.; Grandy, S.; Lajtha, K.; Ollinger, S. V.; Plante, A. F.

2010-12-01

The Chronic Nitrogen Addition Experiment at Harvard Forest in central Massacusetts, USA was established in 1988 to investigate the effects of increasing anthropogenic atmospheric N deposition on forests in the eastern United States. Located in an old red pine plantation and a mixed hardwood forest, the treated plots have received 50 and 150 kg N/ha/yr, as ammonium sulfate, in six equal monthly applications during the growing season each year since the start of the experiment. Additionally, the control and low N treatments were given a single pulse label of 15N-nitrate or 15N-ammonium in 1991 and 1992. Regular measurements have been made over the past 20 years to assess woody biomass production and mortality, foliar chemistry, litter fall, and soil N dynamics. Less frequent measurements of soil C pools, soil respiration, fine root dynamics, and microbial biomass and community structure have been made. For the 20th anniversary, an intensive sampling campaign was carried out in fall 2008 with a focus on evaluating how the long-term N additions have impacted ecosystem C storage and N dynamics. Our primary objective was to assess the amount of C and N stored in wood, foliage, litter, roots, and soil (to a depth of ~50 cm). We also wanted to examine the fate of N by comparing patterns of 15N recovery to those observed previously. An additional objective was to further examine how chronic N additions impact microbial biomass, activity and community structure. Results indicate that chronic N additions over the past 20 years have increased forest floor mass and soil organic matter across the soil profile; decreased microbial biomass, especially the fungal component; and altered microbial community composition (i.e., significantly lower fungal:bacterial biomass ratios in the N amended plots). N15 tracer recoveries in soils and forest floors were much higher than in tree biomass, ranging from 49 to 101% of additions across forest types and N addition rates. Stoichiometric analyses of these recoveries suggest that N additions are contributing to soil C accumulation to a greater extent than to biomass accumulation in these forests.

Interactions between terrestrial mammals and the fruits of two neotropical rainforest tree species

NASA Astrophysics Data System (ADS)

Camargo-Sanabria, Angela A.; Mendoza, Eduardo

2016-05-01

Mammalian frugivory is a distinctive biotic interaction of tropical forests; however, most efforts in the Neotropics have focused on cases of animals foraging in the forest canopy, in particular primates and bats. In contrast much less is known about this interaction when it involves fruits deposited on the forest floor and terrestrial mammals. We conducted a camera-trapping survey to analyze the characteristics of the mammalian ensembles visiting fruits of Licania platypus and Pouteria sapota deposited on the forest floor in a well preserved tropical rainforest of Mexico. Both tree species produce large fruits but contrast in their population densities and fruit chemical composition. In particular, we expected that more species of terrestrial mammals would consume P. sapota fruits due to its higher pulp:seed ratio, lower availability and greater carbohydrate content. We monitored fruits at the base of 13 trees (P. sapota, n = 4 and L. platypus, n = 9) using camera-traps. We recorded 13 mammal species from which we had evidence of 8 consuming or removing fruits. These eight species accounted for 70% of the species of mammalian frugivores active in the forest floor of our study area. The ensemble of frugivores associated with L. platypus (6 spp.) was a subset of that associated with P. sapota (8 spp). Large body-sized species such as Tapirus bairdii, Pecari tajacu and Cuniculus paca were the mammals more frequently interacting with fruits of the focal species. Our results further our understanding of the characteristics of the interaction between terrestrial mammalian frugivores and large-sized fruits, helping to gain a more balanced view of its importance across different tropical forests and providing a baseline to compare against defaunated forests.

The efficacy of salvage logging in reducing subsequent fire severity in conifer-dominated forests of Minnesota, U.S.A.

PubMed

Fraver, Shawn; Jain, Theresa; Bradford, John B; D'Amato, Anthony W; Kastendick, Doug; Palik, Brian; Shinneman, Doug; Stanovick, John

2011-09-01

Although primarily used to mitigate economic losses following disturbance, salvage logging has also been justified on the basis of reducing fire risk and fire severity; however, its ability to achieve these secondary objectives remains unclear. The patchiness resulting from a sequence of recent disturbances-blowdown, salvage logging, and wildfire-provided an excellent opportunity to assess the impacts of blowdown and salvage logging on wildfire severity. We used two fire-severity assessments (tree-crown and forest-floor characteristics) to compare post-wildfire conditions among three treatment combinations (Blowdown-Salvage-Fire, Blowdown-Fire, and Fire only). Our results suggest that salvage logging reduced the intensity (heat released) of the subsequent fire. However, its effect on severity (impact to the system) differed between the tree crowns and forest floor: tree-crown indices suggest that salvage logging decreased fire severity (albeit with modest statistical support), while forest-floor indices suggest that salvage logging increased fire severity. We attribute the latter finding to the greater exposure of mineral soil caused by logging operations; once exposed, soils are more likely to register the damaging effects of fire, even if fire intensity is not extreme. These results highlight the important distinction between fire intensity and severity when formulating post-disturbance management prescriptions.

The efficacy of salvage logging in reducing subsequent fire severity in conifer-dominated forests of Minnesota, USA

USGS Publications Warehouse

Fraver, S.; Jain, T.; Bradford, J.B.; D'Amato, A.W.; Kastendick, D.; Palik, B.; Shinneman, D.; Stanovick, J.

2011-01-01

Although primarily used to mitigate economic losses following disturbance, salvage logging has also been justified on the basis of reducing fire risk and fire severity; however, its ability to achieve these secondary objectives remains unclear. The patchiness resulting from a sequence of recent disturbances-blowdown, salvage logging, and ildfire- provided an excellent opportunity to assess the impacts of blowdown and salvage logging on wildfire severity. We used two fire-severity assessments (tree-crown and forest-floor characteristics) to compare post-wildfire conditions among three treatment combinations (Blowdown-Salvage-Fire, Blowdown-Fire, and Fire only). Our results suggest that salvage logging reduced the intensity (heat released) of the subsequent fire. However, its effect on severity (impact to the system) differed between the tree crowns and forest floor: tree-crown indices suggest that salvage logging decreased fire severity (albeit with modest statistical support), while forest-floor indices suggest that salvage logging increased fire severity. We attribute the latter finding to the greater exposure of mineral soil caused by logging operations; once exposed, soils are more likely to register the damaging effects of fire, even if fire intensity is not extreme. These results highlight the important distinction between fire intensity and severity when formulating post-disturbance management prescriptions. ?? 2011 by the Ecological Society of America.

Vine maple (Acer circinatum) clone growth and reproduction in managed and unmanaged coastal Oregon douglas-fir forests

USGS Publications Warehouse

O'Dea, Mary E.; Zasada, John C.; Tappeiner, John C.

1995-01-01

Vine maple (Acer circinatum Pursh.) clone development, expansion, and regeneration by seedling establishment were studied in 5-240 yr old managed and unmanaged Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in coastal Oregon. Stem length, number of stems, and crown area were all significantly (P @10 m long and basal sprouts 1-2 m long; some stems had been pinned to the forest floor by fallen trees or branches and had layered. In stands >120 yr in age, clones were often quite complex, composed of several decumbent stems each of which connected the ramets of 1-10 new aerial stems. Vine maple clone expansion occurs by the layering of long aerial stems. Over 95% of the layered stems we observed had been pinned to the forest floor by fallen debris. Unsevered stems that we artificially pinned to the forest floor initiated roots within 1 yr. Thinning may favor clonal expansion because fallen slash from thinning often causes entire clones to layer, not just individual stems. Clonal vine maple seed production and seedling establishment occurred in all stages of stand development except dense, young stands following crown closure. There were more seedlings in thinned stands than in unthinned stands and in unburned clearcuts than in burned clearcuts.

Biomass removal and its effect on productivity of an artificially regenerated forest stand in the Missouri ozarks

Treesearch

Flex Jr. Ponder

2007-01-01

Intensive harvesting, which removes a greater proportion of the forest biomass than conventional harvesting and the associated nutrients, may cause a decline in forest productivity. Planted seedling response to three biomass removal levels (1. removal of boles only=OM1, 2. all surface organic matter removed, forest floor not removed=OM2, and 3. removal of all surface...

Measuring and modeling carbon stock change estimates for US forests and uncertainties from apparent inter-annual variability

Treesearch

James E. Smith; Linda S. Heath

2015-01-01

Our approach is based on a collection of models that convert or augment the USDA Forest Inventory and Analysis program survey data to estimate all forest carbon component stocks, including live and standing dead tree aboveground and belowground biomass, forest floor (litter), down deadwood, and soil organic carbon, for each inventory plot. The data, which include...

Height is more important than light in determining leaf morphology in a tropical forest

Treesearch

Molly A. Cavaleri; Steven F. Oberbauer; David B. Clark; Deborah A. Clark; Michael G. Ryan

2010-01-01

Both within and between species, leaf physiological parameters are strongly related to leaf dry mass per area (LMA, g/m2), which has been found to increase from forest floor to canopy top in every forest where it has been measured. Although vertical LMA gradients in forests have historically been attributed to a direct phenotypic response to light, an increasing number...

5. ARCHITECTURAL ELEVATIONS AND FLOOR PLANS OF GARAGE, SHEET 1 ...

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

5. ARCHITECTURAL ELEVATIONS AND FLOOR PLANS OF GARAGE, SHEET 1 OF 1, 8' X 10' NEGATIVE AND PRINT MADE FROM COPIES OF ORIGINAL PLANS, MAY 15, 1936, WALLOWA-WHITMAN NATIONAL FOREST SUPERVISOR'S, OFFICE, BAKER CITY, OREGON. - Wallowa Ranger Station, Garage, 602 First Street, Wallowa, Wallowa County, OR

5. ARCHITECTURAL ELEVATIONS AND FLOOR PLAN OF GAS HOUSE, SHEET ...

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

5. ARCHITECTURAL ELEVATIONS AND FLOOR PLAN OF GAS HOUSE, SHEET 1 OF 1, 8' X 10' NEGATIVE AND PRINT MADE FROM COPIES OF ORIGINAL PLANS, MAY 18, 1936, WALLOWA-WHITMAN NATIONAL FOREST SUPERVISOR'S, OFFICE, BAKER CITY, OREGON. - Wallowa Ranger Station, Gas House, 602 First Street, Wallowa, Wallowa County, OR

8. FLOOR PLANS OF FIRE EQUIPMENT BUILDING, SHEET 2 OF ...

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

8. FLOOR PLANS OF FIRE EQUIPMENT BUILDING, SHEET 2 OF 2, 8' X 10' NEGATIVE AND PRINT MADE FROM COPIES OF ORIGINAL PLANS, MAY 6, 1936, WALLOWA-WHITMAN NATIONAL FOREST SUPERVISOR'S OFFICE, BAKER CITY, OREGON. - Wallowa Ranger Station, Fire Equipment Building, 602 First Street, Wallowa, Wallowa County, OR

Height is more important than light in determining leaf morphology in a tropical forest.

PubMed

Cavaleri, Molly A; Oberbauer, Steven F; Clark, David B; Clark, Deborah A; Ryan, Michael G

2010-06-01

Both within and between species, leaf physiological parameters are strongly related to leaf dry mass per area (LMA, g/m2), which has been found to increase from forest floor to canopy top in every forest where it has been measured. Although vertical LMA gradients in forests have historically been attributed to a direct phenotypic response to light, an increasing number of recent studies have provided evidence that water limitation in the upper canopy can constrain foliar morphological adaptations to higher light levels. We measured height, light, and LMA of all species encountered along 45 vertical canopy transects across a Costa Rican tropical rain forest. LMA was correlated with light levels in the lower canopy until approximately 18 m sample height and 22% diffuse transmittance. Height showed a remarkably linear relationship with LMA throughout the entire vertical canopy profile for all species pooled and for each functional group individually (except epiphytes), possibly through the influence of gravity on leaf water potential and turgor pressure. Models of forest function may be greatly simplified by estimating LMA-correlated leaf physiological parameters solely from foliage height profiles, which in turn can be assessed with satellite- and aircraft-based remote sensing.

Variation in carbon storage and its distribution by stand age and forest type in boreal and temperate forests in northeastern China.

PubMed

Wei, Yawei; Li, Maihe; Chen, Hua; Lewis, Bernard J; Yu, Dapao; Zhou, Li; Zhou, Wangming; Fang, Xiangmin; Zhao, Wei; Dai, Limin

2013-01-01

The northeastern forest region of China is an important component of total temperate and boreal forests in the northern hemisphere. But how carbon (C) pool size and distribution varies among tree, understory, forest floor and soil components, and across stand ages remains unclear. To address this knowledge gap, we selected three major temperate and two major boreal forest types in northeastern (NE) China. Within both forest zones, we focused on four stand age classes (young, mid-aged, mature and over-mature). Results showed that total C storage was greater in temperate than in boreal forests, and greater in older than in younger stands. Tree biomass C was the main C component, and its contribution to the total forest C storage increased with increasing stand age. It ranged from 27.7% in young to 62.8% in over-mature stands in boreal forests and from 26.5% in young to 72.8% in over-mature stands in temperate forests. Results from both forest zones thus confirm the large biomass C storage capacity of old-growth forests. Tree biomass C was influenced by forest zone, stand age, and forest type. Soil C contribution to total forest C storage ranged from 62.5% in young to 30.1% in over-mature stands in boreal and from 70.1% in young to 26.0% in over-mature in temperate forests. Thus soil C storage is a major C pool in forests of NE China. On the other hand, understory and forest floor C jointly contained less than 13% and <5%, in boreal and temperate forests respectively, and thus play a minor role in total forest C storage in NE China.

Variation in Carbon Storage and Its Distribution by Stand Age and Forest Type in Boreal and Temperate Forests in Northeastern China

PubMed Central

Wei, Yawei; Li, Maihe; Chen, Hua; Lewis, Bernard J.; Yu, Dapao; Zhou, Li; Zhou, Wangming; Fang, Xiangmin; Zhao, Wei; Dai, Limin

2013-01-01

The northeastern forest region of China is an important component of total temperate and boreal forests in the northern hemisphere. But how carbon (C) pool size and distribution varies among tree, understory, forest floor and soil components, and across stand ages remains unclear. To address this knowledge gap, we selected three major temperate and two major boreal forest types in northeastern (NE) China. Within both forest zones, we focused on four stand age classes (young, mid-aged, mature and over-mature). Results showed that total C storage was greater in temperate than in boreal forests, and greater in older than in younger stands. Tree biomass C was the main C component, and its contribution to the total forest C storage increased with increasing stand age. It ranged from 27.7% in young to 62.8% in over-mature stands in boreal forests and from 26.5% in young to 72.8% in over-mature stands in temperate forests. Results from both forest zones thus confirm the large biomass C storage capacity of old-growth forests. Tree biomass C was influenced by forest zone, stand age, and forest type. Soil C contribution to total forest C storage ranged from 62.5% in young to 30.1% in over-mature stands in boreal and from 70.1% in young to 26.0% in over-mature in temperate forests. Thus soil C storage is a major C pool in forests of NE China. On the other hand, understory and forest floor C jointly contained less than 13% and <5%, in boreal and temperate forests respectively, and thus play a minor role in total forest C storage in NE China. PMID:23977252

Forest-floor disturbance reduces chipmunk (Tamias spp.) abundance two years after variable-retention harvest of Pacific Northwestern forests

Treesearch

Randall J. Wilk; Timothy B. Harrington; Robert A. Gitzen; Chris C. Maguire

2015-01-01

We evaluated the two-year effects of variable-retention harvest on chipmunk (Tamias spp.) abundance (N^) and habitat in mature coniferous forests in western Oregon and Washington because wildlife responses to density/pattern of retained trees remain largely unknown. In a randomized complete-block design, six...

Impacts of timber harvesting on soil organic matter, nitrogen, productivity, and health of inland northwest forests

Treesearch

M. F. Jurgensen; A. E. Harvey; R. T. Graham; D. S. Page-Dumroese; J. R. Tonn; M. J. Larsen; T. B. Jain

1997-01-01

Soil organic components are important factors in the health and productivity of Inland Northwest forests. Timber harvesting and extensive site preparation (piling, windrowing, or scalping) reduces the amount of surface organic material (woody residues and forest floor layers) over large areas. Some wildfires and severe prescribed burns can have similar consequences....

Nutritional hotspots and the secret life of forests

Treesearch

Jane Smith; Laurel Kluber; Noreen Parks

2014-01-01

The floor of a Douglas-fir forest may be rich in organic matter, but nutrients essential to plant growth are locked within the decomposing needles, leaves, and fallen wood. Before nitrogen, phosphorus, and other nutrients can be cycled back through the forest system, they need to be further broken down into forms accessible to plants. Understanding how nutrients become...

Infiltration, erosion, and vegetation recovery following road obliteration

Treesearch

R. B. Foltz; H. Rhee; K. A. Yanosek

2007-01-01

Forest roads are obliterated to lower the risks of surface erosion and mass failures. One purpose of the road obliteration is to return the compacted forest roads to productive pre-road conditions, i.e., a forest floor with high infiltration capacity, low interrill erodibility, and high vegetation ground cover. It is important to know how these characteristics recover...

Development and use of a commercial-scale biochar spreader

Treesearch

Deborah S. Page-Dumroese; Nathaniel M. Anderson; Keith N. Windell; Karl Englund; Kevin Jump

2016-01-01

Applying biochar to forest sites can be problematic and costly because of the need to keep the forest floor as undisturbed as possible during and after harvest operations. The Missoula Technology and Development Center of the U.S. Forest Service, working with Rocky Mountain Research Station scientists, developed and tested a high-capacity biochar spreader that can be...

Forest Floor Decomposition Following Hurricane Litter Inputs in Several Puerto Rican Forests

Treesearch

Rebecca Ostertag; Frederick N. Scatena; Whendee L. Silver

2003-01-01

Hurricanes affect ecosystem processes by altering resource availability and heterogeneity, but the spatial and temporal signatures of these events on biomass and nutrient cycling processes are not well understood. We examined mass and nutrient inputs of hurricane-derived litter in six tropical forests spanning three life zones in northeastern Puerto Rico after the...

Quantifying the effect of fuel reduction treatments on fire behavior in boreal forests

Treesearch

B.W. Butler; R.D. Ottmar; T.S. Rupp; R. Jandt; E. Miller; K. Howard; R. Schmoll; S. Theisen; R.E. Vihnanek; D. Jimenez

2013-01-01

Mechanical (e.g., shearblading) and manual (e.g., thinning) fuel treatments have become the preferred strategy of many fire managers and agencies for reducing fire hazard in boreal forests. This study attempts to characterize the effectiveness of four fuel treatments through direct measurement of fire intensity and forest floor consumption during a single prescribed...

A case study of nitrogen saturation in western U.S. forests

Treesearch

Mark E. Fenn; Mark A. Poth

2001-01-01

Virtually complete nitrification of the available ammonium in soil and nitrification activity in the forest floor are important factors predisposing forests in the San Bernardino Mountains of southern California to nitrogen (N) saturation. As a result, inorganic N in the soil solution is dominated by nitrate. High nitrification rates also generate elevated nitric oxide...

Changes in canopy processes following whole-forest canopy nitrogen fertilization of a mature spruce-hemlock forest

Treesearch

E. Gaige; D.B. Dail; D.Y. Hollinger; E.A. Davidson; I.J. Fernandez; H. Sievering; A. White; W. Halteman

2007-01-01

Most experimental additions of nitrogen to forest ecosystems apply the N to the forest floor, bypassing important processes taking place in the canopy, including canopy retention of N and/or conversion of N from one form to another. To quantify these processes, we carried out a large-scale experiment and determined the fate of nitrogen applied directly to a mature...

Variations in canopy and litter interception across a forest chronosequence in the southern Appalachian Mountains

Treesearch

Steven T. Brantley; Paul V. Bolstad; Stephanie H. Laseter; A. Christopher Oishi; Kimberly A. Novick; Chelcy F. Miniat

2016-01-01

Variations in evapotranspiration (ET) have been well documented across a variety of forest types and climates in recent decades; however, most of these data have focused on mature, secondgrowth stands. Here we present data on two important fluxes of water, canopy interception (Ic) and forest floor litter interception (Iff), across a chronosequence of forest age in the...

Pinus sylvestris as a missing source of nitrous oxide and methane in boreal forest.

PubMed

Machacova, Katerina; Bäck, Jaana; Vanhatalo, Anni; Halmeenmäki, Elisa; Kolari, Pasi; Mammarella, Ivan; Pumpanen, Jukka; Acosta, Manuel; Urban, Otmar; Pihlatie, Mari

2016-03-21

Boreal forests comprise 73% of the world's coniferous forests. Based on forest floor measurements, they have been considered a significant natural sink of methane (CH4) and a natural source of nitrous oxide (N2O), both of which are important greenhouse gases. However, the role of trees, especially conifers, in ecosystem N2O and CH4 exchange is only poorly understood. We show for the first time that mature Scots pine (Pinus sylvestris L.) trees consistently emit N2O and CH4 from both stems and shoots. The shoot fluxes of N2O and CH4 exceeded the stem flux rates by 16 and 41 times, respectively. Moreover, higher stem N2O and CH4 fluxes were observed from wet than from dry areas of the forest. The N2O release from boreal pine forests may thus be underestimated and the uptake of CH4 may be overestimated when ecosystem flux calculations are based solely on forest floor measurements. The contribution of pine trees to the N2O and CH4 exchange of the boreal pine forest seems to increase considerably under high soil water content, thus highlighting the urgent need to include tree-emissions in greenhouse gas emission inventories.

Roosevelt elk selection of temperate rain forest seral stages in western Washington

USGS Publications Warehouse

Schroer, Greg L.; Jenkins, Kurt J.; Moorhead, Bruce B.

1993-01-01

We studied habitat selection by Roosevelt elk (Cervus elaphus roosevelti) in a temperate rain forest in the lower Queets River Valley of the western Olympic Peninsula, Washington from June 1986-July 1987. Elk annual home ranges included predominantly unlogged forests protected within Olympic National Park and logged, regenerating forests adjacent to the park. Radio-collared elk selected valley floors during all seasons except winter, when elk frequently used an adjoining plateau 60 m above the floodplain. In winder, radio-collared elk selected 6-15 year-old clearcuts, which were available on the plateau. Elk selected mature deciduous forests of the valley floor during spring, summer, and autumn, and generally they selected old-age Sitka spruce forests during autumn and winter. Young clearcuts (1-5 years old) and even-aged, regenerating stands (16-150 years old) generally were avoided during all seasons. Management practices that retain preferred habitat of elk, such as deciduous forests, 6-15 yr-old coniferous stands, and old-age coniferous bottomland forests will benefit elk, particularly on elk ranges managed for short-rotation, even-aged stands. Silvicultural alternatives to typical even-aged stand management, such as uneven-aged management and commercial thinning, should also be considered for improving and maintaining interspersion of forage and cover.

Restoration of Black Oak (Quercus velutina) Sand Barrens via Three Different Habitat Management Approaches

NASA Astrophysics Data System (ADS)

Kriska, David John

Disturbance regimes, i.e. frequent fires, historically maintained oak barrens until European settlement patterns, and eventually, Smoky the Bear and the fire suppression campaign of the U.S. Forest Service snuffed out the periodic flames. In the absence of a disturbance regime, ground layer floral composition at many historical oak sand barrens will change predominantly because of a buildup of leaf litter and shading of the soils. Termed mesophication, this process of ecological succession will drive Black Oak Sand Barrens to an alternate steady state. A survey conducted on Singer Lake Bog in Green, Ohio, demonstrated that succession shifted the community to red maple-black cherry woodlands more typical of a dry southern forest. In an attempt to revive disturbance, three restoration techniques were applied at ten degraded northeast Ohio oak barrens to contrast their effectiveness in restoring black oak sand barren flora. The three restoration treatments were select canopy tree reduction favoring 5% to 30% tree canopy cover, forest floor leaf litter removal, and prescribed fire. Vegetation responses to manipulations were monitored prior to and following treatment applications, and were compared against both baseline data from before-treatment surveys and paired control sites adjacent treated areas. Imposing disturbance successfully increased species diversity and abundance above that found across Singer Lake Bog compared to sampling made prior to and adjacent to treated areas. Select canopy tree removal exhibited the largest floral responses from targeted barrens species, i.e. graminoids. A forest floor invertebrate family (Carabidea: Coleoptera) was measured for species richness and abundance pre and post treatment, where a noticeable shift occurred away from woodland obligate ground beetles toward open grassland species. Replicating oak barren structure, prior to replicating disturbance processes, is the first step in the ecological restoration of these systems.

Quality control troubleshooting tools for the mill floor

Treesearch

John Dramm

2000-01-01

Statistical Process Control (SPC) provides effective tools for improving process quality in the forest products industry resulting in reduced costs and improved productivity. Implementing SPC helps identify and locate problems that occur in wood products manufacturing. SPC tools achieve their real value when applied on the mill floor for monitoring and troubleshooting...

5. Photo copy of photograph, (original in Forest Service Office, ...

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

5. Photo copy of photograph, (original in Forest Service Office, Elkins, WV, photo #298181), D. A. Oliver, 1934. LOWER FLOOR, LOOKING WEST, SEED EXTRACTOR. - Parsons Nursery, Seed Extractor Building, South side of U.S. Route 219, Parsons, Tucker County, WV

The microbial community in decaying fallen logs varies with critical period in an alpine forest.

PubMed

Chang, Chenhui; Wu, Fuzhong; Yang, Wanqin; Xu, Zhenfeng; Cao, Rui; He, Wei; Tan, Bo; Justine, Meta Francis

2017-01-01

Little information has been available on the shifts in the microbial community in decaying fallen logs during critical periods in cold forests. Minjiang fir (Abies faxoniana) fallen logs in decay classes I-V were in situ incubated on the forest floor of an alpine forest in the eastern Tibet Plateau. The microbial community was investigated during the seasonal snow cover period (SP), snow thawing period (TP), early growing season (EG) and late growing season (LG) using Phosphorous Lipid Fatty Acid (PLFA) analysis. Total microbial biomass and microbial diversity in fallen logs were much more affected by critical period than decay class, whereas decay class had a stronger effect on microbial diversity than on microbial biomass. Abundant microbial biomass and microbial diversity in logs even without the cover of snow were observed in winter, which could not be linked to thermal insulation by snow cover. The freshly decayed logs functioned as an excellent buffer of environmental variation for microbial organisms during the sharp fluctuations in temperature in winter. We also found distinct decay patterns along with seasonality for heartwood, sapwood and bark, which requires further detailed research. Gram- bacteria mainly dominated the shifts in microbial community composition from SP to EG, while fungi and Gram+ bacteria mainly dominated it from SP to TP. Based on previous work and the present study, we conclude that fallen logs on the forest floor alter ecological processes by influencing microbial communities on woody debris and beneath the soil and litter. Our study also emphasizes the need to maintain a number of fallen logs, especially fresh ones, on the forest floor.

The microbial community in decaying fallen logs varies with critical period in an alpine forest

PubMed Central

Chang, Chenhui; Wu, Fuzhong; Xu, Zhenfeng; Cao, Rui; He, Wei; Tan, Bo; Justine, Meta Francis

2017-01-01

Little information has been available on the shifts in the microbial community in decaying fallen logs during critical periods in cold forests. Minjiang fir (Abies faxoniana) fallen logs in decay classes I-V were in situ incubated on the forest floor of an alpine forest in the eastern Tibet Plateau. The microbial community was investigated during the seasonal snow cover period (SP), snow thawing period (TP), early growing season (EG) and late growing season (LG) using Phosphorous Lipid Fatty Acid (PLFA) analysis. Total microbial biomass and microbial diversity in fallen logs were much more affected by critical period than decay class, whereas decay class had a stronger effect on microbial diversity than on microbial biomass. Abundant microbial biomass and microbial diversity in logs even without the cover of snow were observed in winter, which could not be linked to thermal insulation by snow cover. The freshly decayed logs functioned as an excellent buffer of environmental variation for microbial organisms during the sharp fluctuations in temperature in winter. We also found distinct decay patterns along with seasonality for heartwood, sapwood and bark, which requires further detailed research. Gram- bacteria mainly dominated the shifts in microbial community composition from SP to EG, while fungi and Gram+ bacteria mainly dominated it from SP to TP. Based on previous work and the present study, we conclude that fallen logs on the forest floor alter ecological processes by influencing microbial communities on woody debris and beneath the soil and litter. Our study also emphasizes the need to maintain a number of fallen logs, especially fresh ones, on the forest floor. PMID:28787465

Tree fern trunks facilitate seedling regeneration in a productive lowland temperate rain forest.

PubMed

Gaxiola, Aurora; Burrows, Larry E; Coomes, David A

2008-03-01

Seedling regeneration on forest floors is often impaired by competition with established plants. In some lowland temperate rain forests, tree fern trunks provide safe sites on which tree species establish, and grow large enough to take root in the ground and persist. Here we explore the competitive and facilitative effects of two tree fern species, Cyathea smithii and Dicksonia squarrosa, on the epiphytic regeneration of tree species in nutrient-rich alluvial forests in New Zealand. The difficulties that seedlings have in establishing on vertical tree fern trunks were indicated by the following observations. First, seedling abundance was greatest on the oldest sections of tree fern trunks, near the base, suggesting that trunks gradually recruited more and more seedlings over time, but many sections of trunk were devoid of seedlings, indicating the difficulty of establishment on a vertical surface. Second, most seedlings were from small-seeded species, presumably because smaller seeds can easily lodge on tree fern trunks. Deer browsing damage was observed on 73% of epiphytic seedlings growing within 2 m of the ground, whereas few seedlings above that height were browsed. This suggests that tree ferns provide refugia from introduced deer, and may slow the decline in population size of deer-preferred species. We reasoned that tree ferns would compete with epiphytic seedlings for light, because below the tree fern canopy photosynthetically active radiation (PAR) was about 1% of above-canopy PAR. Frond removal almost tripled %PAR on the forest floor, leading to a significant increase in the height growth rate (HGR) of seedlings planted on the forest floor, but having no effects on the HGRs of epiphytic seedlings. Our study shows evidence of direct facilitative interactions by tree ferns during seedling establishment in plant communities associated with nutrient-rich soils.

Projections of forest contributions to global carbon cycles

Treesearch

Michael E. Goerndt; Stephen R. Shifley; Patrick D. Miles; Dave Wear; Francisco X. Aguilar

2016-01-01

Forests cover 42 percent of the Northern United States, and collectively they store 13 billion tons of carbon in live trees (29 percent), roots (6 percent), forest floor (9 percent), dead trees (6 percent), and soils (50 percent). About half the biomass of a live tree (dry weight basis) is sequestered carbon (Woodall et al. 2011) - not the largest but the most dynamic...

Stereo photo series for quantifying natural fuels. Volume XII: Post-hurricane fuels in forests of the Southeast United States.

Treesearch

Robert E. Vihnanek; Cameron S. Balog; Clinton S. Wright; Roger D. Ottmar; Jeffrey W. Kelly

2009-01-01

Two series of single and stereo photographs display a range of natural conditions and fuel loadings in post-hurricane forests in the southeastern United States. Each group of photos includes inventory information summarizing vegetation composition, structure and loading, woody material loading and density by size class, forest floor loading, and various site...

Dynamics of calcium concentration in stemwood of red spruce and Siberian fir

Treesearch

Kevin T. Smith; Walter C. Shortle; Rakesh Minocha; Vladislav A. Alexeyev

1996-01-01

The atmospheric deposition of strong acid anions such as sulfate and nitrate shifts the ion exchange equilibrium in the rooting zone of sensitive forests. Red spruce and other northern coniferous forests are especially sensitive to deposition due to the shallow rooting of trees in a mor-type forest floor. Initially, the deposition of strong acid ions mobilizes...

Harvesting forest residues for bioenergy influences amphibian and herbaceous plant community assemblages in northern hardwood forests

Treesearch

Deahn M. Donner; Christine A. Ribic; Matthew St. Pierre; Daniel Eklund

2011-01-01

The most readily available source of woody biomass is through whole-tree harvesting that removes what has been traditionally left as slash [i.e., fine woody debris (FWD)]. While FWD has the potential to be used as energy feedstock, a critical element of managing for biodiversity is maintaining woody debris on the forest floor.

The Contribution of Microarthropods to Aboveground Food Webs: A Review and Model of Belowground Transfer in a Coniferous Forest

Treesearch

John M. Johnston

1999-01-01

Although below ground food webs have received much attention, studies concerning microarthropods in nondetrital food webs are scarce. because adult oribatid mites often number between 250.000-500,000/ m2 in coniferous forests, microarthropods are a potential food resource for macroarthropod and vertebrate predators of the forest floor. Although...

Land use change effects on forest carbon cycling throughout the southern United States

Treesearch

Peter B. Woodbury; Linda S. Heath; James E. Smith

2006-01-01

We modeled the effects of afforestation and deforestation on carbon cycling in forest floor and soil from 1900 to 2050 throughout 13 states in the southern United States. The model uses historical data on gross (two-way) transitions between forest, pasture, plowed agriculture, and urban lands along with equations describing changes in carbon over many decades for each...

Life on the edge: carbon fluxes from wetland to ocean along Alaska's coastal temperate rain forest

Treesearch

Rhonda Mazza; Richard Edwards; David D' Amore

2010-01-01

Acre for acre, streams of the coastal temperate rain forest along the Gulf of Alaska export 36 times as much dissolved organic carbon as the world average. Rain and snow are the great connectors, tightly linking aquatic and terrestrial systems of this region. The freshwater that flushes over and through the forest floor leaches carbon...

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...

Thinning effects on spotted owl prey and other forest-dwelling small mammals

Treesearch

Todd M. Willson; Eric D. Forsman

2013-01-01

Th inning has been promoted as a method for accelerating the development of late-seral habitat and improving the overall health and function of young forests in the Pacifi c Northwest. Population studies have shown early and positive responses to thinning by some small forest-floor mammals (primarily mice, terrestrial voles, and shrews). However, thinning reduces the...

4. Photo copy of photograph, (original in Forest Service Office, ...

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

4. Photo copy of photograph, (original in Forest Service Office, Elkins, WV, photo #298180, 'seed extracting equipment'), D. A. Oliver, 1934. LOWER FLOOR, LOOKING WEST, SEED EXTRACTOR. - Parsons Nursery, Seed Extractor Building, South side of U.S. Route 219, Parsons, Tucker County, WV

Vertical variability and effect of stability on turbulence characteristics down to the floor of a pine forest

NASA Astrophysics Data System (ADS)

Launiainen, Samuli; Vesala, Timo; Mölder, Meelis; Mammarella, Ivan; Smolander, Sampo; Rannik, Üllar; Kolari, Pasi; Hari, Pertti; Lindroth, Anders; Katul, Gabriel G.

2007-11-01

Among the fundamental problems in canopy turbulence, particularly near the forest floor, remain the local diabatic effects and linkages between turbulent length scales and the canopy morphology. To progress on these problems, mean and higher order turbulence statistics are collected in a uniform pine forest across a wide range of atmospheric stability conditions using five 3-D anemometers in the subcanopy. The main novelties from this experiment are: (1) the agreement between second-order closure model results and measurements suggest that diabatic states in the layer above the canopy explain much of the modulations of the key velocity statistics inside the canopy except in the immediate vicinity of the trunk space and for very stable conditions. (2) The dimensionless turbulent kinetic energy in the trunk space is large due to a large longitudinal velocity variance but it is inactive and contributes little to momentum fluxes. (3) Near the floor layer, a logarithmic mean velocity profile is formed and vertical eddies are strongly suppressed modifying all power spectra. (4) A spectral peak in the vertical velocity near the ground commensurate with the trunk diameter emerged at a moderate element Reynolds number consistent with Strouhal instabilities describing wake production.

Turn up the heat: thermal tolerances of lizards at La Selva, Costa Rica.

PubMed

Brusch, George A; Taylor, Emily N; Whitfield, Steven M

2016-02-01

Global temperature increases over the next century are predicted to contribute to the extinction of a number of taxa, including up to 40% of all lizard species. Lizards adapted to living in lowland tropical areas are especially vulnerable because of their dependence on specific microhabitats, low vagility, and a reduced capacity to physiologically adjust to environmental change. To assess the potential effects of climate change on lizards in the lowland tropics, we measured the critical thermal maximum (CTmax) of ten species from La Selva, Costa Rica. We also examined how well body size, microhabitat type, and species predicted the CTmax. We used current temperature data along with projected temperature increases for 2080 to predict which species may be at the greatest risk at La Selva. Of the ten species sampled, four are at serious risk of lowland extirpation and three others might also be at risk under the highest predicted temperature-increase models. Forest floor lizards at La Selva have already experienced significant population declines over the past 40 years, and we found that each of the forest floor species we studied is at serious risk of local extirpation. We also found that microhabitat type is the strongest predictor of CTmax, demonstrating the profound impact habitat specialization has on the thermal limits of tropical lizards.

Potential effects of forest management on surface albedo

NASA Astrophysics Data System (ADS)

Otto, J.; Bréon, F.-M.; Schelhaas, M.-J.; Pinty, B.; Luyssaert, S.

2012-04-01

Currently 70% of the world's forests are managed and this figure is likely to rise due to population growth and increasing demand for wood based products. Forest management has been put forward by the Kyoto-Protocol as one of the key instruments in mitigating climate change. For temperate and boreal forests, the effects of forest management on the stand-level carbon balance are reasonably well understood, but the biophysical effects, for example through changes in the albedo, remain elusive. Following a modeling approach, we aim to quantify the variability in albedo that can be attributed to forest management through changes in canopy structure and density. The modelling approach chains three separate models: (1) a forest gap model to describe stand dynamics, (2) a Monte-Carlo model to estimate the probability density function of the optical path length of photons through the canopy and (3) a physically-based canopy transfer model to estimate the interaction between photons and leaves. The forest gap model provides, on a monthly time step the position, height, diameter, crown size and leaf area index of individual trees. The Monte-Carlo model computes from this the probability density function of the distance a photon travels through crown volumes to determine the direct light reaching the forest floor. This information is needed by the canopy transfer model to calculate the effective leaf area index - a quantity that allows it to correctly represent a 3D process with a 1D model. Outgoing radiation is calculated as the result of multiple processes involving the scattering due to the canopy layer and the forest floor. Finally, surface albedo is computed as the ratio between incident solar radiation and calculated outgoing radiation. The study used two time series representing thinning from below of a beech and a Scots pine forest. The results show a strong temporal evolution in albedo during stand establishment followed by a relatively stable albedo once the canopy is closed. During this period, albedo is affected for a short time by forest operations. The modelling approach allowed us to estimate the importance of ground vegetation in the stand albedo. Given that ground vegetation depends on the light reaching the forest floor, ground vegetation could act as a natural buffer to dampen changes in albedo, allowing the stand to maintain optimal leaf temperature. Consequently, accounting for only the carbon balance component of forest management ignores albedo impacts and is thus likely to yield biased estimates of the climate benefits of forest ecosystems.

Ecophysiology of a Mangrove Forest in Jobos Bay, Puerto Rico

Treesearch

ARIEL E. LUGO; ERNESTO MEDINA; ELVIRA CUEVAs; CINTR& #211; GILBERTO N; EDDIE N. LABOY NIEVES; SCH& #196; YARA EFFER NOVELLI

2007-01-01

We studied gas exchange, leaf dimensions, litter production, leaf and litterfall chemistry, nutrient flux to the forest floor, retranslocation rates, and nutrient use efficiency of mangroves in Jobos Bay, Puerto Rico. The fringe forest had a salinity gradient from the ocean (35‰) to a salt flat (100‰) and a basin (about 80‰). Red (Rhizophora mangle), white (...

Effect of soil compaction and organic matter removal on two earthworm populations and some soil properties in a hardwood forest

Treesearch

D. Jordan; V. C. Hubbard; F., Jr. Ponder; E. C. Berry

1999-01-01

Earthworms can alter the physical, chemical, and biological properties of a forest ecosystem. Any physical manipulation to the soil ecosystem may, in turn, affect the activities and ecology of earthworms. The effects of organic matter removal (logs and forest floor) and soil compaction on earthworm activities were measured in a central hardwood region (oakhickory)...

Impacts of harvesting forest residues for bioenergy on herptofauna and herbaceous plant community assemblages in northern hardwood forests

Treesearch

Deahn M. Donner; Christine A. Ribic; Matthew St. Pierre; Dan Eklund

2011-01-01

The most readily available source of woody biomass is through whole-tree harvesting that removes what has been traditionally left as slash [i.e., fine woody debris (FWD)]. While FWD has the potential to be used as energy feedstock, a critical element of managing for biodiversity is maintaining woody debris on the forest floor.

Distribution of Slash and Litter After Wet- and Dry-Site Harvesting of Loblolly Pine Plantations

Treesearch

Mark H. Eisenbies; James A. Burger; Yi-Jun Xu; Steve Patterson

2002-01-01

Displacement of logging slash and forest floor litter in the process of harvesting can interfere with forest nutrient cycling and can modify soil climate in ways that could affect regeneration success and forest productivity. The objective of this study was to assess a visual method for estimating organic matter and slash biomass residues following a typical feller-...

When the douglas-firs were counted: The beginning of the Forest Survey

Treesearch

Ivan Doig

1976-01-01

The wonders which Phil Briegleb remembered from that stint of work - the dark green spill of forest from ridgeline to valley floor, the colonnade of giant boles crowding acre upon acre, the Depression-staving paycheck earned by sizing up this big timber - may have been grand, all right, but no more so than the language which spelled out the project. The Forest Survey...

National Wild Turkey Federation Programs

Treesearch

Rob Keck

2005-01-01

I recently read an article about several women who were preparing to sit 80 ft (25 m) above a forest floor in tree-sitting nets to protest a logging operation in Jefferson National Forest (Appalachia). Tree hugging is nothing new in this country. But did environmental activists know we have more forests now than we did in the 1920s? In 1920, we only had 735 million ac...

Precipitation nutrients in the open and under two forests in Minnesota

Treesearch

Elon S. Verry; D.R. Timmons

1977-01-01

Concentrations of N, P, K, Ca, Mg, and Na were measured in rain and snow in the open, and in throughfall and stemflow under black spruce and aspen forests in north-central Minnesota. Concentrations of total P in rain and black spruce throughfall were inversely related to storm size. Annual precipitation nutrient inputs to the forest floor were calculated for each site...

Ecosystem Function in Appalachian Headwater Streams during an Active Invasion by the Hemlock Woolly Adelgid

Treesearch

Robert M. Northington; Jackson R. Webster; Ernest F. Benfield; Beth M. Cheever; Barbara R. Niederlehner

2013-01-01

Forested ecosystems in the southeastern United States are currently undergoing an invasion by the hemlock woolly adelgid (HWA). Previous studies in this area have shown changes to forest structure, decreases in canopy cover, increases in organic matter, and changes to nutrient cycling on the forest floor and soil. Here, we were interested in how the effects of canopy...

Investigation of the spatial variability and possible origins of wind-induced air pressure fluctuations responsible for pressure pumping

NASA Astrophysics Data System (ADS)

Mohr, Manuel; Laemmel, Thomas; Maier, Martin; Zeeman, Matthias; Longdoz, Bernard; Schindler, Dirk

2017-04-01

The exchange of greenhouse gases between the soil and the atmosphere is highly relevant for the climate of the Earth. Recent research suggests that wind-induced air pressure fluctuations can alter the soil gas transport and therefore soil gas efflux significantly. Using a newly developed method, we measured soil gas transport in situ in a well aerated forest soil. Results from these measurements showed that the commonly used soil gas diffusion coefficient is enhanced up to 30% during periods of strong wind-induced air pressure fluctuations. The air pressure fluctuations above the forest floor are only induced at high above-canopy wind speeds (> 5 m s-1) and lie in the frequency range 0.01-0.1 Hz. Moreover, the amplitudes of air pressure fluctuations in this frequency range show a clear quadratic dependence on mean above-canopy wind speed. However, the origin of these wind-induced pressure fluctuations is still unclear. Airflow measurements and high-precision air pressure measurements were conducted at three different vegetation-covered sites (conifer forest, deciduous forest, grassland) to investigate the spatial variability of dominant air pressure fluctuations, their origin and vegetation-dependent characteristics. At the conifer forest site, a vertical profile of air pressure fluctuations was measured and an array consisting of five pressure sensors were installed at the forest floor. At the grassland site, the air pressure measurements were compared with wind observations made by ground-based LIDAR and spatial temperature observations from a fibre-optic sensing network (ScaleX Campaign 2016). Preliminary results show that at all sites the amplitudes of relevant air pressure fluctuations increase with increasing wind speed. Data from the array measurements reveal that there are no time lags between the air pressure signals of different heights, but a time lag existed between the air pressure signals of the sensors distributed laterally on the forest floor, suggesting a horizontal propagation of the air pressure waves.

Variation of biomass and carbon pools with forest type in temperate forests of Kashmir Himalaya, India.

PubMed

Dar, Javid Ahmad; Sundarapandian, Somaiah

2015-02-01

An accurate characterization of tree, understory, deadwood, floor litter, and soil organic carbon (SOC) pools in temperate forest ecosystems is important to estimate their contribution to global carbon (C) stocks. However, this information on temperate forests of the Himalayas is lacking and fragmented. In this study, we measured C stocks of tree (aboveground and belowground biomass), understory (shrubs and herbaceous), deadwood (standing and fallen trees and stumps), floor litter, and soil from 111 plots of 50 m × 50 m each, in seven forest types: Populus deltoides (PD), Juglans regia (JR), Cedrus deodara (CD), Pinus wallichiana (PW), mixed coniferous (MC), Abies pindrow (AP), and Betula utilis (BU) in temperate forests of Kashmir Himalaya, India. The main objective of the present study is to quantify the ecosystem C pool in these seven forest types. The results showed that the tree biomass ranged from 100.8 Mg ha(-1) in BU forest to 294.8 Mg ha(-1) for the AP forest. The understory biomass ranged from 0.16 Mg ha(-1) in PD forest to 2.36 Mg ha(-1) in PW forest. Deadwood biomass ranged from 1.5 Mg ha(-1) in PD forest to 14.9 Mg ha(-1) for the AP forest, whereas forest floor litter ranged from 2.5 Mg ha(-1) in BU and JR forests to 3.1 Mg ha(-1) in MC forest. The total ecosystem carbon stocks varied from 112.5 to 205.7 Mg C ha(-1) across all the forest types. The C stocks of tree, understory, deadwood, litter, and soil ranged from 45.4 to 135.6, 0.08 to 1.18, 0.7 to 6.8, 1.1 to 1.4, and 39.1-91.4 Mg ha(-1), respectively, which accounted for 61.3, 0.2, 1.4, 0.8, and 36.3 % of the total carbon stock. BU forest accounted 65 % from soil C and 35 % from biomass, whereas PD forest contributed only 26 % from soil C and 74 % from biomass. Of the total C stock in the 0-30-cm soil, about 55 % was stored in the upper 0-10 cm. Soil C stocks in BU forest were significantly higher than those in other forests. The variability of C pools of different ecosystem components is influenced by vegetation type, stand structure, management history, and altitude. Our results reveal that a higher percentage (63 %) of C is stored in biomass and less in soil in these temperate forests except at the higher elevation broad-leaved BU forest. Results from this study will enhance our ability to evaluate the role of these forests in regional and global C cycles and have great implications for planning strategies for conservation. The study provides important data for developing and validating C cycling models for temperate forests.

Influences of disturbance and vegetation on abundance of native and exotic detritivores in a southwestern riparian forest

Treesearch

D. Max Smith; Jeffrey F. Kelly; Deborah M. Finch

2006-01-01

Detritivores play important roles in energy and nutrient flow in riparian ecosystems. Endemic crickets (Gryllus alogus Rehn) and exotic isopods (Armadillidium vulagare Latreille and Porcellio laevi Latreille.) are abundant detritivores in riparian forest floors of central New Mexico. To determine how disturbance...

Legacy retention versus thinning: influences on small mammals.

Treesearch

S.M. Wilson; A.B. Carey

2000-01-01

Management strategies for promoting late-seral attributes in second-growth forest need evaluation for their efficacy in maintaining biodiversity, including complete forest-floor, small-mammal communities. Two common strategies in the Pacific Northwest are (1) management with thinnings to promote large trees with developed understories and (2) retention of legacies,...

Transverse vibration technique to identify deteriorated wood floor systems

Treesearch

R.J. Ross; X. Wang; M.O. Hunt; L.A. Soltis

2002-01-01

The Forest Products Laboratory, USDA Forest Service, has been developing nondestructive evaluation (NDE) techniques to identify degradation of wood in structures and the performance characteristics that remain in the structure. This work has focused on using dynamic testing techniques, particularly stress wave and ultrasonic transmission NDE techniques for both...

Headwater riparian forest-floor invertebrate communities associated with alternative forest management practices.

Treesearch

J.J. Rykken; A.R. Moldenke; D.H. Olson

2007-01-01

Invertebrate communities were characterized in unmanaged headwaters, and the effects of clearcutting without buffers and with buffers of approximately 30 m was examined. A near-stream community was distinct and largely retained by the buffers. Elevation, location, and microclimate were predictors of community structure.

SOIL TYPE AND FOREST VEGETATION INFLUENCES ON FOREST FLOOR NITROGEN DYNAMICS AT THE BEAR BROOK WATERSHED IN MAINE. (R825762)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Upland Trees Contribute to Exchange of Nitrous Oxide (N2O) in Forest Ecosystems

NASA Astrophysics Data System (ADS)

Tian, H.; Thompson, R.; Canadell, J.; Winiwarter, W.; Machacova, K.; Maier, M.; Halmeenmäki, E.; Svobodova, K.; Lang, F.; Pihlatie, M.; Urban, O.

2017-12-01

The increase in atmospheric nitrous oxide (N2O) concentration contributes to the acceleration of the greenhouse effect. However, the role of trees in the N2O exchange of forest ecosystems is still an open question. While the soils of temperate and boreal forests were shown to be a natural source of N2O, trees have been so far overlooked in the forest N2O inventories. We determined N2O fluxes in common tree species of boreal and temperate forests: Scots pine (Pinus sylvestris), Norway spruce (Picea abies), downy and silver birch (Betula pubescens, B. pendula), and European beech (Fagus sylvatica). We investigated (1) whether these tree species exchange N2O with the atmosphere under natural field conditions, (2) how the tree N2O fluxes contribute to the forest N2O balance, and (3) whether these fluxes show seasonal dynamics. The studies were performed in a boreal forest (SMEAR II station, Finland; June 2014 - May 2015) and two temperate mountain forests (White Carpathians, Czech Republic; Black Forest, Germany; June and July 2015). Fluxes of N2O in mature tree stems and forest floor were measured using static chamber systems followed by chromatographic and photo-acoustic analyses of N2O concentration changes. Pine, spruce and birch trees were identified as net annual N2O sources. Spruce was found the strongest emitter (0.27 mg ha-1 h-1) amounting thus up to 2.5% of forest floor N2O emissions. All tree species showed a substantial seasonality in stem N2O flux that was related to their physiological activity and climatic variables. In contrast, stems of beech trees growing at soils consuming N2O may act as a substantial sink of N2O from the atmosphere. Consistent N2O consumption by tree stems ranging between -12.1 and -35.2 mg ha-1 h-1 and contributing by up to 3.4% to the forest floor N2O uptake is a novel finding in contrast to current studies presenting trees as N2O emitters. To understand these fluxes, N2O exchange of photoautotrophic organisms associated with beech bark (lichens, mosses and algae) was quantified. All the organisms were net N2O sinks at full rehydration with consumption rates comparable to stem consumption rates. All tree species studied contribute to N2O exchange in forest ecosystems and these fluxes have to be included in the forest N2O emission inventories.

Oribatid mites and nutrient cycling. [Nutrient release by decomposition of leaf litter

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

Crossley, D.A. Jr.

1976-08-01

Communities of oribatid mites (Cryptostigmata) in leaf litter and forest soils consist of an impressive number of individuals. Total populations of the order of 10/sup 5/ oribatids per square meter are commonly reported from forest floors. Because of their numbers, oribatids have been believed to be important contributors to the breakdown of organic detritus. Results are reported from studies of mineral or nutrient element cycling in forest floor ecosystems using radioisotopes as tracers. The phenomenon of cycling allows for the study of feedback loops among ecosystem processes, whereas energy flow is unidirectional. Evaluation of feedback loops can be a meansmore » of quantifying indirect effects of consumers. The availability of radioactive isotopes or radioactive analogs of mineral elements allows for the direct measurement of transfer rates. In decomposition studies applications of radioactive tracers have helped to identify pathways of transfer from microflora to oribatids.« less

Soil compaction and organic matter affect conifer seedling nonmycorrhizal and ectomycorrhizal root tip abundance and diversity. Forest Service research paper

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

Amaranthus, M.P.; Page-Dumroese, D.; Harvey, A.

1996-05-01

Three levels of organic matter removal (bole only; bole and crowns; and bole, crowns, and forest floor) and three levels of mechanical soil compaction (no compaction, moderate compaction, and severe soil compaction) were studied as they influence Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) and western white pine (Pinus monticola Dougl. ex D. Don) seedlings following outplanting. Moderate and severe soil compaction significantly reduced nonmycorrhizal root tip abundance on both Douglas-fir and western white pine seedlings (p less than or equal to 0.05). Ectomycorrhizal root tip abundance was significantly reduced on Douglas-fir seedlings in severely compacted areas with bole andmore » crowns and bole, crowns, and forest floor removed. Ectomycorrhizal diversity also was significantly reduced on Douglas-fir seedlings in all severely compacted areas.« less

Uncertainties in detecting decadal change in extractable soil elements in Northern Forests

NASA Astrophysics Data System (ADS)

Bartlett, O.; Bailey, S. W.; Ducey, M. J.

2016-12-01

Northern Forest ecosystems have been or are being impacted by land use change, forest harvesting, acid deposition, atmospheric CO2 enrichment, and climate change. Each of these has the potential to modify soil forming processes, and the resulting chemical stocks. Horizontal and vertical variations in concentrations complicate determination of temporal change. This study evaluates sample design, sample size, and differences among observers as sources of uncertainty when quantifying soil temporal change over regional scales. Forty permanent, northern hardwood, monitoring plots were established on the White Mountain National Forest in central New Hampshire and western Maine. Soil pits were characterized and sampled by genetic horizon at plot center in 2001 and resampled again in 2014 two-meters on contour from the original sampling location. Each soil horizon was characterized by depth, color, texture, structure, consistency, boundaries, coarse fragments, and roots from the forest floor to the upper C horizon, the relatively unaltered glacial till parent material. Laboratory analyses included pH in 0.01 M CaCl2 solution and extractable Ca, Mg, Na, K, Al, Mn, and P in 1 M NH4OAc solution buffered at pH 4.8. Significant elemental differences were identified by genetic horizon from paired t-tests (p ≤ 0.05) indicate temporal change across the study region. Power analysis, 0.9 power (α = 0.05), revealed sampling size was appropriate within this region to detect concentration change by genetic horizon using a stratified sample design based on topographic metrics. There were no significant differences between observers' descriptions of physical properties. As physical properties would not be expected to change over a decade, this suggests spatial variation in physical properties between the pairs of sampling pits did not detract from our ability to detect temporal change. These results suggest that resampling efforts within a site, repeated across a region, to quantify elemental change by carefully described genetic horizons is an appropriate method of detecting soil temporal change in this region. Sample size and design considerations from this project will have direct implications for future monitoring programs to characterize change in soil chemistry.

Chloride cycling in two forested lake watersheds in the west-central Adirondack Mountains, New York, U.S.A.

USGS Publications Warehouse

Peters, N.E.

1991-01-01

The chemistry of precipitation, throughfall, soil water, ground water, and surface water was evaluated in two forested lake-watersheds over a 4-yr period to assess factors controlling C1- cycling. Results indicate that C1- cycling in these watersheds is more complex than the generally held view of the rapid transport of atmospherically derived C1- through the ecosystem. The annual throughfall Cl- flux for individual species in the northern hardwood forest was 2 to 5 times that of precipitation (56 eq ha-1), whereas the Na+ throughfall flux, in general, was similar to the precipitation flux. Concentrations of soil-water Cl- sampled from ceramic tension lysimeters at 20 cm below land surface generally exceeded the Na+ concentrations and averaged 31 ??eq L-1, the highest of any waters sampled in the watersheds, except throughfall under red spruce which averaged 34 ??eq L-1. Chloride was concentrated prior to storms and mobilized rapidly during storms as suggested by increases in streamwater Cl- concentrations with increasing flow. Major sources of Cl- in both watersheds are the forest floor and hornblende weathering in the soils and till. In the Panther Lake watershed, which contains mainly thick deposits of till( > 3 m), hornblende weathering results in a net Cl- flux 3 times greater than that in the Woods Lake watershed, which contains mainly thin deposits of till. The estimated accumulation rate of Cl- in the biomass of the two watersheds was comparable to the precipitation Cl- flux.The chemistry of precipitation, throughfall, soil water, ground water, and surface water was evaluated in two forested lake-watersheds over a 4-yr period to assess factors controlling Cl- cycling. Results indicate that Cl- cycling in these watersheds is more complex than the generally held view of the rapid transport of atmospherically derived Cl- through the excosystem. The annual throughfall Cl- flux for individual species in the northern hardwood forest was 2 to 5 times that of precipitation (56 eq ha-1), whereas the Na+ throughfall flux, in general, was similar to the precipitation flux. Concentrations of soil-water Cl- sampled from ceramic tension lysimeters at 20 cm below land surface generally exceeded the Na+ concentrations and averaged 31 ??eq L-1, the highest of any waters sampled in the watersheds, except throughfall under red spruce which averaged 34 ??eq L-1. Chloride was concentrated prior to storms and mobilized rapidly during storms as suggested by increases in streamwater Cl- concentrations with increasing flow. Major sources of Cl- in both watersheds are the forest floor and hornblende weathering in the soils and till. In the Panther Lake watershed, which contains mainly thick deposits of till (> 3 m), hornblende weathering results in a net Cl- flux 3 times greater than that in the Woods Lake watershed, which contains mainly thin deposits of till. The estimated accumulation rate of Cl- in the biomass of the two watersheds was comparable to the precipitation Cl- flux.

Calcium, potassium, and sodium content of forest floor arthropods

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

Reichle, D.E.; Shanks, M.H.; Crossley, D.A. Jr.

1969-01-01

Whole-body nutrient composition of calcium, potassium, and sodium is documented for 37 species of forest floor arthropods. Sodium concentrations averaging 4.6 mg Na/g ash-free dry weight, and potassium concentrations averaging 6.2 mg K/g ash-free dry weight were relatively consistent within and among major taxonomic categories. Calcium content varied from 0.3 to 509.8 mg Ca/g ash-free dry weight, with highest values associated with Diplopoda and related species possessing highly calcified exoskeletons. Within-species variation in chemical composition often exceeded seasonal fluctuations, although several species exhibited significant temporal changes in whole-body nutrient composition of calcium, potassium, and sodium. 9 references, 3 tables.

Grass invasion of a hardwood forest is associated with declines in belowground carbon pools

Treesearch

Michael S. Strickland; Jayna L. Devore; John C. Maerz; Mark A. Bradford

2010-01-01

Invasive plant species affect a range of ecosystem processes but their impact on belowground carbon (C) pools is relatively unexplored. This is particularly true for grass invasions of forested ecosystems. Such invasions may alter both the quantity and quality of forest floor inputs. Dependent on both, two theories, ‘priming’ and ‘preferential substrate utilization’,...

Mechanical mastication as a fuels treatment in southeastern forests

Treesearch

Jesse K. Kreye; J. Morgan Varner; Leda N. Kobziar

2016-01-01

Mastication is an increasingly common fuels treatment that redistributes ‘‘ladder’’ fuels to the forest floor to reduce vertical fuel continuity, crown fire potential, and fireline intensity. Despite its widespread adoption, it remains unclear how mastication impacts fuels, fire behavior, or plant communities  across Southeastern forest ecosystems. We evaluated these...

Dead Trees Bring Life to Forest Critters

Treesearch

Thomas Nicholls; Mike Ostry

2003-01-01

What good is a dying or dead tree in a forest? Dead and dying trees don't awe us with their beauty; they just stand or lie there on the forest floor, offering no promise of lumber or other wood products we need. But if we look more closely at such trees, we may see lots of life in them: a raccoon family huddled in a burrow, a downy woodpecker excavating another...

Effects of prescribed fire intervals on carbon and nitrogen in forest soils of the Mogollon Rim, Arizona

Treesearch

Daniel G. Neary; Steven T. Overby; Sally M. Haase

2003-01-01

The pre-European settlement ponderosa pine forests of the Mogollon Rim consisted of open stands of uneven-aged trees with a significant grass-forb understory. Light surface-fires occurred on an average interval of 2 to 12 years in Arizona and New Mexico (Dietrich 1980). These fires consumed forest floor material, burned most of the young regeneration, and promoted...

Variability of albedo and utility of the MODIS albedo product in forested wetlands

USGS Publications Warehouse

Sumner, David M.; Wu, Qinglong; Pathak, Chandra S.

2011-01-01

Albedo was monitored over a two-year period (beginning April 2008) at three forested wetland sites in Florida, USA using up- and down-ward facing pyranometers. Water level, above and below land surface, is the primary control on the temporal variability of daily albedo. Relatively low reflectivity of water accounts for the observed reductions in albedo with increased inundation of the forest floor. Enhanced canopy shading of the forest floor was responsible for lower sensitivity of albedo to water level at the most dense forest site. At one site, the most dramatic reduction in daily albedo was observed during the inundation of a highly-reflective, calcareous periphyton-covered land surface. Satellite-based Moderate-Resolution Imaging Spectroradiometer (MODIS) estimates of albedo compare favorably with measured albedo. Use of MODIS albedo values in net radiation computations introduced a root mean squared error of less than 4.7 W/m2 and a mean, annual bias of less than 2.3 W/m2 (1.7%). These results suggest that MODIS-estimated albedo values can reliably be used to capture areal and temporal variations in albedo that are important to the surface energy balance.

Does long-term elevation of CO{sub 2} concentration increase photosynthesis in forest floor vegetation? Indiana strawberry in a Maryland forest

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

Osborne, C.P.; Long, S.P.; Drake, B.G.

1997-05-01

As the partial pressure of CO{sub 2} (pCO{sub 2}) in the atmosphere rises, photorespiratory loss of carbon in C, photosynthesis will diminish and the net efficiency of light-limited photosynthetic carbon uptake should rise. Indiana strawberry (Duchesnea indica) growing on a Maryland forest floor was tested. Open-top chambers were used to elevate the pCO{sub 2} of a forest floor habitat to 67 Pa and were paired with control chambers with an ambient pCO{sub 2} of 38 Pa. After 3.5 years, D. indica leaves in the elevated pCO{sub 2} showed a significantly greater maximum quantum efficiency of net photosynthesis (by 22%) andmore » a lower light compensation point (by 42%) than leaves in the control chambers. The quantum efficiency to minimize photorespiration was the same for controls and plants grown at elevated pCO{sub 2}, showing the maximum efficiency of light-energy transduction into assimilated carbon was not altered by acclimation and the increase in light-limited photosynthesis at elevated pCO{sub 2} was a function of the decrease in photorespiration. Acclimation did decrease the ribulose-1,5-bisphosphate carboxylase/oxygenase and light-harvesting chlorophyll protein content of the leaf by more than 30%. These changes were associated with a decreased capacity for light-saturated, but not light-limited, photosynthesis. Leaves of D. indica grown and measured at elevated pCO{sub 2} showed greater light-saturated photosynthetic rates than leaves grown and measured at the current atmospheric pCO{sub 2}. In situ measurements under natural lighting showed large increases in leaf photosynthesis at elevated pCO{sub 2}, relative to controls, in both summer and fall. The increase in efficiency of light-limited photosynthesis with elevated pCO{sub 2} allowed positive net photosynthetic carbon uptake on days and at locations on the forest floor that light fluxes were insufficient for positive net photosynthesis in the current atmospheric pCO{sub 2}. 33 refs., 3 figs., 3 tabs.« less

Cruising the rain forest floor: butterfly wing shape evolution and gliding in ground effect.

PubMed

Cespedes, Ann; Penz, Carla M; DeVries, Philip J

2015-05-01

Flight is a key innovation in the evolutionary success of insects and essential to dispersal, territoriality, courtship and oviposition. Wing shape influences flight performance and selection likely acts to maximize performance for conducting essential behaviours that in turn results in the evolution of wing shape. As wing shape also contributes to fitness, optimal shapes for particular flight behaviours can be assessed with aerodynamic predictions and placed in an ecomorphological context. Butterflies in the tribe Haeterini (Nymphalidae) are conspicuous members of understorey faunas in lowland Neotropical forests. Field observations indicate that the five genera in this clade differ in flight height and behaviour: four use gliding flight at the forest floor level, and one utilizes flapping flight above the forest floor. Nonetheless, the association of ground level gliding flight behaviour and wing shape has never been investigated in this or any other butterfly group. We used landmark-based geometric morphometrics to test whether wing shapes in Haeterini and their close relatives reflected observed flight behaviours. Four genera of Haeterini and some distantly related Satyrinae showed significant correspondence between wing shape and theoretical expectations in performance trade-offs that we attribute to selection for gliding in ground effect. Forewing shape differed between sexes for all taxa, and male wing shapes were aerodynamically more efficient for gliding flight than corresponding females. This suggests selection acts differentially on male and female wing shapes, reinforcing the idea that sex-specific flight behaviours contribute to the evolution of sexual dimorphism. Our study indicates that wing shapes in Haeterini butterflies evolved in response to habitat-specific flight behaviours, namely gliding in ground effect along the forest floor, resulting in ecomorphological partitions of taxa in morphospace. The convergent flight behaviour and wing morphology between tribes of Satyrinae suggest that the flight environment may offset phylogenetic constraints. Overall, this study provides a basis for exploring similar patterns of wing shape evolution in other taxa that glide in ground effect. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

Quantifying the missing link between forest albedo and productivity in the boreal zone

NASA Astrophysics Data System (ADS)

Hovi, Aarne; Liang, Jingjing; Korhonen, Lauri; Kobayashi, Hideki; Rautiainen, Miina

2016-11-01

Albedo and fraction of absorbed photosynthetically active radiation (FAPAR) determine the shortwave radiation balance and productivity of forests. Currently, the physical link between forest albedo and productivity is poorly understood, yet it is crucial for designing optimal forest management strategies for mitigating climate change. We investigated the relationships between boreal forest structure, albedo and FAPAR using a radiative transfer model called Forest Reflectance and Transmittance model FRT and extensive forest inventory data sets ranging from southern boreal forests to the northern tree line in Finland and Alaska (N = 1086 plots). The forests in the study areas vary widely in structure, species composition, and human interference, from intensively managed in Finland to natural growth in Alaska. We show that FAPAR of tree canopies (FAPARCAN) and albedo are tightly linked in boreal coniferous forests, but the relationship is weaker if the forest has broadleaved admixture, or if canopies have low leaf area and the composition of forest floor varies. Furthermore, the functional shape of the relationship between albedo and FAPARCAN depends on the angular distribution of incoming solar irradiance. We also show that forest floor can contribute to over 50 % of albedo or total ecosystem FAPAR. Based on our simulations, forest albedos can vary notably across the biome. Because of larger proportions of broadleaved trees, the studied plots in Alaska had higher albedo (0.141-0.184) than those in Finland (0.136-0.171) even though the albedo of pure coniferous forests was lower in Alaska. Our results reveal that variation in solar angle will need to be accounted for when evaluating climate effects of forest management in different latitudes. Furthermore, increasing the proportion of broadleaved trees in coniferous forests is the most important means of maximizing albedo without compromising productivity: based on our findings the potential of controlling forest density (i.e., basal area) to increase albedo may be limited compared to the effect of favoring broadleaved species.

Enhanced accumulation and storage of mercury on subtropical evergreen forest floor: Implications on mercury budget in global forest ecosystems

NASA Astrophysics Data System (ADS)

Wang, Xun; Lin, Che-Jen; Lu, Zhiyun; Zhang, Hui; Zhang, Yiping; Feng, Xinbin

2016-08-01

Forest ecosystems play an important role in the global cycling of mercury (Hg). In this study, we characterized the Hg cycling at a remote evergreen broadleaf (EB) forest site in southwest China (Mount Ailao). The annual Hg input via litterfall is estimated to be 75.0 ± 24.2 µg m-2 yr-1 at Mount Ailao. Such a quantity is up to 1 order of magnitude greater than those observed at remote temperate/boreal (T/B) forest sites. Production of litter biomass is found to be the most influential factor causing the high Hg input to the EB forest. Given their large areal coverage, Hg deposition through litterfall in EB forests is appropriately 9 ± 5 Mg yr-1 in China and 1086 ± 775 Mg yr-1 globally. The observed wet Hg deposition at Mount Ailao is 4.9 ± 4.5 µg m-2 yr-1, falling in the lower range of those observed at 49 T/B forest sites in North America and Europe. Given the data, the Hg deposition flux through litterfall is approximately 15 times higher than the wet Hg deposition at Mount Ailao. Steady Hg accumulation in decomposing litter biomass and Hg uptake from the environment were observed during 25 months of litter decomposition. The size of the Hg pool in the organic horizon of EB forest floors is estimated to be up to 2-10 times the typical pool size in T/B forests. This study highlights the importance of EB forest ecosystems in global Hg cycling, which requires further assessment when more data become available in tropical forests.

Do the energy fluxes and surface conductance of boreal coniferous forests in Europe scale with leaf area?

PubMed

Launiainen, Samuli; Katul, Gabriel G; Kolari, Pasi; Lindroth, Anders; Lohila, Annalea; Aurela, Mika; Varlagin, Andrej; Grelle, Achim; Vesala, Timo

2016-12-01

Earth observing systems are now routinely used to infer leaf area index (LAI) given its significance in spatial aggregation of land surface fluxes. Whether LAI is an appropriate scaling parameter for daytime growing season energy budget, surface conductance (G s ), water- and light-use efficiency and surface-atmosphere coupling of European boreal coniferous forests was explored using eddy-covariance (EC) energy and CO 2 fluxes. The observed scaling relations were then explained using a biophysical multilayer soil-vegetation-atmosphere transfer model as well as by a bulk G s representation. The LAI variations significantly alter radiation regime, within-canopy microclimate, sink/source distributions of CO 2 , H 2 O and heat, and forest floor fluxes. The contribution of forest floor to ecosystem-scale energy exchange is shown to decrease asymptotically with increased LAI, as expected. Compared with other energy budget components, dry-canopy evapotranspiration (ET) was reasonably 'conservative' over the studied LAI range 0.5-7.0 m 2 m -2 . Both ET and G s experienced a minimum in the LAI range 1-2 m 2 m -2 caused by opposing nonproportional response of stomatally controlled transpiration and 'free' forest floor evaporation to changes in canopy density. The young forests had strongest coupling with the atmosphere while stomatal control of energy partitioning was strongest in relatively sparse (LAI ~2 m 2 m -2 ) pine stands growing on mineral soils. The data analysis and model results suggest that LAI may be an effective scaling parameter for net radiation and its partitioning but only in sparse stands (LAI <3 m 2 m -2 ). This finding emphasizes the significance of stand-replacing disturbances on the controls of surface energy exchange. In denser forests, any LAI dependency varies with physiological traits such as light-saturated water-use efficiency. The results suggest that incorporating species traits and site conditions are necessary when LAI is used in upscaling energy exchanges of boreal coniferous forests. © 2016 John Wiley & Sons Ltd.

Summer survival of Phytophthora ramorum in California bay laurel leaves

Treesearch

Elizabeth J. Fichtner; David M. Rizzo; Shannon C. Lynch; Jennifer Davidson; Gerri Buckles; Jennifer Parker

2008-01-01

Sudden oak death manifests as non-lethal foliar lesions on bay laurel (Umbellularia californica), which support sporulation and survival of Phytophthora ramorum in forest ecosystems. Infected bay laurel leaves are more likely to abscise than uninfected leaves, resulting in an accumulation of inoculum at the forest floor. The pathogen survives the dry...

Prescribed fire and timber harvesting effects on soil carbon and nitrogen in a pine forest

USDA-ARS?s Scientific Manuscript database

Thinning and prescribed fire are common management tools used to eliminate thick fuel loads that could otherwise facilitate and encourage a more severe catastrophic wildfire. The objective of this study was to quantify the lasting effects of prescribed fire on forest floor and soil nutrients approxi...

Biodiversity and intentional management: a renaissance pathway.

Treesearch

Sally Duncan

1998-01-01

A project in western Washington tries to mimic natural disturbance to create forest structure similar to late-seral stages. A model was developed to identify pathways to achieve this structure with four indices: capacity to support vertebrate diversity, forest floor function, ecological productivity based on tree-using rodents, and production of deer and elk....

Compartmentalization of pathogens in fire-injured trees

Treesearch

Kevin T. Smith

2013-01-01

Wildland fire is an episodic process that greatly influences the composition, structure, and developmental sequence of forests. Most news reports of wildland fire involves blazes fueled by slash, standing dead stems, and snags that reach into tree crowns and burn deeply into the forest floor, causing extensive tree mortality and the eventual replacement of the standing...

Choosing suitable times for prescribed burning in southern New Jersey

Treesearch

S. Little; H. A. Somes; J. P. Allen

1952-01-01

Prescribed burning is useful in managing pine-oak forests in the Pine Region of southern New Jersey. It favors reproduction of pine by preparing suitable seed beds; it checks the development of hardwood reproduction; and it protects against wild fires by reducing the amount of fuel on the forest floor.

Calcium status of the forest floor in red spruce forests of the northeastern U.S. - past, present and future

Treesearch

Mark B. David; Gregory B. Lawrence; Walter C. Shortle; Scott W. Bailey

1996-01-01

Dieback and growth decline of red spruce (Picea rubens) in the eastern U.S. coincides with the period of acidic deposition, and has led to much speculation as to whether this decline is caused by decreased root-available Ca in the soil.

Restoring fire to mixed conifer forests in the Northern Cascades

Treesearch

T. J. Leuschen

1996-01-01

Many of the ponderosa pine (Pinus ponderosa) mixed conifer stands in the Methow Valley of north-central Washington have developed understories of Douglas-fir (Pseudotsuga rnenziesii) as a result of fire exclusion. Most of the forest floor has not yet become cluttered with dead woody fuel. Instead, the live biomass has increased and...

Annual Changes in Forst Floor Weights Under a Southeast Missouri Oak Stand

Treesearch

Robert M. Loomis

1975-01-01

Amount of organic matter on the forest floor under a typical southeast Missouri oak stand varies about 2.1 tons/acre from season of greatest to season to least accumulation. This also corresponds to the amount of annual litter fall. Maximum accumulation of 7.5 tons/acre occured in Novermber after leaf-fall. Summer decomposition is rapid; minimumof 5.4 tons/acre was...

CTEPP STANDARD OPERATING PROCEDURE FOR COLLECTION OF DISLODGEABLE RESIDUES -- PUF ROLLER SAMPLES FOR PERSISTENT ORGANIC POLLUTANTS (SOP-2.18)

EPA Science Inventory

This SOP describes the method to collect transferable residues from indoor floor surfaces. The sampling procedures described are applicable to bare floors or covered floor surfaces, e.g., carpeting and vinyl flooring. The samples will be collected only in the day care centers o...

N-15 tracing helps explaining N leaching losses from contrasting forest ecosystems

NASA Astrophysics Data System (ADS)

Staelens, J.; Rütting, T.; Huygens, D.; Müller, C.; Verheyen, K.; Boeckx, P.

2009-04-01

Despite chronically enhanced nitrogen (N) deposition to forest ecosystems in Europe and NE America, considerable N retention by forests has been observed, reducing N leaching losses. Organic and mineral soil layers typically immobilize more N than the aboveground biomass, but it is unclear which factors determine N retention in forest ecoystems. However, this knowledge is crucial to assess the impact of changing anthropogenic N emissions on future N cycling and N loss of forests. For coniferous and deciduous forest stands at comparable sites, it is known that both N deposition onto the forest floor as well as N loss by leaching below the rooting zone are significantly higher in coniferous stands. In addition, the N loss in coniferous stands is often more enhanced than can be explained by the higher N input only. This suggests lower N retention by coniferous stands, and may be related to differences in litter and soil characteristics, microbial activity, and N uptake by plant roots. To test this hypothesis, we studied the effect of forest type on N retention using 15N tracing techniques: a field tracer experiment and a combination of in situ isotope pool dilution and a tracing model. The N dynamics were examined for two adjacent forest stands (pedunculate oak (Quercus robur L.) and Scots pine (Pinus sylvestris L.)) on a well-drained sandy soil and with a similar stand history, located in a region with high N deposition (Belgium). Input-output N budgets were established by quantifying atmospheric deposition and leaching below the rooting zone, and confirmed the above finding of higher N deposition and disproportionately higher N loss for the pine stand compared to the oak stand. First, the fate of inorganic N within the ecosystems was studied by spraying three pulses of dissolved 15N, either as ammonium or as nitrate, onto the forest floor in 12 plots of 25 m2. The organic and mineral soil layers, tree roots, soil water percolate, ferns, and tree foliage were sampled and analyzed for total N and 15N four times in the year after 15N application. Here we present results of the 15N recovery four months after the first application, and compare the recovery between the two forest stands and the two N treatments. Second, gross N transformation rates in the undisturbed mineral forest soils were determined via 15N pool dilution and advanced trace modelling. Using five spatial replicates per stand, three 15N treatments were applied in the field to 'virtual' soil cores (0-10 cm) that were disturbed only at sampling. Each treatment solution contained ammonium, nitrate, and nitrite, with one of the N forms labelled with 15N at 99% at. excess. Intact soil cores were sampled at six time intervals over a 12-day period, and analyzed for N and 15N content in different mineral and organic pools. The parameters of different simultaneously occurring process rates were optimized using a Markov Chain Monte Carlo algorithm. In both stands, heterotrophic nitrification of the organic soil pool was more important than autotrophic nitrification of ammonium. Significantly different process rates between the two forest stands were found for mineralization, heterotrophic and autotrophic nitrification, and ammonium and nitrate immobilization. Gross mineralization and ammonium immobilization rates were higher in the oak soil than in the pine soil. Gross nitrate production, in contrast, was faster in the pine soil, while nitrate immobilization was slower. These different soil nitrate dynamics likely contribute to the observed higher nitrate leaching loss in the pine than oak stand. In addition to the faster nitrate immobilization in the oak soil, our results strongly suggested the occurrence of a second N-conserving process under oak, i.e. dissimilatory nitrate reduction to ammonium (DNRA). This is unexpected for a temperate forest soil under enhanced N deposition, as this process has mainly been described for unpolluted soils.

Effects of prescribed fire on conditions inside a Cuban parrot (Amazona Leucocephala) surrogate nesting cavity on Great Abaco, Bahamas

Treesearch

Joseph O' Brien; Caroline Stahala; Gina P. Mori; Mac Callaham; Chris M. Bergh

2006-01-01

Cuban Parrots (Amazona leucocephala) on the island of Great Abaco in the Bahamas forage and nest in native pine forests. The population is unique in that the birds nest in limestone solution holes on the forest floor. Bahamian pine forests are fire-dependent with a frequent surface fire regime. The effects of fire on the parrots, especially while nesting, are not well...

Emissions of forest floor and mineral soil carbon, nitrogen and mercury pools and relationships with fire severity for the Pagami Creek Fire in the Boreal Forest of northern Minnesota

Treesearch

Randall K. Kolka; Brian R. Sturtevant; Jessica R. Miesel; Aditya Singh; Peter T. Wolter; Shawn Fraver; Thomas M. DeSutter; Phil A. Townsend

2017-01-01

Forest fires cause large emissions of C (carbon), N (nitrogen) and Hg (mercury) to the atmosphere and thus have important implications for global warming (e.g. via CO2 and N2O emissions), anthropogenic fertilisation of natural ecosystems (e.g. via N deposition), and bioaccumulation of harmful metals in aquatic and...

Estimation of In-canopy Flux Distributions of Reactive Nitrogen and Sulfur within a Mixed Hardwood Forest in Southern Appalachia

NASA Astrophysics Data System (ADS)

Wu, Z.; Walker, J. T.; Chen, X.; Oishi, A. C.; Duman, T.

2017-12-01

Estimating the source/sink distribution and vertical fluxes of air pollutants within and above forested canopies is critical for understanding biological, physical, and chemical processes influencing the soil-vegetation-atmosphere exchange. The vertical source-sink profiles of reactive nitrogen and sulfur were examined using multiple inverse modeling methods in a mixed hardwood forest in the southern Appalachian Mountains where the ecosystem is highly sensitive to loads of pollutant from atmospheric depositions. Measurements of the vertical concentration profiles of ammonia (NH3), nitric acid (HNO3), sulfur dioxide (SO2), and ammonium (NH4+), nitrate (NO3-), and sulfate (SO42-) in PM2.5 were measured during five study periods between May 2015 and August 2016. The mean concentration of NH3 decreased with height in the upper canopy and increased below the understory toward the forest floor, indicating that the canopy was a sink for NH3 but the forest floor was a source. All other species exhibited patterns of monotonically decreasing concentration from above the canopy to the forest floor. Using the measured concentration profiles, we simulated the within-canopy flow fields and estimated the vertical source-sink flux profiles using three inverse approaches: a Eulerian high-order closure model (EUL), a Lagrangian localized near-field (LNF) model, and a new full Lagrangian stochastic model (LSM). The models were evaluated using the within- and above-canopy eddy covariance flux measurements of heat, CO2 and H2O. Differences between models were analyzed and the flux profiles were used to investigate the origin and fate of reactive nitrogen and sulfur compounds within the canopy. The knowledge gained in this study will benefit the development of soil-vegetation-atmosphere models capable of partitioning canopy-scale deposition of nitrogen and sulfur to specific ecosystem compartments.

Impact of forest seral stage on use of ant communities for rapid assessment of terrestrial ecosystem health.

PubMed

Wike, Lynn D; Martin, F Douglas; Paller, Michael H; Nelson, Eric A

2010-01-01

Bioassessment evaluates ecosystem health by using the responses of a community of organisms that integrate all aspects of the ecosystem. A variety of bioassessment methods have been applied to aquatic ecosystems; however, terrestrial methods are less advanced. The objective of this study was to examine baseline differences in ant communities at different seral stages from clear cut to mature pine plantation as a precursor to developing a broader terrestrial bioassessment protocol. Comparative sampling was conducted at nine sites having four seral stages: clearcut, 5 year recovery, 15 year recovery, and mature stands. Soil and vegetation data were also collected at each site. Ants were identified to genus. Analysis of the ant data indicated that ants respond strongly to habitat changes that accompany ecological succession in managed pine forests, and both individual genera and ant community structure can be used as indicators of successional change. Ants exhibited relatively high diversity in both early and mature seral stages. High ant diversity in mature seral stages was likely related to conditions on the forest floor favoring litter dwelling and cold climate specialists. While ants may be very useful in identifying environmental stress in managed pine forests, adjustments must be made for seral stage when comparing impacted and unimpacted forests.

Meta-analysis of radiocesium contamination data in Japanese forest trees over the period 2011-2013.

PubMed

Gonze, M-A; Calmon, P

2017-12-01

The fate and dispersion of radiocesium in forests affected by the Fukushima atmospheric fallouts have been efficiently characterized by Japanese scientists thanks to monitoring surveys of radioactive contents in contaminated soil, water, and vegetation samples at numerous sites. In this paper, we carry out a meta-analysis of the field surveys conducted over the period 2011-2013 in evergreen coniferous and deciduous broadleaf forests of Fukushima or neighboring prefectures. The review focuses on contamination data acquired in tree vegetation - about 1500 spatio-temporal measurements of concentrations, inventories and depuration fluxes - with a particular interest for organs that were directly exposed to the atmospheric fallouts and subjected to depuration mechanisms (foliage, branches and outer bark). To reduce the spatial variability between the sites, radioactive data were normalized by the total deposit estimated at each site. Our analysis highlights the overall consistency of field observations despite the variety of experimental protocols, disparate sampling periods, differences in the forest stand characteristics and variability of the atmospheric deposition conditions. Assuming that the sites conformed to the same dynamics (within the range of residual variability), we then derive, discuss, and compare the mean representative evolutions of radiocesium contamination in the two categories of forest. Thanks to a simple mass balance approach, we finally demonstrate that: (i) about 90% of the radiocesium deposit was intercepted by evergreen coniferous vegetation, (ii) 80% of the deposit was gradually transferred to the forest floor in 3years, according to a well characterized depuration kinetics, and (iii) about 4% was readily absorbed by the foliage and translocated to internal organs (inner bark, stem wood and roots) at a rate of about 10 -4 d -1 . Copyright © 2017 Elsevier B.V. All rights reserved.

Vitality and chemistry of roots of red spruce in forest floors of stands with a gradient of soil Al/Ca ratios in the northeastern United States

USGS Publications Warehouse

Wargo, P.M.; Vogt, K.; Vogt, D.; Holifield, Q.; Tilley, J.; Lawrence, G.; David, M.

2003-01-01

Number of living root tips per branch, percent dead roots, percent mycorrhizae and mycorrhizal morphotype, response of woody roots to wounding and colonization by fungi, and concentrations of starch, soluble sugars, phenols, percent C and N and C/N ratio, and Al Ca, Fe, K, Mg, Mn, and P were measured for 2 consecutive years in roots of red spruce (Picea rubens Sarg.) in stands in the northeastern United States (nine in 1993 and two additional in 1994) dominated by red spruce and with a gradient of forest floor exchangeable Al/Ca ratios. Root vitality was measured for nonwoody and coarse woody roots; chemical variables were measured for nonwoody (<1 mm), fine woody (1 to <2 mm), and coarse woody (2 to <5 mm) roots. There were significant differences among sites for all variables, particularly in 1993, although few were related to the Al/Ca ratio gradient. Percent mycorrhizae decreased, while some morphotypes increased or decreased as the Al/Ca ratio increased. In nonwoody roots, N increased as the Al/Ca ratio increased. Most sampled trees appeared to be in good or fair health, suggesting that an adverse response of these root variables to high Al concentrations may be apparent only after a significant change in crown health.

Soil carbon storage in plantation forests and pastures: land-use change implications

NASA Astrophysics Data System (ADS)

Scott, Neal A.; Tate, Kevin R.; Ford-Robertson, Justin; Giltrap, David J.; Tattersall Smith, C.

1999-04-01

Afforestation may lead to an accumulation of carbon (C) in vegetation, but little is known about changes in soil C storage with establishment of plantation forests. Plantation forest carbon budget models often omit mineral soil C changes from stand-level C budget calculations, while including forest floor C accumulation, or predict continuous soil C increases over several rotations. We used national soil C databases to quantify differences in soil C content between pasture and exotic pine forest plantations dominated by P. radiata (D. Don), and paired site studies to quantify changes in soil C with conversion of pasture to plantation forest in New Zealand. Overall, mineral soil C to 0.10 m was 20 40% lower under pine for all soil types (p<0.01) except soils with high clay activity (HCA), where there was no difference. Similar trends were observed in the 0.1 0.3 m layer. Moreover, mineral soil C to 0.1 m was 17 40% lower under pine than pasture in side-by-side comparisons. The only non-significant difference occurred at a site located on a HCA soil (p=0.08). When averaged across the site studies and the national databases, the difference in soil C between pasture and pine was about 16 t C ha1on non-HCA soils. This is similar to forest floor C averaged across our individual sites (about 20 t C ha1). The decrease in mineral soil C could result in about a 15% reduction in the average C sequestration potential (112 t C ha1) when pasture is converted to exotic plantation forest on non-HCA soils. The relative importance of this change in mineral soil C will likely vary depending on the productivity potential of a site and harvest impacts on the forest floor C pool. Our results emphasize that changes in soil C should be included in any calculations of C sequestration attributed to plantation forestry.

Fuel accumulations in Piedmont loblolly pine plantations

Treesearch

Ernst V. Brender; W. Henry McNab; Shelton Williams

1976-01-01

Weight of minor vegetation under unthinned loblolly pine (Pinus taeda L.) plantations was closely related to stand age and basal area stocking. Weight of this vegetation peaked 3 years after clearcutting and planting, then diminished as the pine canopy became denser. Forest floor weight increased steadily through age 23, when it began to level off. Equilibrium forest...

Estimating soil seed bank characteristics in ponderosa pine forests using vegetation and forest-floor data

Treesearch

Scott R. Abella; Judith D. Springer

2008-01-01

Soil seed banks are important for vegetation management because they contain propagules of species that may be considered desirable or undesirable for site colonization after management and disturbance events. Knowledge of seed bank size and composition before planning management activities facilitates proactive management by providing early alerts of exotic species...

Maintenance and enhancement of long-term multiple socioeconomic benefits to meet the needs of societies

Treesearch

Nianfu Song; Stephen R. Shifley; Michael Bowker; Marla R. Emery; Francisco X. Aguilar; Kenneth E. Skog

2016-01-01

Forests are an important source of timber and nontimber products, recreation, ecological services, and employment in the Northern United States. Timber products are primarily used for building homes; manufacturing flooring, furniture, and cabinets; and making paper and paperboard. Residues from forest harvesting operations and wood processing are used for bioenergy,...

Distinctive fungal and bacterial communities are associated with mats formed by ectomycorrhizal fungi

Treesearch

Laurel A. Kluber; Jane E. Smith; David D. Myrold

2011-01-01

The distinct rhizomorphic mats formed by ectomycorrhizal Piloderma fungi are common features of the organic soil horizons of coniferous forests of the Pacific Northwest. These mats have been found to cover 25-40% of the forest floor in some Douglas-fir stands, and are associated with physical and biochemical properties that distinguish them from...

A throughfall collection method using mixed bed ion exchange resin columns

Treesearch

Mark E. Fenn; Mark A. Poth; Michael J. Arbaugh

2002-01-01

Measurement of ionic deposition in throughfall is a widely used method for measuring deposition inputs to the forest floor. Many studies have been published, providing a large database of throughfall deposition inputs to forests. However, throughfall collection and analysis is labor intensive and expensive because of the large number of replicate collectors needed and...

Characterizing movement of ground-dwelling arthropods with a novel mark-capture method using fluorescent powder

Treesearch

Kayla I. Perry; Kimberly F. Wallin; John W. Wenzel; Daniel A. Herms

2017-01-01

A major knowledge gap exists in understanding dispersal potential of ground-dwelling arthropods, especially in forest ecosystems. Movement of the ground-dwelling arthropod community was quantified using a novel markcapture technique in which three different colored fluorescent powders in two separate mixtures were applied to the floor of a deciduous forest in...

Fuel: Logs, sticks, needles, duff, and much more

Treesearch

Russell T. Graham; Theresa Benevidez Jain; Alan E. Harvey

2000-01-01

Fuels burned by either prescribed or wildfires are complex and important components of forested ecosystems. Fine fuels consisting of fallen limbs, twigs, and leaves of shrubs and trees are rich in nutrients. If these fuels are not immediately burned, nutrients can leach from these materials into the forest floor, especially if they overwinter. Larger fuels consisting...

Linking Soils and Down Woody Material Inventories for Cohesive Assessments of Ecosystem Carbon Pools

Treesearch

Katherine P. O' Neill; Christopher Woodall; Michael Amacher; Geoffrey Holden

2005-01-01

The Soils and Down Woody Materials (DWM) indicators collected by the Forest Inventory and Analysis program provide the only data available for nationally consistent monitoring of carbon storage in soils, the forest floor, and down woody debris. However, these indicators were developed and implemented separately, resulting in field methods and compilation procedures...

Survival, Growth, and Ecosystem Dynamics of Displaced Bromeliads in a Montane Tropical Forest.

Treesearch

Jennifer Pett-Ridge; Whendee L. Silver

2002-01-01

Epiphytes generally occupy arboreal perches, which are inherently unstable environments due to periodic windstorms, branch falls, and treefalls. During high wind events, arboreal bromeliads are often knocked from the canopy and deposited on the forest floor. In this study, we used a common epiphytic tank bromeliad, Guzmania berteroniana (R. & S.) Mez, to determine...

Lessons learned from fire use for restoring southwestern ponderosa pine ecosystems

Treesearch

Stephen S. Sackett; Sally M. Haase; Michael G. Harrington

1996-01-01

Since European settlement, the southwestern ponderosa pine ecosystem has experienced large scale alterations brought about by heavy grazing and timbering and a policy of attempted fire exclusion. These alterations are most evident as large increases in tree numbers and in forest floor organic matter. These changes have resulted in forest health problems, such...

Efficacy of buffer zones in disconnecting roads and streams in the coastal plain

Treesearch

J.M. III Grace; E. Davis

2010-01-01

Established forest BMPs rely heavily on the forest floor to disconnect upslope activities from stream systems. Optimizing the buffer length required to negate the storm runoff contribution of upslope activities has been a point of interest for soil scientist, hydrologist, and conservation professionals for the last century. Minimum buffer lengths have been recommended...

Forest productivity predicts invertebrate biomass and ovenbird (Seriurus Aurocapillus) reproduction in Appalachian landscapes

Treesearch

Steven W. Seagle; Brian R. Sturtevant

2005-01-01

Forest-floor detrital food webs are sustained by annual inputs of leaf fall. However, it is unknown whether this bottom-up effect extends to vertebrates feeding on the detrital food web. We hypothesized that reproductive success of Ovenbirds (Seiurus aurocapillus L.) is a function of acroinvertebrate biomass within the detrital food web, and that...

A BASIS FOR MODIFYING THE TANK 12 COMPOSITE SAMPLING DESIGN

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

Shine, G.

The SRR sampling campaign to obtain residual solids material from the Savannah River Site (SRS) Tank Farm Tank 12 primary vessel resulted in obtaining appreciable material in all 6 planned source samples from the mound strata but only in 5 of the 6 planned source samples from the floor stratum. Consequently, the design of the compositing scheme presented in the Tank 12 Sampling and Analysis Plan, Pavletich (2014a), must be revised. Analytical Development of SRNL statistically evaluated the sampling uncertainty associated with using various compositing arrays and splitting one or more samples for compositing. The variance of the simple meanmore » of composite sample concentrations is a reasonable standard to investigate the impact of the following sampling options. Composite Sample Design Option (a). Assign only 1 source sample from the floor stratum and 1 source sample from each of the mound strata to each of the composite samples. Each source sample contributes material to only 1 composite sample. Two source samples from the floor stratum would not be used. Composite Sample Design Option (b). Assign 2 source samples from the floor stratum and 1 source sample from each of the mound strata to each composite sample. This infers that one source sample from the floor must be used twice, with 2 composite samples sharing material from this particular source sample. All five source samples from the floor would be used. Composite Sample Design Option (c). Assign 3 source samples from the floor stratum and 1 source sample from each of the mound strata to each composite sample. This infers that several of the source samples from the floor stratum must be assigned to more than one composite sample. All 5 source samples from the floor would be used. Using fewer than 12 source samples will increase the sampling variability over that of the Basic Composite Sample Design, Pavletich (2013). Considering the impact to the variance of the simple mean of the composite sample concentrations, the recommendation is to construct each sample composite using four or five source samples. Although the variance using 5 source samples per composite sample (Composite Sample Design Option (c)) was slightly less than the variance using 4 source samples per composite sample (Composite Sample Design Option (b)), there is no practical difference between those variances. This does not consider that the measurement error variance, which is the same for all composite sample design options considered in this report, will further dilute any differences. Composite Sample Design Option (a) had the largest variance for the mean concentration in the three composite samples and should be avoided. These results are consistent with Pavletich (2014b) which utilizes a low elevation and a high elevation mound source sample and two floor source samples for each composite sample. Utilizing the four source samples per composite design, Pavletich (2014b) utilizes aliquots of Floor Sample 4 for two composite samples.« less

137Cs dynamics in the forest of Fukushima after the nuclear power plant accident in March 2011

NASA Astrophysics Data System (ADS)

Endo, I.; Ohte, N.; Iseda, K.; Kobayashi, N.; Hirose, A.; Tanoi, K.

2013-12-01

The accident of Fukushima Daiichi nuclear power plant after the earthquake and Tsunami in March 11th 2011, caused large amount of radioactive Cesium (137Cs) emission into the environment. In the region of Fukushima Prefecture, forest dominates more than 70 % of the land area. River water from the forest area is used for food production and also for drinking water. Thus, it is important to understand the dynamics of 137Cs deposited in the forest to predict how the radioactive Cs diffuse and discharge from the forest catchments. We measured 137Cs concentration of the tree body, litter fall, throughfall, and stemflow, in order to clarify how 137Cs deposited on the above ground biomass of the forest are transported to the forest floor. We set forest site at the upstream part of Kami-Oguni River catchment, northern part of Fukushima Prefecture. Three plots (2 deciduous stands and 1 Japanese cedar (Cryptomeria japonica) plantation stand) were set in the forest site. Quercus serrata and C. japonica, which are representative tree species, were chosen at each plot and concentration of 137Cs on the bark, sapwood and heartwood were measured every 2 m from the ground to tree top. From each plot, 137Cs concentration of leaf litter was measured among species. Water samples of throughfall and stemflow were filtered and 137Cs concentration in suspended matter was measured. 137Cs was deposited on the bark of Q. serrata at high concentration (9-18 kBq/kg) but there were no clear relationship between tree height and concentration. 137Cs concentration of the sapwood (41 Bq/kg) was relatively higher than that of the heartwood (5 Bq/kg). It was suggested that 137Cs may be absorbed from bark and/or root. The concentration of 137Cs deposited in leaf litter varied from non-detected level to above 30 kBq/kg. The concentration was higher at evergreen tree than deciduous tree. It is considered that the litter of evergreen tree was derived from leaves on the tree canopy at the time of the accident. Also, though the leaves of deciduous trees had not been emerged at the time of the accident, significant levels of 137Cs on those leaves suggest that 137Cs may have translocated from some part of tree body. The concentration of 137Cs in rain water was below detection level. However, both throughfall and stemflow contained 137Cs at every plot. From these results, it is suggested that 137Cs deposited on the above ground biomass of the forest continues to move to the forest floor by litter fall and rain event.

Radiocaesium partitioning in Japanese cedar forests following the “early” phase of Fukushima fallout redistribution

PubMed Central

Coppin, Frederic; Hurtevent, Pierre; Loffredo, Nicolas; Simonucci, Caroline; Julien, Anthony; Gonze, Marc-Andre; Nanba, Kenji; Onda, Yuichi; Thiry, Yves

2016-01-01

Our study focused on radiocaesium (137Cs) partitioning in forests, three vegetation periods after the Fukushima Daiichi nuclear power plant accident. 137Cs distribution in forest components (organic and mineral soil layers as well as tree compartments: stem, bark, needles, branches and roots) was measured for two Japanese cedar stand ages (17 and 33 years old). The results showed that around 85% of the initial deposit was found in the forest floor and topsoil. For the youngest stand almost 70% of the deposit is present in the forest floor, whereas for the oldest stand 50% is present in the 0–3 cm mineral soil layer. For trees, old and perennial organs (including dead and living needles and branches, litter fall and outer bark) directly exposed to the fallout remained the most contaminated. The crown concentrated 61–69% of the total tree contamination. Surprisingly the dead organs concentrated 25 ± 9% (young cedars) to 36 ± 20% (mature cedar) of the trees’ residual activity, highlighting the importance of that specific compartment in the early post-accident phase for Japanese cedar forests. Although the stem (including bark) represents the highest biomass pool, it only concentrates 3.3% and 4.6% of the initial 137Cs deposit for mature and young cedars, respectively. PMID:27876870

Involvement of allelopathy in inhibition of understory growth in red pine forests.

PubMed

Kato-Noguchi, Hisashi; Kimura, Fukiko; Ohno, Osamu; Suenaga, Kiyotake

2017-11-01

Japanese red pine (Pinus densiflora Sieb. et Zucc.) forests are characterized by sparse understory vegetation although sunlight intensity on the forest floor is sufficient for undergrowth. The possible involvement of pine allelopathy in the establishment of the sparse understory vegetation was investigated. The soil of the red pine forest floor had growth inhibitory activity on six test plant species including Lolium multiflorum, which was observed at the edge of the forest but not in the forest. Two growth inhibitory substances were isolated from the soil and characterized to be 15-hydroxy-7-oxodehydroabietate and 7-oxodehydroabietic acid. Those compounds are probably formed by degradation process of resin acids. Resin acids are produced by pine and delivered into the soil under the pine trees through balsam and defoliation. Threshold concentrations of 15-hydroxy-7-oxodehydroabietate and 7-oxodehydroabietic acid for the growth inhibition of L. multiflorum were 30 and 10μM, respectively. The concentrations of 15-hydroxy-7-oxodehydroabietate and 7-oxodehydroabietic acid in the soil were 312 and 397μM, respectively, which are sufficient concentrations to cause the growth inhibition because of the threshold. These results suggest that those compounds are able to work as allelopathic agents and may prevent from the invasion of herbaceous plants into the forests by inhibiting their growth. Therefore, allelopathy of red pine may be involved in the formation of the sparse understory vegetation. Copyright © 2017 Elsevier GmbH. All rights reserved.

Chemistry of burning the forest floor during the FROSTFIRE experimental burn, interior Alaska, 1999

USGS Publications Warehouse

Harden, J.W.; Neff, J.C.; Sandberg, D.V.; Turetsky, M.R.; Ottmar, R.; Gleixner, G.; Fries, T.L.; Manies, K.L.

2004-01-01

Wildfires represent one of the most common disturbances in boreal regions, and have the potential to reduce C, N, and Hg stocks in soils while contributing to atmospheric emissions. Organic soil layers of the forest floor were sampled before and after the FROSTFIRE experimental burn in interior Alaska, and were analyzed for bulk density, major and trace elements, and organic compounds. Concentrations of carbon, nutrients, and several major and trace elements were significantly altered by the burn. Emissions of C, N, and Hg, estimated from chemical mass balance equations using Fe, Al, and Si as stable constituents, indicated that 500 to 900 g C and up to 0 to 4 ?? 10-4 g Hg/M2 were lost from the site. Calculations of nitrogen loss range from -4 to +6 g/m2 but were highly variable (standard deviation 19), with some samples showing increased N concentrations post-burn potentially from canopy ash. Noncombustible major nutrients such as Ca and K also were inherited from canopy ash. Thermogravimetry indicates a loss of thermally labile C and increase of lignin-like C in char and ash relative to unburned counterparts. Overall, atmospheric impacts of boreal fires include large emissions of C, N and Hg that vary greatly as a function of severe fire weather and its access to deep organic layers rich in C, N, and Hg. In terrestrial systems, burning rearranges the vertical distribution of nutrients in fuels and soils, the proximity of nutrients and permafrost to surface biota, and the chemical composition of soil including its nutrient and organic constituents, all of which impact C cycling. Copyright 2004 by the American Geophysical Union.

Throughfall and stemflow dynamics in a riparian cedar swamp: possible ecohydrological feedbacks

NASA Astrophysics Data System (ADS)

Duval, T. P.

2012-12-01

Partitioning of rainfall through forest canopies as throughfall and stemflow have deservedly been the subject of much research in the past; however, very little is known about the fluxes of water and solutes through forested wetland communities. Temperate swamps are characterized by intermittent canopy coverage, with areas that are denser than upland forests of similar species, but also contain canopy gaps of meadow and marsh communities,. Understanding the role of vegetation on the distribution of precipitation in these ecosystems is necessary to effectively constrain water balance estimates and predict possible community responses to shifting climate regimes. This study examines throughfall, stemflow, and interception dynamics in a riparian cedar swamp in Alliston, Ontario, Canada over the 2012 growing season. Throughfall averaged 76 % of above-canopy rainfall; however, there were spatial-magnitude interaction variations within the swamp. For events less than 20 mm, between 17 and 75 % of the measured swamp floor received greater depth of rain than above the canopy, whereas for events greater than 20 mm only between 2 and 23 % of the sampled swamp floor received more water than the actual event. The observed spatial variability in throughfall was not related to leaf area index, suggesting remote sensing modelling efforts may not be an accurate method for quantification of wetland precipitation dynamics. Stemflow along the predominantly cedar trees averaged 5 %; therefore, net precipitation on a seasonal basis in this cedar swamp was 81 % of above canopy rainfall. Throughfall DOC and total nitrogen concentrations averaged 31 and 2.2 mg/L, respectively, with stemflow DOC and TN concentrations averaging 109 and 6.5 mg/L, respectively. These values are much higher than reported for upland forest species. In general, throughfall magnitudes increased and solute concentrations decreased with increasing distance from the existing forest boles. The delivery of high reactive-solute concentrations through stemflow and comparatively reduced throughfall water fluxes closer to the trees may represent an ecohydrological feedback to cedar maintenance in swamp ecosystems by enriching the root zone soil with nutrients and shedding water away from the roots in a system where the presence of water is viewed as a stress to optimal growth.

Drier Forest Composition Associated with Hydrologic Change in the Apalachicola River, Florida

USGS Publications Warehouse

Darst, Melanie R.; Light, Helen M.

2008-01-01

Forests of the Apalachicola River floodplain had shorter flood durations, were drier in composition, and had 17 percent fewer trees in 2004 than in 1976. The change to drier forest composition is expected to continue for at least 80 more years. Floodplain drying was caused by large declines in river levels resulting from erosion of the river channel after 1954 and from decreased flows in spring and summer months since the 1970s. Water-level declines have been greatest at low and medium flows, which are the most common flows (occurring about 80 percent of the time). Water levels have remained relatively unchanged during large floods which continue to occur about three times per decade. A study conducted by the U.S. Geological Survey compared temporal changes in hydrologic conditions, forest composition, forest characteristics, and individual species of trees, as well as estimated the potential for change in composition of floodplain forests in the nontidal reach of the Apalachicola River. The study was conducted with the cooperation of the Florida Department of Environmental Protection and the Northwest Florida Water Management District. Forest composition and field observations from studies conducted in 1976-1984 (termed '1976 data') were used as baseline data for comparison with data from plots sampled in 2004-2006 ('2004 data'). Flood durations were shorter in all periods subsequent to 1923-1976. The periods of record used to calculate flood durations for forest data were subsets of the complete record available (1923-2004). At sampled plots in all forest types and reaches combined, flood durations changed an average of more than 70 percent toward the baseline flood duration of the next drier forest type. For all forest types, changes in flood durations toward the next drier type were greatest in the upper reach (95.9 percent) and least in the lower reach (42.0 percent). All forests are expected to be 38.2 percent drier in species composition by 2085, the year when the median age of surviving 2004 subcanopy trees will reach the median age (99 years) of the 2004 large canopy trees. The change will be greatest for forests in the upper reach (45.0 percent). Forest composition changes from pre-1954 to 2085 were calculated using Floodplain Indices from 1976 and 2004 tree-size classes and replicate plots. Species composition in high bottomland hardwood forests is expected to continue to change, and some low bottomland hardwood forests are expected to become high bottomland hardwood forests. Organisms associated with floodplain forests will be affected by the changes in tree species, which will alter the timing of leaf-out, fruiting, and leaf-drop, the types of fruit and debris produced, and soil chemistry. Swamps will contain more bottomland hardwood species, but will also have an overall loss of tree density. The density of trees in swamps significantly decreased by 37 percent from 1976 to 2004. Of the estimated 4.3 million (17 percent) fewer trees that existed in the nontidal floodplain in 2004 than in 1976, 3.3 million trees belonged to four swamp species: popash, Ogeechee tupelo, water tupelo, and bald cypress. Water tupelo, the most important tree in the nontidal floodplain in terms of basal area and density, has declined in number of trees by nearly 20 percent since 1976. Ogeechee tupelo, the species valuable to the tupelo honey industry, has declined in number of trees by at least 44 percent. Greater hydrologic variability in recent years may be the reason swamps have had a large decrease in tree density. Drier conditions are detrimental for the growth of swamp species, and periodic large floods kill invading bottomland hardwood trees. The loss of canopy density in swamps may result in the swamp floor being exposed to more light with an increase in the amount of ground cover present, which in turn, would reduce tree replacement. The microclimate of the swamp floor would become wa

H2O and CO2 fluxes at the floor of a boreal pine forest

NASA Astrophysics Data System (ADS)

Kulmala, Liisa; Launiainen, Samuli; Pumpanen, Jukka; Lankreijer, Harry; Lindroth, Anders; Hari, Pertti; Vesala, Timo

2008-04-01

We measured H2O and CO2 fluxes at a boreal forest floor using eddy covariance (EC) and chamber methods. Maximum evapotranspiration measured with EC ranged from 1.5 to 2.0mmol m-2 s-1 while chamber estimates depended substantially on the location and the vegetation inside the chamber. The daytime net CO2 exchange measured with EC (0-2μmol m-2 s-1) was of the same order as measured with the chambers. The nocturnal net CO2 exchange measured with the chambers ranged from 4 to 7μmol m-2 s-1 and with EC from ~4 to ~5μmol m-2 s-1 when turbulent mixing below the canopy was sufficient and the measurements were reliable. We studied gross photosynthesis by measuring the light response curves of the most common forest floor species and found the saturated rates of photosynthesis (Pmax) to range from 0.008 (mosses) to 0.184μmol g-1 s-1 (blueberry). The estimated gross photosynthesis at the study site based on average leaf masses and the light response curves of individual plant species was 2-3μmol m-2 s-1. At the same time, we measured a whole community with another chamber and found maximum gross photosynthesis rates from 4 to 7μmol m-2 s-1.

Influence of alternative silviculture on small mammals

USGS Publications Warehouse

Waldien, David L.; Hayes, John P.

2006-01-01

HIGHLIGHT: A variety of harvest methods promote diversity within forests while still generating income. For example, recent studies have shown that when dead wood is left on the forest floor during harvest, biodiversity increases. A new Cooperative Forest Ecosystem Research (CFER) program fact sheet summarizes how small mammals respond to dead wood in forests that are harvested with alternative methods. CFER is developing a series of fact sheets about responses to changes in young western Oregon forests. The fact sheets are designed to help resource managers balance management needs, including timber and wildlife. The USGS provides a primary source of financial support for CFER, a consortium of federal and state partners conducting research in support of the Northwest Forest Plan.

Monitoring of environmental conditions in taiga forests using ERS-1 SAR

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

Rignot, E.; Way, J.B.; McDonald, K.

1994-08-01

Synthetic-aperture radar images of forest site near Manley Hot Springs (64[degree]N, 151[degree]W), Alaska, were collected between August 1991 and December 1991, day and night, every 3 days, at C-band frequency ([lambda] = 5.7 cm), vertical receive and transmit polarization, by the European Space Agency First Remote Sensing Satellite, ERS-1. During the same period, air and soil temperatures and dielectric and gravimetric moisture properties of the forest canopy and forest floor were monitored in three forest stands dominated, respectively, by black spruce (Picea mariana), white spruce (Picea glauca), and balsam poplar (Populus balsamifera). The calibrated ERS-1 radar backscatter values, [sigma][degree], ofmore » the forest stands are shown to exhibit a pronounced temporal pattern, with little separability between tree species. The largest change in [sigma][degree], a 3-dB decrease almost independent of tree species, is observed in early winter when the soil and vegetation freeze. In the summer, temporal fluctuations in [sigma][degree] are about 1--2 dB in magnitude, depending on tree species. Diurnal variations in [sigma][degree] are as large as 2 dB during fall freeze-up, and less than 1 dB in summer and winter. These temporal variations in radar backscatter from the forest are interpreted using the MIMICS radar backscatter model and the in situ surface observations as due to changes in the dielectric properties of the forest floor and forest canopy induced by precipitation (summer), drought (fall), and freezing (fall-winter) events. In winter, [sigma][degree] increases across the entire landscape, probably because of volume scattering from large depth hoar ice crystals forming in the snow pack.« less

Fifteen-year patterns of soil carbon and nitrogen following biomass harvesting

Treesearch

Valerie J. Kurth; Anthony W. D' Amato; Brian J. Palik; John B. Bradford

2014-01-01

The substitution of forest-derived woody biofuels for fossil fuel energy has garnered increasing attention in recent years, but information regarding the mid- and long-term effects on soil productivity is limited. We investigated 15-yr temporal trends in forest floor and mineral soil (0-30 cm) C and N pools in response to organic matter removal treatments (OMR; stem-...

Physical properties of forest soils

Treesearch

Charles H. Perry; Michael C. Amacher

2007-01-01

Why Are Physical Properties of the Soil Important? The soil quality indicator, when combined with other data collected by the FIA program, can indicate the current rates of soil erosion, the extent and intensity of soil compaction, and some basic physical properties of the forest floor and the top 20 cm of soil. In this report, two particular physical properties of the...

Estimating ladder fuels: a new approach combining field photography with LiDAR

Treesearch

Heather Kramer; Brandon Collins; Frank Lake; Marek Jakubowski; Scott Stephens; Maggi Kelly

2016-01-01

Forests historically associated with frequent fire have changed dramatically due to fire suppression and past harvesting over the last century. The buildup of ladder fuels, which carry fire from the surface of the forest floor to tree crowns, is one of the critical changes, and it has contributed to uncharacteristically large and severe fires. The abundance of ladder...

Specific gravity relationships in plantation-grown red pine

Treesearch

Gregory Baker; James E. Shottafer

1968-01-01

Norway or red pine (Pinus resinosa Ait.) has been popular in Maine for forest planting because it will rapidly convert grass and weed cover to a forest floor and because it is relatively free from attack by insects and diseases. Since the first commercial thinnings consist of small-sized trees, the most logical market outlet is for pulpwood. Yield of...

Methods for measuring atmospheric nitrogen deposition inputs in arid and montane ecosystems of western North America

Treesearch

M.E. Fenn; J.O. Sickman; A. Bytnerowicz; D.W. Clow; N.P. Molotch; J.E. Pleim; G.S. Tonnesen; K.C. Weathers; P.E. Padgett; D.H. Campbell.

2009-01-01

Measuring atmospheric deposition in arid and snow-dominated regions presents unique challenges. Throughfall, the flux of nutrients transported in solution to the forest floor, is generally the most practical method of estimating below-canopy deposition, particularly when monitoring multiple forest sites or over multiple years. However, more studies are needed to relate...

Effects of tree leaf litter, deer fecal pellets, and soil properties on growth of an introduced earthworm (Lumbricus terrestris): Implications for invasion dynamics

Treesearch

Kassidy N. Yatso; Erik A. Lilleskov

2016-01-01

Invasive earthworm communities are expanding into previously earthworm-free forests of North America, producing profound ecosystem changes. Lumbricus terrestris is an invasive anecic earthworm that consumes a large portion of the detritus on the soil surface, eliminating forest floor organic horizons and reducing soil organic matter. Two mesocosm...

A comparison of the effects of different shelterwood harvest methods on the survival and growth of acorn-origin oak seedlings

Treesearch

Patrick H. Brose

2011-01-01

Timely development of newly germinated oak (Quercus spp.) seedlings into competitive-sized regeneration is an essential part of the oak regeneration process. The amount of sunlight reaching the forest floor partly governs this development, and foresters often use the shelterwood system to expose oak seedlings to varying degrees of insolation. To...

The technique of duff hygrometer calibration

Treesearch

T. Kachin; H. T. Gisborne

1937-01-01

The moisture content of the top layer of coniferous needles and twigs covering the forest floor is one of the factors of forest fire danger which must he determined accurately if fire danger in such timber types is to he measured. As this moisture content cannot he estimated accurately and as a difference of a few per cent of moisture, especially in the lower range,...

Beetle-killed stands in the South Carolina piedmont: from fuel hazards to regenerating oak forests

Treesearch

Aaron D. Stottlemyer; G. Geoff Wang; Thomas A. Waldrop

2012-01-01

Impacts of spring prescribed fire, mechanical mastication, and no-treatment (control) on fuels and natural hardwood tree regeneration were examined in beetle-killed stands in the South Carolina Piedmont. Mechanical mastication ground the down and standing dead trees and live vegetation into mulch and deposited it onto the forest floor. The masticated debris layer had...

Exploring the Woodland Floor

ERIC Educational Resources Information Center

Banner, Pat

1974-01-01

The article discusses the often ignored information that can be discovered by examining ground characteristics in woods and forests. Woodland cycles, the food chain, animal habitats, and nature's recycling are included. (KM)

Yosemite National Park

NASA Image and Video Library

2017-12-08

Naked summits alternate with forested lowlands in Yosemite Valley, part of California’s Yosemite National Park. During the Pleistocene Ice Age, glaciers sculpted the underlying rocks in this region, leaving behind canyons, waterfalls, rugged peaks, and granite domes. As the ice retreated, forests grew, but forests only extend as high as 2,900 meters (9,500 feet) above sea level. Above the tree line are rocky landscapes with sparse alpine vegetation. So from the sky, Yosemite Valley appears as a light-and-dark patchwork of forest, rock, and shadow. The Enhanced Thematic Mapper Plus on NASA’s Landsat 7 satellite captured this true-color image of part of Yosemite Valley on August 18, 2001. The valley runs roughly east-west, and tall granite peaks lining the valley’s southern side cast long shadows across the valley floor. On the valley’s northern side, steep slopes appear almost white. Along the valley floor, roadways form narrow, meandering lines of off-white, past parking lots, buildings, and meadows. On the north side of Yosemite Valley is El Capitan. Shooting straight up more than 915 meters (3,000 feet) above the valley floor, El Capitan is considered the largest granite monolith in the world. This granite monolith sits across the valley from Bridalveil Fall, one of the valley’s most prominent waterfalls. Read more: go.nasa.gov/2bzGo3d Credit: NASA/Landsat7 NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Evaporation components of a boreal forest: variations during the growing season

NASA Astrophysics Data System (ADS)

Grelle, A.; Lundberg, A.; Lindroth, A.; Morén, A.-S.; Cienciala, E.

1997-10-01

To improve the understanding of interactions between the boreal forest and the climate system as a key issue for global climate change, the water budget of a mixed pine and spruce forest in central Sweden was estimated by measurements of the water flux components and the total evaporation flux during the period 16 May-31 October 1995. Total evaporation was measured using eddy correlation and the components were obtained using measurements of precipitation, throughfall, tree transpiration, and forest floor evaporation. On a daily basis, tree transpiration was the dominant evaporation component during the vegetation period. However, it could be efficiently blocked by a wet canopy associated with large interception evaporation. The accumulated total evaporation was 399 mm, transpiration was 243 mm, forest floor evaporation was 56 mm and interception evaporation was 74 mm. The accumulated sum of interception, transpiration, and floor evaporation was 51 mm larger than the actual measured total evaporation. This difference was mainly attributed to the fact that transpiration was measured in a rather dense 50-year-old stand while total evaporation represented the average conditions of older, roughly 100-year-old stands. To compare eddy-correlation measurements with small-scale measurements of evaporation components, a source area analysis was made to select the flux data that give the best representation of the investigated stand. Especially under stable atmospheric conditions the requirements for surface homogeneity were very high and extreme care had to be taken to be aware of the flux source areas. Canopy water storage was determined by two methods: by the water balance of the canopy, which gave a result of 3.3 mm; and by the so-called minimum method based on plots of throughfall versus precipitation, which gave a much lower value of 1.5 mm. Seasonal interception evaporation constituted 30% of the precipitation.

Vertical distribution of soil extractable organic C and N contents and total C and N stocks in 78-year-old tree plantations in subtropical Australia.

PubMed

Zhou, Xiaoqi; Dong, Haibo; Lan, Zhongming; Bacon, Gary; Hao, Yanbin; Chen, Chengrong

2017-10-01

Few studies have focused on the effects of long-term forest plantations on the soil profile of carbon (C) and nitrogen (N) stocks. In this study, we selected 78-year-old tree plantations that included three coniferous tree species (i.e., slash pine, hoop pine and kauri pine) and a Eucalyptus species in subtropical Australia. We measured soil extractable organic C (EOC) and N (EON) contents and total C and N stocks under different tree species on the forest floor and along a soil profile to 100 cm depth. The results showed that Eucalyptus had significantly higher soil EOC contents (3.3 Mg ha -1 ) than the other tree species (EOC of 1.9-2.3 Mg ha -1 ) and had significantly higher EON (156 kg ha -1 ) contents than slash pine (107 kg ha -1 ). Eucalyptus had significantly higher soil C (58.9 Mg ha -1 ) and N (2.03 Mg ha -1 ) stocks than the other tree species (22.3-27.6 Mg C ha -1 and 0.71-1.23 Mg N ha -1 ) at 0-100 cm depth. There were no differences in soil C stocks at the 0-100 cm depth among the coniferous tree species. Forest floor C stocks had stronger effects on mineral soil total N stocks than fine root biomass, whereas fine root biomass exerted stronger effects on soil total C stocks at the 0-100 cm depth than forest floor C and N stocks. Our results addressed large differences in soil C and N stocks under different tree species, which can provide useful information for local forest management practices in this region.

Black carbon content in a ponderosa pine forest of eastern Oregon with varying seasons and intervals of prescribed burns

NASA Astrophysics Data System (ADS)

Matosziuk, L.; Hatten, J. A.

2016-12-01

Soil carbon represents a significant component of the global carbon cycle. While fire-based disturbance of forest ecosystems acts as a carbon source, the increased temperatures can initiate molecular changes to forest biomass that convert fast cycling organic carbon into more stable forms such as black carbon (BC), a product of incomplete combustion that contains highly-condensed aromatic structures and very low hydrogen and oxygen content. Such forms of carbon can remain in the soil for hundred to thousands of years, effectively creating a long-term carbon sink. The goal of this project is to understand how specific characteristics of prescribed burns, specifically the season of burn and the interval between burns, affect the formation, structure, and retention of these slowly degrading forms of carbon in the soil. Both O-horizon (forest floor) and mineral soil (0-15 cm cores) samples were collected from a season and interval of burn study in Malheur National Forest. The study area is divided into six replicate units, each of which is sub-divided into four treatment areas and a control. Beginning in 1997, each treatment area was subjected to: i) spring burns at five-year intervals, ii) fall burns at five-year intervals, iii) spring burns at 15-year intervals, or iv) fall burns at 15-year intervals. The bulk density, pH, and C/N content of each soil were measured to assess the effect of the burn treatments on the soil. Additionally, the amount and molecular structure of BC in each sample was quantified using the distribution of specific molecular markers (benzene polycarboxylic acids or BPCAs) that are present in the soil following acid digestion.

Hydrologic and forest management controls on DOC dynamics in the small watersheds of the H.J. Andrews Experimental Forest, OR

NASA Astrophysics Data System (ADS)

Lajtha, K.; Jones, J. A.

2016-12-01

Dissolved organic carbon (DOC) export from hillslopes to streams is an important component of the carbon cycle of a catchment and may be a critical source of energy for the aquatic food web in receiving waters. Using a long-term record of DOC and other dissolved nutrients and elements from paired watersheds from the H.J. Andrews Experimental Forest in Oregon, we explored hydrologic, climatic, and land-use controls on seasonal and inter-annual patterns of DOC flux in a seasonally dry ecosystem. Seasonal patterns of DOC flux demonstrated source limitations to DOC export, with DOC concentrations highest immediately following the first rains after a dry summer, and lowest after winter rains. In contrast, more geochemically-controlled elements showed simple dilution-concentration patterns with no seasonal hysteresis. Inter-annual patterns of DOC flux, however, did not provide evidence of source limitation, with DOC flux within a watershed tightly correlated to total discharge but not temperature. Among watersheds, forest harvest, even over 50 years ago, significantly reduced DOC flux but not fluxes of other elements including N; this response was linked to the loading of coarse woody debris to the forest floor. Chemical fingerprinting of DOC revealed that old-growth watersheds had higher fluxes of DOC characteristic of forest floor organic materials, likely delivered to streams through more surficial preferential flow pathways not subject to microbial alteration, respiration, or sorption losses. Taken together these results suggest that the biogeochemical composition of forested streams reflects both current hydrologic patterns and also processes that occurred many decades ago within the catchment.

Airborne Laser Scanning of Forest Stem Volume in a Mountainous Environment

PubMed Central

Hollaus, Markus; Wagner, Wolfgang; Maier, Bernhard; Schadauer, Klemens

2007-01-01

Airborne laser scanning (ALS) is an active remote sensing technique that uses the time-of-flight measurement principle to capture the three-dimensional structure of the earth's surface with pulsed lasers that transmit nanosecond-long laser pulses with a high pulse repetition frequency. Over forested areas most of the laser pulses are reflected by the leaves and branches of the trees, but a certain fraction of the laser pulses reaches the forest floor through small gaps in the canopy. Thus it is possible to reconstruct both the three-dimensional structure of the forest canopy and the terrain surface. For the retrieval of quantitative forest parameters such as stem volume or biomass it is necessary to use models that combine ALS with inventory data. One approach is to use multiplicative regression models that are trained with local inventory data. This method has been widely applied over boreal forest regions, but so far little experience exists with applying this method for mapping alpine forest. In this study the transferability of this approach to a 128 km2 large mountainous region in Vorarlberg, Austria, was evaluated. For the calibration of the model, inventory data as operationally collected by Austrian foresters were used. Despite these inventory data are based on variable sample plot sizes, they could be used for mapping stem volume for the entire alpine study area. The coefficient of determination R2 was 0.85 and the root mean square error (RMSE) 90.9 m3ha−1 (relative error of 21.4%) which is comparable to results of ALS studies conducted over topographically less complex environments. Due to the increasing availability, ALS data could become an operational part of Austrian's forest inventories.

Response of soricid populations to repeated fire and fuel reduction treatments in the southern Appalachain Mountains

Treesearch

Charlotte E Matthews; Christopher E Moorman; Cathryn H Greenberg

2009-01-01

Fuel hazards have increased in forests across the United States because offire exclusion during the 20th century. Treatments used to reduce fuel buildup Illay affect wildlife. such as shrews. living 011 the forest floor. especially when treatments are applied repeatedly. From mid-May to mid-August 2006 and 2007.  we used drift fences...

Cost and time study for constructing raised wood floor systems in the Gulf Coast Region of the United States

Treesearch

Marie Del Bianco; David B. McKeever; Lance Barta

2012-01-01

This report is the result of a co-operative effort between the USDA Forest Service, Forest Products Laboratory (FPL) Advanced Housing Research Center, the National Assocation of Home Builders (NAHB) Research Center, and builder members of the Metropolitan Mobile and Baldwin County Home Builders Associations. The study was undertaken to further knowledge that will...

Long-term (13 Years) decomposition rates of forest floor organic matter on paired coniferous and deciduous watersheds with contrasting temperature regimes

Treesearch

Robert G. Qualls

2016-01-01

Two sets of paired watersheds on north and South facing slopes were utilized to simulate the effects of temperature differences that are on the scale of those expected with near-term climatic warming on decomposition. Two watersheds were pine plantations (Pinus strobus L.) and two were mature deciduous forests established at similar elevation...

Estimation of Moisture Content of Forest Canopy and Floor from SAR Data Part II: Trunk-Ground Double-Bounce Case

NASA Technical Reports Server (NTRS)

Moghaddam, M.; Saatchi, S.

1996-01-01

Several scattering mechanisms contribute to the total radar backscatter cross section measured by the synthetic aperture radar. These are volume scattering, trunk-ground double-bounce scattering, branch-ground double-bounce scattering, and surface scattering. All of these mechanisms are directly related to the dielectric constant of forest components responsible for that mechanism and their moisture.

Effects of land use change on soil carbon cycling in the conterminous United States from 1900 to 2050

Treesearch

Peter B. Woodbury; Linda S. Heath; James E. Smith

2007-01-01

We developed matrices representing historical area transitions between forest and other land uses. We projected future transitions on the basis of historical transitions and econometric model results. These matrices were used to drive a model of changes in soil and forest floor carbon stocks. Our model predicted net carbon emission from 1900 until 1982, then...

Wood decomposition following clearcutting at Coweeta Hydrologic Laboratory

Treesearch

Kim G. Mattson; Wayne T. Swank

2014-01-01

Most of the forest on Watershed (WS) 7 was cut and ledt on site to decompose. This Chapter describes the rate and manner of wood decomposition and also quantifies the fluxes from decaying wood to the forest floor on WS 7. In doing so, we make the case that wood and its process of decomposition contributes to ecosystem stability. We also review some of the history of...

Short-term effects of prescribed fire in grand fir-white pine-western hemlock slash fuels

Treesearch

Elizabeth D. Reinhardt; Russell T. Graham; Theresa B. Jain; Dennis G. Simmerman

1994-01-01

Experimental burns were conducted on 36 plots in mixed conifer logging slash in northern Idaho, under varying fuel loadings and moisture conditions. This paper reports the immediate effects of these burns on the forest floor, the woody fuel complex, and the plant community, and includes recommendations to managers for using prescribed fire in this forest type. Much of...

Development of floristic diversity in 10-year-old restoration forests on a bauxite mined site in Amazonia.

Treesearch

J. A. Parrotta; O. H. Knowles; J.M. Wunderle Jr.

1997-01-01

Patterns of plant and animal diversity were studied in a 10-year-old native species reforestation area at a bauxite-mined site at porto Trombetas in western Para State, Brazil. Understorey and overstorey floristic composition and structure, understorey light conditions, forest floor development and soil properties were evaluated in a total of 38 78.5-m2

Changes in water extractable organic matter during incubation of forest floor material in the presence of quartz, goethite and gibbsite surfaces

NASA Astrophysics Data System (ADS)

Heckman, Katherine; Vazquez-Ortega, Angelica; Gao, Xiaodong; Chorover, Jon; Rasmussen, Craig

2011-08-01

The release of dissolved organic matter (DOM) from forest floor material constitutes a significant flux of C to the mineral soil in temperate forest ecosystems, with estimates on the order of 120-500 kg C ha -1 year -1. Interaction of DOM with minerals and metals results in sorptive fractionation and stabilization of OM within the soil profile. Iron and aluminum oxides, in particular, have a significant effect on the quantity and quality of DOM transported through forest soils due to their high surface area and the toxic effects of dissolved aluminum on microbial communities. We directly examined these interactions by incubating forest floor material, including native microbiota, for 154 days in the presence of (1) goethite (α-FeOOH), (2) gibbsite (γ-Al(OH) 3), and (3) quartz (α-SiO 2) sand (as a control). Changes in molecular and thermal properties of water extractable organic matter (WEOM, as a proxy for DOM) were evaluated. WEOM was harvested on days 5, 10, 20, 30, 60, 90, and 154, and examined by thermogravimetry/differential thermal analysis (TG/DTA) and diffuse reflectance Fourier transform infrared (DRIFT) spectroscopy. Results indicated significant differences in WEOM quality among treatments, though the way in which oxide surfaces influenced WEOM properties did not seem to change significantly with increasing incubation time. Dissolved organic C concentrations were significantly lower in WEOM from the oxide treatments in comparison to the control treatment. Incubation with goethite produced WEOM with mid-to-high-range thermal lability that was depleted in both protein and fatty acids relative to the control. The average enthalpy of WEOM from the goethite treatment was significantly higher than either the gibbsite or control treatment, suggesting that interaction with goethite surfaces increases the energy content of WEOM. Incubation with gibbsite produced WEOM rich in thermally recalcitrant and carboxyl-rich compounds in comparison to the control treatment. These data indicate that interaction of WEOM with oxide surfaces significantly influences the composition of WEOM and that oxides play an important role in determining the biogeochemistry of forest soil DOM.

Foliar litter decomposition in an alpine forest meta-ecosystem on the eastern Tibetan Plateau.

PubMed

Yue, Kai; Yang, Wanqin; Peng, Changhui; Peng, Yan; Zhang, Chuan; Huang, Chunping; Tan, Yu; Wu, Fuzhong

2016-10-01

Litter decomposition is a biological process fundamental to element cycling and a main nutrient source within forest meta-ecosystems, but few studies have looked into this process simultaneously in individual ecosystems, where environmental factors can vary substantially. A two-year field study conducted in an alpine forest meta-ecosystem with four litter species (i.e., willow: Salix paraplesia, azalea: Rhododendron lapponicum, cypress: Sabina saltuaria, and larch: Larix mastersiana) that varied widely in chemical traits showed that both litter species and ecosystem type (i.e., forest floor, stream and riparian zone) are important factors affecting litter decomposition, and their effects can be moderated by local-scale environmental factors such as temperature and nutrient availability. Litter decomposed fastest in the streams followed by the riparian zone and forest floor regardless of species. For a given litter species, both the k value and limit value varied significantly among ecosystems, indicating that the litter decomposition rate and extent (i.e., reaching a limit value) can be substantially affected by ecosystem type and the local-scale environmental factors. Apart from litter initial acid unhydrolyzable residue (AUR) concentration and its ratio to nitrogen concentration (i.e., AUR/N ratio), the initial nutrient concentrations of phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were also important litter traits that affected decomposition depending on the ecosystem type. Copyright © 2016 Elsevier B.V. All rights reserved.

Spider foraging strategy affects trophic cascades under natural and drought conditions.

PubMed

Liu, Shengjie; Chen, Jin; Gan, Wenjin; Schaefer, Douglas; Gan, Jianmin; Yang, Xiaodong

2015-07-23

Spiders can cause trophic cascades affecting litter decomposition rates. However, it remains unclear how spiders with different foraging strategies influence faunal communities, or present cascading effects on decomposition. Furthermore, increased dry periods predicted in future climates will likely have important consequences for trophic interactions in detritus-based food webs. We investigated independent and interactive effects of spider predation and drought on litter decomposition in a tropical forest floor. We manipulated densities of dominant spiders with actively hunting or sit-and-wait foraging strategies in microcosms which mimicked the tropical-forest floor. We found a positive trophic cascade on litter decomposition was triggered by actively hunting spiders under ambient rainfall, but sit-and-wait spiders did not cause this. The drought treatment reversed the effect of actively hunting spiders on litter decomposition. Under drought conditions, we observed negative trophic cascade effects on litter decomposition in all three spider treatments. Thus, reduced rainfall can alter predator-induced indirect effects on lower trophic levels and ecosystem processes, and is an example of how such changes may alter trophic cascades in detritus-based webs of tropical forests.

Spider foraging strategy affects trophic cascades under natural and drought conditions

PubMed Central

Liu, Shengjie; Chen, Jin; Gan, Wenjin; Schaefer, Douglas; Gan, Jianmin; Yang, Xiaodong

2015-01-01

Spiders can cause trophic cascades affecting litter decomposition rates. However, it remains unclear how spiders with different foraging strategies influence faunal communities, or present cascading effects on decomposition. Furthermore, increased dry periods predicted in future climates will likely have important consequences for trophic interactions in detritus-based food webs. We investigated independent and interactive effects of spider predation and drought on litter decomposition in a tropical forest floor. We manipulated densities of dominant spiders with actively hunting or sit-and-wait foraging strategies in microcosms which mimicked the tropical-forest floor. We found a positive trophic cascade on litter decomposition was triggered by actively hunting spiders under ambient rainfall, but sit-and-wait spiders did not cause this. The drought treatment reversed the effect of actively hunting spiders on litter decomposition. Under drought conditions, we observed negative trophic cascade effects on litter decomposition in all three spider treatments. Thus, reduced rainfall can alter predator-induced indirect effects on lower trophic levels and ecosystem processes, and is an example of how such changes may alter trophic cascades in detritus-based webs of tropical forests. PMID:26202370

Edge effects on foliar stable isotope values in a Madagascan tropical dry forest.

PubMed

Crowley, Brooke E; McGoogan, Keriann C; Lehman, Shawn M

2012-01-01

Edge effects represent an inevitable and important consequence of habitat loss and fragmentation. These effects include changes in microclimate, solar radiation, or temperature. Such abiotic effects can, in turn, impact biotic factors. They can have a substantial impact on species, communities, and ecosystems. Here we examine clinal variations in stable carbon and nitrogen isotope values for trees along an edge-interior gradient in the dry deciduous forest at Ankarafantsika National Park. We predicted that soil respiration and differences in solar irradiance would result in stratified δ¹³C values where leaves collected close to the forest floor would have lower δ¹³C values than those growing higher up in the canopy. We also anticipated that plants growing at the savannah-forest boundary would have higher δ¹³C and δ¹⁵N values than plants growing in the forest interior. As expected, we detected a small but significant canopy effect. Leaves growing below 2 m from the forest floor exhibit δ¹³C values that are, on average, 1.1‰ lower than those growing above this threshold. We did not, however, find any relationship between foliar δ¹³C and distance from the edge. Unpredictably, we detected a striking positive relationship between foliar δ¹⁵N values and increasing distance into the forest interior. Variability in physiology among species, anthropogenic influence, organic input, and rooting depth cannot adequately explain this trend. Instead, this unexpected relationship most likely reflects decreasing nutrient or water availability, or a shift in N-sources with increasing distance from the savannah. Unlike most forest communities, the trees at Ampijoroa are growing in nutrient-limited sands. In addition to being nutrient poor, these well-drained soils likely decrease the amount of soil water available to forest vegetation. Continued research on plant responses to edge effects will improve our understanding of the conservation biology of forest ecosystems in Madagascar.

Edge Effects on Foliar Stable Isotope Values in a Madagascan Tropical Dry Forest

PubMed Central

Crowley, Brooke E.; McGoogan, Keriann C.; Lehman, Shawn M.

2012-01-01

Edge effects represent an inevitable and important consequence of habitat loss and fragmentation. These effects include changes in microclimate, solar radiation, or temperature. Such abiotic effects can, in turn, impact biotic factors. They can have a substantial impact on species, communities, and ecosystems. Here we examine clinal variations in stable carbon and nitrogen isotope values for trees along an edge-interior gradient in the dry deciduous forest at Ankarafantsika National Park. We predicted that soil respiration and differences in solar irradiance would result in stratified δ13C values where leaves collected close to the forest floor would have lower δ13C values than those growing higher up in the canopy. We also anticipated that plants growing at the savannah-forest boundary would have higher δ13C and δ15N values than plants growing in the forest interior. As expected, we detected a small but significant canopy effect. Leaves growing below 2 m from the forest floor exhibit δ13C values that are, on average, 1.1‰ lower than those growing above this threshold. We did not, however, find any relationship between foliar δ13C and distance from the edge. Unpredictably, we detected a striking positive relationship between foliar δ15N values and increasing distance into the forest interior. Variability in physiology among species, anthropogenic influence, organic input, and rooting depth cannot adequately explain this trend. Instead, this unexpected relationship most likely reflects decreasing nutrient or water availability, or a shift in N-sources with increasing distance from the savannah. Unlike most forest communities, the trees at Ampijoroa are growing in nutrient-limited sands. In addition to being nutrient poor, these well-drained soils likely decrease the amount of soil water available to forest vegetation. Continued research on plant responses to edge effects will improve our understanding of the conservation biology of forest ecosystems in Madagascar. PMID:22973460

Effects of post-hurricane fertilization and debris removal on earthworm abundance and biomass in subtropical forests in Puerto Rico

Treesearch

Grizelle Gonzalez; Y. Li; X. Zou

2007-01-01

Hurricanes are a common disturbance in the Caribbean, striking the island of Puerto Rico on average every 21 years. Hurricane Hugo (1989) distributed the canopy litter onto the forest floor changing the chemistry and quantity of litter inputs to the soil. In this study, we determined the effect of inorganic fertilization on earthworm abundance, biomass, and species...

The role of dead wood in maintaining arthropod diversity on the forest floor

Treesearch

James L. Hanula; Scott Horn; Dale D. Wade

2006-01-01

Dead wood is a major component of forests and contributes to overall diversity, primarily by supporting insects that feed directly on or in it. Further, a variety of organisms benefit by feeding on those insects. What is not well known is how or whether dead wood influences the composition of the arthropod community that is not solely dependent on it as a food...

Wildfire effects on a ponderosa pine ecosystem: An Arizona case study

Treesearch

R. E. Campbell; Jr. Baker; P. F. Ffolliott; F. R. Larson; C. C. Avery

1977-01-01

A wildfire of variable severity swept through 717 acres (290 ha) of ponderosa pine forest in north-central Arizona in May 1972. Where the fire was intense it killed 90% of the small trees and 50% of the sawtimber, burned 2.6 in (6.5 cm) of forest floor to the mineral soil, and induced a water-repellent layer in the sandier soils. The reduced infiltration rates, which...

Aluminum mobilization and calcium depletion in the forest floor of red spruce forests in the northeastern United States

Treesearch

Gregory B. Lawrence; Mark B. David; Walter C. Shortle

1996-01-01

Mechanisms of Ca depletion were investigated as part of a regional study of relations among acidic deposition, soil chemistry and red spruce decline. Comparison with results from studies in the Adirondack Mountains of New York and the White Mountains of New Hampshire indicates that current acid-extractable Ca concentrations in the Oa horizon are less than one-half the...

CO2 Efflux from Shrimp Ponds in Indonesia

PubMed Central

Sidik, Frida; Lovelock, Catherine E.

2013-01-01

The conversion of mangrove forest to aquaculture ponds has been increasing in recent decades. One of major concerns of this habitat loss is the release of stored ‘blue’ carbon from mangrove soils to the atmosphere. In this study, we assessed carbon dioxide (CO2) efflux from soil in intensive shrimp ponds in Bali, Indonesia. We measured CO2 efflux from the floors and walls of shrimp ponds. Rates of CO2 efflux within shrimp ponds were 4.37 kg CO2 m−2 y−1 from the walls and 1.60 kg CO2 m−2 y−1 from the floors. Combining our findings with published data of aquaculture land use in Indonesia, we estimated that shrimp ponds in this region result in CO2 emissions to the atmosphere between 5.76 and 13.95 Tg y−1. The results indicate that conversion of mangrove forests to aquaculture ponds contributes to greenhouse gas emissions that are comparable to peat forest conversion to other land uses in Indonesia. Higher magnitudes of CO2 emission may be released to atmosphere where ponds are constructed in newly cleared mangrove forests. This study indicates the need for incentives that can meet the target of aquaculture industry without expanding the converted mangrove areas, which will lead to increased CO2 released to atmosphere. PMID:23755306

CO₂ efflux from shrimp ponds in Indonesia.

PubMed

Sidik, Frida; Lovelock, Catherine E

2013-01-01

The conversion of mangrove forest to aquaculture ponds has been increasing in recent decades. One of major concerns of this habitat loss is the release of stored 'blue' carbon from mangrove soils to the atmosphere. In this study, we assessed carbon dioxide (CO₂) efflux from soil in intensive shrimp ponds in Bali, Indonesia. We measured CO₂ efflux from the floors and walls of shrimp ponds. Rates of CO₂ efflux within shrimp ponds were 4.37 kg CO₂ m⁻² y⁻¹ from the walls and 1.60 kg CO₂ m⁻² y⁻¹ from the floors. Combining our findings with published data of aquaculture land use in Indonesia, we estimated that shrimp ponds in this region result in CO₂ emissions to the atmosphere between 5.76 and 13.95 Tg y⁻¹. The results indicate that conversion of mangrove forests to aquaculture ponds contributes to greenhouse gas emissions that are comparable to peat forest conversion to other land uses in Indonesia. Higher magnitudes of CO₂ emission may be released to atmosphere where ponds are constructed in newly cleared mangrove forests. This study indicates the need for incentives that can meet the target of aquaculture industry without expanding the converted mangrove areas, which will lead to increased CO₂ released to atmosphere.

Soil charcoal from the plains to tundra in the Colorado Front Range

NASA Astrophysics Data System (ADS)

Sanford, R. L.; Licata, C.

2010-12-01

Throughout the forests of the central Rockies, soil charcoal from Holocene wildfires has been produced in response to wildland natural fire regimes. The extent and spatial distribution of soil charcoal production is poorly documented in this region, especially with regard to forests and shrublands at different elevations. Soil charcoal is a super-passive C pool derived from woody biomass that can be sequestered for millennia in forest soils. Recent research indicates that soil charcoal may promote enhanced soil fertility. Additionally, soil charcoal is an often overlooked component of soil C mass and flux. We hypothesize that differences in forest and shrubland fire regimes over the millennia have resulted in different soil charcoal amounts. Geospatial data were used to locate random sample plots in foothills shrublands (Cercocarpus montanus), and four forest types; ponderosa pine (Pinus ponderosa), Douglas-fir (Pseudotsuga menziesii), lodgepole pine (Pinus contorta) and spruce-fir (Picea engelmannii - Abies lasiocarpa). Sample plots were stratified to occur with the mid 200 m elevation band of each vegetation type with east aspect, and 10-30% slope. Soils were sampled widely at 0-10 cm depth and analyzed for total soil C and soil charcoal C via chemical digestion and dry combustion techniques. Overall, soil charcoal is four times more abundant in spruce-fir forests than in foothills shrublands (1.9 +/- 0.92 Mg C/ha versus 0.54 +/- 0.44 Mg C/ha). Soil charcoal is also abundant in lodgepole pine and ponderosa pine soils (1.4 +/- 1.02 Mg C/ha and 1.4 +/- 0.54 Mg C/ha respectively) but is less plentiful in Douglas-fir soils (1.0 +/- 0.67). Spruce-fir forests have the most above ground biomass, slower decomposition rates and a less frequent mean fire return interval than the other four forests, hence it makes sense that high per-fire rates of charcoal production would occur in the spruce-fir zone, given large amounts of surface fuels at the time of fire. In contrast, low amounts of coarse woody debris in ponderosa, lodgepole, and shrub communities would cause less charcoal to form, despite higher fire frequencies. The Douglas-fir soil charcoal seems anomalously low, but it may reflect a combination of low forest floor woody debris and low fire frequency. Foothills shrublands have the least biomass, comparatively rapid decomposition rates and a more frequent mean fire return interval. We propose that high biomass and slow turnover rates in the spruce-fir forests creates conditions for relatively higher net soil charcoal accumulation.

Effects of Nitrogen Fertilization and Thinning Treatments on Subsurface Soil Carbon and Nitrogen

NASA Astrophysics Data System (ADS)

Gross, C. D.; James, J. N.; Harrison, R. B.

2016-12-01

Increases in intensively managed forest plantations have caused concern for the long-term productivity and sustainability of these stands, as decreased organic matter retention and shorter rotations can substantially impact soil nutrition both in the short- and long-term. This study aims to provide data for regional responses of soil carbon (C) and nitrogen (N) by depth to fertilization and thinning treatments. Soil was sampled at an intensively managed Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantation in northwestern Oregon, USA. Nine 0.2-ha plots were sampled with at least three pits per plot. Management regimes included no treatment (control), fertilization (F+), minimal thinning (mT), repeated thinning (rT), and combination treatments (mTF+ and rTF+). Fertilized plots received a total of 1120 kg N ha-1 as urea over 16 years. Bulk density and chemical analysis samples were taken in the middle of succeeding soil layers at depths of 0.1, 0.2, 0.5, 1.0, and 1.5 m. Forest floor samples were collected from a randomly placed quadrat. Preliminary results show an increase in total soil C and N of 113 and 106%, respectively, on the mTF+ plot compared to a control plot. The subsoil, defined here as below 0.2 m, contained over 50% of both soil C and N on the mTF+ plot and experienced greater C and N increases than the surface soil following treatment. This study demonstrates that forest management practices over a relatively short time span (<30 years) can significantly alter subsoil, which comprises a substantial portion of biologically available C and N in terrestrial ecosystems. Subsoil processes are critical to our understanding of changes in soil quality and our ability to accurately assess changes in soil C and N reservoirs.

Unsupervised learning on scientific ocean drilling datasets from the South China Sea

NASA Astrophysics Data System (ADS)

Tse, Kevin C.; Chiu, Hon-Chim; Tsang, Man-Yin; Li, Yiliang; Lam, Edmund Y.

2018-06-01

Unsupervised learning methods were applied to explore data patterns in multivariate geophysical datasets collected from ocean floor sediment core samples coming from scientific ocean drilling in the South China Sea. Compared to studies on similar datasets, but using supervised learning methods which are designed to make predictions based on sample training data, unsupervised learning methods require no a priori information and focus only on the input data. In this study, popular unsupervised learning methods including K-means, self-organizing maps, hierarchical clustering and random forest were coupled with different distance metrics to form exploratory data clusters. The resulting data clusters were externally validated with lithologic units and geologic time scales assigned to the datasets by conventional methods. Compact and connected data clusters displayed varying degrees of correspondence with existing classification by lithologic units and geologic time scales. K-means and self-organizing maps were observed to perform better with lithologic units while random forest corresponded best with geologic time scales. This study sets a pioneering example of how unsupervised machine learning methods can be used as an automatic processing tool for the increasingly high volume of scientific ocean drilling data.

Characterizing Hydrological Processes in Vadose Zone by Direct Infiltration Water Sampling.

NASA Astrophysics Data System (ADS)

Mori, Y.; Higashi, N.; Somura, H.; Takeda, I.; Inoue, M.

2007-12-01

These days, planted forest mountainside was roughly maintained due to the population descent and small birth rate. Because thinning operation would delayed, forest was always dark and floor weed was rare. Management induced non point source pollution like surface soil erosion was suspected, however, we could not approach to the source with the stream water analysis. Therefore, direct soil water sampling device using glass fiber capillary force was developed to examine hydrological processes in watershed. In our design, water was collected just by the capillary force and let the excess water down through so that infiltration water was truly sampled and solute concentration kept the same quality as in soil water. The experiment was conducted at two neighboring Japanese cedar planted forest under different management, i.e., south slope was roughly maintained and west slope was well maintained by thinning operation. Load discharges were higher in south slope and lower in west slope. Infiltration water analysis revealed that ion concentration was gradually decreased at west slope, however in south slope, it dropped to lower level in soil water and increased again in stream water. The trend showed that soil buffering function was poor in south slope. Actually, disk permeameter survey revealed that hydraulic conductivity was small in south slope; TOC and biological activity were lower. This entire soil environment explained the water environmental differences in stream water. Because changes in soil environment affects water environment in the future, monitoring or examination of soil environment was considered as preventive measure for environmentally sound water and solute circulation in watershed.

Variations in soil carbon sequestration and their determinants along a precipitation gradient in seasonally dry tropical forest ecosystems.

PubMed

Campo, Julio; Merino, Agustín

2016-05-01

The effect of precipitation regime on the C cycle of tropical forests is poorly understood, despite the existence of models that suggest a drier climate may substantially alter the source-sink function of these ecosystems. Along a precipitation regime gradient containing 12 mature seasonally dry tropical forests growing under otherwise similar conditions (similar annual temperature, rainfall seasonality, and geological substrate), we analyzed the influence of variation in annual precipitation (1240 to 642 mm) and duration of seasonal drought on soil C. We investigated litterfall, decomposition in the forest floor, and C storage in the mineral soil, and analyzed the dependence of these processes and pools on precipitation. Litterfall decreased slightly - about 10% - from stands with 1240 mm yr(-1) to those with 642 mm yr(-1), while the decomposition decreased by 56%. Reduced precipitation strongly affected C storage and basal respiration in the mineral soil. Higher soil C storage at the drier sites was also related to the higher chemical recalcitrance of litter (fine roots and forest floor) and the presence of charcoal across sites, suggesting an important indirect influence of climate on C sequestration. Basal respiration was controlled by the amount of recalcitrant organic matter in the mineral soil. We conclude that in these forest ecosystems, the long-term consequences of decreased precipitation would be an increase in organic layer and mineral soil C storage, mainly due to lower decomposition and higher chemical recalcitrance of organic matter, resulting from changes in litter composition and, likely also, wildfire patterns. This could turn these seasonally dry tropical forests into significant soil C sinks under the predicted longer drought periods if primary productivity is maintained. © 2016 John Wiley & Sons Ltd.

6. FRONT PORCH AND GABLE SHOWING PINE TREE SILHOUETTE, TIMBER ...

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

6. FRONT PORCH AND GABLE SHOWING PINE TREE SILHOUETTE, TIMBER SUPPORTS, AND STONE PORCH FLOOR, TO NORTHWEST - U.S. Forest Service Chelan Ranger Station, Main Office, 428 West Woodin Avenue, Chelan, Chelan County, WA

Tree species related functional properties of dissolved and total organic matter in throughfall, stemflow and forest floor solutions

NASA Astrophysics Data System (ADS)

Michalzik, Beate; Bischoff, Sebastian; Schwarz, Martin; Siemens, Jan; Thieme, Lisa; Wilcke, Wolfgang

2016-04-01

The amount and chemical nature of water-bound organic matter is a prerequisite for advancing our understanding of the C and nutrient cycling and associated ecosystem processes. While many investigations have addressed the nature and dynamics of DOM in terrestrial ecosystems, only a few have investigated the dynamics and composition of water-bound total OM (TOM) including the particulate organic matter fraction (POM; 0.45 μm < POM < 500 μm). Since water-bound element and nutrient concentrations are conventionally measured after 0.45 μm-filtration, the exclusion of the POM fraction results in misleading inferences and budgeting gaps of nutrient and energy fluxes in terrestrial ecosystems. Furthermore, tree species differ in leaf composition (e.g. nutrient, polyphenols content) and leaf litter quality, which in turn affect a variety of ecosystem processes. Nevertheless, the composition and amount of DOM and TOM derived from living plant material via throughfall (TF), stemflow (SF) and its compositional fate traversing the forest floor (FF) are insufficiently understood. In particular we asked: How do tree species and forest types affect the amount of dissolved and particulate C and N in TF and FF solutions and thus the input into the mineral soil? Do functional properties (e.g. aromaticity) of DOM and TOM differ in TF, SF and FF solutions collected in beech and spruce stands and among different beech stands across Germany? To monitor (mineral) soil input fluxes of DOM and POM in different spruce and beech forests, we fortnightly sampled TF and FF solution over three years (2010-2012) in the "Hainich-Dün-Exploratory", Thuringia, Central Germany, which forms part of the DFG SPP 1374 "Exploratories for Large-scale and Long-term Functional Biodiversity Research". To characterize chemical properties of DOM and TOM, we applied solid-state 13C NMR spectroscopy to TF, SF and FF solutions from three European beech regions across Germany and from Norway spruce sites of the Hainich-Dün-Exploratory. Fluxes of POC and PN were highly variable between years and added significantly to the annual budgets of DOC and DN in TF and FF solutions especially in beech forests. The non-consideration of these particle-bound element fluxes remarkable underestimates the TOC input to the soil by 30 to 40% and those of TN by 10 to 20%. We therefore emphasize the imperative to include POC and PN fluxes into C and N budgeting of forest ecosystems. 13C NMR spectroscopy revealed remarkable tree-species related differences in the composition of DOM and TOM. Compared to DOM, TOM generally showed higher intensities for the alkyl C region and lower ones for lignin-derived and aromatic C of the aryl C region resulting in lower aromaticity indices and a diminished degree of humification. Differences in the structural composition of DOM and TOM under beech lessened in the order: throughfall > stemflow > forest floor leachate. Compared to spruce, TF DOM under beech concordantly showed the highest intensities of aromatic and phenolic C and lowest ones of alkyl-C. Phenolic compounds are known for their allelopathic potential successfully impairing competing plants and hence altering ecosystem structure and functions - mechanisms being still imperfectly understood.

Associations of phthalate concentrations in floor dust and multi-surface dust with the interior materials in Japanese dwellings.

PubMed

Ait Bamai, Yu; Araki, Atsuko; Kawai, Toshio; Tsuboi, Tazuru; Saito, Ikue; Yoshioka, Eiji; Kanazawa, Ayako; Tajima, Shuji; Shi, Cong; Tamakoshi, Akiko; Kishi, Reiko

2014-01-15

Phthalates are widely used as plasticizers in numerous products. However, there has been some concern about the various effects they may have on human health. Thus, household phthalate levels are an important public health issue. While many studies have assessed phthalate levels in house dust, the association of these levels with building characteristics has scarcely been examined. The present study investigated phthalate levels in house dust samples collected from the living areas of homes, and examined associations between these phthalate levels and the interior materials. Dust was collected from two portions of the living area: floor dust from the entire floor surface, and multi-surface dust from objects more than 35 cm above the floor. The levels of seven phthalates were measured using gas chromatography/mass spectrometry in selective ion monitoring mode. Phthalate levels were higher in multi-surface dust than in floor dust. Among floor dust samples, those from dwellings with compressed wooden flooring had significantly higher levels of di-iso-butyl phthalate compared to those with other floor materials, while polyvinyl chloride (PVC) flooring was associated with higher di-2-ethylhexyl phthalate (DEHP) levels. Among multi-surface dust samples, higher levels of DEHP and di-iso-nonyl phthalate (DINP) were found in samples from homes with PVC wallpaper than without. The number of PVC interior materials was significantly positively correlated with the levels of DEHP and DINP in multi-surface dust. The phthalate levels in multi-surface dust were associated with the interior surface materials, and those in floor dust were directly related to the flooring materials. Our findings show that when using house dust as an exposure assessment, it is very important to note where the samples were collected from. The present report provides useful information about the association between phthalates and dust inside dwellings, which will assist with establishing public health provisions. © 2013. Published by Elsevier B.V. All rights reserved.

Sensitivity of the boreal forest-mire ecotone CO2, CH4, and N2O global warming potential to rainy and dry weather

NASA Astrophysics Data System (ADS)

Ťupek, Boris; Minkkinen, Kari; Vesala, Timo; Nikinmaa, Eero

2015-04-01

In a mosaic of well drained forests and poorly drained mires of boreal landscape the weather events such as drought and rainy control greenhouse gas dynamics and ecosystem global warming potential (GWP). In forest-mire ecotone especially in ecosystems where CO2 sink is nearly balanced with CO2 source, it's fairly unknown whether the net warming effect of emissions of gases with strong radiative forcing (CH4 and N2O) could offset the net cooling effect of CO2 sequestration. We compared the net ecosystem CO2 exchange (NEE) estimated from the carbon sequestrations of forest stands and forest floor CO2 fluxes against CH4 and N2O fluxes of nine forest/mire site types along the soil moisture gradient in Finland. The ground water of nine sites changed between 10 m in upland forests and 0.1 m in mires, and weather during three years ranged between exceptionally wet and dry for the local climate. The NEE of upland forests was typically a sink of CO2, regardless the weather. Though, xeric pine forest was estimated to be a source of CO2 during wet and intermediate year and became a weak sink only in dry year. The NEE of forest-mire transitions ranged between a sink in dry year, while increased stand carbon sequestration could offset the reduced forest floor CO2 emission, and a source in wet year. The NEE of two sparsely forested mires strongly differed. The lawn type mire was balanced around zero and the hummock type mire was relatively strong NEE sink, regardless the weather. Generally, nearly zero N2O emission could not offset the cooling effect of net CH4 sink and net CO2 sink of upland forest and forest-mire transitions. However in sparsely forested mires, with N2O emission also nearly zero, the CH4 emission during wet and intermediate year played important role in turning the net cooling effect of NEE into a net warming. When evaluating GWP of boreal landscapes, undisturbed forest-mire transitions should be regarded as net cooling ecosystems instead of hotspots of net warming.

Microbial Mechanisms Mediating Increased Soil C Storage under Elevated Atmospheric N Deposition

PubMed Central

Freedman, Zachary; Zak, Donald R.; Xue, Kai; He, Zhili; Zhou, Jizhong

2013-01-01

Future rates of anthropogenic N deposition can slow the cycling and enhance the storage of C in forest ecosystems. In a northern hardwood forest ecosystem, experimental N deposition has decreased the extent of forest floor decay, leading to increased soil C storage. To better understand the microbial mechanisms mediating this response, we examined the functional genes derived from communities of actinobacteria and fungi present in the forest floor using GeoChip 4.0, a high-throughput functional-gene microarray. The compositions of functional genes derived from actinobacterial and fungal communities was significantly altered by experimental nitrogen deposition, with more heterogeneity detected in both groups. Experimental N deposition significantly decreased the richness and diversity of genes involved in the depolymerization of starch (∼12%), hemicellulose (∼16%), cellulose (∼16%), chitin (∼15%), and lignin (∼16%). The decrease in richness occurred across all taxonomic groupings detected by the microarray. The compositions of genes encoding oxidoreductases, which plausibly mediate lignin decay, were responsible for much of the observed dissimilarity between actinobacterial communities under ambient and experimental N deposition. This shift in composition and decrease in richness and diversity of genes encoding enzymes that mediate the decay process has occurred in parallel with a reduction in the extent of decay and accumulation of soil organic matter. Our observations indicate that compositional changes in actinobacterial and fungal communities elicited by experimental N deposition have functional implications for the cycling and storage of carbon in forest ecosystems. PMID:23220961

Shift from ecosystem P to N limitation at precipitation gradient in tropical dry forests at Yucatan, Mexico

NASA Astrophysics Data System (ADS)

Campo, Julio

2016-09-01

The effect of precipitation regime on N and P cycles in tropical forests is poorly understood, despite global climate models project total precipitation reductions during the 21st Century. I investigated the influence of variation in annual precipitation (1240-642 mm yr-1) on N and P intra-system cycling along a precipitation regime gradient at Yucatan including 12 mature, tropical dry forests (TDFs) growing under otherwise similar conditions (similar annual temperature, rainfall seasonality and geological substrate). I analyzed N and P storage and turnover in the forest floor and mineral soil and explored the dependence of these processes and pools on precipitation level. The study findings indicate that with decreasing precipitation the litterfall decreases slightly (10%), while nutrient use efficiency increases by 20% for N, and by 40% for P. Decomposition rate and nutrient release was smallest in the dry extremity of precipitation regime. The difference between N and P turnover times in the forest floor and in organic matter indicates that different nutrients control the ecosystem function across the precipitation gradient. The data from this study reveals a pattern of limitation shifting from P towards N with decreasing annual precipitation. I suggest that the long-term consequences of the expected decrease in precipitation in many tropical dry regions would changes N and P supply could have long-term negative effects on primary productivity and future carbon storage in TDFs.

Unearthing Secrets of the Forest

USGS Publications Warehouse

Beldin, Sarah I.; Perakis, Steven S.

2009-01-01

Forests are a defining feature for large areas of the Pacific northwestern United States from northern California to Alaska. Coniferous temperate rainforests in the western Cascade and coastal mountain ranges are appreciated for their aesthetic value and abundant natural resources. Few people recognize the riches beneath the forest floor; yet, soil is a key ecosystem component that makes each type of forest unique. Soils harbor immense biological diversity and control the release of water and nutrients that support life above ground. Understanding how carbon and nutrients cycle in forests, known as forest biogeochemistry, is crucial for evaluating forest productivity, composition, diversity, and change. At the U.S. Geological Survey (USGS) Forest and Rangeland Ecosystem Science Center, research in the Terrestrial Ecosystems Laboratory focuses on nutrient cycling in five themes: climate change, nutrition and sustainability, fire effects, restoration, and forest-stream linkages. This research is essential to understand the entire forest ecosystem and to use the best science available to make informed policy and management decisions.

Strip Clearcutting Did Not Degrade the Site in a Spruce-Fir Forest in Central Maine

Treesearch

Miroslaw M. Czapowskyi; Robert V. Rourke; Robert M. Frank

1977-01-01

Changes in the nutrient concentration in the forest floor and in the mineral soil were assessed on a mature spruce-fir stand in central Maine that had been harvested in 1965 by strip clearcutting. On part of the site, slash was left in place; on other parts it was removed, and on some it was burned. Eight years after the harvest, the clearcut areas tended to have...

Amounts and spatial distribution of downed woody debris, snags, windthrow, and forest floor mass within streamside management zones occurring in shortleaf pine stands five years after harvesting

Treesearch

Hal Liechty

2007-01-01

Shortleaf pine (Pinus echinata Mill.) is a dominant tree species in pine and pine-hardwood forest communities located on ridges and upper- to mid-slope positions in the Ouachita Mountains. The stream reaches located in these stands flow infrequently and are classified as ephemeral or intermittent, have low stream orders, and have relatively narrow...

Side-scan sonar and submersible observations: New techniques for gleaning more information from sea-floor outcrops

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

Kendall, J.; Hams, J.E.; Buck, S.P.

1990-05-01

Advances in high resolution side-scan sonar imaging technology are so effective at imaging sea-floor geology that they have greatly improved the efficiency of a bottom sampling program The traditional sea-floor geology methodology of shooting a high-resolution seismic survey and sampling along the seismic grid was considered successful if outcrops were sampled on 20% of the attempts. A submersible was used sparingly because of the inability to consistently locate sea-floor outcrops. Side-scan sonar images have increased the sampling success ratio to 70-95% and allow the cost-effective use of a submersible even in areas of sparse sea-floor outcrops. In offshore basins thismore » new technology has been used in consolidated and semiconsolidated rock terranes. When combined with observations from a two-man submersible, SCUBA traverses, seismic data, and traditional sea-floor bottom sampling techniques, enough data are provided to develop an integrated sea-floor geologic interpretation. On individual prospects, side-scan sonar has aided the establishment of critical dip in poor seismic data areas, located seeps and tar mounds, and determined erosional breaching of a prospect. Over a mature producing field, side-scan sonar has influenced the search for field extension by documenting the orientation and location of critical trapping cross faults. These relatively inexpensive techniques can provide critical data in any marine basin where rocks crop out on the sea floor.« less

Where Occupation and Environment Overlap: US Forest Service Worker Exposure to Libby Amphibole Fibers

PubMed Central

Harper, Martin; Butler, Corey; Berry, David; Wroble, Julie

2015-01-01

The National Institute for Occupational Safety and Health (NIOSH) conducted an evaluation of exposures to asbestiform amphibole, known as Libby Amphibole (LA), to personnel from the US Department of Agriculture-Forest Service (USFS) working in the Kootenai National Forest near a former vermiculite mine close to Libby, Montana. LA is associated with vermiculite that was obtained from this mine; mining and processing over many years have resulted in the spread of LA into the surrounding Kootenai Forest where it has been found in tree bark, soil, and forest floor litter. As a result of this and other contamination, Libby and surrounding areas have been designated a “Superfund” site by the US Environmental Protection Agency (EPA). This article describes the application of EPA methods for assessing cancer risks to NIOSH sampling results. Phase-contrast microscopy for airborne asbestos fiber evaluation was found to be less useful than transmission electron microscopy in the presence of interfering organic (plant) fibers. NIOSH Method 7402 was extended by examination of larger areas of the filter, but fiber counts remained low. There are differences between counting rules in NIOSH 7402 and the ISO method used by EPA but these are minor in the context of the uncertainty in concentration estimates from the low counts. Estimates for cancer risk are generally compatible with those previously estimated by the EPA. However, there are limitations to extrapolating these findings of low risk throughout the entire area and to tasks that were not evaluated. PMID:25715191

Where occupation and environment overlap: US Forest Service worker exposure to Libby Amphibole fibers.

PubMed

Harper, Martin; Butler, Corey; Berry, David; Wroble, Julie

2015-01-01

The National Institute for Occupational Safety and Health (NIOSH) conducted an evaluation of exposures to asbestiform amphibole, known as Libby Amphibole (LA), to personnel from the US Department of Agriculture-Forest Service (USFS) working in the Kootenai National Forest near a former vermiculite mine close to Libby, Montana. LA is associated with vermiculite that was obtained from this mine; mining and processing over many years have resulted in the spread of LA into the surrounding Kootenai Forest where it has been found in tree bark, soil, and forest floor litter. As a result of this and other contamination, Libby and surrounding areas have been designated a "Superfund" site by the US Environmental Protection Agency (EPA). This article describes the application of EPA methods for assessing cancer risks to NIOSH sampling results. Phase-contrast microscopy for airborne asbestos fiber evaluation was found to be less useful than transmission electron microscopy in the presence of interfering organic (plant) fibers. NIOSH Method 7402 was extended by examination of larger areas of the filter, but fiber counts remained low. There are differences between counting rules in NIOSH 7402 and the ISO method used by EPA but these are minor in the context of the uncertainty in concentration estimates from the low counts. Estimates for cancer risk are generally compatible with those previously estimated by the EPA. However, there are limitations to extrapolating these findings of low risk throughout the entire area and to tasks that were not evaluated.

Stanley Corrsin Award Talk: Fluid Mechanics of Fungi and Slime

NASA Astrophysics Data System (ADS)

Brenner, Michael

2013-11-01

There are interesting fluid mechanics problems everywhere, even in the most lowly and hidden corners of forest floors. Here I discuss some questions we have been working on in recent years involving fungi and slime. A critical issue for the ecology of fungi and slime is nutrient availability: nutrient sources are highly heterogeneous, and strategies are necessary to find food when it runs out. In the fungal phylum Ascomycota, spore dispersal is the primary mechanism for finding new food sources. The defining feature of this phylum is the ascus, a fluid filled sac from which spores are ejected, through a build up in osmotic pressure. We outline the (largely fluid mechanical) design constraints on this ejection strategy, and demonstrate how it provides strong constraints for the diverse morphologies of spores and asci found in nature. The core of the argument revisits a classical problem in elastohydrodynamic lubrication from a different perspective. A completely different strategy for finding new nutrient is found by slime molds and fungi that stretch out - as a single organism- over enormous areas (up to hectares) over forest floors. As a model problem we study the slime mold Physarum polycephalum, which forages with a large network of connected tubes on the forest floors. Localized regions in the network find nutrient sources and then pump the nutrients throughout the entire organism. We discuss fluid mechanical mechanisms for coordinating this transport, which generalize peristalsis to pumping in a heterogeneous network. We give a preliminary discussion to how physarum can detect a nutrient source and pump the nutrient throughout the organism.

A comparison of measured HONO uptake and release with calculated source strengths in a heterogeneous forest environment

NASA Astrophysics Data System (ADS)

Sörgel, Matthias; Trebs, Ivonne; Wu, Dianming; Held, Andreas

2015-04-01

Vertical mixing ratio profiles of nitrous acid (HONO) were measured in a clearing and on the forest floor in a rural forest environment (in the south-east of Germany) by applying a lift system to move the sampling unit of the LOng Path Absorption Photometer (LOPAP) up and down. For the forest floor, HONO was found to be predominantly deposited, whereas net deposition was dominating in the clearing only during nighttime and net emissions were observed during daytime. For selected days, net fluxes of HONO were calculated from the measured profiles using the aerodynamic gradient method. The emission fluxes were in the range of 0.02 to 0.07 nmol m-2 s-1, and, thus were in the lower range of previous observations. These fluxes were compared to the strengths of postulated HONO sources and to the amount of HONO needed to sustain photolysis in the boundary layer. Laboratory measurements of different soil samples from both sites revealed an upper limit for soil biogenic HONO emission fluxes of 0.025 nmol m-2 s-1. HONO formation by light induced NO2 conversion was calculated to be below 0.03 nmol m-2 s-1 for the investigated days, which is comparable to the potential soil fluxes. Due to light saturation at low irradiance, this reaction pathway was largely found to be independent of light intensity, i.e. it was only dependent on ambient NO2. We used three different approaches based on measured leaf nitrate loadings for calculating HONO formation from HNO3 photolysis. While the first two approaches based on empirical HONO formation rates yielded values in the same order of magnitude as the estimated fluxes, the third approach based on available kinetic data of the postulated pathway failed to produce noticeable amounts of HONO. Estimates based on reported cross sections of adsorbed HNO3 indicate that the lifetime of adsorbed HNO3 was only about 15 min, which would imply a substantial renoxification. Although the photolysis of HNO3 was significantly enhanced at the surface, the subsequent light induced conversion of the photolysis product NO2 did not produce considerable amounts of HONO. Consequently, this reaction might occur via an alternative mechanism. Therefore, the semi-volatile weak acid HONO can serve as an example for the complexity of exchange processes as multiple sources and sinks are coexisting, such as (photo-) chemical formation, microbial formation, adsorption/desorption and (stomatal-) uptake.

Oil road effects on the anuran community of a high canopy tank bromeliad (Aechmea zebrina) in the upper Amazon basin, Ecuador.

PubMed

McCracken, Shawn F; Forstner, Michael R J

2014-01-01

Tropical forest canopies are among the most species-rich terrestrial habitats on earth and one of the remaining relatively unexplored biotic frontiers. Epiphytic bromeliads provide microhabitat for a high diversity of organisms in tropical forest canopies and are considered a keystone resource. A number of amphibians inhabit these phytotelmata, yet their ecological role and status in forest canopies remains unknown. For this study, anurans were collected from an upper canopy tank bromeliad (Aechmea zebrina) at ∼20-45 m (x¯ = 33 m) above the forest floor. Bromeliads were sampled from trees located near trails in undisturbed primary rainforest and oil access roads in the Yasuní Biosphere Reserve of Amazonian Ecuador. We collected 95 anurans representing 10 species from 160 bromeliads in 32 trees. We used generalized linear mixed models to assess the effects of disturbance and habitat factors on the occupancy and abundance of anurans collected. Bromeliads in forest along oil roads had a lower occupancy and abundance of anurans than those in undisturbed forest, a somewhat unexpected result due to the intactness and quality of forest adjacent to the roads. Recorded habitat variables had no relationship with occupancy or abundance of anurans, and did not differ significantly between treatments. Our findings reveal that even the minimal footprint of natural resource extraction operations, primarily roads, in rainforest environments can have significant negative impacts on the unique upper canopy anuran community. Based on these results, we recommend that natural resource development treat rainforest habitat as an offshore system where roads are not used, employ industry best practice guidelines, and current access roads be protected from colonization and further deforestation.

Oil Road Effects on the Anuran Community of a High Canopy Tank Bromeliad (Aechmea zebrina) in the Upper Amazon Basin, Ecuador

PubMed Central

McCracken, Shawn F.; Forstner, Michael R. J.

2014-01-01

Tropical forest canopies are among the most species-rich terrestrial habitats on earth and one of the remaining relatively unexplored biotic frontiers. Epiphytic bromeliads provide microhabitat for a high diversity of organisms in tropical forest canopies and are considered a keystone resource. A number of amphibians inhabit these phytotelmata, yet their ecological role and status in forest canopies remains unknown. For this study, anurans were collected from an upper canopy tank bromeliad (Aechmea zebrina) at ∼20–45 m (x¯ = 33 m) above the forest floor. Bromeliads were sampled from trees located near trails in undisturbed primary rainforest and oil access roads in the Yasuní Biosphere Reserve of Amazonian Ecuador. We collected 95 anurans representing 10 species from 160 bromeliads in 32 trees. We used generalized linear mixed models to assess the effects of disturbance and habitat factors on the occupancy and abundance of anurans collected. Bromeliads in forest along oil roads had a lower occupancy and abundance of anurans than those in undisturbed forest, a somewhat unexpected result due to the intactness and quality of forest adjacent to the roads. Recorded habitat variables had no relationship with occupancy or abundance of anurans, and did not differ significantly between treatments. Our findings reveal that even the minimal footprint of natural resource extraction operations, primarily roads, in rainforest environments can have significant negative impacts on the unique upper canopy anuran community. Based on these results, we recommend that natural resource development treat rainforest habitat as an offshore system where roads are not used, employ industry best practice guidelines, and current access roads be protected from colonization and further deforestation. PMID:24416414

Influence on soil properties of prescribed burning under mature red pine.

Treesearch

1977-01-01

Prescribed fires in mature red pine stands reduced shrub competition and the organic layer thickness. The fires reduced nutrient in the forest floor, increased them in the mineral soil, but had no effect on overstory growth.

Vegetation dynamics in Bishrampur collieries of northern Chhattisgarh, India: eco-restoration and management perspectives.

PubMed

Kumar, A; Jhariya, M K; Yadav, D K; Banerjee, A

2017-08-01

Phytosociological study in and around reclaimed coal mine site is an essential requirement for judging restoration impact on a disturbed site. Various studies have been aimed towards assessing the impact of different restoration practices on coal mine wastelands. Plantation scheme in a scientific way is the most suitable approach in this context. During the present investigation, an effort have been made to assess the vegetation dynamics through structure, composition, diversity, and forest floor biomass analysis in and around Bishrampur collieries, Sarguja division, northern Chhattisgarh, India. We have tried to develop strategies for eco-restoration and habitat management of the concerned study sites. Four sites were randomly selected in different directions of the study area. We classified the vegetation community of the study sites into various strata on the basis of height. Two hundred forty quadrats were laid down in various directions of the study area to quantify vegetation under different strata. During our investigation, we found eight different tree species representing four families in the different study sites. The density of the various tree species ranged between 40 and 160 individuals ha -1 . The density of sapling, seedling, shrub, and herb ranged between 740 and 1620; 2000 and 6000; 1200 and 2000; and 484,000 and 612,000 individuals ha -1 , respectively, in different directions. The diversity indices of the tree reflected highest Shannon index value of 1.91. Simpsons index ranged between 0.28 and 0.50, species richness ranged between 0.27 and 0.61, equitability up to 1.44, and Beta diversity ranged between 2.00 and 4.00. Total forest floor biomass ranged between 4.20 and 5.65 t/ha among the study sites. Highest forest floor biomass occurred in the south direction and lowest at east direction. Total forest floor biomass declined by 6.19% in west, 13.10% in north, and 25.66% in east direction, respectively. The mining activities resulted significant damage to natural vegetation and its dynamics. The study indicated that Acacia mangium, Cassia siamea, and Dalbergia sissoo can be recommended for effective eco-restoration of the concerned sites due to cosmopolitan distribution, high regeneration potential, as well as existence in the form of various girth classes with stable population structure.

Charcoal in organic horizon and surface mineral soil in a boreal forest postfire chronosequence of Western Quebec: stocks, depth distribution, chemical properties and a synthesis of related studies

NASA Astrophysics Data System (ADS)

Preston, Caroline M.; Simard, Martin; Bergeron, Yves; Bernard, Guy M.; Wasylishen, Roderick E.

2017-11-01

Wildfires are a major driver of carbon stocks and ecosystem development in Canadian boreal forests, but there is little information on amounts and properties of the charcoal produced. Using data and samples available from a previous study, we determined amounts, depth distribution and chemical properties of visually-determined charcoal (> 2 mm) in a boreal chronosequence in the Abitibi region of Quebec, Canada. Sites ranged from 24 to 2355 years since fire (ysf) and originated from low- and high-severity soil burns (> 5 cm or < 5 cm organic horizon unburned, respectively). Two or three pits were sampled at 1-cm depth intervals from 20 jack pine (Pinus banksiana) sites (one low severity and 19 high severity) and 31 black spruce (Picea mariana) sites (12 low severity and 19 high severity). Site-level charcoal stocks ranged from 50 to 5527 kg ha-1 with high within-site variability and lower stocks for the oldest sites. Depth distributions typically peaked around the organic-mineral interface, but some low-severity sites also had charcoal layers within the organic horizon. Means from 30 samples were 569 mg g-1 total C, 4.1 mg g-1 total N and 140 C/N (molar), with total C and C/N showing a trend of decline with time since fire, and total N showing an increase. Solid-state 13C CPMAS NMR spectra of nine samples showed high variability among the younger samples, but a trend to higher aromaticity for the older ones. A literature survey focusing on boreal forests similarly showed highly variable stocks and chemical properties of charcoal in organic horizon and upper mineral soil, with reduction of variance and lower stocks after several hundred years. This initial variation was also consistent with reports of highly variable temperatures and duration of charring in wildfires. Adding reports available for char production, and considering that most studies of char stocks and production are limited to the organic horizon (forest floor), suggests that initial production of charred material from boreal wildfires might be around 5-10 tonnes ha-1.

Comparison of methods to control floor contamination in an animal research facility.

PubMed

Allen, Kenneth P; Csida, Tarrant; Leming, Jeaninne; Murray, Kathleen; Gauld, Stephen B; Thulin, Joseph

2012-10-01

The authors evaluated the effectiveness of adhesive mats, contamination control flooring, and shoe covers in decreasing the presence of microbial agents on animal holding room floors and footwear. Swab samples taken from animal holding room floors after the use of each product were compared with samples taken from rooms after no products were used. Swab samples were also taken from the heels and soles of the footwear of animal care staff before and after use of each product. The use of contamination control flooring or shoe covers significantly reduced the amount of organic material (as indicated by ATP levels measured by a luminometer) present on floors. Bacterial and ATP contamination of footwear was significantly lower after the use of shoe covers than after the use of adhesive mats or contamination control flooring, and the use of shoe covers led to a greater decrease in contamination before and after use than did use of either of the other two products. Although shoe covers were superior to both adhesive mats and contamination control flooring for decreasing contamination of animal room floors and footwear, facilities must take into account the contamination control standards required, the cost of the product, and the labor and time associated with product use when deciding which contamination control practices to implement.

Spatial heterogeneity of radiocesium in the soil of a broadleaved deciduous forest: the marked role of stemflow

NASA Astrophysics Data System (ADS)

Levia, Delphis; Imamura, Naohiro; Toriyama, Jumpei; Kobayashi, Masahiro; Nanko, Kazuki

2017-04-01

This project amplifies our understanding of the transport of Cs-137 via stemflow in a konara oak forest by examining the spatial distribution of Cs-137 in the soil in both proximal (near-trunk) and distal ( > 1 m form tree trunk) stem areas. We report the Cs-137 concentrations and stocks for twenty-four soil samples harvested from the proximal and distal stem areas around individual trees in a radioactively contaminated konara oak forest in east-central Honshu, Japan. Preferential flowpaths of stemflow on the tree trunk and its point of infiltration into the forest floor was observed by conducting a dye tracer experiment. Experimental results showed that Cs-137 concentrations and stocks were higher in the soils of the proximal stem area as compared to the distal stem area when they corresponded with the preferential flowpaths of stemflow. Moreover, there was a significant relationship between the canopy projection area of individual trees and average soil Cs-137 concentrations and stocks, despite some canopy overlap among even trees. Our findings demonstrate that the spatial patterning of Cs-137 concentrations and stocks in the soil of the proximal stem area are governed (at least partially) by the preferential flowpaths of stemflow along the tree trunk. [Note: This presentation is currently under peer-review for journal publication.

Effects of Litter Manipulation on Litter Decomposition in a Successional Gradients of Tropical Forests in Southern China

PubMed Central

Chen, Hao; Gurmesa, Geshere A.; Liu, Lei; Zhang, Tao; Fu, Shenglei; Liu, Zhanfeng; Dong, Shaofeng; Ma, Chuan; Mo, Jiangming

2014-01-01

Global changes such as increasing CO2, rising temperature, and land-use change are likely to drive shifts in litter inputs to forest floors, but the effects of such changes on litter decomposition remain largely unknown. We initiated a litter manipulation experiment to test the response of litter decomposition to litter removal/addition in three successional forests in southern China, namely masson pine forest (MPF), mixed coniferous and broadleaved forest (MF) and monsoon evergreen broadleaved forest (MEBF). Results showed that litter removal decreased litter decomposition rates by 27%, 10% and 8% and litter addition increased litter decomposition rates by 55%, 36% and 14% in MEBF, MF and MPF, respectively. The magnitudes of changes in litter decomposition were more significant in MEBF forest and less significant in MF, but not significant in MPF. Our results suggest that change in litter quantity can affect litter decomposition, and this impact may become stronger with forest succession in tropical forest ecosystem. PMID:24901698

Geological sampling data and benthic biota classification: Buzzards Bay and Vineyard Sound, Massachusetts

USGS Publications Warehouse

Ackerman, Seth D.; Pappal, Adrienne L.; Huntley, Emily C.; Blackwood, Dann S.; Schwab, William C.

2015-01-01

Sea-floor sample collection is an important component of a statewide cooperative mapping effort between the U.S. Geological Survey (USGS) and the Massachusetts Office of Coastal Zone Management (CZM). Sediment grab samples, bottom photographs, and video transects were collected within Vineyard Sound and Buzzards Bay in 2010 aboard the research vesselConnecticut. This report contains sample data and related information, including analyses of surficial-sediment grab samples, locations and images of sea-floor photography, survey lines along which sea-floor video was collected, and a classification of benthic biota observed in sea-floor photographs and based on the Coastal and Marine Ecological Classification Standard (CMECS). These sample data and analyses information are used to verify interpretations of geophysical data and are an essential part of geologic maps of the sea floor. These data also provide a valuable inventory of benthic habitat and resources. Geographic information system (GIS) data, maps, and interpretations, produced through the USGS and CZM mapping cooperative, are intended to aid efforts to manage coastal and marine resources and to provide baseline information for research focused on coastal evolution and environmental change.

Bacterial Flux by Net Precipitation from the Phyllosphere to the Forest Floor.

NASA Astrophysics Data System (ADS)

Pound, P.; Van Stan, J. T., II; Moore, L. D.; Bittar, T.

2016-12-01

Transport pathways of microbes between ecosystem spheres (atmosphere, phyllosphere, and pedosphere) represent major fluxes in nutrient cycles and have the potential to significantly affect microbial ecological processes. We quantified a previously unexamined microbial flux from the phyllosphere to the pedosphere during rainfall and found it to be substantial. Net rainfall bacterial fluxes for throughfall and stemflow were quantified using flow cytometry and a quantitative Polymerase Chain Reaction (qPCR) assay for a Quercus virginiana (Mill., southern live oak) forest with heavy epiphyte cover of Tillandsia usneoides (L., Spanish moss) and Pleopeltis polypodiodes (L., resurrection fern) in coastal Georgia (Southeast USA). Total net precipitation flux of bacteria was 15 quadrillion cells year-1 ha-1, which (assuming a bacterial cell mass of 1 pg) is approximately 15 kg of bacterial biomass supply per year. Stemflow generation was low in this stand (rarely exceeded 10 L storm-1) yet still delivered half the annual net precipitation flux due to high bacterial concentration. The role of this previously unquantified bacterial flux in the forest floor has also been under studied, yet it may be significant by contributing functional community members (if living) or labile lysates (if dead).

Components of ecosystem evaporation in a temperate coniferous rainforest, with canopy transpiration scaled using sapwood density.

PubMed

Barbour, M M; Hunt, J E; Walcroft, A S; Rogers, G N D; McSeveny, T M; Whitehead, D

2005-02-01

Here we develop and test a method to scale sap velocity measurements from individual trees to canopy transpiration (E(c)) in a low-productivity, old-growth rainforest dominated by the conifer Dacrydium cupressinum. Further, E(c) as a component of the ecosystem water balance is quantified in relation to forest floor evaporation rates and measurements of ecosystem evaporation using eddy covariance (E(eco)) in conditions when the canopy was dry and partly wet. Thermal dissipation probes were used to measure sap velocity of individual trees, and scaled to transpiration at the canopy level by dividing trees into classes based on sapwood density and canopy position (sheltered or exposed). When compared with ecosystem eddy covariance measurements, E(c) accounted for 51% of E(eco) on dry days, and 22% of E(eco) on wet days. Low transpiration rates, and significant contributions to E(eco) from wet canopy evaporation and understorey transpiration (35%) and forest floor evaporation (25%), were attributable to the unique characteristics of the forest: in particular, high rainfall, low leaf area index, low stomatal conductance and low productivity associated with severe nutrient limitation.

Export of Dissolved Organic Carbon following Prescribed Fire on Forested Watersheds: Implications for Watershed Management for Drinking Water Supply

NASA Astrophysics Data System (ADS)

Zhang, W.; Olivares, C. I.; Uzun, H.; Erdem, C. U.; Trettin, C.; Liu, Y.; Robinson, E. R.; Karanfil, T.; Chow, A. T.

2016-12-01

Detrital material in forest watersheds is the major terrestrial source of dissolved organic matter (DOM) and disinfection byproduct (DBP) precursors in surface source waters, but it is also the fuel for forest fires. Prescribed fire, as a fuel reduction technique is intended to reduce the amount of forest detritus, and therefore the risk of wildfire. Accordingly, periodic prescribed fire can reduce the accumulation of detritus on forest floor and the amount of DOM export after forest treatments. To evaluate the effects of prescribed fire on water quality, we conducted a controlled study on a paired first-order watershed system that includes a 160 ha treatment watershed (WS77) and 200 ha control watershed (WS80) on the Santee Experimental Forest, near Charleston South Carolina. WS77 has been used for prescribed fire research since the 1960's, the current experimental burn occurred on April, 2016. WS80 has not been managed or burned for at least 55 years. Gauging stations were equipped with in-situ TOC sensors and flow-proportional water samplers for monitoring temporal trends on water quality. Water samples taken from the first runoff event from both watersheds including rising limb, peak discharge, and falling limb were used for detailed chemical characterizations including DOC and nutrient concentrations, coagulation efficiency, and DBP formation such as trihalomethanes (THMs) and halocacetic acids (HAAs) from chlorination as well as N-nitrosodimethylamine (NDMA) from chlorination, and chemical formula assignment on DOM using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS) before and after chlorination and chloramination. Preliminary FT-ICR-MS data shows that DOM chemical compositions are different between raw samples collected from WS77 and WS80. Chlorination resulted in a shift toward lower molecular mass compared to the raw materials. While chloramination did not cause a drastic mass shift, such a treatment also produced DOM moieties that are significantly different from the raw material. Based on our understanding, this watershed-scale study is the first field-scale study to evaluate the effects of prescribed fire on treatability of drinking water supplies.

The impact of traditional fire management on soil carbon and nitrogen pools in a montane forest, southern Ethiopia

Treesearch

Dong-Gill Kim; Habitamu Taddese; Abrham Belay; Randy Kolka

2016-01-01

We conducted studies to assess the impact of traditional fire management on soil organic carbon and total nitrogen pools. We compared organic carbon and total nitrogen pools in forest floor and mineral soil (0–100-cm depth) in three areas burned by local communities (B) with adjacent unburned areas (UB) (three paired sites; 1, 5 and 9 years since fire; hereafter B1-UB...

RECOMMENDATIONS FOR SAMPLING OF TANK 18 IN F TANK FARM

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

Shine, G.

2009-12-14

Representative sampling is required for characterization of the residual floor material in Tank 18 prior to operational closure. Tank 18 is an 85-foot diameter, 34-foot high carbon steel tank with nominal operating volume of 1,300,000 gallons. It is a Type IV tank, and has been in service storing radioactive materials since 1959. Recent mechanical cleaning of the tank removed all mounds of material. Anticipating a low level of solids in the residual material, Huff and Thaxton [2009] developed a plan to sample the material during the final clean-up process while it would still be resident in sufficient quantities to supportmore » analytical determinations in four quadrants of the tank. Execution of the plan produced fewer solids than expected to support analytical determinations in all four quadrants. Huff and Thaxton [2009] then restructured the plan to characterize the residual floor material separately in the North and the South regions: two 'hemispheres.' This document provides sampling recommendations to complete the characterization of the residual material on the tank bottom following the guidance in Huff and Thaxton [2009] to split the tank floor into a North and a South hemisphere. The number of samples is determined from a modification of the formula previously published in Edwards [2001] and the sample characterization data for previous sampling of Tank 18 described by Oji [2009]. The uncertainty is quantified by an upper 95% confidence limit (UCL95%) on each analyte's mean concentration in Tank 18. The procedure computes the uncertainty in analyte concentration as a function of the number of samples, and the final number of samples is determined when the reduction in the uncertainty from an additional sample no longer has a practical impact on results. The characterization of the full suite of analytes in the North hemisphere is currently supported by a single Mantis rover sample obtained from a compact region near the center riser. A floor scrape sample was obtained from a compact region near the northeast riser and has been analyzed for a shortened list of key analytes. Since the unused portion of the floor scrape sample material is archived and available in sufficient quantity, additional analyses need to be performed to complete results for the full suite of constituents. The characterization of the full suite of analytes in the South hemisphere is currently supported by a single Mantis rover sample; there have been no floor scrape samples previously taken from the South hemisphere. The criterion to determine the number of additional samples was based on the practical reduction in the uncertainty when a new sample is added. This was achieved when five additional samples are obtained. In addition, two archived samples will be used if a contingency such as failing to demonstrate the comparability of the Mantis samples to the floor scrape samples occurs. To complete sampling of the Tank 18 residual floor material, three additional samples should be taken from the North hemisphere and four additional samples should be taken from the South hemisphere. One of the samples from each hemisphere will be archived in case of need. Two of the three additional samples from the North hemisphere and three of the four additional samples from the South hemisphere will be analyzed. Once the results are available, differences between the Mantis and three floor scrape samples (the sample previously obtained near NE riser plus the two additional samples that will be analyzed) results will be evaluated. If there are no statistically significant analyte concentration differences between the Mantis and floor scrape samples, those results will be combined and then UCL95%s will be calculated. If the analyte concentration differences between the Mantis and floor scrape samples are statistically significant, the UCL95%s will be calculated without the Mantis sample results. If further reduction in the upper confidence limits is needed and can be achieved by the addition of the archived samples, they will be analyzed and included in the statistical computations. Initially, the analyte concentrations in the residual material on the floor of Tank 18 will be determined separately in the North and the South hemispheres. However, if final sampling results show that differences between the North and South samples are consistent within sampling variation, then the final computations can be based on consolidating all sample results from the tank floor. Recommended locations may be subject to physical tank access and sampling constraints for the additional samples. The recommendations have been discussed in Section 4 and are based on partitioning the Tank 18 floor into an inner and an outer ring and six 60{sup o} sectors depicted in Figure 1. The location of the border between the inner and outer rings is based on dividing the residual material into two approximately equal volumes.« less

4. Photographic copy of the original construction drawing, 1927, by ...

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

4. Photographic copy of the original construction drawing, 1927, by Missouri State Highway Department. Stress diagrams, floor framing plans, and details of trusses - Doxie Creek Bridge, Spanning Doxie Creek at State Route 5, Forest Green, Chariton County, MO

The impact of four decades of annual nitrogen addition on dissolved organic matter in a boreal forest soil

NASA Astrophysics Data System (ADS)

Rappe-George, M. O.; Gärdenäs, A. I.; Kleja, D. B.

2012-09-01

Addition of mineral nitrogen (N) can alter the concentration and quality of dissolved organic matter (DOM) in forest soils. The aim of this study was to assess the effect of long-term mineral N addition on soil solution concentration of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) in the Stråsan experimental forest (Norway spruce) in Central Sweden. N was added yearly at two levels of intensity and duration: the N1 treatment represented a lower intensity, but a longer duration (43 yr) of N addition than the shorter N2 treatment (24 yr). N additions were terminated in the N2 treatment in 1991. The N treatments began in 1967 when the spruce stands were 9 yr old. Soil solution in the forest floor O, and soil mineral B, horizons were sampled during the growing seasons of 1995 and 2009. Tension and non-tension lysimeters were installed in the O horizon (n=6) and tension lysimeters were installed in the underlying B horizon (n=4): soil solution was sampled at two-week intervals. Although tree growth and O horizon carbon (C) and N stock increased in treatments N1 and N2, the concentration of DOC in O horizon leachates was similar in both N treatments and control. This suggests an inhibitory direct effect of N addition on O horizon DOC. Elevated DON and nitrate in O horizon leachates in the ongoing N1 treatment indicated a move towards N saturation. In B-horizon leachates, the N1 treatment approximately doubled leachate concentration of DOC and DON. DON returned to control levels but DOC remained elevated in B-horizon leachates in N2 plots 19 yr after termination of N addition. Increased aromaticity of the sampled DOM in mineral B horizon in both the ongoing and terminated N treatment indicated that old SOM in the mineral soil was a source of the increased DOC.

STATISTICAL ANALYSIS OF TANK 18F FLOOR SAMPLE RESULTS

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

Harris, S.

2010-09-02

Representative sampling has been completed for characterization of the residual material on the floor of Tank 18F as per the statistical sampling plan developed by Shine [1]. Samples from eight locations have been obtained from the tank floor and two of the samples were archived as a contingency. Six samples, referred to in this report as the current scrape samples, have been submitted to and analyzed by SRNL [2]. This report contains the statistical analysis of the floor sample analytical results to determine if further data are needed to reduce uncertainty. Included are comparisons with the prior Mantis samples resultsmore » [3] to determine if they can be pooled with the current scrape samples to estimate the upper 95% confidence limits (UCL{sub 95%}) for concentration. Statistical analysis revealed that the Mantis and current scrape sample results are not compatible. Therefore, the Mantis sample results were not used to support the quantification of analytes in the residual material. Significant spatial variability among the current sample results was not found. Constituent concentrations were similar between the North and South hemispheres as well as between the inner and outer regions of the tank floor. The current scrape sample results from all six samples fall within their 3-sigma limits. In view of the results from numerous statistical tests, the data were pooled from all six current scrape samples. As such, an adequate sample size was provided for quantification of the residual material on the floor of Tank 18F. The uncertainty is quantified in this report by an upper 95% confidence limit (UCL{sub 95%}) on each analyte concentration. The uncertainty in analyte concentration was calculated as a function of the number of samples, the average, and the standard deviation of the analytical results. The UCL{sub 95%} was based entirely on the six current scrape sample results (each averaged across three analytical determinations).« less

STATISTICAL ANALYSIS OF TANK 19F FLOOR SAMPLE RESULTS

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

Harris, S.

2010-09-02

Representative sampling has been completed for characterization of the residual material on the floor of Tank 19F as per the statistical sampling plan developed by Harris and Shine. Samples from eight locations have been obtained from the tank floor and two of the samples were archived as a contingency. Six samples, referred to in this report as the current scrape samples, have been submitted to and analyzed by SRNL. This report contains the statistical analysis of the floor sample analytical results to determine if further data are needed to reduce uncertainty. Included are comparisons with the prior Mantis samples resultsmore » to determine if they can be pooled with the current scrape samples to estimate the upper 95% confidence limits (UCL95%) for concentration. Statistical analysis revealed that the Mantis and current scrape sample results are not compatible. Therefore, the Mantis sample results were not used to support the quantification of analytes in the residual material. Significant spatial variability among the current scrape sample results was not found. Constituent concentrations were similar between the North and South hemispheres as well as between the inner and outer regions of the tank floor. The current scrape sample results from all six samples fall within their 3-sigma limits. In view of the results from numerous statistical tests, the data were pooled from all six current scrape samples. As such, an adequate sample size was provided for quantification of the residual material on the floor of Tank 19F. The uncertainty is quantified in this report by an UCL95% on each analyte concentration. The uncertainty in analyte concentration was calculated as a function of the number of samples, the average, and the standard deviation of the analytical results. The UCL95% was based entirely on the six current scrape sample results (each averaged across three analytical determinations).« less

Transfer of radio-cesium from forest soil to woodchips using fungal activities

NASA Astrophysics Data System (ADS)

Kaneko, Nobuhiro; Huang, Yao; Tanaka, Yoichiro; Fujiwara, Yoshihiro; Sasaki, Michiko; Toda, Hiroto; Takahashi, Terumasa; Kobayashi, Tatsuaki; Harada, Naoki; Nonaka, Masahiro

2014-05-01

Raido-cesium released to terrestrial ecosystems by nuclear accidents is know to accumulate forest soil and organic layer on the soil. Forests in Japan are not exceptions. Practically it is impossible to decontaminate large area of forests. However, there is a strong demand from local people, who has been using secondary forests (Satoyama) around croplands in hilly areas, to decontaminate radio-cesium, because those people used to collect wild mushrooms and edible plants, and there are active cultures of mushrooms using logs and sawdusts. These natural resource uses consist substantial part of their economical activities, Therefore it is needed to decontaminate some selected part of forests in Japan to local economy. Clear cutting and scraping surface soil and organic matter are common methods of decontamination. However the efficiency of decontamination is up to 30% reduction of aerial radiation, and the cost to preserve contaminated debris is not affordable. In this study we used wood chips as a growth media for saprotrophic fungi which are known to accumulate redio-cesium. There are many studies indicated that mushrooms accumulated redio-cesium from forest soil and organic layer. It is not practical to collect mushrooms to decontaminate redio-cesium, because biomass of mushrooms are not enough to collect total contaminants. Mushrooms are only minor part of saprotrophic fungi. Fungal biomass in forest soil is about 1% of dead organic matter on forest floor. Our previous study to observe Cs accumulation to decomposing leaf litter indicated 18% absorption of total soil radio-Cs to litter during one year field incubation (Kaneko et al., 2013), and Cs concentration was proportional to fungal biomass on litter. This result indicated that fungi transferred radio-cesium around newly supplied leaf litter free of contamination. Therefore effective decontamination will be possible if we can provide large amount of growth media for saprotrophic fungi, and the media can be removed from forests with fungal bodies. We covered forest floor using wood chips, and observed Cs accumulation, and found that up to 50% of soil radio-cesium was transferred from soil to wood chips after 6-month of field incubation. Therefore this method is effective to decontaminate forest using ecological process. Kaneko N, Huang Y, Nakamori T, Tanaka Y, Nonaka M. Radio-cesium accumulation during decomposition of leaf litter in a deciduous forest after the Fukushima NPP accident. Geophysical Research Abstracts. 2013;15(EGU2013):7809.

Effects of Late Stages of Emerald Ash Borer (Coleoptera: Buprestidae)-Induced Ash Mortality on Forest Floor Invertebrate Communities

PubMed Central

Herms, Daniel A

2017-01-01

Abstract Emerald ash borer (EAB; Agrilus planipennis Fairmaire) is an invasive wood-borer causing rapid, widespread ash tree mortality, formation of canopy gaps, and accumulation of coarse woody debris (CWD) in forest ecosystems. The objective of this study was to quantify the effects of canopy gaps and ash CWD on forest floor invertebrate communities during late stages of EAB-induced ash mortality, when the effects of gaps are predicted to be smallest and effects of CWD are predicted to be greatest, according to the model proposed by Perry and Herms 2016a. A 2-year study was conducted in forest stands that had experienced nearly 100% ash mortality in southeastern Michigan, USA, near where EAB first established in North America. In contrast to patterns documented during early stages of the EAB invasion, effects of gaps were minimal during late stages of ash mortality, but invertebrate communities were affected by accumulation and decomposition of CWD. Invertebrate activity-abundance, evenness, and diversity were highest near minimally decayed logs (decay class 1), but diverse taxon-specific responses to CWD affected community composition. Soil moisture class emerged as an important factor structuring invertebrate communities, often mediating the strength and direction of their responses to CWD and stages of decomposition. The results of this study were consistent with the predictions that the effects of CWD on invertebrate communities would be greater than those of canopy gaps during late stages of EAB-induced ash mortality. This research contributes to understanding of the cascading and long-term ecological impacts of invasive species on native forest ecosystems.

SPATIAL AGGREGATION IN A FOREST FLOOR INSECT DEPENDS ON SEASONAL CONGREGATION AND SCATTERING EFFECTS OF PREDATORS

EPA Science Inventory

Spatial aggregations arising from gregarious behavior are common in nature and have important implications for population dynamics, community stability, and conservation. However, the translation of aggregation behaviors into emergent properties of populations and communities de...

Characterization of PM 2.5 collected during broadcast and slash-pile prescribed burns of predominately ponderosa pine forests in northern Arizona

NASA Astrophysics Data System (ADS)

Robinson, Marin S.; Zhao, Min; Zack, Lindsay; Brindley, Christine; Portz, Lillian; Quarterman, Matthew; Long, Xiufen; Herckes, Pierre

2011-04-01

Prescribed burning, in combination with mechanical thinning, is a successful method for reducing heavy fuel loads from forest floors and thereby lowering the risk of catastrophic wildfire. However, an undesirable consequence of managed fire is the production of fine particulate matter or PM 2.5 (particles ≤2.5 μm in aerodynamic diameter). Wood-smoke particulate data from 21 prescribed burns are described, including results from broadcast and slash-pile burns. All PM 2.5 samples were collected in situ on day 1 (ignition) or day 2. Samples were analyzed for mass, polycyclic aromatic hydrocarbons (PAHs), inorganic elements, organic carbon (OC), and elemental carbon (EC). Results were characteristic of low-intensity, smoldering fires. PM 2.5 concentrations varied from 523 to 8357 μg m -3 and were higher on day 1. PAH weight percents (19 PAHs) were higher in slash-pile burns (0.21 ± 0.08% OC) than broadcast burns (0.07 ± 0.03% OC). The major elements were K, Cl, S, and Si. OC and EC values averaged 66 ± 7 and 2.8 ± 1.4% PM 2.5, respectively, for all burns studied, in good agreement with literature values for smoldering fires.

Characterization of PM(2.5) collected during broadcast and slash-pile prescribed burns of predominately ponderosa pine forests in northern Arizona.

PubMed

Robinson, Marin S; Zhao, Min; Zack, Lindsay; Brindley, Christine; Portz, Lillian; Quarterman, Matthew; Long, Xiufen; Herckes, Pierre

2011-04-01

Prescribed burning, in combination with mechanical thinning, is a successful method for reducing heavy fuel loads from forest floors and thereby lowering the risk of catastrophic wildfire. However, an undesirable consequence of managed fire is the production of fine particulate matter or PM(2.5) (particles ≤2.5 µm in aerodynamic diameter). Wood-smoke particulate data from 21 prescribed burns are described, including results from broadcast and slash-pile burns. All PM(2.5) samples were collected in situ on day 1 (ignition) or day 2. Samples were analyzed for mass, polycyclic aromatic hydrocarbons (PAHs), inorganic elements, organic carbon (OC), and elemental carbon (EC). Results were characteristic of low intensity, smoldering fires. PM(2.5) concentrations varied from 523 to 8357 µg m(-3) and were higher on day 1. PAH weight percents (19 PAHs) were higher in slash-pile burns (0.21 ± 0.08% OC) than broadcast burns (0.07 ± 0.03% OC). The major elements were K, Cl, S, and Si. OC and EC values averaged 66 ± 7 and 2.8 ± 1.4% PM(2.5), respectively, for all burns studied, in good agreement with literature values for smoldering fires.

Chemical and carbon-13 cross-polarization magic-angle spinning nuclear magnetic resonance characterization of logyard fines from British Columbia.

PubMed

Preston, C M; Forrester, P D

2004-01-01

Phasing out beehive burners and rising costs for landfilling have increased the need to widen options for utilization of the smaller size fractions of woody wastes generated during log handling and sawmilling in British Columbia. We characterized several size classes of logyard fines up to 16 mm sampled from coastal and interior operations. Total C, total N, ash, and condensed tannin concentrations were consistent with properties derived largely from wood, with varying proportions of bark and mixing with mineral soil. Especially for < 3-mm fractions, the latter resulted in high ash contents that would make them unsuitable for fuel. Solid-state 13C cross-polarization magic-angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectra were consistent with the chemical data, with high O-alkyl intensity and similarity to naturally occurring woody forest floor; no samples were high in aromatic or phenolic C. Aqueous extracts of two < 16-mm fines, which accounted for only a small proportion of the total C, were enriched in alkyl C and had low or undetectable tannins. Application to forest sites might cause short-term immobilization of N, but also might include possible longer-term benefits from reduction of N loss after harvesting and restoration of soil organic matter in degraded sites.

Characterization of PM2.5 collected during broadcast and slash-pile prescribed burns of predominately ponderosa pine forests in northern Arizona

PubMed Central

Zhao, Min; Zack, Lindsay; Brindley, Christine; Portz, Lillian; Quarterman, Matthew; Long, Xiufen; Herckes, Pierre

2011-01-01

Prescribed burning, in combination with mechanical thinning, is a successful method for reducing heavy fuel loads from forest floors and thereby lowering the risk of catastrophic wildfire. However, an undesirable consequence of managed fire is the production of fine particulate matter or PM2.5 (particles ≤2.5 µm in aerodynamic diameter). Wood-smoke particulate data from 21 prescribed burns are described, including results from broadcast and slash-pile burns. All PM2.5 samples were collected in situ on day 1 (ignition) or day 2. Samples were analyzed for mass, polycyclic aromatic hydrocarbons (PAHs), inorganic elements, organic carbon (OC), and elemental carbon (EC). Results were characteristic of low intensity, smoldering fires. PM2.5 concentrations varied from 523 to 8357 µg m−3 and were higher on day 1. PAH weight percents (19 PAHs) were higher in slash-pile burns (0.21 ± 0.08% OC) than broadcast burns (0.07 ± 0.03% OC). The major elements were K, Cl, S, and Si. OC and EC values averaged 66 ± 7 and 2.8 ± 1.4% PM2.5, respectively, for all burns studied, in good agreement with literature values for smoldering fires. PMID:21625396

Pine Forest Harvest Leads to Decade-Scale Alterations in Soil Fungal Communities

NASA Astrophysics Data System (ADS)

Boutton, T. W.; Mushinski, R. M.; Gentry, T. J.

2016-12-01

Forestlands provide a multitude of ecosystem services, and sustainable management is crucial to maintaining the benefits of these ecosystems. Intensive organic matter removal (OMR) of logging residues and forest litter during forest harvest may result in long-term alterations to soil properties and processes. Because fungal activity regulates essential biogeochemical processes in forestlands, changes in soil fungal community structure following OMR may translate into altered soil function. Using a replicated field experiment in southern pine forest in eastern Texas, USA, we sampled soil to a depth of 1 m to assess the impact of intensive OMR on soil fungal communities. Soils were collected from replicated (n = 3 ) loblolly pine (Pinus taeda L.) stands subjected to 3 different harvest intensities (i.e., unharvested old growth stands, bole-only harvest stands, and whole-tree harvest + forest floor removal stands) in 1997. Nearly two decades after trees were harvested and replanted, next generation sequencing of the fungal internal transcribed spacer showed the diversity and community structure of the entire fungal community was altered relative to the unharvested stands. The relative abundance of Ascomycetes increased as OMR intensity increased and was positively correlated to concurrent changes in soil pH. The community composition of fungal functional groups (e.g., ecto- and arbuscular mycorrhizal, saprophytic fungi) was also altered by OMR. The most abundant taxa, Russula exhibited significant reductions in response to increasing intensity of OMR. Results of this study illustrate a linkage between anthropogenically-induced aboveground perturbation, edaphic factors, and belowground soil fungal communities of southern pine forests. Also, these results indicate that tree harvesting effects on soil fungal communities can persist for decades post-harvest, with potential implications for soil functional characteristics.

Evaluating the Impacts of Extreme Events on Ecological Processes Through the Lens of an Ice Storm Manipulation Experiment

NASA Astrophysics Data System (ADS)

Campbell, J. L.; Rustad, L.; Driscoll, C. T.; Fahey, T.; Garlick, S.; Groffman, P.; Schaberg, P. G.

2016-12-01

It is increasingly evident that human-induced climate change is altering the prevalence and severity of extreme weather events. Ice storms are an example of a rare and typically localized extreme weather event that is difficult to predict and has impacts that are poorly understood. We used long-term data and a field manipulation experiment to evaluate how ice storms alter the structure, function, and composition of forest ecosystems. Plots established after a major ice storm in the Northeast in 1998 were re-sampled to evaluate longer-term (17 yr) responses of tree health, productivity, and species composition. Results indicate, that despite changes in herbaceous vegetation in the years immediately after the ice storm, the forest canopy recovered, albeit with some changes in composition, most notably a release of American Beech. An ice storm field manipulation experiment was used to evaluate mechanistic understanding of short term ecological responses. Water from a stream was sprayed above the forest canopy when air temperatures were below freezing, which was effective in simulating a natural ice storm. The experimental design consisted of three levels of ice thickness treatment with two replicates per treatment. The plots with the two more severe icing treatments experienced significant damage to the forest canopy, creating gaps. These plots also had large inputs of fine and coarse woody debris to the forest floor. The exposure to light and presence of brush piles in the more heavily damaged plots resulted in warming with increased spatial variability of soil temperature. Preliminary results from the early growing season have shown no significant changes in soil respiration or soil solution losses of nutrients despite significant forest canopy damage. Further monitoring will determine whether these trends continue in the future.

Assessment of Global Mercury Deposition through Litterfall.

PubMed

Wang, Xun; Bao, Zhengduo; Lin, Che-Jen; Yuan, Wei; Feng, Xinbin

2016-08-16

There is a large uncertainty in the estimate of global dry deposition of atmospheric mercury (Hg). Hg deposition through litterfall represents an important input to terrestrial forest ecosystems via cumulative uptake of atmospheric Hg (most Hg(0)) to foliage. In this study, we estimate the quantity of global Hg deposition through litterfall using statistical modeling (Monte Carlo simulation) of published data sets of litterfall biomass production, tree density, and Hg concentration in litter samples. On the basis of the model results, the global annual Hg deposition through litterfall is estimated to be 1180 ± 710 Mg yr(-1), more than two times greater than the estimate by GEOS-Chem. Spatial distribution of Hg deposition through litterfall suggests that deposition flux decreases spatially from tropical to temperate and boreal regions. Approximately 70% of global Hg(0) dry deposition occurs in the tropical and subtropical regions. A major source of uncertainty in this study is the heterogeneous geospatial distribution of available data. More observational data in regions (Southeast Asia, Africa, and South America) where few data sets exist will greatly improve the accuracy of the current estimate. Given that the quantity of global Hg deposition via litterfall is typically 2-6 times higher than Hg(0) evasion from forest floor, global forest ecosystems represent a strong Hg(0) sink.

Determination of an effective sampling regime to detect salmonella enteritidis in the environment of poultry units.

PubMed

Davies, R H; Wray, C

1996-05-01

A study of the dissemination of Salmonella enteritidis in the poultry breeder industry in the UK showed that the choice of sites for sampling the environment of occupied houses and empty houses which had been disinfected after depopulation had a significant influence on the outcome. Increased isolation rates could be achieved by sampling nest box floors and dust in open slave feed hoppers in occupied poultry houses. Nest box floors were the most sensitive sites for detection of residual environmental contamination in poultry houses where enrofloxacin treatment had been used. Floor sweepings, nest box floors, slave feed hoppers, hydrated wall fabric junctions and high beams and pipes were the most sensitive sample sites in cleansed and disinfected poultry houses. The use of universal disinfectant neutralisers gave good results in laboratory trials but appeared to reduce the isolation rate from field samples.

Carpeting in hospitals: an epidemiological evaluation.

PubMed Central

Anderson, R L; Mackel, D C; Stoler, B S; Mallison, G F

1982-01-01

Epidemiological and microbiological studies were conducted in a hospital room with carpet (CR) and in one with carpet (NCR). Microbiological profiles were determined with specimens obtained from patients admitted to these rooms. Patient records were reviewed to note infection status and other case identities. Eleven-millimeter cylindrical core samples of carpet were obtained, and swab template techniques were used on the bare floor for subsequent enumeration and identification of contaminating microorganisms. In each sampling period, higher microbial counts per square inch (1 in(2) = ca 6.452 cm(2)) were measured for the carpet than for the bare floor. Recovery rates of Enterobacter spp., Klebsiella pneumoniae, and Escherichia coli were higher from carpet samples than from bare floor samples. Typable organisms (such as E. coli, Pseudomonas aeruginosa, K. pneumoniae, and Staphylococcus aureus) obtained from patients were also more frequently recovered from the carpet than from the bare flooring. Patients who stayed in the CR were shown to be colonized with the same types of organisms as those initially recovered from the carpet. However, no statistically significant differences were found in patients in the CR versus NCR in colonization with all typable and nontypable organisms first found on the floor. Disease in patients was found not to be associated with organisms found as contaminants of the carpet or the bare floor. Air above carpeting contained more consistent concentrations of organisms than air above the bare flooring. PMID:7076814

NON-LITTER EFFECTS OF ELEVATED CO2 ON FOREST FLOOR MICROARTHROPOD ABUNDANCES. (R825861)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

11. Photocopy of Sheet 3 of Building Plan R451, (USDA, ...

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

11. Photocopy of Sheet 3 of Building Plan R4-51, (USDA, Forest Service, Intermountain Region, Ogden. File 7300, 'Buildings'.) Construction Details and Floor Framing. - Buffalo Guard Station, Office, U.S. Highway 20/191 at Buffalo River, Island Park, Fremont County, ID

Spatial and temporal small-scale variability of nitrogen mobilization in a forest ecosystem with high N deposition in NW-Germany.

PubMed

Lorz, Carsten; Eissner, Christel; Lethmate, Jürgen; Schneider, Birgit

2010-02-01

For conifer stands in NW-Germany with high DIN load (23-35 kg N ha(-1) a(-1)) and a long history of nitrogen export the risk of N mobilization were investigated. Ammonium is the most mobilized N species, pointing towards either conditions not favoring nitrification or, more likely - under the dominant aerobic conditions - a very high amount of ammonium in the forest floor. Independence of net nitrification and net ammonification from each other indicates the existence of two separate systems. The nitrifying system depends very much on biotic conditions - as a function of energy and moisture - and seems not to be directly related to N deposition. In contrast, for the ammonification system (Oe horizon) a correlation with the sum of ammonium deposition three months prior to sampling was found. However, the role of disturbance, i.e. nitrogen export, during the last centuries and the role of recovery of the N balance during the last 150 years is still not clear. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Nitrogen deposition and soil carbon sequestration: enzymes, experiments, and model estimates (Invited)

NASA Astrophysics Data System (ADS)

Goodale, C. L.; Weiss, M.; Tonitto, C.; Stone, M.

2010-12-01

Atmospheric nitrogen has long been expected to increase forest carbon sequestration, by means of enhanced productivity and litter production. More recently, N deposition has received attention for its potential for inducing soil C sequestration by suppressing microbial decomposition. Here, we present a range of measurements and model projections of the effects of N additions on soil C dynamics in forest soils of the northeastern U.S. A review of field-scale measurements of soil C stocks suggests modest enhancements of soil C storage in long-term N addition studies. Measurements of forest floor material from six long-term N addition studies showed that N additions suppressed microbial biomass and oxidative enzyme activity across sites. Additional analyses on soils from two of these sites are exploring the interactive effects of temperature and N addition on the activity of a range of extracellular enzymes used for decomposition of a range of organic matter. Incubations of forest floor material from four of these sites showed inhibition of heterotrophic respiration by an average of 28% during the first week of incubation, although this inhibition disappeared after 2 to 11 months. Nitrogen additions had no significant effect on DOC loss or on the partitioning of soil C into light or heavy (mineral-associated) organic matter. Last, we have adapted a new model of soil organic matter decomposition for the PnET-CN model to assess the long-term impact of suppressed decomposition on C sequestration in various soil C pools.

Herbivore-mediated material fluxes in a northern deciduous forest under elevated carbon dioxide and ozone concentrations.

PubMed

Meehan, Timothy D; Couture, John J; Bennett, Alison E; Lindroth, Richard L

2014-10-01

Anthropogenic changes in atmospheric carbon dioxide (CO2 ) and ozone (O3 ) are known to alter tree physiology and growth, but the cascading effects on herbivore communities and herbivore-mediated nutrient cycling are poorly understood. We sampled herbivore frass, herbivore-mediated greenfall, and leaf-litter deposition in temperate forest stands under elevated CO2 (c. 560 ppm) and O3 (c. 1.5× ambient), analyzed substrate chemical composition, and compared the quality and quantity of fluxes under multiple atmospheric treatments. Leaf-chewing herbivores fluxed 6.2 g m(-2)  yr(-1) of frass and greenfall from the canopy to the forest floor, with a carbon : nitrogen (C : N) ratio 32% lower than that of leaf litter. Herbivore fluxes of dry matter, C, condensed tannins, and N increased under elevated CO2 (35, 32, 63 and 39%, respectively), while fluxes of N decreased (18%) under elevated O3 . Herbivore-mediated dry matter inputs scaled across atmospheric treatments as a constant proportion of leaf-litter inputs. Increased fluxes under elevated CO2 were consistent with increased herbivore consumption and abundance, and with increased plant growth and soil respiration, previously reported for this experimental site. Results suggest that insect herbivory will reinforce other factors, such as photosynthetic rate and fine-root production, impacting C sequestration by forests in future environments. © 2014 The Authors New Phytologist © 2014 New Phytologist Trust.

15. Photocopy of Sheet 1 of Building Plan R41A, (USDA, ...

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

15. Photocopy of Sheet 1 of Building Plan R4-1A, (USDA, Forest Service, Intermountain Region, Ogden. File 7300, 'Buildings'.) FRONT ELEVATION AND FLOOR PLAN - Buffalo Guard Station, Residence, U.S. Highway 20/191 at Buffalo River, Island Park, Fremont County, ID

10. Photocopy of Sheet 1 of Building Plan R453 (USDA, ...

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

10. Photocopy of Sheet 1 of Building Plan R4-53 (USDA, Forest Service, Intermountain Region, Ogden. File 7300, 'Buildings'.) FRONT AND SIDE ELEVATIONS AND FLOOR PLAN - Buffalo Guard Station, Residence, U.S. Highway 20/191 at Buffalo River, Island Park, Fremont County, ID

Snowy backgrounds enhance the absorption of visible light in forest canopies

NASA Astrophysics Data System (ADS)

Pinty, B.; Widlowski, J.-L.; Verstraete, M. M.; Andredakis, I.; Arino, O.; Clerici, M.; Kaminski, T.; Taberner, M.

2011-03-01

The fraction of radiation absorbed in the canopy depends on the amount and angular distribution of the solar irradiance reaching the top of the canopy as well as the fraction of this irradiance that is transmitted through the canopy gaps and reflected back to the vegetation by the background. This contribution shows that the presence of snow on forest floors enhances the fraction of absorbed Photosynthetically Active Radiation (PAR). A global analysis of satellite-derived products reveals that this enhancement affects evergreen and deciduous forests of the boreal zone. This snow-related effect may usefully contribute to the photosynthesis process in evergreen forests especially during spring time when radiation conditions are marginal but other physiological constraints (such as temperature) permit the necessary biochemical functions to take place.

Long-term nitrogen regulation of forest carbon sequestration

NASA Astrophysics Data System (ADS)

Yang, Y.; Luo, Y.

2009-12-01

It is well established that nitrogen (N) limits plant production but unclear how N regulates long-term terrestrial carbon (C) sequestration in response to rising atmospheric C dioxide (CO2)(Luo et al., 2004). Most experimental evidence on C-N interactions is primarily derived from short-term CO2 manipulative studies (e.g. Oren et al., 2001; Reich et al., 2006a), which abruptly increase C inputs into ecosystems and N demand from soil while atmospheric CO2 concentration in the real world is gradually increasing over time (Luo & Reynolds, 1999). It is essential to examine long-term N regulations of C sequestration in natural ecosystems. Here we present results of a synthesis of more than 100 studies on long-term C-N interactions during secondary succession. C significantly accumulates in plant, litter and forest floor in most studies, and in mineral soil in one-third studies during stand development. Substantial increases in C stock are tightly coupled with N accretion. The C: N ratio in plant increases with stand age in most cases, but remains relatively constant in litter, forest floor and mineral soil. Our results suggest that natural ecosystems could have the intrinsic capacity to maintain long-term C sequestration through external N accrual, high N use efficiency, and efficient internal N cycling.

Ecosystem processes and nitrogen export in northern U.S. watersheds.

USGS Publications Warehouse

Stottlemyer, R.

2001-01-01

There is much interest in the relationship of atmospheric nitrogen (N) inputs to ecosystem outputs as an indicator of possible "nitrogen saturation" by human activity. Longer-term, ecosystem-level mass balance studies suggest that the relationship is not clear and that other ecosystem processes may dominate variation in N outputs. We have been studying small, forested watershed ecosystems in five northern watersheds for periods up to 35 years. Here I summarize the research on ecosystem processes and the N budget. During the past 2 decades, average wet-precipitation N inputs ranged from about 0.1 to 6 kg N ha(-1) year(-1) among sites. In general, sites with the lowest N inputs had the highest output-to-input ratios. In the Alaska watersheds, streamwater N output exceeded inputs by 70 to 250%. The ratio of mean monthly headwater nitrate (NO3-) concentration to precipitation NO3- concentration declined with increased precipitation concentration. A series of ecosystem processes have been studied and related to N outputs. The most important appear to be seasonal change in hydrologic flowpath, soil freezing, seasonal forest-floor inorganic N pools resulting from over-winter mineralization beneath the snowpack, spatial variation in watershed forest-floor inorganic N pools, the degree to which snowmelt percolates soils, and gross soil N mineralization rates.

Floors and Toilets: Association of Floors and Sanitation Practices with Fecal Contamination in Peruvian Amazon Peri-Urban Households.

PubMed

Exum, Natalie G; Olórtegui, Maribel Paredes; Yori, Pablo Peñataro; Davis, Meghan F; Heaney, Christopher D; Kosek, Margaret; Schwab, Kellogg J

2016-07-19

Over two billion people worldwide lack access to an improved sanitation facility that adequately retains or treats feces. This results in the potential for fecal material containing enteric pathogens to contaminate the environment, including household floors. This study aimed to assess how floor type and sanitation practices impacted the concentration of fecal contamination on household floors. We sampled 189 floor surfaces within 63 households in a peri-urban community in Iquitos, Peru. All samples were analyzed for colony forming units (CFUs) of E. coli, and households were evaluated for their water, sanitation, and hygiene characteristics. Results of multivariate linear regression indicated that households with improved sanitation and cement floors in the kitchen area had reduced fecal contamination to those with unimproved sanitation and dirt floors (Beta: -1.18 log10 E. coli CFU/900 cm(2); 95% confidence interval [CI]: -1.77, -0.60). Households that did not versus did share their sanitation facility also had less contaminated kitchen floors (Beta: -0.65 log10 E. coli CFU/900 cm(2); 95% CI: -1.15, -0.16). These findings suggest that the sanitation facilities of a home may impact the microbial load found on floors, contributing to the potential for household floors to serve as an indirect route of fecal pathogen transmission to children.

Soil organic carbon dynamics across a nitrogen deposition gradient: application of the PnET-SOM model to northeastern forest ecosystems

NASA Astrophysics Data System (ADS)

Tonitto, C.; Goodale, C. L.; Ollinger, S. V.; Jenkins, J.

2009-12-01

Anthropogenic forcing of the C and N cycles has caused rapid change in atmospheric CO2 and N deposition, with complex and uncertain effects on forest C and N balance. We developed the PnET-SOM model to enhance the model description of carbon and nitrogen coupling. Here we applied PnET-SOM to study changes to ecosystem carbon storage across a nitrogen deposition gradient. We designed the PnET-SOM model to: 1) represent SOM structured around measurable SOM pools, 2) expand simulated soil horizon complexity beyond the 1-box approach to hydrology and SOM structure used in PnET-CN, 3) model humified and mineral associated SOM using parameters derived from C14 field studies, and 4) couple C and N cycles to allow N-limitation of decomposition and plant growth. We explicitly modeled labile, biochemically recalcitrant (humified SOM), and physically-chemically protected (mineral associated SOM) C pools. These SOM pools are modeled in distinct soil horizons including: a forest floor, a mixed organic horizon, an A horizon, and a B horizon. Slow turnover pools of the A and B horizon constitute a significant proportion of SOC; explicitly modeling a deeper soil profile is important for estimating ecosystem SOC storage. In the latest version of PnET-SOM, we described N mineralization-immobilization in the forest floor based on equations derived in the LIDET synthesis study. Validation of the PnET-SOM model was conducted using 1) long-term water flux and nitrate leaching data from the Hubbard Brook LTER, 2) CO2 respiration observations from the Harvard Forest LTER, and 3) C and N stock and flux observations from the Harvard Forest LTER. In this work, we applied the PnET-SOM model to study the effects of an N deposition gradient on SOC dynamics over a 300 year simulation. We represented the effects of N deposition on litter decomposition by varying the exponential decay parameters of the litter layer based on observations from the Harvard Forest N addition experiment. We derived the change in limit value across the N deposition gradient simulated by applying a polynomial fit to limit values observed in the Harvard Forest N addition experimental plots. In PnET-SOM, changes in SOC dynamics under varying N deposition rates are derived from 1) change in litter decomposition rate, which directly affects OM inputs into soil pools, and 2) altered N availability which limits decomposition of OM throughout the soil profile. In our model application, the coarse woody debris pool decreased with increasing N deposition, while the forest floor pools increased. Relative to SOC pools under current N deposition rates at the Harvard Forest (8 gN/m2), deposition at a rate of 20 gN/m2 over a 300 year simulation resulted in a 3.4% increase in the O horizon humified SOC pool, a 2.3% increase in the A horizon humified SOC pool, a 1.3% increase in the A horizon mineral associated SOC pool, and a 0.14% increase in the B horizon mineral associated SOC pool.

Methods to Reduce Forest Residue Volume after Timber Harvesting and Produce Black Carbon.

PubMed

Page-Dumroese, Deborah S; Busse, Matt D; Archuleta, James G; McAvoy, Darren; Roussel, Eric

2017-01-01

Forest restoration often includes thinning to reduce tree density and improve ecosystem processes and function while also reducing the risk of wildfire or insect and disease outbreaks. However, one drawback of these restoration treatments is that slash is often burned in piles that may damage the soil and require further restoration activities. Pile burning is currently used on many forest sites as the preferred method for residue disposal because piles can be burned at various times of the year and are usually more controlled than broadcast burns. In many cases, fire can be beneficial to site conditions and soil properties, but slash piles, with a large concentration of wood, needles, forest floor, and sometimes mineral soil, can cause long-term damage. We describe several alternative methods for reducing nonmerchantable forest residues that will help remove excess woody biomass, minimize detrimental soil impacts, and create charcoal for improving soil organic matter and carbon sequestration.

Role of acid and aluminum-rich media in the growth and nutrition of Pacific Northwest conifers

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

Ryan, P.J.

1983-01-01

Forest soils of coastal Washington and Oregon tend to be very acidic with large accumulations of organic matter. Yet the productivity of forest species on these sites can attain record levels. The effect of acid and aluminum-rich media on the growth and nutrition of Pacific Northwest conifer species was investigated for western hemlock, Douglas-fir, western redcedar, and Sitka spruce. The four different types of growth media utilized were solution cultures, sand cultures, mineral soils, and forest floor organic matter. Hydroponic nutrient solutions and sand cultures were used in experiments designed to differentiate the effect of aluminum ions from the hydrogenmore » ions generated by hydrolysis of Al/sup 3 +/. Relative to agronomic plants, all the conifers were found tolerant of the acid solutions and high levels of aluminum. Species differed in their relative tolerance to H/sup +/ and Al/sup 3/ ions. Western hemlock seedling growth was superior to Douglas-fir in the acidified soils and forest floor media, while Ca(OH)/sub 2/ amendment favored Douglas-fir. The marginal increase in western hemlock growth in N + P treated soils was highest in acidified soils. Western hemlock exhibited an ability to absorb nutrients in the presence of excess solution H/sup +/ ions, maintain growth with low tissue requirements of Ca and Mg, and accumulate high levels of aluminum in its roots and foliage without major adverse effect. These attributes are considered to make western hemlock the most acid and Al-tolerant of the four Pacific Northwest forest species studied. Western redcedar was second in acid tolerance to western hemlock. This species' ability to accumulate Ca minimized Al absorption and H/sup +/ damage to its roots.« less

Short- and long-term effects of fire on carbon in US dry temperate forest systems

USGS Publications Warehouse

Hurteau, Matthew D.; Brooks, Matthew L.

2011-01-01

Forests sequester carbon from the atmosphere, and in so doing can mitigate the effects of climate change. Fire is a natural disturbance process in many forest systems that releases carbon back to the atmosphere. In dry temperate forests, fires historically burned with greater frequency and lower severity than they do today. Frequent fires consumed fuels on the forest floor and maintained open stand structures. Fire suppression has resulted in increased understory fuel loads and tree density; a change in structure that has caused a shift from low- to high-severity fires. More severe fires, resulting in greater tree mortality, have caused a decrease in forest carbon stability. Fire management actions can mitigate the risk of high-severity fires, but these actions often require a trade-off between maximizing carbon stocks and carbon stability. We discuss the effects of fire on forest carbon stocks and recommend that managing forests on the basis of their specific ecologies should be the foremost goal, with carbon sequestration being an ancillary benefit. ?? 2011 by American Institute of Biological Sciences. All rights reserved.

Post Wildfire Changes in Plant Functioning and Vegetation Dynamics: Implications for Water Fluxes in Re-sprouting Forests

NASA Astrophysics Data System (ADS)

Nolan, R. H.; Lane, P. N.; Mitchell, P. J.; Bradstock, R. A.

2011-12-01

Fire induced changes to the vegetation dynamics in temperate forests have been demonstrated to affect evapotranspiration (Et) rates through increases in plant size and density and stand-level transpiration and interception. In many cases these transient changes in forest structure result in substantial declines in stream flow for protracted periods after the disturbance. However to date research has focused on the wetter 'ash' forests of south-eastern Australia which solely regenerate via seedlings, it is unknown what changes in Et may occur in those forests which re-sprout post-fire. We hypothesize that Et fluxes track post-fire changes in sapwood area and leaf area index (L) in re-sprouting temperate forests, increasing as the forest regenerates. Following the 2009 Black Saturday wildfires in Victoria, we monitored Et rates for over a year in both damp and dry re-sprouting forest, incorporating a range of fire severity classes. Components of Et including overstorey transpiration, rainfall interception loss and forest floor Et were measured in conjunction with changes in L, sapwood area and leaf physiology. The monitoring period began one year post-fire with a typical hot, dry summer, at which stage Et rates in burnt forest were similar or less than those in unburnt forest. During the following summer, which was one of the wettest on record, Et increased across all monitoring plots but particularly so in the burnt forest where seedling regeneration resulted in an understorey L nearly twice that of unburnt forest. Forest floor Et was up to 46% higher in burnt forest, and rainfall interception values accounted for approximately 25% of rainfall compared to 15% in unburnt forest. The greatest increase in canopy transpiration rates over this period occurred in those trees subject to a low intensity fire where most of the canopy remained intact but there was also fire-triggered sprouting of new leaves along the trunk and main branches. In these trees rates of sapflow, standardized by sapwood area, were up to 50% greater than in unburnt trees. Measurements of leaf physiology in mature leaves, regenerating canopy leaves and in seedlings indicate higher rates of stomatal conductance in seedlings, and in the early regeneration phase of canopy leaves, which may be driving higher rates of water use per unit leaf area in the early stages of post-fire regeneration. This research indicates that disturbance-induced changes in vegetation dynamics are dependent on fire severity and can alter forest energy and water balances through changes in stand structure (i.e. L) and adjustments in plant functioning via leaf level increases in water use.

10. PERSPECTIVE VIEW OF NORTH (REAR) AND WEST SIDE OF ...

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

10. PERSPECTIVE VIEW OF NORTH (REAR) AND WEST SIDE OF SECOND FLOOR, WEST ROOM SHOWING RELATIONSHIP TO NORTH TERREPLEIN OF NORTHWEST DEMI-BASTION AND STAIRS LEADING TO GUN MOUNT ABOVE MAIN GATE - Fort Washington, Main Gate, Fort Washington Road, Fort Washington Forest, Prince George's County, MD

75 FR 5561 - Information Collection; Disposal of Mineral Materials

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-03

... Ivette Torres, Liaison Specialist, Minerals and Geology Management, Mail Stop 1126, 1601 N. Kent Street... Office of the Director, Minerals and Geology Management, 1601 N. Kent Street[boxh]5th Floor, Forest... and Geology Management Staff at 703-605-4792 to facilitate entry to the building. Individuals who use...

A probabilistic approach to modeling postfire erosion after the 2009 australian brushfires

USDA-ARS?s Scientific Manuscript database

Major concerns after bushfires and wildfires include increased flooding, erosion and debris flows due to loss of the protective forest floor layer, loss of water storage, and creation of water repellent soil conditions. To assist postfire assessment teams in their efforts to evaluate fire effects an...

9. Photocopy of Sheet 1 of Building Plan R451, (USDA, ...

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

9. Photocopy of Sheet 1 of Building Plan R4-51, (USDA, Forest Service, Intermountain Region, Ogden. File 7300, 'Buildings'.) Front, Rear, and Side Elevations and Floor Plan. - Buffalo Guard Station, Office, U.S. Highway 20/191 at Buffalo River, Island Park, Fremont County, ID

4. Photocopy of Sheet 1 of Building Plan R421, (USDA, ...

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

4. Photocopy of Sheet 1 of Building Plan R4-21, (USDA, Forest Service, Intermountain Region, Ogden. File 7300, 'Buildings') FRONT AND SIDE ELEVATIONS, FLOOR AND FOUNDATION PLANS. - Buffalo Guard Station, Garage, U.S. Highway 20/191 at Buffalo River, Island Park, Fremont County, ID

Relating the temporal change observed by AIRSAR to surface and canopy properties of mixed conifer and hardwood forests of northern Michigan

NASA Technical Reports Server (NTRS)

Dobson, M. Craig; Mcdonald, Kyle; Ulaby, Fawwaz T.; Sharik, Terry

1991-01-01

The mixed hardwood and conifer forests of northern Michigan were overflown by a 3-frequency airborne imaging radar in Apr. and Jul. 1990. A set of 10 x 10 km test sites near the University of Michigan Biological Station at Douglas Lake and within the Hiawatha National Forest in the upper peninsula of Michigan contained training stands representing the various forest species typical of forest communities across the ecotone between the coniferous boreal forest and mid-latitude hardwood and coniferous forests. The polarimetric radar data were externally calibrated to allow interdate comparisons. The Apr. flight was prior to bud-break of deciduous species and patchy snowcover was present. The Jul. flights occurred during and 2 days after heavy rain showers, and provide a unique opportunity to examine the differences in radar backscatter attributable to intercepted precipitation. Analyses show that there are significant changes in backscattering between biophysically dissimilar forest stands on any given date and also between dates for a given forest stand. These differences in backscattering can be related to moisture properties of the forest floor and the overlying canopy and also to the quantity and organizational structure of the above-ground biomass.

Nitrogen mineralization and nitrification in a mixed-conifer forest in southern California: controlling factors, fluxes, and nitrogen fertilization response at a high and low nitrogen deposition site

Treesearch

Mark E. Fenn; Mark A. Poth; Joseph D. Terry; Timothy J. Blubaugh

2005-01-01

Net fluxes of nitrogen (N) mineralization and nitrification were measured in situ on a monthly basis for 3 years at a high (HN) and low (LN) N deposition site in the San Bernardino Mountains, California. Mean N mineralization fluxes in the forest floor and top 10 cm of mineral soil were 19.0 and 59.8 kg N·ha–1·year–1 at LN...

Response of birds to thinning young Douglas-fir forests

USGS Publications Warehouse

Hayes, John P.; Weikel, Jennifer M.; Huso, Manuela M. P.; Erickson, Janet L.

2003-01-01

As a result of recent fire history and decades of even-aged forest management, many coniferous forests in western Oregon are composed of young (20-50 yrs), densely stocked Douglas-fir stands. Often these stands are structurally simple - a single canopy layer with one or two overstory tree species - and have a relatively sparse understory. The lack of structural complexity in these stands may limit the availability of key habitat components for several species of vertebrates, including birds. Thinning may increase structural diversity by reducing competition among overstory trees and increasing the amount of sunlight reaching the forest floor, thereby increasing development of understory vegetation. Existing old-growth forests may have developed under lower densities than is typical of contemporary plantations. Thus, thinning also may be a tool for accelerating the development of late-successional forest conditions in some circumstances. In addition to the potential increases in structural and biological diversity, thinning frequently is used to optimize wood fiber production and to generate timber revenue.

The biotransformation of soil biocenosis by micromycetes under introduction of Fagus sylvatica L. to oak-hornbeam forest

NASA Astrophysics Data System (ADS)

Likhanov, Artur; Bilyera, Nataliya; Sedykh, Olena; Melnychuk, Maksym

2017-04-01

Keywords: micromycetes, beech, soil enzymes, illuminance, Penicillium canescens. European beech (Fagus sylvatica L.) is a commercially valuable tree species. As the potential distribution area for beech forest is restricted by Europe, planting of artificial stands is adopted in this region. Beech introduction can alter ecosystem considerably, but the mechanism of this transformation is not clear. We aimed to define abiotic and biotic parameters affecting floor development in beech stands introduced to the oak-hornbeam forest ecosystem ca.50 years ago in Eastern Europe (Ukraine). The daylight illuminace level was similar (2.9-6.5 klx) for both stands. However, grass cover in beech stands did not exceed 0.1-0.5 % even on sites with illuminace level 7.5-8.3 klx. It does not comply with the commonly used suggestion that shading is the main factor causes forest floor absence in the beech stands. We indicated predominantly biotic factors influencing forest floor formation. Thus, particular edaphon represented by micromycetes was able to inhibit plants and microorganisms. We isolated Penicillium canescens strains from soil under beech stands. These fungi utilized beech root exudates and phenol compounds of leaf litter, and produced biologically active substances caused cytostatic and mutagenic effects. They also accelerated (in 2-3.2 times) soil β-glucosidase activity, but had no effect on phosphatase. The biomass of fungi varied under cultivation of Penicillium canescens strains on Czapek medium with the addition of aqueous extracts of beech leaf litter. The biomass of micromycetes increased on 10-15 % at plant phenols concentrations up to 1 mg mL-1. On the contrary, increasing the concentration of phenols up to 4 mg mL-1resulted in a biomass decrease to 40%. The relationship between the concentration of plant phenols and rate of fungal biomass formation indicates that there is probably seasonal regulation of micromycetes activity in the forest biocenosis. The highest biological activity of soil fungi was observed in spring under the optimum phenol level for them. It was found experimentally that the cellulose addition to the Czapek medium at the amount of 100 mg L-1 leads to an increase in the synthesis of substances with a pronounced herbicidal action. Medium- and low polar fungi metabolites (curvularin, griseofulvin, polyacetylen) significantly inhibited root growth of test plants. They provided a cytostatic effect and caused numerous irregularities in cell division (formation of chromosome bridges and micronuclei). Thus, the introduction of Fagus sylvatica L. in Kyiv Polissya leads to the formation of unique environmental conditions in the forest soils. They contributed to the dominance of micromycetes (mainly genus Penicillium) in the soil. Soil fungi transformed leaf litter and inhibited the growth and development of plants of the lower tier by producing exudates. This led to a significant reduction in the biodiversity of the forest biocenosis.

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR FIELD COLLECTION OF INDOOR FLOOR SAMPLES AND POST FIELD SAMPLE HANDLING (UA-F-7.1)

EPA Science Inventory

The purpose of this SOP is to establish a uniform procedure for the collection of indoor floor dust samples in the field. This procedure was followed to ensure consistent data retrieval of dust samples during the Arizona NHEXAS project and the "Border" study. Keywords: field; va...

RECOMMENDATIONS FOR SAMPLING OF TANK 19 IN F TANK FARM

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

Harris, S.; Shine, G.

2009-12-14

Representative sampling is required for characterization of the residual material in Tank 19 prior to operational closure. Tank 19 is a Type IV underground waste storage tank located in the F-Tank Farm. It is a cylindrical-shaped, carbon steel tank with a diameter of 85 feet, a height of 34.25 feet, and a working capacity of 1.3 million gallons. Tank 19 was placed in service in 1961 and initially received a small amount of low heat waste from Tank 17. It then served as an evaporator concentrate (saltcake) receiver from February 1962 to September 1976. Tank 19 also received the spentmore » zeolite ion exchange media from a cesium removal column that once operated in the Northeast riser of the tank to remove cesium from the evaporator overheads. Recent mechanical cleaning of the tank removed all mounds of material. Anticipating a low level of solids in the residual waste, Huff and Thaxton [2009] developed a plan to sample the waste during the final clean-up process while it would still be resident in sufficient quantities to support analytical determinations in four quadrants of the tank. Execution of the plan produced fewer solids than expected to support analytical determinations in all four quadrants. Huff and Thaxton [2009] then restructured the plan to characterize the residual separately in the North and the South regions: two 'hemispheres.' This document provides sampling recommendations to complete the characterization of the residual material on the tank bottom following the guidance in Huff and Thaxton [2009] to split the tank floor into a North and a South hemisphere. The number of samples is determined from a modification of the formula previously published in Edwards [2001] and the sample characterization data for previous sampling of Tank 19 described by Oji [2009]. The uncertainty is quantified by an upper 95% confidence limit (UCL95%) on each analyte's mean concentration in Tank 19. The procedure computes the uncertainty in analyte concentration as a function of the number of samples, and the final number of samples is determined when the reduction in the uncertainty from an additional sample no longer has a practical impact on results. The characterization of the full suite of analytes in the North and South hemispheres is currently supported by a single Mantis rover sample in each hemisphere. A floor scrape sample was obtained from a compact region near the center riser slightly in the South hemisphere and has been analyzed for a shortened list of key analytes. There is not enough additional material from the floor scrape sample material for completing the full suite of constituents. No floor scrape samples have been previously taken from the North hemisphere. The criterion to determine the number of additional samples was based on the practical reduction in the uncertainty when a new sample is added. This was achieved when five additional samples are obtained. In addition, two archived samples will be used if a contingency such as failing to demonstrate the comparability of the Mantis samples to the floor scrape samples occurs. To complete sampling of the Tank 19 residual floor material, four additional samples should be taken from the North hemisphere and four additional samples should be taken from the South hemisphere. One of the samples from each hemisphere will be archived in case of need. Three of the four additional samples from each hemisphere will be analyzed. Once the results are available, differences between the Mantis and three floor scrape sample results will be evaluated. If there are no statistically significant analyte concentration differences between the Mantis and floor scrape samples, those results will be combined and then UCL95%s will be calculated. If the analyte concentration differences between the Mantis and floor scrape samples are statistically significant, the UCL95%s will be calculated without the Mantis sample results. If further reduction in the upper confidence limits is needed and can be achieved by the addition of the archived samples, they will be analyzed and included in the statistical computations. Initially the analyte concentrations in the residual material on the floor of Tank 19 will be determined separately in the North and the South hemispheres. However, if final sampling results show that differences between the North and South samples are consistent within sampling variation, then the final computations can be based on consolidating all sample results from the tank floor. Recommended locations may be subject to physical tank access and sampling constraints for the additional samples. The recommendations have been discussed in Section 4 and are based on partitioning the Tank 19 floor into an inner and an outer ring and six 60{sup o} sectors depicted in Figure 1. The location of the border between the inner and outer rings is based on dividing the residual material into two approximately equal volumes.« less

Comparison of Bi-directional Reflectance Distribution Functions of Black Spruce Forest in Snow and No-snow Seasons in Alaska

NASA Astrophysics Data System (ADS)

Suzuki, R.; Nagai, S.; Nakai, T.; Kim, Y.

2011-12-01

The Bidirectional Reflectance Distribution Function (BRDF) of the forest is an important clue for remote sensing to reveal the forest structure such as Leaf Area Index (LAI) and above-ground biomass. The BRDF is required for the robust development of forest radiative transfer model, which is applied to the forest structure analysis based on satellite data. To acquire in-situ BRDF of the forest, we carried out the field survey of BRDFs at a boreal forest in no-snow season (July 2010) and snow season (March 2011) in Alaska, and compared them. A black spruce forest, a typical boreal evergreen forest in Alaska, located in the Poker Flat Research Range of University of Alaska Fairbanks (65 07'24"N, 147 29'15"W, 210 m MSL) was targeted. Since the forest homogeneously extends about 500 m wide and the terrain is relatively even, this forest site is highly suitable for the validation of the remote sensing measurement. The tree stand density was about 4000 tree/ha, and the highest tree was 6.4 m. The forest floor is covered by the green vegetation such as moss and grass in summer, while the vegetation on the floor is completely covered by snow during winter and early spring. The observations of the BRDF taken place around the noon of July 7 and 8, 2010 (no-snow season) and March 16 and 17, 2011 (snow season) from the top of the tower (17 m) constructed in the forest. We measured the reflected irradiance from the forest by the spectroradiometer (MS-720; EKO Instruments) changing the viewing angle from 20 to 70 degrees and -20 to -70 degrees(off-nadir angle; positive and negative angles mean forward and back scatter angles, respectively) with 5 degrees interval in the principal plane. Irradiances in the orthogonal (cross) plane were also measured in the same manner. The global radiation was simultaneously measured by the other spectroradiometer for the calculation of the reflectance. The BRDF in the principal plane in the no-snow season showed a kind of bowl-shape distribution with its minimum and maximum at approximately 30 and -70 degrees in visible and near-infrared bands, respectively, that is, the forward scatter was generally smaller than the back scatter. By contrast, in the snow season, the back scatter was generally smaller than the forward scatter, that is, the reverse of that in the no-snow season. These results will be used for the development of the forest radiative transfer model aimed to evaluate the forest biodiversity and ecosystem functions.

Sea-floor morphology and sedimentary environments in southern Narragansett Bay, Rhode Island

USGS Publications Warehouse

McMullen, Katherine Y.; Poppe, Lawrence J.; Blackwood, Dann S.; Nardi, Matthew J.; Andring, Matthew A.

2015-09-09

Multibeam echosounder data collected by the National Oceanic and Atmospheric Administration along with sediment samples and still and video photography of the sea floor collected by the U.S. Geological Survey were used to interpret sea-floor features and sedimentary environments in southern Narragansett Bay, Rhode Island, as part of a long-term effort to map the sea floor along the northeastern coast of the United States. Sea-floor features include rocky areas and scour depressions in high-energy environments characterized by erosion or nondeposition, and sand waves and megaripples in environments characterized by coarse-grained bedload transport. Two shipwrecks are also located in the study area. Much of the sea floor is relatively featureless within the resolution of the multibeam data; sedimentary environments in these areas are characterized by processes associated with sorting and reworking. This report releases bathymetric data from the multibeam echosounder, grain-size analyses of sediment samples, and photographs of the sea floor and interpretations of the sea-floor features and sedimentary environments. It provides base maps that can be used for resource management and studies of topics such as benthic ecology, contaminant inventories, and sediment transport.

Carbon stocks across a chronosequence of thinned and unmanaged red pine (Pinus resinosa) stands

USGS Publications Warehouse

Powers, Matthew D.; Kolka, Randall K.; Bradford, John B.; Palik, Brian J.; Fraver, Shawn; Jurgensen, Martin F.

2012-01-01

Forests function as a major global C sink, and forest management strategies that maximize C stocks offer one possible means of mitigating the impacts of increasing anthropogenic CO2 emissions. We studied the effects of thinning, a common management technique in many forest types, on age-related trends in C stocks using a chronosequence of thinned and unmanaged red pine (Pinus resinosa) stands ranging from 9 to 306 years old. Live tree C stocks increased with age to a maximum near the middle of the chronosequence in unmanaged stands, and increased across the entire chronosequence in thinned stands. C in live understory vegetation and C in the mineral soil each declined rapidly with age in young stands but changed relatively little in middle-aged to older stands regardless of management. Forest floor C stocks increased with age in unmanaged stands, but forest floor C decreased with age after the onset of thinning around age 40 in thinned stands. Deadwood C was highly variable, but decreased with age in thinned stands. Total ecosystem C increased with stand age until approaching an asymptote around age 150. The increase in total ecosystem C was paralleled by an age-related increase in total aboveground C, but relatively little change in total belowground C. Thinning had surprisingly little impact on total ecosystem C stocks, but it did modestly alter age-related trends in total ecosystem C allocation between aboveground and belowground pools. In addition to characterizing the subtle differences in C dynamics between thinned and unmanaged stands, these results suggest that C accrual in red pine stands continues well beyond the 60–100 year management rotations typical for this system. Management plans that incorporate longer rotations and thinning in some stands could play an important role in maximizing C stocks in red pine forests while meeting other objectives including timber extraction, biodiversity conservation, restoration, and fuel reduction goals.

One year monitoring of fire-induced effects on dissolved organic matter and nutrient dynamics under different land-use

NASA Astrophysics Data System (ADS)

Potthast, Karin; Meyer, Stefanie; Crecelius, Anna; Schubert, Ulrich; Michalzik, Beate

2016-04-01

It is supposed that the changing climate will promote extreme weather events that in turn will increase drought periods and the abundance of fire events in temperate climate regions such as Central Europe. The impact of fires on the nutrient budgets of ecosystems is highly diverse and seems to depend on the ecosystem type. For example, little is known about fire effects on water-bound organic matter (OM) and nutrient fluxes in temperate managed forest ecosystems. Fires can strongly alter the distribution (forest floor vs. mineral soil), binding forms (organic vs. inorganic) and availability (solubility by water) of OM and associated nutrients. To elucidate the effects and seasonality of low intensity fires on the mobilization of dissolved organic carbon and nutrients, an experimental ground fire was conducted in November 2014 in the Hainich region, Central Germany. In addition, differences in response patterns between two land-use types (pasture and beech forest) were investigated. Lysimeters (n=5 controls/ 5 fire-manipulated) with topsoil monoliths (0-4 cm), rainfall/throughfall samplers, littertraps as well as temperature and moisture sensors were installed on three sites of each land-use type. During the one year of monitoring (Sep14-Dec15) soil solution, rainfall, and throughfall samples were taken biweekly and analyzed for pH, dissolved and particulate organic carbon (DOC, POC) and nitrogen (DN, PN) as well as for nutrients (e.g. K, Ca, Mg, P, S). Compared to the control sites, the ground fire immediately induced a short-run release peak of DOC in both land-use types. Within two weeks these differences were muted in the post-fire period. The effect of fire was land-use specific with annual DOC fluxes of 82 and 45 kg/(ha*a) for forest and pasture sites, respectively. In contrast, nitrogen fluxes responded differently to the fire event. In the forest, a significant increase in DN concentrations was notable five months after the fire, at the beginning of the vegetation period and lasted until November with DN concentrations in June being 4 times higher compared to the control (82 vs. 18 mg DN/L) and being negatively correlated with pH-values (r=-0.51 p<0.001). Annual DN fluxes from fire manipulated forest plots were two times higher compared to control ones (62 vs. 29 kg DN/(ha*a)) whereas only low impact was found at the pasture with 45 and 38 kg DN/(ha*a) for fire-manipulated plots and control, respectively. In general, the results exhibit highly differing response patterns of elements to fire between the two land-use types and with season. Starting in spring higher DN fluxes following fire event at the forest site could be associated with accelerated activity of soil microbes mineralizing released organic substances from burned forest floor and/or from dead roots. This mineralization process resulted in a significant increase in acidity of the soil solution that may affect important ecosystem functions like nutrient cycling and primary production. Hence, high resolution monitoring following a low intensive fire indicated nutrient losses from the forest ecosystem that could be a hazard for managed forests on nutrient poor soils if fire frequency increases with climate change.

Tropical Rain Forest Structure, Tree Growth and Dynamics along a 2700-m Elevational Transect in Costa Rica

PubMed Central

Clark, David B.; Hurtado, Johanna; Saatchi, Sassan S.

2015-01-01

Rapid biological changes are expected to occur on tropical elevational gradients as species migrate upslope or go extinct in the face of global warming. We established a series of 9 1-ha plots in old-growth tropical rainforest in Costa Rica along a 2700 m relief elevational gradient to carry out long-term monitoring of tropical rain forest structure, dynamics and tree growth. Within each plot we mapped, identified, and annually measured diameter for all woody individuals with stem diameters >10 cm for periods of 3-10 years. Wood species diversity peaked at 400-600 m and decreased substantially at higher elevations. Basal area and stem number varied by less than two-fold, with the exception of the 2800 m cloud forest summit, where basal area and stem number were approximately double that of lower sites. Canopy gaps extending to the forest floor accounted for <3% of microsites at all elevations. Height of highest crowns and the coefficient of variation of crown height both decreased with increasing elevation. Rates of turnover of individuals and of stand basal area decreased with elevation, but rates of diameter growth and stand basal area showed no simple relation to elevation. We discuss issues encountered in the design and implementation of this network of plots, including biased sampling, missing key meteorological and biomass data, and strategies for improving species-level research. Taking full advantage of the major research potential of tropical forest elevational transects will require sustaining and extending ground based studies, incorporation of new remotely-sensed data and data-acquisition platforms, and new funding models to support decadal research on these rapidly-changing systems. PMID:25856163

Nitrogen retention in contrasting temperate forests exposed to high nitrogen deposition

NASA Astrophysics Data System (ADS)

Staelens, J.; Adriaenssens, S.; Wuyts, K.; Verheyen, K.; Boeckx, P. F.

2011-12-01

A better understanding of factors affecting nitrogen (N) retention is needed to assess the impact of changing anthropogenic N emissions and climatic conditions on N cycling and N loss by terrestrial ecosystems. Retention of N has been demonstrated for a wide range of forests, including ecosystems exposed to chronically enhanced N deposition, but it is still unclear which factors determine this N retention capacity. Therefore, we examined the possible effects of forest type on N retention using stable N isotopes. The study was carried out in adjacent equal-aged deciduous (pedunculate oak (Quercus robur L.)) and coniferous (Scots pine (Pinus sylvestris L.)) stands with a similar stand history and growing on a well-drained sandy soil in a region with enhanced N deposition (Belgium). The N input-output budgets and gross soil N transformation rates differed significantly between the two stands. The forest floor was exposed to a high inorganic N input from atmospheric deposition, which was nearly twice as high in the pine stand (33 ± 2 kg N ha-1 yr-1; mean ± standard error) as in the oak stand (18 ± 1 kg N ha-1 yr-1). The N input was reflected in the soil solution under the rooting zone, but the mean nitrate concentration was eight times higher under pine (19 ± 5 mg N L-1) than under oak (2.3 ± 0.9 mg N L-1). Gross N dynamics in the mineral topsoil were determined by in situ 15N labelling of undisturbed soil cores combined with numerical data analysis. Gross N mineralization was two times faster in the oak soil while nitrate production was two times faster in the pine soil, indicating a dominant effect of vegetation cover on soil N cycling. The higher gross nitrification, particularly due to oxidation of organic N, in the pine soil compared to the oak soil, combined with negligible nitrate immobilization, was in line with the higher nitrate leaching under the pine forest. On a larger spatial and temporal scale, the fate of dissolved inorganic N within these forests was studied by spraying three pulses of 15N onto the forest floor during the growing season, either as ammonium or as nitrate. Four months and one year after the first application, 15N recovery was determined in the organic and mineral soil layers, fine tree roots, soil water percolate, ferns, and tree foliage. As hypothesized, N retention in the forest floor and mineral soil horizons was lower in the pine stand compared to oak, while N retention was lower for nitrate than for ammonium in both stands. The differences in 15N retention confirm that tree species affect the N balance of ecosystems under high anthropogenic N inputs and agree with the findings on gross soil N dynamics and N input-output budgets. Overall, the research underlines the importance of considering the interaction between tree species and carbon and N turnover when assessing the response of forest ecosystems to global change scenarios.

U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--STANDARD OPERATING PROCEDURE FOR FIELD COLLECTION AND POST-FIELD SAMPLE HANDLING OF INDOOR FLOOR DUST SAMPLES (UA-F-7.1)

EPA Science Inventory

The purpose of this SOP is to establish a uniform procedure for the collection of indoor floor dust samples in the field. This procedure was followed to ensure consistent data retrieval of dust samples during the Arizona NHEXAS project and the Border study. Keywords: field; vacu...

Early understory biomass response to organic matter removal and soil compaction

Treesearch

Felix Jr. Ponder

2008-01-01

In the Missouri Ozarks, 6 and 8 years after treatment, understory biomass differences between bole only harvesting (BO) and whole-tree plus forest floor harvesting were not different; neither were there understory biomass differences between no compaction and severe compaction. Separation of the biomass into broad species categories (trees, shrubs, annuals, perennials...

Using prescribed fire to regenerate Table Mountain pine in the Southern Appalachian Mountains

Treesearch

Patrick H. Brose; Thomas A. Waldrop

2000-01-01

Stand-replacing prescribed fires are recommended to regenerate stands of Table Mountain pine (Pinus pungens) in the southern Appalachian Mountains because the species has serotinous cones and its seedlings require abundant sunlight and a thin forest floor. A 350-hectare prescribed fire in northeastern Georgia provided an opportunity to observe...

Effect of Harvest Residue Management on Tree Productivity and Carbon Pools during Early Stand Development in a Loblolly Pine Plantation

Treesearch

Chris A. Maier; Kurt H. Johnsen; Phillip Dougherty; Daniel McInnis; Pete Anderson; Steve Patterson

2012-01-01

Soil incorporation of postharvest forest floor or logging residues during site preparation increased mineral soil carbon (C) and nitrogen (N) concentration and had a differential effect on early stand growth in a clonal loblolly pine (Pinus taeda L.) plantation. Incorporating 25 Mg ha

Postfire rehabilitation treatments: are we learning what works?

Treesearch

P. R. Robichaud; R. E. Brown

2005-01-01

Major concerns after wildfires are the increased erosion and flooding potential due to loss of the protective forest floor layer, loss of water storage, and the creation of water repellent soil conditions. Treatments to mitigate postfire erosion and runoff are commonly applied on highly erodible areas; however the effectiveness of these treatments has had limited...

36 CFR 1192.153 - Doors, steps and thresholds.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Doors, steps and thresholds... Over-the-Road Buses and Systems § 1192.153 Doors, steps and thresholds. (a) Floor surfaces on aisles, step treads and areas where wheelchair and mobility aid users are to be accommodated shall be slip...

Wolfhounds and Polar Bears in Siberia: America’s Military Intervention, 1918-1920

DTIC Science & Technology

1986-01-01

including sable, sea otter, otter, beaver, mink, muskrat, squirrel, fox, skunk, woodchuck, marmot , badger, glutton, and rabbit. Vast forests provided wood for...venti- lated, heated, and lighted. A kitchen was found on the end of each floor in the barracks. Latrines drained into open cesspools. Wood burning

76 FR 64318 - Multilayered Wood Flooring From the People's Republic of China: Final Determination of Sales at...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-18

... Parity (``Petitioner''), Style Limited, Shanghai Lizhong Wood Products Co., Ltd/The Lizhong Wood Industry... submitted case briefs on August 4, 2011. On August 9, 2011, Petitioner, Style Limited, Lumber Liquidators... Environment and Natural Resources, Forest Management Bureau (``FMB'')'s 2009 price data for lauan plywood...

Nitrogen fertilization stimulates germination of dormant pin cherry seed

Treesearch

L.R. Auchmoody

1979-01-01

Nitrogen fertilizers triggered germination of dormant Prunus pensylvanica L. seed naturally buried in the forest floor of 60-year-old Allegheny hardwood stands. Neither triple superphosphate nor muriate of potash applied with urea increased germination over that which occurred with urea alone. Rates as low as 56 kg/ha N from urea and calcium...

Fire effects on ponderosa pine soils and their management implications

Treesearch

W.W. Covington; S.S. Sackett

1990-01-01

Fire in southwestern ponderosa pine induces changes in soil properties including decreasing the amount of nutrients stored in fuels (forest floor, woody litter, and understory vegetation) increasing the amount of nutrients on the soil surface (the "ashbed effect"), and increasing the inorganic nitrogen and moisture content in the mineral soil. Soil...

Handbook for inventorying surface fuels and biomass in the Interior West

Treesearch

James K. Brown; Rick D. Oberheu; Cameron M. Johnston

1982-01-01

Presents comprehensive procedures for inventorying weight per unit area of living and dead surface vegetation, to facilitate estimation of biomass and appraisal of fuels. Provides instructions for conducting fieldwork and calculating estimates of downed woody material, forest floor litter and duff, herbaceous vegetation, shrubs, and small conifers. Procedures produce...

Teacher's Manual for Outdoor Studies: Geneva Sixth Grades.

ERIC Educational Resources Information Center

Mitchinson, Don F.

Written for teachers who lead their 6th grade students on a 3-day field experience program at the Rogers Environmental Education Center in Sherburne, New York, this manual provides objectives, materials, and procedures for activities which help students learn about the natural environment--pond life, trees, ecology of the forest floor, stream…

Anthropogenic N Deposition Slows Decay by Favoring Bacterial Metabolism: Insights from Metagenomic Analyses

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

Freedman, Zachary B.; Upchurch, Rima A.; Zak, Donald R.

Litter decomposition is an enzymatically-complex process that is mediated by a diverse assemblage of saprophytic microorganisms. It is a globally important biogeochemical process that can be suppressed by anthropogenic N deposition. In a northern hardwood forest ecosystem located in Michigan, USA, 20 years of experimentally increased atmospheric N deposition has reduced forest floor decay and increased soil C storage. Here, we paired extracellular enzyme assays with shotgun metagenomics to assess if anthropogenic N deposition has altered the functional potential of microbial communities inhabiting decaying forest floor. Experimental N deposition significantly reduced the activity of extracellular enzymes mediating plant cell wallmore » decay, which occurred concurrently with changes in the relative abundance of metagenomic functional gene pathways mediating the metabolism of carbohydrates, aromatic compounds, as well as microbial respiration. Moreover, experimental N deposition increased the relative abundance of 50 of the 60 gene pathways, the majority of which were associated with saprotrophic bacteria. Conversely, the relative abundance and composition of fungal genes mediating the metabolism of plant litter was not affected by experimental N deposition. Future rates of atmospheric N deposition have favored saprotrophic soil bacteria, whereas the metabolic potential of saprotrophic fungi appears resilient to this agent of environmental change. Results presented here provide evidence that changes in the functional capacity of saprotrophic soil microorganisms mediate how anthropogenic N deposition increases C storage in soil.« less

Anthropogenic N Deposition Slows Decay by Favoring Bacterial Metabolism: Insights from Metagenomic Analyses

DOE PAGES

Freedman, Zachary B.; Upchurch, Rima A.; Zak, Donald R.; ...

2016-03-02

Litter decomposition is an enzymatically-complex process that is mediated by a diverse assemblage of saprophytic microorganisms. It is a globally important biogeochemical process that can be suppressed by anthropogenic N deposition. In a northern hardwood forest ecosystem located in Michigan, USA, 20 years of experimentally increased atmospheric N deposition has reduced forest floor decay and increased soil C storage. Here, we paired extracellular enzyme assays with shotgun metagenomics to assess if anthropogenic N deposition has altered the functional potential of microbial communities inhabiting decaying forest floor. Experimental N deposition significantly reduced the activity of extracellular enzymes mediating plant cell wallmore » decay, which occurred concurrently with changes in the relative abundance of metagenomic functional gene pathways mediating the metabolism of carbohydrates, aromatic compounds, as well as microbial respiration. Moreover, experimental N deposition increased the relative abundance of 50 of the 60 gene pathways, the majority of which were associated with saprotrophic bacteria. Conversely, the relative abundance and composition of fungal genes mediating the metabolism of plant litter was not affected by experimental N deposition. Future rates of atmospheric N deposition have favored saprotrophic soil bacteria, whereas the metabolic potential of saprotrophic fungi appears resilient to this agent of environmental change. Results presented here provide evidence that changes in the functional capacity of saprotrophic soil microorganisms mediate how anthropogenic N deposition increases C storage in soil.« less

Contribution of fine tree roots to the silicon cycle in a temperate forest ecosystem developed on three soil types

NASA Astrophysics Data System (ADS)

Turpault, Marie-Pierre; Calvaruso, Christophe; Kirchen, Gil; Redon, Paul-Olivier; Cochet, Carine

2018-04-01

The role of forest vegetation in the silicon (Si) cycle has been widely examined. However, to date, little is known about the specific role of fine roots. The main objective of our study was to assess the influence of fine roots on the Si cycle in a temperate forest in north-eastern France. Silicon pools and fluxes in vegetal solid and solution phases were quantified within each ecosystem compartment, i.e. in the atmosphere, above-ground and below-ground tree tissues, forest floor and different soil layers, on three plots, each with different soil types, i.e. Dystric Cambisol (DC), Eutric Cambisol (EC) and Rendzic Leptosol (RL). In this study, we took advantage of a natural soil gradient, from shallow calcic soil to deep moderately acidic soil, with similar climates, atmospheric depositions, species compositions and management. Soil solutions were measured monthly for 4 years to study the seasonal dynamics of Si fluxes. A budget of dissolved Si (DSi) was also determined for the forest floor and soil layers. Our study highlighted the major role of fine roots in the Si cycle in forest ecosystems for all soil types. Due to the abundance of fine roots mainly in the superficial soil layers, their high Si concentration (equivalent to that of leaves and 2 orders higher than that of coarse roots) and their rapid turnover rate (approximately 1 year), the mean annual Si fluxes in fine roots in the three plots were 68 and 110 kg ha-1 yr-1 for the RL and the DC, respectively. The turnover rates of fine roots and leaves were approximately 71 and 28 % of the total Si taken up by trees each year, demonstrating the importance of biological recycling in the Si cycle in forests. Less than 1 % of the Si taken up by trees each year accumulated in the perennial tissues. This study also demonstrated the influence of soil type on the concentration of Si in the annual tissues and therefore on the Si fluxes in forests. The concentrations of Si in leaves and fine roots were approximately 1.5-2.0 times higher in the Si-rich DC compared to the Si-poor RL. In terms of the DSi budget, DSi production was large in the three plots in the forest floor (9.9 to 12.7 kg ha-1 yr-1), as well as in the superficial soil layer (5.3 to 14.5 kg ha-1 yr-1), and decreased with soil depth. An immobilization of DSi was even observed at 90 cm depth in plot DC (-1.7 kg ha-1 yr-1). The amount of Si leached from the soil profile was relatively low compared to the annual uptake by trees (13 % in plot DC to 29 % in plot RL). The monthly measurements demonstrated that the seasonal dynamics of the DSi budget were mainly linked to biological activity. Notably, the peak of dissolved Si production in the superficial soil layer occurred during winter and probably resulted from fine-root decomposition. Our study reveals that biological processes, particularly those involving fine roots, play a predominant role in the Si cycle in temperate forest ecosystems, while the geochemical processes appear to be limited.

Patterns of NPP, GPP, respiration, and NEP during boreal forest succession

USGS Publications Warehouse

Goulden, M.L.; Mcmillan, A.M.S.; Winston, G.C.; Rocha, A.V.; Manies, K.L.; Harden, J.W.; Bond-Lamberty, B. P.

2011-01-01

We combined year-round eddy covariance with biometry and biomass harvests along a chronosequence of boreal forest stands that were 1, 6, 15, 23, 40, 74, and 154 years old to understand how ecosystem production and carbon stocks change during recovery from stand-replacing crown fire. Live biomass (Clive) was low in the 1 and 6 year old stands, and increased following a logistic pattern to high levels in the 74 and 154year old stands. Carbon stocks in the forest floor (Cforest floor) and coarse woody debris (CCWD) were comparatively high in the 1year old stand, reduced in the 6 through 40year old stands, and highest in the 74 and 154year old stands. Total net primary production (TNPP) was reduced in the 1 and 6year old stands, highest in the 23 through 74year old stands and somewhat reduced in the 154year old stand. The NPP decline at the 154year old stand was related to increased autotrophic respiration rather than decreased gross primary production (GPP). Net ecosystem production (NEP), calculated by integrated eddy covariance, indicated the 1 and 6 year old stands were losing carbon, the 15year old stand was gaining a small amount of carbon, the 23 and 74year old stands were gaining considerable carbon, and the 40 and 154year old stands were gaining modest amounts of carbon. The recovery from fire was rapid; a linear fit through the NEP observations at the 6 and 15year old stands indicated the transition from carbon source to sink occurred within 11-12 years. The NEP decline at the 154year old stand appears related to increased losses from Clive by tree mortality and possibly from Cforest floor by decomposition. Our findings support the idea that NPP, carbon production efficiency (NPP/GPP), NEP, and carbon storage efficiency (NEP/TNPP) all decrease in old boreal stands. ?? 2010 Blackwell Publishing Ltd.

Formaldehyde and TVOC emission behavior of laminate flooring by structure of laminate flooring and heating condition.

PubMed

An, Jae-Yoon; Kim, Sumin; Kim, Hyun-Joong

2011-03-15

Formaldehyde was measured with a desiccator, a 20 L chamber and the FLEC method. The formaldehyde emission rate from laminate was the highest at 32 °C using the desiccator, which then decreased with time. The formaldehyde emission using the 20 L small chamber and FLEC showed a similar tendency. There was a strong correlation between the formaldehyde and total volatile organic compounds (TVOCs) with both types of floorings using the two different methods. The formaldehyde emission rate and TVOC results were higher when tested using the FLEC method than with the 20 L small chamber method. The emission rate was affected by the joint edge length in laminate flooring. Toluene, ethylbenzene and xylene were the main VOCs emitted from laminate flooring, and there were more unidentified VOCs emitted than identified VOCs. The samples heated with a floor heating system emitted more formaldehyde than those heated using an air circulation system due to the temperature difference between the bottom panel and flooring. The TVOC emission level of the samples was higher when an air circulation system was used than when a floor heating system was used due to the high ventilation rate. Copyright © 2010 Elsevier B.V. All rights reserved.

CTEPP STANDARD OPERATING PROCEDURE FOR COLLECTION OF FLOOR DUST SAMPLES FOR PERSISTENT ORGANIC POLLUTANTS (SOP-2.19)

EPA Science Inventory

This SOP describes the method for collecting a floor dust sample from carpet. Dust samples will be collected in the room that the child uses most at home and/or at day care using a High Volume Small Surface Sampler (HVS3). In addition, participants will also be asked to donate a ...

Similar below-ground carbon cycling dynamics but contrasting modes of nitrogen cycling between arbuscular mycorrhizal and ectomycorrhizal forests.

PubMed

Lin, Guigang; McCormack, M Luke; Ma, Chengen; Guo, Dali

2017-02-01

Compared with ectomycorrhizal (ECM) forests, arbuscular mycorrhizal (AM) forests are hypothesized to have higher carbon (C) cycling rates and a more open nitrogen (N) cycle. To test this hypothesis, we synthesized 645 observations, including 22 variables related to below-ground C and N dynamics from 100 sites, where AM and ECM forests co-occurred at the same site. Leaf litter quality was lower in ECM than in AM trees, leading to greater forest floor C stocks in ECM forests. By contrast, AM forests had significantly higher mineral soil C concentrations, and this result was strongly mediated by plant traits and climate. No significant differences were found between AM and ECM forests in C fluxes and labile C concentrations. Furthermore, inorganic N concentrations, net N mineralization and nitrification rates were all higher in AM than in ECM forests, indicating 'mineral' N economy in AM but 'organic' N economy in ECM trees. AM and ECM forests show systematic differences in mineral vs organic N cycling, and thus mycorrhizal type may be useful in predicting how different tree species respond to multiple environmental change factors. By contrast, mycorrhizal type alone cannot reliably predict below-ground C dynamics without considering plant traits and climate. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Do Forest Age and Soil Depth Affect Carbon and Nitrogen Adsorption in Mineral Horizons?

NASA Astrophysics Data System (ADS)

Spina, P. G.; Lovett, G. M.; Fuss, C. B.; Goodale, C. L.; Lang, A.; Fahey, T.

2015-12-01

Mineral soils retain large amounts of organic matter through sorption on the surfaces of mineral soils, the largest pools of carbon (C) and nitrogen (N) in the forests of the northeastern U.S. In addition to determining organic matter storage, adsorption and desorption processes are important controllers of runoff chemistry. We are studying adsorption dynamics of mineral soils collected from a chronosequence of hardwood forest sites in the White Mountains, NH to determine how soils vary in their DOM adsorption capacities as a function of effective C and N saturation. We hypothesize that forest age determines proximity to saturation because young forests may need to mine soil organic matter (SOM) in mineral soils to obtain nitrogen to meet growth demands, while the soils of older forests have had time to reaccumulate SOM, eventually reaching C and N saturation. Consequently, we expect adsorption capacities to first increase with forest age in young forests, as the trees mine C and N from mineral surfaces. They will then decrease with forest age in older forests as mining slows and C and N begin to re-accumulate. Batch experiments were conducted with mineral soil samples and dilutions of forest floor leachate. However, preliminary results from a mature forest site (about 100 years old), which we predicted to be a low point of C and N saturation from decades of mining, contradict expectations. Dissolved organic carbon (DOC) adsorption in its shallow mineral soil layers (0-3 cm below E or A horizons) are lower than younger sites ranging from 20 to about 40 years old. In addition to forest age, soil depths also affect N retention dynamics in forest soils. We hypothesized that deeper mineral soils might have greater adsorption capacities due to the fact that they are exposed to less DOC and DON leaching from organic layers and therefore less saturated. Results from the same mature forest site confirm this. Soils from 3-10 cm depth have more potential to adsorb DOC and DON than soils from 0-3 cm depth. For example, at 80 mg/L DOC, the >3-10 layer adsorbed 11.37 mg total N (TN)/g dry soil whereas the 0-3 layer adsorbed 2.13 mg TN/g dry soil. This project will also consider the effects of soil texture, soil C and N content, and Al and Fe oxide and hydroxide content.

Archeointensity study on baked clay samples taken from the reconstructed ancient kiln: implication for validity of the Tsunakawa-Shaw paleointensity method

NASA Astrophysics Data System (ADS)

Yamamoto, Yuhji; Torii, Masayuki; Natsuhara, Nobuyoshi

2015-05-01

In 1972, a reconstruction experiment of a kiln had been done to reproduce an excavated kiln of the seventh century in Japan. Baked clay samples were taken from the floor surface and -20 cm level, and they have been stored after determinations of the paleomagnetic directions by partial alternating field demagnetizations. We recently applied the Tsunakawa-Shaw method to the samples to assess how reliable archeointensity results are obtained from the samples. A suite of the rock magnetic experiments and the scanning electron microscope observations elucidate that dominant magnetic carriers of the floor surface samples are Ti-poor titanomagnetite grains in approximately 10 nm size with single-domain and/or super-paramagnetic states, whereas contributions of multi-domain grains seem to be relatively large for the -20-cm level samples. From the floor surface samples, six out of the eight successful results were obtained and they give an average of 47.3 μT with a standard deviation of 2.2 μT. This is fairly consistent with the in situ geomagnetic field of 46.4 μT at the time of the reconstruction. They are obtained with a built-in anisotropy correction using anhysteretic remanent magnetization and without any cooling rate corrections. In contrast, only one out of four was successful from the -20-cm level samples. It yields an archeointensity of 31.6 μT, which is inconsistent with the in situ geomagnetic field. Considering from the in situ temperature record during the firing of the kiln and the unblocking temperature spectra of the samples, the floor surface samples acquired full thermoremanent magnetizations (TRMs) as their natural remanent magnetizations whereas the -20-cm level samples only acquired partial TRMs, and these differences probably cause the difference in the archeointensity results between the two sample groups. For archeointensity researches, baked clay samples from a kiln floor are considered to be ideal materials.

Methods to Reduce Forest Residue Volume after Timber Harvesting and Produce Black Carbon

PubMed Central

Busse, Matt D.; Archuleta, James G.; McAvoy, Darren; Roussel, Eric

2017-01-01

Forest restoration often includes thinning to reduce tree density and improve ecosystem processes and function while also reducing the risk of wildfire or insect and disease outbreaks. However, one drawback of these restoration treatments is that slash is often burned in piles that may damage the soil and require further restoration activities. Pile burning is currently used on many forest sites as the preferred method for residue disposal because piles can be burned at various times of the year and are usually more controlled than broadcast burns. In many cases, fire can be beneficial to site conditions and soil properties, but slash piles, with a large concentration of wood, needles, forest floor, and sometimes mineral soil, can cause long-term damage. We describe several alternative methods for reducing nonmerchantable forest residues that will help remove excess woody biomass, minimize detrimental soil impacts, and create charcoal for improving soil organic matter and carbon sequestration. PMID:28377830

Forest fire in the central Himalaya: climate and recovery of trees

NASA Astrophysics Data System (ADS)

Sharma, Subrat; Rikhari, H. C.

A forest fire event is influenced by climatic conditions and is supported by accumulation of fuel on forest floor. After forest fire, photosynthetically active solar radiation was reduced due to accumulation of ash and dust particles in atmosphere. Post-fire impacts on Quercus leucotrichophora, Rhododendron arboreum and Lyonia ovalifolia in a broadleaf forest were analysed after a wild fire. Bark depth damage was greatest for L. ovalifolia and least for Q. leucotrichophora. Regeneration of saplings was observed for all the tree species through sprouting. Epicormic recovery was observed for the trees of all the species. Young trees of Q. leucotrichophora (<40 cm circumference at breast height) were susceptible to fire as evident by the lack of sprouting. Under-canopy tree species have a high potential for recovery as evident by greater length and diameter of shoots and numbers of buds and leaves per shoot than canopy species. Leaf area, leaf moisture and specific leaf area were greater in the deciduous species, with few exceptions, than in evergreen species.

Carbon and nitrogen distribution in oak-hickory forests distributed along a productivity gradient

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

Reber, R.T.; Kaczmarek, D.J.; Pope, P.E.

1993-12-31

Biomass, carbon and nitrogen pools were determined for oak-hickory forests of varying productivity. Little information of this type is available for the central hardwood region. Six oak-hickory dominated forests were chosen to represent a range in potential site productivity as influenced by soil type, amount of recyclable nutrients and available water. Biomass, carbon and nitrogen storage were determined for the following components: above ground standing biomass, fine root biomass, forest floor organic layers and litterfall. As site sequestered at each site was dependent more on the amount of living biomass at each site Litterfall, to some extent, increased with increasingmore » site productivity. As potential site productivity decreased, total fine root biomass increased. The data suggest that as site quality decreased fine root production and turnover may become as important in nutrient cycling as annual litterfall.« less

Deposition of aerially applied BT in an oak forest and its prediction with the FSCBG model

USGS Publications Warehouse

Anderson, Dean E.; Miller, David R.; Wang, Yansen; Yendol, William G.; Mierzejewski, Karl; McManus, Michael L.

1992-01-01

Data are provided from 17 single-swath aerial spray trials that were conducted over a fully leafed, 16-m tall, mixed oak forest. The distribution of cross-swath spray deposits was sampled at the top of the canopy and below the canopy. Micrometeorological conditions were measured above and within the canopy during the spray trials. The USDA Forest Service FSCBG (Forest Service-Cramer-Barry-Grim) model was run to predict the target sampler catch for each trial using forest stand, airplane-application-equipment configuration, and micrometeorological conditions as inputs. Observations showed an average cross-swath deposition of 100 IU cm−2 with large run-to-run variability in deposition patterns, magnitudes, and drift. Eleven percent of the spray material that reached the top of the canopy penetrated through the tree canopy to the forest floor.The FSCBG predictions of the ensemble-averaged deposition were within 17% of the measured deposition at the canopy top and within 8% on the ground beneath the canopy. Run-to-run deposit predictions by FSCBG were considerably less variable than the measured deposits. Individual run predictions were much less accurate than the ensemble-averaged predictions as demonstrated by an average root-mean-square-error (rmse) of 27.9 IU CM−2 at the top of the canopy. Comparisons of the differences between predicted and observed deposits indicated that the model accuracy was sensitive to atmospheric stability conditions. In neutral and stable conditions, a regular pattern of error was indicated by overprediction of the canopy-top deposit at distances from 0 to 20 m downwind from the flight line and underprediction of the deposit both farther downwind than 20 m and upwind of the flight line. In unstable conditions the model generally underpredicted the deposit downwind from the flight line, but showed no regular pattern of error.

Is Nitrogen Deposition Altering the Nitrogen Status of Northeastern Forests?

NASA Astrophysics Data System (ADS)

Aber, J. D.; Goodale, C. L.; Ollinger, S. V.; Smith, M.; Magill, A. H.; Martin, M. E.; Hallett, R. A.; Stoddard, J. L.; Participants, N.

2002-05-01

The nitrogen saturation hypothesis suggests that foliar and soil N concentration, nitrification rate, and nitrate leaching loss should all increase in response to increased N deposition. We tested this hypothesis with a major new synthesis of foliar (362 plots), soil (251 plots), and surface water (354 lakes and streams) chemistry from the northeastern U.S. Nitrogen deposition decreases across the Northeast from ~ 10-12 kg ha-1 yr-1 in the Mid-Atlantic region to ~ 4 kg ha-1 yr-1 in northern Maine. Foliar chemistry (%N and lignin:N ratio) of red spruce and sugar maple correlated more strongly with elevation than with N deposition, although these factors covary. Forest floor C:N ratio decreased with N deposition for both conifers and hardwoods although correlations were not strong (R2 < 0.20). Regardless of forest type or soil horizon, percent nitrification (as a fraction of N mineralization) increased as soil C:N decreased below ~25, and increased weakly with N deposition in hardwood stands. Across the Northeast, surface water seasonal nitrate concentrations and N export during the mid- to late-1990s increased with N deposition (R2 = 0.30-0.56), with two important patterns emerging: 1) nitrate rarely exceeded 1 μ mol/L in watersheds receiving <8-10 kg ha-1 yr-1; and 2) high nitrate concentrations occurred only in lakes and streams receiving relatively high N inputs. This pattern resembles that for European forests. Factors such as species composition, forest history, climate, and hydrology may affect foliar, soil, and stream chemistry at different spatial and temporal scales. Foliar and soil chemistry may be more strongly influenced by local heterogeneity, whereas surface water samples integrate over much larger areas. Using surface waters as the most comprehensive indicator of N saturation, it appears that N deposition is altering the N status of forests in the northeastern U.S.

Forest type effects on the retention of radiocesium in organic layers of forest ecosystems affected by the Fukushima nuclear accident

PubMed Central

Koarashi, Jun; Atarashi-Andoh, Mariko; Matsunaga, Takeshi; Sanada, Yukihisa

2016-01-01

The Fukushima Daiichi nuclear power plant disaster caused serious radiocesium (137Cs) contamination of forest ecosystems over a wide area. Forest-floor organic layers play a key role in controlling the overall bioavailability of 137Cs in forest ecosystems; however, there is still an insufficient understanding of how forest types influence the retention capability of 137Cs in organic layers in Japanese forest ecosystems. Here we conducted plot-scale investigations on the retention of 137Cs in organic layers at two contrasting forest sites in Fukushima. In a deciduous broad-leaved forest, approximately 80% of the deposited 137Cs migrated to mineral soil located below the organic layers within two years after the accident, with an ecological half-life of approximately one year. Conversely, in an evergreen coniferous forest, more than half of the deposited 137Cs remained in the organic layers, with an ecological half-life of 2.1 years. The observed retention behavior can be well explained by the tree phenology and accumulation of 137Cs associated with litter materials with different degrees of degradation in the organic layers. Spatial and temporal patterns of gamma-ray dose rates depended on the retention capability. Our results demonstrate that enhanced radiation risks last longer in evergreen coniferous forests than in deciduous broad-leaved forests. PMID:27974832

Forest type effects on the retention of radiocesium in organic layers of forest ecosystems affected by the Fukushima nuclear accident

NASA Astrophysics Data System (ADS)

Koarashi, Jun; Atarashi-Andoh, Mariko; Matsunaga, Takeshi; Sanada, Yukihisa

2016-12-01

The Fukushima Daiichi nuclear power plant disaster caused serious radiocesium (137Cs) contamination of forest ecosystems over a wide area. Forest-floor organic layers play a key role in controlling the overall bioavailability of 137Cs in forest ecosystems; however, there is still an insufficient understanding of how forest types influence the retention capability of 137Cs in organic layers in Japanese forest ecosystems. Here we conducted plot-scale investigations on the retention of 137Cs in organic layers at two contrasting forest sites in Fukushima. In a deciduous broad-leaved forest, approximately 80% of the deposited 137Cs migrated to mineral soil located below the organic layers within two years after the accident, with an ecological half-life of approximately one year. Conversely, in an evergreen coniferous forest, more than half of the deposited 137Cs remained in the organic layers, with an ecological half-life of 2.1 years. The observed retention behavior can be well explained by the tree phenology and accumulation of 137Cs associated with litter materials with different degrees of degradation in the organic layers. Spatial and temporal patterns of gamma-ray dose rates depended on the retention capability. Our results demonstrate that enhanced radiation risks last longer in evergreen coniferous forests than in deciduous broad-leaved forests.

Sampling and inactivation of wet disseminated spores from flooring materials using commercially available robotic vacuum cleaners.

PubMed

Thompson, Katy-Anne; Paton, Susan; Pottage, Thomas; Bennett, Allan

2018-05-09

Four commercially available robotic vacuum cleaners were assessed for sampling efficiency of wet disseminated Bacillus atrophaeus spores on carpet, Polyvinyl Chloride (PVC) and laminate flooring. Furthermore, their operability was evaluated and decontamination efficiency of one robot was assessed using a sodium hypochlorite solution. In an environmental chamber, robots self-navigated around 4 m 2 of flooring containing a single contaminated 0.25 m 2 tile (ca. 10 4 spores per cm 2 ). Contamination levels at pre-determined locations were assessed by macrofoam swabs (PVC and laminate) or water soluble tape (carpet), before and after sampling. Robots were dismantled post-sampling and spore recoveries assessed. Aerosol contamination was also measured during sampling. Robot sampling efficiencies were variable, however, robots recovered most spores from laminate (up to 17.1%), then PVC, and lastly carpet. All robots spread contamination from the 'hotspot' (all robots spread < 0.6% of the contamination to other areas) and became surface contaminated. Spores were detected at low levels during air sampling (<5.6 spores l -1 ). Liquid decontamination inactivated 99.1% of spores from PVC. Robotic vacuum cleaners show promise for both sampling and initial decontamination of indoor flooring. In the event of a bioterror incident, e.g. deliberate release of Bacillus anthracis spores, areas require sampling to determine the magnitude and extent of contamination, and to establish decontamination efficacy. In this study we investigate robotic sampling methods against high concentrations of bacterial spores applied by wet deposition to different floorings, contamination spread to other areas, potential transfer of spores to the operators and assessment of a wet vacuum robot for spore inactivation. The robots' usability was evaluated and how they can be employed in real life scenarios. This will help to reduce the economic cost of sampling and the risk to sampling/decontamination teams. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Spatial distribution of ammonium and calcium in optimally fertilized pine plantation soils

Treesearch

Ivan Edwards; Andrew Gillespie; Jennifer Chen; Kurt Johnsen; Ronald Turco

2005-01-01

Commercial timber production is increasingly reliant on long-term fertilization to maximize stand productivity, yet we do not understand the extent to which this practice homogenizes soil properties. The effects of 16 yr of optimal fertilization and optimal fertilization with irrigation (fertigation) on forest floor depth, pH, total organic carbon (TOC) and total...

Deck boards to floor boards

Treesearch

Carolee A. Boyles

2004-01-01

Research shows that discarded pallets account for more than 2% of the solid waste found in the nation’s municipal landfills. In addition, more than 38% of hardwoods harvested in the country goes into the manufacture of pallets. This article describes a collaboration between North Carolina State University, the U.S. Forest Service and Waste Reduction Partners to...

Effects of organic matter removal, soil compaction, and vegetation control on Collembolan populations

Treesearch

Robert J. Eaton; Mary Barbercheck; William D. Smith

2004-01-01

Collembola can be among the most numerous meso-invertebrates in the forest floor and, through their interaction with primary decomposers in the decomposition food web, may affect litter decomposition and consequently site productivity. This study was conducted to determine whether Collembolan abundance could be impacted by organic matter removal, compaction, and...

Soil and forest floor characteristics

Treesearch

Ralph E. J. Boerner; Sherri J. Morris; Kelly L. M. Decker; Todd F. Hutchinson

2003-01-01

The soils of the four study areas in southern Ohio were dominated by silt loams derived from sandstones and shales. The soils at Bluegrass Ridge (BR) had significantly more clay and sand and significantly less silt than soils of the other study areas. Total inorganic N (TIN) and available NH4 were greatest in soils from Watch Rock (WR) and least...

Effects of climate change on nonforest vegetation [Chapter 7

Treesearch

Wayne G. Padgett; Matthew C. Reeves; Stanley G. Kitchen; David L. Tart; Jeanne C. Chambers; Cheri Howell; Mary E. Manning; John G. Proctor

2018-01-01

Nonforest ecosystems, as they are addressed in this chapter, contain woodland, shrubland, herbaceous, wetland, or riparian vegetation types. They are estimated to occupy over 30 million acres and 50 percent of the U.S. Department of Agriculture Forest Service (USFS) Intermountain Region (table 7.1). These diverse ecosystems range in elevation from desert floors to...

Eastern white pine: production, markets, and marketing of primary manufacturers

Treesearch

Delton Alderman; Paul Duvall; Robert Smith; Scott Bowe

2007-01-01

Eastern white pine (EWP) production and manufacturing have been a staple of the forest products industry since the arrival of the first settlers in the United States. Current EWP market segments range from cabinets to flooring to log cabins to moulding to toys. Today's EWP producers and manufacturers are faced with unprecedented challenges from substitute products...

Soil compaction and organic matter affect conifer seedling nonmycorrhizal and ectomycorrhizal root tip abundance and diversity.

Treesearch

Michael P. Amaranthus; Debbie Page-Dumroese; Al Harvey; Efren Cazares; Larry F. Bednar

1996-01-01

Three levels of organic matter removal (bole only; bole and crowns; and bole, crowns, and forest floor) and three levels of mechanical soil compaction (no compaction, moderate compaction, and severe soil compaction) were studied as they influence Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) and western white...

Quantifying Ladder Fuels: A New Approach Using LiDAR

Treesearch

Heather Kramer; Brandon Collins; Maggi Kelly; Scott Stephens

2014-01-01

We investigated the relationship between LiDAR and ladder fuels in the northern Sierra Nevada, California USA. Ladder fuels are often targeted in hazardous fuel reduction treatments due to their role in propagating fire from the forest floor to tree crowns. Despite their importance, ladder fuels are difficult to quantify. One common approach is to calculate canopy base...

Soil CO2 evolution and root respiration in 11 year-old Loblolly Pine (Pinus taeda) Plantations as Affected by Moisture and Nutrient Availability

Treesearch

Chris A. Maier; L.W. Kress

2000-01-01

We measured soil CO2 evolution rates with (Sff) and without (Sms) the forest floor litter and root respiration monthly in 11-year-old loblolly pine (Pinus taeda L.) plantations during the fourth year of fertilization and irrigation treatments. Values of Sff...

A probabilistic approach to modeling postfire erosion after the 2009 Australian bushfires

Treesearch

P. R. Robichaud; W. J. Elliot; F. B. Pierson; D. E. Hall; C. A. Moffet

2009-01-01

Major concerns after bushfires and wildfires include increased flooding, erosion and debris flows due to loss of the protective forest floor layer, loss of water storage, and creation of water repellent soil conditions. To assist postfire assessment teams in their efforts to evaluate fire effects and make postfire treatment decisions, a web-based Erosion Risk...

Spatial patterns in carbon storage in a lake states' landscape

Treesearch

J. C. Bell; D. F. Grigal; P. C. Bates; C. A. Butler

1996-01-01

We estimated total organic carbon storage (C -- kg m-2) in biomass, forest floor, and soil for a gently undulating glacial outwash landscape in east-central Minnesota (45° 25'N, 93° 10'W). Abandoned agricultural tracts are common, and nearly 40 percent of the area is wet mineral or organic soil. Quantitative models...

Early Holocene Great Salt Lake

USGS Publications Warehouse

Oviatt, Charles G.; Madsen, David B.; Miller, David; Thompson, Robert S.; McGeehin, John P.

2015-01-01

Shorelines and surficial deposits (including buried forest-floor mats and organic-rich wetland sediments) show that Great Salt Lake did not rise higher than modern lake levels during the earliest Holocene (11.5–10.2 cal ka BP; 10–9 14C ka BP). During that period, finely laminated, organic-rich muds (sapropel) containing brine-shrimp cysts and pellets and interbedded sodium-sulfate salts were deposited on the lake floor. Sapropel deposition was probably caused by stratification of the water column — a freshwater cap possibly was formed by groundwater, which had been stored in upland aquifers during the immediately preceding late-Pleistocene deep-lake cycle (Lake Bonneville), and was actively discharging on the basin floor. A climate characterized by low precipitation and runoff, combined with local areas of groundwater discharge in piedmont settings, could explain the apparent conflict between evidence for a shallow lake (a dry climate) and previously published interpretations for a moist climate in the Great Salt Lake basin of the eastern Great Basin.

FLOOR PLAN OF MAIN PROCESSING BUILDING (CPP601), FIRST FLOOR SHOWING ...

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

FLOOR PLAN OF MAIN PROCESSING BUILDING (CPP-601), FIRST FLOOR SHOWING SAMPLE CORRIDORS AND EIGHTEEN CELLS AND ADJOINING REMOTE ANALYTICAL FACILITY (CPP-627) SHOWING REMOTE ANALYTICAL FACILITIES LAB, DECONTAMINATION ROOM, AND MULTICURIE CELL ROOM. TO LEFT ARE LABORATORY BUILDING (CPP-602) AND MAINTENANCE BUILDING (CPP-630). INL DRAWING NUMBER 200-0601-00-706-051979. ALTERNATE ID NUMBER CPP-E-1979. - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID

Extracting Features of Acacia Plantation and Natural Forest in the Mountainous Region of Sarawak, Malaysia by ALOS/AVNIR2 Image

NASA Astrophysics Data System (ADS)

Fadaei, H.; Ishii, R.; Suzuki, R.; Kendawang, J.

2013-12-01

The remote sensing technique has provided useful information to detect spatio-temporal changes in the land cover of tropical forests. Land cover characteristics derived from satellite image can be applied to the estimation of ecosystem services and biodiversity over an extensive area, and such land cover information would provide valuable information to global and local people to understand the significance of the tropical ecosystem. This study was conducted in the Acacia plantations and natural forest situated in the mountainous region which has different ecological characteristic from that in flat and low land area in Sarawak, Malaysia. The main objective of this study is to compare extract the characteristic of them by analyzing the ALOS/AVNIR2 images and ground truthing obtained by the forest survey. We implemented a ground-based forest survey at Aacia plantations and natural forest in the mountainous region in Sarawak, Malaysia in June, 2013 and acquired the forest structure data (tree height, diameter at breast height (DBH), crown diameter, tree spacing) and spectral reflectance data at the three sample plots of Acacia plantation that has 10 x 10m area. As for the spectral reflectance data, we measured the spectral reflectance of the end members of forest such as leaves, stems, road surface, and forest floor by the spectro-radiometer. Such forest structure and spectral data were incorporated into the image analysis by support vector machine (SVM) and object-base/texture analysis. Consequently, land covers on the AVNIR2 image were classified into three forest types (natural forest, oil palm plantation and acacia mangium plantation), then the characteristic of each category was examined. We additionally used the tree age data of acacia plantation for the classification. A unique feature was found in vegetation spectral reflectance of Acacia plantations. The curve of the spectral reflectance shows two peaks around 0.3μm and 0.6 - 0.8μm that can be assumed to be corresponded to the reflectance from the bare land part (soil) and forest crown in the Acacia forest, respectively. In accordance with this spectral characteristic, we can estimate the proportional areas of the bare land and crown cover of the tree in the acacia plantation forest that will provide essential information for evaluating the forest ecosystem. We will define Bare land and Tree Crown Ratio Index (BTRI) that represent ratio of the areas of tree crown to areas of their access roads. Such information will delineate the characteristics of Acacia plantation and natural forest in mountainous region, and enable us to compare them with the plantation and forest in flat and low land.

High mercury accumulation in two subtropical evergreen forests in South China and potential determinants.

PubMed

Lu, Zhiyun; Wang, Xun; Zhang, Yiping; Zhang, Yong-Jiang; Luo, Kang; Sha, Liqing

2016-12-01

Forests play an important role in global mercury (Hg) cycling. To explain the high Hg accumulation in subtropical forest ecosystems, we studied temporal dynamics of Hg, carbon (C), nitrogen (N), and sulfur (S) in forest soil profiles, as well as litterfall flux and precipitation, in an old-growth moist evergreen broadleaf (EB) forest and a mossy coppice (MC) forest from South China over seven years. The mean soil Hg concentration was 257 ± 14 ng g -1 in the O-horizon and 248 ± 15 ng g -1 in the A-horizon for the EB forest, and 94 ± 27 ng g -1 in the O-horizon and 70 ± 11 ng g -1 in the A-horizon for the MC forest. Annual variations in Hg concentration were suggested to be associated with variations in precipitation and litterfall biomass. Significant vertical Hg transport was only observed in the MC forest, which was attributed to its lower organic matter content. Correlation and stoichiometry analyses further suggested that the dynamics in Hg concentration in the forest floor was also closely linked to the variation in S concentration. Additionally, the difference in the soil Hg pool between these two forests was attributed to different litterfall biomass fluxes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Barriers to seed and seedling survival of once-common Hawaiian palms: the role of invasive rats and ungulates

PubMed Central

Shiels, Aaron B.; Drake, Donald R.

2015-01-01

Mammalian herbivores can limit plant recruitment and affect forest composition. Loulu palms (Pritchardia spp.) once dominated many lowland ecosystems in Hawai‘i, and non-native rats (Rattus spp.), ungulates (e.g. pigs Sus scrofa, goats Capra hircus) and humans have been proposed as major causes of their decline. In lowland wet forest, we experimentally determined the vulnerability of seeds and seedlings of two species of Pritchardia, P. maideniana and P. hillebrandii, by measuring their removal by introduced vertebrates; we also used motion-sensing cameras to identify the animals responsible for Pritchardia removal. We assessed potential seed dispersal of P. maideniana by spool-and-line tracking, and conducted captive-feeding trials with R. rattus and seeds and seedlings of both Pritchardia species. Seed removal from the forest floor occurred rapidly for both species: >50 % of Pritchardia seeds were removed from the vertebrate-accessible stations within 6 days and >80 % were removed within 22 days. Although rats and pigs were both common to the study area, motion-sensing cameras detected only rats (probably R. rattus) removing Pritchardia seeds from the forest floor. Captive-feeding trials and spool-and-line tracking revealed that vertebrate seed dispersal is rare; rats moved seeds up to 8 m upon collection and subsequently destroyed them (100 % mortality in 24–48 h in captivity). Surprisingly, seedlings did not suffer vertebrate damage in field trials, and although rats damaged seedlings in captivity, they rarely consumed them. Our findings are consistent with the hypothesis generated from palaeoecological studies, indicating that introduced rats may have assisted in the demise of native insular palm forests. These findings also imply that the seed stage of species in this Pacific genus is particularly vulnerable to rats; therefore, future conservation efforts involving Pritchardia should prioritize the reduction of rat predation on the plant recruitment stages preceding seedling establishment. PMID:26019231

Where's the dust? Characterizing locations of azinphos-methyl residues in house and vehicle dust among farmworkers with young children.

PubMed

Coronado, Gloria D; Griffith, William C; Vigoren, Eric M; Faustman, Elaine M; Thompson, Beti

2010-12-01

Organophosphate pesticides are commonly used in the United States, and farmworkers are at risk for chronic exposure. Using data from a community randomized trial to interrupt the take-home pathway of pesticide exposure, we examined the association between floor surface type (smooth floor, thin carpet, and thick carpet) and rooms in which dust samples were collected (living room vs. non-living room) and concentrations of azinphos-methyl residues in home environments. We also examined the association between vehicle type (truck, auto, or other) and footwell floor surfaces (carpeted, smooth surface, or no mat) and concentrations of azinphos-methyl in vehicle dust samples. Dust samples were collected from 203 and 179 households and vehicles, respectively. All households had at least one child aged 2-6. Vehicle dust samples were collected from footwells of the vehicle used for commuting to and from work. A total of 183 samples were collected from living rooms, and 20 were collected from other rooms in the home. Forty-two samples were collected from thick carpets, 130 from thin carpets, and 27 from smooth floor surfaces. Thick and thin carpets had a significantly greater dust mass than smooth floor surfaces (6.0 g/m(2) for thick carpets, 7.8 g/m(2) for thin carpets, and 1.5 g/m(2) for smooth surfaces). Of the 179 vehicle samples, 113 were from cars, 34 from trucks, and 32 from other vehicles. Vehicles with no mats had a significantly higher mass of dust (21.3 g) than those with hard mats (9.3 g) but did not differ from vehicles with plush mats (12.0 g). Further research is needed to characterize the environment in which children may be exposed to pesticides.