Science.gov

Sample records for evergreen forest type

  1. Comparing Temporal Variations in LUE and GPP across Evergreen and Deciduous Forest Types

    NASA Astrophysics Data System (ADS)

    Zhou, Y.; Hilker, T.; Ju, W.; Coops, N. C.; Black, T. A.; Chen, J.

    2015-12-01

    Estimating gross primary production (GPP) is an important goal of global change research. However, the relationship between GPP and its environmental drivers is highly complex and as a result, accurate modeling of GPP is difficult. One possible technique to help constrain the uncertainties is by using remote sensing data to try and determine the factors driving GPP directly from satellite imagery. In this study, we used GPP from flux data (GPP_EC) and meteorological observations of a deciduous (SOA) and a coniferous evergreen forest (DF-49) to optimize light use efficiency of sunlit (LUEsun) and shaded (LUEshaded) canopies. We based our analysis on the two-leave light use efficiency model (TL-LUE) at daily, 8 day, and 16 day scales by using the Markov chain Monte Carlo (MCMC). The photochemical reflectance index (PRI) of sunlit (PRIsun) and shaded (PRIshaded) leaves was calculated from spectral observations and related to tower based GPP at the three temporal scales. We found that the coefficient of determination (R2) between PRIsun and LUEsun, as well as PRIshaded and LUEshaded at the evergreen forest was lower than that at the deciduous forest. The modeled GPP was closely to the GPP_EC at the three temporal scales. The R2 between the GPP_EC and modeled daily GPP was the highest when using daily measures of LUE, and lowest when uisng16-day LUEsun and LUEshaded. The results indicated that LUE is an important parameter when modeling instantaneous GPP and the short term variations of it. The results help to obtain a better understanding of how many satellite observations are needed to reliably constrain existing GPP models from remote sensing data.

  2. Carbon of Woody Debris in Plateau-type Karst Evergreen and Deciduous Broad-leaved Mixed Forest of Central Guizhou Province

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Ni, J.; Liu, L.; Guo, C.

    2014-12-01

    Woody debris (WD) is an essential structural and functional component of forest ecosystems, and plays very significant roles for the biogeochemical cycling of carbon and nutrients. Coarse woody debris (CWD) is considered to be the major part in forest WD and it is primarily composed of logs, snags, stumps and large branches, while fine woody debris (FWD) mainly consists of small twigs. Composition, spatial distribution and carbon storage of WD have been studied in plateau-type karst evergreen and deciduous broad-leaved mixed forest in Tianlong Mountain of central Guizhou Province. Results showed that the carbon storage of WD in karst forests was less than non-karst forests. The major components of WD were fallen trees and snags with 10-20 cm in diameter. Fallen trees and snags with diameter greater than 20 cm were the smallest part of WD. The situation of WD in this region reflects the structural characteristics of WD in mid-late stage of plateau-type karst evergreen and deciduous broad-leaved mixed forest succession. The potential contribution of WD to the regional carbon cycle, and its relationship with climate change were finally discussed. The WD (especially CWD) plays an important role in the carbon cycle of karst forest. Forest WD production and decay rates may partially depend on climatic conditions, the accumulation of CWD and FWD carbon stocks in forests may be correlated with climate. Key words: woody debris, karst forests, carbon storage, spatial distribution, CWD, FWD.

  3. An Old-Growth Definition for Evergreen Bay Forests and Related Seral Communities

    Treesearch

    Martha R. McKevlin

    1996-01-01

    This document describes old-growth conditions in an evergreen bay forest stand. Bay forests occur throughout the Atlantic and Gulf Coastal Plains. However, they are considered rare and are present across the landscape in a patchwork mosaic with other forest types in various stages of succession. Bay forests can be found associated with pocosins, Carolina bays and...

  4. Evergreen understory dynamics in Coweeta forest, North Carolina

    Treesearch

    M.M. Dobbs; Albert J. Parker

    2004-01-01

    A number of studies have elucidated the distributional patterns of various components of Southern Appalachian forests. The evergreen understory here is composed largely of a dominant ericaceous shrub, Rhododendron maximum L., which is believed to be expanding and inhibiting the development of other species with consequent impacts on overall forest...

  5. 29 CFR 780.1016 - Use of evergreens and forest products.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Use of evergreens and forest products. 780.1016 Section 780... Labor Provisions Under Section 13(d) Requirements for Exemption § 780.1016 Use of evergreens and forest products. Harvesting of evergreens and other forest products is exempt only when these products will be...

  6. 29 CFR 780.1016 - Use of evergreens and forest products.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Use of evergreens and forest products. 780.1016 Section 780... Labor Provisions Under Section 13(d) Requirements for Exemption § 780.1016 Use of evergreens and forest products. Harvesting of evergreens and other forest products is exempt only when these products will be...

  7. 29 CFR 780.1016 - Use of evergreens and forest products.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Use of evergreens and forest products. 780.1016 Section 780... Labor Provisions Under Section 13(d) Requirements for Exemption § 780.1016 Use of evergreens and forest products. Harvesting of evergreens and other forest products is exempt only when these products will be...

  8. 29 CFR 780.1016 - Use of evergreens and forest products.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Use of evergreens and forest products. 780.1016 Section 780... Labor Provisions Under Section 13(d) Requirements for Exemption § 780.1016 Use of evergreens and forest products. Harvesting of evergreens and other forest products is exempt only when these products will be...

  9. 29 CFR 780.1016 - Use of evergreens and forest products.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Use of evergreens and forest products. 780.1016 Section 780... Labor Provisions Under Section 13(d) Requirements for Exemption § 780.1016 Use of evergreens and forest products. Harvesting of evergreens and other forest products is exempt only when these products will be...

  10. Predicting vegetation type through physiological and environmental interactions with leaf traits: evergreen and deciduous forests in an earth system modeling framework.

    PubMed

    Weng, Ensheng; Farrior, Caroline E; Dybzinski, Ray; Pacala, Stephen W

    2017-06-01

    Earth system models are incorporating plant trait diversity into their land components to better predict vegetation dynamics in a changing climate. However, extant plant trait distributions will not allow extrapolations to novel community assemblages in future climates, which will require a mechanistic understanding of the trade-offs that determine trait diversity. In this study, we show how physiological trade-offs involving leaf mass per unit area (LMA), leaf lifespan, leaf nitrogen, and leaf respiration may explain the distribution patterns of evergreen and deciduous trees in the temperate and boreal zones based on (1) an evolutionary analysis of a simple mathematical model and (2) simulation experiments of an individual-based dynamic vegetation model (i.e., LM3-PPA). The evolutionary analysis shows that these leaf traits set up a trade-off between carbon- and nitrogen-use efficiency at the scale of individual trees and therefore determine competitively dominant leaf strategies. As soil nitrogen availability increases, the dominant leaf strategy switches from one that is high in nitrogen-use efficiency to one that is high in carbon-use efficiency or, equivalently, from high-LMA/long-lived leaves (i.e., evergreen) to low-LMA/short-lived leaves (i.e., deciduous). In a region of intermediate soil nitrogen availability, the dominant leaf strategy may be either deciduous or evergreen depending on the initial conditions of plant trait abundance (i.e., founder controlled) due to feedbacks of leaf traits on soil nitrogen mineralization through litter quality. Simulated successional patterns by LM3-PPA from the leaf physiological trade-offs are consistent with observed successional dynamics of evergreen and deciduous forests at three sites spanning the temperate to boreal zones. © 2016 John Wiley & Sons Ltd.

  11. Monitoring Spring Recovery of Photosynthesis and Spectral Reflectance in Temperate Evergreen and Mixed Deciduous Forests

    NASA Astrophysics Data System (ADS)

    Wong, C. Y.; Arain, M. A.; Ensminger, I.

    2015-12-01

    Evergreen conifers in boreal and temperate regions undergo strong seasonal changes in photoperiod and temperatures, which characterizes their photosynthetic activity with high activity in the growing season and downregulation during the winter season. Monitoring the timing of the transitions in evergreens is difficult since it's a largely invisible process, unlike deciduous trees that have a visible budding and senescence sequence. Spectral reflectance and the photochemical reflectance index (PRI), often used as a proxy for photosynthetic light-use efficiency, provides a promising tool to track the transition of evergreens between inactive and active photosynthetic states. To better understand the relationship between PRI and photosynthetic activity and to contrast this relationship between plant functional types, the spring recovery of an evergreen forest and mixed deciduous forest was monitored using spectral reflectance, chlorophyll fluorescence and gas exchange. All metrics indicate photosynthetic recovery during the spring season. These findings indicate that PRI can be used to observe the spring recovery of photosynthesis in evergreen conifers but may not be best suited for deciduous trees. These findings have implications for remote sensing, which provides a promising long-term monitoring system of whole ecosystems, which is important since their roles in the carbon cycle may shift in response to climate change.

  12. Litterfall production along successional and altitudinal gradients of subtropical monsoon evergreen broadleaved forests in Guangdong, China

    USGS Publications Warehouse

    Zhou, G.; Guan, L.; Wei, X.; Zhang, Dongxiao; Zhang, Q.; Yan, J.; Wen, D.; Liu, J.; Liu, S.; Huang, Z.; Kong, G.; Mo, J.; Yu, Q.

    2007-01-01

    Evaluation of litterfall production is important for understanding nutrient cycling, forest growth, successional pathways, and interactions with environmental variables in forest ecosystems. Litterfall was intensively studied during the period of 1982-2001 in two subtropical monsoon vegetation gradients in the Dinghushan Biosphere Reserve, Guangdong Province, China. The two gradients include: (1) a successional gradient composed of pine forest (PF), mixed pine and broadleaved forest (MF) and monsoon evergreen broadleaved forest (BF), and (2) an altitudinal gradient composed of Baiyunci ravine rain forest (BRF), Qingyunci ravine rain forest (QRF), BF and mountainous evergreen broadleaved forest (MMF). Mean annual litterfall production was 356, 861 and 849 g m-2 for PF, MF and BF of the successional gradient, and 1016, 1061, 849 and 489 g m-2 for BRF, QRF, BF and MMF of the altitudinal gradient, respectively. As expected, mean annual litterfall of the pioneer forest PF was the lowest, but rapidly increased over the observation period while those in other forests were relatively stable, confirming that forest litterfall production is closely related to successional stages and growth patterns. Leaf proportions of total litterfall in PF, MF, BF, BRF, QRF and MMF were 76.4%, 68.4%, 56.8%, 55.7%, 57.6% and 69.2%, respectively, which were consistent with the results from studies in other evergreen broadleaved forests. Our analysis on litterfall monthly distributions indicated that litterfall production was much higher during the period of April to September compared to other months for all studied forest types. Although there were significant impacts of some climate variables (maximum and effective temperatures) on litterfall production in some of the studied forests, the mechanisms of how climate factors (temperature and rainfall) interactively affect litterfall await further study. ?? 2006 Springer Science+Business Media B.V.

  13. Protected areas: mixed success in conserving East Africa's evergreen forests.

    PubMed

    Pfeifer, Marion; Burgess, Neil D; Swetnam, Ruth D; Platts, Philip J; Willcock, Simon; Marchant, Robert

    2012-01-01

    In East Africa, human population growth and demands for natural resources cause forest loss contributing to increased carbon emissions and reduced biodiversity. Protected Areas (PAs) are intended to conserve habitats and species. Variability in PA effectiveness and 'leakage' (here defined as displacement of deforestation) may lead to different trends in forest loss within, and adjacent to, existing PAs. Here, we quantify spatial variation in trends of evergreen forest coverage in East Africa between 2001 and 2009, and test for correlations with forest accessibility and environmental drivers. We investigate PA effectiveness at local, landscape and national scales, comparing rates of deforestation within park boundaries with those detected in park buffer zones and in unprotected land more generally. Background forest loss (BFL) was estimated at -9.3% (17,167 km(2)), but varied between countries (range: -0.9% to -85.7%; note: no BFL in South Sudan). We document high variability in PA effectiveness within and between PA categories. The most successful PAs were National Parks, although only 26 out of 48 parks increased or maintained their forest area (i.e. Effective parks). Forest Reserves (Ineffective parks, i.e. parks that lose forest from within boundaries: 204 out of 337), Nature Reserves (six out of 12) and Game Parks (24 out of 26) were more likely to lose forest cover. Forest loss in buffer zones around PAs exceeded background forest loss, in some areas indicating leakage driven by Effective National Parks. Human pressure, forest accessibility, protection status, distance to fires and long-term annual rainfall were highly significant drivers of forest loss in East Africa. Some of these factors can be addressed by adjusting park management. However, addressing close links between livelihoods, natural capital and poverty remains a fundamental challenge in East Africa's forest conservation efforts.

  14. The impact of boreal deciduous and evergreen forests on atmospheric CO2 seasonality

    NASA Astrophysics Data System (ADS)

    Welp, L.; Graven, H. D.; Keeling, R. F.; Bi, J.

    2015-12-01

    The seasonal cycle of atmospheric CO2 is largely controlled by the terrestrial biosphere. It is well known that the seasonal amplitude of net ecosystem productivity (NEP) is the largest in the far north, where forest productivity is compressed into a short growing season. Since 1960, the seasonal amplitude of atmospheric CO2 north of 45N has increased by 35-55%. The increase in the seasonal amplitude is a difficult benchmark for coupled climate-carbon models to replicate. In fact, the models vary widely in their mean seasonal cycle representation. The boreal region has a strong influence on CO2 seasonality at Barrow. Deciduous and evergreen plant functional types (PFTs) have different patterns of NEP. We identified four pairs of nearby deciduous and evergreen forest PFTs with eddy covariance measurements. Evergreen forests show an early peak in NEP in May-June, while deciduous forests have a larger peak in NEP later in June-July. The influence of each PFT on the seasonal cycle at Barrow was computed from atmospheric transport results. We normalized the amplitude influence by the growing season NEP of the tower-based PFT flux and found that deciduous forests have 1.4 to 1.8 times more influence (per unit of growing season NEP) at Barrow than evergreen PFT. This diagnosis depends on the timing of the sharp seasonal draw-down at Barrow, which occurs too late to be explained by evergreen forests. The cycle at Barrow therefore appears to be strongly influenced by deciduous PFT, despite the dominance of evergreen PFTs in boreal forests. This paradoxical conclusion is also reached when examining the seasonality of land surface fluxes calculated using atmospheric inverse methods. We examine how these different PFTs, and possible trends in relative abundance, affect the seasonality of atmosphere CO2 using FluxNet data and atmospheric transport modelling. Our results highlight the importance of parameterizing multiple PFTs or individual species within grid cells in models in

  15. Modeling acclimation of photosynthesis to temperature in evergreen conifer forests.

    PubMed

    Gea-Izquierdo, Guillermo; Mäkelä, Annikki; Margolis, Hank; Bergeron, Yves; Black, T Andrew; Dunn, Allison; Hadley, Julian; Kyaw Tha Paw U; Falk, Matthias; Wharton, Sonia; Monson, Russell; Hollinger, David Y; Laurila, Tuomas; Aurela, Mika; McCaughey, Harry; Bourque, Charles; Vesala, Timo; Berninger, Frank

    2010-10-01

    • In this study, we used a canopy photosynthesis model which describes changes in photosynthetic capacity with slow temperature-dependent acclimations. • A flux-partitioning algorithm was applied to fit the photosynthesis model to net ecosystem exchange data for 12 evergreen coniferous forests from northern temperate and boreal regions. • The model accounted for much of the variation in photosynthetic production, with modeling efficiencies (mean > 67%) similar to those of more complex models. The parameter describing the rate of acclimation was larger at the northern sites, leading to a slower acclimation of photosynthesis to temperature. The response of the rates of photosynthesis to air temperature in spring was delayed up to several days at the coldest sites. Overall photosynthesis acclimation processes were slower at colder, northern locations than at warmer, more southern, and more maritime sites. • Consequently, slow changes in photosynthetic capacity were essential to explaining variations of photosynthesis for colder boreal forests (i.e. where acclimation of photosynthesis to temperature was slower), whereas the importance of these processes was minor in warmer conifer evergreen forests.

  16. Old-growth definition for evergreen bay forests and related seral communities. Forest Service general technical report

    SciTech Connect

    McKevlin, M.R.

    1996-09-01

    This document describes old-growth conditions in an evergreen bay forest stand. Bay forests occur throughout the Atlantic and Gulf Coastal Plains. However, they are considered rare and are present across the landscape in a patchwork mosaic with other forest types in various stages of succession. Bay forests can be found associated with pocosins. Carolina bays and sandhill seeps, stream heads, and stream margins. The dominant species include loblolly-bay, sweetbay, and redbay, hence the name evergreen bay forest. However, several other swamp species associates are common, as well as many highly flammable shrub species. This forest type is subject to infrequent, high intensity, widespread disturbances such as fire. Fire is necessary to the nutrient cycling of this forest type and in conjunction with hydrology, controls succession. These stands are frequently inundated by surface water, resulting in the development of histic soils low in fertility. Alteration of the hydrology by man and catastrophic wildfire are considered to be the greatest threats to the existence of bay forests.

  17. Modeling seasonal canopy dynamics for tropical evergreen forests

    NASA Astrophysics Data System (ADS)

    De Weirdt, M.; Verbeeck, H.; Maignan, F.; Poulter, B.; Peylin, P.; Ciais, P.; Moreau, I.; Hanert, E.; Defourny, P.; Steppe, K.

    2011-12-01

    The role of seasonal phenology in tropical humid forests on canopy photosynthesis remains poorly understood and its representation in global vegetation models highly simplified, typically with no seasonal and interannual variability of canopy leaf area properties taken into account. However, recent flux tower and remote sensing studies suggest that seasonal phenology in tropical rainforests exerts a large influence over carbon and water fluxes, with feedbacks that can significantly influence climate dynamics. A more realistic description of the underlying mechanisms that drive seasonal tropical forest photosynthesis and phenology could possibly improve the correspondence of global vegetation model outputs with the wet-dry season biogeochemical patterns measured at flux tower sites. Here, we introduce a leaf phenology and radiation based canopy dynamics scheme for evergreen tropical forests in the global terrestrial ecosystem model ORCHIDEE and validated this new scheme against in-situ carbon flux measurements. Two different model formulations were introduced and tested separately: the first mechanism was a radiation based seasonal change in photosynthetic capacity of the canopy, and the second mechanism consisted of a seasonal leaf litterfall module, that induces a seasonal change in photosynthetic capacity via leaf age. Modeled gross primary productivity (GPP) patterns are analyzed in detail for a flux tower site in French Guiana, in a forest where the dry season is short and where the vegetation is considered to have developed adaptive mechanisms against drought stress. By including tropical forest leaf litterfall and a subsequent light-driven leaf flush in ORCHIDEE, modeled carbon and water fluxes more accurately represented observations. The fit to GPP flux data was substantially improved and the results confirm that by modifying canopy dynamics to benefit from increased light conditions, a better representation of the seasonal carbon flux patterns is made.

  18. Unravelling carbon allocation dynamics in an evergreen temperate forest

    NASA Astrophysics Data System (ADS)

    Griebel, Anne; Bennett, Lauren T.; Arndt, Stefan K.

    2015-04-01

    Eucalypt trees have the potential to sequester carbon from the atmosphere year-round by maintaining evergreen leaves with a prolonged multi-year lifetime. Unlike deciduous trees, eucalypts are generally known to grow opportunistic resulting in a lack of defined growth rings and no distinct seasonal crown turnover events. Stem expansion has been successfully measured with micro-dendrometers, however, it remains challenging to monitor crown dynamics at a similarly high temporal resolution. Hence, carbon allocation dynamics and seasonal variations of carbon distribution between stem and crown biomass remain largely unknown for evergreen species. Ecosystem scale observations of net ecosystem exchange (NEE) from a flux tower located in a predominantly temperature and moisture regulated environment in south-eastern Australia have demonstrated that the ecosystem is a constant terrestrial sink for carbon. Intra-annual variations in temperature and moisture and prolonged heat waves and dry spells result in a wide range of annual sums (e.g. 2013: NEE~4 t C ha-1yr-1, 2012: NEE~12 t C ha-1yr-1). Newly developed low-cost terrestrial lidar sensors (VEGNET) now allow for automated daily monitoring of crown dynamics, enabling more detailed observations on the duration of crown biomass changes. In addition to leaf area index (LAI), VEGNET sensors define the location within the crown strata of the gains and losses in plant volume across the vertical forest structure. With the development of VEGNET sensors, combined with ecosystem carbon fluxes from eddy covariance measurements and with micro-dendrometers, we are able to quantify the dynamics of carbon allocation to above ground biomass pools. Our results demonstrate that stem growth dominates in spring and in autumn, and is strongly associated with water availability. Leaf turnover predominantly takes place in summer and is initiated by prolonged heat stress and isolated storm events, yet crown biomass remains stable throughout the

  19. Belowground carbon balance and carbon accumulation rate in the successional series of monsoon evergreen broad-leaved forest

    USGS Publications Warehouse

    Zhou, G.; Liu, S.; Tang, X.; Ouyang, X.; Zhang, Dongxiao; Liu, J.; Yan, J.; Zhou, C.; Luo, Y.; Guan, L.; Liu, Yajing

    2006-01-01

    The balance, accumulation rate and temporal dynamics of belowground carbon in the successional series of monsoon evergreen broadleaved forest are obtained in this paper, based on long-term observations to the soil organic matter, input and standing biomass of litter and coarse woody debris, and dissolved organic carbon carried in the hydrological process of subtropical climax forest ecosystem—monsoon evergreen broad-leaved forest, and its two successional forests of natural restoration—coniferous and broad-leaved mixed forest and Pinus massoniana forest, as well as data of root biomass obtained once every five years and respiration measurement of soil, litter and coarse woody debris respiration for 1 year. The major results include: the belowground carbon pools of monsoon evergreen broad-leaved forest, coniferous and broad-leaved mixed forest, and Pinus massoniana forest are 23191 ± 2538 g · m−2, 16889 ± 1936 g · m−2 and 12680 ± 1854 g · m−2, respectively, in 2002. Mean annual carbon accumulation rates of the three forest types during the 24a from 1978 to 2002 are 383 ± 97 g · m−2 · a−1, 193 ± 85 g · m−2 · a−1 and 213 ± 86 g · m−2 · a−1, respectively. The belowground carbon pools in the three forest types keep increasing during the observation period, suggesting that belowground carbon pools are carbon sinks to the atmosphere. There are seasonal variations, namely, they are strong carbon sources from April to June, weak carbon sources from July to September; while they are strong carbon sinks from October to November, weak carbon sinks from December to March.

  20. Ecology of subtropical evergreen broad-leaved forests of Yunnan, southwestern China as compared to those of southwestern Japan.

    PubMed

    Tang, Cindy Q; Ohsawa, Masahiko

    2009-05-01

    Subtropical evergreen broad-leaved forests of Yunnan, China, including mid-montane moist, monsoon, and semi-humid categories, were studied in terms of ecological attributes of pertinent species, diversity, structure, dynamics and succession, as compared with the subtropical/warm-temperate evergreen broad-leaved rain forest of southwestern (SW) Japan. The genera and species of the forests of Yunnan and SW Japan are East Asian elements and indicate a very close relationship between the respective floras, though different assemblages of species occur in the two regions. Diversity indices and numerical data on taxon richness at family, genus and species level were similar in both regions. Four types of gap-regeneration behaviors among the major tree species were recognized in the two areas. In both, as a result of long-term human activity, the plant communities ranged from pioneer deciduous broad-leaved and/or pioneer coniferous stands to late-successional evergreen broad-leaved stands. Succession in the two regions followed parallel paths, beginning with pioneer Alnus in Yunnan and Alnus, Mallotus and Styrax in Japan, accompanied by coniferous Pinus in the two areas, and with late-successional evergreen broad-leaved Cyclobalanopsis and Castanopsis as their final stage.

  1. Ecology of Phytophthora nemorosa and Phytophthora pseudosyringae in mixed-evergreen forests

    Treesearch

    Allison C. Wickland; David M. Rizzo

    2006-01-01

    Recent research has shown that Phytophthora ramorum is a major threat to California’s coast live oak (Quercus agrifolia) dominated, mixed-evergreen forests (Rizzo and Garbelotto 2003). However, the role that diseases caused by other Phytophthora species play in the ecology of these forest communities is less...

  2. Allometric Equations for Aboveground and Belowground Biomass Estimations in an Evergreen Forest in Vietnam

    PubMed Central

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

    2016-01-01

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

  3. A simple algorithm for large-scale mapping of evergreen forests in tropical America, Africa and Asia

    Treesearch

    Xiangming Xiao; Chandrashekhar M. Biradar; Christina Czarnecki; Tunrayo Alabi; Michael Keller

    2009-01-01

    The areal extent and spatial distribution of evergreen forests in the tropical zones are important for the study of climate, carbon cycle and biodiversity. However, frequent cloud cover in the tropical regions makes mapping evergreen forests a challenging task. In this study we developed a simple and novel mapping algorithm that is based on the temporal profile...

  4. [Microclimate edge effects of evergreen broad-leaved forest fragments in Jinyun Mountain: a preliminary study].

    PubMed

    Yan, Min; Zhong, Zhangchen; Qiao, Xiuhong

    2006-01-01

    This paper studied the microclimate of continuous and fragmental evergreen broad-leaved forests in Jinyun Mountain by determining the horizontal gradient distribution of microclimate elements near forest edges. The results showed that there existed clear edge effects of microclimate in every edge of fragmental forests. The distinctions of maximum and minimum air temperature, photosynthetic active radiation, and minimum relative humidity between edge forest and interior forest were higher or greater, while that of maximum ground surface temperature was lower or smaller in dry season than in rain season. The edge effect was the smallest in the biggest fragmental patch, but the greatest in the smallest fragmental patch in interior forest.

  5. Fuel treatments alter the effects of wildfire in a mixed-evergreen forest, Oregon, USA.

    Treesearch

    Crystal L. Raymond; David L. Peterson

    2005-01-01

    We had the rare opportunity to quantify the relationship between fuels and fire severity using prefire surface and canopy fuel data and fire severity data after a wildfire. The study area is a mixed-evergreen forest of southwestern Oregon with a mixed-severity fire regime. Modeled fire behavior showed that thinning reduced canopy fuels, thereby decreasing the potential...

  6. Phylogeographical patterns of a generalist acorn weevil: insight into the biogeographical history of broadleaved deciduous and evergreen forests

    PubMed Central

    Aoki, Kyoko; Kato, Makoto; Murakami, Noriaki

    2009-01-01

    Background Climatic changes during glacial periods have had a major influence on the recent evolutionary history of living organisms, even in temperate forests on islands, where the land was not covered with ice sheets. We investigated the phylogeographical patterns of the weevil Curculio sikkimensis (Curculionidae), a generalist seed predator of Fagaceae plants living in both deciduous oak and evergreen forests of Japan. Its genetic structure was compared to that of another host-specific seed predator, C. hilgendorfi, inhabiting only evergreen forests. Results We examined 921 bp of mitochondrial DNA for 115 individuals collected from 33 populations of C. sikkimensis from 11 plant species of three genera, Quercus, Lithocarpus, and Castanopsis. An analysis of molecular variance revealed that a large proportion (almost 50%, P < 0.001) of the total genetic variance could be explained by differences between two geographical regions, the southwestern and northeastern parts of the main islands of Japan. In contrast, no significant genetic differentiation of the weevil was observed among vegetation types of their utilized host plant species. The phylogeographical patterns of the generalist and the host-specific seed predator exhibited a congruent genetic boundary in the Chugoku-Shikoku region. Conclusion Our results suggest that geology and historical environment have contributed to shaping the present genetic structure of C. sikkimensis. The geographical patterns of genetic differentiation in the Chugoku-Shikoku region observed in the two types of Fagaceae-associated Curculio in this study have also been observed in several plant species growing in warm and cool temperate zones of Japan. The occurrence of this common pattern suggests that deciduous oak and evergreen forests of Japan survived together, or adjacent to each other, in small refugia during glacial ages, in the southwestern and northeastern parts of the main islands, although these two types of forests are

  7. Phylogeographical patterns of a generalist acorn weevil: insight into the biogeographical history of broadleaved deciduous and evergreen forests.

    PubMed

    Aoki, Kyoko; Kato, Makoto; Murakami, Noriaki

    2009-05-16

    Climatic changes during glacial periods have had a major influence on the recent evolutionary history of living organisms, even in temperate forests on islands, where the land was not covered with ice sheets. We investigated the phylogeographical patterns of the weevil Curculio sikkimensis (Curculionidae), a generalist seed predator of Fagaceae plants living in both deciduous oak and evergreen forests of Japan. Its genetic structure was compared to that of another host-specific seed predator, C. hilgendorfi, inhabiting only evergreen forests. We examined 921 bp of mitochondrial DNA for 115 individuals collected from 33 populations of C. sikkimensis from 11 plant species of three genera, Quercus, Lithocarpus, and Castanopsis. An analysis of molecular variance revealed that a large proportion (almost 50%, P < 0.001) of the total genetic variance could be explained by differences between two geographical regions, the southwestern and northeastern parts of the main islands of Japan. In contrast, no significant genetic differentiation of the weevil was observed among vegetation types of their utilized host plant species. The phylogeographical patterns of the generalist and the host-specific seed predator exhibited a congruent genetic boundary in the Chugoku-Shikoku region. Our results suggest that geology and historical environment have contributed to shaping the present genetic structure of C. sikkimensis. The geographical patterns of genetic differentiation in the Chugoku-Shikoku region observed in the two types of Fagaceae-associated Curculio in this study have also been observed in several plant species growing in warm and cool temperate zones of Japan. The occurrence of this common pattern suggests that deciduous oak and evergreen forests of Japan survived together, or adjacent to each other, in small refugia during glacial ages, in the southwestern and northeastern parts of the main islands, although these two types of forests are presently distributed in cool and

  8. [Biomass allometric equations of nine common tree species in an evergreen broadleaved forest of subtropical China].

    PubMed

    Zuo, Shu-di; Ren, Yin; Weng, Xian; Ding, Hong-feng; Luo, Yun-jian

    2015-02-01

    Biomass allometric equation (BAE) considered as a simple and reliable method in the estimation of forest biomass and carbon was used widely. In China, numerous studies focused on the BAEs for coniferous forest and pure broadleaved forest, and generalized BAEs were frequently used to estimate the biomass and carbon of mixed broadleaved forest, although they could induce large uncertainty in the estimates. In this study, we developed the species-specific and generalized BAEs using biomass measurement for 9 common broadleaved trees (Castanopsis fargesii, C. lamontii, C. tibetana, Lithocarpus glaber, Sloanea sinensis, Daphniphyllum oldhami, Alniphyllum fortunei, Manglietia yuyuanensis, and Engelhardtia fenzlii) of subtropical evergreen broadleaved forest, and compared differences in species-specific and generalized BAEs. The results showed that D (diameter at breast height) was a better independent variable in estimating the biomass of branch, leaf, root, aboveground section and total tree than a combined variable (D2 H) of D and H (tree height) , but D2H was better than D in estimating stem biomass. R2 (coefficient of determination) values of BAEs for 6 species decreased when adding H as the second independent variable into D- only BAEs, where R2 value for S. sinensis decreased by 5.6%. Compared with generalized D- and D2H-based BAEs, standard errors of estimate (SEE) of BAEs for 8 tree species decreased, and similar decreasing trend was observed for different components, where SEEs of the branch decreased by 13.0% and 20.3%. Therefore, the biomass carbon storage and its dynamic estimates were influenced largely by tree species and model types. In order to improve the accuracy of the estimates of biomass and carbon, we should consider the differences in tree species and model types.

  9. Water relations of evergreen and drought-deciduous trees along a seasonally dry tropical forest chronosequence

    PubMed Central

    Allen, Michael F.; Santiago, Louis S.

    2010-01-01

    Seasonally dry tropical forests (SDTF) are characterized by pronounced seasonality in rainfall, and as a result trees in these forests must endure seasonal variation in soil water availability. Furthermore, SDTF on the northern Yucatan Peninsula, Mexico, have a legacy of disturbances, thereby creating a patchy mosaic of different seral stages undergoing secondary succession. We examined the water status of six canopy tree species, representing contrasting leaf phenology (evergreen vs. drought-deciduous) at three seral stages along a fire chronosequence in order to better understand strategies that trees use to overcome seasonal water limitations. The early-seral forest was characterized by high soil water evaporation and low soil moisture, and consequently early-seral trees exhibited lower midday bulk leaf water potentials (ΨL) relative to late-seral trees (−1.01 ± 0.14 and −0.54 ± 0.07 MPa, respectively). Although ΨL did not differ between evergreen and drought-deciduous trees, results from stable isotope analyses indicated different strategies to overcome seasonal water limitations. Differences were especially pronounced in the early-seral stage where evergreen trees had significantly lower xylem water δ18O values relative to drought-deciduous trees (−2.6 ± 0.5 and 0.3 ± 0.6‰, respectively), indicating evergreen species used deeper sources of water. In contrast, drought-deciduous trees showed greater enrichment of foliar 18O (∆18Ol) and 13C, suggesting lower stomatal conductance and greater water-use efficiency. Thus, the rapid development of deep roots appears to be an important strategy enabling evergreen species to overcome seasonal water limitation, whereas, in addition to losing a portion of their leaves, drought-deciduous trees minimize water loss from remaining leaves during the dry season. PMID:20658152

  10. Water relations of evergreen and drought-deciduous trees along a seasonally dry tropical forest chronosequence.

    PubMed

    Hasselquist, Niles J; Allen, Michael F; Santiago, Louis S

    2010-12-01

    Seasonally dry tropical forests (SDTF) are characterized by pronounced seasonality in rainfall, and as a result trees in these forests must endure seasonal variation in soil water availability. Furthermore, SDTF on the northern Yucatan Peninsula, Mexico, have a legacy of disturbances, thereby creating a patchy mosaic of different seral stages undergoing secondary succession. We examined the water status of six canopy tree species, representing contrasting leaf phenology (evergreen vs. drought-deciduous) at three seral stages along a fire chronosequence in order to better understand strategies that trees use to overcome seasonal water limitations. The early-seral forest was characterized by high soil water evaporation and low soil moisture, and consequently early-seral trees exhibited lower midday bulk leaf water potentials (Ψ(L)) relative to late-seral trees (-1.01 ± 0.14 and -0.54 ± 0.07 MPa, respectively). Although Ψ(L) did not differ between evergreen and drought-deciduous trees, results from stable isotope analyses indicated different strategies to overcome seasonal water limitations. Differences were especially pronounced in the early-seral stage where evergreen trees had significantly lower xylem water δ(18)O values relative to drought-deciduous trees (-2.6 ± 0.5 and 0.3 ± 0.6‰, respectively), indicating evergreen species used deeper sources of water. In contrast, drought-deciduous trees showed greater enrichment of foliar (18)O (∆(18)O(l)) and (13)C, suggesting lower stomatal conductance and greater water-use efficiency. Thus, the rapid development of deep roots appears to be an important strategy enabling evergreen species to overcome seasonal water limitation, whereas, in addition to losing a portion of their leaves, drought-deciduous trees minimize water loss from remaining leaves during the dry season.

  11. Leaf ontogeny and demography explain photosynthetic seasonality in Amazon evergreen forests

    NASA Astrophysics Data System (ADS)

    Wu, J.; Albert, L.; Lopes, A. P.; Restrepo-Coupe, N.; Hayek, M.; Wiedemann, K. T.; Guan, K.; Stark, S. C.; Prohaska, N.; Tavares, J. V.; Marostica, S. F.; Kobayashi, H.; Ferreira, M. L.; Campos, K.; Silva, R. D.; Brando, P. M.; Dye, D. G.; Huxman, T. E.; Huete, A. R.; Nelson, B. W.; Saleska, S. R.

    2015-12-01

    Photosynthetic seasonality couples the evolutionary ecology of plant leaves to large-scale rhythms of carbon and water exchanges that are important feedbacks to climate. However, the extent, magnitude, and controls on photosynthetic seasonality of carbon-rich tropical forests are poorly resolved, controversial in the remote sensing literature, and inadequately represented in most earth system models. Here we show that ecosystem-scale phenology (measured by photosynthetic capacity), rather than environmental seasonality, is the primary driver of photosynthetic seasonality at four Amazon evergreen forests spanning gradients in rainfall seasonality, forest composition, and flux seasonality. We further demonstrate that leaf ontogeny and demography explain most of this ecosystem phenology at two central Amazon evergreen forests, using a simple leaf-cohort canopy model that integrates eddy covariance-derived CO2 fluxes, novel near-surface camera-detected leaf phenology, and ground observations of litterfall and leaf physiology. The coordination of new leaf growth and old leaf divestment (litterfall) during the dry season shifts canopy composition towards younger leaves with higher photosynthetic efficiency, driving large seasonal increases (~27%) in ecosystem photosynthetic capacity. Leaf ontogeny and demography thus reconciles disparate observations of forest seasonality from leaves to eddy flux towers to satellites. Strategic incorporation of such whole-plant coordination processes as phenology and ontogeny will improve ecological, evolutionary and earth system theories describing tropical forests structure and function, allowing more accurate representation of forest dynamics and feedbacks to climate in earth system models.

  12. Green Mansions: The Evergreen Forests of the Pacific Northwest.

    ERIC Educational Resources Information Center

    Philipek, Frances; Smith, Shelley; Brook, Richard

    2000-01-01

    Explores the ecosystem in Pacific Northwest Coastal America and investigates land management issues. Discusses the impact of canopy trees on temperature and the forest itself. Explains fungi's relationship with trees and presents activities on stream flow, wood, volcanoes, and plants for the classroom. (YDS)

  13. Green Mansions: The Evergreen Forests of the Pacific Northwest.

    ERIC Educational Resources Information Center

    Philipek, Frances; Smith, Shelley; Brook, Richard

    2000-01-01

    Explores the ecosystem in Pacific Northwest Coastal America and investigates land management issues. Discusses the impact of canopy trees on temperature and the forest itself. Explains fungi's relationship with trees and presents activities on stream flow, wood, volcanoes, and plants for the classroom. (YDS)

  14. Resource partitioning by evergreen and deciduous species in a tropical dry forest.

    PubMed

    Álvarez-Yépiz, Juan C; Búrquez, Alberto; Martínez-Yrízar, Angelina; Teece, Mark; Yépez, Enrico A; Dovciak, Martin

    2017-02-01

    Niche differentiation can lead to coexistence of plant species by partitioning limiting resources. Light partitioning promotes niche differentiation in tropical humid forests, but it is unclear how niche partitioning occurs in tropical dry forests where both light and soil resources can be limiting. We studied the adult niche of four dominant evergreen (cycad, palm) and drought-deciduous (legume, oak) species co-occurring along environmental gradients. We analyzed light intensity and soil fertility effects on key functional traits related to plant carbon and water economy, how these traits determine species' functional strategies, and how these strategies relate to relative species abundance and spatial patterns. Light intensity was negatively associated with a key trait linked to plant water economy (leaf δ (13) C, a proxy for long-term water-use efficiency-WUE), while soil fertility was negatively associated with a key trait for plant carbon economy (LNC, leaf nitrogen content). Evergreens were highly sclerophyllous and displayed an efficient water economy but poor carbon economy, in agreement with a conservative resource-use strategy (i.e., high WUE but low LNC, photosynthetic rates and stature). Conversely, deciduous species, with an efficient carbon economy but poor water economy, exhibited an exploitative resource-use strategy (i.e., high LNC, photosynthetic rates and stature, but low WUE). Evergreen and deciduous species segregated spatially, particularly at fine-scales, as expected for species with different resource-use strategies. The efficient water economy of evergreens was related to their higher relative abundance, suggesting a functional advantage against drought-deciduous species in water-limited environments within seasonally dry tropical forests.

  15. Deciduous and Evergreen Trees Rely on Deep Water Throughout the Year in a Subtropical Seasonal Forest

    NASA Astrophysics Data System (ADS)

    Ellsworth, P.

    2010-12-01

    In subtropical and tropical seasonal forests, trees have adapted to low shallow soil water availability during the dry season by modifying root density, rooting depth, and leaf phenology. Here we test the well known hypothesis that water uptake in deciduous trees is restricted to the shallow soil layer, which prevents them from sustaining transpiring leaves during the dry season. Evergreens, on the other hand, access perennially available deep water sources, allowing them to maintain their transpiring leaves during the dry season. To determine where in the soil profile deciduous and evergreen trees take up water, we used stable isotope analysis to measure water source use of two deciduous and three evergreen species for a period of 13 months. In addition, to test the possibility that leaflessness could alter the isotopic composition of stem water, we measured the isotopic variation in stem water caused by artificial defoliation of an evergreen species. Deciduous and evergreen trees took up water from the same depths in both the wet and dry seasons. Deciduous and evergreen trees used approximately 51% deep water (50-150cm) throughout the year, while soil from 0-20cm was the least important water source with 24 and 6% of water uptake for wet and dry seasons, respectively. Low use of shallow water (0-20cm) in the wet season was due to inconstant water availability. Though the top 20cm of soil is the location of most nutrients, the soil’s limited water availability requires plants to have access to a more reliable deep water source to meet both their dry and wet season transpirational demands. This apparent spatial uncoupling in water and nutrient uptake denotes separate resource allocation for nutrient and water acquisition. Deciduous trees showed isotopic enrichment of stem water compared to evergreen plants only during the period that deciduous trees were leafless. We explain this as isotopic enrichment of fixed pool of stem water by evaporation as our defoliation

  16. 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.

  17. Seasonal leaf dynamics for tropical evergreen forests in a process-based global ecosystem model

    NASA Astrophysics Data System (ADS)

    De Weirdt, M.; Verbeeck, H.; Maignan, F.; Peylin, P.; Poulter, B.; Bonal, D.; Ciais, P.; Steppe, K.

    2012-09-01

    The influence of seasonal phenology on canopy photosynthesis in tropical evergreen forests remains poorly understood, and its representation in global ecosystem models is highly simplified, typically with no seasonal variation of canopy leaf properties taken into account. Including seasonal variation in leaf age and photosynthetic capacity could improve the correspondence of global vegetation model outputs with the wet-dry season CO2 patterns measured at flux tower sites in these forests. We introduced a leaf litterfall dynamics scheme in the global terrestrial ecosystem model ORCHIDEE based on seasonal variations in net primary production (NPP), resulting in higher leaf turnover in periods of high productivity. The modifications in the leaf litterfall scheme induce seasonal variation in leaf age distribution and photosynthetic capacity. We evaluated the results of the modification against seasonal patterns of three long-term in-situ leaf litterfall datasets of evergreen tropical forests in Panama, French Guiana and Brazil. In addition, we evaluated the impact of the model improvements on simulated latent heat (LE) and gross primary productivity (GPP) fluxes for the flux tower sites Guyaflux (French Guiana) and Tapajós (km 67, Brazil). The results show that the introduced seasonal leaf litterfall corresponds well with field inventory leaf litter data and times with its seasonality. Although the simulated litterfall improved substantially by the model modifications, the impact on the modelled fluxes remained limited. The seasonal pattern of GPP improved clearly for the Guyaflux site, but no significant improvement was obtained for the Tapajós site. The seasonal pattern of the modelled latent heat fluxes was hardly changed and remained consistent with the observed fluxes. We conclude that we introduced a realistic and generic litterfall dynamics scheme, but that other processes need to be improved in the model to achieve better simulations of GPP seasonal patterns

  18. Protected Areas: Mixed Success in Conserving East Africa’s Evergreen Forests

    PubMed Central

    Pfeifer, Marion; Burgess, Neil D.; Swetnam, Ruth D.; Platts, Philip J.; Willcock, Simon; Marchant, Robert

    2012-01-01

    In East Africa, human population growth and demands for natural resources cause forest loss contributing to increased carbon emissions and reduced biodiversity. Protected Areas (PAs) are intended to conserve habitats and species. Variability in PA effectiveness and ‘leakage’ (here defined as displacement of deforestation) may lead to different trends in forest loss within, and adjacent to, existing PAs. Here, we quantify spatial variation in trends of evergreen forest coverage in East Africa between 2001 and 2009, and test for correlations with forest accessibility and environmental drivers. We investigate PA effectiveness at local, landscape and national scales, comparing rates of deforestation within park boundaries with those detected in park buffer zones and in unprotected land more generally. Background forest loss (BFL) was estimated at −9.3% (17,167 km2), but varied between countries (range: −0.9% to −85.7%; note: no BFL in South Sudan). We document high variability in PA effectiveness within and between PA categories. The most successful PAs were National Parks, although only 26 out of 48 parks increased or maintained their forest area (i.e. Effective parks). Forest Reserves (Ineffective parks, i.e. parks that lose forest from within boundaries: 204 out of 337), Nature Reserves (six out of 12) and Game Parks (24 out of 26) were more likely to lose forest cover. Forest loss in buffer zones around PAs exceeded background forest loss, in some areas indicating leakage driven by Effective National Parks. Human pressure, forest accessibility, protection status, distance to fires and long-term annual rainfall were highly significant drivers of forest loss in East Africa. Some of these factors can be addressed by adjusting park management. However, addressing close links between livelihoods, natural capital and poverty remains a fundamental challenge in East Africa’s forest conservation efforts. PMID:22768074

  19. Interannual variation of carbon fluxes from three contrasting evergreen forests: the role of forest dynamics and climate.

    PubMed

    Sierra, Carlos A; Loescher, Henry W; Harmon, Mark E; Richardson, Andrew D; Hollinger, David Y; Perakis, Steven S

    2009-10-01

    Interannual variation of carbon fluxes can be attributed to a number of biotic and abiotic controls that operate at different spatial and temporal scales. Type and frequency of disturbance, forest dynamics, and climate regimes are important sources of variability. Assessing the variability of carbon fluxes from these specific sources can enhance the interpretation of past and current observations. Being able to separate the variability caused by forest dynamics from that induced by climate will also give us the ability to determine if the current observed carbon fluxes are within an expected range or whether the ecosystem is undergoing unexpected change. Sources of interannual variation in ecosystem carbon fluxes from three evergreen ecosystems, a tropical, a temperate coniferous, and a boreal forest, were explored using the simulation model STANDCARB. We identified key processes that introduced variation in annual fluxes, but their relative importance differed among the ecosystems studied. In the tropical site, intrinsic forest dynamics contributed approximately 30% of the total variation in annual carbon fluxes. In the temperate and boreal sites, where many forest processes occur over longer temporal scales than those at the tropical site, climate controlled more of the variation among annual fluxes. These results suggest that climate-related variability affects the rates of carbon exchange differently among sites. Simulations in which temperature, precipitation, and radiation varied from year to year (based on historical records of climate variation) had less net carbon stores than simulations in which these variables were held constant (based on historical records of monthly average climate), a result caused by the functional relationship between temperature and respiration. This suggests that, under a more variable temperature regime, large respiratory pulses may become more frequent and high enough to cause a reduction in ecosystem carbon stores. Our results

  20. Interannual variation of carbon fluxes from three contrasting evergreen forests: The role of forest dynamics and climate

    USGS Publications Warehouse

    Sierra, C.A.; Loescher, H.W.; Harmon, M.E.; Richardson, A.D.; Hollinger, D.Y.; Perakis, S.S.

    2009-01-01

    Interannual variation of carbon fluxes can be attributed to a number of biotic and abiotic controls that operate at different spatial and temporal scales. Type and frequency of disturbance, forest dynamics, and climate regimes are important sources of variability. Assessing the variability of carbon fluxes from these specific sources can enhance the interpretation of past and current observations. Being able to separate the variability caused by forest dynamics from that induced by climate will also give us the ability to determine if the current observed carbon fluxes are within an expected range or whether the ecosystem is undergoing unexpected change. Sources of interannual variation in ecosystem carbon fluxes from three evergreen ecosystems, a tropical, a temperate coniferous, and a boreal forest, were explored using the simulation model STANDCARB. We identified key processes that introduced variation in annual fluxes, but their relative importance differed among the ecosystems studied. In the tropical site, intrinsic forest dynamics contributed ?? 30% of the total variation in annual carbon fluxes. In the temperate and boreal sites, where many forest processes occur over longer temporal scales than those at the tropical site, climate controlled more of the variation among annual fluxes. These results suggest that climate-related variability affects the rates of carbon exchange differently among sites. Simulations in which temperature, precipitation, and radiation varied from year to year (based on historical records of climate variation) had less net carbon stores than simulations in which these variables were held constant (based on historical records of monthly average climate), a result caused by the functional relationship between temperature and respiration. This suggests that, under a more variable temperature regime, large respiratory pulses may become more frequent and high enough to cause a reduction in ecosystem carbon stores. Our results also show

  1. Contrasting seasonal leaf habits of canopy trees between tropical dry-deciduous and evergreen forests in Thailand.

    PubMed

    Ishida, Atsushi; Diloksumpun, Sapit; Ladpala, Phanumard; Staporn, Duriya; Panuthai, Samreong; Gamo, Minoru; Yazaki, Kenichi; Ishizuka, Moriyoshi; Puangchit, Ladawan

    2006-05-01

    We compared differences in leaf properties, leaf gas exchange and photochemical properties between drought-deciduous and evergreen trees in tropical dry forests, where soil nutrients differed but rainfall was similar. Three canopy trees (Shorea siamensis Miq., Xylia xylocarpa (Roxb.) W. Theob. and Vitex peduncularis Wall. ex Schauer) in a drought-deciduous forest and a canopy tree (Hopea ferrea Lanessan) in an evergreen forest were selected. Soil nutrient availability is lower in the evergreen forest than in the deciduous forest. Compared with the evergreen tree, the deciduous trees had shorter leaf life spans, lower leaf masses per area, higher leaf mass-based nitrogen (N) contents, higher leaf mass-based photosynthetic rates (mass-based P(n)), higher leaf N-based P(n), higher daily maximum stomatal conductance (g(s)) and wider conduits in wood xylem. Mass-based P(n) decreased from the wet to the dry season for all species. Following onset of the dry season, daily maximum g(s) and sensitivity of g(s) to leaf-to-air vapor pressure deficit remained relatively unchanged in the deciduous trees, whereas both properties decreased in the evergreen tree during the dry season. Photochemical capacity and non-photochemical quenching (NPQ) of photosystem II (PSII) also remained relatively unchanged in the deciduous trees even after the onset of the dry season. In contrast, photochemical capacity decreased and NPQ increased in the evergreen tree during the dry season, indicating that the leaves coped with prolonged drought by down-regulating PSII. Thus, the drought-avoidant deciduous species were characterized by high N allocation for leaf carbon assimilation, high water use and photoinhibition avoidance, whereas the drought-tolerant evergreen was characterized by low N allocation for leaf carbon assimilation, conservative water use and photoinhibition tolerance.

  2. Leaf development and demography explain photosynthetic seasonality in Amazon evergreen forests

    USGS Publications Warehouse

    Wu, Jin; Albert, Lauren; Lopes, Aline; Restrepo-Coupe, Natalia; Hayek, Matthew; Wiedemann, Kenia T.; Guan, Kaiyu; Stark, Scott C.; Christoffersen, Bradley; Prohaska, Neill; Tavares, Julia V.; Marostica, Suelen; Kobayashi, Hideki; Ferreira, Maurocio L.; Campos, Kleber Silva; da Silva, Rodrigo; Brando, Paulo M.; Dye, Dennis G.; Huxman, Travis E.; Huete, Alfredo; Nelson, Bruce; Saleska, Scott

    2016-01-01

    In evergreen tropical forests, the extent, magnitude, and controls on photosynthetic seasonality are poorly resolved and inadequately represented in Earth system models. Combining camera observations with ecosystem carbon dioxide fluxes at forests across rainfall gradients in Amazônia, we show that aggregate canopy phenology, not seasonality of climate drivers, is the primary cause of photosynthetic seasonality in these forests. Specifically, synchronization of new leaf growth with dry season litterfall shifts canopy composition toward younger, more light-use efficient leaves, explaining large seasonal increases (~27%) in ecosystem photosynthesis. Coordinated leaf development and demography thus reconcile seemingly disparate observations at different scales and indicate that accounting for leaf-level phenology is critical for accurately simulating ecosystem-scale responses to climate change.

  3. Leaf development and demography explain photosynthetic seasonality in Amazon evergreen forests.

    PubMed

    Wu, Jin; Albert, Loren P; Lopes, Aline P; Restrepo-Coupe, Natalia; Hayek, Matthew; Wiedemann, Kenia T; Guan, Kaiyu; Stark, Scott C; Christoffersen, Bradley; Prohaska, Neill; Tavares, Julia V; Marostica, Suelen; Kobayashi, Hideki; Ferreira, Mauricio L; Campos, Kleber Silva; da Silva, Rodrigo; Brando, Paulo M; Dye, Dennis G; Huxman, Travis E; Huete, Alfredo R; Nelson, Bruce W; Saleska, Scott R

    2016-02-26

    In evergreen tropical forests, the extent, magnitude, and controls on photosynthetic seasonality are poorly resolved and inadequately represented in Earth system models. Combining camera observations with ecosystem carbon dioxide fluxes at forests across rainfall gradients in Amazônia, we show that aggregate canopy phenology, not seasonality of climate drivers, is the primary cause of photosynthetic seasonality in these forests. Specifically, synchronization of new leaf growth with dry season litterfall shifts canopy composition toward younger, more light-use efficient leaves, explaining large seasonal increases (~27%) in ecosystem photosynthesis. Coordinated leaf development and demography thus reconcile seemingly disparate observations at different scales and indicate that accounting for leaf-level phenology is critical for accurately simulating ecosystem-scale responses to climate change. Copyright © 2016, American Association for the Advancement of Science.

  4. From leaf longevity to canopy seasonality: a carbon optimality phenology model for tropical evergreen forests

    NASA Astrophysics Data System (ADS)

    Xu, X.; Medvigy, D.; Wu, J.; Wright, S. J.; Kitajima, K.; Pacala, S. W.

    2016-12-01

    Tropical evergreen forests play a key role in the global carbon, water and energy cycles. Despite apparent evergreenness, this biome shows strong seasonality in leaf litter and photosynthesis. Recent studies have suggested that this seasonality is not directly related to environmental variability but is dominated by seasonal changes of leaf development and senescence. Meanwhile, current terrestrial biosphere models (TBMs) can not capture this pattern because leaf life cycle is highly underrepresented. One challenge to model this leaf life cycle is the remarkable diversity in leaf longevity, ranging from several weeks to multiple years. Ecologists have proposed models where leaf longevity is regarded as a strategy to optimize carbon gain. However previous optimality models can not be readily integrated into TBMs because (i) there are still large biases in predicted leaf longevity and (ii) it is never tested whether the carbon optimality model can capture the observed seasonality in leaf demography and canopy photosynthesis. In this study, we develop a new carbon optimality model for leaf demography. The novelty of our approach is two-fold. First, we incorporate a mechanistic photosynthesis model that can better estimate leaf carbon gain. Second, we consider the interspecific variations in leaf senescence rate, which strongly influence the modelled optimal carbon gain. We test our model with a leaf trait database for Panamanian evergreen forests. Then, we apply the model at seasonal scale and compare simulated seasonality of leaf litter and canopy photosynthesis with in-situ observations from several Amazonian forest sites. We find that (i) compared with original optimality model, the regression slope between observed and predicted leaf longevity increases from 0.15 to 1.04 in our new model and (ii) that our new model can capture the observed seasonal variations of leaf demography and canopy photosynthesis. Our results suggest that the phenology in tropical evergreen

  5. Distribution and dynamics of the evergreen understory layer in central Appalachian highland forests

    NASA Astrophysics Data System (ADS)

    Chastain, Robert A., Jr.

    Evergreen understory layer communities dominated by Rhododendron maximum L. and/or Kalmia latifolia L. may exert significant controls on regeneration of overstory trees, carbon sequestration, and nutrient retention in central Appalachian forests, but their distribution and ecological importance are poorly understood at the regional scale. The distribution, temporal dynamics, and biomass of the evergreen understory layer were examined in the Ridge and Valley and Allegheny Plateau physiographic provinces in the mid-Atlantic Highlands using plot data, remote sensing, dendrochronology, and modeling. First, leaf-off satellite remote sensing and topographic data were applied to map the spatial extent and distribution of R. maximum and K. latifolia with better than 80 percent accuracy. Second, plot data were used to determine the relevant environmental factors and species associations related to the distributions of K. latifolia and R. maximum and assess their influence on forest vertical structure. Cluster analysis and ordination revealed that topo-edaphic gradients and intensity of gypsy moth defoliation were associated with differences in the distribution of these two shrub species within and between the two study areas, and midstory volume was significantly lower where evergreen understory coverage was continuous. Third, variation in K. latifolia and R. maximum growth rates were examined using remote sensing change detection and dendrochronology, and trends were compared to the timing of climatic fluctuations and gypsy moth defoliation of canopy trees. Remote sensing showed that patterns of evergreen understory growth vigor correlated with both defoliation and topographically mediated drought stress. Dendrochronology revealed considerable within-site variability among individual shrubs. However, both releases and suppressions in growth were associated with the timing of gypsy moth defoliation for K. latifolia in both provinces and for R. maximum in the Allegheny

  6. An analysis of the decadal variability of Carbon fluxes in three evergreen European forests through modelling

    NASA Astrophysics Data System (ADS)

    Delpierre, N.; Dufrêne, E.

    2009-04-01

    With several sites measuring mass and energy turbulent fluxes for more than ten years, the CarboEurope database appears as a valuable resource for addressing the question of the determinism of the interannual variability of carbon (C) and water balances in forests ecosystems. Apart from major climate-driven anomalies during the anomalous 2003 summer and 2007 spring, little is known about the factors driving interannual variability (IAV) of the C balance in forest ecosystems. We used the CASTANEA process-based model to simulate the C and W fluxes and balances of three European evergreen forests for the 2000-2007 period (FRPue Quercus ilex, 44°N; DETha Picea abies, 51°N; FIHyy Pinus sylvestris, 62°N). The model fairly reproduced the day-to-day variability of measured fluxes, accounting for 70-81%, 77-91% and 59-90% of the daily variance of measured NEP, GPP and TER, respectively. However, the model was challenged in representing the IAV of fluxes integrated on an annual time scale. It reproduced ca. 80% of the interannual variance of measured GPP, but no significant relationship could be established between annual measured and modelled NEP or TER. Accordingly, CASTANEA appeared as a suitable tool for disentangling the influence of climate and biological processes on GPP at mutiple time scales. We show that climate and biological processes relative influences on the modelled GPP vary from year to year in European evergreen forests. Water-stress related and phenological processes (i.e. release of the winter thermal constraint on photosynthesis in evergreens) appear as primary drivers for the particular 2003 and 2007 years, respectively, but the relative influence of other climatic factors widely varies for less remarkable years at all sites. We discuss shortcomings of the method, as related to the influence of compensating errors in the simulated fluxes, and assess the causes of the model poor ability to represent the IAV of the annual sums of NEP and TER.

  7. [Dynamic Characteristics of Base Cations During Wet Deposition in Evergreen Broad-leaf Forest Ecosystem].

    PubMed

    An, Si-wei; Sun, Tao; Ma, Ming; Wang, Ding-yong

    2015-12-01

    Based on field tests and laboratory experiments, effects of precipitation, throughfall, litterfall, and groundwater runoff of the ever-green broad-leaf forest on the dynamic characteristics of base cations in Simian Mountain were investigated from September 2012 to August 2013. The results showed that the rainfall of Simian Mountain was apparently acidic, with average pH of 4.90 and maximum pH of 5.14. The soil and canopies could increase pH of precipitation, with soils having the maximum increment, followed by the forest canopy. Forest canopy only had the function of interception on Na⁺. And precipitation could leach out Ca2⁺, Mg2⁺ and K⁺ of the canopies. Moreover, the degradation of litter was probably the main reason for the increase of base cations concentrations in the surface litter water. The litter water leached Ca2⁺, Mg2⁺ and Na⁺ of the forest soil through downward infiltration. The total retention rates of Ca²⁺, Mg²⁺, Na⁺ and K⁺ were 33.82%, -7.06%, 74.36% and 42.87%, respectively. Ca²⁺, Na⁺, K⁺ were found to be reserved in the forest ecosystem, and the highest interception rate was found for Na⁺.

  8. Effects of forest age on soil autotrophic and heterotrophic respiration differ between evergreen and deciduous forests.

    PubMed

    Wang, Wei; Zeng, Wenjing; Chen, Weile; Yang, Yuanhe; Zeng, Hui

    2013-01-01

    We examined the effects of forest stand age on soil respiration (SR) including the heterotrophic respiration (HR) and autotrophic respiration (AR) of two forest types. We measured soil respiration and partitioned the HR and AR components across three age classes ~15, ~25, and ~35-year-old Pinus sylvestris var. mongolica (Mongolia pine) and Larix principis-rupprechtii (larch) in a forest-steppe ecotone, northern China (June 2006 to October 2009). We analyzed the relationship between seasonal dynamics of SR, HR, AR and soil temperature (ST), soil water content (SWC) and normalized difference vegetation index (NDVI, a plant greenness and net primary productivity indicator). Our results showed that ST and SWC were driving factors for the seasonal dynamics of SR rather than plant greenness, irrespective of stand age and forest type. For ~15-year-old stands, the seasonal dynamics of both AR and HR were dependent on ST. Higher Q10 of HR compared with AR occurred in larch. However, in Mongolia pine a similar Q10 occurred between HR and AR. With stand age, Q10 of both HR and AR increased in larch. For Mongolia pine, Q10 of HR increased with stand age, but AR showed no significant relationship with ST. As stand age increased, HR was correlated with SWC in Mongolia pine, but for larch AR correlated with SWC. The dependence of AR on NDVI occurred in ~35-year-old Mongolia pine. Our study demonstrated the importance of separating autotrophic and heterotrophic respiration components of SR when stimulating the response of soil carbon efflux to environmental changes. When estimating the response of autotrophic and heterotrophic respiration to environmental changes, the effect of forest type on age-related trends is required.

  9. Constructing seasonal LAI trajectory by data-model fusion for global evergreen needle-leaf forests

    NASA Astrophysics Data System (ADS)

    Wang, R.; Chen, J.; Mo, G.

    2010-12-01

    For decades, advancements in optical remote sensors made it possible to produce maps of a biophysical parameter--the Leaf Area Index (LAI), which is critically necessary in regional and global modeling of exchanges of carbon, water, energy and other substances, across large areas in a fast way. Quite a few global LAI products have been generated since 2000, e.g. GLOBCARBON (Deng et al., 2006), MODIS Collection 5 (Shabanov et al., 2007), CYCLOPES (Baret et al., 2007), etc. Albeit these progresses, the basic physics behind the technology restrains it from accurate estimation of LAI in winter, especially for northern high-latitude evergreen needle-leaf forests. Underestimation of winter LAI in these regions has been reported in literature (Yang et al., 2000; Cohen et al., 2003; Tian et al., 2004; Weiss et al., 2007; Pisek et al., 2007), and the distortion is usually attributed to the variations of canopy reflectance caused by understory change (Weiss et al., 2007) as well as by the presence of ice and snow on leaves and ground (Cohen, 2003; Tian et al., 2004). Seasonal changes in leaf pigments can also be another reason for low LAI retrieved in winter. Low conifer LAI values in winter retrieved from remote sensing make them unusable for surface energy budget calculations. To avoid these drawbacks of remote sensing approaches, we attempt to reconstruct the seasonal LAI trajectory through model-data fusion. A 1-degree LAI map of global evergreen needle-leaf forests at 10-day interval is produced based on the carbon allocation principle in trees. With net primary productivity (NPP) calculated by the Boreal Ecosystems Productivity Simulator (BEPS) (Chen et al., 1999), carbon allocated to needles is quantitatively evaluated and then can be further transformed into LAI using the specific leaf area (SLA). A leaf-fall scheme is developed to mimic the carbon loss caused by falling needles throughout the year. The seasonally maximum LAI from remote sensing data for each pixel

  10. Effect of urbanization on the structure and functional traits of remnant subtropical evergreen broad-leaved forests in South China

    Treesearch

    Liujing Huang; Hongfeng Chen; Hai Ren; Jun Wang; Qinfeng Guo

    2013-01-01

    We investigated the effects of major environmental drivers associated with urbanization on species diversity and plant functional traits (PFTs) in the remnant subtropical evergreen broad-leaved forests in Metropolitan Guangzhou (Guangdong, China). Twenty environmental factors including topography, light, and soil properties were used to quantify the effects of...

  11. Differential responses of carbon and water vapor fluxes to climate among evergreen needleleaf forests in the USA

    USDA-ARS?s Scientific Manuscript database

    Understanding of differences in carbon and water vapor fluxes of spatially distributed evergreen needle leaf forests (ENFs) is crucial to accurately estimating regional carbon and water budgets and when predicting the responses of ENFs to future climate. We investigated cross-site variability in car...

  12. Carbon limitation leads to suppression of first year oak seedlings beneath evergreen understory shrubs in Southern Appalachian hardwood forests

    Treesearch

    Colin M. Beier; Jonathan L. Horton; John F. Walker; Barton D. Clinton; Erik T. Nilsen

    2005-01-01

    Inhibition of canopy tree recruitment beneath thickets of the evergreen shrubs Rhododendron maximum L. and Kalmia latifolia L. has long been observed in South Appalachian forests, yet the mechanisms of this process remain unresolved. We present a first-year account of suppression of oak seedlings in relation to ...

  13. Genetic diversity and seed production in Santa Lucia fir (Abies bracteata),a relict of the Miocene broadleaved evergreen forest

    Treesearch

    F. Thomas Ledig; Paul D. Hodgskiss; David R. Johnson

    2006-01-01

    Santa Lucia fir (Abies bracteata), is a unique fir, the sole member of the subgenus Pseudotorreya. It is a relict of the Miocene broadleaved evergreen sclerophyll forest, and is now restricted to a highly fragmented range in the Santa Lucia Mountains of central coastal California. Expected heterozygosity for 30 isozyme loci in 18 enzyme systems...

  14. 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...

  15. Seasonal leaf dynamics for tropical evergreen forests in a process based global ecosystem model

    NASA Astrophysics Data System (ADS)

    de Weirdt, M.; Verbeeck, H.; Maignan, F.; Peylin, P.; Poulter, B.; Bonal, D.; Ciais, P.; Steppe, K.

    2012-02-01

    The influence of seasonal phenology in tropical humid forests on canopy photosynthesis remains poorly understood and its representation in global vegetation models highly simplified, typically with no seasonal variability of canopy leaf area properties taken into account. However, recent flux tower and remote sensing studies suggest that seasonal phenology in tropical rainforests exerts a large influence over carbon and water fluxes, with feedbacks that can significantly influence climate dynamics. A more realistic description of the underlying mechanisms that drive seasonal tropical forest photosynthesis and phenology could improve the correspondence of global vegetation model outputs with the wet-dry season biogeochemical patterns measured at flux tower sites. Here, we introduce a leaf Net Primary Production (NPP) based canopy dynamics scheme for evergreen tropical forests in the global terrestrial ecosystem model ORCHIDEE and validated the new scheme against in-situ carbon flux measurements. Modelled Gross Primary Productivity (GPP) patterns are analyzed in details for a flux tower site in French Guiana, in a forest where the dry season is short and where the vegetation is considered to have developed adaptive mechanisms against drought stress. By including leaf litterfall seasonality and a coincident light driven leaf flush and seasonal change in photosynthetic capacity in ORCHIDEE, modelled carbon and water fluxes more accurately represent the observations. The fit to GPP flux data was substantially improved and the results confirmed that by modifying canopy dynamics to benefit from increased light conditions, a better representation of the seasonal carbon flux patterns was made.

  16. Inter- and intra-specific variation in stemflow for evergreen species and deciduous tree species in a subtropical forest

    NASA Astrophysics Data System (ADS)

    Su, Lei; Xu, Wenting; Zhao, Changming; Xie, Zongqiang; Ju, Hua

    2016-06-01

    Quantification of stemflow is necessary for the assessment of forest ecosystem hydrological effects. Nevertheless, variation of stemflow among plant functional groups is currently not well understood. Stemflow production of co-occurring evergreen broadleaved trees (Cyclobalanopsis multinervis and Cyclobalanopsis oxyodon) and deciduous broadleaved trees (Fagus engleriana and Quercus serrata var. brevipetiolata) was quantified through field observations in a mixed evergreen and deciduous broadleaved forest. The research results revealed that stemflow increased linearly with increasing rainfall magnitude, with precipitation depths of 6.9, 7.2, 10.0 and 14.8 mm required for the initiation of stemflow for C. multinervis, C. oxyodon, F. engleriana and Q. serrata, respectively. Stemflow percentage and funneling ratio (FR) increased with increasing rainfall in a logarithmic fashion. Stemflow percentage and FR tended to grow rapidly with increasing rainfall magnitude up to a rainfall threshold of 50 mm, above which, further rainfall increases brought about only small increases. For C. multinervis, C. oxyodon, F. engleriana and Q. serrata, FR averaged 19.8, 14.8, 8.9 and 2.8, respectively. The stemflow generating rainfall thresholds for evergreen species were smaller than for deciduous species. Furthermore, stemflow percentage and FR of the former was greater than the latter. For both evergreen species and deciduous species, overall funneling ratio (FRs) decreased with increasing basal area. We concluded that: (1) although stemflow partitioning represented a fairly low percentage of gross rainfall in mixed evergreen and deciduous broadleaved forests, it was capable of providing substantial amount of rainwater to tree boles; (2) the evergreen species were more likely to generate stemflow than deciduous species, and directed more intercepted rainwater to the root zone; (3) small trees were more productive in funneling stemflow than larger trees, which may provide a favorable

  17. 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.

  18. Light-driven growth in Amazon evergreen forests explained by seasonal variations of vertical canopy structure.

    PubMed

    Tang, Hao; Dubayah, Ralph

    2017-03-07

    Light-regime variability is an important limiting factor constraining tree growth in tropical forests. However, there is considerable debate about whether radiation-induced green-up during the dry season is real, or an apparent artifact of the remote-sensing techniques used to infer seasonal changes in canopy leaf area. Direct and widespread observations of vertical canopy structures that drive radiation regimes have been largely absent. Here we analyze seasonal dynamic patterns between the canopy and understory layers in Amazon evergreen forests using observations of vertical canopy structure from a spaceborne lidar. We discovered that net leaf flushing of the canopy layer mainly occurs in early dry season, and is followed by net abscission in late dry season that coincides with increasing leaf area of the understory layer. Our observations of understory development from lidar either weakly respond to or are not correlated to seasonal variations in precipitation or insolation, but are strongly related to the seasonal structural dynamics of the canopy layer. We hypothesize that understory growth is driven by increased light gaps caused by seasonal variations of the canopy. This light-regime variability that exists in both spatial and temporal domains can better reveal the drought-induced green-up phenomenon, which appears less obvious when treating the Amazon forests as a whole.

  19. [Effects of Phyllostachys edulis expansion on soil nitrogen mineralization and its availability in evergreen broadleaf forest].

    PubMed

    Song, Qing-Ni; Yang, Qing-Pei; Liu, Jun; Yu, Ding-Kun; Fang, Kai; Xu, Pei; He, Yu-juan

    2013-02-01

    By the methods of space-time substitution and PVC tube closed-top in situ incubation, this paper studied the soil mineralized-N content, N mineralization rate, and N uptake rate in Phyllostachys edulis-broadleaf mixed forest (PBMF) formed by P. edulis expansion and its adjacent evergreen broadleaf forest (EBF) in Dagangshan Mountain of Jiangxi Province, China. There existed the same spatiotemporal variation trend of soil total mineralized-N (TMN) content between the two forests. The annual average N mineralization rate was slightly lower in PBMF than in EBF. In PBMF, soil N mineralization was dominated by ammonification; while in EBF, soil ammonification and nitrification were well-matched in rate, and soil nitrification was dominated in growth season (from April to October). The N uptake by the plants in PBMF and EBF in a year was mainly in the form of NH4+-N, but that in EBF in growth season was mainly in the form of NO3- -N. These findings indicated that the expansion of P. edulis into EBF could promote the ammonification of soil N, weakened soil nitrification and total N mineralization, and also, increased the NH4+-N uptake but decreased the NO3- -N and TMN uptake by the plants.

  20. Growing up with stress - carbon sequestration and allocation dynamics of a broadleaf evergreen forest

    NASA Astrophysics Data System (ADS)

    Griebel, Anne; Bennett, Lauren T.; Arndt, Stefan K.

    2016-04-01

    Evergreen forests have the potential to sequester carbon year-round due to the presence of leaves with a multi-year lifespan. Eucalypt forests occur in warmer climates where temperature and radiation are not imposing a strong seasonality. Thus, unlike deciduous or many coniferous trees, many eucalypts grow opportunistically as conditions allow. As such, many eucalypts do not produce distinct growth rings, which present challenges to the implementation of standard methods and data interpretation approaches for monitoring and explaining carbon allocation dynamics in response to climatic stress. As a consequence, there is a lack of detailed understanding of seasonal growth dynamics of evergreen forests as a whole, and, in particular, of the influence of climatic drivers on carbon allocation to the various biomass pools. We used a multi-instrument approach in a mixed species eucalypt forest to investigate the influence of climatic drivers on the seasonal growth dynamics of a predominantly temperate and moisture-regulated environment in south-eastern Australia. Ecosystem scale observations of net ecosystem exchange (NEE) from a flux tower in the Wombat forest near Melbourne indicated that the ecosystem is a year-round carbon sink, but that intra-annual variations in temperature and moisture along with prolonged heat waves and dry spells resulted in a wide range of annual sums over the past three years (NEE ranging from ~4 to 12 t C ha-1 yr-1). Dendrometers were used to monitor stem increments of the three dominant eucalypt species. Stem expansion was generally opportunistic with the greatest increments under warm but moist conditions (often in spring and autumn), and the strongest indicators of stem growth dynamics being radiation, vapour pressure deficit and a combined heat-moisture index. Differences in the seasonality of stem increments between species were largely due to differences in the canopy position of sampled individuals. The greatest stem increments were

  1. Environmental Drivers of Whole-Ecosystem Methane Fluxes from a Lowland Evergreen Forest

    NASA Astrophysics Data System (ADS)

    Shoemaker, J. K.; Keenan, T. F.; Hollinger, D. Y.; Richardson, A. D.

    2013-12-01

    Forests dominate the global carbon cycle, but their role in methane (CH4) biogeochemistry remains uncertain. Limitations in mesoscale sampling approaches has led to gaps in our knowledge of the dynamics of CH4 uptake and release from forested ecosystems and the environmental drivers that control these fluxes. Methane, a more potent greenhouse gas than carbon dioxide (CO2) over short timescales, may have an important role to play in determining the total climate influence of a forest system. Here we examine a time series of methane fluxes, obtained over 2 years by eddy flux covariance, from a lowland evergreen forest in central Maine, USA. During 2011, a wetter than average year, the forest was a net source of CH4 from the beginning of the measurement period in July through October. In 2012, a drier than average year, the forest was a small source only from early June through mid-July after which it transitioned to a weak sink for the remainder of the year. Using both a multiple linear regression and an artificial neural network approach, we find gross primary productivity (GPP, estimated from eddy covariance CO2 fluxes) to provide the strongest correlation with the seasonal trend in CH4 flux. While GPP alone provides the majority of the models' correlation during 2011, including soil moisture at 10cm significantly improves the fit of the model during 2012. Using a linear model of GPP and soil moisture, combined with Monte-Carlo resampling, we estimate that the total annual CH4 fluxes for 2011 and 2012 at Howland forest were 6900 +/- 4600 and -18000 +/- 2700 umol m-2 yr-1, respectively (means +/- 1sd). While these fluxes are very small compared to the annual CO2 consumption at this site (~300 g m-2 yr-1), these forest CH4 fluxes may contribute significantly to both short- and long-term variability in regional CH4 emissions. Understanding how environmental drivers influence CH4 fluxes at the landscape scale is critical to developing appropriate model structures for

  2. Climatic and biotic drivers of tropical evergreen forest photosynthesis: integrating field, eddy flux, remote sensing and modelling

    NASA Astrophysics Data System (ADS)

    Wu, J.; Serbin, S.; Xu, X.; Guan, K.; Albert, L.; Hayek, M.; Restrepo-Coupe, N.; Lopes, A. P.; Wiedemann, K. T.; Christoffersen, B. O.; Meng, R.; De Araujo, A. C.; Oliveira Junior, R. C.; Camargo, P. B. D.; Silva, R. D.; Nelson, B. W.; Huete, A. R.; Rogers, A.; Saleska, S. R.

    2016-12-01

    Tropical evergreen forest photosynthetic metabolism is an important driver of large-scale carbon, water, and energy cycles, generating various climate feedbacks. However, considerable uncertainties remain regarding how best to represent evergreen forest photosynthesis in current terrestrial biosphere models (TBMs), especially its sensitivity to climatic vs. biotic variation. Here, we develop a new approach to partition climatic and biotic controls on tropical forest photosynthesis from hourly to inter-annual timescales. Our results show that climatic factors dominate photosynthesis dynamics at shorter-time scale (i.e. hourly), while biotic factors dominate longer-timescale (i.e. monthly and longer) photosynthetic dynamics. Focusing on seasonal timescales, we combine camera and ecosystem carbon flux observations of forests across a rainfall gradient in Amazonia to show that high dry season leaf turnover shifts canopy composition towards younger more efficient leaves. This seasonal variation in leaf quality (per-area leaf photosynthetic capacity) thus can explain the high photosynthetic seasonality observed in the tropics. Finally, we evaluated the performance of models with different phenological schemes (i.e. leaf quantity versus leaf quality; with and without leaf phenological variation alone the vertical canopy profile). We found that models which represented the phenology of leaf quality and its within-canopy variation performed best in simulating photosynthetic seasonality in tropical evergreen forests. This work highlights the importance of incorporating improved understanding of climatic and biotic controls in next generation TBMs to project future carbon and water cycles in the tropics.

  3. Photoprotection of evergreen and drought-deciduous tree leaves to overcome the dry season in monsoonal tropical dry forests in Thailand.

    PubMed

    Ishida, Atsushi; Yamazaki, Jun-Ya; Harayama, Hisanori; Yazaki, Kenichi; Ladpala, Phanumard; Nakano, Takashi; Adachi, Minaco; Yoshimura, Kenichi; Panuthai, Samreong; Staporn, Duriya; Maeda, Takahisa; Maruta, Emiko; Diloksumpun, Sapit; Puangchit, Ladawan

    2014-01-01

    In tropical dry forests, uppermost-canopy leaves of evergreen trees possess the ability to use water more conservatively compared with drought-deciduous trees, which may result from significant differences in the photoprotective mechanisms between functional types. We examined the seasonal variations in leaf gas exchange, chlorophyll fluorescence and the amounts of photosynthetic pigments within lamina of the uppermost-canopy leaves of three drought-deciduous trees (Vitex peduncularis Wall., Xylia xylocarpa (Roxb.) W. Theob., Shorea siamensis Miq.), a semi-deciduous tree (Irvingia malayana Miq.) and two evergreen trees (Hopea ferrea Lanessan and Syzygium cumini (L.) Skeels) in Thailand. Area-based maximum carbon assimilation rates (Amax) decreased during the dry season, except in S. siamensis. The electron transport rate (ETR) remained unchanged in deciduous trees, but decreased during the dry season in evergreen and semi-deciduous trees. In the principal component analysis, the first axis (Axis 1) accounted for 44.3% of the total variation and distinguished deciduous from evergreen trees. Along Axis 1, evergreen trees were characterized by a high Stern-Volmer non-photochemical quenching coefficient (NPQ), high xanthophyll cycle pigments/chlorophyll and a high de-epoxidation state of the xanthophyll cycle, whereas the deciduous trees were characterized by a high ETR, a high quantum yield of PSII (ΦPSII = (Fm(') -F)/Fm(')) and a high mass-based Amax under high-light conditions. These findings indicate that drought-deciduous trees showing less conservative water use tend to dissipate a large proportion of electron flow through photosynthesis or alternative pathways. In contrast, the evergreens showed more conservative water use, reduced Amax and ETR and enhanced NPQ and xanthophyll cycle pigments/chlorophyll during the dry season, indicating that down-regulated photosynthesis with enhanced thermal dissipation of excess light energy played an important role in

  4. The rhizospheric microbial community structure and diversity of deciduous and evergreen forests in Taihu Lake area, China.

    PubMed

    Wei, Zhiwen; Hu, Xiaolong; Li, Xunhang; Zhang, Yanzhou; Jiang, Leichun; Li, Jing; Guan, Zhengbing; Cai, Yujie; Liao, Xiangru

    2017-01-01

    Soil bacteria are important drivers of biogeochemical cycles and participate in many nutrient transformations in the soil. Meanwhile, bacterial diversity and community composition are related to soil physic-chemical properties and vegetation factors. However, how the soil and vegetation factors affect the diversity and community composition of bacteria is poorly understood, especially for bacteria associated with evergreen and deciduous trees in subtropical forest ecosystems. In the present paper, the microbial communities of rhizospheric soils associated with different types of trees were analyzed by Illumina MiSeq sequencing the V3-V4 region of the 16S rRNA gene. A total of 121,219 effective 16S rRNA gene sequences were obtained, which were classified into 29 bacterial phyla and 2 archaeal phyla. The dominant phyla across all samples (>5% of good-quality sequences in each sample) were Proteobacteria, Acidobacteria, Firmicutes and Bacteroidetes. The bacterial community composition and diversity were largely affected by both soil pH and tree species. The soil pH was the key factor influencing bacterial diversity, with lower pH associated with less diverse communities. Meanwhile, the contents of NO3- were higher in evergreen tree soils than those associated with deciduous trees, while less NH4+ than those associated with deciduous trees, leading to a lower pH and indirectly influencing the diversity and composition of the bacteria. The co-occurrence patterns were assessed by network analysis. A total of 415 pairs of significant and robust correlations (co-occurrence and negative) were identified from 89 genera. Sixteen hubs of co-occurrence patterns, mainly under the phyla Acidobacteria, Proteobacteria, Firmicutes and Bacteroidetes, may play important roles in sustaining the stability of the rhizospheric microbial communities. In general, our results suggested that local environmental conditions and soil pH were important in shaping the bacterial community of the

  5. [Applicability analysis of spatially explicit model of leaf litter in evergreen broad-leaved forests].

    PubMed

    Zhao, Qing-Qing; Liu, He-Ming; Jonard, Mathieu; Wang, Zhang-Hua; Wang, Xi-Hua

    2014-11-01

    The spatially explicit model of leaf litter can help to understand its dispersal process, which is very important to predict the distribution pattern of leaves on the surface of the earth. In this paper, the spatially explicit model of leaf litter was developed for 20 tree species using litter trap data from the mapped forest plot in an evergreen broad-leaved forest in Tiantong, Zhejiang Pro- vince, eastern China. Applicability of the model was analyzed. The model assumed an allometric equation between diameter at breast height (DBH) and leaf litter amount, and the leaf litter declined exponentially with the distance. Model parameters were estimated by the maximum likelihood method. Results showed that the predicted and measured leaf litter amounts were significantly correlated, but the prediction accuracies varied widely for the different tree species, averaging at 49.3% and ranging from 16.0% and 74.0%. Model qualities of tree species significantly correlated with the standard deviations of the leaf litter amount per trap, DBH of the tree species and the average leaf dry mass of tree species. There were several ways to improve the forecast precision of the model, such as installing the litterfall traps according to the distribution of the tree to cover the different classes of the DBH and distance apart from the parent trees, determining the optimal dispersal function of each tree species, and optimizing the existing dispersal function.

  6. Effects of coffee management intensity on composition, structure, and regeneration status of ethiopian moist evergreen afromontane forests.

    PubMed

    Hundera, Kitessa; Aerts, Raf; Fontaine, Alexandre; Van Mechelen, Maarten; Gijbels, Pieter; Honnay, Olivier; Muys, Bart

    2013-03-01

    The effect of arabica coffee management intensity on composition, structure, and regeneration of moist evergreen Afromontane forests was studied in three traditional coffee-management systems of southwest Ethiopia: semiplantation coffee, semiforest coffee, and forest coffee. Vegetation and environmental data were collected in 84 plots from forests varying in intensity of coffee management. After controlling for environmental variation (altitude, aspect, slope, soil nutrient availability, and soil depth), differences in woody species composition, forest structure, and regeneration potential among management systems were compared using one way analysis of variance. The study showed that intensification of forest coffee cultivation to maximize coffee production negatively affects diversity and structure of Ethiopian moist evergreen Afromontane forests. Intensification of coffee productivity starts with the conversion of forest coffee to semiforest coffee, which has significant negative effects on tree seedling abundance. Further intensification leads to the conversion of semiforest to semiplantation coffee, causing significant diversity losses and the collapse of forest structure (decrease of stem density, basal area, crown closure, crown cover, and dominant tree height). Our study underlines the need for shade certification schemes to include variables other than canopy cover and that the loss of species diversity in intensively managed coffee systems may jeopardize the sustainability of coffee production itself through the decrease of ecosystem resilience and disruption of ecosystem services related to coffee yield, such as pollination and pest control.

  7. Effects of Coffee Management Intensity on Composition, Structure, and Regeneration Status of Ethiopian Moist Evergreen Afromontane Forests

    NASA Astrophysics Data System (ADS)

    Hundera, Kitessa; Aerts, Raf; Fontaine, Alexandre; Van Mechelen, Maarten; Gijbels, Pieter; Honnay, Olivier; Muys, Bart

    2013-03-01

    The effect of arabica coffee management intensity on composition, structure, and regeneration of moist evergreen Afromontane forests was studied in three traditional coffee-management systems of southwest Ethiopia: semiplantation coffee, semiforest coffee, and forest coffee. Vegetation and environmental data were collected in 84 plots from forests varying in intensity of coffee management. After controlling for environmental variation (altitude, aspect, slope, soil nutrient availability, and soil depth), differences in woody species composition, forest structure, and regeneration potential among management systems were compared using one way analysis of variance. The study showed that intensification of forest coffee cultivation to maximize coffee production negatively affects diversity and structure of Ethiopian moist evergreen Afromontane forests. Intensification of coffee productivity starts with the conversion of forest coffee to semiforest coffee, which has significant negative effects on tree seedling abundance. Further intensification leads to the conversion of semiforest to semiplantation coffee, causing significant diversity losses and the collapse of forest structure (decrease of stem density, basal area, crown closure, crown cover, and dominant tree height). Our study underlines the need for shade certification schemes to include variables other than canopy cover and that the loss of species diversity in intensively managed coffee systems may jeopardize the sustainability of coffee production itself through the decrease of ecosystem resilience and disruption of ecosystem services related to coffee yield, such as pollination and pest control.

  8. Genetic differentiation and genetic diversity of Castanopsis (Fagaceae), the dominant tree species in Japanese broadleaved evergreen forests, revealed by analysis of EST-associated microsatellites.

    PubMed

    Aoki, Kyoko; Ueno, Saneyoshi; Kamijo, Takashi; Setoguchi, Hiroaki; Murakami, Noriaki; Kato, Makoto; Tsumura, Yoshihiko

    2014-01-01

    The broadleaved evergreen forests of the East Asian warm temperate zone are characterised by their high biodiversity and endemism, and there is therefore a need to extend our understanding of its genetic diversity and phylogeographic patterns. Castanopsis (Fagaceae) is one of the dominant tree species in the broadleaved evergreen forests of Japan. In this study we investigate the genetic diversity, genetic structure and leaf epidermal morphology of 63 natural populations of C. sieboldii and C. cuspidata, using 32 Expressed Sequence Tag associated microsatellites. The overall genetic differentiation between populations was low (GST = 0.069 in C. sieboldii and GST = 0.057 in C. cuspidata). Neighbor-joining tree and Bayesian clustering analyses revealed that the populations of C. sieboldii and C. cuspidata were genetically clearly differentiated, a result which is consistent with the morphology of their epidermal cell layers. This suggests that C. sieboldii and C. cuspidata should be treated as independent species, although intermediate morphologies are often observed, especially at sites where the two species coexist. The higher level of genetic diversity observed in the Kyushu region (for both species) and the Ryukyu Islands (for C. sieboldii) is consistent with the available fossil pollen data for Castanopsis-type broadleaved evergreen trees during the Last Glacial Maximum and suggests the existence of refugia for Castanopsis forests in southern Japan. Within the C. sieboldii populations, Bayesian clustering analyses detected three clusters, in the western and eastern parts of the main islands and in the Ryukyu Islands. The west-east genetic differentiation observed for this species in the main islands, a pattern which is also found in several plant and animal species inhabiting Castanopsis forests in Japan, suggests that they have been isolated from each other in the western and eastern populations for an extended period of time, and may imply the

  9. Genetic Differentiation and Genetic Diversity of Castanopsis (Fagaceae), the Dominant Tree Species in Japanese Broadleaved Evergreen Forests, Revealed by Analysis of EST-Associated Microsatellites

    PubMed Central

    Aoki, Kyoko; Ueno, Saneyoshi; Kamijo, Takashi; Setoguchi, Hiroaki; Murakami, Noriaki; Kato, Makoto; Tsumura, Yoshihiko

    2014-01-01

    The broadleaved evergreen forests of the East Asian warm temperate zone are characterised by their high biodiversity and endemism, and there is therefore a need to extend our understanding of its genetic diversity and phylogeographic patterns. Castanopsis (Fagaceae) is one of the dominant tree species in the broadleaved evergreen forests of Japan. In this study we investigate the genetic diversity, genetic structure and leaf epidermal morphology of 63 natural populations of C. sieboldii and C. cuspidata, using 32 Expressed Sequence Tag associated microsatellites. The overall genetic differentiation between populations was low (GST = 0.069 in C. sieboldii and GST = 0.057 in C. cuspidata). Neighbor-joining tree and Bayesian clustering analyses revealed that the populations of C. sieboldii and C. cuspidata were genetically clearly differentiated, a result which is consistent with the morphology of their epidermal cell layers. This suggests that C. sieboldii and C. cuspidata should be treated as independent species, although intermediate morphologies are often observed, especially at sites where the two species coexist. The higher level of genetic diversity observed in the Kyushu region (for both species) and the Ryukyu Islands (for C. sieboldii) is consistent with the available fossil pollen data for Castanopsis-type broadleaved evergreen trees during the Last Glacial Maximum and suggests the existence of refugia for Castanopsis forests in southern Japan. Within the C. sieboldii populations, Bayesian clustering analyses detected three clusters, in the western and eastern parts of the main islands and in the Ryukyu Islands. The west-east genetic differentiation observed for this species in the main islands, a pattern which is also found in several plant and animal species inhabiting Castanopsis forests in Japan, suggests that they have been isolated from each other in the western and eastern populations for an extended period of time, and may imply the

  10. Phylogeography of Phytophagous Weevils and Plant Species in Broadleaved Evergreen Forests: A Congruent Genetic Gap between Western and Eastern Parts of Japan

    PubMed Central

    Aoki, Kyoko; Kato, Makoto; Murakami, Noriaki

    2011-01-01

    The Quaternary climate cycles played an important role in shaping the distribution of biodiversity among current populations, even in warm-temperate zones, where land was not covered by ice sheets. We focused on the Castanopsis-type broadleaved evergreen forest community in Japan, which characterizes the biodiversity and endemism of the warm-temperate zone. A comparison of the phylogeographic patterns of three types of phytophagous weevils associated with Castanopsis (a host-specific seed predator, a generalist seed predator, and a host-specific leaf miner) and several other plant species inhabiting the forests revealed largely congruent patterns of genetic differentiation between western and eastern parts of the main islands of Japan. A genetic gap was detected in the Kii Peninsula to Chugoku-Shikoku region, around the Seto Inland Sea. The patterns of western-eastern differentiation suggest past fragmentation of broadleaved evergreen forests into at least two separate refugia consisting of the southern parts of Kyushu to Shikoku and of Kii to Boso Peninsula. Moreover, the congruent phylogeographic patterns observed in Castanopsis and the phytophagous insect species imply that the plant-herbivore relationship has been largely maintained since the last glacial periods. These results reinforce the robustness of the deduced glacial and postglacial histories of Castanopsis-associated organisms. PMID:26467618

  11. [Spatial heterogeneity of soil organic carbon and total nitrogen in a monsoon evergreen broadleaf forest in Dinghushan, Guangdong, China].

    PubMed

    Zhang, Ya-Ru; Ouyang, Xu; Chu, Guo-Wei; Zhang, Qian-Mei; Liu, Shi-Zhong; Zhang, De-Qiang; Li, Yue-Lin

    2014-01-01

    Geostatistical techniques were used to quantify the spatial heterogeneity of soil organic carbon and total nitrogen of one monsoon evergreen broadleaf forest area in Dinghushan, Guangdong, China. The results demonstrated that a significant spatial autocorrelation existed between soil organic carbon and total nitrogen contents in the Dinghushan monsoon evergreen broadleaf forest, such that 93.6% and 53.7% of their total spatial heterogeneity originated from their spatial autocorrelation. This observation agreed with a traditional statistics analysis showing a significant linear correlation between soil organic carbon and total nitrogen, and also their spatial autocorrelation existed at a landscape level. The best fit from an exponential model showed that soil organic carbon had high degree of spatial heterogeneity at a scale of 17.4 m.

  12. Tree growth rates in an Amazonian evergreen forest: seasonal patterns and correlations with leaf phenology

    NASA Astrophysics Data System (ADS)

    Wu, J.; Silva Campos, K.; Prohaska, N.; Ferreira, M. L.; Nelson, B. W.; Saleska, S. R.; da Silva, R.

    2014-12-01

    Metabolism and phenology of tropical forests significantly influence global dynamics of climate, carbon and water. However, there is still lack of mechanistic understanding of the controls on tropical forest metabolism, particularly at individual tree level. In this study, we are interested in investigating (1) what is the seasonal pattern of woody growth for tropical trees and (2) what is the mechanistic controls onwoody growth at individual level?To explore the above questions,we use two data sources from an evergreen tropical forest KM67 site (near Santarem, Brazil). They are: (1) image time series from a tower mounted RGB imaging system, with images recordedin10 minutes interval since October 2013.Images near local noon homogeneous diffuse lighting were selectedfor leaf phenologymonitoring; (2) ground based bi-weekly biometry survey (via dendrometry band technique) for 25 trees from random sampling since September 2013. 12 among 25 trees are within the tower mounted camera image view. Our preliminary resultsdemonstrate that 20 trees among 25 trees surveyed significantly increase woody growth (or "green up") in dry season. Our results also find thatamong those 20 trees, 12 trees reaches the maximum woody increment rate in late dry season with a mean DBH (Diameter at Breast Height) around 30 cm,while 8 trees reaching the maximum in the middle of wet season, with a mean DBH around 90 cm. This study,though limited in the sample size, mightprovide another line of evidence that Amazon rainforests "green up" in dry season. As for mechanistic controls on tropical tree woody control, we hypothesize both climate and leaf phenology control individual woody growth. We would like to link both camera based leaf phenology and climate data in the next to explorethe reason as to the pattern found in this study that bigger trees might have different seasonal growth pattern as smaller trees.

  13. Monitoring phenology of photosynthesis in temperate evergreen and mixed deciduous forests using the normalized difference vegetation index (NDVI) and the photochemical reflectance index (PRI) at leaf and canopy scales

    NASA Astrophysics Data System (ADS)

    Wong, C. Y.; Arain, M. A.; Ensminger, I.

    2016-12-01

    Evergreen conifers in boreal and temperate regions undergo strong seasonal changes in photoperiod and temperatures, which determines their phenology of high photosynthetic activity in the growing season and downregulation during the winter. Monitoring the timing of the transition between summer activity and winter downregulation in evergreens is difficult since this is a largely invisible process, unlike in deciduous trees that have a visible budding and a sequence of leaf unfolding in the spring and leaf abscission in the fall. The light-use efficiency (LUE) model estimates gross primary productivity (GPP) and may be parameterized using remotely sensed vegetation indices. Using spectral reflectance data, we derived the normalized difference vegetation index (NDVI), a measure of leaf "greenness", and the photochemical reflectance index (PRI), a proxy for chlorophyll:carotenoid ratios which is related to photosynthetic activity. To better understand the relationship between these vegetation indices and photosynthetic activity and to contrast this relationship between plant functional types, the phenology of NDVI, PRI and photosynthesis was monitored in an evergreen forest and a mixed deciduous forest at the leaf and canopy scale. Our data indicates that the LUE model can be parameterized by NDVI and PRI to track forest phenology. Differences in the sensitivity of PRI and NDVI will be discussed. These findings have implications to address the phenology of evergreen conifers by using PRI to complement NDVI in the LUE model, potentially improving model productivity estimates in northern hemisphere forests, that are dominated by conifers.

  14. [Characterization of mid-subtropical evergreen broad-leaved forest gap based on light detection and ranging (LiDAR)].

    PubMed

    Liu, Feng; Tan, Chang; Wang, Hong; Zhang, Jiang; Wan, Ying; Long, Jiang-ping; Liu, Rui-xi

    2015-12-01

    Light Detection and Ranging (LiDAR) is an active remote sensing technology for acqui- ring three-dimensional structure parameters of vegetation canopy with high accuracy over multiple spatial scales, which is greatly important to the promotion of forest disturbance ecology and the ap- plication on gaps. This paper focused on mid-subtropical evergreen broadleaved forest in Hunan Province, and small footprint LiDAR point data were adopted to identify canopy gaps. and measure geomagnetic characteristics of gaps. The optimal grid model resolution and interpolation methods were chosen to generate canopy height model, and the computer graphics processing was adopted to estimate characteristics of gaps which involved gap size, canopy height and gap shape index, then field investigation was utilized to validate the estimation results. The results showed that the gap rec- ognition rate was 94.8%, and the major influencing factors were gap size and gap maker type. Line- ar correlation was observed between LiDAR estimation and field investigation, and the R² values of gap size and canopy height case were 0.962 and 0.878, respectively. Compared with field investiga- tion, the size of mean estimated gap was 19.9% larger and the mean estimated canopy height was 9.9% less. Gap density was 12.8 gaps · hm⁻² and the area of gaps occupied 13.3% of the forest area. The average gap size, canopy height and gap shape index were 85.06 m², 15.33 m and 1.71, respectively. The study site usually contained small gaps in which the edge effect was not obvious.

  15. Water use efficiency in a primary subtropical evergreen forest in Southwest China

    PubMed Central

    Song, Qing-Hai; Fei, Xue-Hai; Zhang, Yi-Ping; Sha, Li-Qing; Liu, Yun-Tong; Zhou, Wen-Jun; Wu, Chuan-Sheng; Lu, Zhi-Yun; Luo, Kang; Gao, Jin-Bo; Liu, Yu-Hong

    2017-01-01

    We calculated water use efficiency (WUE) using measures of gross primary production (GPP) and evapotranspiration (ET) from five years of continuous eddy covariance measurements (2009–2013) obtained over a primary subtropical evergreen broadleaved forest in southwestern China. Annual mean WUE exhibited a decreasing trend from 2009 to 2013, varying from ~2.28 to 2.68 g C kg H2O−1. The multiyear average WUE was 2.48 ± 0.17 (mean ± standard deviation) g C kg H2O−1. WUE increased greatly in the driest year (2009), due to a larger decline in ET than in GPP. At the diurnal scale, WUE in the wet season reached 5.1 g C kg H2O−1 in the early morning and 4.6 g C kg H2O−1 in the evening. WUE in the dry season reached 3.1 g C kg H2O−1 in the early morning and 2.7 g C kg H2O−1 in the evening. During the leaf emergence stage, the variation of WUE could be suitably explained by water-related variables (relative humidity (RH), soil water content at 100 cm (SWC_100)), solar radiation and the green index (Sgreen). These results revealed large variation in WUE at different time scales, highlighting the importance of individual site characteristics. PMID:28216656

  16. Winter photosynthesis by saplings of evergreen broad-leaved trees in a deciduous temperate forest.

    PubMed

    Miyazawa, Yoshiyuki; Kikuzawa, Kihachiro

    2005-03-01

    * Here we investigated photosynthetic traits of evergreen species under a deciduous canopy in a temperate forest and revealed the importance of CO2 assimilation during winter for annual CO2 assimilation. * Saplings were shaded by the canopy trees from spring through to autumn, but were less shaded during the winter months. Photosynthetic rates at light saturation (Aarea) were lower during winter than during the growing season. Aarea was higher in Camellia, Ilex and Photinia than in Castanopsis, Cleyera and Quercus during the winter, but differed little during summer and autumn. * Estimated daily CO2 assimilation (Aday) was higher during the winter than during the growing season in Camellia, Ilex and Photinia but was higher than that during the growing season only at the beginning and end of winter in Castanopsis, Cleyera and Quercus. Aday was higher in Camellia, Ilex and Photinia than in Castanopsis, Cleyera and Quercus but differed little among them during the growing season. * These results reveal the importance of winter CO2 assimilation for the growth of Camellia, Ilex and Photinia. Furthermore, differences in annual CO2 assimilation among species are strongly modified by species-specific photosynthetic traits during the winter under deciduous canopy trees.

  17. Water use efficiency in a primary subtropical evergreen forest in Southwest China

    NASA Astrophysics Data System (ADS)

    Song, Qing-Hai; Fei, Xue-Hai; Zhang, Yi-Ping; Sha, Li-Qing; Liu, Yun-Tong; Zhou, Wen-Jun; Wu, Chuan-Sheng; Lu, Zhi-Yun; Luo, Kang; Gao, Jin-Bo; Liu, Yu-Hong

    2017-02-01

    We calculated water use efficiency (WUE) using measures of gross primary production (GPP) and evapotranspiration (ET) from five years of continuous eddy covariance measurements (2009–2013) obtained over a primary subtropical evergreen broadleaved forest in southwestern China. Annual mean WUE exhibited a decreasing trend from 2009 to 2013, varying from ~2.28 to 2.68 g C kg H2O‑1. The multiyear average WUE was 2.48 ± 0.17 (mean ± standard deviation) g C kg H2O‑1. WUE increased greatly in the driest year (2009), due to a larger decline in ET than in GPP. At the diurnal scale, WUE in the wet season reached 5.1 g C kg H2O‑1 in the early morning and 4.6 g C kg H2O‑1 in the evening. WUE in the dry season reached 3.1 g C kg H2O‑1 in the early morning and 2.7 g C kg H2O‑1 in the evening. During the leaf emergence stage, the variation of WUE could be suitably explained by water-related variables (relative humidity (RH), soil water content at 100 cm (SWC_100)), solar radiation and the green index (Sgreen). These results revealed large variation in WUE at different time scales, highlighting the importance of individual site characteristics.

  18. Evaluating Spatial-Temporal Dynamics of Net Primary Productivity of Different Forest Types in Northeastern China Based on Improved FORCCHN

    PubMed Central

    Zhao, Junfang; Yan, Xiaodong; Guo, Jianping; Jia, Gensuo

    2012-01-01

    An improved individual-based forest ecosystem carbon budget model for China (FORCCHN) was applied to investigate the spatial-temporal dynamics of net primary productivity of different forest types in northeastern China. In this study, the forests of northeastern China were categorized into four ecological types according to their habitats and generic characteristics (evergreen broadleaf forest, deciduous broadleaf forest, evergreen needleleaf forest and deciduous needleleaf forest). The results showed that distribution and change of forest NPP in northeastern China were related to the different forest types. From 1981 to 2002, among the forest types in northeastern China, per unit area NPP and total NPP of deciduous broadleaf forest were the highest, with the values of 729.4 gC/(m2•yr) and 106.0 TgC/yr, respectively, followed by mixed broadleaf- needleleaf forest, deciduous needleleaf forest and evergreen needleleaf forest. From 1981 to 2002, per unit area NPP and total NPP of different forest types in northeastern China exhibited significant trends of interannual increase, and rapid increase was found between the 1980s and 1990s. The contribution of the different forest type’s NPP to total NPP in northeastern China was clearly different. The greatest was deciduous broadleaf forest, followed by mixed broadleaf- needleleaf forest and deciduous needleleaf forest. The smallest was evergreen needleleaf forest. Spatial difference in NPP between different forest types was remarkable. High NPP values of deciduous needleleaf forest, mixed broadleaf- needleleaf forest and deciduous broadleaf forest were found in the Daxing’anling region, the southeastern of Xiaoxing’anling and Jilin province, and the Changbai Mountain, respectively. However, no regional differences were found for evergreen needleleaf NPP. This study provided not only an estimation NPP of different forest types in northeastern China but also a useful methodology for estimating forest carbon storage

  19. Satellite chlorophyll fluorescence measurements reveal large-scale decoupling of photosynthesis and greenness dynamics in boreal evergreen forests.

    PubMed

    Walther, Sophia; Voigt, Maximilian; Thum, Tea; Gonsamo, Alemu; Zhang, Yongguang; Köhler, Philipp; Jung, Martin; Varlagin, Andrej; Guanter, Luis

    2016-09-01

    Mid-to-high latitude forests play an important role in the terrestrial carbon cycle, but the representation of photosynthesis in boreal forests by current modelling and observational methods is still challenging. In particular, the applicability of existing satellite-based proxies of greenness to indicate photosynthetic activity is hindered by small annual changes in green biomass of the often evergreen tree population and by the confounding effects of background materials such as snow. As an alternative, satellite measurements of sun-induced chlorophyll fluorescence (SIF) can be used as a direct proxy of photosynthetic activity. In this study, the start and end of the photosynthetically active season of the main boreal forests are analysed using spaceborne SIF measurements retrieved from the GOME-2 instrument and compared to that of green biomass, proxied by vegetation indices including the Enhanced Vegetation Index (EVI) derived from MODIS data. We find that photosynthesis and greenness show a similar seasonality in deciduous forests. In high-latitude evergreen needleleaf forests, however, the length of the photosynthetically active period indicated by SIF is up to 6 weeks longer than the green biomass changing period proxied by EVI, with SIF showing a start-of-season of approximately 1 month earlier than EVI. On average, the photosynthetic spring recovery as signalled by SIF occurs as soon as air temperatures exceed the freezing point (2-3 °C) and when the snow on the ground has not yet completely melted. These findings are supported by model data of gross primary production and a number of other studies which evaluated in situ observations of CO2 fluxes, meteorology and the physiological state of the needles. Our results demonstrate the sensitivity of space-based SIF measurements to light-use efficiency of boreal forests and their potential for an unbiased detection of photosynthetic activity even under the challenging conditions interposed by evergreen

  20. Modern pollen-rain characteristics of tall terra firme moist evergreen forest, southern Amazonia

    NASA Astrophysics Data System (ADS)

    Gosling, William D.; Mayle, Francis E.; Tate, Nicholas J.; Killeen, Timothy J.

    2005-11-01

    The paucity of modern pollen-rain data from Amazonia constitutes a significant barrier to understanding the Late Quaternary vegetation history of this globally important tropical forest region. Here, we present the first modern pollen-rain data for tall terra firme moist evergreen Amazon forest, collected between 1999 and 2001 from artificial pollen traps within a 500 × 20 m permanent study plot (14°34'50″S, 60°49'48″W) in Noel Kempff Mercado National Park (NE Bolivia). Spearman's rank correlations were performed to assess the extent of spatial and inter-annual variability in the pollen rain, whilst statistically distinctive taxa were identified using Principal Components Analysis (PCA). Comparisons with the floristic and basal area data of the plot (stems ≥10 cm d.b.h.) enabled the degree to which taxa are over/under-represented in the pollen rain to be assessed (using R-rel values). Moraceae/Urticaceae dominates the pollen rain (64% median abundance) and is also an important constituent of the vegetation, accounting for 16% of stems ≥10 cm d.b.h. and ca. 11% of the total basal area. Other important pollen taxa are Arecaceae (cf. Euterpe), Melastomataceae/Combretaceae, Cecropia, Didymopanax, Celtis, and Alchornea. However, 75% of stems and 67% of the total basal area of the plot ≥10 cm d.b.h. belong to species which are unidentified in the pollen rain, the most important of which are Phenakospermum guianensis (a banana-like herb) and the key canopy-emergent trees, Erisma uncinatum and Qualea paraensis.

  1. Idiosyncratic responses of evergreen broad-leaved forest constituents in China to the late Quaternary climate changes

    PubMed Central

    Fan, Dengmei; Hu, Wan; Li, Bo; Morris, Ashley B.; Zheng, Min; Soltis, Douglas E.; Soltis, Pamela S.; Zhang, Zhiyong

    2016-01-01

    Subtropical evergreen broad-leaved forest (EBLF) is one of the most important vegetation types in China. Inferences from palaeo-biome reconstruction (PBR) and phylogeography regarding range shift history of EBLF during the late Quaternary are controversial and should be reconciled. We compared phylogeographic patterns of three EBLF constituents in China, Castanopsis tibetana, Machilus thunbergii and Schima superba. Contrary to a chorus of previous phylogeographic studies and the results of species distribution modelling (SDM) of this study (in situ survival during the LGM), the three species displayed three different phylogeographic patterns that conform to either an in situ survival model or an expansion-contraction model. These results are partially congruent with the inference of PBR that EBLF was absent to the north of 24° N at the LGM. This study suggests that the constituents of EBLF could have responded idiosyncratically to climate changes during the Late Quaternary. The community assemblages of EBLF could have been changing over time, resulting in no palaeo-analogs to modern-day EBLF, which may be the main reason responsible for the failure of PBR to detect the occurrence of EBLF north of 24° N at the LGM. PMID:27534981

  2. Effect of urbanization on the structure and functional traits of remnant subtropical evergreen broad-leaved forests in South China.

    PubMed

    Huang, Liujing; Chen, Hongfeng; Ren, Hai; Wang, Jun; Guo, Qinfeng

    2013-06-01

    We investigated the effects of major environmental drivers associated with urbanization on species diversity and plant functional traits (PFTs) in the remnant subtropical evergreen broad-leaved forests in Metropolitan Guangzhou (Guangdong, China). Twenty environmental factors including topography, light, and soil properties were used to quantify the effects of urbanization. Vegetation data and soil properties were collected from 30 400-m(2) plots at 6 study sites in urban and rural areas. The difference of plant species diversity and PFTs of remnant forests between urban and rural areas were analyzed. To discern the complex relationships, multivariate statistical analyses (e.g., canonical correspondence analysis and regression analysis) were employed. Pioneer species and stress-tolerant species can survive and vigorously establish their population dominance in the urban environment. The native herb diversity was lower in urban forests than in rural forests. Urban forests tend to prefer the species with Mesophanerophyte life form. In contrast, species in rural forests possessed Chamaephyte and Nanophanerophyte life forms and gravity/clonal growth dispersal mode. Soil pH and soil nutrients (K, Na, and TN) were positively related to herb diversity, while soil heavy metal concentrations (Cu) were negatively correlated with herb diversity. The herb plant species diversity declines and the species in the remnant forests usually have stress-tolerant functional traits in response to urbanization. The factors related to urbanization such as soil acidification, nutrient leaching, and heavy metal pollution were important in controlling the plant diversity in the forests along the urban-rural gradients. Urbanization affects the structure and functional traits of remnant subtropical evergreen broad-leaved forests.

  3. Forest type influences transmission of Phytophthora ramorum in California oak woodlands.

    PubMed

    Davidson, Jennifer M; Patterson, Heather A; Wickland, Allison C; Fichtner, Elizabeth J; Rizzo, David M

    2011-04-01

    The transmission ecology of Phytophthora ramorum from bay laurel (Umbellularia californica) leaves was compared between mixed-evergreen and redwood forest types throughout winter and summer disease cycles in central, coastal California. In a preliminary multisite study, we found that abscission rates of infected leaves were higher at mixed-evergreen sites. In addition, final infection counts were slightly higher at mixed-evergreen sites or not significantly different than at redwood sites, in part due to competition from other foliar pathogens at redwood sites. In a subsequent, detailed study of paired sites where P. ramorum was the main foliar pathogen, summer survival of P. ramorum in bay laurel leaves was lower in mixed-evergreen forest due to lower recovery from infected attached leaves and higher abscission rates of infected leaves. Onset of inoculum production and new infections of bay laurel leaves occurred later in mixed-evergreen forest. Mean inoculum levels in rainwater and final infection counts on leaves were higher in redwood forest. Based on these two studies, lower summer survival of reservoir inoculum in bay laurel leaves in mixed-evergreen forest may result in delayed onset of both inoculum production and new infections, leading to slower disease progress in the early rainy season compared with redwood forest. Although final infection counts also will depend on other foliar pathogens and disease history, in sites where P. ramorum is the main foliar pathogen, these transmission patterns suggest higher rates of disease spread in redwood forests during rainy seasons of short or average length.

  4. Biogeographic variation in evergreen conifer needle longevity and impacts on boreal forest carbon cycle projections

    PubMed Central

    Reich, Peter B.; Rich, Roy L.; Lu, Xingjie; Wang, Ying-Ping; Oleksyn, Jacek

    2014-01-01

    Leaf life span is an important plant trait associated with interspecific variation in leaf, organismal, and ecosystem processes. We hypothesized that intraspecific variation in gymnosperm needle traits with latitude reflects both selection and acclimation for traits adaptive to the associated temperature and moisture gradient. This hypothesis was supported, because across 127 sites along a 2,160-km gradient in North America individuals of Picea glauca, Picea mariana, Pinus banksiana, and Abies balsamea had longer needle life span and lower tissue nitrogen concentration with decreasing mean annual temperature. Similar patterns were noted for Pinus sylvestris across a north–south gradient in Europe. These differences highlight needle longevity as an adaptive feature important to ecological success of boreal conifers across broad climatic ranges. Additionally, differences in leaf life span directly affect annual foliage turnover rate, which along with needle physiology partially regulates carbon cycling through effects on gross primary production and net canopy carbon export. However, most, if not all, global land surface models parameterize needle longevity of boreal evergreen forests as if it were a constant. We incorporated temperature-dependent needle longevity and %nitrogen, and biomass allocation, into a land surface model, Community Atmosphere Biosphere Land Exchange, to assess their impacts on carbon cycling processes. Incorporating realistic parameterization of these variables improved predictions of canopy leaf area index and gross primary production compared with observations from flux sites. Finally, increasingly low foliage turnover and biomass fraction toward the cold far north indicate that a surprisingly small fraction of new biomass is allocated to foliage under such conditions. PMID:25225397

  5. Biogeographic variation in evergreen conifer needle longevity and impacts on boreal forest carbon cycle projections.

    PubMed

    Reich, Peter B; Rich, Roy L; Lu, Xingjie; Wang, Ying-Ping; Oleksyn, Jacek

    2014-09-23

    Leaf life span is an important plant trait associated with interspecific variation in leaf, organismal, and ecosystem processes. We hypothesized that intraspecific variation in gymnosperm needle traits with latitude reflects both selection and acclimation for traits adaptive to the associated temperature and moisture gradient. This hypothesis was supported, because across 127 sites along a 2,160-km gradient in North America individuals of Picea glauca, Picea mariana, Pinus banksiana, and Abies balsamea had longer needle life span and lower tissue nitrogen concentration with decreasing mean annual temperature. Similar patterns were noted for Pinus sylvestris across a north-south gradient in Europe. These differences highlight needle longevity as an adaptive feature important to ecological success of boreal conifers across broad climatic ranges. Additionally, differences in leaf life span directly affect annual foliage turnover rate, which along with needle physiology partially regulates carbon cycling through effects on gross primary production and net canopy carbon export. However, most, if not all, global land surface models parameterize needle longevity of boreal evergreen forests as if it were a constant. We incorporated temperature-dependent needle longevity and %nitrogen, and biomass allocation, into a land surface model, Community Atmosphere Biosphere Land Exchange, to assess their impacts on carbon cycling processes. Incorporating realistic parameterization of these variables improved predictions of canopy leaf area index and gross primary production compared with observations from flux sites. Finally, increasingly low foliage turnover and biomass fraction toward the cold far north indicate that a surprisingly small fraction of new biomass is allocated to foliage under such conditions.

  6. Fragmentation and management of Ethiopian moist evergreen forest drive compositional shifts of insect communities visiting wild Arabica coffee flowers.

    PubMed

    Berecha, Gezahegn; Aerts, Raf; Muys, Bart; Honnay, Olivier

    2015-02-01

    Coffea arabica is an indigenous understorey shrub of the moist evergreen Afromontane forest of SW Ethiopia. Coffee cultivation here occurs under different forest management intensities, ranging from almost no intervention in the 'forest coffee' system to far-reaching interventions that include the removal of competing shrubs and selective thinning of the upper canopy in the 'semi-forest coffee' system. We investigated whether increasing forest management intensity and fragmentation result in impacts upon potential coffee pollination services through examining shifts in insect communities that visit coffee flowers. Overall, we netted 2,976 insect individuals on C. arabica flowers, belonging to sixteen taxonomic groups, comprising 10 insect orders. Taxonomic richness of the flower-visiting insects significantly decreased and pollinator community changed with increasing forest management intensity and fragmentation. The relative abundance of honey bees significantly increased with increasing forest management intensity and fragmentation, likely resulting from the introduction of bee hives in the most intensively managed forests. The impoverishment of the insect communities through increased forest management intensity and fragmentation potentially decreases the resilience of the coffee production system as pollination increasingly relies on honey bees alone. This may negatively affect coffee productivity in the long term as global pollination services by managed honey bees are expected to decline under current climate change scenarios. Coffee agroforestry management practices should urgently integrate pollinator conservation measures.

  7. Fragmentation and Management of Ethiopian Moist Evergreen Forest Drive Compositional Shifts of Insect Communities Visiting Wild Arabica Coffee Flowers

    NASA Astrophysics Data System (ADS)

    Berecha, Gezahegn; Aerts, Raf; Muys, Bart; Honnay, Olivier

    2015-02-01

    Coffea arabica is an indigenous understorey shrub of the moist evergreen Afromontane forest of SW Ethiopia. Coffee cultivation here occurs under different forest management intensities, ranging from almost no intervention in the `forest coffee' system to far-reaching interventions that include the removal of competing shrubs and selective thinning of the upper canopy in the `semi-forest coffee' system. We investigated whether increasing forest management intensity and fragmentation result in impacts upon potential coffee pollination services through examining shifts in insect communities that visit coffee flowers. Overall, we netted 2,976 insect individuals on C. arabica flowers, belonging to sixteen taxonomic groups, comprising 10 insect orders. Taxonomic richness of the flower-visiting insects significantly decreased and pollinator community changed with increasing forest management intensity and fragmentation. The relative abundance of honey bees significantly increased with increasing forest management intensity and fragmentation, likely resulting from the introduction of bee hives in the most intensively managed forests. The impoverishment of the insect communities through increased forest management intensity and fragmentation potentially decreases the resilience of the coffee production system as pollination increasingly relies on honey bees alone. This may negatively affect coffee productivity in the long term as global pollination services by managed honey bees are expected to decline under current climate change scenarios. Coffee agroforestry management practices should urgently integrate pollinator conservation measures.

  8. Influences of evergreen gymnosperm and deciduous angiosperm tree species on the functioning of temperate and boreal forests.

    PubMed

    Augusto, Laurent; De Schrijver, An; Vesterdal, Lars; Smolander, Aino; Prescott, Cindy; Ranger, Jacques

    2015-05-01

    It has been recognized for a long time that the overstorey composition of a forest partly determines its biological and physical-chemical functioning. Here, we review evidence of the influence of evergreen gymnosperm (EG) tree species and deciduous angiosperm (DA) tree species on the water balance, physical-chemical soil properties and biogeochemical cycling of carbon and nutrients. We used scientific publications based on experimental designs where all species grew on the same parent material and initial soil, and were similar in stage of stand development, former land use and current management. We present the current state of the art, define knowledge gaps, and briefly discuss how selection of tree species can be used to mitigate pollution or enhance accumulation of stable organic carbon in the soil. The presence of EGs generally induces a lower rate of precipitation input into the soil than DAs, resulting in drier soil conditions and lower water discharge. Soil temperature is generally not different, or slightly lower, under an EG canopy compared to a DA canopy. Chemical properties, such as soil pH, can also be significantly modified by taxonomic groups of tree species. Biomass production is usually similar or lower in DA stands than in stands of EGs. Aboveground production of dead organic matter appears to be of the same order of magnitude between tree species groups growing on the same site. Some DAs induce more rapid decomposition of litter than EGs because of the chemical properties of their tissues, higher soil moisture and favourable conditions for earthworms. Forest floors consequently tend to be thicker in EG forests compared to DA forests. Many factors, such as litter lignin content, influence litter decomposition and it is difficult to identify specific litter-quality parameters that distinguish litter decomposition rates of EGs from DAs. Although it has been suggested that DAs can result in higher accumulation of soil carbon stocks, evidence from

  9. [Biogeographic regionalization of the mammals of tropical evergreen forests in Mesoamerica].

    PubMed

    Olguin-Monroy, Hector C; Gutiérrez-Blando, Cirene; Rios-Muñoz, César A; León-Paniagua, Livia; Navarro-Sigüenza, Adolfo G

    2013-06-01

    Mesoamerica is a biologically complex zone that expands from Southern Mexico to extreme Northern Colombia. The biogeographical patterns and relationships of the mammalian fauna associated to the Mesoamerican Tropical Evergreen Forest (MTEF) are poorly understood, in spite of the wide distribution of this kind of habitat in the region. We compiled a complete georeferenced database of mammalian species distributed in the MTEF of specimens from museum collections and scientific literature. This database was used to create potential distribution maps through the use of environmental niche models (ENMs) by using the Genetic Algorithm for Rule-Set Production (GARP) using 22 climatic and topographic layers. Each map was used as a representation of the geographic distribution of the species and all available maps were summed to obtain general patterns of species richness in the region. Also, the maps were used to construct a presence-absence matrix in a grid of squares of 0.5 degrees of side, that was analyzed in a Parsimony Analysis of Endemicity (PAE), which resulted in a hypothesis of the biogeographic scheme in the region. We compiled a total of 41 527 records of 233 species of mammals associated to the MTEF. The maximum concentration of species richness (104-138 species) is located in the areas around the Isthmus of Tehuantepec, Northeastern Chiapas-Western Guatemala, Western Honduras, Central Nicaragua to Northwestern Costa Rica and Western Panama. The proposed regionalization indicates that mammalian faunas associated to these forests are composed of two main groups that are divided by the Isthmus of Tehuantepec in Oaxaca in: a) a Northern group that includes Sierra Madre of Chiapas-Guatemala and Yucatan Peninsula; and b) an austral group, that contains the Pacific slope of Chiapas towards the South including Central America. Some individual phylogenetic studies of mammal species in the region support the relationships between the areas of endemism proposed, which

  10. Greater diversity of soil fungal communities and distinguishable seasonal variation in temperate deciduous forests compared with subtropical evergreen forests of eastern China.

    PubMed

    He, Jinhong; Tedersoo, Leho; Hu, Ang; Han, Conghai; He, Dan; Wei, Hui; Jiao, Min; Anslan, Sten; Nie, Yanxia; Jia, Yongxia; Zhang, Gengxin; Yu, Guirui; Liu, Shirong; Shen, Weijun

    2017-07-01

    Whether and how seasonality of environmental variables impacts the spatial variability of soil fungal communities remain poorly understood. We assessed soil fungal diversity and community composition of five Chinese zonal forests along a latitudinal gradient spanning 23°N to 42°N in three seasons to address these questions. We found that soil fungal diversity increased linearly or parabolically with latitude. The seasonal variations in fungal diversity were more distinguishable in three temperate deciduous forests than in two subtropical evergreen forests. Soil fungal diversity was mainly correlated with edaphic factors such as pH and nutrient contents. Both latitude and its interactions with season also imposed significant impacts on soil fungal community composition (FCC), but the effects of latitude were stronger than those of season. Vegetational properties such as plant diversity and forest age were the dominant factors affecting FCC in the subtropical evergreen forests while edaphic properties were the dominant ones in the temperate deciduous forests. Our results indicate that latitudinal variation patterns of soil fungal diversity and FCC may differ among seasons. The stronger effect of latitude relative to that of season suggests a more important influence by the spatial than temporal heterogeneity in shaping soil fungal communities across zonal forests. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Landscape dynamics in Mediterranean oak forests under global change: understanding the role of anthropogenic and environmental drivers across forest types.

    PubMed

    Acácio, Vanda; Dias, Filipe S; Catry, Filipe X; Rocha, Marta; Moreira, Francisco

    2017-03-01

    The Mediterranean region is projected to be extremely vulnerable to global change, which will affect the distribution of typical forest types such as native oak forests. However, our understanding of Mediterranean oak forest responses to future conditions is still very limited by the lack of knowledge on oak forest dynamics and species-specific responses to multiple drivers. We compared the long-term (1966-2006) forest persistence and land cover change among evergreen (cork oak and holm oak) and deciduous oak forests and evaluated the importance of anthropogenic and environmental drivers on observed changes for Portugal. We used National Forest Inventories to quantify the changes in oak forests and explored the drivers of change using multinomial logistic regression analysis and an information theoretical approach. We found distinct trends among oak forest types, reflecting the differences in oak economic value, protection status and management schemes: cork oak forests were the most persistent (62%), changing mostly to pines and eucalypt; holm oak forests were less persistent (53.2%), changing mostly to agriculture; and deciduous oak forests were the least persistent (45.7%), changing mostly to shrublands. Drivers of change had distinct importance across oak forest types, but drivers from anthropogenic origin (wildfires, population density, and land accessibility) were always among the most important. Climatic extremes were also important predictors of oak forest changes, namely extreme temperatures for evergreen oak forests and deficit of precipitation for deciduous oak forests. Our results indicate that under increasing human pressure and forecasted climate change, evergreen oak forests will continue declining and deciduous oak forests will be replaced by forests dominated by more xeric species. In the long run, multiple disturbances may change competitive dominance from oak forests to pyrophytic shrublands. A better understanding of forest dynamics and the

  12. Seasonal variations of gas exchange and water relations in deciduous and evergreen trees in monsoonal dry forests of Thailand.

    PubMed

    Ishida, Atsushi; Harayama, Hisanori; Yazaki, Kenichi; Ladpala, Phanumard; Sasrisang, Amornrat; Kaewpakasit, Kanokwan; Panuthai, Samreong; Staporn, Duriya; Maeda, Takahisa; Gamo, Minoru; Diloksumpun, Sapit; Puangchit, Ladawan; Ishizuka, Moriyoshi

    2010-08-01

    This study compared leaf gas exchange, leaf hydraulic conductance, twig hydraulic conductivity and leaf osmotic potential at full turgor between two drought-deciduous trees, Vitex peduncularis Wall. and Xylia xylocarpa (Roxb.) W. Theob., and two evergreen trees, Hopea ferrea Lanessan and Syzygium cumini (L.) Skeels, at the uppermost canopies in tropical dry forests in Thailand. The aims were to examine (i) whether leaf and twig hydraulic properties differ in relation to leaf phenology and (ii) whether xylem cavitation is a determinant of leaf shedding during the dry season. The variations in almost all hydraulic traits were more dependent on species than on leaf phenology. Evergreen Hopea exhibited the lowest leaf-area-specific twig hydraulic conductivity (leaf-area-specific K(twig)), lamina hydraulic conductance (K(lamina)) and leaf osmotic potential at full turgor (Ψ(o)) among species, whereas evergreen Syzygium exhibited the highest leaf-area-specific K(twig), K(lamina) and Ψ(o). Deciduous Xylia had the highest sapwood-area-specific K(twig), along with the lowest Huber value (sapwood area/leaf area). More negative osmotic Ψ(o) and leaf osmotic adjustment during the dry season were found in deciduous Vitex and evergreen Hopea, accompanied by low sapwood-area-specific K(twig). Regarding seasonal changes in hydraulics, no remarkable decrease in K(lamina) and K(twig) was found during the dry season in any species. Results suggest that leaf shedding during the dry season is not always associated with extensive xylem cavitation.

  13. [Spatial analysis of LAIe of montane evergreen broad-leaved forest in southwest Sichuan, Northwest China, based on image texture].

    PubMed

    Zhao, An-Jiu; Yang, Chang-Qing; Liao, Cheng-Yun

    2014-11-01

    Optical remote sensing is still one of the most attractive choices for obtaining leaf area index (LAI) information, but currently may be derived from remotely sensed data with limited accuracy. Effective leaf area index (LAIe) of montane evergreen broad-leaved forest in southwest Sichuan was inventoried and assessed in 83 sample field plots of 20 m x 20 m using different types of image processing techniques, including simple spectral band, simple spectral band ratios and principal component. Texture information was extracted by gray level co-occurrence matrices (GLCM) from different types of processing image. The results showed that there were correlations of different degrees between LAIe and texture parameters, and highly significant correlations were observed between LAIe with the homogeneity of the B1 band, B1/B4 band ratio or principal component PC1. Using texture information of remotely sensed data as auxiliary variables, we developed geostatistics models. Compared with the model based on NDVI auxiliary variable, the accuracy of LAIe were improved, presenting an increase by 5.3% with the homogeneity of the B1 band, 11.0% with the homogeneity B1/B4 band ratio, and 14.5% with the homogeneity principal component PC1, and the statistical errors were also reduced to some extent. The optimal LAIe model of spatial geostatistics was obtained when taking NDVI and homogeneity principal component PC1 as auxiliary variables (R2 = 0.840, RMSE = 0.212). Our results provided a new way to estimate regional spatial distribution of LAI using other auxiliary variables besides the vegetation index.

  14. Modeling the early-phase redistribution of radiocesium fallouts in an evergreen coniferous forest after Chernobyl and Fukushima accidents.

    PubMed

    Calmon, P; Gonze, M-A; Mourlon, Ch

    2015-10-01

    Following the Chernobyl accident, the scientific community gained numerous data on the transfer of radiocesium in European forest ecosystems, including information regarding the short-term redistribution of atmospheric fallout onto forest canopies. In the course of international programs, the French Institute for Radiological Protection and Nuclear Safety (IRSN) developed a forest model, named TREE4 (Transfer of Radionuclides and External Exposure in FORest systems), 15 years ago. Recently published papers on a Japanese evergreen coniferous forest contaminated by Fukushima radiocesium fallout provide interesting and quantitative data on radioactive mass fluxes measured within the forest in the months following the accident. The present study determined whether the approach adopted in the TREE4 model provides satisfactory results for Japanese forests or whether it requires adjustments. This study focused on the interception of airborne radiocesium by forest canopy, and the subsequent transfer to the forest floor through processes such as litterfall, throughfall, and stemflow, in the months following the accident. We demonstrated that TREE4 quite satisfactorily predicted the interception fraction (20%) and the canopy-to-soil transfer (70% of the total deposit in 5 months) in the Tochigi forest. This dynamics was similar to that observed in the Höglwald spruce forest. However, the unexpectedly high contribution of litterfall (31% in 5 months) in the Tochigi forest could not be reproduced in our simulations (2.5%). Possible reasons for this discrepancy are discussed; and sensitivity of the results to uncertainty in deposition conditions was analyzed. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Seasonality of weather and tree phenology in a tropical evergreen mountain rain forest

    NASA Astrophysics Data System (ADS)

    Bendix, J.; Homeier, J.; Cueva Ortiz, E.; Emck, P.; Breckle, S.-W.; Richter, M.; Beck, E.

    2006-07-01

    Flowering and fruiting as phenological events of 12 tree species in an evergreen tropical mountain rain forest in southern Ecuador were examined over a period of 3-4 years. Leaf shedding of two species was observed for 12 months. Parallel to the phenological recordings, meteorological parameters were monitored in detail and related to the flowering and fruiting activity of the trees. In spite of the perhumid climate of that area, a high degree of intra- and inter-specific synchronisation of phenological traits was apparent. With the exception of one species that flowered more or less continuously, two groups of trees could be observed, one of which flowered during the less humid months (September to October) while the second group started to initiate flowers towards the end of that phase and flowered during the heavy rains (April to July). As reflected by correlation coefficients, the all-time series of meteorological parameters showed a distinct seasonality of 8-12 months, apparently following the quasi-periodic oscillation of precipitation and related cloudiness. As revealed by power spectrum analysis and Markov persistence, rainfall and minimum temperature appear to be the only parameters with a periodicity free of long-term variations. The phenological events of most of the plant species showed a similar periodicity of 8-12 months, which followed the annual oscillation of relatively less and more humid periods and thus was in phase or in counter-phase with the oscillations of the meteorological parameters. Periods of unusual cold or dryness, presumably resulting from underlying longer-term trends or oscillations (such as ENSO), affected the homogeneity of quasi-12-month flowering events, fruit maturation and also the production of germinable seeds. Some species show underlying quasi-2-year-oscillations, for example that synchronise with the development of air temperature; others reveal an underlying decrease or increase in flowering activity over the

  16. Foliar temperature tolerance of temperate and tropical evergreen rain forest trees of Australia.

    PubMed

    Cunningham, S C; Read, J

    2006-11-01

    Australian rain forests extend from tropical climates in the north to temperate climates in the south, providing an opportunity to investigate physiological responses to temperature of both temperate and tropical species within the same forest type. Eight, rain forest canopy tree species were selected to cover the 33 degrees latitudinal range of rain forests in eastern Australia. Temperature tolerance was measured in 6-year-old plants grown in a common environment, by exposing leaves to a series of high temperatures during late summer and a series of freezing temperatures during midwinter. Damage was evaluated based on chlorophyll fluorescence measurements made 2 h after exposure and by visual assessment of leaf damage made a week after exposure. Leaves of the tropical species were more heat tolerant and less frost tolerant than leaves of the temperate species, which is consistent with their climate distributions. In contrast, the temperature tolerance of the photosynthetic apparatus was unrelated to climate in a species' native habitat. However, the tropical species underwent significant photoinhibition during winter. All species maintained the integrity of the photosynthetic apparatus and avoided tissue damage over a similar span of temperatures (about 60 degrees C), reflecting the similar annual temperature ranges in Australia's temperate and tropical rain forests. Chlorophyll fluorescence measurements and visual assessment of leaf damage provided different estimates of the absolute and relative temperature tolerances of the species, thus emphasizing the importance of a direct assessment of tissue damage for determining a species' temperature tolerance.

  17. Insect herbivores associated with an evergreen tree Goniorrhachis marginata Taub. (Leguminosae: Caesalpinioideae) in a tropical dry forest.

    PubMed

    Silva, J O; Neves, F S

    2014-08-01

    Goniorrhachis marginata Taub. (Leguminosae: Caesalpinioideae) is a tree species found in Brazilian tropical dry forests that retain their leaves during the dry season. That being, we addressed the following question: i) How do insect diversity (sap-sucking and chewing), leaf herbivory and defensive traits (tannin and leaf sclerophylly) vary on the evergreen tree species G. marginata between seasons? The abundance of sap-sucking insects was higher in the dry season than in the rainy season. However, we did not verify any difference in the species richness and abundance of chewing insects between seasons. Leaf herbivory was higher in the rainy season, whereas leaf sclerophylly was higher in the dry season. However, herbivory was not related to sclerophylly. Insect herbivores likely decrease their folivory activity during the dry season due to life history patterns or changes in behaviour, possibly entering diapause or inactivity during this period. Therefore, G. marginata acts as a likely keystone species, serving as a moist refuge for the insect fauna during the dry season in tropical dry forest, and the presence of this evergreen species is crucial to conservation strategies of this threatened ecosystem.

  18. Changes in structure and composition of evergreen forests on an altitudinal gradient in the Venezuelan Guayana shield.

    PubMed

    Hernández, Lionel; Dezzeo, Nelda; Sanoja, Elio; Salazar, Leandro; Castellanos, Hernán

    2012-03-01

    There have been several ecological studies in forests of the Guayana Shield, but so far none had examined the changes in structure and composition of evergreen forests with altitude. This study describes and analyzes the structure, species composition and soil characteristics of forest stands at different altitudinal zones in Southeastern Venezuelan Guayana, in order to explain the patterns and the main factors that determine the structure and composition of evergreen forests along the altitudinal gradient. Inventories of 3 948 big (>10cm DBH) and 1 328 small (5-10cm DBH) woody stems were carried out in eleven plots, ranging from 0.1 to 1.0ha, along a 188km long transect with elevations between 290 and 1 395masl. It has been found that 1) hemiepihytes become more dominant and lianas reduce their dominance with increasing altitude and 2) the forest structure in the study area is size-dependent. Five families and 12 genera represented only 9% of the total number of families and genera, respectively, recorded troughout the gradient, but the two groups of taxa comprised more than 50% of the Importance Value (the sum of the relative density and the relative dominance) of all measured stems. Moreover, the results suggest that low species richness seems to be associated with the dominance of one or few species. Stand-level wood density (WD) of trees decreased significantly with increasing elevation. WD is an indicator of trees'life history strategy. Its decline suggests a change in the functional composition of the forest with increasing altitude. The Canonical Correspondence Analysis (CCA) indicated a distinction of the studied forests on the basis of their altitudinal levels and geographic location, and revealed different ecological responses by the forests, to environmental variables along the altitudinal gradient. The variation in species composition, in terms of basal area among stands, was controlled primarily by elevation and secondarily by rainfall and soil

  19. [Composition and carbon storage of woody debris in moist evergreen broad-leaved forest and its secondary forests in Ailao Mountains of Yunnan Provinve].

    PubMed

    Yang, Li-Pan; Liu, Wen-Yao; Yang, Guo-Ping; Ma, Wen-Zhang; Li, Da-Wen

    2007-10-01

    This paper studied the composition and carbon storage of woody debris in the primary moist evergreen broad-leaved forest and its main secondary forests (regenerated Lithocarpus forest, Populus bonatii forest, and Alnus nepalensis forest) in Ailao Moutains of Yunnan Province. The results showed that in the primary forest, the carbon storage of woody debris amounted to 36.56 t x hm(-2). Castanopsis wattii, Lithocarpus xylocarpus and L. chintungensis were the main contributors, and most of them were the logs with larger diameter and at intermediate stage of decay. The unique environment of richer precipitation, higher humidity and lower temperature in the study area, and the decay-resistance of hardwood were favorable to the accumulation of woody debris. The three secondary forests had a carbon storage of 1.2-5.0 t x hm(-2), which decreased in the order of regenerated Lithocaropus forest > P. bonatii forest > A. nepalensis forest, showing a tendency of increasing carbon storage with succession course.

  20. A climate change-induced threat to the ecological resilience of a subtropical monsoon evergreen broad-leaved forest in Southern China.

    PubMed

    Zhou, Guoyi; Peng, Changhui; Li, Yuelin; Liu, Shizhong; Zhang, Qianmei; Tang, Xuli; Liu, Juxiu; Yan, Junhua; Zhang, Deqiang; Chu, Guowei

    2013-04-01

    Recent studies have suggested that tropical forests may not be resilient against climate change in the long term, primarily owing to predicted reductions in rainfall and forest productivity, increased tree mortality, and declining forest biomass carbon sinks. These changes will be caused by drought-induced water stress and ecosystem disturbances. Several recent studies have reported that climate change has increased tree mortality in temperate and boreal forests, or both mortality and recruitment rates in tropical forests. However, no study has yet examined these changes in the subtropical forests that account for the majority of China's forested land. In this study, we describe how the monsoon evergreen broad-leaved forest has responded to global warming and drought stress using 32 years of data from forest observation plots. Due to an imbalance in mortality and recruitment, and changes in diameter growth rates between larger and smaller trees and among different functional groups, the average DBH of trees and forest biomass have decreased. Sap flow measurements also showed that larger trees were more stressed than smaller trees by the warming and drying environment. As a result, the monsoon evergreen broad-leaved forest community is undergoing a transition from a forest dominated by a cohort of fewer and larger individuals to a forest dominated by a cohort of more and smaller individuals, with a different species composition, suggesting that subtropical forests are threatened by their lack of resilience against long-term climate change.

  1. Geographical and climatic gradients of evergreen versus deciduous broad-leaved tree species in subtropical China: Implications for the definition of the mixed forest.

    PubMed

    Ge, Jielin; Xie, Zongqiang

    2017-06-01

    Understanding climatic influences on the proportion of evergreen versus deciduous broad-leaved tree species in forests is of crucial importance when predicting the impact of climate change on broad-leaved forests. Here, we quantified the geographical distribution of evergreen versus deciduous broad-leaved tree species in subtropical China. The Relative Importance Value index (RIV) was used to examine regional patterns in tree species dominance and was related to three key climatic variables: mean annual temperature (MAT), minimum temperature of the coldest month (MinT), and mean annual precipitation (MAP). We found the RIV of evergreen species to decrease with latitude at a lapse rate of 10% per degree between 23.5 and 25°N, 1% per degree at 25-29.1°N, and 15% per degree at 29.1-34°N. The RIV of evergreen species increased with: MinT at a lapse rate of 10% per °C between -4.5 and 2.5°C and 2% per °C at 2.5-10.5°C; MAP at a lapse rate of 10% per 100 mm between 900 and 1,600 mm and 4% per 100 mm between 1,600 and 2,250 mm. All selected climatic variables cumulatively explained 71% of the geographical variation in dominance of evergreen and deciduous broad-leaved tree species and the climatic variables, ranked in order of decreasing effects were as follows: MinT > MAP > MAT. We further proposed that the latitudinal limit of evergreen and deciduous broad-leaved mixed forests was 29.1-32°N, corresponding with MAT of 11-18.1°C, MinT of -2.5 to 2.51°C, and MAP of 1,000-1,630 mm. This study is the first quantitative assessment of climatic correlates with the evergreenness and deciduousness of broad-leaved forests in subtropical China and underscores that extreme cold temperature is the most important climatic determinant of evergreen and deciduous broad-leaved tree species' distributions, a finding that confirms earlier qualitative studies. Our findings also offer new insight into the definition and distribution of the mixed forest and an accurate

  2. Seed rain, soil seed bank, seed loss and regeneration of Castanopsis fargesii (Fagaceae) in a subtropical evergreen broad-leaved forest

    Treesearch

    Xiaojun Du; Qinfeng Guo; Xianming Gao; Keping Na

    2007-01-01

    Understanding the seed rain and seed loss dynamics in the natural condition has important significance for revealing the natural regeneration mechanisms.We conducted a 3-year field observation on seed rain, seed loss and natural regeneration of Castanopsis fargesii Franch., a dominant tree species in evergreen broad-leaved forests in Dujiangyan,...

  3. Seasonal abundance and activity of pill millipedes ( Arthrosphaera magna) in mixed plantation and semi-evergreen forest of southern India

    NASA Astrophysics Data System (ADS)

    Ashwini, Krishna M.; Sridhar, Kandikere R.

    2006-01-01

    Seasonal occurrence and activity of endemic pill millipedes ( Arthrosphaera magna) were examined in organically managed mixed plantation and semi-evergreen forest reserve in southwest India between November 1996 and September 1998. Abundance and biomass of millipedes were highest in both habitats during monsoon season. Soil moisture, conductivity, organic carbon, phosphate, potassium, calcium and magnesium were higher in plantation than in forest. Millipede abundance and biomass were about 12 and 7 times higher in plantation than in forest, respectively ( P < 0.001). Their biomass increased during post-monsoon, summer and monsoon in the plantation ( P < 0.001), but not in forest ( P > 0.05). Millipede abundance and biomass were positively correlated with rainfall ( P = 0.01). Besides rainfall, millipedes in plantation were positively correlated with soil moisture as well as temperature ( P = 0.001). Among the associated fauna with pill millipedes, earthworms rank first followed by soil bugs in both habitats. Since pill millipedes are sensitive to narrow ecological changes, the organic farming strategies followed in mixed plantation and commonly practiced in South India seem not deleterious for the endangered pill millipedes Arthrosphaera and reduce the risk of local extinctions.

  4. Differential responses of carbon and water vapor fluxes to climate among evergreen needleleaf forests in the USA

    DOE PAGES

    Wagle, Pradeep; Xiao, Xiangming; Kolb, Thomas E.; ...

    2016-05-31

    Here, understanding the differences in carbon and water vapor fluxes of spatially distributed evergreen needleleaf forests (ENFs) is crucial for accurately estimating regional or global carbon and water budgets and when predicting the responses of ENFs to current and future climate. We compared the fluxes of ten AmeriFlux ENF sites to investigate cross-site variability in net ecosystem exchange of carbon (NEE), gross primary production (GPP), and evapotranspiration (ET). We used wavelet cross-correlation analysis to examine responses of NEE and ET to common climatic drivers over multiple timescales and also determined optimum values of air temperature (T a) and vapor pressuremore » deficit (VPD) for NEE and ET.« less

  5. DNA Barcode Authentication of Wood Samples of Threatened and Commercial Timber Trees within the Tropical Dry Evergreen Forest of India

    PubMed Central

    Nithaniyal, Stalin; Newmaster, Steven G.; Ragupathy, Subramanyam; Krishnamoorthy, Devanathan; Vassou, Sophie Lorraine; Parani, Madasamy

    2014-01-01

    Background India is rich with biodiversity, which includes a large number of endemic, rare and threatened plant species. Previous studies have used DNA barcoding to inventory species for applications in biodiversity monitoring, conservation impact assessment, monitoring of illegal trading, authentication of traded medicinal plants etc. This is the first tropical dry evergreen forest (TDEF) barcode study in the World and the first attempt to assemble a reference barcode library for the trees of India as part of a larger project initiated by this research group. Methodology/Principal Findings We sampled 429 trees representing 143 tropical dry evergreen forest (TDEF) species, which included 16 threatened species. DNA barcoding was completed using rbcL and matK markers. The tiered approach (1st tier rbcL; 2nd tier matK) correctly identified 136 out of 143 species (95%). This high level of species resolution was largely due to the fact that the tree species were taxonomically diverse in the TDEF. Ability to resolve taxonomically diverse tree species of TDEF was comparable among the best match method, the phylogenetic method, and the characteristic attribute organization system method. Conclusions We demonstrated the utility of the TDEF reference barcode library to authenticate wood samples from timber operations in the TDEF. This pilot research study will enable more comprehensive surveys of the illegal timber trade of threatened species in the TDEF. This TDEF reference barcode library also contains trees that have medicinal properties, which could be used to monitor unsustainable and indiscriminate collection of plants from the wild for their medicinal value. PMID:25259794

  6. [Seasonal release characteristics of Ca, Mg and Mn of foliar litter of six tree species in subtropical evergreen broadleaved forest].

    PubMed

    Ma, Zhi-liang; Gao, Shun; Yang, Wan-qin; Wu, Fu-zhong

    2015-10-01

    Seasonal release dynamics of Ca, Mg and Mn during decomposition of foliar litter of Pinus massoniana, Cryptomeria fortunei, Cunninghamia lanceolata, Cinnamomum camphora, Toona ciliate, and Quercus acutissima were investigated in subtropical evergreen broad-leaved forest employing the method of litterbag. After one-year decomposition, the release rates of Ca, Mg and Mn in foliar litter of the studied tree species ranged from -13.8% to 92.3%, from 4.0% to 64.8%, and from 41.6% to 81.1%, respectively. Ca dynamics in foliar litter of P. massoniana, C. camphora exhibited the pattern of accumulating early and releasing later, while that of the other four tree species showed direct release. Similarly, the dynamics of Mg released from foliar litter of C. camphora showed the pattern of accumulating early and then releasing, while that of the other five tree species exhibited continuous release. Meanwhile, the dynamics of Mn released from foliar litter of C. fortunei and T. ciliate exhibited early accumulation, and subsequent release, while that of the other four tree species showed continuous release. The releases of Ca, Mg and Mn in foliar litter were greatly influenced by seasonal rainfall, and varied with tree species. Furthermore, the rates and amounts of Ca, Mg and Mn released from foliar litter were higher in rainy season than in dry season. In conclusion, the initial nutrient concentrations and precipitation were two key factors influencing the release dynamics of Ca, Mg and Mn during decomposition of foliar litter in the subtropical evergreen broad-leaved forest.

  7. Accessing the impacts of bamboo expansion on NPP and N cycling in evergreen broadleaved forest in subtropical China

    PubMed Central

    Song, Qing-ni; Lu, Hui; Liu, Jun; Yang, Jun; Yang, Guang-yao; Yang, Qing-pei

    2017-01-01

    Bamboo (Phyllostachys pubescens) expansion into adjacent forests is a widespread phenomenon in subtropical regions, and it has greatly changed the dominance hierarchy from trees to bamboos. This process may be accompanied by changes in productivity, nutrients accumulation and biogeochemical cycles. We compared the net primary production (NPP) and major pools and fluxes of nitrogen (N) in bamboo-dominant forest (BDF) and neighboring secondary evergreen broadleaved forest (EBF) in South China using the space-for-time substitution method. We found that the mean NPP of the BDF was 30.0 t ha−1 yr−1, which was 51.5% greater than that of the EBF (19.8 t ha−1 yr−1). The plant N pool for the BDF was 37.5% larger than that of the EBF, whereas the soil inorganic N pool significantly decreased by 31.2% with conversion of the EBF to BDF. Additionally, the ratio of N return to N uptake was 0.69 in the BDF and 0.88 in the EBF because of the lower litter N return of the BDF compared with that of the EBF. These results indicated that the expansion of P. pubescens significantly increased the NPP and plant N accumulation but reduced the soil N available pool and slowed the N cycling rate, which could lead to soil degradation. PMID:28067336

  8. Accessing the impacts of bamboo expansion on NPP and N cycling in evergreen broadleaved forest in subtropical China

    NASA Astrophysics Data System (ADS)

    Song, Qing-Ni; Lu, Hui; Liu, Jun; Yang, Jun; Yang, Guang-Yao; Yang, Qing-Pei

    2017-01-01

    Bamboo (Phyllostachys pubescens) expansion into adjacent forests is a widespread phenomenon in subtropical regions, and it has greatly changed the dominance hierarchy from trees to bamboos. This process may be accompanied by changes in productivity, nutrients accumulation and biogeochemical cycles. We compared the net primary production (NPP) and major pools and fluxes of nitrogen (N) in bamboo-dominant forest (BDF) and neighboring secondary evergreen broadleaved forest (EBF) in South China using the space-for-time substitution method. We found that the mean NPP of the BDF was 30.0 t ha-1 yr-1, which was 51.5% greater than that of the EBF (19.8 t ha-1 yr-1). The plant N pool for the BDF was 37.5% larger than that of the EBF, whereas the soil inorganic N pool significantly decreased by 31.2% with conversion of the EBF to BDF. Additionally, the ratio of N return to N uptake was 0.69 in the BDF and 0.88 in the EBF because of the lower litter N return of the BDF compared with that of the EBF. These results indicated that the expansion of P. pubescens significantly increased the NPP and plant N accumulation but reduced the soil N available pool and slowed the N cycling rate, which could lead to soil degradation.

  9. [Clonal plasticity of Iris japonica under different soil and canopy conditions in subtropocal evergreen broad-leaved forest].

    PubMed

    He, Yue-Jun; Han, Wen-Ping; Zhong, Zhang-Cheng

    2011-02-01

    An investigation was made on the growth indices of Iris japonica growing on the yellow soil and Karst soil within a subtropical evergreen broad-leaved forest and in the forest gaps, aimed to approach the clonal plasticity of I. japonica in heterogeneous habitats. The results showed that the ramet height and diameter and the rhizome diameter of I. japonica were significantly higher in yellow soil habitat than in Karst soil habitat, while the individual density was in adverse. Light had significant effects on rhizome diameter, but soil condition had lesser effects under the same light environment. Within the forest of Karst soil habitat, the bud number and flower number of I. japonica were zero, possibly due to the double pressure from soil quality and light environment for the balance between resources uptake and energy assignment and for the sustaining of growth. In a certain extent, I. japonica in yellow soil habitat tended to K strategy via decreasing the individual number for improving competition to adapt environment, while I. japonica in Karst soil habitat tended to r strategy via increasing individual number for sustaining competition capability.

  10. Community composition and cellulase activity of cellulolytic bacteria from forest soils planted with broad-leaved deciduous and evergreen trees.

    PubMed

    Yang, Jiang-Ke; Zhang, Jing-Jing; Yu, Heng-Yu; Cheng, Jian-Wen; Miao, Li-Hong

    2014-02-01

    Cellulolytic bacteria in forest soil provide carbon sources to improve the soil fertility and sustain the nutrient balance of the forest ecological system through the decomposition of cellulosic remains. These bacteria can also be utilized for the biological conversion of biomass into renewable biofuels. In this study, the community compositions and activities of cellulolytic bacteria in the soils of forests planted with broad-leaved deciduous (Chang Qing Garden, CQG) and broad-leaved evergreen (Forest Park, FP) trees in Wuhan, China were resolved through restriction fragment length polymorphism (RFLP) and sequencing analysis of the 16S rRNA gene. All of the isolates exhibited 35 RFLP fingerprint patterns and were clustered into six groups at a similarity level of 50 %. The phylogeny analysis based on the 16S rRNA gene sequence revealed that these RFLP groups could be clustered into three phylogenetic groups and further divided into six subgroups at a higher resolution. Group I consists of isolates from Bacillus cereus, Bacillus subtilis complex (I-A) and from Paenibacillus amylolyticus-related complex (I-B) and exhibited the highest cellulase activity among all of the cellulolytic bacteria isolates. Cluster II consists of isolates belonging to Microbacterium testaceum (II-A), Chryseobacterium indoltheticum (II-B), and Flavobacterium pectinovorum and the related complex (II-C). Cluster III consists of isolates belonging to Pseudomonas putida-related species. The community shift with respect to the plant species and the soil properties was evidenced by the phylogenetic composition of the communities. Groups I-A and I-B, which account for 36.0 % of the cellulolytic communities in the CQG site, are the dominant groups (88.4 %) in the FP site. Alternatively, the ratio of the bacteria belonging to group III (P. putida-related isolates) shifted from 28.0 % in CQG to 4.0 % in FP. The soil nutrient analysis revealed that the CQG site planted with deciduous broad

  11. Central hardwood forest types

    Treesearch

    Ivan L. Sander; Burnell C. Fischer

    1989-01-01

    Each of the four broad forest types, often called associations, that you will read about in these Notes is a complex, highly variable mixture of trees, shrubs, and herbs. This Note describes the species you will generally find in each type.

  12. Capability of models to predict leaf N and P across four seasons for six sub-tropical forest evergreen trees

    NASA Astrophysics Data System (ADS)

    van Deventer, H.; Cho, M. A.; Mutanga, O.; Ramoelo, A.

    2015-03-01

    Nutrient phenology of evergreen subtropical forests of southern Africa is poorly understood. Foliar nitrogen (N) and phosphorous (P) forms key components of photosynthesis and are vulnerable to global change stressors. Remote sensing techniques can potentially map and monitor nutrient phenology, yet models to predict across species, seasons and climatic regions are deficient. This study evaluates the capability of various models, developed from leaf spectra of selected spectral regions and seasons, to predict nutrient concentration across season and species. Seasonal differences in foliar N and P were assessed using a one-way ANalysis Of VAriance (ANOVA). The relationship between leaf spectra and nutrients was assessed using linear regressions between the foliar nutrients and spectral indices. The predictive capability of three models was compared using root mean square error (RMSE) values. Amongst the four seasons, winter leaves showed the highest mean N (2.16%, p < 0.01). However, winter showed the lowest variability of foliar N (coefficient of variation = 8%) compared to the variability of the other three seasons (coefficient of variance > 35%). In fact, between winter and spring, the variability in foliar N increased by 294%. Foliar P did not significantly differ between the four seasons. Predictive models for leaf N concentration developed for each season showed a higher level of accuracy, particularly for winter, whereas predictive models for leaf P showed low accuracies. Models developed from a single season showed a slight increase in error for the summer and autumn, however a larger increase in error for the winter season for the evergreen trees. The results suggest that spectral measurements can be potentially be used to quantify nutrient phenology at regional scale and monitor the impacts of global change on nutrient phenology and photosynthesis.

  13. Bamboo Expansion Alters Ecosystem NPP and N Cycling of Evergreen Broad-leaved Forest in Subtropical China

    NASA Astrophysics Data System (ADS)

    Lu, H.; Song, Q. N.; Wang, W.

    2016-12-01

    Background and Aims The bamboo (Phyllostachys pubescens) expansion into adjacent forests is a widespread phenomenon in subtropical region, and it has imposed great effects on the species compositions and community structures of cloned ecosystems. This shift in dominant plant life form, from trees to bamboos, may be accompanied by changes in the productivity, standing accumulation of biomass and nutrients and biogeochemical cycles. Methods We compared the net primary production (NPP) and major pools and fluxes of nitrogen (N) in bamboo-dominant forest (BDF) and neighboring secondary evergreen broadleaved forest (EBF) in South China using the space-for-time substitution method. Results The mean annual NPP of BDF was 30.0 t ha-1 a-1, which was 51.5 % greater than that of the EBF (19.8 t ha-1 a-1), with fine root contributed more than 8.2 kg ha-1. The plant N pool for BDF was 37.5% larger than that of the EBF, because of higher N content in P. pubescens tissues relative to that in trees, whereas the soil inorganic N pool significantly decreased in the EBF by 31.2 % compared with that in the BDF. Additionally, the ratio of N return to N uptake was 0.69 in the BDF and 0.88 in the EBF because of the lower litter N return of the BDF compared with that of the EBF. Conclusion These results indicated that the expansion of P. pubescens significantly increased the NPP and plant N accumulation but reduced the soil N available pool and slowed the N cycling rate, which could lead to soil degradation. These findings have great additional information for the assessment of P. pubescens expansion, and enrich our understanding of bamboo expansion into neighboring forests in subtropical China.

  14. Modelling the climatic drivers determining photosynthesis and carbon allocation in evergreen Mediterranean forests using multiproxy long time series

    NASA Astrophysics Data System (ADS)

    Gea-Izquierdo, G.; Guibal, F.; Joffre, R.; Ourcival, J. M.; Simioni, G.; Guiot, J.

    2015-02-01

    Climatic drivers limit several important physiological processes involved in ecosystem carbon dynamics including gross primary productivity (GPP) and carbon allocation in vegetation. Climatic variability limits these two processes differently. We developed an existing mechanistic model to analyse photosynthesis and variability in carbon allocation in two evergreen species at two Mediterranean forests. The model was calibrated using a combination of eddy covariance CO2 flux data, dendrochronological time series of secondary growth and forest inventory data. The model was modified to be climate explicit in the key processes addressing acclimation of photosynthesis and allocation. It succeeded to fit both the high- and the low-frequency response of stand GPP and carbon allocation to the stem. This would support its capability to address both carbon source and sink limitations. Simulations suggest a decrease in mean stomatal conductance in response to environmental changes and an increase in mean annual intrinsic water use efficiency (iWUE) in both species during the last 50 years. However, this was not translated on a parallel increase in ecosystem water use efficiency (WUE). A long-term decrease in annual GPP matched the local trend in precipitation since the 1970s observed in one site. In contrast, GPP did not show a negative trend and the trees buffered the climatic variability observed at the site where long-term precipitation remained stable. In our simulations these temporal changes would be partly related to increasing [CO2] because the model includes biochemical equations where photosynthesis is directly linked to [CO2]. Long-term trends in GPP did not match those in growth, in agreement with the C-sink hypothesis. There is a great potential to use the model with abundant dendrochronological data and analyse forest performance under climate change. This would help to understand how different interfering environmental factors produce instability in the climatic

  15. [Topographic distribution patterns of forest gap within an evergreen broad-leaved forest in Tiantong region of Zhejiang Province, Eastern China].

    PubMed

    Zhang, Zhi-Guo; Ma, Zun-Ping; Liu, He-Ming; Zheng, Ze-Mei; Xie, Yu-Bin; Fang, Xiao-Feng; Wang, Xi-hua

    2013-03-01

    To explore the effects of multi-dimensional topographic factors on forest gap distribution, the forest gaps in a 20 hm2 dynamic monitoring plot of an evergreen broad-leaved forest in Tiantong region of Zhejiang were taken as the objects to study the distribution patterns of the gap fraction, gap density, and gap area under the effects of altitude, slope degree, slope shape, slope aspect, and slope position by using a geographic information system (GIS) software. In the plot, the gap fraction was 13.1% , gap density was 9.5 ind.hm-2, and average gap area was 137.82 m2. Because of the greater intensity of typhoon disturbance at high altitudes, the gap fraction and gap density at the high altitude (> or =500 m) sections were significantly larger than those at the medium and low altitude (<500 m) sections. The heavy precipitation produced by typhoon could easily cause small scale landslide, and thus, lead to the gap fraction and gap density being larger in valley area than in side-slope and ridge. It was suggested that typhoon and its produced heavy precipitation could be the main causes of the significant differences in the forest gaps along the gradients of altitude and slope position.

  16. The phenology of leaf quality and its within-canopy variation is essential for accurate modeling of photosynthesis in tropical evergreen forests.

    PubMed

    Wu, Jin; Serbin, Shawn P; Xu, Xiangtao; Albert, Loren P; Chen, Min; Meng, Ran; Saleska, Scott R; Rogers, Alistair

    2017-04-18

    Leaf quantity (i.e., canopy leaf area index, LAI), quality (i.e., per-area photosynthetic capacity), and longevity all influence the photosynthetic seasonality of tropical evergreen forests. However, these components of tropical leaf phenology are poorly represented in most terrestrial biosphere models (TBMs). Here, we explored alternative options for the representation of leaf phenology effects in TBMs that employ the Farquahar, von Caemmerer & Berry (FvCB) representation of CO2 assimilation. We developed a two-fraction leaf (sun and shade), two-layer canopy (upper and lower) photosynthesis model to evaluate different modeling approaches and assessed three components of phenological variations (i.e., leaf quantity, quality, and within-canopy variation in leaf longevity). Our model was driven by the prescribed seasonality of leaf quantity and quality derived from ground-based measurements within an Amazonian evergreen forest. Modeled photosynthetic seasonality was not sensitive to leaf quantity, but was highly sensitive to leaf quality and its vertical distribution within the canopy, with markedly more sensitivity to upper canopy leaf quality. This is because light absorption in tropical canopies is near maximal for the entire year, implying that seasonal changes in LAI have little impact on total canopy light absorption; and because leaf quality has a greater effect on photosynthesis of sunlit leaves than light limited, shade leaves and sunlit foliage are more abundant in the upper canopy. Our two-fraction leaf, two-layer canopy model, which accounted for all three phenological components, was able to simulate photosynthetic seasonality, explaining ~90% of the average seasonal variation in eddy covariance-derived CO2 assimilation. This work identifies a parsimonious approach for representing tropical evergreen forest photosynthetic seasonality in TBMs that utilize the FvCB model of CO2 assimilation and highlights the importance of incorporating more realistic

  17. The phenology of leaf quality and its within-canopy variation is essential for accurate modeling of photosynthesis in tropical evergreen forests

    DOE PAGES

    Wu, Jin; Serbin, Shawn P.; Xu, Xiangtao; ...

    2017-04-18

    Leaf quantity (i.e., canopy leaf area index, LAI), quality (i.e., per-area photosynthetic capacity), and longevity all influence the photosynthetic seasonality of tropical evergreen forests. However, these components of tropical leaf phenology are poorly represented in most terrestrial biosphere models (TBMs). Here in this paper, we explored alternative options for the representation of leaf phenology effects in TBMs that employ the Farquahar, von Caemmerer & Berry (FvCB) representation of CO2 assimilation. We developed a two-fraction leaf (sun and shade), two-layer canopy (upper and lower) photosynthesis model to evaluate different modeling approaches and assessed three components of phenological variations (i.e., leaf quantity,more » quality, and within-canopy variation in leaf longevity). Our model was driven by the prescribed seasonality of leaf quantity and quality derived from ground-based measurements within an Amazonian evergreen forest. Modeled photosynthetic seasonality was not sensitive to leaf quantity, but was highly sensitive to leaf quality and its vertical distribution within the canopy, with markedly more sensitivity to upper canopy leaf quality. This is because light absorption in tropical canopies is near maximal for the entire year, implying that seasonal changes in LAI have little impact on total canopy light absorption; and because leaf quality has a greater effect on photosynthesis of sunlit leaves than light limited, shade leaves and sunlit foliage are more abundant in the upper canopy. Our two-fraction leaf, two-layer canopy model, which accounted for all three phenological components, was able to simulate photosynthetic seasonality, explaining ~90% of the average seasonal variation in eddy covariance-derived CO2 assimilation. This work identifies a parsimonious approach for representing tropical evergreen forest photosynthetic seasonality in TBMs that utilize the FvCB model of CO2 assimilation and highlights the importance of

  18. Birds' nesting parameters in four forest types in the Pantanal wetland.

    PubMed

    Pinho, J B; Marini, M A

    2014-11-01

    We tested the heterogeneity/productivity hypothesis with respect to the abundance and richness of birds and the vegetation density hypothesis with respect to birds' nest predation rates, and determined the relative importance of forested vegetation formations for the conservation of birds in the Pantanal. We estimated the apparent nesting success, and the abundance and richness of nesting birds' in four forest types, by monitoring nests during two reproductive seasons in four forested physiognomies (two high productivity/heterogeneity evergreen forests = Cambará and Landi; two low productivity/heterogeneity dry forests = Cordilheira and Carvoeiro) in the Pantanal wetland in Poconé, State of Mato Grosso, Brazil. We found 381 nests of 46 species (35 Passeriformes and 11 non-Passeriformes) in the four forest types. Of these, we monitored 220 active nests belonging to 44 species, 101 during the reproductive season of 2001 and 119 in 2002. We supported the productivity/heterogeneity hypothesis since the two evergreen forests had higher nest abundance and one of them (Cambará) had higher nesting species richness than the dry forests. The number of nests found in each habitat differed with most nests monitored in the Cambará forest (82%), followed by Landi (9%), Cordilheira (6%) and Carvoeiro (3%) forests. The total number of nests monitored was significantly higher in evergreen forests than in dry forests. Also, more species nested in evergreen (37 species) than in dry (16 species) forests. A Correspondence Analysis revealed that only Carvoeiros had a different nesting bird community. The overall apparent nesting success of 220 nests was 26.8%. We did not support the vegetation density hypothesis since nest predation rates were similar between evergreen (73.5%) and dry (70%) forests, and were higher in the Landi (85%) than in the other three forests (69.2 to 72.2%). Our data indicate that Cambará forests seem to be a key nesting habitat for many bird species of the

  19. Topographic Variation in Aboveground Biomass in a Subtropical Evergreen Broad-Leaved Forest in China

    PubMed Central

    Lin, Dunmei; Lai, Jiangshan; Muller-Landau, Helene C.; Mi, Xiangcheng; Ma, Keping

    2012-01-01

    The subtropical forest biome occupies about 25% of China, with species diversity only next to tropical forests. Despite the recognized importance of subtropical forest in regional carbon storage and cycling, uncertainties remain regarding the carbon storage of subtropical forests, and few studies have quantified within-site variation of biomass, making it difficult to evaluate the role of these forests in the global and regional carbon cycles. Using data for a 24-ha census plot in east China, we quantify aboveground biomass, characterize its spatial variation among different habitats, and analyse species relative contribution to the total aboveground biomass of different habitats. The average aboveground biomass was 223.0 Mg ha−1 (bootstrapped 95% confidence intervals [217.6, 228.5]) and varied substantially among four topographically defined habitats, from 180.6 Mg ha−1 (bootstrapped 95% CI [167.1, 195.0]) in the upper ridge to 245.9 Mg ha−1 (bootstrapped 95% CI [238.3, 253.8]) in the lower ridge, with upper and lower valley intermediate. In consistent with our expectation, individual species contributed differently to the total aboveground biomass of different habitats, reflecting significant species habitat associations. Different species show differently in habitat preference in terms of biomass contribution. These patterns may be the consequences of ecological strategies difference among different species. Results from this study enhance our ability to evaluate the role of subtropical forests in the regional carbon cycle and provide valuable information to guide the protection and management of subtropical broad-leaved forest for carbon sequestration and carbon storage. PMID:23118961

  20. Topographic variation in aboveground biomass in a subtropical evergreen broad-leaved forest in China.

    PubMed

    Lin, Dunmei; Lai, Jiangshan; Muller-Landau, Helene C; Mi, Xiangcheng; Ma, Keping

    2012-01-01

    The subtropical forest biome occupies about 25% of China, with species diversity only next to tropical forests. Despite the recognized importance of subtropical forest in regional carbon storage and cycling, uncertainties remain regarding the carbon storage of subtropical forests, and few studies have quantified within-site variation of biomass, making it difficult to evaluate the role of these forests in the global and regional carbon cycles. Using data for a 24-ha census plot in east China, we quantify aboveground biomass, characterize its spatial variation among different habitats, and analyse species relative contribution to the total aboveground biomass of different habitats. The average aboveground biomass was 223.0 Mg ha(-1) (bootstrapped 95% confidence intervals [217.6, 228.5]) and varied substantially among four topographically defined habitats, from 180.6 Mg ha(-1) (bootstrapped 95% CI [167.1, 195.0]) in the upper ridge to 245.9 Mg ha(-1) (bootstrapped 95% CI [238.3, 253.8]) in the lower ridge, with upper and lower valley intermediate. In consistent with our expectation, individual species contributed differently to the total aboveground biomass of different habitats, reflecting significant species habitat associations. Different species show differently in habitat preference in terms of biomass contribution. These patterns may be the consequences of ecological strategies difference among different species. Results from this study enhance our ability to evaluate the role of subtropical forests in the regional carbon cycle and provide valuable information to guide the protection and management of subtropical broad-leaved forest for carbon sequestration and carbon storage.

  1. Rainfall Reduction Increases Soil Methane Uptake in Broadleaf Evergreen Eucalypt Forest - a Negative Feedback to Climate Change

    NASA Astrophysics Data System (ADS)

    Fest, B. J.; Hinko-Najera, N.; Livesley, S. J.; Arndt, S. K.

    2013-12-01

    Well-drained aerated soils are important sinks for atmospheric methane (CH4), a process driven by CH4 oxidation through methanotrophic bacteria. Soils in temperate forest ecosystems represent the greatest terrestrial CH4 sink and soil moisture is one of the key regulators of soil CH4 flux in these systems. Most climate change models predict a decrease in average rainfall, an increase in extreme rainfall events and an increase in temperatures for mid-latitude and sub-arid regions. However, most studies of soil CH4 flux under altered rainfall scenarios have been conducted in mid-latitude forest and grassland systems of the northern hemisphere or in tropical forest systems and have often investigated extended drought rather than an reduction in long-term average rainfall. We measured soil CH4 flux for 18 months (October 2010 - April 2012) after installing a passive rainfall reduction system to intercept approximately 40% of canopy throughfall (as compared to control plots) in a temperate broadleaf evergreen eucalypt forest in south-eastern Australia. Throughfall reduction caused an average reduction of 15.1 × 6.4 (SE) % in soil volumetric water content, a reduction of 19.8 × 6.9 (SE) % in soil water filled pore space (WFPS) and a 20.1 × 6.8 (SE) % increase in soil air filled porosity (AFP). In response to these changes, soil CH4 uptake increased by 54.7 × 19.8 (SE) %. Relative changes in CH4 uptake related better to relative changes in AFP than to relative changes in WFPS, indicating a close relationship between AFP and soil gas diffusivity. Our data indicated that soil moisture was the dominant regulating factor of seasonality in soil CH4 uptake explaining up to 80% of the seasonal variability and accounting for the observed throughfall reduction treatment effect. This was confirmed by additional soil diffusivity measurements and passive soil warming treatments. We investigated non-linear functions to describe the relationship between soil moisture and soil CH4

  2. Species and stand traits of broadleaf deciduous and evergreen trees and its role on hydrologic processes in a semiarid forest

    NASA Astrophysics Data System (ADS)

    Arredondo, T.; Perez Suarez, M.; Rodriguez Robles, U.

    2013-05-01

    Empirical and modelling studies have pointed out to the importance of morphologic, physiologic and chemical traits of plant species on the control of functional aspects of ecosystems. Land use change exerts a pervasive effect on ecosystems through its effects on plant cover, species composition and the arrangement of vegetation. Species footprint influence on ecosystem processes occurs through their functional plant traits, understanding their role might be possible to predict alterations in ecosystem functioning. Using the concept of functional matrix we examined how traits of two dominant forest species, one broadleaf (Quercus potosina) and one evergreen (Pinus cembroides) observed as mixed and monospecific stands, exerted an influence on ecohydrological processes. Thus, differences in plant height, canopy structure, litter production and quality, root system distribution, etc. determined differences in vertical and horizontal rain fluxes. Oak monospecif stands showed 20% higher throughfall compared to mixex and pure pine stands as a consequence of exhibiting a monolayered canopy. On the other hand, runoff was 67 and 33 % in pine compared to oak and mixed stands a result that arosing from observed differences in litter decomposition stage as well as its proportion. Differences between root systems accounted for less negative plant water potentials in oak in contrast to pine. These differences together with leaf phenology allowed oak trees to reduce the plant water potential during the drought period. Similar pattern observed for pine is attributed to foraging capabilities of an extensive root system.

  3. [Composition and characteristics of understory bird communities in monsoon evergreen broadleaved forest of Mengyang, Xishuangbanna in the dry season].

    PubMed

    Huang, Jun-Hui; Zou, Fa-Sheng

    2010-06-01

    Understory birds in monsoon evergreen broadleaved forest of Mengyang, Xishuangbanna, Yunnan were sampled using mist nets from October 2008 to March 2009. A total of 1423 individuals of 90 species belonging to 28 families and 7 orders were captured, among which there are 8 dominant bird species, i.e., Sliver-breasted Broadbill (Serilophus lunatus), Brown-cheeked Fulvatta (Alcippe poioicephala), White-throated Bulbul (Alophoixus pallidus), Golden-spectacled Warbler (Seicercus burkii), White-tailed Robin (Cinclidium leucurum), Black-breasted Thrush (Turdus dissimilis), Streak-Breasted Jungle Babbler (Pellorneum ruficeps), and Buff-breasted Jungle Babbler (Trichastoma tickelli). Resident birds, the major composition of the understory birds, accounted for 89.3 percent of total captures. The mean capture rate was 9.0+-3.7 individuals/(100 net-hours) and it differed significantly between months, highest in December 2008 (12.5+-1.3)individuals/(100 net-hours), lowest in February 2009 (5.2+-0.6) individuals/(100 net-hours). The most significant characteristic of understory birds in Xishuangbanna is more species abundance and lower species density compared to understory bird composition of South China. Another characteristic is that no obvious dominance pattern was observed in Babbler species. We also noticed that silver-breasted Broadbill, National Key Protection Bird, is the most abundance species in our captures, thus their habitat require further protection.

  4. Evergreen broadleaf forest transition zone changes in Japan from 1961 to 2008 detected by aerial ortho-photos

    NASA Astrophysics Data System (ADS)

    Nakazono, Etsuko; Tanaka, Nobuyuki; Yasuda, Masatsugu; Daimaru, Hiromu; Takeuchi, Wataru

    2016-06-01

    In order to detect the distribution change of evergreen broad-leaved trees (EBTs) in a old-growth forest on the transitional zone of cool-temperate and warm-temperate zones, we used the ortho-photo data conversed from the aerial photos. Comparing the crown map of EBTs in the 1-ha verification plot with the ground truth data of individual tree inventory, 14 out of 17 (82%) upper layer trees were found to be visually read on the aerial photo We chose two indices for detecting the distribution change of EBTs, crown number and total crown area. We made crown maps of the 20-ha plot based on ortho-photos in 1961, 1975, 1985, 2003, 2005 and 2008, and calculated crown number and total crown area for each photos. The crown number increased at a rate 0.18/year/ha from 1961 to 2000’s, and total crown area also increased at a rate 0.21% for the 20-ha plot. The total crow area increase was highly probable because errors of area in orthophotos were smaller than secular changes of the area.

  5. [Plant biodiversity and community structure of semi-humid evergreen broadleaved forests at different secondary succession stages].

    PubMed

    Wang, Zhenhong; Duan, Changqun; Yang, Jiansong

    2006-09-01

    To analyze the relationships between plant diversity and community structure of semi-humid evergreen broadleaved forests at different secondary succession stage in the Samachang area of Yunnan Province, some numeral indices were tested, and the results showed that the plant diversity increased gradually with succession, and the species number reached 24 at the latest succession stage. There was a positive linear correlation between plant individual density and species diversity, which could be described by y = 506. 99x + 554.56. A negative correlation was observed between the average height of plant individuals and plant species diversity, and the equation y = -0. 3862x + 11.406 could describe it well. The crown density and basal area increased in logarithm with plant species diversity, and the two equations y = 21.756 1n x + 11.607 and y = 7.4028 ln x + 9.6198 could describe the relations. No regular patterns were observed for the changes of aboveground biomass and plant individual density with plant species diversity. The relations of plant species with plant individual number could also be described by negative power function. Plant competition was intensified with plant species diversity, and each plant species might take the strategy to conserve its greatest population, and to avoid decreasing to less than its critical population, which led to a high individual density, and might change the structural character of the community.

  6. Physiological basis of seasonal trend in leaf photosynthesis of five evergreen broad-leaved species in a temperate deciduous forest.

    PubMed

    Miyazawa, Yoshiyuki; Kikuzawa, Kihachiro

    2006-02-01

    The physiological basis of photosynthesis during winter was investigated in saplings of five evergreen broad-leaved species (Camellia japonica L., Cleyera japonica Thunb., Photinia glabra (Thunb.) Maxim., Castanopsis cuspidata (Thunb.) Schottky and Quercus glauca Thunb.) co-occurring under deciduous canopy trees in a temperate forest. We focused on temperature dependence of photosynthetic rate and capacity as important physiological parameters that determine light-saturated rates of net photosynthesis at low temperatures during winter. Under controlled temperature conditions, maximum rates of ribulose bisphosphate carboxylation and electron transport (Vcmax) and Jmax, respectively) increased exponentially with increasing leaf temperature. The temperature dependence of photosynthetic rate did not differ among species. In the field, photosynthetic capacity, determined as Vcmax and Jmax at a common temperature of 25 degrees C (Vcmax(25) and Jmax(25)), increased until autumn and then decreased in species-specific patterns. Values of Vcmax(25) and Jmax(25) differed among species during winter. There was a positive correlation of Vcmax(25) with area-based nitrogen concentration among leaves during winter in Camellia and Photinia. Interspecific differences in Vcmax(25) were responsible for interspecific differences in light-saturated rates of net photosynthesis during winter.

  7. Forest type influences transmission of Phytophthora ramorum in California oak woodlands

    Treesearch

    J. M. Davidson; H. A. Patterson; A. C. Wickland; E. J. Fichtner; D. M. Rizzo

    2011-01-01

    The transmission ecology of Phytophthora ramorum from bay laurel (Umbellularia californica) leaves was compared between mixed-evergreen and redwood forest types throughout winter and summer disease cycles in central, coastal California. In a preliminary multisite study, we found that abscission rates of infected leaves were higher at mixed...

  8. Modeling gross primary production of an evergreen needleleaf forest using MODIS and climate data

    Treesearch

    Xiangming Xiao; Qingyuan Zhang; David Hollinger; John Aber; Berrien, III Moore

    2005-01-01

    Forest canopies are composed of photosynthetically active vegetation (PAV, chloroplasts) and nonphotosynthetic vegetation (NPV, e.g., cell wall, vein, branch). The fraction of photosynthetically active radiation (PAR) absorbed by the canopy (FAPAR) should be partitioned into FAPARPAV and FAPARNPV. Gross primary production (...

  9. Phylogenetic Structure of Tree Species across Different Life Stages from Seedlings to Canopy Trees in a Subtropical Evergreen Broad-Leaved Forest.

    PubMed

    Jin, Yi; Qian, Hong; Yu, Mingjian

    2015-01-01

    Investigating patterns of phylogenetic structure across different life stages of tree species in forests is crucial to understanding forest community assembly, and investigating forest gap influence on the phylogenetic structure of forest regeneration is necessary for understanding forest community assembly. Here, we examine the phylogenetic structure of tree species across life stages from seedlings to canopy trees, as well as forest gap influence on the phylogenetic structure of forest regeneration in a forest of the subtropical region in China. We investigate changes in phylogenetic relatedness (measured as NRI) of tree species from seedlings, saplings, treelets to canopy trees; we compare the phylogenetic turnover (measured as βNRI) between canopy trees and seedlings in forest understory with that between canopy trees and seedlings in forest gaps. We found that phylogenetic relatedness generally increases from seedlings through saplings and treelets up to canopy trees, and that phylogenetic relatedness does not differ between seedlings in forest understory and those in forest gaps, but phylogenetic turnover between canopy trees and seedlings in forest understory is lower than that between canopy trees and seedlings in forest gaps. We conclude that tree species tend to be more closely related from seedling to canopy layers, and that forest gaps alter the seedling phylogenetic turnover of the studied forest. It is likely that the increasing trend of phylogenetic clustering as tree stem size increases observed in this subtropical forest is primarily driven by abiotic filtering processes, which select a set of closely related evergreen broad-leaved tree species whose regeneration has adapted to the closed canopy environments of the subtropical forest developed under the regional monsoon climate.

  10. Phylogenetic Structure of Tree Species across Different Life Stages from Seedlings to Canopy Trees in a Subtropical Evergreen Broad-Leaved Forest

    PubMed Central

    Jin, Yi; Qian, Hong; Yu, Mingjian

    2015-01-01

    Investigating patterns of phylogenetic structure across different life stages of tree species in forests is crucial to understanding forest community assembly, and investigating forest gap influence on the phylogenetic structure of forest regeneration is necessary for understanding forest community assembly. Here, we examine the phylogenetic structure of tree species across life stages from seedlings to canopy trees, as well as forest gap influence on the phylogenetic structure of forest regeneration in a forest of the subtropical region in China. We investigate changes in phylogenetic relatedness (measured as NRI) of tree species from seedlings, saplings, treelets to canopy trees; we compare the phylogenetic turnover (measured as βNRI) between canopy trees and seedlings in forest understory with that between canopy trees and seedlings in forest gaps. We found that phylogenetic relatedness generally increases from seedlings through saplings and treelets up to canopy trees, and that phylogenetic relatedness does not differ between seedlings in forest understory and those in forest gaps, but phylogenetic turnover between canopy trees and seedlings in forest understory is lower than that between canopy trees and seedlings in forest gaps. We conclude that tree species tend to be more closely related from seedling to canopy layers, and that forest gaps alter the seedling phylogenetic turnover of the studied forest. It is likely that the increasing trend of phylogenetic clustering as tree stem size increases observed in this subtropical forest is primarily driven by abiotic filtering processes, which select a set of closely related evergreen broad-leaved tree species whose regeneration has adapted to the closed canopy environments of the subtropical forest developed under the regional monsoon climate. PMID:26098916

  11. Taxonomy, Traits, and Environment Determine Isoprenoid Emission from an Evergreen Tropical forest.

    NASA Astrophysics Data System (ADS)

    Taylor, T.; Alves, E. G.; Tota, J.; Oliveira Junior, R. C.; Camargo, P. B. D.; Saleska, S. R.

    2016-12-01

    Volatile isoprenoid emissions from the leaves of tropical forest trees significantly affects atmospheric chemistry, aerosols, and cloud dynamics, as well as the physiology of the emitting leaves. Emission is associated with plant tolerance to heat and drought stress. Despite a potentially central role of isoprenoid emissions in tropical forest-climate interactions, we have a poor understanding of the relationship between emissions and ecological axes of forest function. We used a custom instrument to quantify leaf isoprenoid emission rates from over 200 leaves and 80 trees at a site in the eastern Brazilian Amazon. We related standardized leaf emission capacity (EC: leaf emission rate at 1000 PAR) to tree taxonomy, height, light environment, wood traits, and leaf traits. Taxonomy was the strongest predictor of EC, and non-emitters could be found throughout the canopy. But we found that environment and leaf carbon economics constrained the upper bound of EC. For example, the relationship between EC and specific leaf area (SLA; fresh leaf area / dry mass) is described by an envelope with a decreasing upper bound on EC as SLA increases (quantile regression: 85th quantile, p<0.01). That result suggests a limitation on emissions related to leaf carbon investment strategies. EC was highest in the mid-canopy, and in leaves growing under less direct light. While inferences of ecosystem emissions focus on environmental conditions in the canopy, our results suggest that sub-canopy leaves are more responsive. This work is allowing us to develop an ecological understanding of isoprenoid emissions from forests, the basis for a predictive model of emissions that depends on both environmental factors and biological emission capacity that is grounded in plant traits and phylogeny.

  12. Quantitative study on nitrogen deposition and canopy retention in Mediterranean evergreen forests.

    PubMed

    Avila, Anna; Aguillaume, Laura; Izquieta-Rojano, Sheila; García-Gómez, Héctor; Elustondo, David; Santamaría, Jesús Miguel; Alonso, Rocío

    2017-04-06

    To assess the impact of nitrogen (N) pollutants on forest ecosystems, the role of the interactions in the canopy needs to be understood. A great number of studies have addressed this issue in heavily N-polluted regions in north and central Europe. Much less information is available for the Iberian Peninsula, and yet this region is home to mountain forests and alpine grasslands that may be at risk due to excessive N deposition. To establish the basis for ecology-based policies, there is a need to better understand the forest response to this atmospheric impact. To fill this gap, in this study, we measured N deposition (as bulk, wet, and throughfall fluxes of dissolved inorganic nitrogen) and air N gas concentrations from 2011 to 2013 at four Spanish holm oak (Quercus ilex) forests located in different pollution environments. One site was in an area of intensive agriculture, two sites were influenced by big cities (Madrid and Barcelona, respectively), and one site was in a rural mountain environment 40 km north of Barcelona. Wet deposition ranged between 0.54 and 3.8 kg N ha(-1) year(-1) for ammonium (NH4(+))-N and between 0.65 and 2.1 kg N ha(-1) year(-1) for nitrate (NO3(-))-N, with the lowest deposition at the Madrid site for both components. Dry deposition was evaluated with three different approaches: (1) a canopy budget model based in throughfall measurements, (2) a branch washing method, and (3) inferential calculations. Taking the average dry deposition from these methods, dry deposition represented 51-67% (reduced N) and 72-75% (oxidized N) of total N deposition. Canopies retained both NH4(+)-N and NO3-N, with a higher retention at the agricultural and rural sites (50-60%) than at sites located close to big cities (20-35%, though more uncertainty was found for the site near Madrid), thereby highlighting the role of the forest canopy in processing N pollutant emissions.

  13. 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.

  14. 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

  15. Modelling the climatic drivers determining photosynthesis and carbon allocation in evergreen Mediterranean forests using multiproxy long time series

    NASA Astrophysics Data System (ADS)

    Gea-Izquierdo, G.; Guibal, F.; Joffre, R.; Ourcival, J. M.; Simioni, G.; Guiot, J.

    2015-06-01

    Climatic drivers limit several important physiological processes involved in ecosystem carbon dynamics including gross primary productivity (GPP) and carbon allocation in vegetation. Climatic variability limits these two processes differently. We developed an existing mechanistic model to analyse photosynthesis and variability in carbon allocation in two evergreen species at two Mediterranean forests. The model was calibrated using a combination of eddy covariance CO2 flux data, dendrochronological time series of secondary growth and forest inventory data. The model was modified to be climate explicit in the key processes addressing the acclimation of photosynthesis and the pattern of C allocation, particularly to water stress. It succeeded in fitting both the high- and the low-frequency response of stand GPP and carbon allocation to stem growth. This would support its capability to address both C-source and C-sink limitations. Simulations suggest a decrease in mean stomatal conductance in response to a recent enhancement in water stress and an increase in mean annual intrinsic water use efficiency (iWUE) in both species during the last 50 years. However, this was not translated into a parallel increase in ecosystem water use efficiency (WUE). The interannual variability in WUE closely followed that in iWUE at both sites. Nevertheless, long-term decadal variability in WUE followed the long-term decrease in annual GPP matching the local trend in annual precipitation observed since the late 1970s at one site. In contrast, at the site where long-term precipitation remained stable, GPP and WUE did not show a negative trend and the trees buffered the climatic variability. In our simulations these temporal changes were related to acclimation processes at the canopy level, including modifications in LAI and stomatal conductance, but also partly related to increasing [CO2] because the model includes biochemical equations where photosynthesis is directly linked to [CO2

  16. Partitioning the climatic and biological controls on photosynthetic fluxes in Amazonian tropical evergreen forests

    NASA Astrophysics Data System (ADS)

    Wu, J.; Guan, K.; Albert, L.; Hayek, M.; Restrepo-Coupe, N.; Prohaska, N.; Wiedemann, K. T.; Marostica, S. F.; Stark, S. C.; Smith, M.; Silva, R. D.; Dye, D. G.; Nelson, B. W.; Huete, A. R.; Saleska, S. R.

    2014-12-01

    Understanding the mechanistic controls on tropical forests photosynthetic metabolism is a central problem of ecology and global change biology. We hypothesize two different temporal scales for the mechanisms regulating tropical photosynthesis (Gross Ecosystem Productivity, GEP): (1) at seasonal scales, leaf phenology (changing age and amount of leaves) is the primary control on GEP seasonality; (2) at the hourly scale with a constant phenological stage, climatic variables are the first order controls on GEP. In order to test this hypothesis, we partitioned the sources of GEP variation measured on eddy flux towers in central Amazon forests into biological and climatic components. The biological component (photosynthetic capacity, or PC) was defined as the monthly mean value of GEP extracted under a fixed narrow range of climate conditions, representing phenological changes associated with the amount and age of leaves. The climatic component was extracted via a path analysis of the hourly flux data, conditioned on a given monthly PC, representing the effects of fluctuating climate operating on the given PC. The main climatic variables were PAR, air-temperature, VPD, and Cloudiness Index (CI), the fraction of reduction of incident solar radiance due to clouds and aerosols relative to that expected under clear sky conditions. We found that the variability in monthly GEP arises from both seasonality of PC and that of climate, but despite the strong seasonality of climate, GEP was dominated by PC seasonality (R2=0.92). We found that the variability in hourly GEP (relative to the potential represented by monthly PC) was controlled primarily by PAR and VPD (as modified by the influence of CI). The tradeoff between the positive GEP effects of increased PAR and the negative effects of higher VPD stress indicates that tropical forests are stable in the face of modest climatic variability. For example, a significant reduction in mean cloudiness (of 0.1 CI units, corresponding

  17. Genetic structure of Camellia japonica L. in an old-growth evergreen forest, Tsushima, Japan.

    PubMed

    Ueno, S; Tomaru, N; Yoshimaru, H; Manabe, T; Yamamoto, S

    2000-06-01

    The spatial genetic structure of Camellia japonica was investigated, using microsatellite markers, in a 4-ha permanent plot within an old-growth forest. Spatial distribution of individuals was also assessed to obtain an insight into spatial relationships between individuals and alleles. Morisita's index of dispersion showed that 518 C. japonica individuals in the plot were clumped, and Moran's I spatial autocorrelation coefficient revealed weak genetic structure, indicating a low level of allele clustering. Average I correlograms showed that there was stronger genetic structure over short-distance classes. The clumped distribution of individuals and the positive autocorrelation over short-distance classes may result from the limited seed dispersal and microsite heterogeneity of the stand, while the genetic structure may be weakened by overlapping seed shadow and extensive pollen flow, mediated by animal vectors, and the high outcrossing rate found in C. japonica.

  18. Simulations of water and heat exchanges for a subtropical mixed evergreen forest with BATS2 and SHAW

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Wu, B.; Li, M.

    2010-12-01

    In this study, the water and energy exchanges between land surface and atmosphere were simulated by BATS2 and SHAW for a subtropical mixed evergreen forest (the Lien-Hua-Chih site) with continuous measurements of hydrological and micrometeorological variables, and eddy covariance fluxes. The BATS2 (Dickinson et al. 1998) model is the second version of BATS (Biosphere-Atmosphere Transfer Scheme). The BATSs are typical land surface models frequently used by atmospheric research communities to study land surface processes. A bulk canopy layer (Big leaf assumption) is parameterized to control the water flux from the root zone to the atmosphere by a stomatal conductance model limited by soil moisture, CO¬2 concentration, and micrometeorological factors. The SHAW (Simultaneous Heat And Water; Flerchinger, 2000) model, originally developed to simulate soil freezing and thawing (Flerchinger and Saxton, 1989), can simultaneously simulate heat, water, and solute transfer within a layered system of plant canopy, snowpack, dead plant residue, soil frost, and underlying soil. The model can be applied to assess management and climate effects on various biological and hydrological processes. Although the original applications of BATS2 and SHAW are not quite the same, both models are capable of simulating water and energy exchanges between land surface and atmosphere. Root zone moisture contents computed by BATS2 and the corresponding layers of soil moistures by SHAW were compared with field measurements of soil moisture on daily to seasonal scales. The soil moisture responses of SHAW are more sensitive to atmospheric forcing than those of BATS2 due to layered descriptions of underlying soils. Similar results were found on descriptions of soil temperatures. On the contrary, BATS2 is superior to SHAW on describing latent and sensible heat fluxes variations on the daily scales due to the sophisticated stomatal conductance model. However, the differences of surface fluxes on the

  19. Improving winter leaf area index estimation in evergreen coniferous forests and its significance in carbon and water fluxes modeling

    NASA Astrophysics Data System (ADS)

    Wang, R.; Chen, J. M.; Luo, X.

    2016-12-01

    Modeling of carbon and water fluxes at the continental and global scales requires remotely sensed LAI as inputs. For evergreen coniferous forests (ENF), severely underestimated winter LAI has been one of the issues for mostly available remote sensing products, which could cause negative bias in the modeling of Gross Primary Productivity (GPP) and evapotranspiration (ET). Unlike deciduous trees which shed all the leaves in winter, conifers retains part of their needles and the proportion of the retained needles depends on the needle longevity. In this work, the Boreal Ecosystem Productivity Simulator (BEPS) was used to model GPP and ET at eight FLUXNET Canada ENF sites. Two sets of LAI were used as the model inputs: the 250m 10-day University of Toronto (U of T) LAI product Version 2 and the corrected LAI based on the U of T LAI product and the needle longevity of the corresponding tree species at individual sites. Validating model daily GPP (gC/m2) against site measurements, the mean RMSE over eight sites decreases from 1.85 to 1.15, and the bias changes from -0.99 to -0.19. For daily ET (mm), mean RMSE decreases from 0.63 to 0.33, and the bias changes from -0.31 to -0.16. Most of the improvements occur in the beginning and at the end of the growing season when there is large correction of LAI and meanwhile temperature is still suitable for photosynthesis and transpiration. For the dormant season, the improvement in ET simulation mostly comes from the increased interception of precipitation brought by the elevated LAI during that time. The results indicate that model performance can be improved by the application the corrected LAI. Improving the winter RS LAI can make a large impact on land surface carbon and energy budget.

  20. New foliage growth is a significant, unaccounted source for volatiles in boreal evergreen forests

    NASA Astrophysics Data System (ADS)

    Aalto, J.; Kolari, P.; Hari, P.; Kerminen, V.-M.; Schiestl-Aalto, P.; Aaltonen, H.; Levula, J.; Siivola, E.; Kulmala, M.; Bäck, J.

    2014-03-01

    Estimates of volatile organic compound (VOC) emissions from forests are based on the assumption that foliage has a steady emission potential over its lifetime, and that emissions are mainly modified by short-term variations in light and temperature. However, in many field studies this has been challenged, and high emissions and atmospheric concentrations have been measured during periods of low biological activity, such as in springtime. We conducted measurements during three years, using an online gas-exchange monitoring system to observe volatile organic emissions from a mature (1 year-old) and a growing Scots pine shoot. The emission rates of organic vapors from vegetative buds of Scots pine during the dehardening and rapid shoot growth stages were one to two orders of magnitude higher than those from mature foliage; this difference decreased and finally disappeared when the new shoot was maturing in late summer. On average, the springtime monoterpene emission rate of the bud was about 500 times higher than that of the mature needles; during the most intensive needle elongation period, the monoterpene emission rate of the growing needles was 3.5 higher than that of the mature needles, and in September the monoterpene emission rate of the same years' needles was even lower (50%) than that of the previous years' needles. For other measured compounds (methanol, acetone and methylbutenol) the values were of the same order of magnitude, except before bud break in spring, when the emission rates of buds for those compounds were on average about 20-30 times higher than that of mature needles. During spring and early summer the buds and growing shoots are a strong source of several VOCs, and if they are not accounted for in emission modeling a significant proportion of the emissions - from a few percent to even half of the annual cumulative emissions - will remain concealed. The diurnal emission pattern of growing shoots differed from the diurnal cycle in temperature as

  1. Modelling the drought impact on monoterpene fluxes from an evergreen Mediterranean forest canopy.

    PubMed

    Grote, Rüdiger; Lavoir, Anne-Violette; Rambal, Serge; Staudt, Michael; Zimmer, Ina; Schnitzler, Jörg-Peter

    2009-05-01

    In many ecosystems drought cycles are common during the growing season but their impact on volatile monoterpene emissions is unclear. Therefore, we aimed to develop and evaluate a process-based modelling approach to explore the explanatory power of likely mechanisms. The biochemically based isoprene and monoterpene emission model SIM-BIM2 has been modified and linked to a canopy model and a soil water balance model. Simulations are carried out for Quercus ilex forest sites and results are compared to measured soil water, photosynthesis, terpene-synthase activity, and monoterpene emission rates. Finally, the coupled model system is used to estimate the annual drought impact on photosynthesis and emission. The combined and adjusted vegetation model was able to simulate photosynthesis and monoterpene emission under dry and irrigated conditions with an R(2) of 0.74 and 0.52, respectively. We estimated an annual reduction of monoterpene emission of 67% for the extended and severe drought period in 2006 in the investigated Mediterranean ecosystem. It is concluded that process-based ecosystem models can provide a useful tool to investigate the involved mechanisms and to quantify the importance of specific environmental constraints.

  2. Forest stand dynamics and sudden oak death: Mortality in mixed-evergreen forests dominated by coast live oak

    Treesearch

    L.B. Brown; B. Allen-Diaz

    2009-01-01

    Sudden oak death (SOD), caused by the recently discovered non-native invasive pathogen, Phytophthora ramorum, has already killed tens of thousands of native coast live oak and tanoak trees in California. Little is known of potential short and long term impacts of this novel plant–pathogen interaction on forest structure and composition. Coast live...

  3. Carbon-Nitrogen Cycle Model of Terrestrial Ecosystem for Plot Scale: Application to Cool Temperate Deciduous Broad-leaved Forest and Cool Temperate Evergreen Coniferous Forest in Central Japan

    NASA Astrophysics Data System (ADS)

    Ito, A.; Inatomi, M.

    2007-12-01

    By developing a biogeochemical model that fully includes carbon cycle and nitrogen cycle in a single framework, we can consider nitrogen nutrition as a limiting elements in the model and evaluate atmosphere-ecosystem exchange of trace greenhouse gases in addition to carbon dioxide (i.e. methane and nitrous oxide). In this study, a process-based model simulating carbon-nitrogen cycle was developed and applied to a cool-temperate deciduous broad-leaved forest in Takayama (36N, 137E, 1420m ASL) and a cool-temperate evergreen coniferous forest in Fujiyoshida (35N, 138E, 1030m ASL), central Japan. Models of nitrogen cycle were introduced into a revised terrestrial ecosystem model Sim-CYCLE, which is a simple box-type carbon cycle model simulating net ecosystem CO2 exchange on the basis of ecophysiological relationships. Using the model, photosynthetic and respiratory CO2 fluxes were simulated during the periods from 1948 to 2004 at daily step using time-series climate data. On average during the last 10 years, the model estimated that the temperate forest absorbed net CO2 and CH4 at rates of 804.53 g CO2 m-2 yr-1 and 0.34 g CH4 m-2 yr-1, and net released N2O at a rate of 0.02 g N2O m-2 yr-1, respectively. Based on the 100-year GWP of greenhouse gases in IPCC (2001), the forest was estimated to have a negative (i.e. ameliorating) effect of GWP by 807.74 g CO2 (equivalent) m-2 yr-1. Because the results seem reasonable, we are working on scaling-up of the model to regional scale, in our forthcoming studies.

  4. Nationwide classification of forest types of India using remote sensing and GIS.

    PubMed

    Reddy, C Sudhakar; Jha, C S; Diwakar, P G; Dadhwal, V K

    2015-12-01

    India, a mega-diverse country, possesses a wide range of climate and vegetation types along with a varied topography. The present study has classified forest types of India based on multi-season IRS Resourcesat-2 Advanced Wide Field Sensor (AWiFS) data. The study has characterized 29 land use/land cover classes including 14 forest types and seven scrub types. Hybrid classification approach has been used for the classification of forest types. The classification of vegetation has been carried out based on the ecological rule bases followed by Champion and Seth's (1968) scheme of forest types in India. The present classification scheme has been compared with the available global and national level land cover products. The natural vegetation cover was estimated to be 29.36% of total geographical area of India. The predominant forest types of India are tropical dry deciduous and tropical moist deciduous. Of the total forest cover, tropical dry deciduous forests occupy an area of 2,17,713 km(2) (34.80%) followed by 2,07,649 km(2) (33.19%) under tropical moist deciduous forests, 48,295 km(2) (7.72%) under tropical semi-evergreen forests and 47,192 km(2) (7.54%) under tropical wet evergreen forests. The study has brought out a comprehensive vegetation cover and forest type maps based on inputs critical in defining the various categories of vegetation and forest types. This spatially explicit database will be highly useful for the studies related to changes in various forest types, carbon stocks, climate-vegetation modeling and biogeochemical cycles.

  5. Physiological and morphological responses to permanent and intermittent waterlogging in seedlings of four evergreen trees of temperate swamp forests.

    PubMed

    Zúñiga-Feest, Alejandra; Bustos-Salazar, Angela; Alves, Fernanda; Martinez, Vanessa; Smith-Ramírez, Cecilia; Pereira, Joào

    2017-03-14

    Waterlogging decreases a plant's metabolism, stomatal conductance (gs) and photosynthetic rate (A); however, some evergreen species show acclimation to waterlogging. By studying both the physiological and morphological responses to waterlogging, the objective of this study was to assess the acclimation capacity of four swamp forest species that reside in different microhabitats. We proposed that species (Luma apiculata [D.C.] Burret. and Drimys winteri J.R. et G. Forster.) abundant in seasonally and intermittently waterlogged areas (SIWA) would have a higher acclimation capacity than species abundant in the inner swamp (Blepharocalyx cruckshanksii [H et A.] Mied. and Myrceugenia exsucca [D.C.] Berg.) where permanent waterlogging occurs (PWA); it was expected that the species from SIWA would maintain leaf expansion and gas exchange rates during intermittent waterlogging treatments. Conversely, we expected that PWA species would have higher constitutive waterlogging tolerance, and this would be reflected in the formation of lenticels and adventitious roots. Over the course of 2 months, we subjected seedlings to different waterlogging treatments: (i) permanent (sudden, SW), (ii) intermittent (gradual) or (iii) control (field capacity, C). Survival after waterlogging was high (≥80%) for all species and treatments, and only the growth rate of D. winteri subjected to SW was affected. Drimys winteri plants had low, but constant A and g during both waterlogging treatments. Conversely, L. apiculata had the highest A and g values, and g increased significantly during the first several days of waterlogging. In general, seedlings of all species subjected to waterlogging produced more adventitious roots and fully expanded leaves and had higher specific leaf area (SLA) and stomatal density (StD) than seedlings in the C treatment. From the results gathered here, we partially accept our hypothesis as all species showed high tolerance to waterlogging, maintained growth, and had

  6. Forest habitat types of Montana

    Treesearch

    Robert D. Pfister; Bernard L. Kovalchik; Stephen F. Arno; Richard C. Presby

    1977-01-01

    A land-classification system based upon potential natural vegetation is presented for the forests of Montana. It is based on an intensive 4-year study and reconnaissance sampling of about 1,500 stands. A hierarchical classification of forest sites was developed using the habitat type concept. A total of 9 climax series, 64 habitat types, and 37 additional phases of...

  7. Vegetation Response and Landscape Dynamics of Indian Summer Monsoon Variations during Holocene: An Eco-Geomorphological Appraisal of Tropical Evergreen Forest Subfossil Logs

    PubMed Central

    Kumaran, Navnith K. P.; Padmalal, Damodaran; Nair, Madhavan K.; Limaye, Ruta B.; Guleria, Jaswant S.; Srivastava, Rashmi; Shukla, Anumeha

    2014-01-01

    The high rainfall and low sea level during Early Holocene had a significant impact on the development and sustenance of dense forest and swamp-marsh cover along the southwest coast of India. This heavy rainfall flooded the coastal plains, forest flourishing in the abandoned river channels and other low-lying areas in midland.The coastline and other areas in lowland of southwestern India supply sufficient evidence of tree trunks of wet evergreen forests getting buried during the Holocene period under varying thickness of clay, silty-clay and even in sand sequences. This preserved subfossil log assemblage forms an excellent proxy for eco-geomorphological and palaeoclimate appraisal reported hitherto from Indian subcontinent, and complements the available palynological data. The bulk of the subfossil logs and partially carbonized wood remains have yielded age prior to the Holocene transgression of 6.5 k yrs BP, suggesting therein that flooding due to heavy rainfall drowned the forest cover, even extending to parts of the present shelf. These preserved logs represent a unique palaeoenvironmental database as they contain observable cellular structure. Some of them can even be compared to modern analogues. As these woods belong to the Late Pleistocene and Holocene, they form a valuable source of climate data that alleviates the lack of contemporaneous meteorological records. These palaeoforests along with pollen proxies depict the warmer environment in this region, which is consistent with a Mid Holocene Thermal Maximum often referred to as Holocene Climate Optimum. Thus, the subfossil logs of tropical evergreen forests constitute new indices of Asian palaeomonsoon, while their occurrence and preservation are attributed to eco-geomorphology and hydrological regimes associated with the intensified Asian Summer Monsoon, as recorded elsewhere. PMID:24727672

  8. Vegetation response and landscape dynamics of Indian Summer Monsoon variations during Holocene: an eco-geomorphological appraisal of tropical evergreen forest subfossil logs.

    PubMed

    Kumaran, Navnith K P; Padmalal, Damodaran; Nair, Madhavan K; Limaye, Ruta B; Guleria, Jaswant S; Srivastava, Rashmi; Shukla, Anumeha

    2014-01-01

    The high rainfall and low sea level during Early Holocene had a significant impact on the development and sustenance of dense forest and swamp-marsh cover along the southwest coast of India. This heavy rainfall flooded the coastal plains, forest flourishing in the abandoned river channels and other low-lying areas in midland.The coastline and other areas in lowland of southwestern India supply sufficient evidence of tree trunks of wet evergreen forests getting buried during the Holocene period under varying thickness of clay, silty-clay and even in sand sequences. This preserved subfossil log assemblage forms an excellent proxy for eco-geomorphological and palaeoclimate appraisal reported hitherto from Indian subcontinent, and complements the available palynological data. The bulk of the subfossil logs and partially carbonized wood remains have yielded age prior to the Holocene transgression of 6.5 k yrs BP, suggesting therein that flooding due to heavy rainfall drowned the forest cover, even extending to parts of the present shelf. These preserved logs represent a unique palaeoenvironmental database as they contain observable cellular structure. Some of them can even be compared to modern analogues. As these woods belong to the Late Pleistocene and Holocene, they form a valuable source of climate data that alleviates the lack of contemporaneous meteorological records. These palaeoforests along with pollen proxies depict the warmer environment in this region, which is consistent with a Mid Holocene Thermal Maximum often referred to as Holocene Climate Optimum. Thus, the subfossil logs of tropical evergreen forests constitute new indices of Asian palaeomonsoon, while their occurrence and preservation are attributed to eco-geomorphology and hydrological regimes associated with the intensified Asian Summer Monsoon, as recorded elsewhere.

  9. Valuation of spatial configurations and forest types in the southern appalachian highlands.

    PubMed

    Cho, Seong-Hoon; Jung, Suhyun; Kim, Seung Gyu

    2009-04-01

    Site-specific estimates of the values of spatial configuration and forest composition are presented. Amenity values of forest patches are found to vary the most by urban and sprawling development patterns of specific areas and forest types. For example, smaller patches of deciduous forest are more highly valued in the urban and sprawling areas of Greensboro, North Carolina, whereas larger patches of deciduous forest are more highly valued in the urban and sprawling areas of Greenville, South Carolina. Within the Greenville and Greensboro areas, visible landscape complexity is highly valued for deciduous and evergreen forest patches, whereas lower visible landscape complexity, i.e., smoothly trimmed forest patch boundaries, is highly valued for mixed forest patches.

  10. Seasonal fluctuations and temperature dependence of leaf gas exchange parameters of co-occurring evergreen and deciduous trees in a temperate broad-leaved forest.

    PubMed

    Kosugi, Yoshiko; Matsuo, Naoko

    2006-09-01

    Seasonal fluctuations in leaf gas exchange parameters were investigated in three evergreen (Quercus glauca Thunb., Cinnamomum camphora Sieb. and Castanopsis cuspidata Schottky) and one deciduous (Quercus serrata Thunb.) co-occurring, dominant tree species in a temperate broad-leaved forest. Dark respiration rate (Rn), maximum carboxylation rate (Vcmax) and stomatal coefficient (m), the ratio of stomatal conductance to net assimilation rate after adjustment to the vapor pressure deficit and internal carbon dioxide (CO2) concentration, were derived inversely from instantaneous field gas exchange data (one-point method). The normalized values of Rn and Vcmax at the reference temperature of 25 degrees C (Rn25, Vcmax25) and their temperature dependencies (Delta Ha(Rn), Delta Ha(Vcmax)) were analyzed. Parameter Vcmax25 ranged from 24.0-40.3 micromol m(-2) s(-1) and Delta Ha(Vcmax) ranged from 29.1- 67.0 kJ mol(-1). Parameter Rn25 ranged from 0.6-1.4 micromol m(-2) s(-1) and Delta Ha(Rn) ranged from 47.4-95.4 kJ mol(-1). The stomatal coefficient ranged from 7.2-8.2. For the three evergreen trees, a single set of Vcmax25 and Rn25 parameters and temperature dependence curves produced satisfactory estimates of carbon uptake throughout the year, except during the period of simultaneous leaf fall and leaf expansion, which occurs in April and May. In the deciduous oak, declines in Vcmax25 were observed after summer, along with changes in Vcmax25 and Rn25 during the leaf expansion period. In all species, variation in m during periods of leaf expansion and drought should be considered in modeling studies. We conclude that the changes in normalized gas exchange parameters during periods of leaf expansion and drought need to be considered when modeling carbon uptake of evergreen broad-leaved species.

  11. Plant functional types are more efficient than climate in predicting spectrums of trait variation in evergreen angiosperm trees of tropical Australia and China

    NASA Astrophysics Data System (ADS)

    Togashi, H. F.; Prentice, I. C. C.; Atkin, O. K.; Bloomfield, K. J.; Bradford, M.; Weerasinghe, L. K.; Harrison, S. P.; Evans, B. J.; Liddell, M. J.; Wang, H.; Cao, K. F.; Fan, Z.

    2015-12-01

    The representation of Plant Functional Types (PFTs) in current generation of Dynamic Global Vegetation Models (DGVMs) is excessively simplistically. Key ecophysiological properties, such as photosynthesis biochemistry, are most times merely averaged and trade-off with other plant traits is often neglected. Validation of a PFT framework based in photosynthetic process is crucial to improve reliability of DGVMs. We present 431 leaf-biochemical and wood level measurements in evergreen angiosperm trees of tropical forests in Australia and China that were divided in four spectrums of plant trait variation: metabolic, structural, hydraulic and height dimensions. Plant traits divided in each of these dimensions adopt survival strategies reflected more clearly by trade-off within each spectrum, and in some extent across spectrums. Co-ordination theory (that Rubisco- and electron-transport limited rates of photosynthesis are co-limiting) and least-coast theory (that intercellular to ambient CO2 concentration minimizes the combined costs per unit carbon assimilation, regulating maximum height and wood density) expectations matched PFT (which takes in account canopy position and light access, and life spam) variation. Our findings suggest that climate (air moisture, air temperature, light) has lower power representing these dimensions, in comparison to the PFT framework.

  12. Comparison of Evapotranspiration and Forest Cover Type in the Southeast United States: A Long-term Water Budget Approach

    NASA Astrophysics Data System (ADS)

    Younger, S. E.

    2015-12-01

    This study assessed the relationship between evapotranspiration (ET) and different types of forest for 74 gaged drainage basins in the Southeast United States with at least 29 years of data and greater than 40% forest cover. The objective was to determine if a difference in tree water use was detectible at the USGS gaged basin scale. It was hypothesized that ET rates are higher in Evergreen dominated watershed due to greater annual productivity. Discharge from United States Geological Survey (USGS) gages (D), landcover from the National Landcover Dataset (NLCD), and precipitation (P) from Daymet, Mauer, Observed Gridded, and PRISM. Annual ET was estimated using ET = P - D. To reduce geological influences the study basins were selected from an area of crystalline bedrock within the Piedmont and Southern Blue Ridge physiographic provinces. Correlations between ET and forest type show a significant difference between evergreen and deciduous forest cover. Evergreen forest dominated watersheds had a positive relationship with ET. Deciduous and Mixed forest dominated watersheds had a negative relationship with ET. These findings are similar to other studies looking at the effect of forest type on ET although other land uses in the basins have potentially indiscernible influences on discharge.

  13. Presence of understory shrubs constrains carbon gain in sunflecks by advance-regeneration seedlings: evidence from Quercus Rubra seedling grouwing in understory forest patches with or without evergreen shrubs present

    Treesearch

    E.T. Nilsen; T.T. Lei; S.W. Semones

    2009-01-01

    We investigated whether dynamic photosynthesis of understory Quercus rubra L. (Fagaceae) seedlings can acclimate to the altered pattern of sunflecks in forest patches with Rhododendron maximum L. (Ericaceae), an understory evergreen shrub. Maximum photosynthesis (A) and total CO2 accumulated during lightflecks was greatest for 400-s lightflecks, intermediate for 150-s...

  14. Effect of Severe Winter Cold on the Photosynthetic Potentials of Three Co-occurring Evergreen Woody Species in a Mediterranean Forest, Catalonia (Spain)

    NASA Astrophysics Data System (ADS)

    Sperlich, Dominik; Gracia, Carlos; Peñuelas, Josep; Sabaté, Santi

    2013-04-01

    Evergreen tree species in the Mediterranean region have to cope with a wide range of environmental stress conditions from summer drought to winter cold. The winter period can lead to photoinhibition due to a combination of high solar irradiances and chilling temperatures which can reduce the light saturation point. However, Mediterranean winter mildness can lead periodically to favourable environmental conditions above the threshold for positive carbon balance benefitting evergreen woody species in contrast to winter deciduous species. The advantage of being able to photosynthesis all year round with a significant fraction in the winter month is compensating for the lower photosynthetic potentials during spring and summer in comparison to deciduous species. In this work, we investigated the physiological behaviour of three evergreen tree species (Quercus ilex, Pinus halepensis, Arbutus undeo) co-occurring in a natural and mature Mediterranean forest after a period of mild winter conditions and their response to a sudden period of intense cold weather. Therefore, we examined in each period the photosynthetic potentials by estimating the maximum carboxylation rate (Vcmax) and the maximum electron transport rate (Jmax) through gas exchange measurements. The results indicate that all species exhibited extraordinary high photosynthetic potentials during the first period of measurement as a response to the mild conditions. However, the sudden cold period affected negatively the photosynthetic potentials of Quercus ilex and A. unedo with reduction ranging between 37 to 45 %, whereas they were observed to be only insignificantly reduced in Pinus halepensis. Our results can be explained by previous classifications into photoinhibition-avoiding (P. halpensis) and photoinhibition-tolerant (Q. ilex, A. undeo) species on the basis of their susceptibility to dynamic photoinhibition (Martinez Ferri 2000). Photoinhibition tolerant species are characterised with a more dynamic

  15. Variation in Plant Traits Explains Global Biogeographic Variation in the Abundance of Major Forest Functional Types

    NASA Astrophysics Data System (ADS)

    Wang, Y.

    2015-12-01

    Contrasting leaf types (needle vs. broadleaf) with different lifespans (annual vs. perennial) represent different adaptive strategies of plants under different environmental conditions. Previous studies explained adaptive advantages of different strategies using empirical models but cannot adequately explain the co-dominance of multiple plant functional types (PFTs) as observed in many parts of the world. Here we used a process-based model to explore whether observed inter- and intra-PFT variation in key plant traits can explain global biogeographic variation in co-dominance of major forest functional types. Using a parameter screening method, we identified the four most important plant traits for simulating annual net primary production (NPP) using the Australian Community Atmosphere-Biosphere-Land Exchange model (CABLE). Using ensemble CABLE simulations, we estimated the fraction of global land cover attributed to each PFT by comparing the simulated NPP for all three PFTs at each land point, globally. Our results were consistent with land area cover fractions of major forest types estimated from remote sensing data products; i.e., evergreen needle-leaf forests dominate in boreal regions, evergreen broadleaf forests dominate in tropical regions, and deciduous broadleaf forests are distributed widely across a broad range of environmental conditions. More importantly our approach successfully explained a paradox that has puzzled ecologists for over a century: why evergreen leaf types dominate in both boreal and tropical regions. We conclude that variation in and co-variation between key plant traits can explain significant fractions of global biogeographic variation of three major forest types, and should be taken into account when simulating global vegetation dynamics.

  16. Carbon dioxide exchange in a cool-temperate evergreen coniferous forest over complex topography in Japan during two years with contrasting climates.

    PubMed

    Saitoh, Taku M; Tamagawa, Ichiro; Muraoka, Hiroyuki; Lee, Na-Yeon M; Yashiro, Yuichiro; Koizumi, Hiroshi

    2010-07-01

    We investigated carbon dioxide (CO(2)) exchange and its environmental response during two years with contrasting climate (2006 and 2007) in a cool-temperate mixed evergreen coniferous forest dominated by Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtusa). The study, which was conducted in a mountainous region of central Japan, used the eddy-covariance technique. Our results (crosschecked using the common u (*) approach and van Gorsel's alternative approach) showed that annual gross primary production (GPP) and ecosystem respiration (RE) were at least 6% higher in the dry year than in the wet year, whereas net ecosystem exchange (NEE) was similar in both years. Without soil water stress, strong light stress or seasonality of plant area index during most of the study period, the forest had high metabolic activity. GPP and RE differed greatly between the two years, especially in spring (April-May) and summer (July-September), respectively. The spring GPP difference (>20%) was influenced by different winter air temperatures and snow melt timing, which controlled photosynthetic capacity in spring, and by different spring light intensities. The annual NEE differed depending on the evaluation method used, but the mean 2-year NEE estimated by the u (*) threshold approach [-3.39 +/- 0.11 (SD) MgC ha(-1) year(-1)] appears more reasonable in comparison with results from other forests.

  17. Variation in plant traits explains much of the global biogeographic patterns of distribution of major forest functional types

    NASA Astrophysics Data System (ADS)

    Lu, Xingjie; Wang, Ying-Ping; Reich, Peter; Wright, Ian; Dai, Yongjiu

    2015-04-01

    Contrasting foliage types (needle and broad leaf) and phenological habits (deciduous and evergreen) represent different adaptive strategies of trees, which can be quantified by the differences in a number of key plant traits. Previous studies have used vegetation models to explain adaptive advantage of different strategies as represented by the mean values of those key plant traits for each plant functional types, and are unable to explain the co-existence of multiple plant functional types in the absence of disturbance. However significant variations and co-variations among those key plant traits that have been observed within a plant functional type may have significant implication on the simulated competition among different plant functional types. Here we use the Australian Community Atmosphere-Biosphere-Land Exchange model (CABLE) to explore whether the observed key plant traits (leaf life span, leaf carbon allocation fraction, basal respiration rate of plant tissue, and leaf C:N ratio) can explain the observed co-existence of four forest types (evergreen or deciduous, needle leaf or broad leaf forests) globally. To incorporate the intra-specific variation of plant traits into the model, we run four groups of ensemble simulations, with each group including only one PFT prescribed in all forested land cells. Then we calculate the annual NPP at each one-degree forested land cell for each of 200 parameter sets that are randomly generated from the observed mean and variances of those key plant traits. Using NPP as a proxy for fitness, we calculate the probability of a forest PFT with higher NPP than all other three forest PFTs for each forested land cell by comparing each of 200 NPP estimates of a forest PFT with the NPP estimates of all other three forest PFTs. Assuming that probability is proportional to area abundance, we then compare the estimated abundance of all four forest types with the estimates from remote sensing. Overall our results captured the global

  18. Phylobetadiversity among forest types in the Brazilian Atlantic Forest complex.

    PubMed

    Duarte, Leandro Da Silva; Bergamin, Rodrigo Scarton; Marcilio-Silva, Vinícius; Seger, Guilherme Dubal Dos Santos; Marques, Márcia Cristina Mendes

    2014-01-01

    Phylobetadiversity is defined as the phylogenetic resemblance between communities or biomes. Analyzing phylobetadiversity patterns among different vegetation physiognomies within a single biome is crucial to understand the historical affinities between them. Based on the widely accepted idea that different forest physiognomies within the Southern Brazilian Atlantic Forest constitute different facies of a single biome, we hypothesize that more recent phylogenetic nodes should drive phylobetadiversity gradients between the different forest types within the Atlantic Forest, as the phylogenetic divergence among those forest types is biogeographically recent. We compiled information from 206 checklists describing the occurrence of shrub/tree species across three different forest physiognomies within the Southern Brazilian Atlantic Forest (Dense, Mixed and Seasonal forests). We analyzed intra-site phylogenetic structure (phylogenetic diversity, net relatedness index and nearest taxon index) and phylobetadiversity between plots located at different forest types, using five different methods differing in sensitivity to either basal or terminal nodes (phylogenetic fuzzy weighting, COMDIST, COMDISTNT, UniFrac and Rao's H). Mixed forests showed higher phylogenetic diversity and overdispersion than the other forest types. Furthermore, all forest types differed from each other in relation phylobetadiversity patterns, particularly when phylobetadiversity methods more sensitive to terminal nodes were employed. Mixed forests tended to show higher phylogenetic differentiation to Dense and Seasonal forests than these latter from each other. The higher phylogenetic diversity and phylobetadiversity levels found in Mixed forests when compared to the others likely result from the biogeographical origin of several taxa occurring in these forests. On one hand, Mixed forests shelter several temperate taxa, like the conifers Araucaria and Podocarpus. On the other hand, tropical groups, like

  19. Phylobetadiversity among Forest Types in the Brazilian Atlantic Forest Complex

    PubMed Central

    Duarte, Leandro Da Silva; Bergamin, Rodrigo Scarton; Marcilio-Silva, Vinícius; Seger, Guilherme Dubal Dos Santos; Marques, Márcia Cristina Mendes

    2014-01-01

    Phylobetadiversity is defined as the phylogenetic resemblance between communities or biomes. Analyzing phylobetadiversity patterns among different vegetation physiognomies within a single biome is crucial to understand the historical affinities between them. Based on the widely accepted idea that different forest physiognomies within the Southern Brazilian Atlantic Forest constitute different facies of a single biome, we hypothesize that more recent phylogenetic nodes should drive phylobetadiversity gradients between the different forest types within the Atlantic Forest, as the phylogenetic divergence among those forest types is biogeographically recent. We compiled information from 206 checklists describing the occurrence of shrub/tree species across three different forest physiognomies within the Southern Brazilian Atlantic Forest (Dense, Mixed and Seasonal forests). We analyzed intra-site phylogenetic structure (phylogenetic diversity, net relatedness index and nearest taxon index) and phylobetadiversity between plots located at different forest types, using five different methods differing in sensitivity to either basal or terminal nodes (phylogenetic fuzzy weighting, COMDIST, COMDISTNT, UniFrac and Rao’s H). Mixed forests showed higher phylogenetic diversity and overdispersion than the other forest types. Furthermore, all forest types differed from each other in relation phylobetadiversity patterns, particularly when phylobetadiversity methods more sensitive to terminal nodes were employed. Mixed forests tended to show higher phylogenetic differentiation to Dense and Seasonal forests than these latter from each other. The higher phylogenetic diversity and phylobetadiversity levels found in Mixed forests when compared to the others likely result from the biogeographical origin of several taxa occurring in these forests. On one hand, Mixed forests shelter several temperate taxa, like the conifers Araucaria and Podocarpus. On the other hand, tropical groups

  20. Photosynthesis of overwintering evergreen plants.

    PubMed

    Oquist, Gunnar; Huner, Norman P A

    2003-01-01

    In this review we focus on photosynthetic behavior of overwintering evergreens with an emphasis on both the acclimative responses of photosynthesis to cold and the winter behavior of photosynthesis in conifers. Photosynthetic acclimation is discussed in terms of the requirement for a balance between the energy absorbed through largely temperature-insensitive photochemical processes and the energy used for temperature-sensitive biochemical processes and growth. Cold acclimation transforms the xanthophyll-mediated nonphotochemical antenna quenching of absorbed light from a short-term dynamic response to a long-term sustained quenching for the whole winter period. This acclimative response helps protect the evergreen foliage from photooxidative damage during the winter when photosynthesis is restricted or prevented by low temperatures. Although the molecular mechanisms behind the sustained winter excitation quenching are largely unknown, it does involve major alterations in the organization and composition of the photosystem II antenna. In addition, photosystem I may play an important role in overwintering evergreens not only by quenching absorbed light photochemically via its support of cyclic electron transport at low temperatures, but also by nonphotochemical quenching of absorbed light irrespective of temperature. The possible role of photosystem II reaction centers in nonphotochemical quenching of absorbed energy in overwintering evergreens is also discussed. Processes like chlororespiration and cyclic electron transport may also be important for maintaining the functional integrity of the photosynthetic apparatus of overwintering evergreens both during periods of thawing in winter and during recovery from winter stress in spring. We suggest that the photosynthetic acclimation responses of overwintering evergreens represent specific evolutionary adaptations for plant species that invest in the long-term maintenance of leaf structure in cold climatic zones as

  1. Development of defoliating insects and their preferences for host plants under varying temperatures in a subtropical evergreen forest in eastern China

    NASA Astrophysics Data System (ADS)

    Jing, Jun; Xia, Lingdan; Li, Kai

    2016-09-01

    The aim of this work was to understand the development of defoliating insects and their preferences for host plants under varying temperatures in a subtropical evergreen broad-leaved forest in China. We measured the main developmental parameters of three typical defoliating insects (i.e., Ourapteryx ebuleata szechuana, Biston marginata, and Euproctis angulata) and their preferences for five host plants at temperatures from 16°C to 31°C at 3°C intervals in the Tiantong National Forest Research station in eastern China. The results showed the following. 1) An appropriate rise in temperature increases the survival rate with an increase in the number of offspring. The developmental durations for these three insects were shortened, and pupal weight increased with an increase in temperature. 2) A shift in the preference for host plants for these three insects was observedat elevated temperatures. They all preferred to feed on Schima superba and Castanopsis sclerophylla at elevated temperatures, showing an opposite response to the other three plants. The daily leaf consumption of the three insects was positively correlated with their feeding preference, with more leaves being consumed from the plants they preferred. 3) For O. ebuleata szechuana larvae, daily leaf consumption initially increased and then decreased with increasing temperatures. In contrast, Biston marginata and Euproctis angulata larvae consumed more leaves at elevated temperatures. The feeding preferences of O. ebuleata szechuana and Biston marginata were more sensitive to changing temperatures than that of Euproctis angulata laevae. We concluded that increased numbers of offspring and generations, pupal weights, and a shift in preference to two plants for these three defoliating insects might lead to severe damage to these two plants which would enhance the fragmentation and decrease the stability of the forest communities under changing temperatures. Meanwhile, the variations in the responses of

  2. The effects of ice storm on seed rain and seed limitation in an evergreen broad-leaved forest in east China

    NASA Astrophysics Data System (ADS)

    Du, Yanjun; Mi, Xiangcheng; Liu, Xiaojuan; Ma, Keping

    2012-02-01

    Extreme climatic events almost universally play a major role in influencing the composition and structure of plant and animal communities, and thus could influence seed production, seed dispersal and seedling recruitment. We explored the effects of ice storm damage on seed rain and seed limitation in a 24-ha permanent forest plot in an evergreen broad-leaved forest in east China. We compared seed production before and after the storm in 2008. We evaluated the following hypotheses: 1) seed production after the ice storm was less than that before the storm; 2) seed limitation after the storm was more severe than before the storm. The results showed that seeds from one species, Eurya muricata, dominated the seed rain after the storm, accounting for more than half of the total seeds. Post-ice storm seed production of species other than E. muricata was only one fifth of that before the storm. Seed production in the second year after the ice storm recovered to pre-storm levels. The results indicate large inter-specific variation in response to the ice storm. Disturbance caused by the ice storm greatly increased seed diversity. The Jaccard similarity of species before and after the ice storm was 58%. There was no significant difference in seed limitation or dispersal limitation before and after the storm, but there was a significant difference in source limitation. Neither seed limitation nor dispersal limitation was correlated with dispersal modes. Only source limitation for rodent dispersed species increased after the ice storm.

  3. [Species-area relationship at different succession stages of monsoon evergreen broad-leaved forest in south subtropical area of Yunnan Province].

    PubMed

    Liu, Wan-De; Su, Jian-Rong; Li, Shuai-Feng; Zhang, Zhi-Jun; Lang, Xue-Dong

    2011-02-01

    Based on the investigation data of monsoon evergreen broad-leaved forest at its different succession stages (primary, CP; 15 years of succession, CF; and 30 years of succession, CT) in Pu' er of Yunnan Province, this paper studied the species-area relationship of this forest at each succession stage. It was found that in the communities at each succession stage, the number of total species, trees, shrubs, and lianas had a significant correlation with sampling area, with the area explained over 94% of the total variation. The Z value of the total species (0.334) and trees (0.394) was the lowest at CT, whereas that of shrubs (0.437) and lianas (0.326) was the lowest at CF. No significant differences were observed in the intercepts of the species-area curve of total species, trees, shrubs, and lianas among different succession stages, but the coefficient of determination (R2) of the species-area curve of total species and lianas was the highest at CP. The richness of trees and shrubs at CF explained 99.9% of the variance of Z value, but the richness of total species, trees, shrubs, and lianas at CP and CT had no significant correlations with the Z value.

  4. Forest type mapping with satellite data

    NASA Technical Reports Server (NTRS)

    Dodge, A. G., Jr.; Bryant, E. S.

    1976-01-01

    Computer classification of data from Landsat, an earth-orbiting satellite, has resulted in measurements and maps of forest types for two New Hampshire counties. The acreages of hardwood and softwood types and total forested areas compare favorably with Forest Service figures for the same areas. These techniques have advantages for field application, particularly in states having forest taxation laws based on general productivity.

  5. Forest type mapping with satellite data

    NASA Technical Reports Server (NTRS)

    Dodge, A. G., Jr.; Bryant, E. S.

    1976-01-01

    Computer classification of data from Landsat, an earth-orbiting satellite, has resulted in measurements and maps of forest types for two New Hampshire counties. The acreages of hardwood and softwood types and total forested areas compare favorably with Forest Service figures for the same areas. These techniques have advantages for field application, particularly in states having forest taxation laws based on general productivity.

  6. Mapping forest functional type in a forest-shrubland ecotone using SPOT imagery and predictive habitat distribution modelling

    USGS Publications Warehouse

    Assal, Timothy J.; Anderson, Patrick J.; Sibold, Jason

    2015-01-01

    The availability of land cover data at local scales is an important component in forest management and monitoring efforts. Regional land cover data seldom provide detailed information needed to support local management needs. Here we present a transferable framework to model forest cover by major plant functional type using aerial photos, multi-date Système Pour l’Observation de la Terre (SPOT) imagery, and topographic variables. We developed probability of occurrence models for deciduous broad-leaved forest and needle-leaved evergreen forest using logistic regression in the southern portion of the Wyoming Basin Ecoregion. The model outputs were combined into a synthesis map depicting deciduous and coniferous forest cover type. We evaluated the models and synthesis map using a field-validated, independent data source. Results showed strong relationships between forest cover and model variables, and the synthesis map was accurate with an overall correct classification rate of 0.87 and Cohen’s kappa value of 0.81. The results suggest our method adequately captures the functional type, size, and distribution pattern of forest cover in a spatially heterogeneous landscape.

  7. Estimation of gross primary production and light use efficiency by the tower-based sun-induced fluorescence measurement in the Japanese evergreen coniferous forest

    NASA Astrophysics Data System (ADS)

    Tsujimoto, K.; Kato, T.; Hirano, T.; Saitoh, T. M.; Nagai, S.; Akitsu, T.; Nasahara, K. N.

    2015-12-01

    Chlorophyll fluorescence (ChlF) is emitted from chlorophyll a and b to release the excess sun-light energy. Recently, ChlF has been utilized to represent the ecosystem photosynthetic activity, i.e. gross primary production (GPP), by the satellite remote-sensing studies (e.g. Frankenberg et al., 2011). Despite its high expectation, small number of ecosystem-level ChlF observation at the ground reduces its availability. The aim of this study is to clarify the relationships between ChlF, and photosynthesis and light use efficiency (LUE) by the ground based measurement in the forest. The observations were carried out in the evergreen coniferous forest in Takayama, Japan, from March 2008 to February 2009. Downward and upward spectral radiances were measured with hemispherical spectroradiometer (MS-700, Eko Instruments, Japan) mounted at 30m-high above the ground surface. We calculated Sun-Induced fluorescence (FS) around the O2-A band (760 nm) from the spectral data with the Fraunhofer Line Depth method. The GPP was calculated from the carbon fluxes measured with eddy covariance at the top of the tower. FS showed the strong correlation to GPP linearly in the diurnal course (sunny day (8 August, 2008): r2 = 0.81, cloudy day (28 July, 2008): r2 = 0.87). In addition, GPP was fitted against FS by rectangular hyperbolic curve. (r2 = 0.87 (daily)). We also investigated the relationship between FS and LUE in daily averages. The FS-LUE relationship could be regressed by logarithm curve for each month (r2 = 0.46 ˜0.95). The seasonal changes in the regression coefficients for FS-GPP and FS-LUE curves were thought to be induced by the seasonal variation in the temperature-dependency of photosynthesis and the phenology. We conclude that FS can be utilized to estimate GPP and LUE in evergreen forest, and that relationship between FS and GPP is influenced by environmental factors such as PAR and air temperature.Chlorophyll fluorescence (ChlF) is emitted from chlorophyll a and b to

  8. On the difference in the net ecosystem exchange of CO2 between deciduous and evergreen forests in the southeastern United States.

    PubMed

    Novick, Kimberly A; Oishi, A Christopher; Ward, Eric J; Siqueira, Mario B S; Juang, Jehn-Yih; Stoy, Paul C

    2015-02-01

    The southeastern United States is experiencing a rapid regional increase in the ratio of pine to deciduous forest ecosystems at the same time it is experiencing changes in climate. This study is focused on exploring how these shifts will affect the carbon sink capacity of southeastern US forests, which we show here are among the strongest carbon sinks in the continental United States. Using eight-year-long eddy covariance records collected above a hardwood deciduous forest (HW) and a pine plantation (PP) co-located in North Carolina, USA, we show that the net ecosystem exchange of CO2 (NEE) was more variable in PP, contributing to variability in the difference in NEE between the two sites (ΔNEE) at a range of timescales, including the interannual timescale. Because the variability in evapotranspiration (ET) was nearly identical across the two sites over a range of timescales, the factors that determined the variability in ΔNEE were dominated by those that tend to decouple NEE from ET. One such factor was water use efficiency, which changed dramatically in response to drought and also tended to increase monotonically in nondrought years (P < 0.001 in PP). Factors that vary over seasonal timescales were strong determinants of the NEE in the HW site; however, seasonality was less important in the PP site, where significant amounts of carbon were assimilated outside of the active season, representing an important advantage of evergreen trees in warm, temperate climates. Additional variability in the fluxes at long-time scales may be attributable to slowly evolving factors, including canopy structure and increases in dormant season air temperature. Taken together, study results suggest that the carbon sink in the southeastern United States may become more variable in the future, owing to a predicted increase in drought frequency and an increase in the fractional cover of southern pines. © 2014 John Wiley & Sons Ltd.

  9. Seed rain, soil seed bank, seed loss and regeneration of Castanopsis fargesii (Fagaceae) in a subtropical evergreen broad-leaved forest

    USGS Publications Warehouse

    Du, X.; Guo, Q.; Gao, X.; Ma, K.

    2007-01-01

    Understanding the seed rain and seed loss dynamics in the natural condition has important significance for revealing the natural regeneration mechanisms. We conducted a 3-year field observation on seed rain, seed loss and natural regeneration of Castanopsis fargesii Franch., a dominant tree species in evergreen broad-leaved forests in Dujiangyan, southwestern China. The results showed that: (1) there were marked differences in (mature) seed production between mast (733,700 seeds in 2001) and regular (51,200 and 195,600 seeds in 2002 and 2003, respectively) years for C. fargesii. (2) Most seeds were dispersed in leaf litter, humus and 0-2 cm depth soil in seed bank. (3) Frequency distributions of both DBH and height indicated that C. fargesii had a relatively stable population. (4) Seed rain, seed ground density, seed loss, and leaf fall were highly dynamic and certain quantity of seeds were preserved on the ground for a prolonged time due to predator satiation in both the mast and regular years so that the continuous presence of seed bank and seedling recruitments in situ became possible. Both longer time observations and manipulative experiments should be carried out to better understand the roles of seed dispersal and regeneration process in the ecosystem performance. ?? 2006 Elsevier B.V. All rights reserved.

  10. [Spatial patterns of and specific correlations between dominant tree species in a karst evergreen and deciduous broadleaved mixed forest in Mulun Karst National Nature Reserve].

    PubMed

    Han, Wen-heng; Xiang, Wu-sheng; Ye, Duo; Lü, Shi-hong; Ding, Tao; Li, Xian-kun

    2010-11-01

    In order to understand the biological characteristics and specific correlations of dominant tree species in a karst characteristic evergreen and deciduous broad-leaved mixed forest in Mulun National Nature Reserve of Guangxi, a point pattern analysis was made on the spatial distribution patterns and inter- and intraspecific correlations of four dominant species in a one-hectare plot. Among the four species, Boniodendron minius dominated in tree sublayer I, while Ligustrum japonicum, Sinosideroxylon wightianum, and Rapanea kwangsiensis dominated in tree sublayers II and III. All the four species had a clumped distribution at scale <10 m, a transition from clumped to random distribution at scale 10-25 m, and a random or regular distribution at scale >25 m. The critical scale from clumped to random distribution varied with species. No significant correlations were observed between the B. minius in sublayer I and the dominant species in sublayer II. The correlations of B. minius with the dominant species in sublayers II and III showed greater fluctuation, with significant positive correlation for L. japonicum at scale <50 m, no significant correlation for S. wightianum, and no significant correlation for R. kwangsiensis at scale <20 m but significant negative correlation at scale 20-50 m.

  11. Establishment of the evergreen broad-leaved tree species Castanopsis cuspidata in an abandoned secondary forest in western Japan.

    PubMed

    Hirayama, Kimiko; Kawamura, Shota; Nishimura, Tatsuya; Takahara, Hikaru

    2010-09-01

    Recently, populations of Castanopsis cuspidata have often expanded into secondary forests in western Japan. To determine the establishment processes of this species, we analyzed its spatial distribution in a secondary forest dominated by Quercus variabilis and Quercus serrata that is located adjacent to a stand dominated by C. cuspidata. Saplings, defined as >or=30 cm stem length (SL) and <5 cm diameter at breast height (DBH), were abundant and their size distribution was inversely J-shaped, indicating continuous recruitment. Although seedlings (SL < 30 cm) and small saplings (30 or=40 m from the nearest adults, suggesting that there is animal-aided dispersal of acorns. The distribution of larger-sized individuals (>or=100 cm SL) of C. cuspidata was unrelated to distance from the nearest flowering C. cuspidata or dominant Quercus species (>or=5 cm DBH), but was associated with dead Pinus densiflora trees, which were abundant at the site. Thus, the establishment of C. cuspidata in this forest is controlled mainly by two factors, viz. patterns of acorn dispersal by animals, and forest disturbance regime (i.e., deaths of pine trees).

  12. Regeneration of different plant functional types in a Masson pine forest following pine wilt disease.

    PubMed

    Hu, Guang; Xu, Xuehong; Wang, Yuling; Lu, Gao; Feeley, Kenneth J; Yu, Mingjian

    2012-01-01

    Pine wilt disease is a severe threat to the native pine forests in East Asia. Understanding the natural regeneration of the forests disturbed by pine wilt disease is thus critical for the conservation of biodiversity in this realm. We studied the dynamics of composition and structure within different plant functional types (PFTs) in Masson pine forests affected by pine wilt disease (PWD). Based on plant traits, all species were assigned to four PFTs: evergreen woody species (PFT1), deciduous woody species (PFT2), herbs (PFT3), and ferns (PFT4). We analyzed the changes in these PFTs during the initial disturbance period and during post-disturbance regeneration. The species richness, abundance and basal area, as well as life-stage structure of the PFTs changed differently after pine wilt disease. The direction of plant community regeneration depended on the differential response of the PFTs. PFT1, which has a higher tolerance to disturbances, became dominant during the post-disturbance regeneration, and a young evergreen-broad-leaved forest developed quickly after PWD. Results also indicated that the impacts of PWD were dampened by the feedbacks between PFTs and the microclimate, in which PFT4 played an important ecological role. In conclusion, we propose management at the functional type level instead of at the population level as a promising approach in ecological restoration and biodiversity conservation.

  13. Regeneration of Different Plant Functional Types in a Masson Pine Forest Following Pine Wilt Disease

    PubMed Central

    Hu, Guang; Xu, Xuehong; Wang, Yuling; Lu, Gao; Feeley, Kenneth J.; Yu, Mingjian

    2012-01-01

    Pine wilt disease is a severe threat to the native pine forests in East Asia. Understanding the natural regeneration of the forests disturbed by pine wilt disease is thus critical for the conservation of biodiversity in this realm. We studied the dynamics of composition and structure within different plant functional types (PFTs) in Masson pine forests affected by pine wilt disease (PWD). Based on plant traits, all species were assigned to four PFTs: evergreen woody species (PFT1), deciduous woody species (PFT2), herbs (PFT3), and ferns (PFT4). We analyzed the changes in these PFTs during the initial disturbance period and during post-disturbance regeneration. The species richness, abundance and basal area, as well as life-stage structure of the PFTs changed differently after pine wilt disease. The direction of plant community regeneration depended on the differential response of the PFTs. PFT1, which has a higher tolerance to disturbances, became dominant during the post-disturbance regeneration, and a young evergreen-broad-leaved forest developed quickly after PWD. Results also indicated that the impacts of PWD were dampened by the feedbacks between PFTs and the microclimate, in which PFT4 played an important ecological role. In conclusion, we propose management at the functional type level instead of at the population level as a promising approach in ecological restoration and biodiversity conservation. PMID:22563499

  14. Changes in soil carbon and nutrients following 6 years of litter removal and addition in a tropical semi-evergreen rain forest

    NASA Astrophysics Data System (ADS)

    Tanner, Edmund Vincent John; Sheldrake, Merlin W. A.; Turner, Benjamin L.

    2016-11-01

    Increasing atmospheric CO2 and temperature may increase forest productivity, including litterfall, but the consequences for soil organic matter remain poorly understood. To address this, we measured soil carbon and nutrient concentrations at nine depths to 2 m after 6 years of continuous litter removal and litter addition in a semi-evergreen rain forest in Panama. Soils in litter addition plots, compared to litter removal plots, had higher pH and contained greater concentrations of KCl-extractable nitrate (both to 30 cm); Mehlich-III extractable phosphorus and total carbon (both to 20 cm); total nitrogen (to 15 cm); Mehlich-III calcium (to 10 cm); and Mehlich-III magnesium and lower bulk density (both to 5 cm). In contrast, litter manipulation did not affect ammonium, manganese, potassium or zinc, and soils deeper than 30 cm did not differ for any nutrient. Comparison with previous analyses in the experiment indicates that the effect of litter manipulation on nutrient concentrations and the depth to which the effects are significant are increasing with time. To allow for changes in bulk density in calculation of changes in carbon stocks, we standardized total carbon and nitrogen on the basis of a constant mineral mass. For 200 kg m-2 of mineral soil (approximately the upper 20 cm of the profile) about 0.5 kg C m-2 was "missing" from the litter removal plots, with a similar amount accumulated in the litter addition plots. There was an additional 0.4 kg C m-2 extra in the litter standing crop of the litter addition plots compared to the control. This increase in carbon in surface soil and the litter standing crop can be interpreted as a potential partial mitigation of the effects of increasing CO2 concentrations in the atmosphere.

  15. Forest Restoration in China: Advances, Obstacles, and Perspectives

    Treesearch

    Hai Ren; Hongfang Lu; Jun Wang; Nan Liu; Qinfeng Guo

    2012-01-01

    Because of the prolonged history of disturbance caused by intense human activities, restoration in China has been a major task facing many ecologists and land managers. There are six major forest types in China: cold temperate coniferous forest, temperate coniferous and broad-leaved mixed forest, warm temperate deciduous broad-leaved forest, subtropical evergreen broad...

  16. [Allelopathic potential of Phyllostachys edulis on two dominant tree species of evergreen broad-leaved forest in its invasive process].

    PubMed

    Bai, Shang-Bin; Zhou, Guo-Mo; Wang, Yi-Xiang; Liang, Qian-Qian; Chen, Juan; Cheng, Yan-Yan; Shen, Rui

    2013-10-01

    In order to explore the influence of Phyllostachys edulis invasion on the surrounding forest environment,the effects of aqueous extracts from P. edulis on two dominant species (Castanopsis sclerophylla and Cyclobalanopsis glaunca)in southern China were assessed by germination bioassays. The results showed that seed germination effects depended on the concentration of aqueous extracts and the extract sources. The highest extract concentration showed significant inhibitory effects on seed germination percentage, which was 82. 3% -102. 2% of control for C. sclerophylla and 80% -90. 9% of control for C. glauca, while in the treatment with lowest extract concentration the values were 101.7% - 107.6% of control for C. sclerophylla and 94.9% - 109. 1% of control for C. glauca, respectively. The extracts had inhibitory effects on the germination speed of both species (P < 0.05) , except that no effects on C. sclerophylla were observed in the low concentration treatment. Extracts at the highest concentration reduced the root activity of C. sclerophylla by 41. 1% -62. 4% (P <0.05). There were obvious different effects among the treatments with different extract sources. Seed germination percentage was the lowest in root extract treatments. There was no obvious difference for shoot height of C. sclerophylla in different treatments(P >0.05) , while there was significant difference for C. glauca, its shoot height was higher in the leaf, root, and litter extracts treatments than in the soil extracts treatments. P. edulis possesses allelopathic potential that could possibly facilitate its invasion and monoculture formation, and does harm to the surrounding forest environment.

  17. Tree size and light availability increase photochemical instead of non-photochemical capacities of Nothofagus nitida trees growing in an evergreen temperate rain forest.

    PubMed

    Coopman, Rafael E; Briceño, Verónica F; Corcuera, Luis J; Reyes-Díaz, Marjorie; Alvarez, Daniela; Sáez, Katherine; García-Plazaola, José I; Alberdi, Miren; Bravo, León A

    2011-10-01

    Nothofagus nitida (Phil.) Krasser (Nothofagaceae) regenerates under the canopy in microsites protected from high light. Nonetheless, it is common to find older saplings in clear areas and adults as emergent trees of the Chilean evergreen forest. We hypothesized that this shade to sun transition in N. nitida is supported by an increase in photochemical and non-photochemical energy dissipation capacities of both photosystems in parallel with the increase in plant size and light availability. To dissect the relative contribution of light environment and plant developmental stage to these physiological responses, the photosynthetic performance of both photosystems was studied from the morpho-anatomical to the biochemical level in current-year leaves of N. nitida plants of different heights (ranging from 0.1 to 7 m) growing under contrasting light environments (integrated quantum flux (IQF) 5-40 mol m(-2). Tree height (TH) and light environment (IQF) independently increased the saturated electron transport rates of both photosystems, as well as leaf and palisade thickness, but non-photochemical energy flux, photoinhibition susceptibility, state transition capacity, and the contents of D1 and PsbS proteins were not affected by IQF and TH. Spongy mesophyll thickness and palisade cell diameter decreased with IQF and TH. A(max), light compensation and saturation points, Rubisco and nitrogen content (area basis) only increased with light environment (IQF), whereas dark respiration (R(d)) decreased slightly and relative chlorophyll content was higher in taller trees. Overall, the independent effects of more illuminated environment and tree height mainly increased the photochemical instead of the non-photochemical energy flux. Regardless of the photochemical increase with TH, carbon assimilation only significantly improved with higher IQF. Therefore it seems that mainly acclimation to the light environment supports the phenotypic transition of N. nitida from shade to

  18. Increasing carbon discrimination rates and depth of water uptake favor the growth of Mediterranean evergreen trees in the ecotone with temperate deciduous forests.

    PubMed

    Barbeta, Adrià; Peñuelas, Josep

    2017-05-22

    Tree populations at the low-altitudinal or -latitudinal limits of species' distributional ranges are predicted to retreat toward higher altitudes and latitudes to track the ongoing changes in climate. Studies have focused on the climatic sensitivity of the retreating species, whereas little is known about the potential replacements. Competition between tree species in forest ecotones will likely be strongly influenced by the ecophysiological responses to heat and drought. We used tree-ring widths and δ(13) C and δ(18) O chronologies to compare the growth rates and long-term ecophysiological responses to climate in the temperate-Mediterranean ecotone formed by the deciduous Fagus sylvatica and the evergreen Quercus ilex at the low altitudinal and southern latitudinal limit of F. sylvatica (NE Iberian Peninsula). F. sylvatica growth rates were similar to those of other southern populations and were surprisingly not higher than those of Q. ilex, which were an order of magnitude higher than those in nearby drier sites. Higher Q. ilex growth rates were associated with high temperatures, which have increased carbon discrimination rates in the last 25 years. In contrast, stomatal regulation in F. sylvatica was proportional to the increase in atmospheric CO2 . Tree-ring δ(18) O for both species were mostly correlated with δ(18) O in the source water. In contrast to many previous studies, relative humidity was not negatively correlated with tree-ring δ(18) O but had a positive effect on Q. ilex tree-ring δ(18) O. Furthermore, tree-ring δ(18) O decreased in Q. ilex over time. The sensitivity of Q. ilex to climate likely reflects the uptake of deep water that allowed it to benefit from the effect of CO2 fertilization, in contrast to the water-limited F. sylvatica. Consequently, Q. ilex is a strong competitor at sites currently dominated by F. sylvatica and could be favored by increasingly warmer conditions. © 2017 John Wiley & Sons Ltd.

  19. Antimicrobial Potential, Identification and Phylogenetic Affiliation of Wild Mushrooms from Two Sub-Tropical Semi-Evergreen Indian Forest Ecosystems

    PubMed Central

    Lallawmsanga; Passari, Ajit Kumar; Mishra, Vineet Kumar; Leo, Vincent Vineeth; Valliammai Meyyappan, Geetha; Gupta, Vijai Kumar; Uthandi, Sivakumar; Upadhyay, Ramesh Chandra

    2016-01-01

    The diversity of wild mushrooms was investigated from two protected forest areas in India and 231 mushroom specimens were morphologically identified. Among them, 76 isolates were screened for their antimicrobial potential against seven bacterial and fungal pathogens. Out of 76 isolates, 45 isolates which displayed significant antimicrobial activities were identified using ITS rRNA gene amplification and subsequently phylogenetically characterized using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. Sequencing of the ITS rRNA region classified the isolates into 16 genera belonging to 11 families. In total, 11 RAPD and 10 ISSR primers were selected to evaluate genetic diversity based on their banding profile produced. In total 337 RAPD and 312 ISSR bands were detected, among which percentage of polymorphism ranges from 34.2% to 78.8% and 38.6% to 92.4% by using RAPD and ISSR primers respectively. Unweighted Pair-Group Method with Arithmetic Mean (UPGMA) trees of selected two methods were structured similarly, grouping the 46 isolates into two clusters which clearly showed a significant genetic distance among the different strains of wild mushroom, with an similarity coefficient ranges from 0.58 to 1.00 and 0.59 to 1.00 with RAPD and ISSR analysis respectively. This reporthas highlighted both DTR and MNP forests provide a habitat for diverse macrofungal species, therefore having the potential to be used for the discovery of antimicrobials. The report has also demonstrated that both RAPD and ISSR could efficiently differentiate wild mushrooms and could thus be considered as efficient markers for surveying genetic diversity. Additionally, selected six wild edible mushroom strains (Schizophyllum commune BPSM01, Panusgiganteus BPSM27, Pleurotussp. BPSM34, Lentinussp. BPSM37, Pleurotusdjamor BPSM41 and Lentinula sp. BPSM45) were analysed for their nutritional (proteins, carbohydrates, fat and ash content), antioxidant potential

  20. Antimicrobial Potential, Identification and Phylogenetic Affiliation of Wild Mushrooms from Two Sub-Tropical Semi-Evergreen Indian Forest Ecosystems.

    PubMed

    Lallawmsanga; Passari, Ajit Kumar; Mishra, Vineet Kumar; Leo, Vincent Vineeth; Singh, Bhim Pratap; Valliammai Meyyappan, Geetha; Gupta, Vijai Kumar; Uthandi, Sivakumar; Upadhyay, Ramesh Chandra

    2016-01-01

    The diversity of wild mushrooms was investigated from two protected forest areas in India and 231 mushroom specimens were morphologically identified. Among them, 76 isolates were screened for their antimicrobial potential against seven bacterial and fungal pathogens. Out of 76 isolates, 45 isolates which displayed significant antimicrobial activities were identified using ITS rRNA gene amplification and subsequently phylogenetically characterized using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. Sequencing of the ITS rRNA region classified the isolates into 16 genera belonging to 11 families. In total, 11 RAPD and 10 ISSR primers were selected to evaluate genetic diversity based on their banding profile produced. In total 337 RAPD and 312 ISSR bands were detected, among which percentage of polymorphism ranges from 34.2% to 78.8% and 38.6% to 92.4% by using RAPD and ISSR primers respectively. Unweighted Pair-Group Method with Arithmetic Mean (UPGMA) trees of selected two methods were structured similarly, grouping the 46 isolates into two clusters which clearly showed a significant genetic distance among the different strains of wild mushroom, with an similarity coefficient ranges from 0.58 to 1.00 and 0.59 to 1.00 with RAPD and ISSR analysis respectively. This reporthas highlighted both DTR and MNP forests provide a habitat for diverse macrofungal species, therefore having the potential to be used for the discovery of antimicrobials. The report has also demonstrated that both RAPD and ISSR could efficiently differentiate wild mushrooms and could thus be considered as efficient markers for surveying genetic diversity. Additionally, selected six wild edible mushroom strains (Schizophyllum commune BPSM01, Panusgiganteus BPSM27, Pleurotussp. BPSM34, Lentinussp. BPSM37, Pleurotusdjamor BPSM41 and Lentinula sp. BPSM45) were analysed for their nutritional (proteins, carbohydrates, fat and ash content), antioxidant potential

  1. Forest habitat types of central Idaho

    Treesearch

    Robert Steele; Robert D. Pfister; Russell A. Ryker; Jay A. Kittams

    1981-01-01

    A land-classification system based upon potential natural vegetation is presented for the forests of central Idaho. It is based on reconnaissance sampling of about 800 stands. A hierarchical taxonomic classification of forest sites was developed using the habitat type concept. A total of eight climax series, 64 habitat types, and 55 additional phases of habitat types...

  2. Pollination ecology and reproductive biology of Canarium strictum Roxb. from evergreen forests of Central Western Ghats, India.

    PubMed

    Kumar, C N Prasanna; Somashekar, R K; Nagaraja, B C; Shivaprasad, D

    2015-09-01

    Pollination and reproductive biology of a dioecious tree Canarium strictum Roxb. (Burseraceae) was extensively studied within the Agumbe forest range of Western Ghats, Karnataka to identify primary pollen vectors and to enumerate interrelationship with the pollinators. The study also investigated phenology, floral biology, pollen production, pollen viability, stigma receptivity and nectar production. Trees produced functionally unisexual flowers with white petals, organized densely on inflorescences. Staminate flowers produced high percentage of viable pollen and relatively abundant nectar (15.75 μl) as a reward to the pollinators, while pistillate flowers produced only nectar (12 μl). Successful fruit set with wind pollination was facilitated by synchronization of flowering male and female trees, long term receptivity of stigma in female flowers and extended lifespan of flowers. The highest mean percent of fruit set with hand cross-pollination (μ = 91.06) suggests the influence of local male tree density, as well as, frequency and abundance of pollinator community on fruit set by open pollination.

  3. Climatic controls of vegetation vigor in four contrasting forest types of India--evaluation from National Oceanic and Atmospheric Administration's Advanced Very High Resolution Radiometer datasets (1990-2000).

    PubMed

    Prasad, V Krishna; Anuradha, E; Badarinath, K V S

    2005-09-01

    Ten-day advanced very high resolution radiometer images from 1990 to 2000 were used to examine spatial patterns in the normalized difference vegetation index (NDVI) and their relationships with climatic variables for four contrasting forest types in India. The NDVI signal has been extracted from homogeneous vegetation patches and has been found to be distinct for deciduous and evergreen forest types, although the mixed-deciduous signal was close to the deciduous ones. To examine the decadal response of the satellite-measured vegetation phenology to climate variability, seven different NDVI metrics were calculated using the 11-year NDVI data. Results suggested strong spatial variability in forest NDVI metrics. Among the forest types studied, wet evergreen forests of north-east India had highest mean NDVI (0.692) followed by evergreen forests of the Western Ghats (0.529), mixed deciduous forests (0.519) and finally dry deciduous forests (0.421). The sum of NDVI (SNDVI) and the time-integrated NDVI followed a similar pattern, although the values for mixed deciduous forests were closer to those for evergreen forests of the Western Ghats. Dry deciduous forests had higher values of inter-annual range (RNDVI) and low mean NDVI, also coinciding with a high SD and thus a high coefficient of variation (CV) in NDVI (CVNDVI). SNDVI has been found to be high for wet evergreen forests of north-east India, followed by evergreen forests of the Western Ghats, mixed deciduous forests and dry deciduous forests. Further, the maximum NDVI values of wet evergreen forests of north-east India (0.624) coincided with relatively high annual total precipitation (2,238.9 mm). The time lags had a strong influence in the correlation coefficients between annual total rainfall and NDVI. The correlation coefficients were found to be comparatively high (R2=0.635) for dry deciduous forests than for evergreen forests and mixed deciduous forests, when the precipitation data with a lag of 30 days was

  4. Identifying Southern Forest Types on Aerial Photographs

    Treesearch

    Gene Avery

    1960-01-01

    This booklet has been prepared to assist photo interpreters in recognizing broad forest types on aerial photographs of the South, and to illustrate primary differences between panchromatic and infrared photography from the standpoint of timber type-mapping.

  5. Species-specific and seasonal differences in chlorophyll fluorescence and photosynthetic light response among three evergreen species in a Madrean sky island mixed conifer forest

    NASA Astrophysics Data System (ADS)

    Potts, D. L.; Minor, R. L.; Braun, Z.; Barron-Gafford, G. A.

    2012-12-01

    -use efficiency (AQE) was similar among P. strobiformis and P. ponderosa and least in P. menziesii (repeated-measures ANOVA; species, F2,8 = 13.83, P = 0.002). Across all three species, monsoon onset increased AQE (repeated-measures ANOVA; time, F1,8= 10.04, P = 0.01). Likewise, P. strobiformis and P. ponderosa shared a similar, greater light compensation point than P. menziesii (repeated-measures ANOVA; species, F2,8 = 5.89, P = 0.02). However, across species, monsoon onset did not influence light compensation points. These results support the hypothesis that the monsoon has species-specific effects on evergreen physiological performance and are broadly consistent with predictions of stress tolerance based on species' latitudinal and elevational range distributions. Moreover, with year-to-year rainfall variability predicted to increase under future climate scenarios, species-specific functional traits related to stress tolerance and photosynthesis may promote ecosystem functional resilience in Madrean sky island mixed conifer forests.

  6. Forest type mapping of the Interior West

    Treesearch

    Bonnie Ruefenacht; Gretchen G. Moisen; Jock A. Blackard

    2004-01-01

    This paper develops techniques for the mapping of forest types in Arizona, New Mexico, and Wyoming. The methods involve regression-tree modeling using a variety of remote sensing and GIS layers along with Forest Inventory Analysis (FIA) point data. Regression-tree modeling is a fast and efficient technique of estimating variables for large data sets with high accuracy...

  7. Water cycle observations in forest watersheds of Cambodia

    NASA Astrophysics Data System (ADS)

    Shimizu, A.; Tamai, K.; Kabeya, N.; Shimizu, T.; Iida, S. I.

    2015-12-01

    The Lower Mekong River flows through Cambodia, where forests cover ~60% of the country and are believed to have a marked effect on the water cycle. These tropical seasonal forests in the Cambodian flat lands are very precious in the Indochinese Peninsula as few forests of this type remain. However, few hydrological observations have been conducted in these areas. In Cambodia, deciduous and evergreen forests make up 42% and 33% of the total forest area, respectively. We established experimental watersheds both in deciduous and evergreen forests containing meteorological observation towers in Cambodia and collected various observational data since 2003 (O'Krieng, deciduous forest watershed including a 30-m-high observation tower, 2,245 km2; Stung Chinit, evergreen forest watershed including a 60-m-high observation tower, 3,700 km2 including three small watersheds). The basic data from these sites included various kinds of information related to the composition of vegetation, soil characteristics, etc. Hydrologic data was collected and linked to the above data; the main hydrologic research results follow. The water budget for each watershed was determined using an observational rainfall and runoff dataset. The evapotranspiration rate in an evergreen forest was obtained using various observational methods including the Bowen energy-balance ratio and the bandpass eddy covariance method. The annual evapotranspiration of evergreen forests, estimated using the Bowen energy-balance ratio method and water balance, was about 1100-1200 mm, corresponding to 70-80% of annual rainfall. While considering the importance of the presence of evergreen forest, we conducted sap flow measurements to analyze the transpiration process that maintains water uptake through root systems that reach to depths exceeding 8 m. Characteristics of the evaporation from the forest floor that form an important element of the evaporation system were estimated in both evergreen and deciduous forests.

  8. An Old-Growth Definition for Southwestern Subtropical Upland Forests

    Treesearch

    David D. Diamond

    1998-01-01

    Mainly evergreen, broad-leaved forests in the Southwestern United States are restricted to the Lower Rio Grande Valley of Texas. The soils and long growing season make this region valuable cropland, and, thus, almost all of the area once occupied by this forest type has been converted to row crops. Remaining old-growth forests are usually dominated by some combination...

  9. Fire ecology of western Montana forest habitat types

    Treesearch

    William C. Fischer; Anne F. Bradley

    1987-01-01

    Provides information on fire as an ecological factor for forest habitat types in western Montana. Identifies Fire Groups of habitat types based on fire's role in forest succession. Describes forest fuels and suggests considerations for fire management.

  10. 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.

  11. Experiment at Evergreen.

    ERIC Educational Resources Information Center

    Jones, Richard M.

    The philosophy and structure of programs of coordinated study at Evergreen State College from 1970 to 1980 are discussed, and comparisons are made to the experiment at the University of California, Berkeley, promoted by Joseph Tussman. Both programs are based on ideas suggested by Alexander Meiklejohn and his Experimental College at the University…

  12. Climate response of the soil nitrogen cycle in three forest types of a headwater Mediterranean catchment

    NASA Astrophysics Data System (ADS)

    Lupon, Anna; Gerber, Stefan; Sabater, Francesc; Bernal, Susana

    2015-05-01

    Future changes in climate may affect soil nitrogen (N) transformations, and consequently, plant nutrition and N losses from terrestrial to stream ecosystems. We investigated the response of soil N cycling to changes in soil moisture, soil temperature, and precipitation across three Mediterranean forest types (evergreen oak, beech, and riparian) by fusing a simple process-based model (which included climate modifiers for key soil N processes) with measurements of soil organic N content, mineralization, nitrification, and concentration of ammonium and nitrate. The model describes sources (atmospheric deposition and net N mineralization) and sinks (plant uptake and hydrological losses) of inorganic N from and to the 0-10 cm soil pool as well as net nitrification. For the three forest types, the model successfully recreated the magnitude and temporal pattern of soil N processes and N concentrations (Nash-Sutcliffe coefficient = 0.49-0.96). Changes in soil water availability drove net N mineralization and net nitrification at the oak and beech forests, while temperature and precipitation were the strongest climatic factors for riparian soil N processes. In most cases, net N mineralization and net nitrification showed a different sensitivity to climatic drivers (temperature, soil moisture, and precipitation). Our model suggests that future climate change may have a minimal effect on the soil N cycle of these forests (<10% change in mean annual rates) because positive warming and negative drying effects on the soil N cycle may counterbalance each other.

  13. Fallout volume and litter type affect (137)Cs concentration difference in litter between forest and stream environments.

    PubMed

    Sakai, Masaru; Gomi, Takashi; Negishi, Junjiro N

    2016-11-01

    It is important to understand the changes in the (137)Cs concentration in litter through leaching when considering that (137)Cs is transferred from basal food resources to animals in forested streams. We found that the difference of (137)Cs activity concentration in litter between forest and stream was associated with both litter type and (137)Cs fallout volume around Fukushima, Japan. The (137)Cs activity concentrations in the litter of evergreen conifers tended to be greater than those in the litter of broad-leaved deciduous trees because of the absence of deciduous leaves during the fallout period in March 2011. Moreover, (137)Cs activity concentrations in forest litter were greater with respect to the (137)Cs fallout volume. The (137)Cs activity concentrations in stream litter were much lower than those in forest litter when those in forest litter were higher. The (137)Cs leaching patterns indicated that the differences in (137)Cs activity concentration between forest and stream litter could change with changes in both fallout volume and litter type. Because litter is an important basal food resource in the food webs of both forests and streams, the (137)Cs concentration gradient reflects to possible (137)Cs transfer from lower to higher trophic animals. Our findings will improve our understanding of the spatial heterogeneity and variability of (137)Cs concentrations in animals resident to the contaminated landscape. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Effects of plot size on forest-type algorithm accuracy

    Treesearch

    James A. Westfall

    2009-01-01

    The Forest Inventory and Analysis (FIA) program utilizes an algorithm to consistently determine the forest type for forested conditions on sample plots. Forest type is determined from tree size and species information. Thus, the accuracy of results is often dependent on the number of trees present, which is highly correlated with plot area. This research examines the...

  15. The advantages of being evergreen.

    PubMed

    Aerts, R

    1995-10-01

    Recent research shows that the dominance of evergreen species in nutrient-poor environments can be explained by their low nutrient loss rates. From this work It appears that the plant traits that are associated with low nutrient loss rates lead to low maximum-dry-matter production and to low rates of litter decomposition. This suggests a positive feedback between the evergreen habit and low nutrient availability. The growth characteristics of evergreens lead to a low responsiveness to environmental changes. As a result, global warming may lead to changes in the distribution of evergreens.

  16. Do evergreen and deciduous trees have different effects on net N mineralization in soil?

    PubMed

    Mueller, Kevin E; Hobbie, Sarah E; Oleksyn, Jacek; Reich, Peter B; Eissenstat, David M

    2012-06-01

    Evergreen and deciduous plants are widely expected to have different impacts on soil nitrogen (N) availability because of differences in leaf litter chemistry and ensuing effects on net N mineralization (N(min)). We evaluated this hypothesis by compiling published data on net N(min) rates beneath co-occurring stands of evergreen and deciduous trees. The compiled data included 35 sets of co-occurring stands in temperate and boreal forests. Evergreen and deciduous stands did not have consistently divergent effects on net N(min) rates; net N(min) beneath deciduous trees was higher when comparing natural stands (19 contrasts), but equivalent to evergreens in plantations (16 contrasts). We also compared net N(min) rates beneath pairs of co-occurring genera. Most pairs of genera did not differ consistently, i.e., tree species from one genus had higher net N(min) at some sites and lower net N(min) at other sites. Moreover, several common deciduous genera (Acer, Betula, Populus) and deciduous Quercus spp. did not typically have higher net N(min) rates than common evergreen genera (Pinus, Picea). There are several reasons why tree effects on net N(min) are poorly predicted by leaf habit and phylogeny. For example, the amount of N mineralized from decomposing leaves might be less than the amount of N mineralized from organic matter pools that are less affected by leaf litter traits, such as dead roots and soil organic matter. Also, effects of plant traits and plant groups on net N(min) probably depend on site-specific factors such as stand age and soil type.

  17. Conterminous U.S. and Alaska Forest Type Mapping Using Forest Inventory and Analysis Data

    Treesearch

    B. Ruefenacht; M.V. Finco; M.D. Nelson; R. Czaplewski; E.H. Helmer; J. A. Blackard; G.R. Holden; A.J. Lister; D. Salajanu; D. Weyermann; K. Winterberger

    2008-01-01

    Classification-trees were used to model forest type groups and forest types for the conterminous United States and Alaska. The predictor data were a geospatial data set with a spatial resolution of 250 m developed by the U.S. Department of Agriculture Forest Service (USFS). The response data were plot data from the USFS Forest Inventory and Analysis program. Overall...

  18. Determining stocking, forest type and stand-size class from forest inventory data

    Treesearch

    Mark H. Hansen; Jerold T. Hahn

    1992-01-01

    This paper describes the procedures used by North Central Forest Experiment Station's Forest Inventory and Analysis Work Unit (NCFIA) in determining stocking, forest type, and stand-size class. The stocking procedure assigns a portion of the stocking to individual trees measured on NCFIA 10-point field plots. Stand size and forest type are determined as functions...

  19. Arum- and Paris-type arbuscular mycorrhizas in a mixed pine forest on sand dune soil in Niigata Prefecture, central Honshu, Japan.

    PubMed

    Matekwor Ahulu, Evelyn; Nakata, Makoto; Nonaka, Masanori

    2005-03-01

    Arbuscular mycorrhizas (AM) are the most widespread mycorrhiza in nature and form two morphologies, Arum- and Paris-type. The determining factors defining the two different morphologies are not well understood. In this study, the distribution of Arum- and Paris-type AM was determined in a mixed pine forest. A total of 35 plant species belonging to 20 families and 32 genera were identified and examined for AM colonization and morphological types. AM morphological types in 14 families were confirmed as follows: Arum-type in Rosaceae, Oleaceae, Lauraceae, Vitaceae and Compositae, Paris-type in Aquifoliaceae, Ulmaceae, Araliaceae, Theaceae, Magnoliaceae, Rubiaceae and Dioscoraceae, and both and/or intermediate types in Caprifoliaceae and Gramineae. Plant families whose AM morphological status was previously unknown were clarified as follows: Polygonaceae and Commelinaceae showed Arum-type morphology; Celastraceae, Menispermaceae and Elaeagnaceae had typical Paris-type morphology. The proportion of Arum-type to Paris-type species decreased in the following order: annuals > perennials > deciduous species > evergreen species, and pioneer group > early successional group > late successional group. Evergreen plants had a higher tendency to form Paris-type AM than annuals, perennials and deciduous plants. The results indicate that environmental changes, such as shade during plant succession, control the distribution of plant growth forms in mixed pine forest and may also play a part in the distribution of Arum- and Paris-type morphology. The identity of the plant seems to strongly influence AM morphology, though control by the fungal genome cannot be ruled out.

  20. Fire ecology of the forest habitat types of central Idaho

    Treesearch

    M. F. Crane; William C. Fischer

    1986-01-01

    Discusses fire as an ecological factor for forest habitat types occurring in central Idaho. Identifies "Fire Groups" of habitat types based on fire's role in forest succession. Considerations for fire management are suggested.

  1. A Computer Program for Displaying Forest Survey Type Information

    Treesearch

    B. Bruce Bare; Robert N. Stone

    1968-01-01

    Presents a computerized procedure for displaying forest type information from inventory plots. Although the development of general forest type maps in emphasized, the program can be used to display any locational data having rectangular coordinates

  2. LOCALIZING NATIONAL FRAGMENTATION STATISTICS WITH FOREST TYPE MAPS

    EPA Science Inventory

    Fragmmentation of forest types is an indicator of biodiversity in the Montreal Process, but the available national data permit assessment of only overall forestland fragmentation, not forest type fragmentation. Here we illustrate how to localize national statistics from the 2003...

  3. LOCALIZING NATIONAL FRAGMENTATION STATISTICS WITH FOREST TYPE MAPS

    EPA Science Inventory

    Fragmmentation of forest types is an indicator of biodiversity in the Montreal Process, but the available national data permit assessment of only overall forestland fragmentation, not forest type fragmentation. Here we illustrate how to localize national statistics from the 2003...

  4. The role of forest type in the variability of DOC in atmospheric deposition at forest plots in Italy.

    PubMed

    Arisci, S; Rogora, M; Marchetto, A; Dichiaro, F

    2012-06-01

    Dissolved organic carbon (DOC) was studied in atmospheric deposition samples collected on a weekly basis in 2005-2009 at 10 forest plots in Italy. The plots covered a wide range of geographical attributes and were representative of the main forest types in Italy. Both spatial and temporal variations in DOC concentrations and fluxes are discussed, with the aim of identifying the main factors affecting DOC variability. DOC concentration increased from bulk to throughfall and stemflow water samples at all sites, as an effect of leaching from leaves and branches, going from 0.7-1.7 mg C L(-1) in bulk samples to 1.8-15.8 mg C L(-1) in throughfall and 4.2-10.7 mg C L(-1) in stemflow, with striking differences among the various plots. Low concentrations were found in runoff (0.5-2.0 mg C L(-1)), showing that the export of DOC via running waters was limited. The seasonality of DOC in throughfall samples was evident, with the highest concentration in summer when biological activity is at a maximum, and minima in winter due to limited DOC production and leaching. Statistical analysis revealed that DOC had a close relationship with organic and total nitrogen, and with nutrient ions, and a negative correlation with precipitation amount. Forest type proved to be a major factor affecting DOC variability: concentration and, to a lesser extent, fluxes were lower in stands dominated by deciduous species. The character of evergreens, and the size and shape of their leaves and needles, which regulate the interception mechanism of dry deposition, are mainly responsible for this.

  5. On the difference in the net ecosystem exchange of CO2 between deciduous and evergreen forests in the southeastern United States

    Treesearch

    Kimberly A. Novick; A. Christopher Oishi; Eric J. Ward; Mario B.S. Siqueira; Jehn-Yih Juang; Paul C. Stoy

    2015-01-01

    The southeastern United States is experiencing a rapid regional increase in the ratio of pine to deciduous forest ecosystems at the same time it is experiencing changes in climate. This study is focused on exploring how these shifts will affect the carbon sink capacity of southeastern US forests, which we show here are among the strongest carbon sinks in the...

  6. Studying Evergreen Trees in December.

    ERIC Educational Resources Information Center

    Platt, Dorothy K.

    1991-01-01

    This lesson plan uses evergreen trees on sale in cities and villages during the Christmas season to teach identification techniques. Background information, activities, and recommended references guides deal with historical, symbolic and current uses of evergreen trees, physical characteristics, selection, care, and suggestions for post-Christmas…

  7. Analysis of the 1996 Wisconsin forest statistics by habitat type.

    Treesearch

    John Kotar; Joseph A. Kovach; Gary Brand

    1999-01-01

    The fifth inventory of Wisconsin's forests is presented from the perspective of habitat type as a classification tool. Habitat type classifies forests based on the species composition of the understory plant community. Various forest attributes are summarized by habitat type and management implications are discussed.

  8. Woodland Birds in Three Different Forest Types in Eastern Texas

    Treesearch

    Clifford E. Shackelford; Richard N. Conner

    1996-01-01

    Birds were censusedalong three routes through relatively mature forest in eastern Texas using the fixed circular plot technique. The routes sampled three forest types (based on tree species composition): (1)longleaf pine (Pinus palustris) Savannah, (2) mixed pine-hardwood forest, and (3) bottomland hardwood forest. Each route consisted of 20 plots censused twice...

  9. Assimilating leaf area index of three typical types of subtropical forest in China from MODIS time series data based on the integrated ensemble Kalman filter and PROSAIL model

    NASA Astrophysics Data System (ADS)

    Li, Xuejian; Mao, Fangjie; Du, Huaqiang; Zhou, Guomo; Xu, Xiaojun; Han, Ning; Sun, Shaobo; Gao, Guolong; Chen, Liang

    2017-04-01

    Subtropical forest ecosystems play essential roles in the global carbon cycle and in carbon sequestration functions, which challenge the traditional understanding of the main functional areas of carbon sequestration in the temperate forests of Europe and America. The leaf area index (LAI) is an important biological parameter in the spatiotemporal simulation of the carbon cycle, and it has considerable significance in carbon cycle research. Dynamic retrieval based on remote sensing data is an important method with which to obtain large-scale high-accuracy assessments of LAI. This study developed an algorithm for assimilating LAI dynamics based on an integrated ensemble Kalman filter using MODIS LAI data, MODIS reflectance data, and canopy reflectance data modeled by PROSAIL, for three typical types of subtropical forest (Moso bamboo forest, Lei bamboo forest, and evergreen and deciduous broadleaf forest) in China during 2014-2015. There were some errors of assimilation in winter, because of the bad data quality of the MODIS product. Overall, the assimilated LAI well matched the observed LAI, with R2 of 0.82, 0.93, and 0.87, RMSE of 0.73, 0.49, and 0.42, and aBIAS of 0.50, 0.23, and 0.03 for Moso bamboo forest, Lei bamboo forest, and evergreen and deciduous broadleaf forest, respectively. The algorithm greatly decreased the uncertainty of the MODIS LAI in the growing season and it improved the accuracy of the MODIS LAI. The advantage of the algorithm is its use of biophysical parameters (e.g., measured LAI) in the LAI assimilation, which makes it possible to assimilate long-term MODIS LAI time series data, and to provide high-accuracy LAI data for the study of carbon cycle characteristics in subtropical forest ecosystems.

  10. Ecological Importance of Small-Diameter Trees to the Structure, Diversity and Biomass of a Tropical Evergreen Forest at Rabi, Gabon.

    PubMed

    Memiaghe, Hervé R; Lutz, James A; Korte, Lisa; Alonso, Alfonso; Kenfack, David

    2016-01-01

    Tropical forests have long been recognized for their biodiversity and ecosystem services. Despite their importance, tropical forests, and particularly those of central Africa, remain understudied. Until recently, most forest inventories in Central Africa have focused on trees ≥10 cm in diameter, even though several studies have shown that small-diameter tree population may be important to demographic rates and nutrient cycling. To determine the ecological importance of small-diameter trees in central African forests, we used data from a 25-ha permanent plot that we established in the rainforest of Gabon to study the diversity and dynamics of these forests. Within the plot, we censused 175,830 trees ≥1 cm dbh from 54 families, 192 genera, and 345 species. Average tree density was 7,026 trees/ha, basal area 31.64 m2/ha, and above-ground biomass 369.40 Mg/ha. Fabaceae, Ebenaceae and Euphorbiaceae were the most important families by basal area, density and above-ground biomass. Small-diameter trees (1 cm ≥ dbh <10 cm) comprised 93.7% of the total tree population, 16.5% of basal area, and 4.8% of the above-ground biomass. They also had diversity 18% higher at family level, 34% higher at genus level, and 42% higher at species level than trees ≥10 cm dbh. Although the relative contribution of small-diameter trees to biomass was comparable to other forests globally, their contribution to forest density, and diversity was disproportionately higher. The high levels of diversity within small-diameter classes may give these forests high levels of structural resilience to anthropogenic/natural disturbance and a changing climate.

  11. Ecological Importance of Small-Diameter Trees to the Structure, Diversity and Biomass of a Tropical Evergreen Forest at Rabi, Gabon

    PubMed Central

    Memiaghe, Hervé R.; Lutz, James A.; Korte, Lisa; Alonso, Alfonso; Kenfack, David

    2016-01-01

    Tropical forests have long been recognized for their biodiversity and ecosystem services. Despite their importance, tropical forests, and particularly those of central Africa, remain understudied. Until recently, most forest inventories in Central Africa have focused on trees ≥10 cm in diameter, even though several studies have shown that small-diameter tree population may be important to demographic rates and nutrient cycling. To determine the ecological importance of small-diameter trees in central African forests, we used data from a 25-ha permanent plot that we established in the rainforest of Gabon to study the diversity and dynamics of these forests. Within the plot, we censused 175,830 trees ≥1 cm dbh from 54 families, 192 genera, and 345 species. Average tree density was 7,026 trees/ha, basal area 31.64 m2/ha, and above-ground biomass 369.40 Mg/ha. Fabaceae, Ebenaceae and Euphorbiaceae were the most important families by basal area, density and above-ground biomass. Small-diameter trees (1 cm ≥ dbh <10 cm) comprised 93.7% of the total tree population, 16.5% of basal area, and 4.8% of the above-ground biomass. They also had diversity 18% higher at family level, 34% higher at genus level, and 42% higher at species level than trees ≥10 cm dbh. Although the relative contribution of small-diameter trees to biomass was comparable to other forests globally, their contribution to forest density, and diversity was disproportionately higher. The high levels of diversity within small-diameter classes may give these forests high levels of structural resilience to anthropogenic/natural disturbance and a changing climate. PMID:27186658

  12. Localizing National Fragmentation Statistics with Forest Type Maps

    Treesearch

    Kurt H. Riitters; John W. Coulston; James D. Wickham

    2003-01-01

    Fragmentation of forest types is an indicator of biodiversity in the Montreal Process, but the available national data permit assessment of only overall forestland fragmentation, not forest type fragmentation. Here we illustrate how to localize national statistics from the 2003 National Report on Sustainable Forests by combining state vegetation maps with national...

  13. How Do Evergreens Stay Ever-Green? Hands on Science.

    ERIC Educational Resources Information Center

    Kepler, Lynne

    1993-01-01

    Provides instructional techniques, using samples from evergreen trees, to explain to school children the concept of adaptation. The techniques help children develop skills in observation, classification, communication, inferring, and predicting. A teacher's reproducible is included. (GLR)

  14. How Do Evergreens Stay Ever-Green? Hands on Science.

    ERIC Educational Resources Information Center

    Kepler, Lynne

    1993-01-01

    Provides instructional techniques, using samples from evergreen trees, to explain to school children the concept of adaptation. The techniques help children develop skills in observation, classification, communication, inferring, and predicting. A teacher's reproducible is included. (GLR)

  15. Seasonal ozone uptake by a warm-temperate mixed deciduous and evergreen broadleaf forest in western Japan estimated by the Penman-Monteith approach combined with a photosynthesis-dependent stomatal model.

    PubMed

    Kitao, Mitsutoshi; Komatsu, Masabumi; Hoshika, Yasutomo; Yazaki, Kenichi; Yoshimura, Kenichi; Fujii, Saori; Miyama, Takafumi; Kominami, Yuji

    2014-01-01

    Canopy-level stomatal conductance over a warm-temperate mixed deciduous and evergreen broadleaf forest in Japan was estimated by the Penman-Monteith approach, as compensated by a semi-empirical photosynthesis-dependent stomatal model, where photosynthesis, relative humidity, and CO2 concentration were assumed to regulate stomatal conductance. This approach, using eddy covariance data and routine meteorological observations at a flux tower site, permits the continuous estimation of canopy-level O3 uptake, even when the Penman-Monteith approach is unavailable (i.e. in case of direct evaporation from soil or wet leaves). Distortion was observed between the AOT40 exposure index and O3 uptake through stomata, as AOT40 peaked in April, but with O3 uptake occurring in July. Thus, leaf pre-maturation in the predominant deciduous broadleaf tree species (Quercus serrata) might suppress O3 uptake in springtime, even when the highest O3 concentrations were observed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. 29 CFR 780.1013 - Natural evergreens.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Natural evergreens. 780.1013 Section 780.1013 Labor... Provisions Under Section 13(d) Requirements for Exemption § 780.1013 Natural evergreens. Only “natural” evergreens may comprise the principal part of the wreath. The word “natural” qualifies all of the evergreens...

  17. 29 CFR 780.1013 - Natural evergreens.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Natural evergreens. 780.1013 Section 780.1013 Labor... Provisions Under Section 13(d) Requirements for Exemption § 780.1013 Natural evergreens. Only “natural” evergreens may comprise the principal part of the wreath. The word “natural” qualifies all of the evergreens...

  18. Regenerative potential and functional composition of soil seed banks in remnant evergreen broad-leaved forests under urbanization in South China

    Treesearch

    J. Wang; L. Huang; H. Ren; Z. Sun; Q. Guo

    2015-01-01

    Soil seed banks can act as an important source in forest regeneration, and the information on the seed bank composition is vital for determining the resilience of plant communities under severe environments such as urban settings. In this study, we examined the seed bank density and functional composition, and their relationships with aboveground vegetation in three...

  19. Regeneration Patterns in Canopy Gaps of Mixed-oak Forests of the Southern Appalachians: Influences of Topographic Position and Evergreen Understory

    Treesearch

    Barton D. Clinton; Lindsay R. Boring; Wayne T. Swank

    1994-01-01

    Canopy gaps in southern Appalachian mixed-oak forests were assessed for the effects of topographic, gap and stand variables on density of wood seedlings. Seedling density was significantly correlated with percent slope and positively with gap age (l-5 yr). Density varied substantially among topographic positions and increased with gap size. Species richness...

  20. Bird communities following high-severity fire: Response to single and repeat fires in a mixed-evergreen forest, Oregon, USA

    Treesearch

    Joseph B. Fontaine; Daniel C. Donato; W. Douglas Robinson; Beverly E. Law; J. Boone Kauffman

    2009-01-01

    Fire is a widespread natural disturbance agent in most conifer-dominated forests. In light of climate change and the effects of fire exclusion, single and repeated high-severity (stand-replacement) fires have become prominent land management issues. We studied bird communities using point counting in the Klamath-Siskiyou ecoregion of Oregon, USA at various points in...

  1. Developing and Applications of a Gap-filling Model for Eddy covariance CO2 Flux: Evaluating the Net Ecosystem Exchange of a Subtropical Evergreen Forest after a Server Environmental Disturbance

    NASA Astrophysics Data System (ADS)

    Li, M.; CHEN, Y.

    2013-12-01

    Successful eddy covariance (EC) applications often challenged by several difficulties, including non-ideal micrometeorological conditions, instrument failures, measurement limitations, and lacking consistent footprint area. Consequently, the resultant gaps in the time series of EC measurements limit the use of these dataset and cause the uncertainty in a range of 1 to 2 ton C/ha/yr for evaluating net ecosystem exchange (NEE) after different CO2 gap-filling procedures (Saigusa et al., 2013). It is crucial to develop a suitable gap-filling model for EC CO2 flux observations to provide reliable long-term surface fluxes for numerous applications. In this study, a gap-filling model was developed for EC CO2 flux by linking the gap-filled water vapor fluxes estimated by Chen et al. (2012) and the optimal nearest QC/QA passed CO2 fluxes for interpolating CO2 flux gaps. Considering the atmosphere characteristics and controlling mechanisms of CO2 fluxes, measured hydrometerological and flux data at the Lien-Hua-Chih (LHC) experimental watershed were separated into clear sky and cloudy/nighttime conditions. The successful applications of our gap-filling approaches were examined with various sizes of artificial CO2 gaps. Without any significant environmental disturbance in 2012, the annual NEE of this subtropical evergreen forest was estimated around 6.7 ton C/ha/yr as the amount of terrestrial CO2 sequestration. The effect of sever Typhoon Soulik (11-13, July, 2013) invasion on several ecosystem variables, such as changes of intrinsic water use efficiency, leaf area index, and canopy storage capacity, will be investigated to propose indicators for estimating NEE variations in association with environmental disturbances at this forest ecosystem.

  2. Relationships between net primary productivity and stand age for several forest types and their influence on China's carbon balance.

    PubMed

    Wang, Shaoqiang; Zhou, Lei; Chen, Jingming; Ju, Weimin; Feng, Xianfeng; Wu, Weixing

    2011-06-01

    Affected by natural and anthropogenic disturbances such as forest fires, insect-induced mortality and harvesting, forest stand age plays an important role in determining the distribution of carbon pools and fluxes in a variety of forest ecosystems. An improved understanding of the relationship between net primary productivity (NPP) and stand age (i.e., age-related increase and decline in forest productivity) is essential for the simulation and prediction of the global carbon cycle at annual, decadal, centurial, or even longer temporal scales. In this paper, we developed functions describing the relationship between national mean NPP and stand age using stand age information derived from forest inventory data and NPP simulated by the BEPS (Boreal Ecosystem Productivity Simulator) model in 2001. Due to differences in ecobiophysical characteristics of different forest types, NPP-age equations were developed for five typical forest ecosystems in China (deciduous needleleaf forest (DNF), evergreen needleleaf forest in tropic and subtropical zones (ENF-S), deciduous broadleaf forest (DBF), evergreen broadleaf forest (EBF), and mixed broadleaf forest (MBF)). For DNF, ENF-S, EBF, and MBF, changes in NPP with age were well fitted with a common non-linear function, with R(2) values equal to 0.90, 0.75, 0.66, and 0.67, respectively. In contrast, a second order polynomial was best suitable for simulating the change of NPP for DBF, with an R(2) value of 0.79. The timing and magnitude of the maximum NPP varied with forest types. DNF, EBF, and MBF reached the peak NPP at the age of 54, 40, and 32 years, respectively, while the NPP of ENF-S maximizes at the age of 13 years. The highest NPP of DBF appeared at 122 years. NPP was generally lower in older stands with the exception of DBF, and this particular finding runs counter to the paradigm of age-related decline in forest growth. Evaluation based on measurements of NPP and stand age at the plot-level demonstrates the reliability

  3. Fragmentation of eastern United States forest types

    Treesearch

    Kurt H. Riitters; John W. Coulston

    2013-01-01

    Fragmentation is a continuing threat to the sustainability of forests in the Eastern United States, where land use changes supporting a growing human population are the primary driver of forest fragmentation (Stein and others 2009). While once mostly forested, approximately 40 percent of the original forest area has been converted to other land uses, and most of the...

  4. Habitat types of the Tenderfoot Creek Experimental Forest

    Treesearch

    David M. Ondov

    1975-01-01

    In May 1974, a review draft of the Forest Habitat Types of Montana (Pfister et al. 1974) was released for use by Forest Service personnel and others requiring a method of ecosystem classification as a means to stratify forest environments in Montana. With the use of this review draft in mind, an objective was outlined to develop a vegetation map of the Tenderfoot Creek...

  5. Coarse root spatial distribution determined using a ground-penetrating radar technique in a subtropical evergreen broad-leaved forest, China.

    PubMed

    Yan, Hui; Dong, Xinliang; Feng, Gang; Zhang, Shouren; Mucciardi, Anthony

    2013-11-01

    Coarse roots play a critical role in forest ecosystems and both abiotic and biotic factors affect their spatial distribution. To some extent, coarse root density may reflect the quantity of root biomass and biotic competition in forests. However, using traditional methods (e.g., excavation) to study coarse roots is challenging, because those methods are time-consuming and laborious. Furthermore, these destructive methods cannot be repeated in the same forests. Therefore, the discovery of non-destructive methods for root studies will be very significant. In this study, we used a ground-penetrating radar technique to detect the coarse root density of three habitats (ridge, slope and valley) and the dominant tree species (Castanopsis eyrei and Schima superba) in a subtropical forest. We found that (i) the mean of coarse root density for these three habitats was 88.04 roots m(-2), with roots being mainly distributed at depths of 0-40 cm. Coarse root densities were lower in deeper soils and in areas far from the trunk. (ii) Coarse root densities differed significantly among the three habitats studied here with slope habitat having the lowest coarse root density. Compared with S. superba, C. eyrei had more roots distributed in deeper soils. Furthermore, coarse roots with a diameter >3 cm occurred more frequently in the valleys, compared with root densities in ridge and slope habitats, and most coarse roots occurred at soil depths of 20-40 cm. (iii) The coarse root density correlated negatively with tree species richness at soil depths of 40-60 cm. The abundances of the dominant species, such as C. eyrei, Cyclobalanopsis glauca, Pinus massoniana, had significant impacts on coarse root density. (iv) The soil depth of 0-40 cm was the "basic distribution layer" for coarse roots since the majority of coarse roots were found in this soil layer with an average root density of 84.18 roots m(-2), which had no significant linear relationships with topography, tree species richness

  6. Reliability of the Forest Service type rain gage

    Treesearch

    G. L. Hayes

    1942-01-01

    The Forest Service type rain-gage was originated by W. B. Osborne of the Portland, Oreg., office of the U. S. Forest Service to meet a need for reliable rainfall measurements at low cost. Many hundreds of them, over 700 on the national forests of northern Idaho and western Montana alone, are now being used during the summer months as aids to forest-fire control...

  7. Forest habitat types of eastern Idaho-western Wyoming

    Treesearch

    Robert Steele; Stephen V. Cooper; David M. Ondov; David W. Roberts; Robert D. Pfister

    1983-01-01

    A land-classification system based upon potential natural vegetation is presented for the forests of central Idaho. It is based on reconnaissance sampling of about 980 stands. A hierarchical taxonomic classification of forest sites was developed using the habitat type concept. A total of six climax series, 58 habitat types, and 24 additional phases of habitat types are...

  8. Soil organic matter quantity and quality shape microbial community compositions of subtropical broadleaved forests.

    PubMed

    Ding, Junjun; Zhang, Yuguang; Wang, Mengmeng; Sun, Xin; Cong, Jing; Deng, Ye; Lu, Hui; Yuan, Tong; Van Nostrand, Joy D; Li, Diqiang; Zhou, Jizhong; Yang, Yunfeng

    2015-10-01

    As two major forest types in the subtropics, broadleaved evergreen and broadleaved deciduous forests have long interested ecologists. However, little is known about their belowground ecosystems despite their ecological importance in driving biogeochemical cycling. Here, we used Illumina MiSeq sequencing targeting 16S rRNA gene and a microarray named GeoChip targeting functional genes to analyse microbial communities in broadleaved evergreen and deciduous forest soils of Shennongjia Mountain of Central China, a region known as 'The Oriental Botanic Garden' for its extraordinarily rich biodiversity. We observed higher plant diversity and relatively richer nutrients in the broadleaved evergreen forest than the deciduous forest. In odds to our expectation that plant communities shaped soil microbial communities, we found that soil organic matter quantity and quality, but not plant community parameters, were the best predictors of microbial communities. Actinobacteria, a copiotrophic phylum, was more abundant in the broadleaved evergreen forest, while Verrucomicrobia, an oligotrophic phylum, was more abundant in the broadleaved deciduous forest. The density of the correlation network of microbial OTUs was higher in the broadleaved deciduous forest but its modularity was smaller, reflecting lower resistance to environment changes. In addition, keystone OTUs of the broadleaved deciduous forest were mainly oligotrophic. Microbial functional genes associated with recalcitrant carbon degradation were also more abundant in the broadleaved deciduous forests, resulting in low accumulation of organic matters. Collectively, these findings revealed the important role of soil organic matter in shaping microbial taxonomic and functional traits. © 2015 John Wiley & Sons Ltd.

  9. [Microbial community and its activities in canopy- and understory humus of two montane forest types in Ailao Mountains, Northwest China].

    PubMed

    Liu, Yong-jie; Liu, Wen-yao; Chen, Lin; Zhang, Han-bo; Wang, Gao-sheng

    2010-09-01

    Mid-montane moist evergreen broadleaved forest (MMF) and top-montane dwarf mossy forest (DMF) are the two major natural forest types in subtropical mountainous area of Ailao Mountains, Northwest China. In this paper, a comparative study was made on the microbial composition, quantity, biochemical activity, metabolic activity, and their seasonal dynamics in the canopy- and understory humus of the two forest types. The composition, quantity, and metabolic activity of the microbes in the canopy humus of dominant tree species in MMF and DMF were also analyzed. In the canopy humus of the two forest types, the amounts of fungi and actinomycetes, microbial biomass C and N, and intensities of nitrogen fixation and cellulose decomposition were significantly higher than those in understory humus. Meanwhile, the amount of cellulose-decomposing microbes (ACDM), cellulose decomposition intensity, microbial biomass C and N, and metabolic activity in the canopy humus of MMF were significantly higher than those of DMF. The amounts of bacteria, fungi, and aerobic nitrogen-fixing bacteria (ANFB) and the metabolic activity in the canopy humus of MMF and DMF were significantly higher in wet season than in dry season, while a contradictory trend was observed on the amount of actinomycetes. No significant difference was observed on the amount of ACDM between wet season and dry season. For the two forest types, the amounts of microbes and their biochemical activities in canopy humus had a larger seasonal variation range than those in understory humus. There was a significant difference in the amounts of the microbes in canopy humus among the dominant tree species in MMF and DMF, especially in wet season. The microbes in canopy humus played important roles in maintaining the biodiversity of epiphytes in the canopy, and in supplying the needed nutrients for the vigorous growth of the epiphytes.

  10. Aerial photo guide to New England forest cover types

    Treesearch

    Rachel Riemann Hershey; William A. Befort

    1995-01-01

    NOTE large file size. Presents color infrared photos in stereo pairs for the identification of New England forest cover types. Depicts range maps, ecological relations, and range of composition for each forest cover type described. The guide is designed to assist the needs of interpreters of medium to large-scale color infrared aerial photography.

  11. Coniferous forest habitat types of central and southern Utah

    Treesearch

    Andrew P. Youngblood; Ronald L. Mauk

    1985-01-01

    A land-classification system based upon potential natural vegetation is presented for the coniferous forests of central and southern Utah. It is based on reconnaissance sampling of about 720 stands. A hierarchical taxonomic classification of forest sites was developed using the habitat type concept. Seven climax series, 37 habitat types, and six additional phases of...

  12. Food preferences of winter bird communities in different forest types.

    PubMed

    Renner, Swen C; Baur, Sofia; Possler, Astrid; Winkler, Julia; Kalko, Elisabeth K V; Bates, Paul J J; Mello, Marco A R

    2012-01-01

    Food availability for forest birds is a function of habitat type, forest management regime, and season. In winter, it is also impacted by variations in the weather. In the current study we assessed the food preferences of wild bird populations in two types of forest (spruce and beech) during the months of November 2010 to April 2011 in the Schwäbische Alb Biodiversity Exploratory, south-western Germany. Our aim was to investigate whether local bird communities preferred fat-rich, carbohydrate-rich or wild fruits and to determine how forest structure, seasonality and local weather conditions affected food preferences. We found higher bird activity in beech forests for the eleven resident species. We observed a clear preference for fat-rich food for all birds in both forest types. Snow cover affected activity at food stations but did not affect food preferences. Periods of extreme low temperatures increased activity.

  13. Food Preferences of Winter Bird Communities in Different Forest Types

    PubMed Central

    Renner, Swen C.; Baur, Sofia; Possler, Astrid; Winkler, Julia; Kalko, Elisabeth K. V.; Bates, Paul J. J.; Mello, Marco A. R.

    2012-01-01

    Food availability for forest birds is a function of habitat type, forest management regime, and season. In winter, it is also impacted by variations in the weather. In the current study we assessed the food preferences of wild bird populations in two types of forest (spruce and beech) during the months of November 2010 to April 2011 in the Schwäbische Alb Biodiversity Exploratory, south-western Germany. Our aim was to investigate whether local bird communities preferred fat-rich, carbohydrate-rich or wild fruits and to determine how forest structure, seasonality and local weather conditions affected food preferences. We found higher bird activity in beech forests for the eleven resident species. We observed a clear preference for fat-rich food for all birds in both forest types. Snow cover affected activity at food stations but did not affect food preferences. Periods of extreme low temperatures increased activity. PMID:23300878

  14. 29 CFR 780.1012 - Other evergreens.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Provisions Under Section 13(d) Requirements for Exemption § 780.1012 Other evergreens. The “other evergreens... the seasons of the year, such as laurel, ivy, yew, fir, and others. While plants other than...

  15. 29 CFR 780.1012 - Other evergreens.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Provisions Under Section 13(d) Requirements for Exemption § 780.1012 Other evergreens. The “other evergreens... the seasons of the year, such as laurel, ivy, yew, fir, and others. While plants other than...

  16. 29 CFR 780.1012 - Other evergreens.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Provisions Under Section 13(d) Requirements for Exemption § 780.1012 Other evergreens. The “other evergreens... the seasons of the year, such as laurel, ivy, yew, fir, and others. While plants other than...

  17. 29 CFR 780.1012 - Other evergreens.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Provisions Under Section 13(d) Requirements for Exemption § 780.1012 Other evergreens. The “other evergreens... the seasons of the year, such as laurel, ivy, yew, fir, and others. While plants other than...

  18. Accurate assessment of Congo basin forest carbon stocks requires forest type specific assessments

    NASA Astrophysics Data System (ADS)

    Moonen, Pieter C. J.; Van Ballaert, Siege; Verbist, Bruno; Boyemba, Faustin; Muys, Bart

    2014-05-01

    Due to a limited number of field-based studies estimations of carbon stocks in the Central Congo Basin remain highly uncertain. In particular, more information is needed about the variation in stocks between forest types and on the factors explaining these differences. This study presents results from biomass and soil carbon inventories in 46 0.25ha old-growth forest plots located in three study sites in Tshopo District, Democratic Republic of Congo. Four forest community types were identified using cluster and indicator species analysis based on the plots' large tree (>30cm DBH) species composition. Carbon stocks were calculated using newly established forest type specific tree height-diameter relationships to prevent errors related to the use of inappropriate regional relationships from literature. Using the Akaike criterion it became clear that for one site and a few forest types separate tree height-diameter relationships gave a robust and significant better fit, showing that there was a clear and significant interaction effect between sites and forest type. Mean above-ground carbon stocks were estimated at 165 ±44 Mg ha-1. Significant differences were found between forest types, but not between sites for a given forest type. Largest stocks were found in monodominant Gilbertiodendron dewevrei forests (187 ± 37 Mg C ha-1), which occurred in all sites. Smallest stocks (91 ± 14 Mg C ha-1) were found in the Margaritaria discoidea mixed forest type, which occurred only in one site, while two other mixed forest types showed intermediate stocks (148 ± 28 Mg C ha-1 and 160 ± 36 Mg C ha-1 respectively). The observed differences in aboveground stocks between forest types could be explained by forest structure related variables including number of large trees (DBH>70cm), average wood density and dominant height. When comparing the G. dewevrei monodominant type with mixed forest types within each study site, the former showed equal basal area and sometimes higher

  19. Net aboveground biomass declines of four major forest types with forest ageing and climate change in western Canada's boreal forests.

    PubMed

    Chen, Han Y H; Luo, Yong

    2015-10-01

    Biomass change of the world's forests is critical to the global carbon cycle. Despite storing nearly half of global forest carbon, the boreal biome of diverse forest types and ages is a poorly understood component of the carbon cycle. Using data from 871 permanent plots in the western boreal forest of Canada, we examined net annual aboveground biomass change (ΔAGB) of four major forest types between 1958 and 2011. We found that ΔAGB was higher for deciduous broadleaf (DEC) (1.44 Mg ha(-1)  year(-1) , 95% Bayesian confidence interval (CI), 1.22-1.68) and early-successional coniferous forests (ESC) (1.42, CI, 1.30-1.56) than mixed forests (MIX) (0.80, CI, 0.50-1.11) and late-successional coniferous (LSC) forests (0.62, CI, 0.39-0.88). ΔAGB declined with forest age as well as calendar year. After accounting for the effects of forest age, ΔAGB declined by 0.035, 0.021, 0.032 and 0.069 Mg ha(-1)  year(-1) per calendar year in DEC, ESC, MIX and LSC forests, respectively. The ΔAGB declines resulted from increased tree mortality and reduced growth in all forest types except DEC, in which a large biomass loss from mortality was accompanied with a small increase in growth. With every degree of annual temperature increase, ΔAGB decreased by 1.00, 0.20, 0.55 and 1.07 Mg ha(-1)  year(-1) in DEC, ESC, MIX and LSC forests, respectively. With every cm decrease of annual climatic moisture availability, ΔAGB decreased 0.030, 0.045 and 0.17 Mg ha(-1)  year(-1) in ESC, MIX and LSC forests, but changed little in DEC forests. Our results suggest that persistent warming and decreasing water availability have profound negative effects on forest biomass in the boreal forests of western Canada. Furthermore, our results indicate that forest responses to climate change are strongly dependent on forest composition with late-successional coniferous forests being most vulnerable to climate changes in terms of aboveground biomass. © 2015 John Wiley & Sons Ltd.

  20. Estimating canopy fuel parameters for Atlantic Coastal Plain forest types.

    SciTech Connect

    Parresol, Bernard, R.

    2007-01-15

    Abstract It is necessary to quantify forest canopy characteristics to assess crown fire hazard, prioritize treatment areas, and design treatments to reduce crown fire potential. A number of fire behavior models such as FARSITE, FIRETEC, and NEXUS require as input four particular canopy fuel parameters: 1) canopy cover, 2) stand height, 3) crown base height, and 4) canopy bulk density. These canopy characteristics must be mapped across the landscape at high spatial resolution to accurately simulate crown fire. Currently no models exist to forecast these four canopy parameters for forests of the Atlantic Coastal Plain, a region that supports millions of acres of loblolly, longleaf, and slash pine forests as well as pine-broadleaf forests and mixed species broadleaf forests. Many forest cover types are recognized, too many to efficiently model. For expediency, forests of the Savannah River Site are categorized as belonging to 1 of 7 broad forest type groups, based on composition: 1) loblolly pine, 2) longleaf pine, 3) slash pine, 4) pine-hardwood, 5) hardwood-pine, 6) hardwoods, and 7) cypress-tupelo. These 7 broad forest types typify forests of the Atlantic Coastal Plain region, from Maryland to Florida.

  1. Effects of simulated acid rain on soil and soil solution chemistry in a monsoon evergreen broad-leaved forest in southern China.

    PubMed

    Qiu, Qingyan; Wu, Jianping; Liang, Guohua; Liu, Juxiu; Chu, Guowei; Zhou, Guoyi; Zhang, Deqiang

    2015-05-01

    Acid rain is an environmental problem of increasing concern in China. In this study, a laboratory leaching column experiment with acid forest soil was set up to investigate the responses of soil and soil solution chemistry to simulated acid rain (SAR). Five pH levels of SAR were set: 2.5, 3.0, 3.5, 4.0, and 4.5 (as a control, CK). The results showed that soil acidification would occur when the pH of SAR was ≤3.5. The concentrations of NO₃(-)and Ca(2+) in the soil increased significantly when the pH of SAR fell 3.5. The concentration of SO₄(2-) in the soil increased significantly when the pH of SAR was <4.0. The effects of SAR on soil solution chemistry became increasingly apparent as the experiment proceeded (except for Na(+) and dissolved organic carbon (DOC)). The net exports of NO₃(-), SO₄(2-), Mg(2+), and Ca(2+) increased about 42-86% under pH 2.5 treatment as compared to CK. The Ca(2+) was sensitive to SAR, and the soil could release Ca(2+) through mineral weathering to mitigate soil acidification. The concentration of exchangeable Al(3+) in the soil increased with increasing the acidity of SAR. The releases of soluble Al and Fe were SAR pH dependent, and their net exports under pH 2.5 treatment were 19.6 and 5.5 times, respectively, higher than that under CK. The net export of DOC was reduced by 12-29% under SAR treatments as compared to CK. Our results indicate the chemical constituents in the soil are more sensitive to SAR than those in the soil solution, and the effects of SAR on soil solution chemistry depend not only on the intensity of SAR but also on the duration of SAR addition. The soil and soil solution chemistry in this region may not be affected by current precipitation (pH≈4.5) in short term, but the soil and soil leachate chemistry may change dramatically if the pH of precipitation were below 3.5 and 3.0, respectively.

  2. 29 CFR 780.1013 - Natural evergreens.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Natural evergreens. 780.1013 Section 780.1013 Labor... Provisions Under Section 13(d) Requirements for Exemption § 780.1013 Natural evergreens. Only “natural” evergreens may comprise the principal part of the wreath. The word “natural” qualifies all of the...

  3. 29 CFR 780.1012 - Other evergreens.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Other evergreens. 780.1012 Section 780.1012 Labor... Provisions Under Section 13(d) Requirements for Exemption § 780.1012 Other evergreens. The “other evergreens... the seasons of the year, such as laurel, ivy, yew, fir, and others. While plants other than...

  4. Succession of ground-dwelling beetle assemblages after fire in three habitat types in the Andean forest of NW Patagonia, Argentina.

    PubMed

    Sasal, Yamila; Raffaele, Estela; Farji-Brener, Alejandro G

    2010-01-01

    Wildfires are one of the major disturbances in the dynamics of forests and shrublands. However, little is known about their effects on insect communities that contribute to faunal biodiversity and play key roles in the ecosystem's dynamics. An intense and widespread fire occurred in 1999 in the Nahuel Huapi National Park in the Andean forest in northern Patagonia, Argentina. This fire affected adjacent, but different, habitat types. After the fire, beetle abundance, species richness and assemblage composition were compared among three habitats that were structurally different before the fire. These habitats were: 1) evergreen forest dominated by Nothofagus dombeyi (Mirb.) Oerst. (Fagales: Nothofagaceae), 2) a mixed forest of the evergreen conifer Austrocedrus chilensis (D. Don) Pic. Serm. and Bizzarri (Pinales: Cupressaceae) and N. dombeyi and 3) a shrubland with a diverse community of shrub species. The relationship between beetle diversity and vegetation structure was investigated over three consecutive years. Ground beetles were collected by pitfall traps, and plant species richness, vegetation cover, and height were measured. Beetle communities varied more over years between habitats during the early regeneration after fire. There was a shift in beetle assemblage composition with time after the fire in all habitat types, probably due to similar colonization rates and microclimatic conditions. Therefore, beetle succession was more influenced by recolonization and survivorship, accompanied by climatic conditions and recovery rate of plant communities over time, than it was influenced by pre-fire habitat conditions. These results suggest that in NW Patagonia, wildfire can have a substantial, short-term impact on beetle abundance and species composition. The pre-fire conditions of each habitat type determined the structure of post-fire communities of plants but not beetle assemblages. Wildfires produce simplification and homogenization of habitat types, and this

  5. Succession of Ground-Dwelling Beetle Assemblages After Fire in Three Habitat Types in the Andean Forest of NW Patagonia, Argentina

    PubMed Central

    Sasal, Yamila; Raffaele, Estela; Farji-Brener, Alejandro G.

    2010-01-01

    Wildfires are one of the major disturbances in the dynamics of forests and shrublands. However, little is known about their effects on insect communities that contribute to faunal biodiversity and play key roles in the ecosystem's dynamics. An intense and widespread fire occurred in 1999 in the Nahuel Huapi National Park in the Andean forest in northern Patagonia, Argentina. This fire affected adjacent, but different, habitat types. After the fire, beetle abundance, species richness and assemblage composition were compared among three habitats that were structurally different before the fire. These habitats were: 1) evergreen forest dominated by Nothofagus dombeyi (Mirb.) Oerst. (Fagales: Nothofagaceae), 2) a mixed forest of the evergreen conifer Austrocedrus chilensis (D. Don) Pic. Serm. and Bizzarri (Pinales: Cupressaceae) and N. dombeyi and 3) a shrubland with a diverse community of shrub species. The relationship between beetle diversity and vegetation structure was investigated over three consecutive years. Ground beetles were collected by pitfall traps, and plant species richness, vegetation cover, and height were measured. Beetle communities varied more over years between habitats during the early regeneration after fire. There was a shift in beetle assemblage composition with time after the fire in all habitat types, probably due to similar colonization rates and microclimatic conditions. Therefore, beetle succession was more influenced by recolonization and survivorship, accompanied by climatic conditions and recovery rate of plant communities over time, than it was influenced by pre-fire habitat conditions. These results suggest that in NW Patagonia, wildfire can have a substantial, short-term impact on beetle abundance and species composition. The pre-fire conditions of each habitat type determined the structure of post-fire communities of plants but not beetle assemblages. Wildfires produce simplification and homogenization of habitat types, and this

  6. Interpreting Michigan forest cover types from color infrared aerial photographs

    NASA Technical Reports Server (NTRS)

    Hudson, W. D.

    1984-01-01

    The characteristics of 17 cover types (13 forest types or tree species and 4 nonforest cover types) in Michigan are discussed as well as their interpretation from medium scale color infrared photography. The occurrence of each type is described by region and site requirements. Those attributes of a tree or stand which are helpful when attempting to interpret the type from a vertical perspective are discussed as well as common crown types. The identification of the forest type or tree species by using image characteristics (size, shape, shadow, color, texture, pattern, or association) is discussed. Ground photographs and sketches of individual trees are included. Stereograms of typical stands are available.

  7. Water sources of evergreen and deciduous species depend upon season, ecosystem type and snowpack depth in arctic tundra near Toolik Lake, Alaska

    NASA Astrophysics Data System (ADS)

    Ebbs, L. M.; Sullivan, P.; Welker, J. M.

    2010-12-01

    Arctic ecosystems are experiencing rapid increases in surface air temperatures, which are altering the hydrological cycle and its components. In the absence of increased precipitation, these changes will result in surface drying. Recent increases in the frequency and magnitude of tundra fires provide evidence that this change is already occurring. As temperature rises, active layers deepen and soils dry, plant-water relations will become an increasingly important component of the functioning of Arctic ecosystems (previously viewed as water-abundant). Arctic ecosystems are covered by snow for approximately 9 months and yet little is known about the importance of snowmelt as a water source for arctic plants. In this study, we examined seasonal variation in the water sources of two evergreen and two deciduous species in two ecosystems (tussock and dry heath tundra) in response to long-term experimental increases in snow depth. We analyzed δ18O and δD in xylem water and Δ18O, Δ13C and N concentration in leaf tissue reveal differences in water sources and in leaf gas exchange physiology. Our hypotheses were as follows: 1. Plants will use increasingly enriched water as the growing season progresses and the snowmelt water pool is diluted by rain, transpired and evaporatively enriched (increasing xylem water δ18O and δD); 2. Plants growing in tussock tundra will use more snowmelt water than plants growing in dry heath tundra (lower xylem water δ18O and δD), because snowmelt water will drain quickly from the porous soils of the dry heath; 3. Evergreen species will use more snowmelt water than deciduous species in both ecosystems because they initiate gas exchange earlier after snowmelt (lower xylem water δ18O and δD); 5. Plants in tussock tundra will be less water use-efficient than those in dry heath tundra and the difference will be greater for evergreen than deciduous species (greater leaf Δ13C); 6. Experimental snow additions will lead to lower water

  8. Fire ecology of the forest habitat types of northern Idaho

    Treesearch

    Jane Kapler Smith; William C. Fischer

    1997-01-01

    Provides information on fire ecology in forest habitat and community types occurring in northern Idaho. Identifies fire groups based on presettlement fire regimes and patterns of succession and stand development after fire. Describes forest fuels and suggests considerations for fire management.

  9. Carabid (Coleoptera) type collection at National Forest Insect Collection (NFIC), Forest Research Institute, Dehradun (India).

    PubMed

    Faisal, Mohammad; Singh, Sudhir

    2014-04-10

    Members of family Carabidae (Insecta: Coleoptera) are a dominant group of terrestrial predators. National Forest Insect Collection (NFIC) of Forest Research Institute, Dehradun (India) has a good collection of carabids rich in type material. Here we report the details of the type specimens of 139 species included in 49 genera, 24 tribes and 14 subfamilies. Colour automontaged photographs of each type along with its original labels are also included.

  10. Information system of forest growth and productivity by site quality type and elements of forest

    NASA Astrophysics Data System (ADS)

    Khlyustov, V.

    2012-04-01

    Information system of forest growth and productivity by site quality type and elements of forest V.K. Khlustov Head of the Forestry Department of Russian State Agrarian University named after K.A.Timiryazev doctor of agricultural sciences, professor The efficiency of forest management can be improved substantially by development and introduction of principally new models of forest growth and productivity dynamics based on regionalized site specific parameters. Therefore an innovative information system was developed. It describes the current state and gives a forecast for forest stand parameters: growth, structure, commercial and biological productivity depend on type of site quality. In contrast to existing yield tables, the new system has environmental basis: site quality type. The information system contains set of multivariate statistical models and can work at the level of individual trees or at the stand level. The system provides a graphical visualization, as well as export of the emulation results. The System is able to calculate detailed description of any forest stand based on five initial indicators: site quality type, site index, stocking, composition, and tree age by elements of the forest. The results of the model run are following parameters: average diameter and height, top height, number of trees, basal area, growing stock (total, commercial with distribution by size, firewood and residuals), live biomass (stem, bark, branches, foliage). The system also provides the distribution of mentioned above forest stand parameters by tree diameter classes. To predict the future forest stand dynamics the system require in addition the time slot only. Full set of forest parameters mention above will be provided by the System. The most conservative initial parameters (site quality type and site index) can be kept in the form of geo referenced polygons. In this case the system would need only 3 dynamic initial parameters (stocking, composition and age) to

  11. Ecophysiological responses to different forest patch type of two codominant tree seedlings

    PubMed Central

    Duan, Renyan; Huang, Minyi; Kong, Xiaoquan; Wang, Zhigao; Fan, Weiyi

    2015-01-01

    According to gap-phase dynamics theory, forests can be divided into four distinct patch types: gap patch (G), building patch (B), mature patch (M), and degeneration patch (D). Varying light conditions across patch types are one of the most important factors affecting the coexistence of vegetation. Mechanisms of coexistence can be understood through detailed knowledge of ecophysiological responses of codominant tree seedlings to patch types. The following study was conducted to determine ecophysiological responses of Cyclobalanopsis glauca (an evergreen broad-leaved species) and Bothrocaryum controversum (a deciduous broad-leaved species) to four different patch types. During the gap-phase dynamics, light intensity and the magnitude of change in the four different patches followed the order of: G > B > D > M. Both species had the greatest photosynthetic capacity in the G patch. Dry leaf mass per area (LMA), Chlorophyll a + b concentration (Chl), carotenoids (Car), and nitrogen content per area (Na) all responded to changes in light across patch type, but B. controversum showed greater sensitivity and changes than C. glauca. From G to M patch, the maximal quantum efficiency of PSII (Fv/Fm) had a larger variation magnitude for B. controversum than for C. glauca. From G to M patch, B. controversum showed significant changes in gas exchange, while C. glauca showed only small changes. Ecophysiological trait partitioning of response to light in different patches provides a possible explanation of a coexistence mechanism. PMID:25691956

  12. 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

  13. Forest succession on four habitat types in western Montana

    Treesearch

    Stephen F. Arno; Dennis G. Simmerman; Robert E. Keane

    1985-01-01

    Presents classifications of successional community types on four major forest habitat types in western Montana. Classifications show the sequences of seral community types developing after stand-replacing wildfire and clearcutting with broadcast burning, mechanical scarification, or no followup treatment. Information is provided for associating vegetational response to...

  14. A New Method for the Spatialization of Forest Cover by Fusing Forest Inventory and MODIS Data

    NASA Astrophysics Data System (ADS)

    Yin, Y.

    2015-12-01

    The acquisition of accurate spatial and temporal data on forest cover is the foundation for the sustainable management and utilization of forest resources. Although forest inventory data can provide accurate statistical information about forest type, such data do not give the specific spatial distribution. Remote sensing data provide accurate spatial information, and vegetation indices provide measures of land surface vegetation cover and growth conditions. By fusing these two sources of data, specific information about the spatial distribution of different types of forest can be obtained. Here, in a case study of Heilongjiang Province, we obtained forest dominant species area from the sixth and seventh national forest inventories and MODIS composite remote sensing data for the same periods to study forest cover by developing a spatialization method. Based on pixel features (such as NDVI and near-infrared reflectance) and their relationships with forest types, thresholds between different forest types in the remote sensing information were set according to the statistical data, which allowed the two sets of data to be fused. As a result, we generated forest cover maps for 2000 and 2005 that show the distribution of four forest types. Taking vegetation map of China as reference data, an error matrix analysis shows that the overall classification consistency reaches 76.7%, but only 70% for evergreen needleleaf forest and mixed forest. This study paves the way for further research on improving the accuracy of forest cover classification accuracy, on expanding the spatial and temporal scales of interest, and on quantifying forest dynamics

  15. Photosynthesis and carbon isotope discrimination in boreal forest ecosystems: A comparison of functional characteristics in plants from three mature forest types

    NASA Astrophysics Data System (ADS)

    Flanagan, Lawrence B.; Brooks, J. Renee; Ehleringer, James R.

    1997-12-01

    In this paper we compare measurements of photosynthesis and carbon isotope discrimination characteristics among plants from three mature boreal forest types (Black spruce, Jack pine, and aspen) in order to help explain variation in ecosystem-level gas exchange processes. Measurements were made at the southern study area (SSA) and northern study area (NSA) of the boreal forest in central Canada as part of the Boreal Ecosystem-Atmosphere Study (BOREAS). In both the NSA and the SSA there were significant differences in photosynthesis among the major tree species, with aspen having the highest CO2 assimilation rates and spruce the lowest. Within a species, photosynthetic rates in the SSA were approximately twice those measured in the NSA, and this was correlated with similar variations in stomatal conductance. Calculations of the ratio of leaf intercellular to ambient CO2 concentration (ci/ca) from leaf carbon isotope discrimination (Δ) values indicated a relatively low degree of stomatal limitation of photosynthesis, despite the low absolute values of stomatal conductance in these boreal tree species. Within each ecosystem, leaf Δ values were strongly correlated with life-form groups (trees, shrubs, forbs, and mosses), and these differences are maintained between years. Although we observed significant variation in the 13C content of tree rings at the old Jack pine site in the NSA during the past decade (indicating interannual variation in the degree of stomatal limitation), changes in summer precipitation and temperature accounted for only 44% of the isotopic variance. We scaled leaf-level processes to the ecosystem level through analyses of well-mixed canopy air. On average, all three forest types had similar ecosystem-level Δ values (average value ± standard deviation, 19.1‰±0.5‰), calculated from measurements of change in the concentration and carbon isotope ratio of atmospheric CO2 during a diurnal cycle within a forest canopy. However, there were

  16. Why are evergreen leaves so contrary about shade?

    PubMed

    Lusk, Christopher H; Reich, Peter B; Montgomery, Rebecca A; Ackerly, David D; Cavender-Bares, Jeannine

    2008-06-01

    Leaf mass per area (LMA) is one of the most widely measured of all plant functional traits. In deciduous forests, there is similarity between plastic and evolutionary responses of LMA to light gradients. In evergreens, however, LMA is lower in shaded than sunlit individuals of the same species, whereas shade-tolerant evergreens have higher LMA than light-demanders grown under the same conditions. We suggest that this pattern of 'counter-gradient variation' results from some combination of (i) close evolutionary coordination of LMA with leaf lifespan, (ii) selection for different leaf constitutions (relative investment in cell walls versus cell contents) in sun and shade environments and/or (iii) constraints on plasticity as a result of genetic correlations between phenotypes expressed in sun and shade.

  17. Markedly Divergent Tree Assemblage Responses to Tropical Forest Loss and Fragmentation across a Strong Seasonality Gradient

    PubMed Central

    Orihuela, Rodrigo L. L.; Peres, Carlos A.; Mendes, Gabriel; Jarenkow, João A.; Tabarelli, Marcelo

    2015-01-01

    We examine the effects of forest fragmentation on the structure and composition of tree assemblages within three seasonal and aseasonal forest types of southern Brazil, including evergreen, Araucaria, and deciduous forests. We sampled three southernmost Atlantic Forest landscapes, including the largest continuous forest protected areas within each forest type. Tree assemblages in each forest type were sampled within 10 plots of 0.1 ha in both continuous forests and 10 adjacent forest fragments. All trees within each plot were assigned to trait categories describing their regeneration strategy, vertical stratification, seed-dispersal mode, seed size, and wood density. We detected differences among both forest types and landscape contexts in terms of overall tree species richness, and the density and species richness of different functional groups in terms of regeneration strategy, seed dispersal mode and woody density. Overall, evergreen forest fragments exhibited the largest deviations from continuous forest plots in assemblage structure. Evergreen, Araucaria and deciduous forests diverge in the functional composition of tree floras, particularly in relation to regeneration strategy and stress tolerance. By supporting a more diversified light-demanding and stress-tolerant flora with reduced richness and abundance of shade-tolerant, old-growth species, both deciduous and Araucaria forest tree assemblages are more intrinsically resilient to contemporary human-disturbances, including fragmentation-induced edge effects, in terms of species erosion and functional shifts. We suggest that these intrinsic differences in the direction and magnitude of responses to changes in landscape structure between forest types should guide a wide range of conservation strategies in restoring fragmented tropical forest landscapes worldwide. PMID:26309252

  18. Markedly Divergent Tree Assemblage Responses to Tropical Forest Loss and Fragmentation across a Strong Seasonality Gradient.

    PubMed

    Orihuela, Rodrigo L L; Peres, Carlos A; Mendes, Gabriel; Jarenkow, João A; Tabarelli, Marcelo

    2015-01-01

    We examine the effects of forest fragmentation on the structure and composition of tree assemblages within three seasonal and aseasonal forest types of southern Brazil, including evergreen, Araucaria, and deciduous forests. We sampled three southernmost Atlantic Forest landscapes, including the largest continuous forest protected areas within each forest type. Tree assemblages in each forest type were sampled within 10 plots of 0.1 ha in both continuous forests and 10 adjacent forest fragments. All trees within each plot were assigned to trait categories describing their regeneration strategy, vertical stratification, seed-dispersal mode, seed size, and wood density. We detected differences among both forest types and landscape contexts in terms of overall tree species richness, and the density and species richness of different functional groups in terms of regeneration strategy, seed dispersal mode and woody density. Overall, evergreen forest fragments exhibited the largest deviations from continuous forest plots in assemblage structure. Evergreen, Araucaria and deciduous forests diverge in the functional composition of tree floras, particularly in relation to regeneration strategy and stress tolerance. By supporting a more diversified light-demanding and stress-tolerant flora with reduced richness and abundance of shade-tolerant, old-growth species, both deciduous and Araucaria forest tree assemblages are more intrinsically resilient to contemporary human-disturbances, including fragmentation-induced edge effects, in terms of species erosion and functional shifts. We suggest that these intrinsic differences in the direction and magnitude of responses to changes in landscape structure between forest types should guide a wide range of conservation strategies in restoring fragmented tropical forest landscapes worldwide.

  19. Methods for calculating forest ecosystem and harvested carbon with standard estimates for forest types of the United States

    Treesearch

    James E. Smith; Linda S. Heath; Kenneth E. Skog; Richard A. Birdsey

    2006-01-01

    This study presents techniques for calculating average net annual additions to carbon in forests and in forest products. Forest ecosystem carbon yield tables, representing stand-level merchantable volume and carbon pools as a function of stand age, were developed for 51 forest types within 10 regions of the United States. Separate tables were developed for...

  20. Forest discrimination with multipolarization imaging radar

    NASA Technical Reports Server (NTRS)

    Ford, J. P.; Wickland, D. E.

    1985-01-01

    The relations between polarization signatures and biophysical characteristics through a range of different forest environments were investigated using airborne synthetic-aperture (SAR) images acquired at L-band on March 1, 1984 in South Carolina. SAR data acquired in four linear polarization states with 10-m spatial resolution were encoded as color composite images and compared to US Forest Service forest stand data. The most useful correlative forest data were stand basal area, forest age, site condition index, and forest management type. It is found that the multipolarization images discriminate variation in tree density or difference in the amount of understory, but no evidence has been found for discrimination between evergreen and deciduous forest types.

  1. Biodiversity Analysis of Forest Litter Ant Assemblages in the Wayanad Region of Western Ghats Using Taxonomic and Conventional Diversity Measures

    PubMed Central

    Anu, Anto; Sabu, Thomas K.

    2007-01-01

    The diversity of litter ant assemblages in evergreen, deciduous and Shola evergreen (Shola) forest vegetation types of the Wayanad region of the Western Ghats was assessed employing conventional and taxonomic diversity indices. Non-dependence on quantitative data and the ability to relate the phylogenetic structure of assemblages with ecological conditions of the habitat, and to ascertain priorities for conservation of habitats, makes non-parametric taxonomic diversity measures, such as variation in taxonomic distinctness Λ+ and average taxonomic distinctness Δ+, highly useful tools for assessment of litter ant biodiversity. Although Δ+ values saturated leading to closer values for the 3 litter ant assemblages, Λ+ proved to be a more dependable index. Evenness in taxonomic spread was high in ant assemblages in deciduous forests and low in evergreen forests compared to the regional master list. Low Λ+ of ant assemblage in deciduous forests indicates that among the 3 forest vegetation types, deciduous forests provided the most favorable habitat conditions for litter ants. Low evenness, as is indicated by Λ+ in evergreen forests, was attributed to the presence of a group of taxonomically closely related ant assemblage more adapted to prevail in moist and wet ecological conditions. PMID:20334594

  2. Estimation of Stand Height and Forest Volume Using High Resolution Stereo Photography and Forest Type Map

    NASA Astrophysics Data System (ADS)

    Kim, K. M.

    2016-06-01

    Traditional field methods for measuring tree heights are often too costly and time consuming. An alternative remote sensing approach is to measure tree heights from digital stereo photographs which is more practical for forest managers and less expensive than LiDAR or synthetic aperture radar. This work proposes an estimation of stand height and forest volume(m3/ha) using normalized digital surface model (nDSM) from high resolution stereo photography (25cm resolution) and forest type map. The study area was located in Mt. Maehwa model forest in Hong Chun-Gun, South Korea. The forest type map has four attributes such as major species, age class, DBH class and crown density class by stand. Overlapping aerial photos were taken in September 2013 and digital surface model (DSM) was created by photogrammetric methods(aerial triangulation, digital image matching). Then, digital terrain model (DTM) was created by filtering DSM and subtracted DTM from DSM pixel by pixel, resulting in nDSM which represents object heights (buildings, trees, etc.). Two independent variables from nDSM were used to estimate forest stand volume: crown density (%) and stand height (m). First, crown density was calculated using canopy segmentation method considering live crown ratio. Next, stand height was produced by averaging individual tree heights in a stand using Esri's ArcGIS and the USDA Forest Service's FUSION software. Finally, stand volume was estimated and mapped using aerial photo stand volume equations by species which have two independent variables, crown density and stand height. South Korea has a historical imagery archive which can show forest change in 40 years of successful forest rehabilitation. For a future study, forest volume change map (1970s-present) will be produced using this stand volume estimation method and a historical imagery archive.

  3. Forest Management Type Influences Diversity and Community Composition of Soil Fungi across Temperate Forest Ecosystems

    PubMed Central

    Goldmann, Kezia; Schöning, Ingo; Buscot, François; Wubet, Tesfaye

    2015-01-01

    Fungal communities have been shown to be highly sensitive toward shifts in plant diversity and species composition in forest ecosystems. However, little is known about the impact of forest management on fungal diversity and community composition of geographically separated sites. This study examined the effects of four different forest management types on soil fungal communities. These forest management types include age class forests of young managed beech (Fagus sylvatica L.), with beech stands age of approximately 30 years, age class beech stands with an age of approximately 70 years, unmanaged beech stands, and coniferous stands dominated by either pine (Pinus sylvestris L.) or spruce (Picea abies Karst.) which are located in three study sites across Germany. Soil were sampled from 48 study plots and we employed fungal ITS rDNA pyrotag sequencing to assess the soil fungal diversity and community structure. We found that forest management type significantly affects the Shannon diversity of soil fungi and a significant interaction effect of study site and forest management on the fungal operational taxonomic units richness. Consequently distinct fungal communities were detected in the three study sites and within the four forest management types, which were mainly related to the main tree species. Further analysis of the contribution of soil properties revealed that C/N ratio being the most important factor in all the three study sites whereas soil pH was significantly related to the fungal community in two study sites. Functional assignment of the fungal communities indicated that 38% of the observed communities were Ectomycorrhizal fungi (ECM) and their distribution is significantly influenced by the forest management. Soil pH and C/N ratio were found to be the main drivers of the ECM fungal community composition. Additional fungal community similarity analysis revealed the presence of study site and management type specific ECM genera. This study extends our

  4. Forest Management Type Influences Diversity and Community Composition of Soil Fungi across Temperate Forest Ecosystems.

    PubMed

    Goldmann, Kezia; Schöning, Ingo; Buscot, François; Wubet, Tesfaye

    2015-01-01

    Fungal communities have been shown to be highly sensitive toward shifts in plant diversity and species composition in forest ecosystems. However, little is known about the impact of forest management on fungal diversity and community composition of geographically separated sites. This study examined the effects of four different forest management types on soil fungal communities. These forest management types include age class forests of young managed beech (Fagus sylvatica L.), with beech stands age of approximately 30 years, age class beech stands with an age of approximately 70 years, unmanaged beech stands, and coniferous stands dominated by either pine (Pinus sylvestris L.) or spruce (Picea abies Karst.) which are located in three study sites across Germany. Soil were sampled from 48 study plots and we employed fungal ITS rDNA pyrotag sequencing to assess the soil fungal diversity and community structure. We found that forest management type significantly affects the Shannon diversity of soil fungi and a significant interaction effect of study site and forest management on the fungal operational taxonomic units richness. Consequently distinct fungal communities were detected in the three study sites and within the four forest management types, which were mainly related to the main tree species. Further analysis of the contribution of soil properties revealed that C/N ratio being the most important factor in all the three study sites whereas soil pH was significantly related to the fungal community in two study sites. Functional assignment of the fungal communities indicated that 38% of the observed communities were Ectomycorrhizal fungi (ECM) and their distribution is significantly influenced by the forest management. Soil pH and C/N ratio were found to be the main drivers of the ECM fungal community composition. Additional fungal community similarity analysis revealed the presence of study site and management type specific ECM genera. This study extends our

  5. Different responses to shade of evergreen and deciduous oak seedlings and the effect of acorn size

    NASA Astrophysics Data System (ADS)

    Ke, Guo; Werger, Marinus J. A.

    1999-11-01

    An evergreen oak species, Cyclobalanopsis multinervis, and a deciduous oak species, Quercus aliena var. acuteserrata were grown from acorns under two light levels (full sunlight and shade at about 18 % of full sunlight, simulating the light intensities in forest clearings and gaps, respectively) for one growing season. Three hypotheses were tested: (i) the deciduous species grows faster than the evergreen species in forest gaps and clearings; (ii) the deciduous species responds more strongly in terms of growth and morphology to variation in light climate than the evergreen species; and (iii) seedling size is positively correlated to acorn size. The results showed: (i) at both light levels, the deciduous seedlings gained significantly more growth in biomass and height than the evergreen seedlings; (ii) both species produced significantly more biomass in full sunlight than in shade, without showing any significant difference in height between treatments. Increase in light intensity improved the growth of the deciduous seedlings more strongly; (iii) at a similar age, the deciduous seedlings showed a greater response in leaf morphology and biomass allocation to variation in light levels, but when compared at a similar size, biomass allocation patterns did not differ significantly between species; (iv) bigger acorns tended to produce larger seedlings, larger leaf sizes and more leaf area, between and within species. These differences demonstrate that the deciduous species is gap-dependent and has the advantage over the evergreen species in forest gaps and clearings.

  6. Songbird use of regenerating forest, glade, and edge habitat types

    Treesearch

    Alix D. Fink; Frank R., III Thompson; April A. Tudor

    2006-01-01

    Population numbers of many bird species associated with early-successional or disturbance-dependent habitat types are declining. We used an information-theoretic approach to evaluate hypotheses concerning factors affecting breeding bird densities in different early-successional habitat types. We studied shrubland bird communities in 3- to 5-year-old regenerating forest...

  7. Mapping forest succesion types in Siberia with Landsat data

    NASA Astrophysics Data System (ADS)

    Maksyutov, S. S.; Sedykh, V.; Kleptsova, I.; Frolov, A.; Silaev, A.; Kuzmenko, E.; Farber, S.; Kuzmik, N.; Sokolov, V. A.; Fedorov, A.; Nikolaeva, S.

    2013-12-01

    We develop a forest typology system based on dynamic vegetation approach and apply it to the analysis of the forest type distribution for several test areas in Siberia, aiming at capability of mapping whole Siberian forests based on Landsat data. Test region locations are: two in West Siberian middle taiga (Laryegan and Nyagan), one in Central Siberia and one in East Siberia near Yakutsk. The ground truth data are based on analysis of the field survey, forest inventory data from the point of view of the successional forest type classification. Supervised classification was applied to the areas covered with analysis of the ground truth and inventory data, using several limited area maps and vegetation survey transects published in literature. In Laryegan basin the upland forest areas are dominated (as climax forest species) by Scots pine on sandy soils and Siberian pine with presence of fir and spruce on the others. Those types are separable using Landsat spectral data alone. In the permafrost area around Yakutsk the most widespread succession type is birch to larch succession. Three stages of the birch to larch succession are detectable from Landsat image. When Landsat data is used in both West and East Siberia, distinction between deciduous broad-leaved species (birch, aspen, and willow) is difficult due to similarity in spectral signatures. Same problem exist for distinguishing between dark coniferous species (Siberian pine, fir and spruce). Image classification can be improved by applying landscape type analysis, such as separation into floodplain, terrace, sloping hills. Additional layers of information seem to be a promising way to complement Landsat data, including SAR-based biomass maps and terrain data

  8. Forest cover type analysis of New England forests using innovative WorldView-2 imagery

    NASA Astrophysics Data System (ADS)

    Kovacs, Jenna M.

    For many years, remote sensing has been used to generate land cover type maps to create a visual representation of what is occurring on the ground. One significant use of remote sensing is the identification of forest cover types. New England forests are notorious for their especially complex forest structure and as a result have been, and continue to be, a challenge when classifying forest cover types. To most accurately depict forest cover types occurring on the ground, it is essential to utilize image data that have a suitable combination of both spectral and spatial resolution. The WorldView-2 (WV2) commercial satellite, launched in 2009, is the first of its kind, having both high spectral and spatial resolutions. WV2 records eight bands of multispectral imagery, four more than the usual high spatial resolution sensors, and has a pixel size of 1.85 meters at the nadir. These additional bands have the potential to improve classification detail and classification accuracy of forest cover type maps. For this reason, WV2 imagery was utilized on its own, and in combination with Landsat 5 TM (LS5) multispectral imagery, to evaluate whether these image data could more accurately classify forest cover types. In keeping with recent developments in image analysis, an Object-Based Image Analysis (OBIA) approach was used to segment images of Pawtuckaway State Park and nearby private lands, an area representative of the typical complex forest structure found in the New England region. A Classification and Regression Tree (CART) analysis was then used to classify image segments at two levels of classification detail. Accuracies for each forest cover type map produced were generated using traditional and area-based error matrices, and additional standard accuracy measures (i.e., KAPPA) were generated. The results from this study show that there is value in analyzing imagery with both high spectral and spatial resolutions, and that WV2's new and innovative bands can be useful

  9. Unexpected presence of graminan- and levan-type fructans in the evergreen frost-hardy eudicot Pachysandra terminalis (Buxaceae): purification, cloning, and functional analysis of a 6-SST/6-SFT enzyme.

    PubMed

    Van den Ende, Wim; Coopman, Marlies; Clerens, Stefan; Vergauwen, Rudy; Le Roy, Katrien; Lammens, Willem; Van Laere, André

    2011-01-01

    About 15% of flowering plants accumulate fructans. Inulin-type fructans with β(2,1) fructosyl linkages typically accumulate in the core eudicot families (e.g. Asteraceae), while levan-type fructans with β(2,6) linkages and branched, graminan-type fructans with mixed linkages predominate in monocot families. Here, we describe the unexpected finding that graminan- and levan-type fructans, as typically occurring in wheat (Triticum aestivum) and barley (Hordeum vulgare), also accumulate in Pachysandra terminalis, an evergreen, frost-hardy basal eudicot species. Part of the complex graminan- and levan-type fructans as accumulating in vivo can be produced in vitro by a sucrose:fructan 6-fructosyltransferase (6-SFT) enzyme with inherent sucrose:sucrose 1-fructosyltransferase (1-SST) and fructan 6-exohydrolase side activities. This enzyme produces a series of cereal-like graminan- and levan-type fructans from sucrose as a single substrate. The 6-SST/6-SFT enzyme was fully purified by classic column chromatography. In-gel trypsin digestion led to reverse transcription-polymerase chain reaction-based cDNA cloning. The functionality of the 6-SST/6-SFT cDNA was demonstrated after heterologous expression in Pichia pastoris. Both the recombinant and native enzymes showed rather similar substrate specificity characteristics, including peculiar temperature-dependent inherent 1-SST and fructan 6-exohydrolase side activities. The finding that cereal-type fructans accumulate in a basal eudicot species further confirms the polyphyletic origin of fructan biosynthesis in nature. Our data suggest that the fructan syndrome in P. terminalis can be considered as a recent evolutionary event. Putative connections between abiotic stress and fructans are discussed.

  10. Unexpected Presence of Graminan- and Levan-Type Fructans in the Evergreen Frost-Hardy Eudicot Pachysandra terminalis (Buxaceae): Purification, Cloning, and Functional Analysis of a 6-SST/6-SFT Enzyme1[W

    PubMed Central

    Van den Ende, Wim; Coopman, Marlies; Clerens, Stefan; Vergauwen, Rudy; Le Roy, Katrien; Lammens, Willem; Van Laere, André

    2011-01-01

    About 15% of flowering plants accumulate fructans. Inulin-type fructans with β(2,1) fructosyl linkages typically accumulate in the core eudicot families (e.g. Asteraceae), while levan-type fructans with β(2,6) linkages and branched, graminan-type fructans with mixed linkages predominate in monocot families. Here, we describe the unexpected finding that graminan- and levan-type fructans, as typically occurring in wheat (Triticum aestivum) and barley (Hordeum vulgare), also accumulate in Pachysandra terminalis, an evergreen, frost-hardy basal eudicot species. Part of the complex graminan- and levan-type fructans as accumulating in vivo can be produced in vitro by a sucrose:fructan 6-fructosyltransferase (6-SFT) enzyme with inherent sucrose:sucrose 1-fructosyltransferase (1-SST) and fructan 6-exohydrolase side activities. This enzyme produces a series of cereal-like graminan- and levan-type fructans from sucrose as a single substrate. The 6-SST/6-SFT enzyme was fully purified by classic column chromatography. In-gel trypsin digestion led to reverse transcription-polymerase chain reaction-based cDNA cloning. The functionality of the 6-SST/6-SFT cDNA was demonstrated after heterologous expression in Pichia pastoris. Both the recombinant and native enzymes showed rather similar substrate specificity characteristics, including peculiar temperature-dependent inherent 1-SST and fructan 6-exohydrolase side activities. The finding that cereal-type fructans accumulate in a basal eudicot species further confirms the polyphyletic origin of fructan biosynthesis in nature. Our data suggest that the fructan syndrome in P. terminalis can be considered as a recent evolutionary event. Putative connections between abiotic stress and fructans are discussed. PMID:21037113

  11. 29 CFR 780.1011 - Evergreens.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Evergreens. 780.1011 Section 780.1011 Labor Regulations... Under Section 13(d) Requirements for Exemption § 780.1011 Evergreens. The material which must principally be used in making the wreaths is listed as “natural holly, pine, cedar, or other...

  12. 29 CFR 780.1011 - Evergreens.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Evergreens. 780.1011 Section 780.1011 Labor Regulations... Under Section 13(d) Requirements for Exemption § 780.1011 Evergreens. The material which must principally be used in making the wreaths is listed as “natural holly, pine, cedar, or other...

  13. 29 CFR 780.1011 - Evergreens.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Evergreens. 780.1011 Section 780.1011 Labor Regulations... Under Section 13(d) Requirements for Exemption § 780.1011 Evergreens. The material which must principally be used in making the wreaths is listed as “natural holly, pine, cedar, or other...

  14. 29 CFR 780.1011 - Evergreens.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Evergreens. 780.1011 Section 780.1011 Labor Regulations... Under Section 13(d) Requirements for Exemption § 780.1011 Evergreens. The material which must principally be used in making the wreaths is listed as “natural holly, pine, cedar, or other...

  15. 29 CFR 780.1011 - Evergreens.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Evergreens. 780.1011 Section 780.1011 Labor Regulations... Under Section 13(d) Requirements for Exemption § 780.1011 Evergreens. The material which must principally be used in making the wreaths is listed as “natural holly, pine, cedar, or other...

  16. Elm-ash-cottonwood forest type bibliography.

    Treesearch

    Stephen R Shifley; Kenneth M. Brown

    1978-01-01

    Lists 679 references, arranged by author's names, on the biology, ecology, silviculture and mensuration of the elm-ash-cottonwood type and its component species. Indices for species, subjects, and second authors are appended.

  17. Forest discrimination with multipolarization imaging radar

    NASA Technical Reports Server (NTRS)

    Ford, J. P.; Wickland, D. E.

    1985-01-01

    The use of radar polarization diversity for discriminating forest canopy variables on airborne synthetic-aperture radar (SAR) images is evaluated. SAR images were acquired at L-Band (24.6 cm) simultaneously in four linear polarization states (HH, HV, VH, and VV) in South Carolina on March 1, 1984. In order to relate the polarization signatures to biophysical properties, false-color composite images were compared to maps of forest stands in the timber compartment. In decreasing order, the most useful correlative forest data are stand basal area, forest age, site condition index, and forest management type. It is found that multipolarization images discriminate variation in tree density and difference in the amount of understory, but do not discriminate between evergreen and deciduous forest types.

  18. Age and distribution of an evergreen clonal shrub in the Coweeta basin: Rhododendron maximum L

    Treesearch

    Katherine J. Elliott; James M. Vose

    2012-01-01

    Rhododendron maximum L. is an evergreen, clonal shrub that forms a dominant sub-canopy layer and is a key species in southern Appalachian forests. We investigated the age and distribution of R. maximum across the Coweeta Basin, a 1626 ha watershed in western North Carolina. We selected 16 perennial, second-order streams and used a Global Positioning System to establish...

  19. Subtropical Forest Biomass Estimation Using Airborne LiDAR and Hyperspectral Data

    NASA Astrophysics Data System (ADS)

    Pang, Yong; Li, Zengyuan

    2016-06-01

    Forests have complex vertical structure and spatial mosaic pattern. Subtropical forest ecosystem consists of vast vegetation species and these species are always in a dynamic succession stages. It is very challenging to characterize the complexity of subtropical forest ecosystem. In this paper, CAF's (The Chinese Academy of Forestry) LiCHy (LiDAR, CCD and Hyperspectral) Airborne Observation System was used to collect waveform Lidar and hyperspectral data in Puer forest region, Yunnan province in the Southwest of China. The study site contains typical subtropical species of coniferous forest, evergreen broadleaf forest, and some other mixed forests. The hypersectral images were orthorectified and corrected into surface reflectance with support of Lidar DTM product. The fusion of Lidar and hyperspectral can classify dominate forest types. The lidar metrics improved the classification accuracy. Then forest biomass estimation was carried out for each dominate forest types using waveform Lidar data, which get improved than single Lidar data source.

  20. Habitat typing versus advanced vegetation classification in western forests

    Treesearch

    Tony Kusbach; John Shaw; James Long; Helga Van Miegroet

    2012-01-01

    Major habitat and community types in northern Utah were compared with plant alliances and associations that were derived from fidelity- and diagnostic-species classification concepts. Each of these classification approaches was associated with important environmental factors. Within a 20,000-ha watershed, 103 forest ecosystems were described by physiographic features,...

  1. Extrapolation of forest community types with a geographic information system

    Treesearch

    W.K. Clatterbuck; J. Gregory

    1991-01-01

    A geographic information system (GIS) was used to project eight forest community types from a 1,190-acre (482-ha) intensively sampled area to an unsampled 19,887-acre (8,054-ha) adjacent area with similar environments on the Western Highland Rim of Tennessee. Both physiographic and vegetative parameters were used to distinguish, extrapolate, and map communities.

  2. Status of growth and yield information for northern forest types

    Treesearch

    Dale S. Solomon

    1977-01-01

    Existing regional growth-and-yield information for most of the northern forest types is summarized by species. Present research is concentrated on growth-simulation models, constructed by either aggregating available information or through individual tree growth studies. A uniformity of more refined measurements is needed so that future growth models can be tried for...

  3. Cleridae (Insecta: Coleoptera) type collection at National Forest Insect Collection (NFIC), Forest Research Institute, Dehradun (India).

    PubMed

    Faisal, Mohammad; Singh, Sudhir; Yousuf, Mohammad

    2014-07-31

    Clerids are small predacious beetles (Coleoptera) that belong to the family Cleridae. In the National Forest Insect Collection (NFIC) Cleridae is represented by 31 authentically identified specimens including types of 27 species. The type material of Cleridae, deposited in the NFIC, Forest Research Institute, Dehradun (India), is listed and illustrated with digital automontage photographs. A list of 27 type species of Cleridae, 13 holotypes and 14 paratypes with information on species names, reference of the original publication, all available information on labels of types (country, locality, date of collection, collector name, etc) along with colored photographs of types and the labels that are attached to them, taken with Auto-montage 3-D imaging system, is provided. 

  4. Direct seeding in northern forest types

    Treesearch

    Ralph H. Griffin

    1977-01-01

    Two direct-seeding experiments were established to determine the effect of time of seeding (spring 1962 versus fall 1962), type of seedbed (prepared versus unprepared), and species (red pine (Pinus resinosa Ait.) versus white spruce (Picea glauca (Moench) Voss)) upon the success attained in the reforestation of a pine-barren site...

  5. Evaluating Landsat classification accuracy from forest cover-type maps

    NASA Technical Reports Server (NTRS)

    Hudson, W. D.

    1987-01-01

    The use of complete enumeration in the form of photointerpreted forest cover-type maps to evaluate the accuracy of Landsat classifications was compared with assessments made directly from the aerial photography. A computerized, geographic information system was utilized to compare the Landsat classifications with the cover-type maps on a pixel-by-pixel basis. Error maps of pixels which were similarly misclassified by a variety of algorithms contained a larger number of errors than were verified from the aerial photography. For the two test sites studied, only 67 and 52 percent of the pixels which were originally considered to be in error were substantiated as being in error. Discrepancies between the two results were primarily caused by definitional differences between the cover-type maps and the Landsat classifications, especially with regard to minimum-type size and crown closure estimates of forest land.

  6. What does it take to get family forest owners to enroll in a forest stewardship-type program?

    Treesearch

    Michael A. Kilgore; Stephanie A. Snyder; Joseph Schertz; Steven J. Taff

    2008-01-01

    We estimated the probability of enrollment and factors influencing participation in a forest stewardship-type program, Minnesota's Sustainable Forest Incentives Act, using data from a mail survey of over 1000 randomly-selected Minnesota family forest owners. Of the 15 variables tested, only five were significant predictors of a landowner's interest in...

  7. Revisiting Pearson's climate and forest type studies on the Fort Valley Experimental Forest

    Treesearch

    Joseph E. Crouse; Margaret M. Moore; Peter Fule

    2008-01-01

    Five weather station sites were established in 1916 by Fort Valley personnel along an elevational gradient from the Experimental Station to near the top of the San Francisco Peaks to investigate the factors that controlled and limited forest types. The stations were located in the ponderosa pine, Douglas-fir, limber pine, Engelmann spruce, and Engelmann spruce/...

  8. Revisiting Pearson's climate and forest type studies on the Fort Valley Experimental Forest (P-53)

    Treesearch

    Joseph E. Crouse; Margaret M. Moore; Peter Z. Fule

    2008-01-01

    Five weather station sites were established in 1916 by Fort Valley personnel along an elevational gradient from the Experimental Station to near the top of the San Francisco Peaks to investigate the factors that controlled and limited forest types. The stations were located in the ponderosa pine, Douglas-fir, limber pine, Engelmann spruce, and Engelmann spruce/...

  9. 29 CFR 780.1013 - Natural evergreens.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT Employment of... Exchange v. Industrial Accident Commission of Cal. 90 P. 2d 289) or evergreens which have been processed...

  10. 29 CFR 780.1013 - Natural evergreens.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT Employment of... Exchange v. Industrial Accident Commission of Cal. 90 P. 2d 289) or evergreens which have been processed...

  11. Secondhand Trees, Firsthand Learning. Holiday Evergreens Revitalized.

    ERIC Educational Resources Information Center

    Graves, C. John

    1990-01-01

    Described is an activity that uses discarded evergreen trees from Christmas. Tree age and growth characteristics are investigated by looking at the number of whorls and rings of the trunks. Extensions and follow-up activities are included. (KR)

  12. N : P Stoichiometry in a Forested Runoff during Storm Events: Comparisons with Regions and Vegetation Types

    PubMed Central

    Guo, Lanlan; Chen, Yi; Zhang, Zhao; Fukushima, Takehiko

    2012-01-01

    Nitrogen and phosphorus are considered the most important limiting elements in terrestrial and aquatic ecosystems. however, very few studies have focused on which is from forested streams, a bridge between these two systems. To fill this gap, we examined the concentrations of dissolved N and P in storm waters from forested watersheds of five regions in Japan, to characterize nutrient limitation and its potential controlling factors. First, dissolved N and P concentrations and the N : P ratio on forested streams were higher during storm events relative to baseflow conditions. Second, significantly higher dissolved inorganic N concentrations were found in storm waters from evergreen coniferous forest streams than those from deciduous broadleaf forest streams in Aichi, Kochi, Mie, Nagano, and with the exception of Tokyo. Finally, almost all the N : P ratios in the storm water were generally higher than 34, implying that the storm water should be P-limited, especially for Tokyo. PMID:22547978

  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.

  14. Estimating forest canopy attributes via airborne, high-resolution, multispectral imagery in midwest forest types

    NASA Astrophysics Data System (ADS)

    Gatziolis, Demetrios

    An investigation of the utility of high spatial resolution (sub-meter), 16-bit, multispectral, airborne digital imagery for forest land cover mapping in the heterogeneous and structurally complex forested landscapes of northern Michigan is presented. Imagery frame registration and georeferencing issues are presented and a novel approach for bi-directional reflectance distribution function (BRDF) effects correction and between-frame brightness normalization is introduced. Maximum likelihood classification of five cover type classes is performed over various geographic aggregates of 34 plots established in the study area that were designed according to the Forest Inventory and Analysis protocol. Classification accuracy estimates show that although band registration and BRDF corrections and brightness normalization provide an approximately 5% improvement over the raw imagery data, overall classification accuracy remains relatively low, barely exceeding 50%. Computed kappa coefficients reveal no statistical differences among classification trials. Classification results appear to be independent of geographic aggregations of sampling plots. Estimation of forest stand canopy parameter parameters (stem density, canopy closure, and mean crown diameter) is based on quantifying the spatial autocorrelation among pixel digital numbers (DN) using variogram analysis and slope break analysis, an alternative non-parametric approach. Parameter estimation and cover type classification proceed from the identification of tree apexes. Parameter accuracy assessment is evaluated via value comparison with a spatially precise set of field observations. In general, slope-break-based parameter estimates are superior to those obtained using variograms. Estimated root mean square errors at the plot level for the former average 6.5% for stem density, 3.5% for canopy closure and 2.5% for mean crown diameter, which are less than or equal to error rates obtained via traditional forest stand

  15. Mapping timing, extent, type and magnitude of disturbances across the national forest system, 1990–2011

    Treesearch

    Alexander Hernandez; Sean P. Healey; Chenquan Huang; R. Douglas. Ramsey

    2015-01-01

    As part of the U.S. Forest Service (USFS), National Forest System (NFS) comprehensive plan for carbon monitoring, a detailed temporal mapping of forest disturbances across all National Forests in the United States has been conducted. A long-term annual time series of data layers that show the timing, extent, type, and magnitude of disturbance beginning in 1990 and...

  16. Leaf economics of evergreen and deciduous tree species along an elevational gradient in a subtropical mountain

    PubMed Central

    Bai, Kundong; He, Chengxin; Wan, Xianchong; Jiang, Debing

    2015-01-01

    The ecophysiological mechanisms underlying the pattern of bimodal elevational distribution of evergreen tree species remain incompletely understood. Here we used leaf economics spectrum (LES) theory to explain such patterns. We measured leaf economic traits and constructed an LES for the co-existing 19 evergreen and 15 deciduous species growing in evergreen broad-leaved forest at low elevation, beech-mixed forest at middle elevation and hemlock-mixed forest at high elevation in Mao'er Mountain, Guangxi, Southern China (25°50′N, 110°49′E). Leaf economic traits presented low but significant phylogenetic signal, suggesting trait similarity between closely related species. After considering the effects of phylogenetic history, deciduous species in general showed a more acquisitive leaf strategy with a higher ratio of leaf water to dry mass, higher leaf nitrogen and phosphorous contents, higher photosynthetic and respiratory rates and greater photosynthetic nitrogen-use efficiency. In contrast, evergreen species exhibited a more conservative leaf strategy with higher leaf mass per area, greater construction costs and longer leaf life span. With the elevation-induced decreases of temperature and soil fertility, both evergreen and deciduous species showed greater resource conservation, suggesting the increasing importance of environmental filtering to community assembly with increasing elevation. We found close inter-specific correlations between leaf economic traits, suggesting that there are strong genetic constraints limiting the independent evolution of LES traits. Phylogenetic signal increased with decreasing evolutionary rate across leaf economic traits, suggesting that genetic constraints are important for the process of trait evolution. We found a significantly positive relationship between primary axis species score (PASS) distance and phylogenetic distance across species pairs and an increasing average PASS distance between evergreen and deciduous species

  17. [Frost-resistance of subtropical evergreen woody plants: an evaluation based on plant functional traits].

    PubMed

    Xu, Yi-Lu; Yang, Xiao-Dong; Xu, Yue; Xie, Yi-Ming; Wang, Liang-Yan; Yan, En-Rong

    2012-12-01

    Evaluating the frost-resistance of evergreen woody plants is of significance in guiding the species selection in forest management in subtropical region. In this paper, an investigation was made on the functional traits (including specific leaf area, stem wood density, leaf area, leaf dry matter content, leaf relative electrical conductance, and twig wood density) of 64 common evergreen broad-leaved and coniferous woody plant species in the Ningbo region of Zhejiang Province, East China, after a severe snowstorm in early 2008, aimed to select the evergreen woody plants with high ability of freeze-tolerance, and to establish a related evaluation system. By using a hierarchy analysis approach, the weight values of the functional traits of each species were determined, and an index system for evaluating the plants tolerance ability against freeze and mechanical damage was established. Based on this system, 23 evergreen plant species with high tolerance ability against freeze and mechanical damage, such as Cyclobalanopsis gilva, Cyclobalanopsis nubium, Neolitsea aurata, and Vacciniuim mandarinorum, were selected. In the meantime, on the basis of the ordering with each of the functional traits, the ordering of the tolerance ability of the 64 plant species against freeze and mechanical damage was made, and a list for the frost-resistance ability of the subtropical evergreen woody plant species in Ningbo region was constituted.

  18. Eradication effectiveness monitoring in Oregon tanoak forests

    Treesearch

    Ellen Michaels Goheen; Alan Kanaskie; Everett Hansen; Wendy Sutton; Paul Reeser; Nancy Osterbauer

    2010-01-01

    Phytophthora ramorum was first discovered in Oregon forests in July 2001 where it was killing tanoak (Lithocarpus densiflorus) and infecting Pacific rhododendron (Rhododendron macrophyllum) and evergreen huckleberry (Vaccinium ovatum). At that time, nine infested forest sites were...

  19. Forest vegetation in the Rocky Mountain and Intermountain regions: Habitat types and community types

    Treesearch

    Robert R. Alexander

    1988-01-01

    Habitat types and community types and their phases for the major forest tree species in the Rocky Mountain and Intermountain regions are tabulated. Included are the name(s), general location, elevation, relative site, successional status, principal tree and undergrowth associates, and the authority.

  20. Disturbance-mediated accelerated succession in two Michigan forest types

    USGS Publications Warehouse

    Abrams, Marc D.; Scott, Michael L.

    1989-01-01

    In northern lower Michigan, logging accelerated sugar maple (Acer saccharum) dominance in a northern white cedar (Thuja occidentals) community, and clear-cutting and burning quickly converted certain sites dominated by mature jack pine (Pinus banksiana) to early-succesional hardwoods, including Prunus, Populus, and Quercus. In both forest types the succeeding hardwoods should continue to increase in the future at the expense of the pioneer conifer species. In the cedar example, sugar maple was also increasing a an undisturbed, old-growth stand, but at a much reduced rate than in the logged stand. Traditionally, disturbance was through to set back succession to some earlier stage. However, out study sites and at least several other North American forest communities exhibited accelerated succession following a wide range of disturbances, including logging fire, ice storms, wind-throw, disease, insect attack, and herbicide spraying.

  1. Influence of Forest-Cover Types on Spring Thaw Timing in the Southern Boreal Forest

    NASA Astrophysics Data System (ADS)

    Ahmed, H. F.; Helgason, W.; Barr, A.; Black, T. A.

    2015-12-01

    The boreal forest is one of the largest of the world's biomes covering about 11% of its terrestrial surface and accounting for about 18% of its total terrestrial carbon pool. The timing of spring thaw, resulting in a lengthening or shortening of the growing season, has a strong influence on boreal forest productivity and associated carbon dioxide exchange with the atmosphere. A study of the influence of forest-cover type upon spring-thaw timing in the southern Canadian boreal forest has been undertaken using 18 years of soil temperature measurements at depths of 5, 10, 20, 50 and 100 cm. Soil was considered to be thawing during days of consistent near-zero soil temperature (daily mean of -0.5 to 0.5 °C and standard deviation of near zero). We compared the temporal pattern (first and last day) of soil thaw at three mature forest stands: trembling aspen, black spruce, and jack pine located in central Saskatchewan (~54°N, ~105°W). The soil freezing depth was deepest at the jack pine site (>100 cm) and shallowest at the black spruce site (<50 cm during most years). The mean last day of thaw at the 5-cm depth was earliest for the aspen site followed by jack pine and black spruce, respectively, with approximately 4 days difference among sites. Deeper in the soil profile, the trend of soil thaw remained in the same order, however, with much larger differences among sites: jack pine thawed 16 days later than aspen and black spruce thawed 18 days later than jack pine. Our analysis will relate the observed site differences in thaw timing to differences in site (soil and canopy) characteristics. Developing an improved understanding of the factors influencing the inter-annual and inter-site variability of soil thaw at these sites is required to appropriately characterize the ecological and hydrological responses of these sites to projected climate change.

  2. Fire ecology of Montana forest habitat types east of the Continental Divide

    Treesearch

    William C. Fischer; Bruce D. Clayton

    1983-01-01

    Provides information on fire as an ecological factor for forest habitat types occurring east of the Continental Divide in Montana. Identifies "Fire Groups" of habitat types based on fire's role in forest succession. Describes forest fuels and suggests considerations for fire management.

  3. Relating ring width of Mediterranean evergreen species to seasonal and annual variations of precipitation and temperature

    NASA Astrophysics Data System (ADS)

    Nijland, W.; Jansma, E.; Addink, E. A.; Domínguez Delmás, M.; de Jong, S. M.

    2011-05-01

    Plant growth in Mediterranean landscapes is limited by the typical summer-dry climate. Forests in these areas are only marginally productive and may be quite susceptible to modern climate change. To improve our understanding of forest sensitivity to annual and seasonal climatic variability, we use tree-ring measurements of two Mediterranean evergreen tree species: Quercus ilex L. and Arbutus unedo L. We sampled 34 stems of these species on three different types of substrates in the Peyne study area in southern France. The resulting chronologies were analysed in combination with 38 yr of monthly precipitation and temperature data to reconstruct the response of stem growth to climatic variability. Results indicate a strong positive response to May and June precipitation, as well as a significant positive influence of early-spring temperatures and a negative growth response to summer heat. Comparison of the data with more detailed productivity measurements in two contrasting years confirms these observations and shows a strong productivity limiting effect of low early-summer precipitation. The results show that tree-ring data from Q.ilex and A.unedo can provide valuable information about the response of these tree species to climate variability, improving our ability to predict the effects of climate change in Mediterranean ecosystems.

  4. Relating ring width of Mediterranean evergreen species to seasonal and annual variations of precipitation and temperature

    NASA Astrophysics Data System (ADS)

    Nijland, W.; Jansma, E.; Addink, E. A.; Domínguez Delmás, M.; de Jong, S. M.

    2011-01-01

    Plant growth in Mediterranean landscapes is limited by the typical summer-dry climate. Forests in these areas are only marginally productive and may be quite susceptible to modern climate change. To improve our understanding of forest sensitivity to annual and seasonal climatic variability, we use tree-ring measurements of two Mediterranean evergreen tree species: Quercus ilex and Arbutus unedo. We sampled 34 stems of these species on three different types of substrates in the Peyne study area in Southern France. The resulting chronologies were analysed in combination with 38 years of monthly precipitation and temperature data to reconstruct the response of stem growth to climatic variability. Results indicate a strong positive response to May and June precipitation, as well as a significant positive influence of early-spring temperatures and a negative growth response to summer heat. Comparison of the data with more detailed productivity measurements in two contrasting years confirms these observations and shows a strong productivity limiting effect of low early-summer precipitation. The results show that tree-ring data from Q. ilex and A. unedo can provide valuable information about the response of these tree species to climate variability, improving our ability to predict the effects of climate change in Mediterranean ecosystems.

  5. Forest Dynamics in the Eastern Ghats of Tamil Nadu, India

    NASA Astrophysics Data System (ADS)

    Jayakumar, S.; Ramachandran, A.; Bhaskaran, G.; Heo, J.

    2009-02-01

    The primary deciduous forests in the Eastern Ghats (EG) of Tamil Nadu (TN) India have undergone many changes owing to various need-based forest managements, such as timber extraction for industry, railway sleepers, charcoal, and forest clearance for hydroelectric projects and agriculture, during preindependence and postindependence periods (i.e., from 1800 to 1980). The enactment of a forest conservation act during the 1980s changed the perception of forest managers from utilization to conservation. This study was taken up to assess the forests dynamics in the EG of TN spatially between 1990 and 2003 and nonspatially between 1900 and the 1980s. Landsat Thematic Mapper (TM) and Indian Remote Sensing satellite (IRS) 1D Linear Imaging and Self Scanning (LISS III) data were used to assess forests during 1990 and 2003, respectively. Field floristic survey and secondary data (such as published literature, floras, books, and forest working plans) were used to assess the forest dynamics in terms of forest type and species composition among the preindependence period, the postindependence period, and the present (i.e., before and after 1980). The satellite data analysis revealed a considerable amount of changes in all forest types during the 13 years. The comparison of species composition and forest types between the past and present revealed that need-based forest management along with anthropogenic activity have altered the primary deciduous forest in to secondary and postextraction secondary forests such as southern thorn and southern thorn scrub forests in the middle [400-900 m above mean sea level (MSL)] and lower slopes (<400 m MSL). However, the evergreen forests present at the upper slope (>900 m MSL) and plateau seemed not to be much affected by the forest management. The changes estimated by the satellite data processing in the major forest types such as evergreen, deciduous, southern thorn, and southern thorn scrub are really alarming because these changes have

  6. Forest dynamics in the Eastern Ghats of Tamil Nadu, India.

    PubMed

    Jayakumar, S; Ramachandran, A; Bhaskaran, G; Heo, J

    2009-02-01

    The primary deciduous forests in the Eastern Ghats (EG) of Tamil Nadu (TN) India have undergone many changes owing to various need-based forest managements, such as timber extraction for industry, railway sleepers, charcoal, and forest clearance for hydroelectric projects and agriculture, during preindependence and postindependence periods (i.e., from 1800 to 1980). The enactment of a forest conservation act during the 1980s changed the perception of forest managers from utilization to conservation. This study was taken up to assess the forests dynamics in the EG of TN spatially between 1990 and 2003 and nonspatially between 1900 and the 1980s. Landsat Thematic Mapper (TM) and Indian Remote Sensing satellite (IRS) 1D Linear Imaging and Self Scanning (LISS III) data were used to assess forests during 1990 and 2003, respectively. Field floristic survey and secondary data (such as published literature, floras, books, and forest working plans) were used to assess the forest dynamics in terms of forest type and species composition among the preindependence period, the postindependence period, and the present (i.e., before and after 1980). The satellite data analysis revealed a considerable amount of changes in all forest types during the 13 years. The comparison of species composition and forest types between the past and present revealed that need-based forest management along with anthropogenic activity have altered the primary deciduous forest in to secondary and postextraction secondary forests such as southern thorn and southern thorn scrub forests in the middle [400-900 m above mean sea level (MSL)] and lower slopes (<400 m MSL). However, the evergreen forests present at the upper slope (>900 m MSL) and plateau seemed not to be much affected by the forest management. The changes estimated by the satellite data processing in the major forest types such as evergreen, deciduous, southern thorn, and southern thorn scrub are really alarming because these changes have

  7. Forest type mapping using incorporation of spatial models and ETM+ data.

    PubMed

    Joibary, Shaban Shataee; Darvishsefat, Ali A; Kellenberger, Tobias W

    2007-07-15

    Results of former researches have shown that spectrally based analysis alone could not satisfy forest type classification in mountainous mixed forests. Forest type based on composed different parameters such as topography elements like aspect, elevation and slop. These elements that are affected on occurrences of forest type can be stated as spatial distribution models. Using ancillary data integrated with spectral data could help to separate forest type. In order to find the abilities of using topographic spatial predictive models to improve forest type classification, an investigation was carried out to classify forest type using ETM+ data in a part of northern forests of Iran. The Tasseled Cap, Ratioing transformations and Principal Component Analysis were applied to the spectral bands. The best spectral and predictive data sets for classifying forest type using maximum likelihood classification were chosen using the Bhattacharya seperability index. Primary analysis between forest type and topographic parameters showed that elevation and aspect are most correlated with the occurrences of type. Probability occurrence rates of forest type were extracted in the aspect; elevation, integrated aspect and elevation as well as homogeneous units structured on elevation and aspect classes. Based on occurrence rates of forest type, spatial predictive distribution models were generated for each type individually. Classification of the best spectral data sets was accomplished by maximum likelihood classifier and using these spatial predictive models. Results were assessed using a sample ground truth of forest type. This study showed that spatial predictive models could considerably improve the results compared with spectral data alone from 49 to 60%. Among spatial models used, the spatial predictive models constructed based on the homogeneous units could improve results in comparison to other models. Applying other parameters related to forest type like soil maps would

  8. Sub-biome variability in the biophysical influence of forests on climate using the Community Earth System Model

    NASA Astrophysics Data System (ADS)

    Ahlswede, B.; Thomas, R. Q.

    2014-12-01

    Forests influence local climate through biophysical processes. It is well established that boreal forests have a warming effect by reducing albedo and tropical forests have a cooling effect due to increased evapotranspiration. However the influence of temperate forests on climate is less certain. Previous model experiments have shown the average effect of temperate forests as a whole to be a weak warming effect. However, some non-model studies that examine these effects at the sub-biome level show a latitudinal gradient of effects presumably due to differences in climate; while other studies show variation in biophysical effects due to forest type that is independent of latitude. Using the Community Earth System Model, we explore spatial variation in the direction and magnitude of the climate response to simulated deforestation in temperate forests. Our analysis focuses on the relative importance of pre-deforestation temperature, pre-deforestation precipitation, and the percentage of a grid cell occupied by needle-leaf evergreen trees as factors explaining how deforestation influences climate. We use results from deforestation simulations where forests are subdivided into temperature and precipitation clusters to develop a statistical model that predicts the change in regional air temperature, precipitation, and relative humidity based on climate. To examine the sensitivity of results to the plant-type we repeated the simulations of deforestation in the climate clusters using two pre-deforestation forest compositions: 100% needle-leaf evergreen trees (0 % broad-leaf deciduous) and 0% needle-leaf evergreen trees (100 % broad-leaf deciduous). Overall, we found that within the temperate forests warmer, wetter forests cooled climate while cooler, wetter forests warmed climate. The influence of plant-type was most pronounced in cooler regions. Our results help better understand how land-cover change in the temperate region influences climate and highlights how changes

  9. Redefining plant functional types for forests based on plant traits

    NASA Astrophysics Data System (ADS)

    Wei, L.; Xu, C.; Christoffersen, B. O.; McDowell, N. G.; Zhou, H.

    2016-12-01

    Our ability to predict forest mortality is limited by the simple plant functional types (PFTs) in current generations of Earth System models (ESMs). For example, forests were formerly separated into PFTs only based on leaf form and phenology across different regions (arctic, temperate, and tropic areas) in the Community Earth System Model (CESM). This definition of PFTs ignored the large variation in vulnerability of species to drought and shade tolerance within each PFT. We redefined the PFTs for global forests based on plant traits including phenology, wood density, leaf mass per area, xylem-specific conductivity, and xylem pressure at 50% loss of conductivity. Species with similar survival strategies were grouped into the same PFT. New PFTs highlighted variation in vulnerability and physiological adaptation to drought and shade. New PFTs were better clustered than old ones in the two-dimensional plane of the first two principle components in a principle component analysis. We expect that the new PFTs will strengthen ESMs' ability on predicting drought-induced mortality in the future.

  10. Divergence in Forest-Type Response to Climate and Weather: Evidence for Regional Links Between Forest-Type Evenness and Net Primary Productivity

    USGS Publications Warehouse

    Bradford, J.B.

    2011-01-01

    Climate change is altering long-term climatic conditions and increasing the magnitude of weather fluctuations. Assessing the consequences of these changes for terrestrial ecosystems requires understanding how different vegetation types respond to climate and weather. This study examined 20 years of regional-scale remotely sensed net primary productivity (NPP) in forests of the northern Lake States to identify how the relationship between NPP and climate or weather differ among forest types, and if NPP patterns are influenced by landscape-scale evenness of forest-type abundance. These results underscore the positive relationship between temperature and NPP. Importantly, these results indicate significant differences among broadly defined forest types in response to both climate and weather. Essentially all weather variables that were strongly related to annual NPP displayed significant differences among forest types, suggesting complementarity in response to environmental fluctuations. In addition, this study found that forest-type evenness (within 8 ?? 8 km2 areas) is positively related to long-term NPP mean and negatively related to NPP variability, suggesting that NPP in pixels with greater forest-type evenness is both higher and more stable through time. This is landscape- to subcontinental-scale evidence of a relationship between primary productivity and one measure of biological diversity. These results imply that anthropogenic or natural processes that influence the proportional abundance of forest types within landscapes may influence long-term productivity patterns. ?? 2011 Springer Science+Business Media, LLC (outside the USA).

  11. Woodpecker abundance and habitat use in three forest types in eastern Texas

    Treesearch

    Clifford E. Shackelford; Richard N. Conner

    1997-01-01

    Woodpeckers were censused in 60 fixed-radius (300 m) circular plots (divided into eight 45B-arc pie-shaped sectors) in mature forests (60 to 80 years-old) of three forest types (20 plots per type) in eastern Texas: bottomland hardwood forest; longleaf pine (Pinus palustris) savanna; and mixed pine-hardwood forest. A total of 2,242 individual woodpeckers of eight...

  12. Detailed maps of tropical forest types are within reach: forest tree communities for Trinidad and Tobago mapped with multiseason Landsat and multiseason fine-resolution imagery

    Treesearch

    Eileen H. Helmer; Thomas S. Ruzycki; Jay Benner; Shannon M. Voggesser; Barbara P. Scobie; Courtenay Park; David W. Fanning; Seepersad. Ramnarine

    2012-01-01

    Tropical forest managers need detailed maps of forest types for REDD+, but spectral similarity among forest types; cloud and scan-line gaps; and scarce vegetation ground plots make producing such maps with satellite imagery difficult. How can managers map tropical forest tree communities with satellite imagery given these challenges? Here we describe a case study of...

  13. Stocking, Forest Type, and Stand Size Class - The Southern Forest Inventory and Analysis Unit's Calculation of Three Important Stand Descriptors

    Treesearch

    Dennis M. May

    1990-01-01

    The procedures by which the Southern Forest Inventory and Analysis unit calculates stocking from tree data collected on inventory sample plots are described in this report. Stocking is then used to ascertain two other important stand descriptors: forest type and stand size class. Inventory data for three plots from the recently completed 1989 Tennessee survey are used...

  14. Forest cover type, habitat diversity, and anthropogenic influences on forest ecosystems adjoining the Maasai Mara National Reserve, Kenya

    Treesearch

    James Legilisho-Kiyiapi

    2000-01-01

    Through combined use of satellite imagery, aerial photographs, and ground truthing, a multilevel assessment was conducted in a forest block that forms a unique dispersal zone to the Maasai Mara National Reserve ecosystem. Results of the survey revealed considerable ecological diversity on an area-scale basis - in terms of ecotypes. Forest types ranged from Afro-montane...

  15. DISGUISED IN AN OCEANIC CAMOUFLAGE PAINT SCHEME, EVERGREEN MAKES HER ...

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

    DISGUISED IN AN OCEANIC CAMOUFLAGE PAINT SCHEME, EVERGREEN MAKES HER WAY THROUGH THE NORTH ATLANTIC DURING WORLD WAR II. HER 3" GUN IS VISIBLE BEHIND THE STACK - U.S. Coast Guard Cutter EVERGREEN, New London, New London County, CT

  16. Photo series for quantifying forest residues in the: sierra mixed conifer type, sierra true fir type.

    Treesearch

    W.G. Maxwell; F.R. Ward

    1979-01-01

    Five series of photographs display different forest residue loading levels, by size classes, for areas of like timber type (Sierra mixed conifer and Sierra true fir) and cutting objective. Information with each photo includes measured weights, volumes and other residue data, information about the timber stand and harvest actions, and assessment of fire behavior and...

  17. Review of forest landscape models: types, methods, development and applications

    Treesearch

    Weimin Xi; Robert N. Coulson; Andrew G. Birt; Zong-Bo Shang; John D. Waldron; Charles W. Lafon; David M. Cairns; Maria D. Tchakerian; Kier D. Klepzig

    2009-01-01

    Forest landscape models simulate forest change through time using spatially referenced data across a broad spatial scale (i.e. landscape scale) generally larger than a single forest stand. Spatial interactions between forest stands are a key component of such models. These models can incorporate other spatio-temporal processes such as...

  18. Seedling functional types in a lowland rain forest in Mexico.

    PubMed

    Ibarra-Manríquez, G; Martínez Ramos, M; Oyama, K

    2001-10-01

    Seedling morphology of 210 species (173 trees and 37 lianas) was studied from a community perspective to identify major patterns of seedling functional types in a Mexican rain forest. Five types of seedlings were distinguished: cryptocotylar with reserve storage or absorption cotyledons (epigeal [CER] and hypogeal [CHR]), phanerocotylar epigeal, either with photosynthetic cotyledons (PEF) or with reserve storage or absorption cotyledons (PER), and phanerocotylar hypogeal with reserve cotyledons (PHR). The most common seedling type was PEF (49.5%), followed by CHR (31.4%), PER (9.5%), PHR (7.2%), and CER (2.4%). Excepting the CER type, seedling type frequencies did not differ between trees and lianas. The PEF seedlings had the lightest seeds, whereas CHR seedlings had the heaviest ones. Pioneer trees showed lighter seeds than persistent trees or lianas in species with PEF but not in species with PER. Pioneer trees (38 species) showed three seedling types and the most common was PEF (82%). Persistent trees (135 species) showed the five seedling types but PEF (43%) and CHR (37%) were the most frequent. Seedling type frequencies differed among dispersal syndrome groups. The animal dispersal syndrome was significantly more frequent in species with CHR. Our results show an evolutionary convergence of seedling types at the community level worldwide and the existence of a phylogenetic inertia in the evolution of initial seedling morphology. A comparison among eight tropical communities indicated on average that PEF is the most frequent type and CER the least common, although the relative frequency of each seedling type differs among communities, particularly between Neotropical and Paleotropical sites.

  19. Types and rates of forest disturbance in Brazilian Legal Amazon, 2000–2013

    PubMed Central

    Tyukavina, Alexandra; Hansen, Matthew C.; Potapov, Peter V.; Stehman, Stephen V.; Smith-Rodriguez, Kevin; Okpa, Chima; Aguilar, Ricardo

    2017-01-01

    Deforestation rates in primary humid tropical forests of the Brazilian Legal Amazon (BLA) have declined significantly since the early 2000s. Brazil’s national forest monitoring system provides extensive information for the BLA but lacks independent validation and systematic coverage outside of primary forests. We use a sample-based approach to consistently quantify 2000–2013 tree cover loss in all forest types of the region and characterize the types of forest disturbance. Our results provide unbiased forest loss area estimates, which confirm the reduction of primary forest clearing (deforestation) documented by official maps. By the end of the study period, nonprimary forest clearing, together with primary forest degradation within the BLA, became comparable in area to deforestation, accounting for an estimated 53% of gross tree cover loss area and 26 to 35% of gross aboveground carbon loss. The main type of tree cover loss in all forest types was agroindustrial clearing for pasture (63% of total loss area), followed by small-scale forest clearing (12%) and agroindustrial clearing for cropland (9%), with natural woodlands being directly converted into croplands more often than primary forests. Fire accounted for 9% of the 2000–2013 primary forest disturbance area, with peak disturbances corresponding to droughts in 2005, 2007, and 2010. The rate of selective logging exploitation remained constant throughout the study period, contributing to forest fire vulnerability and degradation pressures. As the forest land use transition advances within the BLA, comprehensive tracking of forest transitions beyond primary forest loss is required to achieve accurate carbon accounting and other monitoring objectives. PMID:28439536

  20. Types and rates of forest disturbance in Brazilian Legal Amazon, 2000-2013.

    PubMed

    Tyukavina, Alexandra; Hansen, Matthew C; Potapov, Peter V; Stehman, Stephen V; Smith-Rodriguez, Kevin; Okpa, Chima; Aguilar, Ricardo

    2017-04-01

    Deforestation rates in primary humid tropical forests of the Brazilian Legal Amazon (BLA) have declined significantly since the early 2000s. Brazil's national forest monitoring system provides extensive information for the BLA but lacks independent validation and systematic coverage outside of primary forests. We use a sample-based approach to consistently quantify 2000-2013 tree cover loss in all forest types of the region and characterize the types of forest disturbance. Our results provide unbiased forest loss area estimates, which confirm the reduction of primary forest clearing (deforestation) documented by official maps. By the end of the study period, nonprimary forest clearing, together with primary forest degradation within the BLA, became comparable in area to deforestation, accounting for an estimated 53% of gross tree cover loss area and 26 to 35% of gross aboveground carbon loss. The main type of tree cover loss in all forest types was agroindustrial clearing for pasture (63% of total loss area), followed by small-scale forest clearing (12%) and agroindustrial clearing for cropland (9%), with natural woodlands being directly converted into croplands more often than primary forests. Fire accounted for 9% of the 2000-2013 primary forest disturbance area, with peak disturbances corresponding to droughts in 2005, 2007, and 2010. The rate of selective logging exploitation remained constant throughout the study period, contributing to forest fire vulnerability and degradation pressures. As the forest land use transition advances within the BLA, comprehensive tracking of forest transitions beyond primary forest loss is required to achieve accurate carbon accounting and other monitoring objectives.

  1. Potential change in forest types and stand heights in central Siberia in a warming climate

    NASA Astrophysics Data System (ADS)

    Tchebakova, N. M.; Parfenova, E. I.; Korets, M. A.; Conard, S. G.

    2016-03-01

    Previous regional studies in Siberia have demonstrated climate warming and associated changes in distribution of vegetation and forest types, starting at the end of the 20th century. In this study we used two regional bioclimatic envelope models to simulate potential changes in forest types distribution and developed new regression models to simulate changes in stand height in tablelands and southern mountains of central Siberia under warming 21st century climate. Stand height models were based on forest inventory data (2850 plots). The forest type and stand height maps were superimposed to identify how heights would change in different forest types in future climates. Climate projections from the general circulation model Hadley HadCM3 for emission scenarios B1 and A2 for 2080s were paired with the regional bioclimatic models. Under the harsh A2 scenario, simulated changes included: a 80%-90% decrease in forest-tundra and tundra, a 30% decrease in forest area, a ˜400% increase in forest-steppe, and a 2200% increase in steppe, forest-steppe and steppe would cover 55% of central Siberia. Under sufficiently moist conditions, the southern and middle taiga were simulated to benefit from 21st century climate warming. Habitats suitable for highly-productive forests (≥30-40 m stand height) were simulated to increase at the expense of less productive forests (10-20 m). In response to the more extreme A2 climate the area of these highly-productive forests would increase 10%-25%. Stand height increases of 10 m were simulated over 35%-50% of the current forest area in central Siberia. In the extremely warm A2 climate scenario, the tall trees (25-30 m) would occur over 8%-12% of area in all forest types except forest-tundra by the end of the century. In forest-steppe, trees of 30-40 m may cover some 15% of the area under sufficient moisture.

  2. Governance and Decision-Making at Evergreen.

    ERIC Educational Resources Information Center

    Evergreen State Coll., Olympia, Washington.

    This document presents a description of the process of governance and decisionmaking at Evergreen State University. The system: (1) calls for the continuous flow of information and for the effective keeping of necessary records; (2) provides for getting the work done and for making decisions where the action is; (3) allows for creative policy…

  3. Evergreen: Profile of a New College.

    ERIC Educational Resources Information Center

    Coombs, Don H.; Prevel, James J.

    Evergreen State College is an unprecedented flexible, sophisticated educational instrument designed to avoid depersonalization. Students are treated as responsible adults and are expected to work closely, as colleagues, with their teachers. Curriculum planning reflects the belief that graduates would change their career pattern and life styles at…

  4. 'Linkage' pharmaceutical evergreening in Canada and Australia.

    PubMed

    Faunce, Thomas A; Lexchin, Joel

    2007-06-01

    'Evergreening' is not a formal concept of patent law. It is best understood as a social idea used to refer to the myriad ways in which pharmaceutical patent owners utilise the law and related regulatory processes to extend their high rent-earning intellectual monopoly privileges, particularly over highly profitable (either in total sales volume or price per unit) 'blockbuster' drugs. Thus, while the courts are an instrument frequently used by pharmaceutical brand name manufacturers to prolong their patent royalties, 'evergreening' is rarely mentioned explicitly by judges in patent protection cases. The term usually refers to threats made to competitors about a brand-name manufacturer's tactical use of pharmaceutical patents (including over uses, delivery systems and even packaging), not to extension of any particular patent over an active product ingredient. This article focuses in particular on the 'evergreening' potential of so-called 'linkage' provisions, imposed on the regulatory (safety, quality and efficacy) approval systems for generic pharmaceuticals of Canada and Australia, by specific articles in trade agreements with the US. These 'linkage' provisions have also recently appeared in the Korea-US Free Trade Agreement (KORUSFTA). They require such drug regulators to facilitate notification of, or even prevent, any potential patent infringement by a generic pharmaceutical manufacturer. This article explores the regulatory lessons to be learnt from Canada's and Australia's shared experience in terms of minimizing potential adverse impacts of such 'linkage evergreening' provisions on drug costs and thereby potentially on citizen's access to affordable, essential medicines.

  5. 'Linkage' pharmaceutical evergreening in Canada and Australia

    PubMed Central

    Faunce, Thomas A; Lexchin, Joel

    2007-01-01

    'Evergreening' is not a formal concept of patent law. It is best understood as a social idea used to refer to the myriad ways in which pharmaceutical patent owners utilise the law and related regulatory processes to extend their high rent-earning intellectual monopoly privileges, particularly over highly profitable (either in total sales volume or price per unit) 'blockbuster' drugs. Thus, while the courts are an instrument frequently used by pharmaceutical brand name manufacturers to prolong their patent royalties, 'evergreening' is rarely mentioned explicitly by judges in patent protection cases. The term usually refers to threats made to competitors about a brand-name manufacturer's tactical use of pharmaceutical patents (including over uses, delivery systems and even packaging), not to extension of any particular patent over an active product ingredient. This article focuses in particular on the 'evergreening' potential of so-called 'linkage' provisions, imposed on the regulatory (safety, quality and efficacy) approval systems for generic pharmaceuticals of Canada and Australia, by specific articles in trade agreements with the US. These 'linkage' provisions have also recently appeared in the Korea-US Free Trade Agreement (KORUSFTA). They require such drug regulators to facilitate notification of, or even prevent, any potential patent infringement by a generic pharmaceutical manufacturer. This article explores the regulatory lessons to be learnt from Canada's and Australia's shared experience in terms of minimizing potential adverse impacts of such 'linkage evergreening' provisions on drug costs and thereby potentially on citizen's access to affordable, essential medicines. PMID:17543113

  6. [Bacterial community structure and diversity in soils of different forest ages and types in Bao- tianman forest, Henan Province, China].

    PubMed

    Bai, Xiao-xu; Shi, Rong-ju; You, Ye-ming; Sheng, Hua-fang; Han, Si-qin; Zhang, Ying

    2015-08-01

    To compare the microbial compositions and diversities in soils of different forest ages and types in Baotianman forest, Henan Province, China, genomic DNA of forest soils was extracted for amplifying the 16S rRNA V4 hyper variable region by PCR and sequencing by Illumina MiSeq. The BIPES, UCHIME and QIIME were employed to analyze the soil bacterial community. It was shown that 60 phyla were identified, with Proteobacteria, Acidobacteria, and Verrucomicrobia representing the most dominant lineages and accounting for 29%, 18.5% and 10% of all sequences, respectively. At the genus level, 1209 genera were identified, the most abundant phylotypes were DA101 (6.3%), Acidobacteria-2 (5.9%), Candidatus Solibacter (2.9%) and Candidatus Nitrososphaera (2.6%). Different forest age and type soil samples had unique compositions and specific high and rare genus. Forest type and age both impacted the soil microbial community structure, and the influence of the former was stronger than the latter. The soil microbial diversity of the 80-year-old Quercus aliena forest was the lowest among all age and type forest soil samples. Soil pH, soil nitrogen and organic carbon contents were the most important factors affecting soil bacterial community structure.

  7. Map of distribution of six forest ownership types in the conterminous United States

    Treesearch

    Jaketon H. Hewes; Brett J. Butler; Greg C. Liknes; Mark D. Nelson; Stephanie A. Snyder

    2014-01-01

    This map depicts the spatial distribution of ownership types across forest land in the conterminous United States circa 2009. The distribution is derived, in part, from Forest Inventory and Analysis (FIA) data that are collected at a sample intensity of approximately one plot per 2400 ha across the United States (U.S. Forest Service 2012). Ownership categories were...

  8. Silvicultural systems for the major forest types of the United States

    Treesearch

    Russell M. Burns

    1983-01-01

    The current trend toward the establishment and care of forests for a wide combination of uses requires flexibility in forest culture and a knowledge of the silvicultural choices available to the resource manager. This publication summarizes the silvicultural systems that appear biologically feasible, on the basis of present knowledge, for each of 48 major forest types...

  9. Drone based estimation of actual evapotranspiration over different forest types

    NASA Astrophysics Data System (ADS)

    Marzahn, Philip; Gampe, David; Castro, Saulo; Vega-Araya, Mauricio; Sanchez-Azofeifa, Arturo; Ludwig, Ralf

    2017-04-01

    Actual evapotranspiration (Eta) plays an important role in surface-atmosphere interactions. Traditionally, Eta is measured by means of lysimeters, eddy-covariance systems or fiber optics, providing estimates which are spatially restricted to a footprint from a few square meters up to several hectares . In the past, several methods have been developed to derive Eta by means of multi-spectral remote sensing data using thermal and VIS/NIR satellite imagery of the land surface. As such approaches do have their justification on coarser scales, they do not provide Eta information on the fine resolution plant level over large areas which is mandatory for the detection of water stress or tree mortality. In this study, we present a comparison of a drone based assessment of Eta with eddy-covariance measurements over two different forest types - a deciduous forest in Alberta, Canada and a tropical dry forest in Costa Rica. Drone based estimates of Eta were calculated applying the Triangle-Method proposed by Jiang and Islam (1999). The Triangle-Method estimates actual evapotranspiration (Eta) by means of the Normalized Difference Vegetation Index (NDVI) and land surface temperature (LST) provided by two camera systems (MicaSense RedEdge, FLIR TAU2 640) flown simultaneously on an octocopter. . Results indicate a high transferability of the original approach from Jiang and Islam (1999) developed for coarse to medium resolution satellite imagery tothe high resolution drone data, leading to a deviation in Eta estimates of 10% compared to the eddy-covariance measurements. In addition, the spatial footprint of the eddy-covariance measurement can be detected with this approach, by showing the spatial heterogeneities of Eta due to the spatial distribution of different trees and understory vegetation.

  10. [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

  11. A global assessment of forest surface albedo and its relationships with climate and atmospheric nitrogen deposition.

    PubMed

    Leonardi, Stefano; Magnani, Federico; Nolè, Angelo; Van Noije, Twan; Borghetti, Marco

    2015-01-01

    We present a global assessment of the relationships between the short-wave surface albedo of forests, derived from the MODIS satellite instrument product at 0.5° spatial resolution, with simulated atmospheric nitrogen deposition rates (Ndep ), and climatic variables (mean annual temperature Tm and total annual precipitation P), compiled at the same spatial resolution. The analysis was performed on the following five forest plant functional types (PFTs): evergreen needle-leaf forests (ENF); evergreen broad-leaf forests (EBF); deciduous needle-leaf forests (DNF); deciduous broad-leaf forests (DBF); and mixed-forests (MF). Generalized additive models (GAMs) were applied in the exploratory analysis to assess the functional nature of short-wave surface albedo relations to environmental variables. The analysis showed evident correlations of albedo with environmental predictors when data were pooled across PFTs: Tm and Ndep displayed a positive relationship with forest albedo, while a negative relationship was detected with P. These correlations are primarily due to surface albedo differences between conifer and broad-leaf species, and different species geographical distributions. However, the analysis performed within individual PFTs, strengthened by attempts to select 'pure' pixels in terms of species composition, showed significant correlations with annual precipitation and nitrogen deposition, pointing toward the potential effect of environmental variables on forest surface albedo at the ecosystem level. Overall, our global assessment emphasizes the importance of elucidating the ecological mechanisms that link environmental conditions and forest canopy properties for an improved parameterization of surface albedo in climate models.

  12. Overwintering evergreen oaks reverse typical relationships between leaf traits in a species spectrum

    PubMed Central

    Harayama, Hisanori; Ishida, Atsushi

    2016-01-01

    The leaf economics spectrum has given us a fundamental understanding of the species variations in leaf variables. Across plant species, tight correlations among leaf mass per area (LMA), mass-based nitrogen (Nm) and photosynthetic rate (Am) and leaf lifespan have been well known as trade-offs in leaf carbon economy. However, the regional or biome-level correlations may not be necessary to correspond with the global-scale analysis. Here, we show that almost all leaf variables in overwintering evergreen oaks in Japan were relatively well included within the evergreen-broadleaved trees in worldwide temperate forests, but Nm was more consistent with that in deciduous broadleaved trees. Contrary to the universal correlations, the correlation between Am and Nm among the evergreen oaks was negative and the correlation between Am and LMA disappeared. The unique performance was due to specific nitrogen allocation within leaves, i.e. the evergreen oaks with later leaf maturation had lower Nm but higher nitrogen allocation to photosynthetic enzymes within leaves, to enhance carbon gain against the delayed leaf maturation and the shortened photosynthetic period due to cold winters. Our data demonstrate that correlations between leaf variables in a local scale are occasionally different from averaged global-scale datasets, because of the constraints in each biome. PMID:27493781

  13. Overwintering evergreen oaks reverse typical relationships between leaf traits in a species spectrum.

    PubMed

    Harayama, Hisanori; Ishida, Atsushi; Yoshimura, Jin

    2016-07-01

    The leaf economics spectrum has given us a fundamental understanding of the species variations in leaf variables. Across plant species, tight correlations among leaf mass per area (LMA), mass-based nitrogen (N m) and photosynthetic rate (A m) and leaf lifespan have been well known as trade-offs in leaf carbon economy. However, the regional or biome-level correlations may not be necessary to correspond with the global-scale analysis. Here, we show that almost all leaf variables in overwintering evergreen oaks in Japan were relatively well included within the evergreen-broadleaved trees in worldwide temperate forests, but N m was more consistent with that in deciduous broadleaved trees. Contrary to the universal correlations, the correlation between A m and N m among the evergreen oaks was negative and the correlation between A m and LMA disappeared. The unique performance was due to specific nitrogen allocation within leaves, i.e. the evergreen oaks with later leaf maturation had lower N m but higher nitrogen allocation to photosynthetic enzymes within leaves, to enhance carbon gain against the delayed leaf maturation and the shortened photosynthetic period due to cold winters. Our data demonstrate that correlations between leaf variables in a local scale are occasionally different from averaged global-scale datasets, because of the constraints in each biome.

  14. Forests

    Treesearch

    Louis R. Iverson; Mark W. Schwartz

    1994-01-01

    Originally diminished by development, forests are coming back: forest biomass is accumulating. Forests are repositories for many threatened species. Even with increased standing timber, however, biodiversity is threatened by increased forest fragmentation and by exotic species.

  15. Forest vegetation of the Black Hills National Forest of South Dakota and Wyoming: A habitat type classification

    Treesearch

    George R. Hoffman; Robert R. Alexander

    1987-01-01

    A vegetation classification based on concepts and methods developed by Daubenmire was used to identify 12 forest habitat types and one shrub habitat type in the Black Hills. Included were two habitat types in the Quercus macrocarpa series, seven in the Pinus ponderosa series, one in the Populus tremuloides series, two in the Picea glaucci series, and one in the...

  16. Technical assistance for intensive culture of northern forest types

    Treesearch

    Timothy G. OKeffe

    1977-01-01

    During this Bicentennial celebration, it is interesting to note that in America TA programs in forestry have evolved from both a formal and an informal foundation. European foresters, attempting to motivate many small forest landowners to practice more intensive forest management, have learned that incentive and educational TA programs are far more effective than...

  17. Status of fertilization and nutrition research in northern forest types

    Treesearch

    Miroslaw M. Czapowskyj

    1977-01-01

    Forest fertilization is a useful tool that, when combined with other silvicultural practices, results in increased forest growth. Many experiments have demonstrated that both hardwoods and conifers of the northern forest respond to the addition of one or more nutrients. Examples of pitfalls and successes are given. Present status of research and future research needs...

  18. Precipitation signal in pollen rain from tropical forests, South India.

    PubMed

    Barboni, D; Bonnefille, R

    2001-04-01

    We have analyzed the pollen content of 51 surface soil samples collected in tropical evergreen and deciduous forests from the Western Ghats of South India sampled along a west to east gradient of decreasing rainfall (between 11 degrees 30-13 degrees 20'N and 75 degrees 30-76 degrees 30'E). Values of mean annual precipitation (Pann, mm/yr) have been calculated at each of the 51 sampling sites from a great number of meteorological stations in South India, using a method of data interpolation based on artificial neural network. Interpolated values at the pollen sites of Pann range from 1200 to 5555mm/yr, while mean temperature of the coldest month (MTCO) remains >15 degrees C and humidity factor (AET/PET, the actual evapotranspiration to potential evapotranspiration ratio) remains also included between 65 and 72%.Results are presented in the form of percentage pollen diagrams where samples are arranged according to increasing values of annual precipitation. They indicate that the climatic signal of rainfall is clearly evidenced by distinct pollen associations. Numerical analyses show that annual precipitation is an important parameter explaining the modern distribution of pollen taxa in this region. Pollen taxa markers of high rainfall (Pann >2500mm/yr) are Mallotus type, Elaeocarpus, Syzygium type, Olea dioica, Gnetum ula, and Hopea type, associated with Ixora type and Caryota. Pollen taxa markers of low rainfall (Pann <2500mm/yr) are Melastomataceae/Combretaceae, Maytenus type, Lagerstroemia and Grewia. The proportions of evergreen taxa and of arboreal taxa vary according to rainfall values. Indeed, when rainfall is <2500mm/yr, percentage of arboreal pollen (AP) is <50% and proportion of evergreen taxa is <20%. When rainfall exceeds 2500mm/yr, AP values average 70%, and proportion of evergreen taxa increases from 60 to 90%. Moreover, a good correlation between precipitation and proportion of evergreen taxa (0.85) presumes that precipitation can be estimated from

  19. Forest type affects the influence of harvest on annual and cumulative litter decay in forest and wetland sites across Canada.

    NASA Astrophysics Data System (ADS)

    Trofymow, J. A.; Thompson, E.; Cameron, A.; Pare, D.; Lavigne, M.; Flanagan, L.; Moore, T.; Amiro, B.; Smyth, C.

    2007-12-01

    A litter decomposition study was established in 16 sites at 7 stations of the Fluxnet Canada Research Network. These sites included paired mature and clearcut forest sites at 5 upland stations (BC, SK, ON, QC, NB) as well as one site at each of two wetland stations (AW, QW) . All sites are instrumented for in situ measurements of soil moisture and temperature. Litterbags were prepared using one of four standard material types (aspen leaves - AL, black spruce needles BS, Douglas fir needles DF and birch wood sticks BW). Six replicate plots were located at each site, each plot contained sufficient numbers of surface litterbags of each material type to allow for four annual collections (2004 - 2007). As well unconfined birch chopsticks were placed at three depths down the soil profile (surface, 5cm, 15cm) and replaced annually to examine the effects of interannual variability on decay. Cumulative litter decay after three years litters rank by % mass remaining had ALforests, other than birchwood at one site (QC). Decay of surface birch sticks were similar and interannual variability was less than variability down the soil profile. The effects of clearcut varied with forest site type, on wetter sites surface BW decayed faster in clearcuts than closed forest, however this was reversed in drier forest site types. At lower soil depths on drier sites, decay was more rapid in clearcuts than closed forest. Work is continuing to relate insitu microclimates to decay rates.

  20. Correlation between the morphogenetic types of litter and their properties in bog birch forests

    NASA Astrophysics Data System (ADS)

    Efremova, T. T.; Efremov, S. P.; Avrova, A. F.

    2010-08-01

    A formalized arrangement of morphogenetic types of litter according to the physicochemical parameters provided their significant grouping in three genetic associations. The litter group (highly decomposed + moderately decomposed) is confined to the tall-grass group of bog birch forests. The rhizomatous (roughly decomposed) litter is formed in the sedge-reed grass bog birch forests. The litter group (peaty + peatified + peat) is associated with the bog-herbaceous-moss group of forest types. The genetic associations of the litters (a) reliably characterize the edaphic conditions of bog birch forests and (b)correspond to formation of the peat of certain ecological groups. We found highly informative the acid-base parameters, the exchangeable cations (Ca2+ + Mg2+) and the total potential acidity, which differentiated the genetic associations of litter practically with 100% probability. The expediency of studying litters under groups of forest types rather than under separate types of bog birch forests was demonstrated.

  1. A gap-filling model for eddy covariance CO2 flux: Estimating carbon assimilated by a subtropical evergreen broad-leaved forest at the Lien-Hua-Chih flux observation site

    NASA Astrophysics Data System (ADS)

    Lan, C. Y.; Li, M. H.; Chen, Y. Y.

    2016-12-01

    Appropriate estimations of gaps appeared in eddy covariance (EC) flux observations are critical to the reliability of long-term EC applications. In this study we present a semi-parametric multivariate gap-filling model for tower-based measurement of CO2 flux. The raw EC data passing QC/QA was separated into two groups, clear sky, having net radiation greater than 50 W/m2, and nighttime/cloudy. For the clear sky conditions, the principle component analysis (PCA) was used to resolve the multicollinearity relationships among various environmental variables, including net radiation, wind speed, vapor pressure deficit, soil moisture deficit, leaf area index, and soil temperature, in association with CO2 assimilated by forest. After the principal domains were determined by the PCA, the relationships between CO2 fluxes and selected PCs (key factors) were built up by nonlinear interpolations to estimate the gap-filled CO2 flux. In view of limited photosynthesis at nighttime/cloudy conditions, respiration rate of the forest ecosystem was estimated by the Lloyd-Tylor equation. Artificial gaps were randomly selected to exam the applicability of our PCA approach. Based on tower-based measurement of CO2 flux at the Lien-Hua-Chih site, a total of 5.8 ton-C/ha/yr was assimilated in 2012.

  2. Spatial and seasonal variations of leaf area index (LAI) in subtropical secondary forests related to floristic composition and stand characters

    NASA Astrophysics Data System (ADS)

    Zhu, Wenjuan; Xiang, Wenhua; Pan, Qiong; Zeng, Yelin; Ouyang, Shuai; Lei, Pifeng; Deng, Xiangwen; Fang, Xi; Peng, Changhui

    2016-07-01

    Leaf area index (LAI) is an important parameter related to carbon, water, and energy exchange between canopy and atmosphere and is widely applied in process models that simulate production and hydrological cycles in forest ecosystems. However, fine-scale spatial heterogeneity of LAI and its controlling factors have yet to be fully understood in Chinese subtropical forests. We used hemispherical photography to measure LAI values in three subtropical forests (Pinus massoniana-Lithocarpus glaber coniferous and evergreen broadleaved mixed forests, Choerospondias axillaris deciduous broadleaved forests, and L. glaber-Cyclobalanopsis glauca evergreen broadleaved forests) from April 2014 to January 2015. Spatial heterogeneity of LAI and its controlling factors were analysed using geostatistical methods and the generalised additive models (GAMs) respectively. Our results showed that LAI values differed greatly in the three forests and their seasonal variations were consistent with plant phenology. LAI values exhibited strong spatial autocorrelation for the three forests measured in January and for the L. glaber-C. glauca forest in April, July, and October. Obvious patch distribution pattern of LAI values occurred in three forests during the non-growing period and this pattern gradually dwindled in the growing season. Stem number, crown coverage, proportion of evergreen conifer species on basal area basis, proportion of deciduous species on basal area basis, and forest types affected the spatial variations in LAI values in January, while stem number and proportion of deciduous species on basal area basis affected the spatial variations in LAI values in July. Floristic composition, spatial heterogeneity, and seasonal variations should be considered for sampling strategy in indirect LAI measurement and application of LAI to simulate functional processes in subtropical forests.

  3. Analysis and Evaluation of Project EVERGREEN Data

    DTIC Science & Technology

    1991-09-01

    Anton , Howard and Rorres, Chris, Elementary Linear Algebra with AyDlications, John Wiley and Sons, New York, 1987. 2. Binnall, Eugene P., EVERGREEN...2. Transmitter used was a Febetron. 3. Elevation angle ( Source ) = 45 degrees. 4. Polarization transmitted - Linear "Horizontal". 5. Polarization...2. Transmitter used was a Febetron. 3. Elevation angle ( Source ) = 45 degrees. 4. Polarization transmitted - Linear "Horizontal". 5. Polarization

  4. Information about old growth for selected forest type groups in the eastern United States.

    Treesearch

    Lucy E. Tyrrell; Gregory J. Nowacki; David S. Buckley; Elizabeth A. Nauertz; Jeffrey N. Niese; Jeanette L. Rollinger; John C. Zasada; John C. Zasada

    1998-01-01

    Compiles information about old-growth attributes for nine forest type groups that occur in the eastern United States. A range of values for each old-growth attribute for each forest type is summarized regionally from published and unpublished sources.

  5. Small mammal habitat associations in poletimber and sawtimber stands of four forest cover types

    Treesearch

    Richard M. DeGraaf; Dana P. Snyder; Barbara J. Hill

    1991-01-01

    Small mammal distribution was examined in poletimber and sawtimber stands of four forest cover types in northern New England: northern hardwoods, red maple, balsam fir, and red spruce-balsam fir. During 1980 and 1981, eight stands on the White Mountain National Forest, NH, were sampled with four trap types (three sizes of snap traps and one pit-fall) for 16 000 trap-...

  6. Logging residues in principal forest types of the Northern Rocky Mountains

    Treesearch

    Robert E. Benson; Joyce A. Schlieter

    1980-01-01

    An estimated 466 million ft 3 of forest residue material (nonmerchantable, 3 inches diameter and larger) is generated annually in the Northern Rocky Mountains (Montana, Idaho, Wyoming). Extensive studies of residues in the major forest types show a considerable portion is suited for various products. The lodgepole pine type has the greatest potential for increased...

  7. Stereo photo series for quantifying forest residues in the Douglas-Fir-Hemlock type of the Willamette National Forest.

    Treesearch

    Roger D. Ottmar; Colin C. Hardy; Robert E. Vihnanek

    1990-01-01

    A series of stereo photographs displays a range of residue loadings for harvested units in the Douglas-fir-western hemlock cover type common to the Willamette National Forest. Postburn residue levels are also represented for the Douglas-fir-western hemlock types. Information with each photo includes measured quadratic means and weights for various size classes, woody...

  8. Impact of cloudiness on net ecosystem exchange of carbon dioxide in different types of forest ecosystems in China

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Yu, G.-R.; Zhang, L.-M.; Sun, X.-M.; Wen, X.-F.; Han, S.-J.; Yan, J.-H.

    2009-08-01

    Clouds can significantly affect carbon uptake of forest ecosystems by affecting incoming solar radiation on the ground, temperature and other environmental factors. In this study, we analyzed the effects of cloudiness on the net ecosystem exchange of carbon dioxide (NEE) of a temperate broad-leaved Korean pine mixed forest at Changbaishan (CBS) and a subtropical evergreen broad-leaved forest at Dinghushan (DHS) of ChinaFLUX, based on the flux data obtained during June-August from 2003 to 2006. The results showed that the response of the NEE of forest ecosystem to photosynthetically active radiation (PAR) was different under clear sky and cloudy sky conditions, and this difference was not consistent between CBS and DHS. Compared with clear skies, light-saturated maximum photosynthetic rate (Pec,max) of CBS during mid-growing season (from June to August) was respectively enhanced by 34%, 25%, 4% and 11% on cloudy skies in 2003, 2004, 2005 and 2006; however, Pec,max of DHS was higher under clear skies than under cloudy skies from 2004 to 2006. NEE of forests at CBS reached its maximum when the clearness index (kt) was between 0.4 and 0.6, and the NEE decreased obviously when kt exceeded 0.6. Compare with CBS, although NEE of forest at DHS tended to the maximum when kt varied between 0.4 and 0.6, the NEE did not decrease noticeably when kt exceeded 0.6. The results indicated that cloudy sky conditions were more beneficial to carbon uptake for the temperate forest ecosystem rather than for the subtropical forest ecosystem. This is due to the fact that the non-saturating light conditions and increase of diffuse radiation were more beneficial to photosynthesis, and the reduced temperature was more conducive to decreasing the ecosystem respiration in temperate forest ecosystems under cloudy sky conditions. This phenomenon is important to evaluate carbon uptake of temperate forests under climate change conditions.

  9. Impact of cloudiness on net ecosystem exchange of carbon dioxide in different types of forest ecosystems in China

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Yu, G.-R.; Zhang, L.-M.; Sun, X.-M.; Wen, X.-F.; Han, S.-J.; Yan, J.-H.

    2010-02-01

    Clouds can significantly affect carbon exchange process between forest ecosystems and the atmosphere by influencing the quantity and quality of solar radiation received by ecosystem's surface and other environmental factors. In this study, we analyzed the effects of cloudiness on net ecosystem exchange of carbon dioxide (NEE) in a temperate broad-leaved Korean pine mixed forest at Changbaishan (CBS) and a subtropical evergreen broad-leaved forest at Dinghushan (DHS), based on the flux data obtained during June-August from 2003 to 2006. The results showed that the response of NEE of forest ecosystems to photosynthetically active radiation (PAR) differed under clear skies and cloudy skies. Compared with clear skies, the light-saturated maximum photosynthetic rate (Pec,max) at CBS under cloudy skies during mid-growing season (from June to August) increased by 34%, 25%, 4% and 11% in 2003, 2004, 2005 and 2006, respectively. In contrast, Pec,max of the forest ecosystem at DHS was higher under clear skies than under cloudy skies from 2004 to 2006. When the clearness index (kt) ranged between 0.4 and 0.6, the NEE reached its maximum at both CBS and DHS. However, the NEE decreased more dramatically at CBS than at DHS when kt exceeded 0.6. The results indicate that cloudy sky conditions are beneficial to net carbon uptake in the temperate forest ecosystem and the subtropical forest ecosystem. Under clear skies, vapor pressure deficit (VPD) and air temperature increased due to strong light. These environmental conditions led to greater decrease in gross ecosystem photosynthesis (GEP) and greater increase in ecosystem respiration (Re) at CBS than at DHS. As a result, clear sky conditions caused more reduction of NEE in the temperate forest ecosystem than in the subtropical forest ecosystem. The response of NEE of different forest ecosystems to the changes in cloudiness is an important factor that should be included in evaluating regional carbon budgets under climate change

  10. Landsat for practical forest type mapping - A test case

    NASA Technical Reports Server (NTRS)

    Bryant, E.; Dodge, A. G., Jr.; Warren, S. D.

    1980-01-01

    Computer classified Landsat maps are compared with a recent conventional inventory of forest lands in northern Maine. Over the 196,000 hectare area mapped, estimates of the areas of softwood, mixed wood and hardwood forest obtained by a supervised classification of the Landsat data and a standard inventory based on aerial photointerpretation, probability proportional to prediction, field sampling and a standard forest measurement program are found to agree to within 5%. The cost of the Landsat maps is estimated to be $0.065/hectare. It is concluded that satellite techniques are worth developing for forest inventories, although they are not yet refined enough to be incorporated into current practical inventories.

  11. Similar variation in carbon storage between deciduous and evergreen treeline species across elevational gradients

    PubMed Central

    Fajardo, Alex; Piper, Frida I.; Hoch, Günter

    2013-01-01

    Background and Aims The most plausible explanation for treeline formation so far is provided by the growth limitation hypothesis (GLH), which proposes that carbon sinks are more restricted by low temperatures than by carbon sources. Evidence supporting the GLH has been strong in evergreen, but less and weaker in deciduous treeline species. Here a test is made of the GLH in deciduous–evergreen mixed species forests across elevational gradients, with the hypothesis that deciduous treeline species show a different carbon storage trend from that shown by evergreen species across elevations. Methods Tree growth and concentrations of non-structural carbohydrates (NSCs) in foliage, branch sapwood and stem sapwood tissues were measured at four elevations in six deciduous–evergreen treeline ecotones (including treeline) in the southern Andes of Chile (40°S, Nothofagus pumilio and Nothofagus betuloides; 46°S, Nothofagus pumilio and Pinus sylvestris) and in the Swiss Alps (46°N, Larix decidua and Pinus cembra). Key Results Tree growth (basal area increment) decreased with elevation for all species. Regardless of foliar habit, NSCs did not deplete across elevations, indicating no shortage of carbon storage in any of the investigated tissues. Rather, NSCs increased significantly with elevation in leaves (P < 0·001) and branch sapwood (P = 0·012) tissues. Deciduous species showed significantly higher NSCs than evergreens for all tissues; on average, the former had 11 % (leaves), 158 % (branch) and 103 % (sapwood) significantly (P < 0·001) higher NSCs than the latter. Finally, deciduous species had higher NSC (particularly starch) increases with elevation than evergreens for stem sapwood, but the opposite was true for leaves and branch sapwood. Conclusions Considering the observed decrease in tree growth and increase in NSCs with elevation, it is concluded that both deciduous and evergreen treeline species are sink limited when faced with decreasing temperatures

  12. [Estimation for vegetation carbon storage in Tiantong National Forest Park].

    PubMed

    Guo, Chun-Zi; Wu, Yang-Yang; Ni, Jian

    2014-11-01

    Based on the field investigation and the data combination from literature, vegetation carbon storage, carbon density, and their spatial distribution were examined across six forest community types (Schima superba--Castanopsis fargesii community, S. superba--C. fargesii with C. sclerophylla community, S. superba--C. fargesii with Distylium myricoides community, Illicium lanceolatum--Choerospondias axillaris community, Liquidambar formosana--Pinus massoniana community and Hedyotis auricularia--Phylostachys pubescens community) in Tiantong National Forest Park, Zhejiang Province, by using the allometric biomass models for trees and shrubs. Results showed that: Among the six communities investigated, carbon storage and carbon density were highest in the S. superba--C. fargesii with C. sclerophylla community (storage: 12113.92 Mg C; density: 165.03 Mg C · hm(-2)), but lowest in the I. lanceolatum--C. axillaris community (storage: 680.95 Mg C; density: 101.26 Mg C · hm(-2)). Carbon storage was significantly higher in evergreen trees than in deciduous trees across six communities. Carbon density ranged from 76.08 to 144.95 Mg C · hm(-2), and from 0. 16 to 20. 62 Mg C · hm(-2) for evergreen trees and deciduous trees, respectively. Carbon storage was highest in stems among tree tissues in the tree layer throughout communities. Among vegetation types, evergreen broad-leaved forest had the highest carbon storage (23092.39 Mg C), accounting for 81.7% of the total carbon storage in all forest types, with a car- bon density of 126.17 Mg C · hm(-2). Total carbon storage for all vegetation types in Tiantong National Forest Park was 28254.22 Mg C, and the carbon density was 96.73 Mg C · hm(-2).

  13. Stable carbon isotope labeling reveals different carry-over effects between functional types of tropical trees in an Ethiopian mountain forest.

    PubMed

    Krepkowski, Julia; Gebrekirstos, Aster; Shibistova, Olga; Bräuning, Achim

    2013-07-01

    We present an intra-annual stable carbon isotope (δ(13)C) study based on a labeling experiment to illustrate differences in temporal patterns of recent carbon allocation to wood structures of two functional types of trees, Podocarpus falcatus (a late-successional evergreen conifer) and Croton macrostachyus (a deciduous broadleaved pioneer tree), in a tropical mountain forest in Ethiopia. Dendrometer data, wood anatomical thin sections, and intra-annual δ(13)C analyses were applied. Isotope data revealed a clear annual growth pattern in both studied species. For P. falcatus, it was possible to synchronize annual δ(13) C peaks, wood anatomical structures and monthly precipitation patterns. The labeling signature was evident for three consecutive years. For C. macrostachyus, isotope data illustrate a rapid decline of the labeling signal within half a year. Our δ(13)C labeling study indicates a distinct difference in carryover effects between trees of different functional types. A proportion of the labeled δ(13)C is stored in reserves of wood parenchyma for up to 3 yr in P. falcatus. By contrast, C. macrostachyus shows a high turnover of assimilates and a carbon carryover effect is only detectable in the subsequent year.

  14. Mapping diverse forest cover with multipolarization airborne radar

    NASA Technical Reports Server (NTRS)

    Ford, J. P.; Wickland, D. E.; Sharitz, R. R.

    1985-01-01

    Imaging radar backscatter in continuously forested areas contains information about the forest canopy; it also contains data about topography, landforms, and terrain texture. For purposes of radar image interpretation and geologic mapping researchers were interested in identifying and separating forest canopy effects from geologic or geomorphic effects on radar images. The objectives of this investigation was to evaluate forest canopy variables in multipolarization radar images under conditions where geologic and topographic variables are at a minimum. A subsidiary objective was to compare the discriminatory capabilities of the radar images with corresponding optical images of similar spatial resolution. It appears that the multipolarization images discriminate variation in tree density, but no evidence was found for discrimination between evergreen and deciduous forest types.

  15. Terrestrial activity, abundance, diversity of amphibians in differently managed forest types

    SciTech Connect

    Bennett, S.H.; Gibbons, J.W.; Glanville, J.

    1980-04-01

    Diversity indices and relative abundances were determined for amphibians inhabiting three differently managed forest types in South Carolina. Study sites were contiguous around a small lake, and included a slash pine (Pinus ellioti) forest, a loblolly pine (Pinus taeda) forest and a hardwood (predominately oak-hickory) forest. Amphibians were collected using a drift fence and pitfall trap method. Captured animals were marked so that recaptures could be removed from calculations of indices. The dates of study were 30 June-10 August 1977 and 20 June-15 August 1978. The three study sites were similar in species diversity and the evenness component for combined summer data and for the summer of 1978. The hardwood forest had a higher diversity in the summer of 1977. The hardwood forest yielded approximately 50% more individual amphibians than either pine forest during both years.

  16. Regional estimation of current and future forest biomass.

    PubMed

    Mickler, R A; Earnhardt, T S; Moore, J A

    2002-01-01

    The 90,674 wildland fires that burned 2.9 million ha at an estimated suppression cost of $1.6 billion in the United States during the 2000 fire season demonstrated that forest fuel loading has become a hazard to life, property, and ecosystem health as a result of past fire exclusion policies and practices. The fire regime at any given location in these regions is a result of complex interactions between forest biomass, topography, ignitions, and weather. Forest structure and biomass are important aspects in determining current and future fire regimes. Efforts to quantify live and dead forest biomass at the local to regional scale has been hindered by the uncertainty surrounding the measurement and modeling of forest ecosystem processes and fluxes. The interaction of elevated CO2 with climate, soil nutrients, and other forest management factors that affect forest growth and fuel loading will play a major role in determining future forest stand growth and the distribution of species across the southern United States. The use of satellite image analysis has been tested for timely and accurate measurement of spatially explicit land use change and is well suited for use in inventory and monitoring of forest carbon. The incorporation of Landsat Thematic Mapper data coupled with a physiologically based productivity model (PnET), soil water holding capacity, and historic and projected climatic data provides an opportunity to enhance field plot based forest inventory and monitoring methodologies. We use periodic forest inventory data from the USDA Forest Service's Forest Inventory and Analysis (FIA) project to obtain estimates of forest area and type to generate estimates of carbon storage for evergreen, deciduous, and mixed forest classes for use in an assessment of remotely sensed forest cover at the regional scale for the southern United States. The displays of net primary productivity (NPP) generated from the PnET model show areas of high and low forest carbon storage

  17. Differential controls on soil carbon density and mineralization among contrasting forest types in a temperate forest ecosystem

    PubMed Central

    You, Ye-Ming; Wang, Juan; Sun, Xiao-Lu; Tang, Zuo-Xin; Zhou, Zhi-Yong; Sun, Osbert Jianxin

    2016-01-01

    Understanding the controls on soil carbon dynamics is crucial for modeling responses of ecosystem carbon balance to global change, yet few studies provide explicit knowledge on the direct and indirect effects of forest stands on soil carbon via microbial processes. We investigated tree species, soil, and site factors in relation to soil carbon density and mineralization in a temperate forest of central China. We found that soil microbial biomass and community structure, extracellular enzyme activities, and most of the site factors studied varied significantly across contrasting forest types, and that the associations between activities of soil extracellular enzymes and microbial community structure appeared to be weak and inconsistent across forest types, implicating complex mechanisms in the microbial regulation of soil carbon metabolism in relation to tree species. Overall, variations in soil carbon density and mineralization are predominantly accounted for by shared effects of tree species, soil, microclimate, and microbial traits rather than the individual effects of the four categories of factors. Our findings point to differential controls on soil carbon density and mineralization among contrasting forest types and highlight the challenge to incorporate microbial processes for constraining soil carbon dynamics in global carbon cycle models. PMID:26925871

  18. Regionalisation of climate change sensitive forest development types for potential afforestation areas.

    PubMed

    Witt, Anke; Fürst, Christine; Frank, Susanne; Koschke, Lars; Makeschin, Franz

    2013-09-01

    This paper describes how to use sectoral planning information from forestry to predict and up-scale information on Climate Change sensitive forest development types for potential afforestation areas. The method was developed and applied in the frame of the project RegioPower with focus on the case study region 'Oberes Elbtal-Osterzgebirge'. The data for our study was taken from forest management planning at level of the Federal State of Saxony, Germany. Here, a silvicultural system is implemented, which describes best practices to develop our actual forests into Climate Change adapted forest development types. That includes the selection of drought resistant tree species, a broad range of tree species mixtures per eligible forest development type and the tending, harvesting and regeneration strategies to be applied. This information however, exists only for forest areas and not for areas which could be potentially afforested. The eligibility of the forest development types within the actual forest areas depends on site information, such as nutrient potential, exposition and hydrological soil parameters. The regionalisation of the forest development types to landscape scale had to be based on topographical parameters from the digital elevation model and hydrological soil parameters from soil mapping. In result, we could provide maps for regional planning and decision making with spatially explicit information on the eligible forest development types based on forest management planning information. These maps form a valuable input for testing and optimising afforestation areas with regard to improving the ability of our case study region to mitigate Climate Change effects such as water erosion or drought.

  19. Canopy structure on forest lands in western Oregon: differences among forest types and stand ages

    Treesearch

    Anne C.S. McIntosh; Andrew N. Gray; Steven L. Garman

    2009-01-01

    Canopy structure is an important attribute affecting economic and ecological values of forests in the Pacific Northwest. However, canopy cover and vertical layering are rarely measured directly; they are usually inferred from other forest measurements. In this study, we quantified and compared vertical and horizontal patterns of tree canopy structure and understory...

  20. Changes to the N cycle following bark beetle outbreaks in two contrasting conifer forest types.

    PubMed

    Griffin, Jacob M; Turner, Monica G

    2012-10-01

    Outbreaks of Dendroctonus beetles are causing extensive mortality in conifer forests throughout North America. However, nitrogen (N) cycling impacts among forest types are not well known. We quantified beetle-induced changes in forest structure, soil temperature, and N cycling in Douglas-fir (Pseudotsuga menziesii) forests of Greater Yellowstone (WY, USA), and compared them to published lodgepole pine (Pinus contorta var. latifolia) data. Five undisturbed stands were compared to five beetle-killed stands (4-5 years post-outbreak). We hypothesized greater N cycling responses in Douglas-fir due to higher overall N stocks. Undisturbed Douglas-fir stands had greater litter N pools, soil N, and net N mineralization than lodgepole pine. Several responses to disturbance were similar between forest types, including a pulse of N-enriched litter, doubling of soil N availability, 30-50 % increase in understory cover, and 20 % increase in foliar N concentration of unattacked trees. However, the response of some ecosystem properties notably varied by host forest type. Soil temperature was unaffected in Douglas-fir, but lowered in lodgepole pine. Fresh foliar %N was uncorrelated with net N mineralization in Douglas-fir, but positively correlated in lodgepole pine. Though soil ammonium and nitrate, net N mineralization, and net nitrification all doubled, they remained low in both forest types (<6 μg N g soil(-1) NH(4) (+)or NO(3) (-); <25 μg N g soil(-1) year(-1) net N mineralization; <8 μg N g soil(-1) year(-1) net nitrification). Results suggest that beetle disturbance affected litter and soil N cycling similarly in each forest type, despite substantial differences in pre-disturbance biogeochemistry. In contrast, soil temperature and soil N-foliar N linkages differed between host forest types. This result suggests that disturbance type may be a better predictor of litter and soil N responses than forest type due to similar disturbance mechanisms and disturbance legacies

  1. Intermediate inclinations of type 2 Coronal-Line Forest AGN

    NASA Astrophysics Data System (ADS)

    Rose, Marvin; Elvis, Martin; Crenshaw, Michael; Glidden, Ana

    2015-07-01

    Coronal-Line Forest Active Galactic Nuclei (CLiF AGN) are remarkable in the sense that they have a rich spectrum of dozens of coronal emission lines (e.g. [Fe VII], [Fe X] and [Ne V]) in their spectra. Rose, Elvis & Tadhunter suggest that the inner obscuring torus wall is the most likely location of the coronal line region in CLiF AGN, and the unusual strength of the forbidden high-ionization lines is due to a specific AGN-torus inclination angle. Here, we test this suggestion using mid-IR colours (4.6-22 μm) from the Wide-Field Infrared Survey Explorer for the CLiF AGN. We use the Fischer et al. result that showed that as the AGN-torus inclination becomes more face on, the Spitzer 5.5-30 μm colours become bluer. We show that the [W2-W4] colours for the CLiF AGN (<[W2-W4]> = 5.92 ± 0.12) are intermediate between Sloan Digital Sky Survey (SDSS) type 1 (<[W2-W4]> = 5.22 ± 0.01) and type 2 AGN (<[W2-W4]> = 6.35 ± 0.03). This implies that the AGN-torus inclinations for the CLiF AGN are indeed intermediate, supporting the work of Rose, Elvis & Tadhunter. The confirmed relation between CLiF AGN and their viewing angle shows that CLiF AGN may be useful for our understanding of AGN unification.

  2. Quantifying tropical dry forest type and succession: substantial improvement with LiDAR

    Treesearch

    Sebastian Martinuzzi; William A. Gould; Lee A. Vierling; Andrew T. Hudak; Ross F. Nelson; Jeffrey S. Evans

    2012-01-01

    Improved technologies are needed to advance our knowledge of the biophysical and human factors influencing tropical dry forests, one of the world’s most threatened ecosystems. We evaluated the use of light detection and ranging (LiDAR) data to address two major needs in remote sensing of tropical dry forests, i.e., classification of forest types and delineation of...

  3. Amphibian and reptile abundance in riparian and upslope areas of five forest types in western Oregon

    USGS Publications Warehouse

    Gomez, D.M.; Anthony, R.G.

    1996-01-01

    We compared species composition and relative abundance of herpetofauna between riparian and upslope habitats among 5 forest types (shrub, open sapling-pole, large sawtimber and old-growth conifer forests, and deciduous forests) in Western Oregon. Riparian- and upslope- associated species were identified based on capture frequencies from pitfall trapping. Species richness was similar among forest types but slightly greater in the shrub stands. The abundances of 3 species differed among forest types. Total captures was highest in deciduous forests, intermediate in the mature conifer forests, and lowest in the 2 young coniferous forests. Species richness was similar between stream and upslope habitats; however, captures were higher in riparian than upslope habitat. Tailed frogs (Ascaphus truei), Dunn's salamanders (Plethodon dunni), roughskin newts(Tanicha granulosa), Pacific giant salamanders (Dicamptodon tenebrosus) and red-legged frogs(Rana aurora) were captured more frequently in riparian than upslope habitats. Of these species the red-legged frog and Pacific giant salamander may depend on riparian habitat for at least part of their life requirements, while tailed frogs, Dunn's salamanders and roughskin newts appear to be riparian associated species. In addition, we found Oregon salamanders (Ensatina eschscholtzi) were associated with upslope habitats. We suggest riparian management zones should be al least 75-100 m on each side of the stream and that management for upslope/and or old forest associates may be equally as important as for riparian species.

  4. 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.

  5. 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

  6. Forest biomass estimation with hemispherical photography for multiple forest types and various atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Clark, Joshua Andrew

    The importance of accurately identifying inventories of domestic energy, including forest biomass, has increasingly become a priority of the US government and its citizens as the cost of fossil fuels has risen. It is useful to identify which of these resources can be processed and transported at the lowest cost for both private and public landowners. Accurate spatial inventories of forest biomass can help landowners allocate resources to maximize forest biomass utilization and provide information regarding current forest health (e.g., forest fire potential, insect susceptibility, wildlife habitat range). This research has indicated that hemispherical photography (HP) may be an accurate and low cost sensing technique for forest biomass measurements. In this dissertation: (1) It is shown that HP gap fraction measurements and both above ground biomass and crown biomass have a linear relationship. (2) It is demonstrated that careful manipulation of images improves gap fraction estimates, even under unfavorable atmospheric conditions. (3) It is shown that estimates of Leaf Area Index (LAI), based on transformations of gap fraction measurements, are the best estimator for both above ground forest biomass and crown biomass. (4) It is shown that many factors negatively influence the utility of HP for biomass estimation. (5) It is shown that biomass of forests stands with regular spacing is not modeled well using HP. As researchers continue to explore different methods for forest biomass estimation, HP is likely to remain as a viable technique, especially if LAI can be accurately estimated. However, other methods should be compared with HP, particularly for stands where LAI is poorly estimated by HP.

  7. 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-...

  8. Site factor variations and responses in temporary forest types in northern Idaho

    Treesearch

    J. A. Larsen

    1940-01-01

    The object of the study was to analyze and evaluate the environmental factors which govern the progressional stages of the secondary forest succession in northern Idaho. \\When this study began much uncertainty existed regarding the distribution of trees and forest types in relation to temperature, precipitation, and evaporation and regarding their soil moisture and...

  9. The Forest Types and Ages Cleared for Land Development in Puerto Rico.

    Treesearch

    Todd Kennaway; E. H. Helmer

    2007-01-01

    On the Caribbean island of Puerto Rico, forest, urban/built-up, and pasture lands have replaced most formerly cultivated lands. The extent and age distribution of each forest type that undergoes land development, however, is unknown. This study assembles a time series of four land cover maps for Puerto Rico. The time series includes two digitized paper maps of land...

  10. Regional forest fragmentation effects on bottomland hardwood community types and resource values

    Treesearch

    Victor A. Rudis

    1995-01-01

    In human-dominated regions, forest vegetation removal impacts remaining ecosystems but regional-scale biological consequences and resource value changes are not well known. Using forest resource survey data, I examined current bottomland hardwood community types and a range of fragment size classes in the south central United States. Analyses examined resource value...

  11. Assessing species variation within forest cover types delineated using color-infrared aerial photographs

    Treesearch

    Clarence E. Neese; Linda S. Gribko

    1997-01-01

    Color-infrared aerial photographs are widely used to aid in the classification and inventory of large forested tracts. Areas of similar photographic color and texture are delineated and a limited number of categories (or groups of areas with similar features) are identified. The forest cover type, and sometimes the average timber volume, of each group is then...

  12. Major forest types and the evolution of sustainable forestry in China.

    PubMed

    Dai, Limin; Wang, Yue; Su, Dongkai; Zhou, Li; Yu, Dapao; Lewis, Bernard J; Qi, Lin

    2011-12-01

    In this article, we introduce China's major forest types and discuss the historical development of forest management in China, including actions taken over the last decade toward achieving SMF. Major challenges are identified, and a strategy for SFM implementation in China is presented. China's forests consist of a wide variety of types with distinctive distributional patterns shaped by complex topography and multiple climate regimes. How to manage this wide array of forest resources has challenged forest managers and policy-makers since the founding of the country. Excessive exploitation of China's forest resources from the 1950s to the late 1990s contributed to environmental problems and calamities, such as floods, soil erosion, and desertification. At the start of the new millennium, the Chinese government decided to shift its emphasis from timber production towards the achievement of sustainable forest management (SFM). With a series of endeavors such as the implementation of the "Six Key Forestry Projects" and the reform of forest tenure policies, and the adoption of a classification system for China's forests, a beginning has been made at reversing the trend of environmental degradation that occurred throughout the latter half of the last century. At the same time, huge challenges remain to be tackled for the development of forestry in China.

  13. Wildlife species composition in various forest types on Sebuku Island, South Kalimantan

    NASA Astrophysics Data System (ADS)

    Kusmana, C.; Manshur, A.; Rusdian, O.; Putro, H. R.; Hakim, F.; Ermyanyla, M.

    2017-01-01

    Sebuku is one of the small islands in South Kalimantan Provincehaving various forest types with high potential economic in mining sector. Based on it’s business permit, the island has been divided up into several mining concessions. So that biological diversity studies in this island is an interesting in order to serve biological baseline data if someday this island to be extractedfor mining. This research was conducted on 28th November to 5th December 2015 aims to explore wildlife species inhabit mangrove forest, beach forest, and lowland forest usinga rectangle transect (40 x 1000 meter) in each forest type. The results show there are 90 wildlife species identified in Sebuku Island. The beach forest has the highest wildlife species richness (36 species), while the area having the highest protected wildlife species isthe lowland forest. Mangrove forests generally have a lower wildlife species richness. Nevertheless, in Sebuku Island, can be found mangrove forest that have a quite high wildlife species richness (28 species, 50% protected). It is due to silt sedimentation in the estuary area, so that this area become feeding ground for shore and migratory birds.

  14. Winter leaf reddening in 'evergreen' species.

    PubMed

    Hughes, Nicole M

    2011-05-01

    Leaf reddening during autumn in senescing, deciduous tree species has received widespread attention from the public and in the scientific literature, whereas leaf reddening in evergreen species during winter remains largely ignored. Winter reddening can be observed in evergreen herbs, shrubs, vines and trees in Mediterranean, temperate, alpine, and arctic regions, and can persist for several months before dissipating with springtime warming. Yet, little is known about the functional significance of this colour change, or why it occurs in some species but not others. Here, the biochemistry, physiology and ecology associated with winter leaf reddening are reviewed, with special focus on its possible adaptive function. Photoprotection is currently the favoured hypothesis for winter reddening, but alternative explanations have scarcely been explored. Intraspecific reddening generally increases with sunlight incidence, and may also accompany photosynthetic inferiority in photosynthetically 'weak' (e.g. low-nitrogen) individuals. Red leaves tend to show symptoms of shade acclimation relative to green, consistent with a photoprotective function. However, winter-red and winter-green species often cohabitate the same high-light environments, and exhibit similar photosynthetic capacities. The factors dictating interspecific winter leaf colouration therefore remain unclear. Additional outstanding questions and future directions are also highlighted, and possible alternative functions of winter reddening discussed.

  15. Chinese Localisation of Evergreen: An Open Source Integrated Library System

    ERIC Educational Resources Information Center

    Zou, Qing; Liu, Guoying

    2009-01-01

    Purpose: The purpose of this paper is to investigate various issues related to Chinese language localisation in Evergreen, an open source integrated library system (ILS). Design/methodology/approach: A Simplified Chinese version of Evergreen was implemented and tested and various issues such as encoding, indexing, searching, and sorting…

  16. Chinese Localisation of Evergreen: An Open Source Integrated Library System

    ERIC Educational Resources Information Center

    Zou, Qing; Liu, Guoying

    2009-01-01

    Purpose: The purpose of this paper is to investigate various issues related to Chinese language localisation in Evergreen, an open source integrated library system (ILS). Design/methodology/approach: A Simplified Chinese version of Evergreen was implemented and tested and various issues such as encoding, indexing, searching, and sorting…

  17. Differences between forest type and vertical strata in the diversity and composition of hymenopteran families and mymarid genera in northeastern temperate forests.

    PubMed

    Vance, C C; Smith, S M; Malcolm, J R; Huber, J; Bellocq, M I

    2007-10-01

    Most insects' assemblages differ with forest type and show vertical stratification. We tested for differences in richness, abundance and composition of hymenopteran families and mymarid genera between sugar maple (Acer saccharum) and white pine (Pinus strobus) stands and between canopy and understory in northeastern temperate forests in Canada. We used flight interception traps (modified malaise traps) suspended in the canopy and the understory in a split-split block design, with forest type as the main factor, forest stratum as the first split factor, and collection bottle location as the second split factor. Hymenopteran families and mymarid genera differed in their diversity depending on forest type and stratum. Both family and genera richness were higher in maple than in pine forests, whereas family richness was higher in the canopy and top bottles and generic richness was higher in the understory and bottom bottles. Multivariate analysis separated samples by forest type, vegetation stratum, and bottle location. Family composition showed 77% similarity between forest types and 73% between the canopy and understory. At the lower taxa level, mymarid genera showed only 47% similarity between forest types and 40% between forest strata, indicating vertical stratification and relatively high beta-diversity. Our study suggests that hymenopteran diversity and composition is strongly dependent on forest type and structure, making flying members of this order particularly vulnerable to forest management practices. It also shows that insect assemblage composition (especially at low-taxon levels), rather than relative abundance and richness, is the community attribute most sensitive to forest type and vertical stratification.

  18. Climate Extremes and Forest Carbon Sequestration Capacities

    NASA Astrophysics Data System (ADS)

    Wei, S.; Yi, C.; Hendrey, G. R.; Eaton, T. T.; Liu, H.; Rustic, G. T.; Krakauer, N.; Wang, S.

    2013-12-01

    Several lines of evidence suggest that the warming climate plays a vital role in driving certain types of extreme weather. How these extreme climates affect forest carbon sequestration capacity is unknown. This knowledge gap is critical in understanding positive feedbacks to global warming by changing the amount of carbon that forests can hold. Here, we used a perfect-deficit approach to identify forest canopy photosynthetic capacity (CPC) deficits and analyze how they correlate to climate extremes, based on data measured by the eddy covariance method at 26 forest sites with total of 146 site-years. We found that droughts severely alter the carbon sequestration capacities of evergreen broadleaf forest and deciduous broadleaf forest. In addition, the carbon sequestration capacities of Mediterranean forests are mostly sensitive to climate extremes while that of forests under marine climate are insensitive to climate extremes. Acknowledgements This research was financially supported by PSC-CUNY Award (PSC-CUNY-ENHC-44-83) and National Science Foundation (NSF-DEB-0949637).

  19. Machine processing of Landsat MSS data and DMA topographic data for forest cover type mapping

    NASA Technical Reports Server (NTRS)

    Fleming, M. D.; Hoffer, R. M.

    1979-01-01

    A study with the objective of developing and testing techniques which utilize both digital topographic data and Landsat MSS spectral data to map forest cover types is examined. Emphasis is given to the topographic distribution model (TDM), which combines point-by-point information about forest species, elevation, slope, and aspect to quantitatively describe topographic positions. Results show the stratified random sample approach to be very effective for developing the TDM, while the use of topographic data significantly improved the overall classification accuracy of forest cover types as compared to using spectral data alone.

  20. Minor forest products of the Pacific Northwest.

    Treesearch

    Elmer W. Shaw

    1949-01-01

    The evergreen forests of Washington and Oregon are the source of an interesting variety of so-called "minor products," Many of these forest sidelines are not well known. They are generally underestimated and quite often misunderstood. This is partly because the value and significance of these smaller, incidental products of the forest have long been...

  1. Phytophthora ramorum in Oregon forests: six years of detection, eradication, and disease spread

    Treesearch

    Alan Kanaskie; Everett Hansen; Ellen Goheen; Michael McWilliams; Paul Reeser; Wendy Sutton

    2009-01-01

    Phytophthora ramorum was first discovered in Southwest Oregon forests in 2001, where it was killing tanoak (Lithocarpus densiflorus) and infecting Pacific rhododendron (Rhododendron macrophyllum) and evergreen huckleberry (Vaccinium ovatum). At that time there were nine infested forest...

  2. [Effects of different type urban forest plantations on soil fertility].

    PubMed

    Sun, Hui-zhen; Chen, Ming-yue; Cai, Chun-ju; Zhu, Ning

    2009-12-01

    Aimed to study the effects of different urban forest plantations on soil fertility, soil samples were collected from eight mono-cultured plantations (Larix gmelinii, Pinus sylvestris var. mongolica, Pinus tabulaeformis var. mukdensis, Phellodendron amurense, Juglans mandshurica, Fraxinus mandshurica, Betula platyphylla, and Quercus mongolica) and one mixed plantation (P. sylvestris var. mongolica + F. mandshurica + Picea koraiensis + P. amurense + B. platyphylla) established in Northeast Forestry University's Urban Forestry Demonstration Research Base in the 1950s, with two sites of neighboring farmland and abandoned farmland as the control. The soils in broadleaved forest plantations except Q. mongolica were near neutral, those in mixed plantation, L. gmelinii, P. sylvestris var. mongolica, and P. tabulaeformis var. mukdensis were slightly acidic, and that in Q. mongolica was acidic. The contents of soil organic matter, total N and P, available P and K, and hydrolysable N tended to decrease with soil depth. There existed significant differences in the chemical indices of the same soil layers among different plantations. The soil fertility was decreased in the order of F. mandshurica > P. amurense > mixed plantation > J. mandshurica > B. platyphylla > abandoned farmland > farmland > P. sylvestris var. mongolica > L. gmelinii > Q. mongolica > P. tabulaeformis var. mukdensis, suggesting that the soil fertility in broadleaved forest plantations except Q. mongolica and in mixed plantation increased, while that in needle-leaved forest plantations tended to decrease.

  3. Ecological type classification for California: the Forest Service approach

    Treesearch

    Barbara H. Allen

    1987-01-01

    National legislation has mandated the development and use of an ecological data base to improve resource decision making, while State and Federal agencies have agreed to cooperate in standardizing resource classification and inventory data. In the Pacific Southwest Region, which includes nearly 20 million acres (8.3 million ha) in California, the Forest Service, U.S....

  4. Forest disturbance type differentially affects seasonal moose forage

    Treesearch

    R.A. Lautenschlager; Hewlette S. Crawford; Martin R. Stokes; Timothy L. Stone

    1997-01-01

    We examined the effects of forest disturbance on forage availability, moose (Alces alces) seasonal forage selection, and predicted in vivo digestibility in eastern Maine. Wet-mass estimates and dry-mass conversions of species consumed by 3 tamed moose were made throughout the year (late winter, early spring, late spring, summer, fall, early winter)...

  5. Relative growth rate variation of evergreen and deciduous savanna tree species is driven by different traits

    PubMed Central

    Tomlinson, Kyle W.; Poorter, Lourens; Bongers, Frans; Borghetti, Fabian; Jacobs, Loes; van Langevelde, Frank

    2014-01-01

    Background and Aims Plant relative growth rate (RGR) depends on biomass allocation to leaves (leaf mass fraction, LMF), efficient construction of leaf surface area (specific leaf area, SLA) and biomass growth per unit leaf area (net assimilation rate, NAR). Functional groups of species may differ in any of these traits, potentially resulting in (1) differences in mean RGR of groups, and (2) differences in the traits driving RGR variation within each group. We tested these predictions by comparing deciduous and evergreen savanna trees. Methods RGR, changes to biomass allocation and leaf morphology, and root non-structural carbohydrate reserves were evaluated for juveniles of 51 savanna species (34 deciduous, 17 evergreen) grown in a common garden experiment. It was anticipated that drivers of RGR would differ between leaf habit groups because deciduous species have to allocate carbohydrates to storage in roots to be able to flush leaves again, which directly compromises their LMF, whereas evergreen species are not subject to this constraint. Key Results Evergreen species had greater LMF and RGR than deciduous species. Among deciduous species LMF explained 27 % of RGR variation (SLA 34 % and NAR 29 %), whereas among evergreen species LMF explained between 2 and 17 % of RGR variation (SLA 32–35 % and NAR 38–62 %). RGR and LMF were (negatively) related to carbohydrate storage only among deciduous species. Conclusions Trade-offs between investment in carbohydrate reserves and growth occurred only among deciduous species, leading to differences in relative contribution made by the underlying components of RGR between the leaf habit groups. The results suggest that differences in drivers of RGR occur among savanna species because these have different selected strategies for coping with fire disturbance in savannas. It is expected that variation in the drivers of RGR will be found in other functional types that respond differently to particular disturbances. PMID

  6. Old-growth forests in the Sierra Nevada: by type in 1945 and 1993 and ownership in 1993.

    Treesearch

    Debby Beardsley; Charles Bolsinger; Ralph. Warbington

    1999-01-01

    This report presents estimates of old-growth forest area in the Sierra Nevada by forest type in 1993 and 1945 and by old-growth stand characteristics as they existed in 1993. Ecological old-growth definitions for each forest type are used.

  7. Regional factors rather than forest type drive the community structure of soil living oribatid mites (Acari, Oribatida).

    PubMed

    Erdmann, Georgia; Scheu, Stefan; Maraun, Mark

    2012-06-01

    Most European forests are managed by humans. However, the manner and intensity of management vary. While the effect of forest management on above-ground communities has been investigated in detail, effects on the below-ground fauna remain poorly understood. Oribatid mites are abundant microarthropods in forest soil and important decomposers in terrestrial ecosystems. Here, we investigated the effect of four forest types (i.e., managed coniferous forests; 30 and 70 years old managed beech forests; natural beech forests) on the density, diversity and community structure of oribatid mites (Acari). The study was replicated at three regions in Germany: the Swabian Alb, the Hainich and the Schorfheide. To relate changes in oribatid mite community structure to environmental factors, litter mass, pH, C and N content of litter, fine roots and C content of soil were measured. Density of oribatid mites was highest in the coniferous forests and decreased in the order 30 years old, 70 years old, and natural beech forests. Mass of the litter layer and density of oribatid mites were strongly correlated indicating that the litter layer is an important factor regulating oribatid mite densities. Diversity of oribatid mites was little affected by forest type indicating that they harbor similar numbers of niches. Species composition differed between the forest types, suggesting different types of niches. The community structure of oribatid mites differed more strongly between the three regions than between the forest types indicating that regional factors are more important than effects associated with forest type.

  8. Forest Types in the Lower Suwannee River Floodplain, Florida?-A Report and Interactive Map

    USGS Publications Warehouse

    Darst, M.R.; Light, H.M.; Lewis, L.J.; Sepulveda, A.A.

    2003-01-01

    A map of forest types in the lower Suwannee River floodplain, Florida, was created during a study conducted from 1996 to 2000 by the U.S. Geological Survey in cooperation with the Suwannee River Water Management District. The map is presented with this report on a compact disc with interactive viewing software. The forest map can be used by scientists for ecological studies in the floodplain based on land cover types and by landowners and management personnel making land use decisions. The study area is the 10-year floodplain of the lower Suwannee River from its confluence with the Santa Fe River to the lower limit of forests near the Gulf of Mexico. The floodplain is divided into three reaches: riverine (non-tidal), upper tidal, and lower tidal, due to changes in hydrology, vegetation, and soils with proximity to the coast. The 10-year floodplain covers about 21,170 hectares; nearly 88 percent of this area (18,580 hectares) is mapped as 14 major forest types. Approximately 29 percent (5,319 hectares) of these forests have been altered by agriculture or development. About 75 percent of the area of major forest types (13,994 hectares) is wetland forests and about 25 percent (4,586 hectares) is upland forests. Tidal wetland forests (8,955 hectares) cover a much greater area than riverine wetland forests (5,039 hectares). Oak/pine upland forests are present in the riverine and upper tidal reaches of the floodplain on elevations that are inundated only briefly during the highest floods. High bottomland hardwoods are present on the higher levees, ridges, and flats of the riverine reach where soils are usually sandy. Low bottomland hardwood forests are present in the riverine reach on swamp margins and low levees and flats that are flooded continuously for several weeks or longer every 1 to 3 years. Riverine swamps are present in the lowest and wettest areas of the non-tidal floodplain that are either inundated or saturated most of the time. Upper tidal bottomland

  9. Separating the effects of forest type and elevation on the diversity of litter invertebrate communities in a humid tropical forest in Puerto Rico.

    Treesearch

    BARBARA A. RICHARDSON; MICHAEL J. RICHARDSON; FELIPE N. SOTO-ADAMES

    2005-01-01

    1. The primary effects of climatic conditions on invertebrate litter communities, and the secondary effects of different forest types, were distinguished by using the sierra palm as a control in a natural experiment along an elevational gradient in the Luquillo Mountains. These mountains have three well-defined forest types along the gradient, with the palm occurring...

  10. ASSESSMENT OF MODIS LAI (W4) IN LOBLOLLY PINE (P. TAEDA) FOREST TYPE, APPOMATTOX, VIRGINIA

    EPA Science Inventory

    The United States Environmental Protection Agency initiated MODIS MODI5A2LAI validation research (2002) in the evergreen needle leaf biome, as defined in the MOD12 classification, in a regional study located in the southeastern United States.

  11. ASSESSMENT OF MODIS LAI (W4) IN LOBLOLLY PINE (P. TAEDA) FOREST TYPE, APPOMATTOX, VIRGINIA

    EPA Science Inventory

    The United States Environmental Protection Agency initiated MODIS MODI5A2LAI validation research (2002) in the evergreen needle leaf biome, as defined in the MOD12 classification, in a regional study located in the southeastern United States.

  12. Dynamics of the evergreen understory at Coweeta Hydrologic Laboratory, North Carolina

    NASA Astrophysics Data System (ADS)

    Dobbs, Marion Mcnamara

    Much attention today is directed toward vegetation dynamics and related issues of biotic diversity. Both environmental gradients and disturbance/land use history are important determinants of both the distributional pattern and the dynamics of many plant species. The southern Appalachian Mountains constitute a region of high plant and animal diversity and rapidly increasing development pressure with its consequent changes in land use. The remaining forested areas commonly include a significant evergreen understory (undergreen) composed of ericaceous shrubs, predominately Rhododendron maximum , which is believed to be expanding and exerting an inhibitory effect on the establishment of other species, thus impacting forest structure and composition. This study was an attempt to characterize this forest component, temporally and spatially, at the Coweeta Hydrologic Laboratory, North Carolina, in terms of a variety of topographic gradients as well as long-term (century) and short-term (decade) disturbance history, verify expansion, develop a surrogate soil moisture index for use in an explanatory model for undergreen pattern, and examine the feasibility of predicting the pattern of undergreen at one time based on knowledge of topographic relationships gained at an earlier time. A GIS was used for visual and areal comparisons; logistic regression was used for developing spatiotemporal explanatory models. Results indicate that aspect, stream proximity, and elevation are all important in explaining distributional pattern and dynamics of the undergreen at Coweeta, with R. maximum showing preference for moister areas and its common associate, Kalmia latifolia found more frequently in drier areas. The influence of these environmental factors differs between the larger Coweeta Basin, the site of experimental manipulations at the small watershed level since the 1930's, and the physically similar Dryman Fork Basin, relatively undisturbed since that time. There is an apparent

  13. The nitrogen budget for different forest types in the central Congo Basin

    NASA Astrophysics Data System (ADS)

    Bauters, Marijn; Verbeeck, Hans; Cizungu, Landry; Boeckx, Pascal

    2016-04-01

    Characterization of fundamental processes in different forest types is vital to understand the interaction of forests with their changing environment. Recent data analyses, as well as modeling activities have shown that the CO2 uptake by terrestrial ecosystems strongly depends on site fertility, i.e. nutrient availability. Accurate projections of future net forest growth and terrestrial CO2 uptake thus necessitate an improved understanding on nutrient cycles and how these are coupled to the carbon (C) cycle in forests. This holds especially for tropical forests, since they represent about 40-50% of the total carbon that is stored in terrestrial vegetation, with the Amazon basin and the Congo basin being the largest two contiguous blocks. However, due to political instability and reduced accessibility in the central Africa region, there is a strong bias in scientific research towards the Amazon basin. Consequently, central African forests are poorly characterized and their role in global change interactions shows distinct knowledge gaps, which is important bottleneck for all efforts to further optimize Earth system models explicitly including this region. Research in the Congo Basin region should combine assessments of both carbon stocks and the underlying nutrient cycles which directly impact the forest productivity. We set up a monitoring network for carbon stocks and nitrogen fluxes in four different forest types in the Congo Basin, which is now operative. With the preliminary data, we can get a glimpse of the differences in nitrogen budget and biogeochemistry of African mixed lowland rainforest, monodominant lowland forest, mixed montane forest and eucalypt plantations.

  14. Changes in forest productivity across Alaska consistent with biome shift

    Treesearch

    Peter S.A. Beck; Glenn P. Juday; Claire Alix; Valerie A. Barber; Stephen E. Winslow; Emily E. Sousa; Patricia Heiser; James D. Herriges; Scott J. Goetz

    2011-01-01

    Global vegetation models predict that boreal forests are particularly sensitive to a biome shift during the 21st century. This shift would manifest itself first at the biome's margins, with evergreen forest expanding into current tundra while being replaced by grasslands or temperate forest at the biome's southern edge. We evaluated changes in forest...

  15. Insight into the photosynthetic apparatus in evergreen and deciduous European oaks during autumn senescence using OJIP fluorescence transient analysis.

    PubMed

    Holland, V; Koller, S; Brüggemann, W

    2014-07-01

    Climate change is one of the major issues nowadays, and Mediterranean broadleaf species have been suggested to fill possible future gaps created by climate change in Central European forests. To provide a scientific-based foundation for such practical strategies, it is important to obtain a general idea about differences and similarities in the physiology of Central European and Mediterranean species. In the present study, we evaluated the onset of leaf senescence of a broad spectrum of oak species under the Central European climate in a common garden experiment. Degradation of the photosynthetic apparatus of evergreen (Quercus ilex, Q. suber), semi-evergreen (Q.×turneri, Q.×hispanica) and deciduous oaks (Q. robur, Q. cerris, Q. frainetto, Q. pubescens) was monitored as chlorophyll content and analysed chlorophyll fluorescence induction transients. In the deciduous species, a significant decline in chlorophyll content was observed during autumn/winter, with Q. pubescens showing the slowest decline. Analysis of fluorescence induction transients revealed a significant decline in quantum efficiency of the primary photochemistry and reaction centre density and later, a decrease in quantum efficiency of end acceptor reduction. Alterations in fluorescence parameters were compared to the decline in chlorophyll content, which occurred much more slowly than expected from the fluorescence data. The evergreen species showed no decline in chlorophyll content, nor different chlorophyll a fluorescence induction behaviour despite temperature falling below 0 °C. The hybrids showed intermediate behaviour between their parental evergreen and deciduous taxa.

  16. A global review on hydrological responses to forest change across multiple spatial scales: Importance of scale, climate, forest type and hydrological regime

    NASA Astrophysics Data System (ADS)

    Zhang, Mingfang; Liu, Ning; Harper, Richard; Li, Qiang; Liu, Kuan; Wei, Xiaohua; Ning, Dingyuan; Hou, Yiping; Liu, Shirong

    2017-03-01

    Despite extensive studies on hydrological responses to forest cover change in small watersheds, the hydrological responses to forest change and associated mechanisms across multiple spatial scales have not been fully understood. This review thus examined about 312 watersheds worldwide to provide a generalized framework to evaluate hydrological responses to forest cover change and to identify the contribution of spatial scale, climate, forest type and hydrological regime in determining the intensity of forest change related hydrological responses in small (<1000 km2) and large watersheds (⩾1000 km2). Key findings include: (1) the increase in annual runoff associated with forest cover loss is statistically significant at multiple spatial scales whereas the effect of forest cover gain is statistically inconsistent; (2) the sensitivity of annual runoff to forest cover change tends to attenuate as watershed size increases only in large watersheds; (3) annual runoff is more sensitive to forest cover change in water-limited watersheds than in energy-limited watersheds across all spatial scales; and (4) small mixed forest-dominated watersheds or large snow-dominated watersheds are more hydrologically resilient to forest cover change. These findings improve the understanding of hydrological response to forest cover change at different spatial scales and provide a scientific underpinning to future watershed management in the context of climate change and increasing anthropogenic disturbances.

  17. Detecting leaf phenology of seasonally moist tropical forests in South America with multi-temporal MODIS images.

    Treesearch

    Xiangming Xiao; Stephen Hagen; Qingyuan Zhang; Michael Keller; Berrien Moore III

    2006-01-01

    Leaf phenology of tropical evergreen forests affects carbon and water fluxes. In an earlier study of a seasonally moist evergreen tropical forest site in the Amazon basin, time series data of Enhanced Vegetation Index (EVI) from the VEGETATION and Moderate Resolution Imaging Spectroradiometer (MODIS) sensors showed an unexpected seasonal pattern, with higher EVI in the...

  18. The use of four band multispectral photography to identify forest cover types

    NASA Technical Reports Server (NTRS)

    Downs, S. W., Jr.

    1977-01-01

    Four-band multispectral aerial photography and a color additive viewer were employed to identify forest cover types in Northern Alabama. The multispectral photography utilized the blue, green, red and near-infrared spectral regions and was made with black and white infrared film. On the basis of color differences alone, a differentiation between conifers and hardwoods was possible; however, supplementary information related to forest ecology proved necessary for the differentiation of various species of pines and hardwoods.

  19. Drought-induced shifts in the floristic and functional composition of tropical forests in Ghana.

    PubMed

    Fauset, Sophie; Baker, Timothy R; Lewis, Simon L; Feldpausch, Ted R; Affum-Baffoe, Kofi; Foli, Ernest G; Hamer, Keith C; Swaine, Michael D

    2012-10-01

    The future of tropical forests under global environmental change is uncertain, with biodiversity and carbon stocks at risk if precipitation regimes alter. Here, we assess changes in plant functional composition and biomass in 19 plots from a variety of forest types during two decades of long-term drought in Ghana. We find a consistent increase in dry forest, deciduous, canopy species with intermediate light demand and a concomitant decrease in wet forest, evergreen, sub-canopy and shade-tolerant species. These changes in composition are accompanied by an increase in above-ground biomass. Our results indicate that by altering composition in favour of drought-tolerant species, the biomass stocks of these forests may be more resilient to longer term drought than short-term studies of severe individual droughts suggest.

  20. Ecological types of the eastern slope of the Wind River Range, Shoshone National Forest, Wyoming

    Treesearch

    Aaron F. Wells; Janis L. Boettinger; Kent E. Houston; David W. Roberts

    2015-01-01

    This guide presents a classification of the Ecological Types of the eastern slope of the Wind River Range (WRR) on the Shoshone National Forest in west-central Wyoming. Ecological Types integrate vegetation and environmental characteristics, including climate, geology, landform, and soils, into a comprehensive ecosystem classification. The three objectives are: (1)...

  1. Biodiversity assessment in incomplete inventories: leaf litter ant communities in several types of Bornean rain forest.

    PubMed

    Pfeiffer, Martin; Mezger, Dirk

    2012-01-01

    Biodiversity assessment of tropical taxa is hampered by their tremendous richness, which leads to large numbers of singletons and incomplete inventories in survey studies. Species estimators can be used for assessment of alpha diversity, but calculation of beta diversity is hampered by pseudo-turnover of species in undersampled plots. To assess the impact of unseen species, we investigated different methods, including an unbiased estimator of Shannon beta diversity that was compared to biased calculations. We studied alpha and beta diversity of a diverse ground ant assemblage from the Southeast Asian island of Borneo in different types of tropical forest: diperocarp forest, alluvial forest, limestone forest and heath forests. Forests varied in plant composition, geology, flooding regimes and other environmental parameters. We tested whether forest types differed in species composition and if species turnover was a function of the distance between plots at different spatial scales. As pseudo-turnover may bias beta diversity we hypothesized a large effect of unseen species reducing beta diversity. We sampled 206 ant species (25% singletons) from ten subfamilies and 55 genera. Diversity partitioning among the four forest types revealed that whereas alpha species richness and alpha Shannon diversity were significantly smaller than expected, beta-diversity for both measurements was significantly higher than expected by chance. This result was confirmed when we used the unbiased estimation of Shannon diversity: while alpha diversity was much higher, beta diversity differed only slightly from biased calculations. Beta diversity as measured with the Chao-Sørensen or Morisita-Horn Index correlated with distance between transects and between sample points, indicating a distance decay of similarity between communities. We conclude that habitat heterogeneity has a high influence on ant diversity and species turnover in tropical sites and that unseen species may have only

  2. Phylogenetic structure of ectomycorrhizal fungal communities of western hemlock changes with forest age and stand type.

    PubMed

    Lim, SeaRa; Berbee, Mary L

    2013-08-01

    On Vancouver Island, British Columbia, fertilization with nitrogen (N) and phosphorus (P) following clearcutting increases growth of western hemlock. To explore whether fertilization also resulted in ectomycorrhizal fungal communities that were more or less similar to neighboring unlogged stands, we sampled roots from western hemlock from three replicate plots from each of five different, well-characterized, forest stand types that differed in site type, and in logging and fertilization history. We harvested four samples of 100 ectomycorrhizal root tips from each plot, a total of 60 samples per stand type. From each sample, we analyzed fungal ribosomal internal transcribed spacers and 28S DNA, sequencing 15-29 clones per sample and 60-116 clones per plot. We detected 147 fungal operational taxonomic units among a total of 1435 sequences. Craterellus tubaeformis was frequently present and resulted in a pattern of phylogenetic overdispersion in the fungal communities. Fungal species composition was strongly correlated with foliar nitrogen concentration. However, other site quality factors were also important because the fertilized regenerating hemlock and mature hemlock-amabilis fir forests had similar foliar nitrogen content but little overlap in fungal species. Compared with unfertilized regenerating forests, fungal communities in N + P-fertilized regenerating forests had significantly more species overlap with old growth forests. However, the fungal communities of all regenerating forest were similar to one another and all differed significantly from older forests. By correlating fungal clades with habitats, this research improves understanding of how forest management can contribute to maintaining diverse ectomycorrhizal fungal communities across a landscape.

  3. Area changes for forest cover types in the United States, 1952 to 1997, with projections to 2050.

    Treesearch

    Ralph J. Alig; Brett J. Butler

    2004-01-01

    The United States has a diverse array of forest cover types on its 747 million acres of forest land. Forests in the United States have been shaped by many natural and human-caused forces, including climate, physiography, geology, soils, water, fire, land use changes, timber harvests, and other human interventions. The major purpose of this document is to describe area...

  4. Forecasting Forest Type and Age Classes in the Appalachian-Cumberland Subregion of the Central Hardwood Region

    Treesearch

    David N. Wear; Robert Huggett

    2011-01-01

    This chapter describes how forest type and age distributions might be expected to change in the Appalachian-Cumberland portions of the Central Hardwood Region over the next 50 years. Forecasting forest conditions requires accounting for a number of biophysical and socioeconomic dynamics within an internally consistent modeling framework. We used the US Forest...

  5. Ecophysiology of two Sonoran Desert evergreen shrubs during extreme drought

    USDA-ARS?s Scientific Manuscript database

    Recent drought across the arid Southwest US may be especially problematic for evergreen desert species that maintain leaves through dry periods. In July, 2002 we compared the ecophysiogical performance of the microphyllous creosotebush (Larrea tridentata) to broadleaved jojoba (Simmondisa chinensis...

  6. 7. VIEW OF ARIZONA CANAL ABOVE EVERGREEN, SHOWING LACK OF ...

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

    7. VIEW OF ARIZONA CANAL ABOVE EVERGREEN, SHOWING LACK OF SILT. OLD TOOTH MARKS OF DRAGLINE BUCKET MADE IN 1909 CALICHE BOTTOM WERE STILL VISIBLE Photographer: unknown. February 1938 - Arizona Canal, North of Salt River, Phoenix, Maricopa County, AZ

  7. Deciduous and evergreen trees differ in juvenile biomass allometries because of differences in allocation to root storage

    PubMed Central

    Tomlinson, Kyle W.; van Langevelde, Frank; Ward, David; Bongers, Frans; da Silva, Dulce Alves; Prins, Herbert H. T.; de Bie, Steven; Sterck, Frank J.

    2013-01-01

    Background and Aims Biomass partitioning for resource conservation might affect plant allometry, accounting for a substantial amount of unexplained variation in existing plant allometry models. One means of resource conservation is through direct allocation to storage in particular organs. In this study, storage allocation and biomass allometry of deciduous and evergreen tree species from seasonal environments were considered. It was expected that deciduous species would have greater allocation to storage in roots to support leaf regrowth in subsequent growing seasons, and consequently have lower scaling exponents for leaf to root and stem to root partitioning, than evergreen species. It was further expected that changes to root carbohydrate storage and biomass allometry under different soil nutrient supply conditions would be greater for deciduous species than for evergreen species. Methods Root carbohydrate storage and organ biomass allometries were compared for juveniles of 20 savanna tree species of different leaf habit (nine evergreen, 11 deciduous) grown in two nutrient treatments for periods of 5 and 20 weeks (total dry mass of individual plants ranged from 0·003 to 258·724 g). Key Results Deciduous species had greater root non-structural carbohydrate than evergreen species, and lower scaling exponents for leaf to root and stem to root partitioning than evergreen species. Across species, leaf to stem scaling was positively related, and stem to root scaling was negatively related to root carbohydrate concentration. Under lower nutrient supply, trees displayed increased partitioning to non-structural carbohydrate, and to roots and leaves over stems with increasing plant size, but this change did not differ between leaf habits. Conclusions Substantial unexplained variation in biomass allometry of woody species may be related to selection for resource conservation against environmental stresses, such as resource seasonality. Further differences in plant

  8. Ecosystem services capacity across heterogeneous forest types: understanding the interactions and suggesting pathways for sustaining multiple ecosystem services.

    PubMed

    Alamgir, Mohammed; Turton, Stephen M; Macgregor, Colin J; Pert, Petina L

    2016-10-01

    As ecosystem services supply from tropical forests is declining due to deforestation and forest degradation, much effort is essential to sustain ecosystem services supply from tropical forested landscapes, because tropical forests provide the largest flow of multiple ecosystem services among the terrestrial ecosystems. In order to sustain multiple ecosystem services, understanding ecosystem services capacity across heterogeneous forest types and identifying certain ecosystem services that could be managed to leverage positive effects across the wider bundle of ecosystem services are required. We sampled three forest types, tropical rainforests, sclerophyll forests, and rehabilitated plantation forests, over an area of 32,000m(2) from Wet Tropics bioregion, Australia, aiming to compare supply and evaluate interactions and patterns of eight ecosystem services (global climate regulation, air quality regulation, erosion regulation, nutrient regulation, cyclone protection, habitat provision, energy provision, and timber provision). On average, multiple ecosystem services were highest in the rainforests, lowest in sclerophyll forests, and intermediate in rehabilitated plantation forests. However, a wide variation was apparent among the plots across the three forest types. Global climate regulation service had a synergistic impact on the supply of multiple ecosystem services, while nutrient regulation service was found to have a trade-off impact. Considering multiple ecosystem services, most of the rehabilitated plantation forest plots shared the same ordination space with rainforest plots in the ordination analysis, indicating that rehabilitated plantation forests may supply certain ecosystem services nearly equivalent to rainforests. Two synergy groups and one trade-off group were identified. Apart from conserving rainforests and sclerophyll forests, our findings suggest two additional integrated pathways to sustain the supply of multiple ecosystem services from a

  9. A proper Land Cover and Forest Type Classification Scheme for Mexico

    NASA Astrophysics Data System (ADS)

    Gebhardt, S.; Maeda, P.; Wehrmann, T.; Argumedo Espinoza, J.; Schmidt, M.

    2015-04-01

    The imminent implementation of a REDD+ MRV system in Mexico in 2015, demanding operational annual land cover change reporting, requires highly accurate, annual and high resolution forest type maps; not only for monitoring but also to establish the historical baseline from the 1990s onwards. The employment of any supervised classifier demands exhaustive definition of land cover classes and the representation of all classes in the training stage. This paper reports the process of a data driven class separability analysis and the definition and application of a national land cover classification scheme. All Landsat data recorded over Mexico in the year 2000 with cloud coverage below 10 percent and a national digital elevation model have been used. Automatic wall-2-wall image classification has been performed trained by national reference data on land use and vegetation types with 66 classes. Validation has been performed against field plots of the national forest inventory. Groups of non-separable classes have subsequently been discerned by automatic iterative class aggregation. Class aggregations have finally been manually revised and modified towards a proposed national land cover classification scheme at 4 levels with 35 classes at the highest level including 13 classes for primary temperate and tropical forests, 2 classes for secondary temperate and tropical forest, 1 for induced or cultivated forest, as also 8 different scrubland classes. The remaining 11 classes cover agriculture, grassland, wetland, water bodies, urban and other vegetation land cover classes. The remaining 3 levels provide further hierarchic aggregations with 14, 10, and 8 classes, respectively. Trained by the relabeled training dataset wall-2-wall classification towards the 35 classes has been performed. The final national land cover dataset has been validated against more than 200,000 polygons randomly distributed all over the country with class labels derived by manual interpretation. The

  10. The affection of boreal forest changes on imbalance of Nature (Invited)

    NASA Astrophysics Data System (ADS)

    Tana, G.; Tateishi, R.

    2013-12-01

    Abstract: The balance of nature does not exist, and, perhaps, never has existed [1]. In other words, the Mother Nature is imbalanced at all. The Mother Nature is changing every moment and never returns to previous condition. Because of the imbalance of nature, global climate has been changing gradually. To reveal the imbalance of nature, there is a need to monitor the dynamic changes of the Earth surface. Forest cover and forest cover change have been grown in importance as basic variables for modelling of global biogeochemical cycles as well as climate [2]. The boreal area contains 1/3 of the earth's trees. These trees play a large part in limiting harmful greenhouse gases by aborbing much of the earth's carbon dioxide (CO2) [3]. The boreal area mainly consists of needleleaf evergreen forest and needleleaf deciduous forest. Both of the needleleaf evergreen forest and needleleaf deciduous forest play the important roles on the uptake of CO2. However, because of the dormant period of needleleaf evergreen forest are shorter than that of needleleaf deciduous forest, needleleaf evergreen forest makes a greater contribution to the absorbtion of CO2. Satellite sensor because of its ability to observe the Earth continuously, can provide the opportunity to monitor the dynamic changes of the Earth. In this study, we used the MODerate resolution Imaging Spectroradiometer (MODIS) satellite data to monitor the dynamic change of boreal forest area which are mainly consist from needleleaf evergreen forest and needleleaf deciduous forest during 2003-2012. Three years MODIS data from the year 2003, 2008 and 2012 were used to detect the forest changed area. A hybrid change detection method which combines the threshold method and unsupervised classification method was used to detect the changes of forest area. In the first step, the difference of Normalized Difference Vegetation Index (NDVI) of the three years were calculated and were used to extract the changed areas by the

  11. [Biomass and carbon storage of ground bryophytes under six types of young coniferous forest plantations].

    PubMed

    Bao, Weikai; Lei, Bo; Leng, Li

    2005-10-01

    This paper studied the biomass and carbon storage of the ground bryophytes under young Picea balfouriana (P), Pinus tabulaeformis (Y), Pinus armandii (H), Larix kaempferi (L), Picea balfouriana-Pinus tabulaeformis (P-Y), and Pinus tabulaeformis-Pinus armandii (Y-H) forest plantations in the upper reach of Minjiang River, Sichuan Province. The results showed that total biomass and carbon storage of ground bryophytes were relatively low, being 3.11 - 460.36 kg x hm(-2) and 1.12 +/- 0.03 x 168.95 +/- 0.92 kg x hm(-2), respectively. On plot level, only the bryophyte biomass between forest P and others, and the carbon storage between forest L and others were significantly different. The ground bryophyte had the highest biomass and carbon storage under forest P, while the lowest ones under forest H. Comprehensive analysis suggested that forest type and its structural feature might be the important factors determining the biomass and carbon storage of ground bryophytes, and thinning was an important measure to improve ground bryophyte growth and biomass production.

  12. Detecting change in advance tree regeneration using forest inventory data: the implications of type II error.

    PubMed

    Westfall, James A; McWilliams, William H

    2012-09-01

    Achieving adequate and desirable forest regeneration is necessary for maintaining native tree species and forest composition. Advance tree seedling and sapling regeneration is the basis of the next stand and serves as an indicator of future composition. The Pennsylvania Regeneration Study was implemented statewide to monitor regeneration on a subset of Forest Inventory and Analysis plots measured by the U.S. Forest Service. As management techniques are implemented to improve advance regeneration, assessments of the change in the forest resource are needed. When the primary focus is on detecting change, hypothesis tests should have small type II (β) error rates. However, most analyses are based on minimizing type I (α) error rates and type II error rates can be quite large. When type II error rates are high, actual improvements in regeneration can remain undetected and the methods that brought these improvements may be deemed ineffective. The difficulty in detecting significant change in advance regeneration when small type I error rates are given priority is illustrated. For statewide assessments, power (1-β) to detect changes in proportion of area having adequate advance regeneration is relatively weak (≤0.5) when the change is smaller than 0.05. For evaluations conducted at smaller spatial scales, such as wildlife management units, the reduced sample size results in only marginal power even when relatively large changes (≥0.20) in area proportion occur. For fixed sample sizes, analysts can consider accepting larger type I error rates to increase the probability of detecting change (smaller type II error rates) when it occurs, such that management methods that positively affect regeneration can be identified.

  13. Optimization of forest age-dependent light-use efficiency and its implications on climate-vegetation interactions in china

    NASA Astrophysics Data System (ADS)

    Li, Z.; Zhou, T.

    2015-04-01

    Forest's net primary productivity (NPP) is a key index in studying interactions of climate and vegetation, and accurate prediction of NPP is essential to understand the forests' response to climate change. The magnitude and trends of forest NPP not only depend on climate factors (e.g., temperature and precipitation), but also on the succession stages (i.e., forest stand age). Although forest stand age plays a significant role on NPP, it is usually ignored by remote sensing-based models. In this study, we used remote sensing data and meteorological data to estimate forest NPP in China based on CASA model, and then employed field observations to inversely estimate the parameter of maximum light-use efficiency (ɛmax) of forests in different stand ages. We further developed functions to describe the relationship between maximum light-use efficiency (ɛmax) and forest stand age, and estimated forest age-dependent NPP based on these functions. The results showed that ɛmax has changed according to forest types and the forest stand age. For deciduous broadleaf forest, the average ɛmax of young, middle-aged and mature forest are 0.68, 0.65 and 0.60 gC MJ-1. For evergreen broadleaf forest, the average ɛmax of young, middle-aged and mature forests are 1.05, 1.01 and 0.99 gC MJ-1. For evergreen needleleaf forest, the average ɛmax of young, middle-aged and mature forests are 0.72, 0.57 and 0.52 gC MJ-1.The NPP of young and middle-aged forests were underestimated based on a constant ɛmax. Young forests and middle-aged forests had higher ɛmax, and they were more sensitive to trends and fluctuations of climate change, so they led to greater annual fluctuations of NPP. These findings confirm the importance of considering forest stand age to the estimation of NPP and they are significant to study the response of forests to climate change.

  14. Element accumulation patterns of deciduous and evergreen tree seedlings on acid soils: implications for sensitivity to manganese toxicity.

    PubMed

    St Clair, Samuel B; Lynch, Jonathan P

    2005-01-01

    Foliar nutrient imbalances, including the hyperaccumulation of manganese (Mn), are correlated with symptoms of declining health in sensitive tree species growing on acidic forest soils. The objectives of this study were to: (1) compare foliar nutrient accumulation patterns of six deciduous (sugar maple (Acer saccharum Marsh.), red maple (Acer rubrum L.), red oak (Quercus rubra L.), white oak (Quercus alba L.), black cherry (Prunus serotina Ehrh.) and white ash (Fraxinus americana L.)) and three evergreen (eastern hemlock (Tsuga canadensis L.), white pine (Pinus strobus L.) and white spruce (Picea glauca (Moench) Voss.)) tree species growing on acidic forest soils; and (2) examine how leaf phenology and other traits that distinguish evergreen and deciduous tree species influence foliar Mn accumulation rates and sensitivity to excess Mn. For the first objective, leaf samples of seedlings from five acidic, non-glaciated field sites on Pennsylvania's Allegheny Plateau were collected and analyzed for leaf element concentrations. In a second study, we examined growth and photosynthetic responses of seedlings exposed to excess Mn in sand culture. In field samples, Mn in deciduous foliage hyperaccumulated to concentrations more than twice as high as those found in evergreen needles. Among species, sugar maple was the most sensitive to excess Mn based on growth and photosynthetic measurements. Photosynthesis in red maple and red oak was also sensitive to excess Mn, whereas white oak, black cherry, white ash and the three evergreen species were tolerant of excess Mn. Among the nine species, relative rates of photosynthesis were negatively correlated with foliar Mn concentrations, suggesting that photosynthetic sensitivity to Mn is a function of its rate of accumulation in seedling foliage.

  15. Natural Forest Biomass Estimation Based on Plantation Information Using PALSAR Data

    PubMed Central

    Avtar, Ram; Suzuki, Rikie; Sawada, Haruo

    2014-01-01

    Forests play a vital role in terrestrial carbon cycling; therefore, monitoring forest biomass at local to global scales has become a challenging issue in the context of climate change. In this study, we investigated the backscattering properties of Advanced Land Observing Satellite (ALOS) Phased Array L-band Synthetic Aperture Radar (PALSAR) data in cashew and rubber plantation areas of Cambodia. The PALSAR backscattering coefficient (σ0) had different responses in the two plantation types because of differences in biophysical parameters. The PALSAR σ0 showed a higher correlation with field-based measurements and lower saturation in cashew plants compared with rubber plants. Multiple linear regression (MLR) models based on field-based biomass of cashew (C-MLR) and rubber (R-MLR) plants with PALSAR σ0 were created. These MLR models were used to estimate natural forest biomass in Cambodia. The cashew plant-based MLR model (C-MLR) produced better results than the rubber plant-based MLR model (R-MLR). The C-MLR-estimated natural forest biomass was validated using forest inventory data for natural forests in Cambodia. The validation results showed a strong correlation (R2 = 0.64) between C-MLR-estimated natural forest biomass and field-based biomass, with RMSE  = 23.2 Mg/ha in deciduous forests. In high-biomass regions, such as dense evergreen forests, this model had a weaker correlation because of the high biomass and the multiple-story tree structure of evergreen forests, which caused saturation of the PALSAR signal. PMID:24465908

  16. Natural forest biomass estimation based on plantation information using PALSAR data.

    PubMed

    Avtar, Ram; Suzuki, Rikie; Sawada, Haruo

    2014-01-01

    Forests play a vital role in terrestrial carbon cycling; therefore, monitoring forest biomass at local to global scales has become a challenging issue in the context of climate change. In this study, we investigated the backscattering properties of Advanced Land Observing Satellite (ALOS) Phased Array L-band Synthetic Aperture Radar (PALSAR) data in cashew and rubber plantation areas of Cambodia. The PALSAR backscattering coefficient (σ0) had different responses in the two plantation types because of differences in biophysical parameters. The PALSAR σ0 showed a higher correlation with field-based measurements and lower saturation in cashew plants compared with rubber plants. Multiple linear regression (MLR) models based on field-based biomass of cashew (C-MLR) and rubber (R-MLR) plants with PALSAR σ0 were created. These MLR models were used to estimate natural forest biomass in Cambodia. The cashew plant-based MLR model (C-MLR) produced better results than the rubber plant-based MLR model (R-MLR). The C-MLR-estimated natural forest biomass was validated using forest inventory data for natural forests in Cambodia. The validation results showed a strong correlation (R2 = 0.64) between C-MLR-estimated natural forest biomass and field-based biomass, with RMSE  = 23.2 Mg/ha in deciduous forests. In high-biomass regions, such as dense evergreen forests, this model had a weaker correlation because of the high biomass and the multiple-story tree structure of evergreen forests, which caused saturation of the PALSAR signal.

  17. Damage and mortality assessment of redwood and mixed conifer forest types in Santa Cruz County following wildfire

    Treesearch

    Steve R. Auten; Nadia. Hamey

    2012-01-01

    On August 12, 2009, the Lockheed Fire ignited the west slope of the Santa Cruz Mountains burning approximately 7,819 acres. A mixture of vegetation types were in the path of the fire, including approximately 2,420 acres of redwood forest and 1,951 acres of mixed conifer forest types representative of the Santa Cruz Mountains. Foresters and land managers were left with...

  18. Equation to predict the (137)Cs leaching dynamic from evergreen canopies after a radio-cesium deposit.

    PubMed

    Loffredo, Nicolas; Onda, Yuichi; Hurtevent, Pierre; Coppin, Frédéric

    2015-09-01

    The Fukushima Daiishi nuclear power plant (FDNPP) accident led to a massive radionuclide deposition mainly onto Japanese forest canopies. In our previous study, an improved double exponential (IDE) equation including rainfall intensity was proposed to estimate the (137)Cs hydrological transport from evergreen canopies to the ground. This equation used two types of parameters, kinetic (k1 and k2) and leachable stock (A1 and A2). Those parameters have been estimated by adjusting them in the IDE equation in order to accurately describe the measured cumulative leached (137)Cs from canopies (k1 = 4.2E-04-5.0E-04 d(-1), k2 = 1.2E-02-1.7E-02 d(-1), A1 = 62-99 kBq/m(2), A2 = 25-61 kBq/m(2)). In this study, we linked the total leachable stock (Aleachable, a parameter of the IDE equation corresponding to A1 + A2) to a physiological criteria (the canopy closure CC, which can be measured with a simple camera equipped with a fish-eye objective). Furthermore, the kinetic parameters measured for Japanese cedar (k1 = 5.0E-04 d(-1), k2 = 1.2E-02 d(-1), and r12 = 0.22 (r12 = A1/A2) could also be used for two other coniferous species: Japanese cypress and spruce. This suggests that these parameters could be constants for coniferous forests. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Effects of Competition and Facilitation on Species Assemblage in Two Types of Tropical Cloud Forest

    PubMed Central

    Long, Wenxing; Zang, Runguo; Ding, Yi; Huang, Yunfeng

    2013-01-01

    Competition and facilitation between tree individuals are two kinds of non-random processes influencing the structure and functioning of forest communities, but how these two plant-plant interactions change along gradient of resources or environments remains very much a matter of debate. We developed a null model to test the size-distance regression, and assessed the effects of competition and facilitation (including interspecific interactions, intraspecific interactions and overall species interactions) on each adult tree species assemblage [diameter at breast height (dbh) ≥5 cm] across two types of tropical cloud forest with different environmental and resource regimes. The null model test revealed that 17% to 27% tree species had positive dbh-distance correlations while 11% to 19% tree species showed negative dbh-distance correlations within these two forest types, indicating that both competition and facilitation processes existed during the community assembly. The importance of competition for heterospecific species, and the intensity of competition for both heterospecific and overall species increased from high to low resources for all the shared species spanning the two forests. The importance of facilitation for conspecific and overall species, as well as that the intensity of facilitation for both heterospecific and conspecific species increased with increasing low air temperature stress for all the shared species spanning the two forests. Our results show that both competition and facilitation processes simultaneously affect parts of species assemblage in the tropical cloud forests. Moreover, the fact that nearly 50% species assemblage is not detected with our approaches suggest that tree species in these tropical forest systems are assembled with multiple ecological processes, and that there is a need to explore the processes other than the two biotic interactions in further researches. PMID:23565209

  20. Effects of competition and facilitation on species assemblage in two types of tropical cloud forest.

    PubMed

    Long, Wenxing; Zang, Runguo; Ding, Yi; Huang, Yunfeng

    2013-01-01

    Competition and facilitation between tree individuals are two kinds of non-random processes influencing the structure and functioning of forest communities, but how these two plant-plant interactions change along gradient of resources or environments remains very much a matter of debate. We developed a null model to test the size-distance regression, and assessed the effects of competition and facilitation (including interspecific interactions, intraspecific interactions and overall species interactions) on each adult tree species assemblage [diameter at breast height (dbh) ≥5 cm] across two types of tropical cloud forest with different environmental and resource regimes. The null model test revealed that 17% to 27% tree species had positive dbh-distance correlations while 11% to 19% tree species showed negative dbh-distance correlations within these two forest types, indicating that both competition and facilitation processes existed during the community assembly. The importance of competition for heterospecific species, and the intensity of competition for both heterospecific and overall species increased from high to low resources for all the shared species spanning the two forests. The importance of facilitation for conspecific and overall species, as well as that the intensity of facilitation for both heterospecific and conspecific species increased with increasing low air temperature stress for all the shared species spanning the two forests. Our results show that both competition and facilitation processes simultaneously affect parts of species assemblage in the tropical cloud forests. Moreover, the fact that nearly 50% species assemblage is not detected with our approaches suggest that tree species in these tropical forest systems are assembled with multiple ecological processes, and that there is a need to explore the processes other than the two biotic interactions in further researches.

  1. Modeling and spatially distributing forest net primary production at the regional scale.

    PubMed

    Mickler, Robert A; Earnhardt, Todd S; Moore, Jennifer A

    2002-04-01

    Forest, agricultural, rangeland, wetland, and urban landscapes have different rates of carbon sequestration and total carbon sequestration potential under alternative management options. Changes in the proportion and spatial distribution of land use could enhance or degrade that area's ability to sequester carbon in terrestrial ecosystems. As the ecosystems within a landscape change due to natural or anthropogenic processes, they may go from being a carbon sink to a carbon source or vice versa. Satellite image analysis has been tested for timely and accurate measurement of spatially explicit land use change and is well suited for use in inventory and monitoring of terrestrial carbon. The coupling of Landsat Thematic Mapper (TM) data with a physiologically based forest productivity model (PnET-II) and historic climatic data provides an opportunity to enhance field plot-based forest inventory and monitoring methodologies. We use periodic forest inventory data from the U.S. Department of Agriculture (USDA) Forest Service's Forest Inventory and Analysis (FIA) Program to obtain estimates of forest area and type and to generate estimates of carbon storage for evergreen, deciduous, and mixed-forest classes. The area information is used in an accuracy assessment of remotely sensed forest cover at the regional scale. The map display of modeled net primary production (NPP) shows a range of forest carbon storage potentials and their spatial relationship to other landscape features across the southern United States. This methodology addresses the potential for measuring and projecting forest carbon sequestration in the terrestrial biosphere of the southern United States.

  2. Seasonal variation in leaf characteristics and food selectionby larval noctuids on an evergreen Mediterranean shrub

    NASA Astrophysics Data System (ADS)

    Alonso, Conchita; Herrera, Carlos M.

    2000-07-01

    Despite year round availability of foliage, abundance of generalist noctuid larvae (Lepidoptera: Noctuidae) in evergreen-dominated Mediterranean forests has a narrow, distinct spring peak. This restricted larval period has been suggested to result in part from avoidance of the nutritionally poor mature foliage, and preference for nutritionally superior spring-produced young leaves. This study examines this hypothesis by (i) documenting differences in nutritional characteristics between expanding (April) and mature (June) young leaves of the evergreen Mediterranean shrub Daphne laureola L. (Thymelaeaceae), and (ii) experimentally studying the feeding preferences of noctuid larvae for young leaves, old leaves (≥ 1 yr old), and developing fruits of this species in one south-eastern Spanish locality. Young leaves of D. laureola declined in nutrient concentration and specific dry mass from April to June. The responses of noctuid larvae, in terms of both relative preference and total consumption, to this seasonal variation in chemical and physical features of young leaves were also investigated. When noctuid larvae were simultaneously offered young leaves, old leaves and developing fruits, they exhibited similar preferences for young leaves and developing fruits, and rejected old leaves developed during the previous year. Noctuid larvae did not modify their consumption of young leaves relative to old leaves and developing fruits in response to seasonal changes. Food selection patterns exhibited by D. laureola noctuid herbivores, notably the rejection of old leaves in favour of young ones, are consistent with the hypothesis relating restricted larval periods of these generalist consumers with the low food value of the previous season leaves of evergreen Mediterranean plants.

  3. Berry production in three whitebark pine forest types

    USGS Publications Warehouse

    Weaver, T.; Kendall, K.C.; Forcella, F.

    1990-01-01

    In the whitebark pine /whortleberry (Pinus albicaulis/Vaccinium scoparium) habitat type of southwestern Montana, whortleberry plants produced seven to 69 berries/m2 x yr in 1974. In subalpine fir (Abies lasiocarpa) habitat types of northwestern Montana, huckleberry plants (Vaccinium globulare) may produce from 13 to 228 berries/m2 X yr. While removal of competing trees increases production, thinning the understory apparently reduces berry production in direct proportion to the shrubs removed; there is no compensatory production indicative of shrub-shrub competition in fully vegetated plots. Fifty-to 100-fold variation in production among years in Vaccinium globulare berry production is attributed to variation in weather conditions.

  4. Photo series for quantifying forest residues in the coastal Douglas-fir-hemlock type.

    Treesearch

    W.G. Maxwell; F.R. Ward

    1976-01-01

    Six series of photographs display forest residue loading levels, by size classes, for areas of timber type and cutting practice. Information with each photo includes measured weights, volumes and other residue data, information about the timber stand and harvest or thinning actions and fuel ratings. These photo series provide...

  5. Forest-cover-type separation using RADARSAT-1 synthetic aperture radar imagery

    Treesearch

    Mark D. Nelson; Kathleen T. Ward; Marvin E. Bauer

    2009-01-01

    RADARSAT-1 synthetic aperture radar data, speckle reduction, and texture measures provided for separation among forest types within the Twin Cities metropolitan area, MN, USA. The highest transformed divergence values for 16-bit data resulted from speckle filtering while the highest values for 8-bit data resulted from the orthorectified image, before and after...

  6. Potential Changes in Tree Species Richness and Forest Community Types following Climate Change

    Treesearch

    Louis R. Iverson; Anantha M. Prasad

    2001-01-01

    Potential changes in tree species richness and forest community types were evaluated for the eastern United States according to five scenarios of future climate change resulting from a doubling of atmospheric carbon dioxide (CO2). DISTRIB, an empirical model that uses a regression tree analysis approach, was used to generate suitable habitat, or potential future...

  7. Vegetative characteristics of five forest types across a Lake States sulfate disposition gradient.

    Treesearch

    Lewis F. Ohmann; David F. Grigal; Stephen R. Shifley; William E. Berguson

    1994-01-01

    Presents the vegetative characteristics of the five forest types that comprised the study plots established to test the hypothesis that the wet sulfate deposition gradient across the Lake States is reflected in the amount of accumulated sulfur in soil and tree tissue, which in turn is reflected in tree growth.

  8. Influence of forest management alternatives and land type on susceptibility to fire in northern Wisconsin, USA

    Treesearch

    Eric J. Gustafson; Patrick A. Zollner; Brian R. Sturtevant; S. He Hong; David J. Mladenoff

    2004-01-01

    We used the LANDIS disturbance and succession model to study the effects of six alternative vegetation management scenarios on forest succession and the subsequent risk of canopy fire on a 2791 km2 landscape in northern Wisconsin, USA. The study area is a mix of fire-prone and fire-resistant land types. The alternatives vary the spatial...

  9. Forest types of the northern Rocky Mountains and their climatic controls

    Treesearch

    J. A. Larsen

    1930-01-01

    The purpose in this report is to describe the natural forest types of the northern Rocky Mountains in Montana and northern Idaho, to point out their natural distribution and chief silvical characteristics, and to show in what degree they are controlled by differences in topography and climate. Such information may be useful in laying the foundation for later, more...

  10. Community type classification of forest vegetation in young, mixed stands, interior Alaska. Forest Service research paper

    SciTech Connect

    Youngblood, A.

    1993-04-01

    A total of 53 upland mixed communities were sampled and classified into five community types: Populus tremuloides/Arctostaphylos uva-ursi, Populus tremuloides/Shepherdia canadensis, Betula papyrifera-Populus tremuloides/Viburnum edule, Betula papyrifera-Populus tremuloides/Alnus crispa and Picea glauca-Betula papyrifera/ Hylocomlum splendens. Community types were described by distribution and physical environment, vegetation composition, structural features, and relation to previously described vegetation units.

  11. Relictual amphibians and old-growth forest

    Treesearch

    H.H. Welsh

    1990-01-01

    Terrestrial and aquatic herpetofauna were sampled by pitfall traps, time-constrained searches, and areaconstrained searches (stream sites only) over a three-year period to examine the importance of forest age to amphibians and reptiles. Fifty-four terrestrial and 39 aquatic sites in Douglas-fir-dominated, mixed evergreen forests were located in southwestern Oregon and...

  12. Forest habitat types of northern Idaho: A second approximation

    Treesearch

    Stephen V. Cooper; Kenneth E. Neiman; David W. Roberts

    1991-01-01

    The addition of more than 900 plots to the Daubenmire's original 181-plot database has resulted in a refinement of their potential natural vegetation-based land classification for northern Idaho. A diagnostic, indicator species-based key is provided for field identification of the eight climax series, 46 habitat types, and 60 phases. Recognized syntaxa are...

  13. Neotropical primate communities: Effects of disturbance, resource production and forest type heterogeneity.

    PubMed

    Stevenson, Pablo R

    2015-12-18

    Undisturbed primate communities in the Neotropics are bottom-up structured as their biomass and species richness can be predicted from fruit production. However, the effects of fruit scarcity and the availability of forest types have not been fully analyzed, and seasonality is expected to differently affect small and large monkeys. The first aim of this study was to examine the effect of contrasting forest types within a location on the temporal variation in fruit production. The second was to assess the relative roles of disturbance, climate, patterns of fruit and leaf production, and plant composition on determining Neotropical primate communities. I compiled population density data for diurnal primate species from 154 sites to calculate species richness and assemblage biomass. Fruit abundance in the study sites was estimated from fruit trap data and phenology transects, and fruit variability was calculated as the monthly coefficient of variation (CV) and the length of the fruit scarcity period (LFSP). The results indicate that fruit production in floodplain forests is generally more variable than in terra firme forests, and this variation decreases in habitats with mixed forest types. Endozoochorous fruit production (based on fruit traps) and litter productivity were good predictors of the biomass of Neotropical primates (R(2)  = 0.83 and R(2)  = 0.59, respectively), but neither CV nor LFSP were good predictors. The biomass of large primates was independent of rainfall variation, but the biomass of small and medium sized monkeys was negatively correlated with temporal rainfall variability. Varzea forests tended to show higher biomass than those from terra firme and igapó. These results suggest that the production of fleshy fruits is the best predictor of the structure of primate assemblages in the Neotropics, but the effect of leaf quality and productivity remains to be investigated. Am. J. Primatol. © 2015 Wiley Periodicals, Inc.

  14. Urban Forests

    Treesearch

    David Nowak

    2016-01-01

    Urban forests (and trees) constitute the second forest resource considered in this report. We specifically emphasize the fact that agricultural and urban forests exist on a continuum defined by their relationship (and interrelationship) with a given landscape. These two forest types generally serve different purposes, however. Whereas agricultural forests are...

  15. [Soil enzyme activities under two forest types as affected by different levels of nitrogen deposition].

    PubMed

    Zhao, Yu-tao; Li, Xue-feng; Han, Shi-jie; Hu, Yan-ling

    2008-12-01

    A simulation test was conducted to study the change trends of soil cellulase, polyphenol oxidase, and sucrase activities under natural broadleaf-Korean pine (Pinus koraiensis) and secondary poplar (Populus davidiana) -birch (Betula platyphylla) mixed forests as affected by 0, 25, and 50 kg x hm(-2) x a(-1) of N deposition. The results showed that the effects of elevated N deposition on test enzyme activities varied with forest type, and short-term nitrogen addition could significantly affect the test enzyme activities. High N deposition decreased soil polyphyneol oxidase activity, and correspondingly, soil cellulase and sucrase activities also had a trend of decrease.

  16. Functional Trait Strategies of Trees in Dry and Wet Tropical Forests Are Similar but Differ in Their Consequences for Succession

    PubMed Central

    Lohbeck, Madelon; Lebrija-Trejos, Edwin; Martínez-Ramos, Miguel; Meave, Jorge A.; Poorter, Lourens; Bongers, Frans

    2015-01-01

    Global plant trait studies have revealed fundamental trade-offs in plant resource economics. We evaluated such trait trade-offs during secondary succession in two species-rich tropical ecosystems that contrast in precipitation: dry deciduous and wet evergreen forests of Mexico. Species turnover with succession in dry forest largely relates to increasing water availability and in wet forest to decreasing light availability. We hypothesized that while functional trait trade-offs are similar in the two forest systems, the successful plant strategies in these communities will be different, as contrasting filters affect species turnover. Research was carried out in 15 dry secondary forest sites (5-63 years after abandonment) and in 17 wet secondary forest sites (<1-25 years after abandonment). We used 11 functional traits measured on 132 species to make species-trait PCA biplots for dry and wet forest and compare trait trade-offs. We evaluated whether multivariate plant strategies changed during succession, by calculating a ‘Community-Weighted Mean’ plant strategy, based on species scores on the first two PCA-axes. Trait spectra reflected two main trade-off axes that were similar for dry and wet forest species: acquisitive versus conservative species, and drought avoiding species versus evergreen species with large animal-dispersed seeds. These trait associations were consistent when accounting for evolutionary history. Successional changes in the most successful plant strategies reflected different functional trait spectra depending on the forest type. In dry forest the community changed from having drought avoiding strategies early in succession to increased abundance of evergreen strategies with larger seeds late in succession. In wet forest the community changed from species having mainly acquisitive strategies to those with more conservative strategies during succession. These strategy changes were explained by increasing water availability during dry forest

  17. Functional trait strategies of trees in dry and wet tropical forests are similar but differ in their consequences for succession.

    PubMed

    Lohbeck, Madelon; Lebrija-Trejos, Edwin; Martínez-Ramos, Miguel; Meave, Jorge A; Poorter, Lourens; Bongers, Frans

    2014-01-01

    Global plant trait studies have revealed fundamental trade-offs in plant resource economics. We evaluated such trait trade-offs during secondary succession in two species-rich tropical ecosystems that contrast in precipitation: dry deciduous and wet evergreen forests of Mexico. Species turnover with succession in dry forest largely relates to increasing water availability and in wet forest to decreasing light availability. We hypothesized that while functional trait trade-offs are similar in the two forest systems, the successful plant strategies in these communities will be different, as contrasting filters affect species turnover. Research was carried out in 15 dry secondary forest sites (5-63 years after abandonment) and in 17 wet secondary forest sites (<1-25 years after abandonment). We used 11 functional traits measured on 132 species to make species-trait PCA biplots for dry and wet forest and compare trait trade-offs. We evaluated whether multivariate plant strategies changed during succession, by calculating a 'Community-Weighted Mean' plant strategy, based on species scores on the first two PCA-axes. Trait spectra reflected two main trade-off axes that were similar for dry and wet forest species: acquisitive versus conservative species, and drought avoiding species versus evergreen species with large animal-dispersed seeds. These trait associations were consistent when accounting for evolutionary history. Successional changes in the most successful plant strategies reflected different functional trait spectra depending on the forest type. In dry forest the community changed from having drought avoiding strategies early in succession to increased abundance of evergreen strategies with larger seeds late in succession. In wet forest the community changed from species having mainly acquisitive strategies to those with more conservative strategies during succession. These strategy changes were explained by increasing water availability during dry forest

  18. Stem water transport of Lithocarpus edulis, an evergreen oak with radial-porous wood.

    PubMed

    Hirose, Shigeki; Kume, Atsushi; Takeuchi, Shinichi; Utsumi, Yasuhiro; Otsuki, Kyoichi; Ogawa, Shigeru

    2005-02-01

    The stem water conducting system of an evergreen broad-leaved oak, Lithocarpus edulis (Mak.) Nakai, was investigated. Evergreen broad-leaved oaks (Lithocarpus, Castanopsis, Cyclobalanopsis, Quercus) belonging to the Quercoideae are a major component of Asian monsoon forests, and are characterized by the possession of radial-porous wood. A characteristic of radial-porous wood is the development of aggregate rays between radially oriented files of vessels. We measured the distribution of vessel lumen diameters in a stem cross section and calculated the theoretical water conductivity of the wood. The radial profile of the heat pulse velocity (HPV) was measured for an intact whole tree under field conditions and compared with the theoretical distribution of water conductivity. Soft X-ray photographs of frozen stem sections indicated that most of the vessel lumina were filled with water, including those of vessels more than 20 years old. Even when vessels were relatively wide (lumen diameters > 100 microm), cavitation was negligible. The rate of water uptake from the cut stem base correlated closely with HPV (r = 0.96), and HPV closely reflected the mean volume flow per stem sectional area (SFVS) around the sensor probes. However, the ray tissue sharply inhibited heat transfer, and the positioning of the probes strongly affected the absolute value of HPV. It was also found that HPV more closely reflected the mean sap flow velocity in the vessels than did SFVS.

  19. Evaluating revised biomass equations: are some forest types more equivalent than others?

    PubMed

    Hoover, Coeli M; Smith, James E

    2016-12-01

    In 2014, Chojnacky et al. published a revised set of biomass equations for trees of temperate US forests, expanding on an existing equation set (published in 2003 by Jenkins et al.), both of which were developed from published equations using a meta-analytical approach. Given the similarities in the approach to developing the equations, an examination of similarities or differences in carbon stock estimates generated with both sets of equations benefits investigators using the Jenkins et al. (For Sci 49:12-34, 2003) equations or the software tools into which they are incorporated. We provide a roadmap for applying the newer set to the tree species of the US, present results of equivalence testing for carbon stock estimates, and provide some general guidance on circumstances when equation choice is likely to have an effect on the carbon stock estimate. Total carbon stocks in live trees, as predicted by the two sets, differed by less than one percent at a national level. Greater differences, sometimes exceeding 10-15 %, were found for individual regions or forest type groups. Differences varied in magnitude and direction; one equation set did not consistently produce a higher or lower estimate than the other. Biomass estimates for a few forest type groups are clearly not equivalent between the two equation sets-southern pines, northern spruce-fir, and lower productivity arid western forests-while estimates for the majority of forest type groups are generally equivalent at the scales presented. Overall, the possibility of very different results between the Chojnacky and Jenkins sets decreases with aggregate summaries of those 'equivalent' type groups.

  20. Soil CO2 efflux among four coniferous forest types of Kashmir Himalaya, India.

    PubMed

    Dar, Javid Ahmad; Ganie, Khursheed Ahmad; Sundarapandian, Somaiah

    2015-11-01

    Soil CO2 efflux was measured in four different coniferous forest types (Cedrus deodara (CD), Pinus wallichiana (PW), mixed coniferous (MC), and Abies pindrow (AP)) for a period of 2 years (April 2012 to December 2013). The monthly soil CO2 efflux ranged from 0.8 to 4.1 μmoles CO2 m(-2) s(-1) in 2012 and 1.01 to 5.48 μmoles CO2 m(-2) s(-1) in 2013. The soil CO2 efflux rate was highest in PW forest type in both the years, while it was lowest in MC and CD forest types during 2012 and 2013, respectively. Soil temperature (TS) at a depth of 10 cm ranged from 3.8 to 19.4 °C in 2012 and 3.5 to 19.1 °C in 2013 in all the four forest types. Soil moisture (MS) ranged from 19.8 to 58.6% in 2012 and 18.5 to 58.6% in 2013. Soil CO2 efflux rate was found to be significantly higher in summer than the other seasons and least during winter. Soil CO2 efflux showed a significant positive relationship with TS (R2=0.52 to 0.74), SOC% (R2=0.67), pH (R2=0.68), and shrub biomass (R2=0.51), whereas, only a weak positive relationship was found with soil moisture (R2=0.16 to 0.41), tree density (R2=0.25), tree basal area (R2=0.01), tree biomass (R2=0.07), herb biomass (R2=0.01), and forest floor litter (R2=0.02). Thus, the study indicates that soil CO2 efflux in high mountainous areas is greatly influenced by seasons, soil temperature, and other environmental factors.

  1. Contrasting ozone sensitivity in related evergreen and deciduous shrubs.

    PubMed

    Calatayud, Vicent; Marco, Francisco; Cerveró, Júlia; Sánchez-Peña, Gerardo; Sanz, María José

    2010-12-01

    Plant responses to enhanced ozone levels have been studied in two pairs of evergreen-deciduous species (Pistacia terebinthus vs. P. lentiscus; Viburnum lantana vs. V. tinus) in Open Top Chambers. Ozone induced widespread visible injury, significantly reduced CO(2) assimilation and stomatal conductance (g(s)), impaired Rubisco efficiency and regeneration capacity (V(c,max,)J(max)) and altered fluorescence parameters only in the deciduous species. Differences in stomatal conductance could not explain the observed differences in sensitivity. In control plants, deciduous species showed higher superoxide dismutase (SOD) activity than their evergreen counterparts, suggesting metabolic differences that could make them more prone to redox imbalances. Ozone induced increases in SOD and/or peroxidase activities in all the species, but only evergreens were able to cope with the oxidative stress. The relevancy of these results for the effective ozone flux approach and for the current ozone Critical Levels is also discussed.

  2. Regional Distribution of Forest Height and Biomass from Multisensor Data Fusion

    NASA Technical Reports Server (NTRS)

    Yu, Yifan; Saatchi, Sassan; Heath, Linda S.; LaPoint, Elizabeth; Myneni, Ranga; Knyazikhin, Yuri

    2010-01-01

    Elevation data acquired from radar interferometry at C-band from SRTM are used in data fusion techniques to estimate regional scale forest height and aboveground live biomass (AGLB) over the state of Maine. Two fusion techniques have been developed to perform post-processing and parameter estimations from four data sets: 1 arc sec National Elevation Data (NED), SRTM derived elevation (30 m), Landsat Enhanced Thematic Mapper (ETM) bands (30 m), derived vegetation index (VI) and NLCD2001 land cover map. The first fusion algorithm corrects for missing or erroneous NED data using an iterative interpolation approach and produces distribution of scattering phase centers from SRTM-NED in three dominant forest types of evergreen conifers, deciduous, and mixed stands. The second fusion technique integrates the USDA Forest Service, Forest Inventory and Analysis (FIA) ground-based plot data to develop an algorithm to transform the scattering phase centers into mean forest height and aboveground biomass. Height estimates over evergreen (R2 = 0.86, P < 0.001; RMSE = 1.1 m) and mixed forests (R2 = 0.93, P < 0.001, RMSE = 0.8 m) produced the best results. Estimates over deciduous forests were less accurate because of the winter acquisition of SRTM data and loss of scattering phase center from tree ]surface interaction. We used two methods to estimate AGLB; algorithms based on direct estimation from the scattering phase center produced higher precision (R2 = 0.79, RMSE = 25 Mg/ha) than those estimated from forest height (R2 = 0.25, RMSE = 66 Mg/ha). We discuss sources of uncertainty and implications of the results in the context of mapping regional and continental scale forest biomass distribution.

  3. Geospatial monitoring and prioritization of forest fire incidences in Andhra Pradesh, India.

    PubMed

    Manaswini, G; Sudhakar Reddy, C

    2015-10-01

    Forest fire has been identified as one of the key environmental issue for long-term conservation of biodiversity and has impact on global climate. Spatially multiple observations are necessary for monitoring of forest fires in tropics for understanding conservation efficacy and sustaining biodiversity in protected areas. The present work was carried out to estimate the spatial extent of forest burnt areas and fire frequency using Resourcesat Advanced Wide Field Sensor (AWiFS) data (2009, 2010, 2012, 2013 and 2014) in Andhra Pradesh, India. The spatio-temporal analysis shows that an area of 7514.10 km(2) (29.22% of total forest cover) has been affected by forest fires. Six major forest types are distributed in Andhra Pradesh, i.e. semi-evergreen, moist deciduous, dry deciduous, dry evergreen, thorn and mangroves. Of the total forest burnt area, dry deciduous forests account for >75%. District-wise analysis shows that Kurnool, Prakasam and Cuddapah have shown >100 km(2) of burnt area every year. The total forest burnt area estimate covering protected areas ranges between 6.9 and 22.3% during the study period. Spatial burnt area analysis for protected areas in 2014 indicates 37.2% of fire incidences in the Nagarjunasagar Srisailam Tiger Reserve followed by 20.2 % in the Sri Lankamalleswara Wildlife Sanctuary, 20.1% in the Sri Venkateswara Wildlife Sanctuary and 17.4% in the Gundla Brahmeswaram Wildlife Sanctuary. The analysis of cumulative fire occurrences from 2009 to 2014 has helped in delineation of conservation priority hotspots using a spatial grid cell approach. Conservation priority hotspots I and II are distributed in major parts of study area including protected areas of the Nagarjunasagar Srisailam Tiger Reserve and Gundla Brahmeswaram Wildlife Sanctuary. The spatial database generated will be useful in studies related to influence of fires on species adaptability, ecological damage assessment and conservation planning.

  4. Regional Distribution of Forest Height and Biomass from Multisensor Data Fusion

    NASA Technical Reports Server (NTRS)

    Yu, Yifan; Saatchi, Sassan; Heath, Linda S.; LaPoint, Elizabeth; Myneni, Ranga; Knyazikhin, Yuri

    2010-01-01

    Elevation data acquired from radar interferometry at C-band from SRTM are used in data fusion techniques to estimate regional scale forest height and aboveground live biomass (AGLB) over the state of Maine. Two fusion techniques have been developed to perform post-processing and parameter estimations from four data sets: 1 arc sec National Elevation Data (NED), SRTM derived elevation (30 m), Landsat Enhanced Thematic Mapper (ETM) bands (30 m), derived vegetation index (VI) and NLCD2001 land cover map. The first fusion algorithm corrects for missing or erroneous NED data using an iterative interpolation approach and produces distribution of scattering phase centers from SRTM-NED in three dominant forest types of evergreen conifers, deciduous, and mixed stands. The second fusion technique integrates the USDA Forest Service, Forest Inventory and Analysis (FIA) ground-based plot data to develop an algorithm to transform the scattering phase centers into mean forest height and aboveground biomass. Height estimates over evergreen (R2 = 0.86, P < 0.001; RMSE = 1.1 m) and mixed forests (R2 = 0.93, P < 0.001, RMSE = 0.8 m) produced the best results. Estimates over deciduous forests were less accurate because of the winter acquisition of SRTM data and loss of scattering phase center from tree ]surface interaction. We used two methods to estimate AGLB; algorithms based on direct estimation from the scattering phase center produced higher precision (R2 = 0.79, RMSE = 25 Mg/ha) than those estimated from forest height (R2 = 0.25, RMSE = 66 Mg/ha). We discuss sources of uncertainty and implications of the results in the context of mapping regional and continental scale forest biomass distribution.

  5. [Stoichiometric characteristics of plant and soil C, N and P in different forest types in depressions between karst hills, southwest China].

    PubMed

    Yu, Yue-Feng; Peng, Wan-Xia; Song, Tong-Qing; Zeng, Fu-Ping; Wang, Ke-Lin; Wen, Li; Fan, Fu-Jing

    2014-04-01

    The stoichiometric properties of plant carbon (C), nitrogen (N) and phosphorus (P) and their relationships with soil were studied in six dominant plant communities in three forest types, i.e., plantation forest, secondary forest and primary forest in depressions between karst hills, southwest China. The C, N and P contents of both plant and soil had significant differences among the different forest types. Soil C and N contents were the highest in the secondary forest and the lowest in the plantation forest. Soil P content was the highest in the plantation forest and the lowest in the primary forest. Plant C and P contents were in the order of plantation forest > primary forest > secondary forest, and plant N content was the highest in the plantation forest and the lowest in the primary forest. Soil N:P,C:P and plant C:P ratios were significantly higher in the primary forest than in the other two forest types. There were no significant difference for the soil C:N ratio among the three forest types. Plant N:P ratio was the highest in the secondary forest and the lowest in the plantation forest. Plant C:N ratio was in the order of primary forest > plantation forest > secondary forest. There were significantly positive linear correlations between N and P contents, C:N and C:P ratios, C:P and N:P ratios of arbor leaves in the different forest types, and significant negative linear correlations between plant C:N and N:P ratios, and between soil C:N and N:P ratios. There were no significant correlations between plant and soil C, N, P contents and C:P ratio, suggesting that the supply of C, N and P from soil had little influence on plant C, N and P contents.

  6. Associations of Forest Type, Parasitism and Body Condition of Two European Passerines, Fringilla coelebs and Sylvia atricapilla

    PubMed Central

    Lüdtke, Bruntje; Moser, Isabelle; Santiago-Alarcon, Diego; Fischer, Markus; Kalko, Elisabeth KV.; Schaefer, H. Martin; Suarez-Rubio, Marcela; Tschapka, Marco; Renner, Swen C.

    2013-01-01

    Human-induced forest modification can alter parasite-host interactions and might change the persistence of host populations. We captured individuals of two widespread European passerines (Fringilla coelebs and Sylvia atricapilla) in southwestern Germany to disentangle the associations of forest types and parasitism by haemosporidian parasites on the body condition of birds. We compared parasite prevalence and parasite intensity, fluctuating asymmetries, leukocyte numbers, and the heterophil to lymphocyte ratio (H/L-ratio) among individuals from beech, mixed-deciduous and spruce forest stands. Based on the biology of bird species, we expected to find fewer infected individuals in beech or mixed-deciduous than in spruce forest stands. We found the highest parasite prevalence and intensity in beech forests for F. coelebs. Although, we found the highest prevalence in spruce forests for S. atricapilla, the highest intensity was detected in beech forests, partially supporting our hypothesis. Other body condition or health status metrics, such as the heterophil to lymphocyte ratio (H/L-ratio), revealed only slight differences between bird populations inhabiting the three different forest types, with the highest values in spruce for F. coelebs and in mixed-deciduous forests for S. atricapilla. A comparison of parasitized versus non-parasitized individuals suggests that parasite infection increased the immune response of a bird, which was detectable as high H/L-ratio. Higher infections with blood parasites for S. atricapilla in spruce forest indicate that this forest type might be a less suitable habitat than beech and mixed-deciduous forests, whereas beech forests seem to be a suboptimal habitat regarding parasitism for F. coelebs. PMID:24339923

  7. Delineating Tree Types in a Complex Tropical Forest Setting Using High Resolution Multispectral Satellite Imagery

    NASA Astrophysics Data System (ADS)

    Cross, M.

    2016-12-01

    An improved process for the identification of tree types from satellite imagery for tropical forests is needed for more accurate assessments of the impact of forests on the global climate. La Selva Biological Station in Costa Rica was the tropical forest area selected for this particular study. WorldView-3 imagery was utilized because of its high spatial, spectral and radiometric resolution, its availability, and its potential to differentiate species in a complex forest setting. The first-step was to establish confidence in the high spatial and high radiometric resolution imagery from WorldView-3 in delineating tree types within a complex forest setting. In achieving this goal, ASD field spectrometer data were collected of specific tree species to establish solid ground control within the study site. The spectrometer data were collected from the top of each specific tree canopy utilizing established towers located at La Selva Biological Station so as to match the near-nadir view of the WorldView-3 imagery. The ASD data was processed utilizing the spectral response functions for each of the WorldView-3 bands to convert the ASD data into a band specific reflectivity. This allowed direct comparison of the ASD spectrometer reflectance data to the WorldView-3 multispectral imagery. The WorldView-3 imagery was processed to surface reflectance using two standard atmospheric correction procedures and the proprietary DigitalGlobe Atmospheric Compensation (AComp) product. The most accurate correction process was identified through comparison to the spectrometer data collected. A series of statistical measures were then utilized to access the accuracy of the processed imagery and which imagery bands are best suited for tree type identification. From this analysis, a segmentation/classification process was performed to identify individual tree type locations within the study area. It is envisioned the results of this study will improve traditional forest classification

  8. Habitat-dependent ambient noise: Consistent spectral profiles in two African forest types

    NASA Astrophysics Data System (ADS)

    Slabbekoorn, Hans

    2004-12-01

    Many animal species use acoustic signals to attract mates, to defend territories, or to convey information that may contribute to their fitness in other ways. However, the natural environment is usually filled with competing sounds. Therefore, if ambient noise conditions are relatively constant, acoustic interference can drive evolutionary changes in animal signals. Furthermore, masking noise may cause acoustic divergence between populations of the same species if noise conditions differ consistently among habitats. In this study, ambient noise was sampled in a replicate set of sites in two habitat types in Cameroon: contiguous rainforest and ecotone forest patches north of the rainforest. The noise characteristics of the two forest types show significant and consistent differences. Multiple samples taken at two rainforest sites in different seasons vary little and remain distinct from those in ecotone forest. The rainforest recordings show many distinctive frequency bands, with a general increase in amplitude from low to high frequencies. Ecotone forest only shows a distinctive high-frequency band at some parts of the day. Habitat-dependent abiotic and biotic sound sources and to some extent habitat-dependent sound transmission are the likely causes of these habitat-dependent noise spectra. .

  9. Effects of pioneer tree species hyperabundance on forest fragments in northeastern Brazil.

    PubMed

    Tabarelli, Marcelo; Aguiar, Antonio V; Girão, Luciana C; Peres, Carlos A; Lopes, Ariadna V

    2010-12-01

    Despite many studies on fragmentation of tropical forests, the extent to which plant and animal communities are altered in small, isolated forest fragments remains obscure if not controversial. We examined the hypothesis that fragmentation alters the relative abundance of tree species with different vegetative and reproductive traits. In a fragmented landscape (670 km(2) ) of the Atlantic Forest of northeastern Brazil, we categorized 4056 trees of 182 species by leafing pattern, reproductive phenology, and morphology of seeds and fruit. We calculated relative abundance of traits in 50 1-ha plots in three types of forest configurations: forest edges, small forest fragments (3.4-83.6 ha), and interior of the largest forest fragment (3500 ha, old growth). Although evergreen species were the most abundant across all configurations, forest edges and small fragments had more deciduous and semideciduous species than interior forest. Edges lacked supra-annual flowering and fruiting species and had more species and stems with drupes and small seeds than small forest fragments and forest interior areas. In an ordination of species similarity and life-history traits, the three types of configurations formed clearly segregated clusters. Furthermore, the differences in the taxonomic and functional (i.e., trait-based) composition of tree assemblages we documented were driven primarily by the higher abundance of pioneer species in the forest edge and small forest fragments. Our work provides strong evidence that long-term transitions in phenology and seed and fruit morphology of tree functional groups are occurring in fragmented tropical forests. Our results also suggest that edge-induced shifts in tree assemblages of tropical forests can be larger than previously documented.

  10. Accident rates and types among self-employed private forest owners.

    PubMed

    Lindroos, Ola; Burström, Lage

    2010-11-01

    Half of all Swedish forests are owned by private individuals, and at least 215,000 people work in these privately owned forest holdings. However, only lethal accidents are systematically monitored among self-employed forest workers. Therefore, data from the registries of the Swedish Work Environment Authority, the Labor Insurance Organization and the regional University Hospital in Umeå were gathered to allow us to perform a more in-depth assessment of the rate and types of accidents that occurred among private forest owners. We found large differences between the registries in the type and number of accidents that were reported. We encountered difficulties in defining "self-employed forest worker" and also in determining whether the accidents that did occur happened during work or leisure time. Consequently, the estimates for the accident rate that we obtained varied from 32 to > or = 4300 injured persons per year in Sweden, depending on the registry that was consulted, the definition of the sample population that was used, and the accident severity definition that was employed. Nevertheless, the different registries gave a consistent picture of the types of accidents that occur while individuals are participating in self-employed forestry work. Severe accidents were relatively common, as self-employed forestry work fatalities constituted 7% of the total number of fatalities in the work authority registry. Falling trees were associated with many of these fatal accidents as well as with accidents that resulted in severe non-fatal injuries. Thus, unsafe work methods appeared more related to the occurrence of an accident than the equipment that was being used at the time of the accident (e.g., a chainsaw). Improvement of the workers' skills should therefore be considered to be an important prevention measure that should be undertaken in this field. The challenges in improving the safety in these smallest of companies, which fall somewhere between the purview of

  11. Midday stomatal conductance is more related to stem rather than leaf water status in subtropical deciduous and evergreen broadleaf trees.

    PubMed

    Zhang, Yong-Jiang; Meinzer, Frederick C; Qi, Jin-Hua; Goldstein, Guillermo; Cao, Kun-Fang

    2013-01-01

    Midday depressions in stomatal conductance (g(s) ) and photosynthesis are common in plants. The aim of this study was to understand the hydraulic determinants of midday g(s) , the coordination between leaf and stem hydraulics and whether regulation of midday g(s) differed between deciduous and evergreen broadleaf tree species in a subtropical cloud forest of Southwest (SW) China. We investigated leaf and stem hydraulics, midday leaf and stem water potentials, as well as midday g(s) of co-occurring deciduous and evergreen tree species. Midday g(s) was correlated positively with midday stem water potential across both groups of species, but not with midday leaf water potential. Species with higher stem hydraulic conductivity and greater daily reliance on stem hydraulic capacitance were able to maintain higher stem water potential and higher g(s) at midday. Deciduous species exhibited significantly higher stem hydraulic conductivity, greater reliance on stem capacitance, higher stem water potential and g(s) at midday than evergreen species. Our results suggest that midday g(s) is more associated with midday stem than with leaf water status, and that the functional significance of stomatal regulation in these broadleaf tree species is probably for preventing stem xylem dysfunction.

  12. Soil Microbial Biomass, Basal Respiration and Enzyme Activity of Main Forest Types in the Qinling Mountains

    PubMed Central

    Cheng, Fei; Peng, Xiaobang; Zhao, Peng; Yuan, Jie; Zhong, Chonggao; Cheng, Yalong; Cui, Cui; Zhang, Shuoxin

    2013-01-01

    Different forest types exert essential impacts on soil physical-chemical characteristics by dominant tree species producing diverse litters and root exudates, thereby further regulating size and activity of soil microbial communities. However, the study accuracy is usually restricted by differences in climate, soil type and forest age. Our objective is to precisely quantify soil microbial biomass, basal respiration and enzyme activity of five natural secondary forest (NSF) types with the same stand age and soil type in a small climate region and to evaluate relationship between soil microbial and physical-chemical characters. We determined soil physical-chemical indices and used the chloroform fumigation-extraction method, alkali absorption method and titration or colorimetry to obtain the microbial data. Our results showed that soil physical-chemical characters remarkably differed among the NSFs. Microbial biomass carbon (Cmic) was the highest in wilson spruce soils, while microbial biomass nitrogen (Nmic) was the highest in sharptooth oak soils. Moreover, the highest basal respiration was found in the spruce soils, but mixed, Chinese pine and spruce stands exhibited a higher soil qCO2. The spruce soils had the highest Cmic/Nmic ratio, the greatest Nmic/TN and Cmic/Corg ratios were found in the oak soils. Additionally, the spruce soils had the maximum invertase activity and the minimum urease and catalase activities, but the maximum urease and catalase activities were found in the mixed stand. The Pearson correlation and principle component analyses revealed that the soils of spruce and oak stands obviously discriminated from other NSFs, whereas the others were similar. This suggested that the forest types affected soil microbial properties significantly due to differences in soil physical-chemical features. PMID:23840671

  13. Soil microbial biomass, basal respiration and enzyme activity of main forest types in the Qinling Mountains.

    PubMed

    Cheng, Fei; Peng, Xiaobang; Zhao, Peng; Yuan, Jie; Zhong, Chonggao; Cheng, Yalong; Cui, Cui; Zhang, Shuoxin

    2013-01-01

    Different forest types exert essential impacts on soil physical-chemical characteristics by dominant tree species producing diverse litters and root exudates, thereby further regulating size and activity of soil microbial communities. However, the study accuracy is usually restricted by differences in climate, soil type and forest age. Our objective is to precisely quantify soil microbial biomass, basal respiration and enzyme activity of five natural secondary forest (NSF) types with the same stand age and soil type in a small climate region and to evaluate relationship between soil microbial and physical-chemical characters. We determined soil physical-chemical indices and used the chloroform fumigation-extraction method, alkali absorption method and titration or colorimetry to obtain the microbial data. Our results showed that soil physical-chemical characters remarkably differed among the NSFs. Microbial biomass carbon (Cmic) was the highest in wilson spruce soils, while microbial biomass nitrogen (Nmic) was the highest in sharptooth oak soils. Moreover, the highest basal respiration was found in the spruce soils, but mixed, Chinese pine and spruce stands exhibited a higher soil qCO2. The spruce soils had the highest Cmic/Nmic ratio, the greatest Nmic/TN and Cmic/Corg ratios were found in the oak soils. Additionally, the spruce soils had the maximum invertase activity and the minimum urease and catalase activities, but the maximum urease and catalase activities were found in the mixed stand. The Pearson correlation and principle component analyses revealed that the soils of spruce and oak stands obviously discriminated from other NSFs, whereas the others were similar. This suggested that the forest types affected soil microbial properties significantly due to differences in soil physical-chemical features.

  14. Effect of forest and soil type on microbial biomass carbon and respiration

    NASA Astrophysics Data System (ADS)

    Habashi, Hashem

    2016-09-01

    The aim of study was to evaluate the variation of soil microbial biomass carbon (Cmic) and microbial respiration (MR) in three types soil (Chromic Cambisols, Chromic Luvisols and Eutric Leptosols) of mixed beech forest (Beech- Hornbeam and Beech- Maple). Soil was randomly sampled from 0-10 cm layer (plant litter removed), 90 soil samples were taken. Cmic determined by the fumigation-extraction method and MR by closed bottle method. Soil Corg, Ntot and pH were measured. There are significant differences between the soil types concerning the Cmic content and MR. These parameters were highest in Chromic Cambisols following Chromic Luvisols, while the lowest were in Eutric Leptosols. A similar trend of Corg and Ntot was observed in studied soils. Two-way ANOVA indicated that soil type and forest type have significantly effect on the most soil characteristics. Chromic Cambisols shows a productive soil due to have the maximum Cmic, MR, Corg and Ntot. In Cambisols under Beech- Maple forest the Cmic value and soil C/N ratio were higher compared to Beech-Hornbeam (19.5 and 4.1 mg C g-1, and 16.3 and 3.3, respectively). This fact might be indicated that Maple litter had more easy decomposable organic compounds than Hornbeam. According to regression analysis, 89 and 68 percentage of Cmic variability could explain by soil Corg and Ntot respectively.

  15. [Soil microbial community structure of two types of forests in the mid-subtropics of China].

    PubMed

    Han, Shi-zhong; Gao, Ren; Li, Ai-ping; Ma, Hong-liang; Yin, Yun-feng; Si, You-tao; Chen, Shi-dong; Zheng, Qun-rui

    2015-07-01

    Soil microbial community structures were analyzed by biomarker method of phospholipid fatty acid (PLFA) for a natural forest dominated by Castanopsis fabri (CF) and an adjacent plantation of Cunninghamia lanceolata (CL) in the mid-subtropics of China. The results showed that the amounts of total PLFAs, bacterial PLFAs, fungal PLFAs, gram-positive bacterial PLFAs and gramnegative bacterial PLFAs in the 0-10 cm soil layer were higher than in the 10-20 cm soil layer, and each type of PLFAs in CF were higher than in CL. In either soil layer of the two forest types, the contents of bacterial PLFAs were significantly higher than those of fungal PLFAs. In the two forests, the contents of bacterial PLFAs accounted for 44%-52% of total PLFAs, while the contents of fungal PLFAs just accounted for 6%-8%, indicating the bacteria were dominant in the soils of the two vegetation types. Principal component analysis showed that the influence of vegetation types was greater than soil depth on the microbial community structures. Correlation analysis showed that gram-negative bacterial PLFAs, gram-positive bacterial PLFAs and bacterial PLFAs were significantly negatively correlated with pH, positively with water content, and the PLFAs of main soil microorganism groups were significantly positively correlated with soil total nitrogen, organic carbon, C/N and ammonium.

  16. Differential hypogeous sporocarp production from Nothofagus dombeyi and N. pumilio forests in southern Argentina.

    PubMed

    Nouhra, Eduardo R; Urcelay, Carlos; Longo, M Silvana; Fontenla, Sonia

    2012-01-01

    Mycorrhizal fungi that form hypogeous sporocarps are an important component of the temperate forest soil community. In many regions, such as the Nothofagus forest in the Patagonian Andes, this group of fungi has been poorly studied. Here we examined the spring and autumn community composition of "sequestrate fungi", based on sporocarp production in pure forests of Nothofagus dombeyi (evergreen) and N. pumilio (deciduous). We investigated the possible relationships between these communities and environmental factors over 2 y. The rarefaction curves and the minimal richness estimates converged at nearly the same level for each forest type, and the asymptotes suggested that the sampling effort was sufficient to capture most of the hypogeous sporocarp richness in these forest stands. In total 27 species were recovered. Basidiomycota, Ascomycota and Glomeromycota respectively accounted for nine, two and one genera. Species richness of hypogeous sporocarps varied in relation to forest type but not to season (fall and spring), whereas sporocarp biomass varied according to an interaction between season and forest type. Species richness and sporocarp biomass were positively correlated with rainfall and negatively correlated with altitude. In addition sporocarp species richness was positively related to number of trees per transect. We found that two different forest stands, each dominated by different species of Nothofagus, exhibited different hypogeous sporocarp communities.

  17. Modellig the Foliage Seasonal Carbon Cycle in Tropical Forests

    NASA Astrophysics Data System (ADS)

    De Weirdt, M.; Verbeeck, H.; Maignan, F.; Peylin, P.; Ciais, P.; Moreau, I.; Hanert, E.; Defourny, P.; Steppe, K.

    2011-01-01

    Phenological modeling for tropical forests remains poorly developed and many global ecosystem models, like ORCHIDEE, assume that canopy dynamics of evergreen tropical forests show no seasonality. The current ORCHIDEE scheme fails to adequately model the seasonal variability of carbon fluxes observed in tropical evergreen forests. A better description of the underlying mechanisms that drive tropical forest canopy seasonal photosynthesis dynamics and phenology could possibly overcome this problem. To address this issue, seasonal variations in leaf phenology and photosynthesis dynamics for evergreen tropical forests were introduced and validated against in-situ carbon flux measurements. Both a seasonal photosynthetic capacity and a litterfall seasonality were introduced in ORCHIDEE and the resulting increased dry season photosynthesis and changed seasonal Net Ecosystem Exchange (NEE) patterns for flux tower sites in the Amazon were evaluated.

  18. Forest structure and landscape patterns in the subalpine lodgepole pine type: A procedure for quantifying past and present conditions. Forest Service general technical report

    SciTech Connect

    Arno, S.F.; Reinhardt, E.D.; Scott, J.H.

    1993-02-01

    The report presents a method of quantitatively representing the mosaic of stand types on a small landscape in the subalpine lodgepole pine forest type. The method utilizes macroplots placed systematically on a transect grid. Structure and composition of both current and past stands are inventoried. Procedures for data analysis and interpretation are illustrated for a lodgepole pine landscape in Montana.

  19. Phenol compounds in solutions of soils of different types in the central forest state biosphere reserve

    NASA Astrophysics Data System (ADS)

    Malinina, M. S.; Ivanilova, S. V.

    2008-04-01

    The interannual, seasonal, and daily dynamics of the contents of phenol compounds in the soil solution of a peat-podzolic-gleyic soil in the southern taiga are considered. The concentrations of phenol compounds in the studied soil remain relatively stable. In the solutions obtained from different soil types, the main limiting factor is the degree of hydromorphism, which manifests itself via the biological factor—the intensity of the microorganisms activity and the composition and quality of the forest litters.

  20. Large-scale fungal diversity assessment in the Andean Yungas forests reveals strong community turnover among forest types along an altitudinal gradient.

    PubMed

    Geml, József; Pastor, Nicolás; Fernandez, Lisandro; Pacheco, Silvia; Semenova, Tatiana A; Becerra, Alejandra G; Wicaksono, Christian Y; Nouhra, Eduardo R

    2014-05-01

    The Yungas, a system of tropical and subtropical montane forests on the eastern slopes of the Andes, are extremely diverse and severely threatened by anthropogenic pressure and climate change. Previous mycological works focused on macrofungi (e.g. agarics, polypores) and mycorrhizae in Alnus acuminata forests, while fungal diversity in other parts of the Yungas has remained mostly unexplored. We carried out Ion Torrent sequencing of ITS2 rDNA from soil samples taken at 24 sites along the entire latitudinal extent of the Yungas in Argentina. The sampled sites represent the three altitudinal forest types: the piedmont (400-700 m a.s.l.), montane (700-1500 m a.s.l.) and montane cloud (1500-3000 m a.s.l.) forests. The deep sequence data presented here (i.e. 4 108 126 quality-filtered sequences) indicate that fungal community composition correlates most strongly with elevation, with many fungi showing preference for a certain altitudinal forest type. For example, ectomycorrhizal and root endophytic fungi were most diverse in the montane cloud forests, particularly at sites dominated by Alnus acuminata, while the diversity values of various saprobic groups were highest at lower elevations. Despite the strong altitudinal community turnover, fungal diversity was comparable across the different zonal forest types. Besides elevation, soil pH, N, P, and organic matter contents correlated with fungal community structure as well, although most of these variables were co-correlated with elevation. Our data provide an unprecedented insight into the high diversity and spatial distribution of fungi in the Yungas forests. © 2014 John Wiley & Sons Ltd.

  1. Phenotypic plasticity of the basidiomata of Thelephora sp. (Thelephoraceae) in tropical forest habitats.

    PubMed

    Ramirez-Lópezl, Itzel; Ríos, Margarita Villegas; Cano-Santana, Zenón

    2013-03-01

    Phenotypic plasticity in macroscopic fungi has been poorly studied in comparison to plants or animals and only general aspects of these changes have been described. In this work, the phenotypic variation in the basidiomata of Thelephora sp. (Thelephoraceae) was examined, as well as some aspects of its ecology and habitat, using 24 specimens collected in the tropical forests of the Chamela Biological Station, Jalisco, Mexico. Our observations showed that this taxon has clavarioid basidiomata that can become resupinate during development and growth if they are in contact with rocks, litter or live plants, establishing in the latter only an epiphytic relationship. This tropical species may form groups of up to 139 basidiomata over an area of 32.2m2, and in both types of vegetation (tropical sub-evergreen and deciduous forest) were primarily located on steep (>20 degree) South-facing slopes. It is found under closed canopy in both tropical forests, but its presence in sub-evergreen forests is greater than expected.

  2. [Litter decomposition of typical forests along an altitude gradient in Mt. Shennongjia, Hubei, China].

    PubMed

    Pan, Dong-Rong; Liu, Xiao-Ni; Shen, Guo-Zhen; Xie, Zong-Qiang; Luo, Lu; Liu, Lei

    2013-12-01

    Based on the litterbag method, we explored the decomposition dynamics of the litter from the evergreen broad-leaved forests, the mixed evergreen and deciduous broad-leaved forests, and the deciduous broad-leaved forests along an altitude gradient in Mt. Shennongjia, Hubei, China. According to the decomposition rate, the decomposition of the litter could be divided into early stage (0-360 days) and later stage (361-720 days). With the increase of altitude, the mass loss rates of the litter from the three types of forests at the early stage were 2.62-4.08 times that of the later stage, the litter decomposition rates at the early stage were 2.71, 1.72 and 2.69 times of that at the later stage, respectively, and 95% decomposition of the litter needed 3.84, 4.54 and 4.16 years respectively. The decomposition rate at the later stage was significantly correlated with C/N, and the contents of N, hemicelluloses, cellulose and lignin.

  3. A non-parametric, supervised classification of vegetation types on the Kaibab National Forest using decision trees

    Treesearch

    Suzanne M. Joy; R. M. Reich; Richard T. Reynolds

    2003-01-01

    Traditional land classification techniques for large areas that use Landsat Thematic Mapper (TM) imagery are typically limited to the fixed spatial resolution of the sensors (30m). However, the study of some ecological processes requires land cover classifications at finer spatial resolutions. We model forest vegetation types on the Kaibab National Forest (KNF) in...

  4. Trying Hard: Interdisciplinary Programs at the Evergreen State College

    ERIC Educational Resources Information Center

    Levensky, Mark

    1977-01-01

    Experience at Evergreen has shown that it is possible to make interdisciplinary programs work well and to do so at an undergraduate, open-admission, liberal arts state college. About one-third of the students are enrolled in a full-time interdisciplinary program of 40 to 90 students, staffed by two to five faculty members. (Editor/LBH)

  5. Institutional Reviews by State-Level Agencies: The Evergreen Study.

    ERIC Educational Resources Information Center

    Chance, William

    An institutional review of Evergreen State College that was undertaken by the Washington Council for Postsecondary Education is described. A review of a higher education institution by a state agency was unusual but was a compromise action by the 1977 state legislature, which also considered closing the college, whose institutional cost level was…

  6. The Evergreen State College Bulletin 1973-74.

    ERIC Educational Resources Information Center

    Evergreen State Coll., Olympia, Washington.

    Presented in this college bulletin are (1) an introduction including information on admissions, registration, accreditation, philosophy, and affirmative action; (2) a survey of the academic programs; (3) a section on the learning process as it is approached at Evergreen; (4) a listing and description of current programs offered; (5) descriptions…

  7. An Instructional Guide for Ethnic Studies at Evergreen Valley College.

    ERIC Educational Resources Information Center

    Chavez, Mauro

    Guidelines and conceptual parameters are presented for ethnic studies courses at Evergreen Valley College (EVC). Introductory material discusses the requirement that all associate degree students complete three units of ethnic studies; presents general guidelines for ethnic studies; defines "ethnic-racial minority"; and suggests criteria for…

  8. A Student Government Guidebook for Evergreen Valley College.

    ERIC Educational Resources Information Center

    Chavez, Mauro

    Designed to help develop informed and capable student leadership in student affairs at Evergreen Valley College (EVC), this student government guide and text for Government 91 focuses on the major leadership needs and objectives of student government within a participatory framework. After an explanation of course objectives and requirements,…

  9. March Madness! A Look at Evergreen Parenting Topics

    ERIC Educational Resources Information Center

    Parenting for High Potential, 2014

    2014-01-01

    Many topics in the world of gifted are evergreen. Whether it be 1964 or 2014, they're still relevant. In this issue, "Parenting for High Potential" takes a peek into the archives to look at topics that have run in various March issues of PHP through the years. No matter where you are on the gifted journey, there's something here for…

  10. A Student Government Guidebook for Evergreen Valley College.

    ERIC Educational Resources Information Center

    Chavez, Mauro

    Designed to help develop informed and capable student leadership in student affairs at Evergreen Valley College (EVC), this student government guide and text for Government 91 focuses on the major leadership needs and objectives of student government within a participatory framework. After an explanation of course objectives and requirements,…

  11. An Instructional Guide for Ethnic Studies at Evergreen Valley College.

    ERIC Educational Resources Information Center

    Chavez, Mauro

    Guidelines and conceptual parameters are presented for ethnic studies courses at Evergreen Valley College (EVC). Introductory material discusses the requirement that all associate degree students complete three units of ethnic studies; presents general guidelines for ethnic studies; defines "ethnic-racial minority"; and suggests criteria for…

  12. Comparative vessel anatomy of arctic deciduous and evergreen dicots.

    PubMed

    Gorsuch, D M; Oberbauer, S F; Fisher, J B

    2001-09-01

    Arctic tundra plant species exhibit striking variation in leaf character and growth form. Both are likely related to differences in vessel anatomy, and all may affect responses to climate changes in the Arctic. To investigate the relationships among leaf character, growth form, vessel anatomy, and susceptibility to freeze-thaw-induced xylem cavitation, xylem vessel characteristics were compared among six deciduous and six evergreen arctic dicot species of erect and prostrate growth forms. We hypothesized that deciduous and erect species would have larger and longer vessels than evergreen and cushion/mat-forming species. Vessel lengths, diameters, and densities were measured for each species. Theoretical vessel flow rates were calculated using Poiseuille's law for ideal capillaries. Flow rates were used to determine the susceptibility of vessels to cavitation induced by freeze-thaw events that may become more frequent with global warming. Vessel diameters were larger in deciduous species compared to evergreens, and in shrubs/trees vs. cushion/mat-forming plants. Vessel length distributions, however, did not differ for growth form or leaf character. Vessel density was greater in cushion/mat-forming species than in shrub/tree species. Deciduous plants showed a greater contribution to total conductivity by relatively larger vessels than evergreens. One of the deciduous species, Vaccinium uliginosum, is predicted to be susceptible to freeze-thaw-induced cavitation. These results have important implications for future arctic species composition and plant community structure.

  13. March Madness! A Look at Evergreen Parenting Topics

    ERIC Educational Resources Information Center

    Parenting for High Potential, 2014

    2014-01-01

    Many topics in the world of gifted are evergreen. Whether it be 1964 or 2014, they're still relevant. In this issue, "Parenting for High Potential" takes a peek into the archives to look at topics that have run in various March issues of PHP through the years. No matter where you are on the gifted journey, there's something here for…

  14. Variation in carbon stocks on different slope aspects in seven major forest types of temperate region of Garhwal Himalaya, India.

    PubMed

    Sharma, C M; Gairola, Sumeet; Baduni, N P; Ghildiyal, S K; Suyal, Sarvesh

    2011-09-01

    The present study was undertaken in seven major forest types of temperate zone (1500 m a.s.l. to 3100 m a.s.l.) of Garhwal Himalaya to understand the effect of slope aspects on carbon (C) density and make recommendations for forest management based on priorities for C conservation/sequestration. We assessed soil organic carbon (SOC) density, tree density, biomass and soil organic carbon (SOC) on four aspects, viz. north/east (NE), north/west (NW), south-east (SE) and south-west (SW), in forest stands dominated by Abies pindrow, Cedrus deodara, Pinus roxburghii, Cupressus torulosa, Quercus floribunda, Quercus semecarpifolia and Quercus leucotrichophora. TCD ranged between 77.3 CMg ha⁻¹ on SE aspect (Quercus leucotrichophora forest) and 291.6 CMg ha⁻¹ on NE aspect (moist Cedrus deodara forest). SOC varied between 40.3 CMg ha⁻¹ on SW aspect (Himalayan Pinus roxburghii forest) and 177.5 CMg ha⁻¹ on NE aspect (moist Cedrus deodara forest). Total C density (SOC+TCD) ranged between 118.1 CMg ha⁻¹ on SW aspect (Himalayan Pinus roxburghii forest) and 469.1 CMg ha⁻¹ on NE aspect (moist Cedrus deodara forest). SOC and TCD were significantly higher on northern aspects as compared with southern aspects. It is recommended that for C sequestration, the plantation silviculture be exercised on northern aspects, and for C conservation purposes, mature forest stands growing on northern aspects be given priority.

  15. Monitoring forest succession in the NC Piedmont using a Landsat time series

    NASA Astrophysics Data System (ADS)

    Hakkenberg, C.

    2013-12-01

    Forest successional stage, an indicator of compositional turnover and structural development in forest stands, is a central factor in efforts to quantify productivity and carbon sequestration, nutrient cycling, wildlife habitat and species diversity in forests. Despite its importance, only recently have advances in remote sensing and computer processing provided researchers with the synoptic view necessary for landscape-scale mapping of successional change. This research reports on results from the first segment of a multi-part project to ascertain the rate and distribution of structural development and compositional turnover in the North Carolina Piedmont. The Piedmont study site was selected for hosting a diversity of forest community types and possessing a recent history characterized by dynamic land cover transitions. In this study, a Landsat time series stack (LTSS) from 1984-2011 is used at a tri-annual time step to quantify landscape-scale forest successional processes using temporal trajectory analysis rather than space-for-time substitutions. After controlling for phenological noise in the LTSS trajectory by downscaling a AVHRR/MODIS-derived phenological profile, relative change in spectral values, rather than absolute radiometric values, is used to assess characteristic temporal signatures in spectral space that map onto successional processes. Model validation from CVS and Duke forest plot data confirm the utility of fitting nonlinear regression to a Tasseled Cap Angle time series as a means to monitor regeneration rates for disturbed forests that return to a closed canopy within the period. While results fail to find a consistent change pattern across the study site, spatial autocorrelation in summer increment NDVI change vectors indicate clustering of successional processes characterized by high rates of evergreen establishment in disturbed areas and a transition from evergreen to deciduous communities in closed-canopy forests.

  16. Changes in Forest Soil Properties in Different Successional Stages in Lower Tropical China

    PubMed Central

    Li, Yuelin; Yang, Fangfang; Ou, Yangxu; Zhang, Deqiang; Liu, Juxiu; Chu, Guowei; Zhang, Yaru; Otieno, Dennis; Zhou, Guoyi

    2013-01-01

    Background Natural forest succession often affects soil physical and chemical properties. Selected physical and chemical soil properties were studied in an old-growth forest across a forest successional series in Dinghushan Nature Reserve, Southern China. Methodology/Principal Findings The aim was to assess the effects of forest succession change on soil properties. Soil samples (0–20 cm depth) were collected from three forest types at different succession stages, namely pine (Pinus massoniana) forest (PMF), mixed pine and broadleaf forest (PBMF) and monsoon evergreen broadleaf forest (MEBF), representing early, middle and advanced successional stages respectively. The soil samples were analyzed for soil water storage (SWS), soil organic matter (SOM), soil microbial biomass carbon (SMBC), pH, NH4+-N, available potassium (K), available phosphorus (P) and microelements (available copper (Cu), available zinc (Zn), available iron (Fe) and available boron (B)) between 1999 and 2009. The results showed that SWS, SOM, SMBC, Cu, Zn, Fe and B concentrations were higher in the advanced successional stage (MEBF stage). Conversely, P and pH were lower in the MEBF but higher in the PMF (early successional stage). pH, NH4+-N, P and K declined while SOM, Zn, Cu, Fe and B increased with increasing forest age. Soil pH was lower than 4.5 in the three forest types, indicating that the surface soil was acidic, a stable trend in Dinghushan. Conclusion/Significance These findings demonstrated significant impacts of natural succession in an old-growth forest on the surface soil nutrient properties and organic matter. Changes in soil properties along the forest succession gradient may be a useful index for evaluating the successional stages of the subtropical forests. We caution that our inferences are drawn from a pseudo-replicated chronosequence, as true replicates were difficult to find. Further studies are needed to draw rigorous conclusions regarding on nutrient dynamics in

  17. Changes in forest soil properties in different successional stages in lower tropical China.

    PubMed

    Li, Yuelin; Yang, Fangfang; Ou, Yangxu; Zhang, Deqiang; Liu, Juxiu; Chu, Guowei; Zhang, Yaru; Otieno, Dennis; Zhou, Guoyi

    2013-01-01

    Natural forest succession often affects soil physical and chemical properties. Selected physical and chemical soil properties were studied in an old-growth forest across a forest successional series in Dinghushan Nature Reserve, Southern China. The aim was to assess the effects of forest succession change on soil properties. Soil samples (0-20 cm depth) were collected from three forest types at different succession stages, namely pine (Pinus massoniana) forest (PMF), mixed pine and broadleaf forest (PBMF) and monsoon evergreen broadleaf forest (MEBF), representing early, middle and advanced successional stages respectively. The soil samples were analyzed for soil water storage (SWS), soil organic matter (SOM), soil microbial biomass carbon (SMBC), pH, NH4(+)-N, available potassium (K), available phosphorus (P) and microelements (available copper (Cu), available zinc (Zn), available iron (Fe) and available boron (B)) between 1999 and 2009. The results showed that SWS, SOM, SMBC, Cu, Zn, Fe and B concentrations were higher in the advanced successional stage (MEBF stage). Conversely, P and pH were lower in the MEBF but higher in the PMF (early successional stage). pH, NH4(+)-N, P and K declined while SOM, Zn, Cu, Fe and B increased with increasing forest age. Soil pH was lower than 4.5 in the three forest types, indicating that the surface soil was acidic, a stable trend in Dinghushan. These findings demonstrated significant impacts of natural succession in an old-growth forest on the surface soil nutrient properties and organic matter. Changes in soil properties along the forest succession gradient may be a useful index for evaluating the successional stages of the subtropical forests. We caution that our inferences are drawn from a pseudo-replicated chronosequence, as true replicates were difficult to find. Further studies are needed to draw rigorous conclusions regarding on nutrient dynamics in different successional stages of forest.