Science.gov

Sample records for intensive forest biomass

  1. Forest soil carbon is threatened by intensive biomass harvesting

    PubMed Central

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

    2015-01-01

    Forests play a key role in the carbon cycle as they store huge quantities of organic carbon, most of which is stored in soils, with a smaller part being held in vegetation. While the carbon storage capacity of forests is influenced by forestry, the long-term impacts of forest managers’ decisions on soil organic carbon (SOC) remain unclear. Using a meta-analysis approach, we showed that conventional biomass harvests preserved the SOC of forests, unlike intensive harvests where logging residues were harvested to produce fuelwood. Conventional harvests caused a decrease in carbon storage in the forest floor, but when the whole soil profile was taken into account, we found that this loss in the forest floor was compensated by an accumulation of SOC in deeper soil layers. Conversely, we found that intensive harvests led to SOC losses in all layers of forest soils. We assessed the potential impact of intensive harvests on the carbon budget, focusing on managed European forests. Estimated carbon losses from forest soils suggested that intensive biomass harvests could constitute an important source of carbon transfer from forests to the atmosphere (142–497 Tg-C), partly neutralizing the role of a carbon sink played by forest soils. PMID:26530409

  2. Forest soil carbon is threatened by intensive biomass harvesting

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

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

  3. Forest soil carbon is threatened by intensive biomass harvesting.

    PubMed

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

    2015-11-04

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

  4. VARIABILITY IN NET PRIMARY PRODUCTION AND CARBON STORAGE IN BIOMASS ACROSS OREGON FORESTS - AN ASSESSMENT INTEGRATING DATA FROM FOREST INVENTORIES, INTENSIVE SITES, AND REMOTE SENSING. (R828309)

    EPA Science Inventory

    We used a combination of data from USDA Forest Service inventories, intensive
    chronosequences, extensive sites, and satellite remote sensing, to estimate biomass
    and net primary production (NPP) for the forested region of western Oregon. The
    study area was divided int...

  5. Education Highlights: Forest Biomass

    ScienceCinema

    Barone, Rachel; Canter, Christina

    2016-07-12

    Argonne intern Rachel Barone from Ithaca College worked with Argonne mentor Christina Canter in studying forest biomass. This research will help scientists develop large scale use of biofuels from forest biomass.

  6. Education Highlights: Forest Biomass

    SciTech Connect

    Barone, Rachel; Canter, Christina

    2016-01-27

    Argonne intern Rachel Barone from Ithaca College worked with Argonne mentor Christina Canter in studying forest biomass. This research will help scientists develop large scale use of biofuels from forest biomass.

  7. Sensitivity of Backscatter Intensity of ALOS/PALSAR to Above-ground Biomass and Other Biophysical Parameters of Boreal Forests in Alaska and Japan

    NASA Astrophysics Data System (ADS)

    Suzuki, R.; Hayashi, M.; Kim, Y.; Ishii, R.; Kobayashi, H.; Shoyama, K.; Adachi, M.; Takahashi, A.; Saigusa, N.; Ito, A.

    2012-12-01

    For the better understanding of the carbon cycle in the global environment, investigations on the spatio-temporal variation of the carbon stock which is stored as vegetation biomass is important. The backscatter intensity of "Phased Array type L-band Synthetic Aperture Radar (PALSAR)" onboard the satellite "Advanced Land Observing Satellite (ALOS)" provides us the information which is applicable to estimate the forest above-ground biomass (AGB). This study examines the sensitivity of the backscatter intensity of ALOS/PALSAR to the forest AGB and other biophysical parameters (tree height, tree diameter at breast height (DBH), and tree stand density) for boreal forests in two geographical regions of Alaska and Kushiro, northern Japan, and compares the sensitivities in two regions. In Alaska, a forest survey was executed in the south-north transect (about 300 km long) along a trans-Alaska pipeline which profiles the ecotone from the boreal forest to tundra in 2007. Forest AGBs and other biophysical parameters at 29 forests along the transect were measured by Bitterlich method. In Kushiro, a forest survey was carried out at 42 forests in 2011 and those parameters were similarly obtained by Bitterlich method. 20 and 2 scenes of ALOS/PALSAR FBD Level 1.5 data that cover the regions in Alaska and Kushiro, respectively, were collected and mosaicked. Backscatter intensities of ALOS/PALSAR in HH (horizontally polarized transmitted and horizontally polarized received) and HV (horizontally polarized transmitted and vertically polarized received) modes were compared with the forest AGB and other biophysical parameters. The intensity generally increased with the increase of those biophysical parameters in both HV and HH modes, but the intensity in HV mode generally had a stronger correlation to those parameters than in HH mode in both Alaska and Kushiro. The HV intensity had strong correlation to the forest AGB and DBH, while weak correlation to the tree stand density in Alaska

  8. Long-term effects of clear cutting and intensive biomass harvesting on the nitrogen leaching to groundwater in the boreal forest environment

    NASA Astrophysics Data System (ADS)

    Kubin, Eero

    2013-04-01

    Clear-cutting and site preparation cause the greatest changes in site conditions and to the environment. The oldest research carried out within the boreal coniferous forest zone on the leaching of nutrients into watercourses was conducted in Sweden in the early 1970s. Also in Finland, the effect of clear-cutting and site preparation on the quality of surface runoff has been monitored since 1974 and into the groundwater, after waste wood harvesting, since 1986. Recently intensive biomass harvest has been rapidly increasing and nowadays about seven percent of the total consumption of energy in Finland comes from forest energy. The consumption derived from wood-based fuels is as much as 23 per cent of the total energy. Thus study and understanding forest ecosystems function is nowadays facing new challenges, especially when harvested forest energy, especially stumps, course disturbances and more water penetrating into the soil and groundwater in addition to other ecosystem changes. According the long term-monitoring results nitrate nitrogen seems to be the foremost nutrient leached into the groundwater as a consequence of forestry operations. The effects of clear-cutting on nitrate nitrogen leaching and concentrations in surface water have been shown to last only a few years, but the long-term property of increasing groundwater concentrations, have persisted 25 years which has not reported earlier from other sites. Clear-cutting increases the input of precipitation, but in northern areas this cannot be the main reason for the higher values. The greater part of the increased concentrations is due to the decomposition of cutting waste and humus. This is interesting in relation to intensive biomass harvesting. The availability and the quality of water are strongly influenced by forests. The relationship between forests and water is therefore a critical issue that must be accorded high priority also when developing forest biomass harvesting for energy. To develop best

  9. The potential of detecting intermediate-scale biomass and canopy interception in a coniferous forest using cosmic-ray neutron intensity measurements and neutron transport modeling

    NASA Astrophysics Data System (ADS)

    Andreasen, M.; Looms, M. C.; Bogena, H. R.; Desilets, D.; Zreda, M. G.; Sonnenborg, T. O.; Jensen, K. H.

    2014-12-01

    The water stored in the various compartments of the terrestrial ecosystem (in snow, canopy interception, soil and litter) controls the exchange of the water and energy between the land surface and the atmosphere. Therefore, measurements of the water stored within these pools are critical for the prediction of e.g. evapotranspiration and groundwater recharge. The detection of cosmic-ray neutron intensity is a novel non-invasive method for the quantification of continuous intermediate-scale soil moisture. The footprint of the cosmic-ray neutron probe is a hemisphere of a few hectometers and subsurface depths of 10-70 cm depending on wetness. The cosmic-ray neutron method offers measurements at a scale between the point-scale measurements and large-scale satellite retrievals. The cosmic-ray neutron intensity is inversely correlated to the hydrogen stored within the footprint. Overall soil moisture represents the largest pool of hydrogen and changes in the soil moisture clearly affect the cosmic-ray neutron signal. However, the neutron intensity is also sensitive to variations of hydrogen in snow, canopy interception and biomass offering the potential to determine water content in such pools from the signal. In this study we tested the potential of determining canopy interception and biomass using cosmic-ray neutron intensity measurements within the framework of the Danish Hydrologic Observatory (HOBE) and the Terrestrial Environmental Observatories (TERENO). Continuous measurements at the ground and the canopy level, along with profile measurements were conducted at towers at forest field sites. Field experiments, including shielding the cosmic-ray neutron probes with cadmium foil (to remove lower-energy neutrons) and measuring reference intensity rates at complete water saturated conditions (on the sea close to the HOBE site), were further conducted to obtain an increased understanding of the physics controlling the cosmic-ray neutron transport and the equipment used

  10. Quantifying the Carbon Intensity of Biomass Energy

    NASA Astrophysics Data System (ADS)

    Hodson, E. L.; Wise, M.; Clarke, L.; McJeon, H.; Mignone, B.

    2012-12-01

    Regulatory agencies at the national and regional level have recognized the importance of quantitative information about greenhouse gas emissions from biomass used in transportation fuels or in electricity generation. For example, in the recently enacted California Low-Carbon Fuel Standard, the California Air Resources Board conducted a comprehensive study to determine an appropriate methodology for setting carbon intensities for biomass-derived transportation fuels. Furthermore, the U.S. Environmental Protection Agency is currently conducting a multi-year review to develop a methodology for estimating biogenic carbon dioxide (CO2) emissions from stationary sources. Our study develops and explores a methodology to compute carbon emission intensities (CIs) per unit of biomass energy, which is a metric that could be used to inform future policy development exercises. To compute CIs for biomass, we use the Global Change Assessment Model (GCAM), which is an integrated assessment model that represents global energy, agriculture, land and physical climate systems with regional, sectoral, and technological detail. The GCAM land use and land cover component includes both managed and unmanaged land cover categories such as food crop production, forest products, and various non-commercial land uses, and it is subdivided into 151 global land regions (wiki.umd.edu/gcam), ten of which are located in the U.S. To illustrate a range of values for different biomass resources, we use GCAM to compute CIs for a variety of biomass crops grown in different land regions of the U.S. We investigate differences in emissions for biomass crops such as switchgrass, miscanthus and willow. Specifically, we use GCAM to compute global carbon emissions from the land use change caused by a marginal increase in the amount of biomass crop grown in a specific model region. Thus, we are able to explore how land use change emissions vary by the type and location of biomass crop grown in the U.S. Direct

  11. Forest biomass for energy: a perspective

    SciTech Connect

    Sajdak, R.L.; Lai, Y.Z.; Mroz, G.D.; Jurgensen, M.F.

    1981-01-01

    Various studies suggest wood could supply to to 10% of the Nation's current energy needs within the next decade. Depending upon the strategies used, eventually it may be possible to supply 20% of our total energy budget. However, the use of wood for energy production must be kept in proper perspective. Wood is not the only product of our forests. These lands play a vital role in providing various social and cultural benefits such as wilderness, outdoor recreation, wildlife, fish, and clean water. Therefore, no single resource or forest use can be examined in isolation from the others. Energy uses will have to be balanced against the growing demand on our forests for lumber, fiber products, and recreational opportunities. This paper analyzes the feasibility and implications of increased utilization of our forests as a source of energy. Consideration will also be given to the production of biomass from intensively cultured plantations as well as the quality of the biomass produced by different management techniques.

  12. Biomass resilience of Neotropical secondary forests

    NASA Astrophysics Data System (ADS)

    Poorter, Lourens; Bongers, Frans; Aide, T. Mitchell; Almeyda Zambrano, Angélica M.; Balvanera, Patricia; Becknell, Justin M.; Boukili, Vanessa; Brancalion, Pedro H. S.; Broadbent, Eben N.; Chazdon, Robin L.; Craven, Dylan; de Almeida-Cortez, Jarcilene S.; Cabral, George A. L.; de Jong, Ben H. J.; Denslow, Julie S.; Dent, Daisy H.; Dewalt, Saara J.; Dupuy, Juan M.; Durán, Sandra M.; Espírito-Santo, Mario M.; Fandino, María C.; César, Ricardo G.; Hall, Jefferson S.; Hernandez-Stefanoni, José Luis; Jakovac, Catarina C.; Junqueira, André B.; Kennard, Deborah; Letcher, Susan G.; Licona, Juan-Carlos; Lohbeck, Madelon; Marín-Spiotta, Erika; Martínez-Ramos, Miguel; Massoca, Paulo; Meave, Jorge A.; Mesquita, Rita; Mora, Francisco; Muñoz, Rodrigo; Muscarella, Robert; Nunes, Yule R. F.; Ochoa-Gaona, Susana; de Oliveira, Alexandre A.; Orihuela-Belmonte, Edith; Peña-Claros, Marielos; Pérez-García, Eduardo A.; Piotto, Daniel; Powers, Jennifer S.; Rodríguez-Velázquez, Jorge; Romero-Pérez, I. Eunice; Ruíz, Jorge; Saldarriaga, Juan G.; Sanchez-Azofeifa, Arturo; Schwartz, Naomi B.; Steininger, Marc K.; Swenson, Nathan G.; Toledo, Marisol; Uriarte, Maria; van Breugel, Michiel; van der Wal, Hans; Veloso, Maria D. M.; Vester, Hans F. M.; Vicentini, Alberto; Vieira, Ima C. G.; Bentos, Tony Vizcarra; Williamson, G. Bruce; Rozendaal, Danaë M. A.

    2016-02-01

    Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between deforestation and forest regrowth has large consequences for the global carbon cycle. However, considerable uncertainty remains about the rate of biomass recovery in secondary forests, and how these rates are influenced by climate, landscape, and prior land use. Here we analyse aboveground biomass recovery during secondary succession in 45 forest sites and about 1,500 forest plots covering the major environmental gradients in the Neotropics. The studied secondary forests are highly productive and resilient. Aboveground biomass recovery after 20 years was on average 122 megagrams per hectare (Mg ha-1), corresponding to a net carbon uptake of 3.05 Mg C ha-1 yr-1, 11 times the uptake rate of old-growth forests. Aboveground biomass stocks took a median time of 66 years to recover to 90% of old-growth values. Aboveground biomass recovery after 20 years varied 11.3-fold (from 20 to 225 Mg ha-1) across sites, and this recovery increased with water availability (higher local rainfall and lower climatic water deficit). We present a biomass recovery map of Latin America, which illustrates geographical and climatic variation in carbon sequestration potential during forest regrowth. The map will support policies to minimize forest loss in areas where biomass resilience is naturally low (such as seasonally dry forest regions) and promote forest regeneration and restoration in humid tropical lowland areas with high biomass resilience.

  13. Biomass resilience of Neotropical secondary forests.

    PubMed

    Poorter, Lourens; Bongers, Frans; Aide, T Mitchell; Almeyda Zambrano, Angélica M; Balvanera, Patricia; Becknell, Justin M; Boukili, Vanessa; Brancalion, Pedro H S; Broadbent, Eben N; Chazdon, Robin L; Craven, Dylan; de Almeida-Cortez, Jarcilene S; Cabral, George A L; de Jong, Ben H J; Denslow, Julie S; Dent, Daisy H; DeWalt, Saara J; Dupuy, Juan M; Durán, Sandra M; Espírito-Santo, Mario M; Fandino, María C; César, Ricardo G; Hall, Jefferson S; Hernandez-Stefanoni, José Luis; Jakovac, Catarina C; Junqueira, André B; Kennard, Deborah; Letcher, Susan G; Licona, Juan-Carlos; Lohbeck, Madelon; Marín-Spiotta, Erika; Martínez-Ramos, Miguel; Massoca, Paulo; Meave, Jorge A; Mesquita, Rita; Mora, Francisco; Muñoz, Rodrigo; Muscarella, Robert; Nunes, Yule R F; Ochoa-Gaona, Susana; de Oliveira, Alexandre A; Orihuela-Belmonte, Edith; Peña-Claros, Marielos; Pérez-García, Eduardo A; Piotto, Daniel; Powers, Jennifer S; Rodríguez-Velázquez, Jorge; Romero-Pérez, I Eunice; Ruíz, Jorge; Saldarriaga, Juan G; Sanchez-Azofeifa, Arturo; Schwartz, Naomi B; Steininger, Marc K; Swenson, Nathan G; Toledo, Marisol; Uriarte, Maria; van Breugel, Michiel; van der Wal, Hans; Veloso, Maria D M; Vester, Hans F M; Vicentini, Alberto; Vieira, Ima C G; Bentos, Tony Vizcarra; Williamson, G Bruce; Rozendaal, Danaë M A

    2016-02-11

    Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between deforestation and forest regrowth has large consequences for the global carbon cycle. However, considerable uncertainty remains about the rate of biomass recovery in secondary forests, and how these rates are influenced by climate, landscape, and prior land use. Here we analyse aboveground biomass recovery during secondary succession in 45 forest sites and about 1,500 forest plots covering the major environmental gradients in the Neotropics. The studied secondary forests are highly productive and resilient. Aboveground biomass recovery after 20 years was on average 122 megagrams per hectare (Mg ha(-1)), corresponding to a net carbon uptake of 3.05 Mg C ha(-1) yr(-1), 11 times the uptake rate of old-growth forests. Aboveground biomass stocks took a median time of 66 years to recover to 90% of old-growth values. Aboveground biomass recovery after 20 years varied 11.3-fold (from 20 to 225 Mg ha(-1)) across sites, and this recovery increased with water availability (higher local rainfall and lower climatic water deficit). We present a biomass recovery map of Latin America, which illustrates geographical and climatic variation in carbon sequestration potential during forest regrowth. The map will support policies to minimize forest loss in areas where biomass resilience is naturally low (such as seasonally dry forest regions) and promote forest regeneration and restoration in humid tropical lowland areas with high biomass resilience.

  14. Secondary Forest Age and Tropical Forest Biomass Estimation Using TM

    NASA Technical Reports Server (NTRS)

    Nelson, R. F.; Kimes, D. S.; Salas, W. A.; Routhier, M.

    1999-01-01

    The age of secondary forests in the Amazon will become more critical with respect to the estimation of biomass and carbon budgets as tropical forest conversion continues. Multitemporal Thematic Mapper data were used to develop land cover histories for a 33,000 Square kM area near Ariquemes, Rondonia over a 7 year period from 1989-1995. The age of the secondary forest, a surrogate for the amount of biomass (or carbon) stored above-ground, was found to be unimportant in terms of biomass budget error rates in a forested TM scene which had undergone a 20% conversion to nonforest/agricultural cover types. In such a situation, the 80% of the scene still covered by primary forest accounted for over 98% of the scene biomass. The difference between secondary forest biomass estimates developed with and without age information were inconsequential relative to the estimate of biomass for the entire scene. However, in futuristic scenarios where all of the primary forest has been converted to agriculture and secondary forest (55% and 42% respectively), the ability to age secondary forest becomes critical. Depending on biomass accumulation rate assumptions, scene biomass budget errors on the order of -10% to +30% are likely if the age of the secondary forests are not taken into account. Single-date TM imagery cannot be used to accurately age secondary forests into single-year classes. A neural network utilizing TM band 2 and three TM spectral-texture measures (bands 3 and 5) predicted secondary forest age over a range of 0-7 years with an RMSE of 1.59 years and an R(Squared) (sub actual vs predicted) = 0.37. A proposal is made, based on a literature review, to use satellite imagery to identify general secondary forest age groups which, within group, exhibit relatively constant biomass accumulation rates.

  15. [Estimation of Shenyang urban forest green biomass].

    PubMed

    Liu, Chang-fu; He, Xing-yuan; Chen, Wei; Zhao, Gui-ling; Xu, Wen-duo

    2007-06-01

    Based on ARC/GIS and by using the method of "planar biomass estimation", the green biomass (GB) of Shenyang urban forests was measured. The results demonstrated that the GB per unit area was the highest (3.86 m2.m(-2)) in landscape and relaxation forest, and the lowest (2.27 m2.m(-2)) in ecological and public welfare forest. The GB per unit area in urban forest distribution area was 2.99 m2.m(-2), and that of the whole Shenyang urban area was 0.25 m2.m(-2). The total GB of Shenyang urban forests was about 1.13 x 10(8) m2, among which, subordinated forest, ecological and public welfare forest, landscape and relaxation forest, road forest, and production and management forest accounted for 36.64% , 23.99% , 19.38% , 16.20% and 3.79%, with their GB being 4. 15 x 10(7), 2.72 x 10(7), 2.20 x 10(7), 1.84 x 10(7) and 0.43 x 10(7) m2, respectively. The precision of the method "planar biomass estimation" was 91.81% (alpha = 0.05) by credit test.

  16. Rates of biomass accumulation of North Carolina Piedmont forests

    SciTech Connect

    Peet, R.K.; Council, O.P.

    1980-01-01

    Recent work by Sharp et al. on the primary production of North Carolina vegetation has suggested that the average natural forest in North Carolina is unproductive relative to its potential as intensively managed forest, the difference being roughly 300%. This variation could be attributable to patterns of forest recovery after disturbance, to management practices, or even to species composition. These and other alternative hypotheses need to be tested in a careful and objective manner. The primary objectives of the present research project were twofold: (1) to use dimension analysis methods to develop a set of regression equations useful for evaluating the productivity (rate of solar energy fixation) and biomass (stored energy) of North Carolina piedmont forests; (2) to use the resulting equations to document patterns in and rates of change of forest production and biomass during forest recovery from disturbance. The first objective was divided into two component parts. First, the regression equations were developed. Second, the caloric content of trees was studied so as to allow conversion from biomass units (Kg/m/sup 2/) to energy units (Kcal/m/sup 2/). Section 2 of this report outlines the dimension analysis procedure, presents the resulting equations, and explains their use. The portion of the project assessing the caloric content of trees is presented in Section 3. The results of our second objective, the examination of changes in forest biomass and production, are presented in Section 4.

  17. The impact of intensive forest management on carbon stores in forest ecosystems

    SciTech Connect

    Krankina, O.N.; Harmon, M.E. . Dept. of Forest Science)

    1994-06-01

    The expansion of intensive management of forest resources for timber production with the human population growth may have a profound effect on the role forests play in the global carbon cycle. First, the transition from old-growth to intensively managed second-growth forest with short rotations entails major long-term ecosystems changes including the reduction of total woody biomass. Although the biomass of living trees can be restored within a relatively short period of time, dead wood biomass takes considerably longer to reach pre-harvest levels; therefore commonly used rotations are too short for the latter part of ecosystem to recover fully. As dead trees account for 14--18% of the total woody biomass stores in a natural forest, a considerable amount of carbon can be released if this material is not replaced. Second, economically efficient, intensive forest management systems that include commercial thinning and wood salvage can further reduce the total biomass loading of second-growth forests. Long-term study of live and dead wood in thinning trials in the Pacific Northwest and in northwestern Russia suggest that intensive practices can reduce total woody biomass averaged over rotation to 10--25% that found in a natural old-growth forest. Therefore intensive forest management practices may maximize the supply of raw materials, but they may also generate a major carbon flux into the atmosphere. This flux may be significant despite the fact the land-use type remains the same. Effect of intensive forest management practices should be included in future carbon budgets and in developing forest management strategies aimed at increasing carbon storage in forest ecosystems.

  18. Forest classification and impact of BIOMASS resolution on forest area and aboveground biomass estimation

    NASA Astrophysics Data System (ADS)

    Schlund, Michael; Scipal, Klaus; Davidson, Malcolm W. J.

    2017-04-01

    The European Space Agency (ESA) is currently implementing the BIOMASS mission as 7th Earth Explorer satellite. BIOMASS will provide for the first time global forest aboveground biomass estimates based on P-band synthetic aperture radar (SAR) imagery. This paper addresses an often overlooked element of the data processing chain required to ensure reliable and accurate forest biomass estimates: accurate identification of forest areas ahead of the inversion of radar data into forest biomass estimates. The use of the P-band data from BIOMASS itself for the classification into forest and non-forest land cover types is assessed in this paper. For airborne data in tropical, hemi-boreal and boreal forests we demonstrate that classification accuracies from 90 up to 97% can be achieved using radar backscatter and phase information. However, spaceborne data will have a lower resolution and higher noise level compared to airborne data and a higher probability of mixed pixels containing multiple land cover types. Therefore, airborne data was reduced to 50 m, 100 m and 200 m resolution. The analysis revealed that about 50-60% of the area within the resolution level must be covered by forest to classify a pixel with higher probability as forest compared to non-forest. This results in forest omission and commission leading to similar forest area estimation over all resolutions. However, the forest omission resulted in a biased underestimated biomass, which was not equaled by the forest commission. The results underline the necessity of a highly accurate pre-classification of SAR data for an accurate unbiased aboveground biomass estimation.

  19. Polyhydroxyalkanoate copolymers from forest biomass.

    PubMed

    Keenan, Thomas M; Nakas, James P; Tanenbaum, Stuart W

    2006-07-01

    The potential for the use of woody biomass in poly-beta-hydroxyalkanoate (PHA) biosynthesis is reviewed. Based on previously cited work indicating incorporation of xylose or levulinic acid (LA) into PHAs by several bacterial strains, we have initiated a study for exploring bioconversion of forest resources to technically relevant copolymers. Initially, PHA was synthesized in shake-flask cultures of Burkholderia cepacia grown on 2.2% (w/v) xylose, periodically amended with varying concentrations of levulinic acid [0.07-0.67% (w/v)]. Yields of poly(beta-hydroxybutyrate-co-beta-hydroxyvalerate) [P(3HB-co-3HV)] from 1.3 to 4.2 g/l were obtained and could be modulated to contain from 1.0 to 61 mol% 3-hydroxyvalerate (3HV), as determined by 1H and 13C NMR analyses. No evidence for either the 3HB or 4HV monomers was found. Characterization of these P(3HB-co-3HV) samples, which ranged in molecular mass (viscometric, Mv) from 511-919 kDa, by differential scanning calorimetry and thermogravimetric analyses (TGA) provided data which were in agreement for previously reported P(3HB-co-3HV) copolymers. For these samples, it was noted that melting temperature (Tm) and glass transition temperature (Tg) decreased as a function of 3HVcontent, with Tm demonstrating a pseudoeutectic profile as a function of mol% 3HV content. In order to extend these findings to the use of hemicellulosic process streams as an inexpensive carbon source, a detoxification procedure involving sequential overliming and activated charcoal treatments was developed. Two such detoxified process hydrolysates (NREL CF: aspen and CESF: maple) were each fermented with appropriate LA supplementation. For the NREL CF hydrolysate-based cultures amended with 0.25-0.5% LA, P(3HB-co-3HV) yields, PHA contents (PHA as percent of dry biomass), and mol% 3HV compositions of 2.0 g/l, 40% (w/w), and 16-52 mol% were obtained, respectively. Similarly, the CESF hydrolysate-based shake-flask cultures yielded 1.6 g/l PHA, 39% (w

  20. Validating Community-Led Forest Biomass Assessments

    PubMed Central

    Venter, Michelle; Venter, Oscar; Edwards, Will; Bird, Michael I.

    2015-01-01

    The lack of capacity to monitor forest carbon stocks in developing countries is undermining global efforts to reduce carbon emissions. Involving local people in monitoring forest carbon stocks could potentially address this capacity gap. This study conducts a complete expert remeasurement of community-led biomass inventories in remote tropical forests of Papua New Guinea. By fully remeasuring and isolating the effects of 4,481 field measurements, we demonstrate that programmes employing local people (non-experts) can produce forest monitoring data as reliable as those produced by scientists (experts). Overall, non-experts reported lower biomass estimates by an average of 9.1%, equivalent to 55.2 fewer tonnes of biomass ha-1, which could have important financial implications for communities. However, there were no significant differences between forest biomass estimates of expert and non-expert, nor were there significant differences in some of the components used to calculate these estimates, such as tree diameter at breast height (DBH), tree counts and plot surface area, but were significant differences between tree heights. At the landscape level, the greatest biomass discrepancies resulted from height measurements (41%) and, unexpectedly, a few large missing trees contributing to a third of the overall discrepancies. We show that 85% of the biomass discrepancies at the tree level were caused by measurement taken on large trees (DBH ≥50cm), even though they consisted of only 14% of the stems. We demonstrate that programmes that engage local people can provide high-quality forest carbon data that could help overcome barriers to reducing forest carbon emissions in developing countries. Nonetheless, community-based monitoring programmes should prioritise reducing errors in the field that lead to the most important discrepancies, notably; overcoming challenges to accurately measure large trees. PMID:26126186

  1. Increasing biomass in Amazonian forest plots.

    PubMed Central

    Baker, Timothy R; Phillips, Oliver L; Malhi, Yadvinder; Almeida, Samuel; Arroyo, Luzmila; Di Fiore, Anthony; Erwin, Terry; Higuchi, Niro; Killeen, Timothy J; Laurance, Susan G; Laurance, William F; Lewis, Simon L; Monteagudo, Abel; Neill, David A; Vargas, Percy Núñez; Pitman, Nigel C A; Silva, J Natalino M; Martínez, Rodolfo Vásquez

    2004-01-01

    A previous study by Phillips et al. of changes in the biomass of permanent sample plots in Amazonian forests was used to infer the presence of a regional carbon sink. However, these results generated a vigorous debate about sampling and methodological issues. Therefore we present a new analysis of biomass change in old-growth Amazonian forest plots using updated inventory data. We find that across 59 sites, the above-ground dry biomass in trees that are more than 10 cm in diameter (AGB) has increased since plot establishment by 1.22 +/- 0.43 Mg per hectare per year (ha(-1) yr(-1), where 1 ha = 10(4) m2), or 0.98 +/- 0.38 Mg ha(-1) yr(-1) if individual plot values are weighted by the number of hectare years of monitoring. This significant increase is neither confounded by spatial or temporal variation in wood specific gravity, nor dependent on the allometric equation used to estimate AGB. The conclusion is also robust to uncertainty about diameter measurements for problematic trees: for 34 plots in western Amazon forests a significant increase in AGB is found even with a conservative assumption of zero growth for all trees where diameter measurements were made using optical methods and/or growth rates needed to be estimated following fieldwork. Overall, our results suggest a slightly greater rate of net stand-level change than was reported by Phillips et al. Considering the spatial and temporal scale of sampling and associated studies showing increases in forest growth and stem turnover, the results presented here suggest that the total biomass of these plots has on average increased and that there has been a regional-scale carbon sink in old-growth Amazonian forests during the previous two decades. PMID:15212090

  2. Biomass and nutrient distributions in central Oregon second-growth ponderosa pine ecosystems. Forest Service research paper

    SciTech Connect

    Little, S.N.; Shainsky, L.J.

    1995-03-01

    We investigated the distributioin of biomass and nurtrients in second-growth ponderosa pine (Pinus ponderosa Dougl. ex Laws.) ecosystems in central Oregon. Destructive sampling of aboveground and belowground tree biomass was carried out at six sites in the Deschutes National Forest; three of these sites also were intensively sampled for biomass and nutrient concentrations of the soil, forest floor, residue, and shrub components. Tree biomass equations were developed that related component biomass to diameter at breast height and total tree height.

  3. MODIS Based Estimation of Forest Aboveground Biomass in China.

    PubMed

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

    2015-01-01

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

  4. MODIS Based Estimation of Forest Aboveground Biomass in China

    PubMed Central

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

    2015-01-01

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

  5. Remote Characterization of Biomass Measurements: Case Study of Mangrove Forests

    NASA Technical Reports Server (NTRS)

    Fatoyinbo, Temilola E.

    2010-01-01

    Accurately quantifying forest biomass is of crucial importance for climate change studies. By quantifying the amount of above and below ground biomass and consequently carbon stored in forest ecosystems, we are able to derive estimates of carbon sequestration, emission and storage and help close the carbon budget. Mangrove forests, in addition to providing habitat and nursery grounds for over 1300 animal species, are also an important sink of biomass. Although they only constitute about 3% of the total forested area globally, their carbon storage capacity -- in forested biomass and soil carbon -- is greater than that of tropical forests (Lucas et al, 2007). In addition, the amount of mangrove carbon -- in the form of litter and leaves exported into offshore areas is immense, resulting in over 10% of the ocean's dissolved organic carbon originating from mangroves (Dittmar et al, 2006) The measurement of forest above ground biomass is carried out on two major scales: on the plot scale, biomass can be measured using field measurements through allometric equation derivation and measurements of forest plots. On the larger scale, the field data are used to calibrate remotely sensed data to obtain stand-wide or even regional estimates of biomass. Currently, biomass can be calculated using average stand biomass values and optical data, such as aerial photography or satellite images (Landsat, Modis, Ikonos, SPOT, etc.). More recent studies have concentrated on deriving forest biomass values using radar (JERS, SIR-C, SRTM, Airsar) and/or lidar (ICEsat/GLAS, LVIS) active remote sensing to retrieve more accurate and detailed measurements of forest biomass. The implementation of a generation of new active sensors (UAVSar, DesdynI, Alos/Palsar, TerraX) has prompted the development of new tecm'liques of biomass estimation that use the combination of multiple sensors and datasets, to quantify past, current and future biomass stocks. Focusing on mangrove forest biomass estimation

  6. Linking state-and-transition simulation and timber supply models for forest biomass production scenarios

    USGS Publications Warehouse

    Costanza, Jennifer; Abt, Robert C.; McKerrow, Alexa; Collazo, Jaime

    2015-01-01

    We linked state-and-transition simulation models (STSMs) with an economics-based timber supply model to examine landscape dynamics in North Carolina through 2050 for three scenarios of forest biomass production. Forest biomass could be an important source of renewable energy in the future, but there is currently much uncertainty about how biomass production would impact landscapes. In the southeastern US, if forests become important sources of biomass for bioenergy, we expect increased land-use change and forest management. STSMs are ideal for simulating these landscape changes, but the amounts of change will depend on drivers such as timber prices and demand for forest land, which are best captured with forest economic models. We first developed state-and-transition model pathways in the ST-Sim software platform for 49 vegetation and land-use types that incorporated each expected type of landscape change. Next, for the three biomass production scenarios, the SubRegional Timber Supply Model (SRTS) was used to determine the annual areas of thinning and harvest in five broad forest types, as well as annual areas converted among those forest types, agricultural, and urban lands. The SRTS output was used to define area targets for STSMs in ST-Sim under two scenarios of biomass production and one baseline, business-as-usual scenario. We show that ST-Sim output matched SRTS targets in most cases. Landscape dynamics results indicate that, compared with the baseline scenario, forest biomass production leads to more forest and, specifically, more intensively managed forest on the landscape by 2050. Thus, the STSMs, informed by forest economics models, provide important information about potential landscape effects of bioenergy production.

  7. Demographic controls of aboveground forest biomass across North America.

    PubMed

    Vanderwel, Mark C; Zeng, Hongcheng; Caspersen, John P; Kunstler, Georges; Lichstein, Jeremy W

    2016-04-01

    Ecologists have limited understanding of how geographic variation in forest biomass arises from differences in growth and mortality at continental to global scales. Using forest inventories from across North America, we partitioned continental-scale variation in biomass growth and mortality rates of 49 tree species groups into (1) species-independent spatial effects and (2) inherent differences in demographic performance among species. Spatial factors that were separable from species composition explained 83% and 51% of the respective variation in growth and mortality. Moderate additional variation in mortality (26%) was attributable to differences in species composition. Age-dependent biomass models showed that variation in forest biomass can be explained primarily by spatial gradients in growth that were unrelated to species composition. Species-dependent patterns of mortality explained additional variation in biomass, with forests supporting less biomass when dominated by species that are highly susceptible to competition (e.g. Populus spp.) or to biotic disturbances (e.g. Abies balsamea).

  8. ROOT BIOMASS ALLOCATION IN THE WORLD'S UPLAND FORESTS

    EPA Science Inventory

    Because the world's forests play a major role in regulating nutrient and carbon cycles, there is much interest in estimating their biomass. Estimates of aboveground biomass based on well-established methods are relatively abundant; estimates of root biomass based on standard meth...

  9. The relative contributions of forest growth and areal expansion to forest biomass carbon

    NASA Astrophysics Data System (ADS)

    Li, P.; Zhu, J.; Hu, H.; Guo, Z.; Pan, Y.; Birdsey, R.; Fang, J.

    2016-01-01

    Forests play a leading role in regional and global terrestrial carbon (C) cycles. Changes in C sequestration within forests can be attributed to areal expansion (increase in forest area) and forest growth (increase in biomass density). Detailed assessment of the relative contributions of areal expansion and forest growth to C sinks is crucial to reveal the mechanisms that control forest C sinks and it is helpful for developing sustainable forest management policies in the face of climate change. Using the Forest Identity concept and forest inventory data, this study quantified the spatial and temporal changes in the relative contributions of forest areal expansion and increased biomass growth to China's forest biomass C sinks from 1977 to 2008. Over the last 30 years, the areal expansion of forests has been a larger contributor to C sinks than forest growth for planted forests in China (62.2 % vs. 37.8 %). However, for natural forests, forest growth has made a larger contribution than areal expansion (60.4 % vs. 39.6 %). For all forests (planted and natural forests), growth in area and density has contributed equally to the total C sinks of forest biomass in China (50.4 % vs. 49.6 %).The relative contribution of forest growth of planted forests showed an increasing trend from an initial 25.3 % to 61.0 % in the later period of 1998 to 2003, but for natural forests, the relative contributions were variable without clear trends, owing to the drastic changes in forest area and biomass density over the last 30 years. Our findings suggest that afforestation will continue to increase the C sink of China's forests in the future, subject to sustainable forest growth after the establishment of plantations.

  10. EXPLAINING FOREST COMPOSITION AND BIOMASS ACROSS MULTIPLE BIOGEOGRAPHIC REGIONS

    EPA Science Inventory

    Current scientific concerns regarding the impacts of global change include the responses of forest composition and biomass to rapid changes in climate, and forest gap models, have often been used to address this issue. These models reflect the concept that forest composition and...

  11. Changes in forest biomass and linkage to climate and forest disturbances over Northeastern China.

    PubMed

    Zhang, Yuzhen; Liang, Shunlin

    2014-08-01

    The forests of northeastern China store nearly half of the country's total biomass carbon stocks. In this study, we investigated the changes in forest biomass by using satellite observations and found that a significant increase in forest biomass took place between 2001 and 2010. To determine the possible reasons for this change, several statistical methods were used to analyze the correlations between forest biomass dynamics and forest disturbances (i.e. fires, insect damage, logging, and afforestation and reforestation), climatic factors, and forest development. Results showed that forest development was the most important contributor to the increasing trend of forest biomass from 2001 to 2010, and climate controls were the secondary important factor. Among the four types of forest disturbance considered in this study, forest recovery from fires, and afforestation and reforestation during the past few decades played an important role in short-term biomass dynamics. This study provided observational evidence and valuable information for the relationships between forest biomass and climate as well as forest disturbances.

  12. Correlating radar backscatter with components of biomass in loblolly pine forests

    SciTech Connect

    Kasischke, E.S.; Bourgeau-Chavez, L.L.; Christensen, N.L. Jr.

    1995-05-01

    A multifrequency, multipolarization airborne SAR data set was utilized to examine the relationship between radar backscatter and the aboveground biomass in loblolly pine forests. This data set was also used to examine the potential of SAR to estimate aboveground biomass in these forests. The total aboveground biomass in the test stands used in this study ranged from <1--50 kg m{sup {minus}2}. Not only was total aboveground biomass considered, but the biomass of the tree boles, branches, and needles/leaves. Significant correlations were found in all three frequencies of radar imagery used in this study. At P- and L-bands, the greatest sensitivity to change in biomass occurred in the HH and VH polarized channels, while at C-band, the greatest sensitivity was in the VH polarized channel. The results of the correlation analyses support modeling studies which show the dominant scattering mechanisms from these pines should be double-bounce, ground-trunk scattering and canopy volume scattering. To produce equations to estimate biomass, a stepwise, multiple-linear regression approach was used, using all the radar channels as independent variables, and the log of the biomass components as the dependent variables. The authors conclude from this analysis that the image intensity signatures recorded on SAR imagery have the potential to be used as a basis for estimation of aboveground biomass in pine forests, for total stand biomass levels up to 35--40 kg m{sup {minus}2}.

  13. Radar Backscatter Saturation with Forest Biomass: Facts and Myths

    NASA Astrophysics Data System (ADS)

    Saatchi, S. S.

    2012-12-01

    In recent years, climate change policies and scientific research created a widespread interest in quantify the carbon stock and changes of global forests extending from forest patches to national and regional scales. However, because of the large spatial extent of forests, their heterogeneity from structural and species diversity causing meters to kilometer scales variations, their complex dynamics causing landscape scale differences in changes of biomass, and their continues degradation from human activities, the quantification of forest biomass from conventional inventory data alone has become a major challenge. Remote sensing techniques with Lidar and Radar are considered to be the most efficient way of estimating forest biomass at large scales and with uncertainty comparable to estimation from inventory plots. Radar backscatter and interferometric based estimation of forest biomass has been studied extensively and considered as dedicated spaceborne options of monitoring and quantifying forest biomass. However, the literature on the radar-based estimation techniques of biomass has been misleading in defining the sensitivity and lack of sensitivity, so called saturation effect of radar measurements. In this paper, I provide results from a combination of observations and model simulations to demonstrate the physical nature of the loss of sensitivity of radar backscatter to biomass, examine the biophysical that impact the sensitivity, extend the results to other radar measurements including polarimetric and interferometric modes.

  14. Forest biomass carbon stocks and variation in Tibet's carbon-dense forests from 2001 to 2050.

    PubMed

    Sun, Xiangyang; Wang, Genxu; Huang, Mei; Chang, Ruiying; Ran, Fei

    2016-10-05

    Tibet's forests, in contrast to China's other forests, are characterized by primary forests, high carbon (C) density and less anthropogenic disturbance, and they function as an important carbon pool in China. Using the biomass C density data from 413 forest inventory sites and a spatial forest age map, we developed an allometric equation for the forest biomass C density and forest age to assess the spatial biomass C stocks and variation in Tibet's forests from 2001 to 2050. The results indicated that the forest biomass C stock would increase from 831.1 Tg C in 2001 to 969.4 Tg C in 2050, with a net C gain of 3.6 Tg C yr(-1) between 2001 and 2010 and a decrease of 1.9 Tg C yr(-1) between 2040 and 2050. Carbon tends to allocate more in the roots of fir forests and less in the roots of spruce and pine forests with increasing stand age. The increase of the biomass carbon pool does not promote significant augmentation of the soil carbon pool. Our findings suggest that Tibet's mature forests will remain a persistent C sink until 2050. However, afforestation or reforestation, especially with the larger carbon sink potential forest types, such as fir and spruce, should be carried out to maintain the high C sink capacity.

  15. Waveform LiDAR across forest biomass gradients

    NASA Astrophysics Data System (ADS)

    Montesano, P. M.; Nelson, R. F.; Dubayah, R.; Sun, G.; Ranson, J.

    2011-12-01

    Detailed information on the quantity and distribution of aboveground biomass (AGB) is needed to understand how it varies across space and changes over time. Waveform LiDAR data is routinely used to derive the heights of scattering elements in each illuminated footprint, and the vertical structure of vegetation is related to AGB. Changes in LiDAR waveforms across vegetation structure gradients can demonstrate instrument sensitivity to land cover transitions. A close examination of LiDAR waveforms in footprints across a forest gradient can provide new insight into the relationship of vegetation structure and forest AGB. In this study we use field measurements of individual trees within Laser Vegetation Imaging Sensor (LVIS) footprints along transects crossing forest to non-forest gradients to examine changes in LVIS waveform characteristics at sites with low (< 50Mg/ha) AGB. We relate field AGB measurements to original and adjusted LVIS waveforms to detect the forest AGB interval along a forest - non-forest transition in which the LVIS waveform lose the ability to discern differences in AGB. Our results help identify the lower end the forest biomass range that a ~20m footprint waveform LiDAR can detect, which can help infer accumulation of biomass after disturbances and during forest expansion, and which can guide the use of LiDAR within a multi-sensor fusion biomass mapping approach.

  16. The Biomass mission: a step forward in quantifying forest biomass and structure

    NASA Astrophysics Data System (ADS)

    LE Toan, T.

    2015-12-01

    The primary aim of the ESA BIOMASS mission is to determine, for the first time and in a consistent manner, the global distribution of above-ground forest biomass (AGB) in order to provide greatly improved quantification of the size and distribution of the terrestrial carbon pool, and improved estimates of terrestrial carbon fluxes. Specifically, BIOMASS will measure forest carbon stock, as well as forest height, from data provided by a single satellite giving a biomass map covering tropical, temperate and boreal forests at a resolution of around 200 m every 6 months throughout the five years of the mission. BIOMASS will use a long wavelength SAR (P-band) providing three mutually supporting measurement techniques, namely polarimetric SAR (PolSAR), polarimetric interferometric SAR (PolInSAR) and tomographic SAR (TomoSAR). The combination of these techniques will significantly reduce the uncertainties in biomass retrievals by yielding complementary information on biomass properties. Horizontal mapping: For a forest canopy, the P-band radar waves penetrate deep into the canopy, and their interaction with the structure of the forest will be exploited to map above ground biomass (AGB), as demonstrated from airborne data for temperate, boreal forests and tropical forest. Height mapping: By repeat revisits to the same location, the PolInSAR measurements will be used to estimate the height of scattering in the forest canopy. The long wavelength used by BIOMASS is crucial for the temporal coherence to be preserved over much longer timescales than at L-band, for example. 3D mapping: The P-band frequency used by BIOMASS is low enough to ensure penetration through the entire canopy, even in dense tropical forests. As a consequence, resolution of the vertical structure of the forest will be possible using tomographic methods from the multi-baseline acquisitions. This is the concept of SAR tomography, which will be implemented in the BIOMASS mission. The improvement in the

  17. 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.

  18. Disturbance-induced reduction of biomass carbon sinks of China’s forests in recent years

    NASA Astrophysics Data System (ADS)

    Zhang, Chunhua; Ju, Weimin; Chen, Jing M.; Wang, Xiqun; Yang, Lin; Zheng, Guang

    2015-11-01

    Forests play a critical role in mitigating climate change because of their high carbon storage and productivity. China has experienced a pronounced increase in forest area resulting from afforestation and reforestation activities since the 1970s. However, few comprehensive analyses have been made to assess the recent dynamics of biomass carbon sinks in China’s forests. This study refined biomass carbon sinks of China’s forests based on eight forest inventories from 1973 to 2013. These sinks increased from 25.0 to 166.5 Tg C yr-1 between 1973 and 2008, and then decreased to 130.9 Tg C yr-1 for the period of 2009-2013 because the increases in forest area and biomass carbon density became slower. About 7% and 93% of this sink reduction occurred in planted and natural forests. The carbon sinks for young, middle-aged and premature forests decreased by 27.3, 27.0, and 7.6 Tg C yr-1, respectively. 42% of this decrease was offset by mature and overmature forests. During 2009-2013, forest biomass carbon sinks decreased in all regions but the north and northwest regions. The drivers for changes of forest biomass sinks differ spatially. More intensive harvest of young and middle-aged forests and snow damage were the major drivers for the decreases of biomass carbon sinks in the east (8.0 Tg C yr-1) and south (19.8 Tg C yr-1) regions. The carbon sink reduction in the southwest region (16.7 Tg C yr-1) was mainly caused by increased timber harvesting and natural disturbances, such as droughts in Yunnan province, snow damage in Guizhou province and forest fires in Sichuan province. In the northeast region, the sink reduction occurred mainly in Heilongjiang province (7.9 Tg C yr-1) and was caused dominantly by the combined effects of diseases, windthrow and droughts. The carbon sink increase was primarily attributed to forest growth and decreased deforestation in the north (10.0 Tg C yr-1) and northwest (2.3 Tg C yr-1) regions.

  19. Biomass Accumulation Rates of Amazonian Secondary Forest and Biomass of Old-Growth Forests from Landsat Time Series and GLAS

    NASA Astrophysics Data System (ADS)

    Helmer, E.; Lefsky, M. A.; Roberts, D.

    2009-12-01

    We estimate the age of humid lowland tropical forests in Rondônia, Brazil, from a somewhat densely spaced time series of Landsat images (1975-2003) with an automated procedure, the Threshold Age Mapping Algorithm (TAMA), first described here. We then estimate a landscape-level rate of aboveground woody biomass accumulation of secondary forest by combining forest age mapping with biomass estimates from the Geoscience Laser Altimeter System (GLAS). Though highly variable, the estimated average biomass accumulation rate of 8.4 Mg ha-1 yr-1 agrees well with ground-based studies for young secondary forests in the region. In isolating the lowland forests, we map land cover and general types of old-growth forests with decision tree classification of Landsat imagery and elevation data. We then estimate aboveground live biomass for seven classes of old-growth forest. TAMA is simple, fast, and self-calibrating. By not using between-date band or index differences or trends, it requires neither image normalization nor atmospheric correction. In addition, it uses an approach to map forest cover for the self-calibrations that is novel to forest mapping with satellite imagery; it maps humid secondary forest that is difficult to distinguish from old-growth forest in single-date imagery; it does not assume that forest age equals time since disturbance; and it incorporates Landsat Multispectral Scanner (MSS) imagery. Variations on the work that we present here can be applied to other forested landscapes. Applications that use image time series will be helped by the free distribution of coregistered Landsat imagery, which began in December 2008, and of the Ice Cloud and land Elevation Satellite (ICESat) Vegetation Product, which simplifies the use of GLAS data. Finally, we demonstrate here for the first time how the optical imagery of fine spatial resolution that is viewable on Google Earth provides a new source of reference data for remote sensing applications related to land cover

  20. 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

  1. Simulations of Forest Structure and Biomass across Russia for Biomass Estimation under a Changing Climate.

    NASA Astrophysics Data System (ADS)

    Shugart, H. H., Jr.; Shuman, J. K.

    2014-12-01

    An important innovation in understanding the interactions among physical of forests and measurement of forest state is the potential deployment of active (RADAR and LiDAR) satellite reconnaissance systems. We investigate the potential gain in predictive capability of structural measures determined by these instruments. Observations and model results have identified climate change as a driver of structural and compositional change in forest of Russia, which may affect climate patterns beyond the region. Using an individual-tree-based model (UVAFME) for forests at 31,000+ grid points of a 22 km×22 km grid across Russia, we inspected the relationships between above-ground biomass and structural measures including maximum tree height and Lorey's height (average height for each tree weighted by basal area). At each of the grid points 200 independent 0.1hectare plots were simulated for 100 years using two climate change scenarios following a 500-year spin-up to produce a mature forest. Other simulations project the change of a forest-landscape mosaic with equal proportions of 0, 25, 50, 75 and 100 year-old stands to mimic a heterogeneous landscape mosaic typical of reoccurring wildfires. Qualitatively, maximum height and Lorey's height seem particularly useful in detecting forest change in the vicinity of forest transitions with other ecosystems. Quantitatively, maximum height and Lorey's height account for a large component of the variability in forest biomass. Results of exponential regression between height measurements and biomass show that r2 values can exceed 0.75. Lorey's height is more capable in this regard. The relationship between these measures of height and biomass can be improved with classification of forests into types. For example, Russian forest dominated by the tall, large diameter pines (Pinus koraiensis, P. sibirica, P. sylvestris) can have exceptional biomass compared to other forests across Russia, and produced biomass and height values higher

  2. Forest Biomass Mapping From Lidar and Radar Synergies

    NASA Technical Reports Server (NTRS)

    Sun, Guoqing; Ranson, K. Jon; Guo, Z.; Zhang, Z.; Montesano, P.; Kimes, D.

    2011-01-01

    The use of lidar and radar instruments to measure forest structure attributes such as height and biomass at global scales is being considered for a future Earth Observation satellite mission, DESDynI (Deformation, Ecosystem Structure, and Dynamics of Ice). Large footprint lidar makes a direct measurement of the heights of scatterers in the illuminated footprint and can yield accurate information about the vertical profile of the canopy within lidar footprint samples. Synthetic Aperture Radar (SAR) is known to sense the canopy volume, especially at longer wavelengths and provides image data. Methods for biomass mapping by a combination of lidar sampling and radar mapping need to be developed. In this study, several issues in this respect were investigated using aircraft borne lidar and SAR data in Howland, Maine, USA. The stepwise regression selected the height indices rh50 and rh75 of the Laser Vegetation Imaging Sensor (LVIS) data for predicting field measured biomass with a R(exp 2) of 0.71 and RMSE of 31.33 Mg/ha. The above-ground biomass map generated from this regression model was considered to represent the true biomass of the area and used as a reference map since no better biomass map exists for the area. Random samples were taken from the biomass map and the correlation between the sampled biomass and co-located SAR signature was studied. The best models were used to extend the biomass from lidar samples into all forested areas in the study area, which mimics a procedure that could be used for the future DESDYnI Mission. It was found that depending on the data types used (quad-pol or dual-pol) the SAR data can predict the lidar biomass samples with R2 of 0.63-0.71, RMSE of 32.0-28.2 Mg/ha up to biomass levels of 200-250 Mg/ha. The mean biomass of the study area calculated from the biomass maps generated by lidar- SAR synergy 63 was within 10% of the reference biomass map derived from LVIS data. The results from this study are preliminary, but do show the

  3. Bringing Together Users and Developers of Forest Biomass Maps

    NASA Technical Reports Server (NTRS)

    Brown, Molly E.; Macauley, Molly

    2011-01-01

    Forests store carbon and thus represent important sinks for atmospheric carbon dioxide. Reducing uncertainty in current estimates of the amount of carbon in standing forests will improve precision of estimates of anthropogenic contributions to carbon dioxide in the atmosphere due to deforestation. Although satellite remote sensing has long been an important tool for mapping land cover, until recently aboveground forest biomass estimates have relied mostly on systematic ground sampling of forests. In alignment with fiscal year 2010 congressional direction, NASA has initiated work toward a carbon monitoring system (CMS) that includes both maps of forest biomass and total carbon flux estimates. A goal of the project is to ensure that the products are useful to a wide community of scientists, managers, and policy makers, as well as to carbon cycle scientists. Understanding the needs and requirements of these data users is helpful not just to the NASA CMS program but also to the entire community working on carbon-related activities. To that end, this meeting brought together a small group of natural resource managers and policy makers who use information on forests in their work with NASA scientists who are working to create aboveground forest biomass maps. These maps, derived from combining remote sensing and ground plots, aim to be more accurate than current inventory approaches when applied at local and regional scales.

  4. Dependence of radar backscatter on coniferous forest biomass

    SciTech Connect

    Dobson, M.C.; Ulaby, F.T. ); LeToan, T.; Beaudoin, A. ); Kasischke, E.S. ); Christensen, N. )

    1992-03-01

    This paper discusses two independent experimental efforts which have examined the dependence of radar backscatter on aboveground biomass of mono specie conifer forests using polarimetric airborne SAR data at P-, L- and C-bands. Plantations of maritime pines near Landes, France range in age from 8 to 46 years with aboveground biomass between 5 and 105 tons/ha. Loblolly pine stands established on abandoned agricultural fields near Duke, NC range in age from 4 to 90 years and extend the range of aboveground biomass to 560 tons/ha for the older stands. These two experimental forests are largely complementary with respect to biomass. Radar backscatter is found to increase approximately linearly with increasing biomass until it saturates at a biomass level that depends on the radar frequency. The biomass saturation level is about 200 tons/ha at P-band and 100 tons/ha at L-band, and the C-band backscattering coefficient shows much less sensitivity to total aboveground biomass.

  5. Retrieval of pine forest biomass using JPL AIRSAR data

    NASA Technical Reports Server (NTRS)

    Beaudoin, A.; Letoan, T.; Zagolski, F.; Hsu, C. C.; Han, H. C.; Kong, J. A.

    1992-01-01

    The analysis of Jet Propulsion Laboratory (JPL) Airborne Synthetic Aperture Radar (AIRSAR) data over the Landes forest in South-West France revealed strong correlation between L- and especially P-band sigma degrees and the pine forest biomass. To explain the physical link of radar backscatter to biomass, a polarimetric backscattering model was developed and validated. Then the model was used in a simulation study to predict sigma degree sensitivity to undesired canopy and environmental parameters. Main results concerning the data analysis, modeling, and simulation at P-band are reported.

  6. Forest harvesting reduces the soil metagenomic potential for biomass decomposition.

    PubMed

    Cardenas, Erick; Kranabetter, J M; Hope, Graeme; Maas, Kendra R; Hallam, Steven; Mohn, William W

    2015-11-01

    Soil is the key resource that must be managed to ensure sustainable forest productivity. Soil microbial communities mediate numerous essential ecosystem functions, and recent studies show that forest harvesting alters soil community composition. From a long-term soil productivity study site in a temperate coniferous forest in British Columbia, 21 forest soil shotgun metagenomes were generated, totaling 187 Gb. A method to analyze unassembled metagenome reads from the complex community was optimized and validated. The subsequent metagenome analysis revealed that, 12 years after forest harvesting, there were 16% and 8% reductions in relative abundances of biomass decomposition genes in the organic and mineral soil layers, respectively. Organic and mineral soil layers differed markedly in genetic potential for biomass degradation, with the organic layer having greater potential and being more strongly affected by harvesting. Gene families were disproportionately affected, and we identified 41 gene families consistently affected by harvesting, including families involved in lignin, cellulose, hemicellulose and pectin degradation. The results strongly suggest that harvesting profoundly altered below-ground cycling of carbon and other nutrients at this site, with potentially important consequences for forest regeneration. Thus, it is important to determine whether these changes foreshadow long-term changes in forest productivity or resilience and whether these changes are broadly characteristic of harvested forests.

  7. Aboveground tree biomass on productive forest land in Alaska. Forest Service research paper

    SciTech Connect

    Yarie, J.; Mead, D.R.

    1982-08-01

    Total aboveground woody biomass of trees on forest land that can produce 1.4 cubic meters per hectare per year of industrial wood in Alaska is 1.33 billion metric tons green weight. The estimated energy value of the standing woody biomass is 11.9 x 10 Btu's. Statewide tables of biomass and energy values for softwoods, hardwoods, and species group are presented.

  8. Effects of forest biomass use for energy on the European forest litter and soil carbon stocks

    NASA Astrophysics Data System (ADS)

    Repo, A.; Kindermann, G.; Böttcher, H.; Liski, J.

    2012-04-01

    Producing bioenergy from forest harvest residues has been considered as an effective means to cut greenhouse gas emissions into the atmosphere and simultaneously to fulfil the renewable energy targets agreed in the European Union. Previous studies have estimated technical, realizable and sustainable potentials of forest bioenergy in Europe. However, in some cases, using bioenergy may not be only beneficial for the global climate. Increasing removals of branches, thinning wood and stumps from forest to energy use decreases carbon input to litter and soil, and therefore decreases the amount of carbon stored in dead wood, litter and soil. The carbon stock changes resulting from an increase in forest biomass extraction rates can decrease the overall net greenhouse gas emission reduction potential of forest bioenergy significantly. The decrease in the forest litter and soil carbon stocks, and the consequent effect on national greenhouse gas balances is different for different European countries due to variability e.g. in climatic conditions, biomass extraction rates and tree species composition. In this study we assess the response of European forest litter and soil carbon stocks with respect to an increase in forest residue energy use to realizable bioenergy potential and combined climate change feedbacks. We use geographically explicit model runs assuming a shift of climate variables over 2011-2100 to investigate expected effects of regional climate change on forest soil carbon stocks and contrast there results with estimates of the effects of increased forest biomass removal and energy use on litter and soil carbon stocks in Europe. The models used are G4M Global Forestry Model and Yasso07 litter and soil carbon model. By adding soil and litter carbon effects of producing bioenergy from forest residues on the forest carbon balance, a more comprehensive greenhouse gas emission budget of forest bioenergy options can be calculated. Keywords: forest bioenergy, carbon

  9. Liana effects on biomass dynamics strengthen during secondary forest succession.

    PubMed

    Lai, Hao Ran; Hall, Jefferson S; Turner, Benjamin L; van Breugel, Michiel

    2017-04-01

    Secondary forests are important carbon sinks, but their biomass dynamics vary markedly within and across landscapes. The biotic and abiotic drivers of this variation are still not well understood. We tested the effects of soil resource availability and competition by lianas on the biomass dynamics of young secondary tropical forests in Panama and assessed the extent to which liana effects were mediated by soil resource availability. Over a five-year period, growth, mortality, and recruitment of woody plants of ≥1 cm diameter were monitored in 84 plots in 3-30-year-old secondary forests across the Agua Salud site in central Panama. Biomass dynamics and the effects of lianas and soil resources were examined using (generalized) linear mixed-effect models and a model averaging approach. There was strong spatial and temporal variation in liana biomass within and across the plots. The relative biomass of lianas had a strong negative effect on overall tree growth, growth of understory trees decreased with soil fertility and dry season soil water content, and the effect of lianas on tree mortality varied with soil fertility. Tree recruitment was not associated with any of the predictor variables. Our model indicates that tree biomass growth across our landscape was reduced with 22% due to competition with lianas, and that the effect of lianas increased during succession, from 19% after five years to 32% after 30 years. The projected liana-induced growth reduction after 60 years was 47%, which was consistent with data from a nearby site. Our study shows that the observed liana proliferation across tropical forests may reduce the sequestration and storage of carbon in young secondary forests, with important implications for the carbon balance of tropical forest landscapes and consequently for global climate change. Our study highlights the need to incorporate lianas and soil variables in research on the biomass dynamics of secondary forest across tropical landscapes

  10. Deadwood biomass: an underestimated carbon stock in degraded tropical forests?

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  11. 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.

  12. Mapping aboveground forest biomass combining dendrometric data and spectral signature of forest species

    NASA Astrophysics Data System (ADS)

    Avocat, H.; Tourneux, F.

    2013-12-01

    Accurate measures and explicit spatial representations of forest biomass compose an important aspect to model the forest productivity and crops, and to implement sustainable forest management. Several methods have been developed to estimate and to map forest biomass, combining point-sources measurements of biophysical variables such as diameter-at-breast height (DBH), tree height, crown size, crown length, crown volume and remote sensing data (spectral vegetation index values). In this study, we propose a new method for aboveground biomass (AGB) mapping of forests and isolated trees. This method is tested on a 1100 km2 area located in the eastern France. In contrast to most of studies, our model is not calibrated using field plot measurements or point-source inventory data. The primary goal of this model is to propose an accessible and reproducible method for AGB mapping of temperate forests, by combining standard biomass values coming from bibliography and remotely sensed data. This method relies on three steps. (1) The first step consists of produce a map of wooded areas including small woods and isolated trees, and to identify the major forest stands. To do this, we use an unsupervised classification of a Landsat 7 ETM+ image. Results are compared and improved with various land cover data. (2) The second step consists of extract the normalized difference vegetation index (NDVI) values of main forest stands. (3) Finally, these values are combined with standard AGB values provided by bibliography, to calibrate four AGB estimation models of different forest types (broadleaves, coniferous, coppices, and mixed stands). This method provides a map of aboveground biomass for forests and isolated trees with a 30 meters spatial resolution. Results demonstrate that 71 % of AGB values for hardwoods vary between 143 and 363 t.ha-1, i.e. × 1 standard deviation around the average. For coniferous stands, most of values of AGB range from 167 to 256 t.ha-1.

  13. Measuring Forest Height and Biomass from Space

    NASA Technical Reports Server (NTRS)

    Agueh, Temilola Elisabeth Fato

    2013-01-01

    Talk about doing earth science at NASA and how what we do is focus on the biosphere- that is the living portion of the earth.In particular, we are interested in looking at forests-quantifying deforestation, regrowth, change in general and helping develop new cutting-edge technologies and instruments to be able to measure these changes in land use, land cover and quality more accurately.

  14. Biogeographical patterns of forest biomass allocation vary by climate, soil and forest characteristics in China

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Song, Tongqing; Wang, Kelin; Wang, Genxuan; Liao, Jianxiong; Xu, Guanghua; Zeng, Fuping

    2015-04-01

    To explore whether the large-scale patterns of biomass allocation vary by climate, soil, and forest characteristics in terrestrial ecosystems, on the basis of the national forest inventory data (2004-2008) and our previous field measurements (2011-2012), we investigated the variation of four biomass allocation fractions (BAFs), and their relationship with environmental factors (e.g. climate and soil chemistry) and forest characteristics (e.g. stand age and stand density) across 11 of China’s forest types. Our results revealed that BAFs have significant latitudinal, longitudinal and altitudinal trends. Stepwise multiple regression models that involve the climate, soil and forest stand properties account for a part of the biogeographical variation in BAFs, and the stand age, stand density and mean growing season temperature mainly explain these variations. Reduced major axis regression models showed that BAFs differ in their sensitivity (slope of their response to environmental gradients) to climate, soil and forest characteristics among different forest types. The results of the current study do not support the isometric allocation hypothesis, which suggests that component biomass scales equivalently as total biomass across different plant species along environmental gradients.

  15. 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

  16. Woody biomass resource of Louisiana, 1991. Forest Service resource bulletin

    SciTech Connect

    Rosson, J.F.

    1993-09-01

    Data from the 1991 Louisiana forest survey were used to derive fresh and dry biomass estimates for all trees, on timberland, greater than 1.0 inch in diameter at breast height (d.b.h.). There are 470.0 million fresh tons in softwood species and 757.5 million fresh tons in hardwood species. The woody biomass resource averages 45.9 and 61.9 tons per acre for softwoods and hardwoods where they occur, respectively. Most of this biomass is in the stem portion of the trees--85 percent for softwoods and 75 percent for hardwoods. Nonindustrial private landowners hold 58 and 69 percent of the total softwood and hardwood biomass resource, respectively.

  17. China Forest Aboveground Biomass Estimation by Fusion of Inventory and Remote Sensing Data: 1st results from Heilongjiang Province and Yunnan Province

    NASA Astrophysics Data System (ADS)

    Pang, Y.; Li, Z.; Huang, G.; Sun, G.; Cheng, Z.; Zhang, Z.; Zhang, G.

    2013-12-01

    Forests play an irreplaceable role in maintaining regional ecological environment, global carbon balance and mitigating global climate change. Forest aboveground biomass (AGB) is an important indicator of forest carbon stocks. Estimating forest aboveground biomass accurately could significantly reduce the uncertainties in terrestrial ecosystem carbon cycle. LIDAR provides accurate information on the vertical structure of forests (Lefsky et al., 2007; Naesset et al., 2004; Pang et al., 2008). Combining airborne LiDAR and spaceborne LiDAR for regional forest biomass retrieval could provide a more reliable and accurate quantitative information in regional forest biomass estimate (Boudreau et al., 2008; Nelson et al., 2009; Pang et al., 2011; Saatchi et al., 2011). The Heilongjiang Province and Yunnan Province are rich in forest resources and suffers intensive forest management activities for timber products. The Heilongjiang Province is typical in temperate forest and the Yunnan Province contains multiple forest types including tropical forest. These two provinces also have good ground inventory system with thousands of permanent field plots. Two campaign consists of in-situ measurement, airborne Lidar data and spaceborne data fusion were designed and implemented. First results show that i). Both spaceborne lidar and forest inventory data are useful for AGB mapping at province level. ii). The combination of spaceborne lidar and forest inventory data gave better biomass estimation with less bias. iii). A pixel level bias mapping was also proposed and gave spatial explicit map of estimation uncertainties. This method will be investigated further with more reference data and tested in other area.

  18. Error propagation and scaling for tropical forest biomass estimates.

    PubMed Central

    Chave, Jerome; Condit, Richard; Aguilar, Salomon; Hernandez, Andres; Lao, Suzanne; Perez, Rolando

    2004-01-01

    The above-ground biomass (AGB) of tropical forests is a crucial variable for ecologists, biogeochemists, foresters and policymakers. Tree inventories are an efficient way of assessing forest carbon stocks and emissions to the atmosphere during deforestation. To make correct inferences about long-term changes in biomass stocks, it is essential to know the uncertainty associated with AGB estimates, yet this uncertainty is rarely evaluated carefully. Here, we quantify four types of uncertainty that could lead to statistical error in AGB estimates: (i) error due to tree measurement; (ii) error due to the choice of an allometric model relating AGB to other tree dimensions; (iii) sampling uncertainty, related to the size of the study plot; (iv) representativeness of a network of small plots across a vast forest landscape. In previous studies, these sources of error were reported but rarely integrated into a consistent framework. We estimate all four terms in a 50 hectare (ha, where 1 ha = 10(4) m2) plot on Barro Colorado Island, Panama, and in a network of 1 ha plots scattered across central Panama. We find that the most important source of error is currently related to the choice of the allometric model. More work should be devoted to improving the predictive power of allometric models for biomass. PMID:15212093

  19. Bringing Together Users and Developers of Forest Biomass Maps

    NASA Technical Reports Server (NTRS)

    Brown, Molly Elizabeth; Macauley, Molly K.

    2012-01-01

    Forests store carbon and thus represent important sinks for atmospheric carbon dioxide. Reducing uncertainty in current estimates of the amount of carbon in standing forests will improve precision of estimates of anthropogenic contributions to carbon dioxide in the atmosphere due to deforestation. Although satellite remote sensing has long been an important tool for mapping land cover, until recently aboveground forest biomass estimates have relied mostly on systematic ground sampling of forests. In alignment with fiscal year 2010 congressional direction, NASA has initiated work toward a carbon monitoring system (CMS) that includes both maps of forest biomass and total carbon flux estimates. A goal of the project is to ensure that the products are useful to a wide community of scientists, managers, and policy makers, as well as to carbon cycle scientists. Understanding the needs and requirements of these data users is helpful not just to the NASA CMS program but also to the entire community working on carbon-related activities. To that end, this meeting brought together a small group of natural resource managers and policy makers who use information on forests in their work with NASA scientists who are working to create aboveground forest biomass maps. These maps, derived from combining remote sensing and ground plots, aim to be more accurate than current inventory approaches when applied at local and regional scales. Meeting participants agreed that users of biomass information will look to the CMS effort not only to provide basic data for carbon or biomass measurements but also to provide data to help serve a broad range of goals, such as forest watershed management for water quality, habitat management for biodiversity and ecosystem services, and potential use for developing payments for ecosystem service projects. Participants also reminded the CMS group that potential users include not only public sector agencies and nongovernmental organizations but also the

  20. Forest biomass carbon sinks in East Asia, with special reference to the relative contributions of forest expansion and forest growth.

    PubMed

    Fang, Jingyun; Guo, Zhaodi; Hu, Huifeng; Kato, Tomomichi; Muraoka, Hiroyuki; Son, Yowhan

    2014-06-01

    Forests play an important role in regional and global carbon (C) cycles. With extensive afforestation and reforestation efforts over the last several decades, forests in East Asia have largely expanded, but the dynamics of their C stocks have not been fully assessed. We estimated biomass C stocks of the forests in all five East Asian countries (China, Japan, North Korea, South Korea, and Mongolia) between the 1970s and the 2000s, using the biomass expansion factor method and forest inventory data. Forest area and biomass C density in the whole region increased from 179.78 × 10(6) ha and 38.6 Mg C ha(-1) in the 1970s to 196.65 × 10(6) ha and 45.5 Mg C ha(-1) in the 2000s, respectively. The C stock increased from 6.9 Pg C to 8.9 Pg C, with an averaged sequestration rate of 66.9 Tg C yr(-1). Among the five countries, China and Japan were two major contributors to the total region's forest C sink, with respective contributions of 71.1% and 32.9%. In China, the areal expansion of forest land was a larger contributor to C sinks than increased biomass density for all forests (60.0% vs. 40.0%) and for planted forests (58.1% vs. 41.9%), while the latter contributed more than the former for natural forests (87.0% vs. 13.0%). In Japan, increased biomass density dominated the C sink for all (101.5%), planted (91.1%), and natural (123.8%) forests. Forests in South Korea also acted as a C sink, contributing 9.4% of the total region's sink because of increased forest growth (98.6%). Compared to these countries, the reduction in forest land in both North Korea and Mongolia caused a C loss at an average rate of 9.0 Tg C yr(-1), equal to 13.4% of the total region's C sink. Over the last four decades, the biomass C sequestration by East Asia's forests offset 5.8% of its contemporary fossil-fuel CO2 emissions.

  1. Estimation of Boreal Forest Biomass Using Spaceborne SAR Systems

    NASA Technical Reports Server (NTRS)

    Saatchi, Sassan; Moghaddam, Mahta

    1995-01-01

    In this paper, we report on the use of a semiempirical algorithm derived from a two layer radar backscatter model for forest canopies. The model stratifies the forest canopy into crown and stem layers, separates the structural and biometric attributes of the canopy. The structural parameters are estimated by training the model with polarimetric SAR (synthetic aperture radar) data acquired over homogeneous stands with known above ground biomass. Given the structural parameters, the semi-empirical algorithm has four remaining parameters, crown biomass, stem biomass, surface soil moisture, and surface rms height that can be estimated by at least four independent SAR measurements. The algorithm has been used to generate biomass maps over the entire images acquired by JPL AIRSAR and SIR-C SAR systems. The semi-empirical algorithms are then modified to be used by single frequency radar systems such as ERS-1, JERS-1, and Radarsat. The accuracy. of biomass estimation from single channel radars is compared with the case when the channels are used together in synergism or in a polarimetric system.

  2. Forest Biomass retrieval strategies from Lidar and Radar modeling

    NASA Astrophysics Data System (ADS)

    Sun, G.; Ranson, J.

    2008-12-01

    Estimates of regional and global forest biomass and forest structure are essential for understanding and monitoring ecosystem responses to human activities and climate change. Lidars with capabilities of recording the time-varying return signals provide vegetation height, ground surface height, and vertical distribution of vegetated surfaces intercepted by laser pulses. Large footprint lidar has been shown to be an effective technique for measuring forest canopy height, and biomass from space. Essentially, radar responds to the amount of water in a forest canopy, as well as its spatial structure. Data from these sensors contain information relevant to different aspects of the biophysical properties of the vegetation canopy including above ground biomass. The planned NASA new mission DESDynI will provide global systematic lidar sampling data and complete global coverage of L-band high resolution SAR and InSAR data for vegetation 3D structure mapping. By combining lidar and high-resolution SAR data, our quantitative knowledge of global carbon dynamics and ecosystem structure and function can be improved. This requires some new data processing and fusion technologies. What is the proper lidar sampling design and how to expand the vegetation spatial structural parameters estimated at lidar footprints to global spatial coverage in high resolution need to be resolved. Current configuration of DESDynI may also require lidar observations with variable looking angles, which creates a new challenge in lidar data processing. Models designed to simulate lidar and radar response from a variety of forest canopies can help answer these questions. In this paper we present an overview of our spatially explicit lidar and radar models and their use for examining the questions above. Specifically we will discuss sensitivities of large-footprint lidar and L-band polarimetric and interferometric radar to forest

  3. Doubling of the Russian Fire Return Interval: Implications for Forest Biomass and Composition

    NASA Astrophysics Data System (ADS)

    Shuman, J. K.; Foster, A.; Shugart, H. H., Jr.; Hoffman-Hall, A.; Loboda, T. V.

    2015-12-01

    The Russian boreal forest has experienced significant warming over the past several decades and this trend is expected to continue. This warming has the capacity to alter dominant vegetation and biomass dynamics through shifts in competition dynamics, a change in treeline and an increased fire disturbance regime. Historical fire return interval is calculated for the Russian ecoregions and applied to 31,010 points of a 22 x 22 km2 grid. Using an individual tree based forest gap model, UVAFME, biomass and species dynamics are simulated for multiple scenarios: without fire, with historical fire probabilities, a doubling of probabilities across the region, and the combined effect of fire with an altered climate. Fire disturbance within the model is a randomly occurring event with a variable intensity that alters the seedling bank and kills trees according to unique species fire tolerance parameters. Results from the simulation scenarios are compared to assess changes in biomass, species composition, and age structure 500 years after bare ground initiation. At the end of simulation, results which include fire disturbance show an increase in biomass across the region compared to simulation without fire. This increase in biomass in the simulations with fire disturbance is associated with an overall decrease in the age of the forest to younger more productive stands. The doubling of the fire return interval maintains a higher percentage of the needle leaf deciduous larch across Siberia. With altered climate, the region experiences an overall decrease in biomass and a shift in composition towards early successional deciduous species. These results reinforce the importance of the inclusion of complex competition and age structure in evaluating forest response to disturbance and changing climate.

  4. Spatio-temporal changes in biomass carbon sinks in China's forests from 1977 to 2008.

    PubMed

    Guo, Zhaodi; Hu, Huifeng; Li, Pin; Li, Nuyun; Fang, Jingyun

    2013-07-01

    Forests play a leading role in regional and global carbon (C) cycles. Detailed assessment of the temporal and spatial changes in C sinks/sources of China's forests is critical to the estimation of the national C budget and can help to constitute sustainable forest management policies for climate change. In this study, we explored the spatio-temporal changes in forest biomass C stocks in China between 1977 and 2008, using six periods of the national forest inventory data. According to the definition of the forest inventory, China's forest was categorized into three groups: forest stand, economic forest, and bamboo forest. We estimated forest biomass C stocks for each inventory period by using continuous biomass expansion factor (BEF) method for forest stands, and the mean biomass density method for economic and bamboo forests. As a result, China's forests have accumulated biomass C (i.e., biomass C sink) of 1896 Tg (1 Tg=10(12) g) during the study period, with 1710, 108 and 78 Tg C in forest stands, and economic and bamboo forests, respectively. Annual forest biomass C sink was 70.2 Tg C a(-1), offsetting 7.8% of the contemporary fossil CO2 emissions in the country. The results also showed that planted forests have functioned as a persistent C sink, sequestrating 818 Tg C and accounting for 47.8% of total C sink in forest stands, and that the old-, mid- and young-aged forests have sequestrated 930, 391 and 388 Tg C from 1977 to 2008. Our results suggest that China's forests have a big potential as biomass C sink in the future because of its large area of planted forests with young-aged growth and low C density.

  5. Estimating forest and woodland aboveground biomass using active and passive remote sensing

    USGS Publications Warehouse

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

    2016-01-01

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

  6. Effects of harvest management practices on forest biomass and soil carbon in eucalypt forests in New South Wales, Australia: Simulations with the forest succession model LINKAGES

    SciTech Connect

    Ranatunga, Kemachandra; Keenan, Rodney J.; Wullschleger, Stan D; Post, Wilfred M; Tharp, M Lynn

    2008-01-01

    Understanding long-term changes in forest ecosystem carbon stocks under forest management practices such as timber harvesting is important for assessing the contribution of forests to the global carbon cycle. Harvesting effects are complicated by the amount, type, and condition of residue left on-site, the decomposition rate of this residue, the incorporation of residue into soil organic matter and the rate of new detritus input to the forest floor from regrowing vegetation. In an attempt to address these complexities, the forest succession model LINKAGES was used to assess the production of aboveground biomass, detritus, and soil carbon stocks in native Eucalyptus forests as influenced by five harvest management practices in New South Wales, Australia. The original decomposition sub-routines of LINKAGES were modified by adding components of the Rothamsted (RothC) soil organic matter turnover model. Simulation results using the new model were compared to data from long-term forest inventory plots. Good agreement was observed between simulated and measured above-ground biomass, but mixed results were obtained for basal area. Harvesting operations examined included removing trees for quota sawlogs (QSL, DBH >80 cm), integrated sawlogs (ISL, DBH >20 cm) and whole-tree harvesting in integrated sawlogs (WTH). We also examined the impact of different cutting cycles (20, 50 or 80 years) and intensities (removing 20, 50 or 80 m{sup 3}). Generally medium and high intensities of shorter cutting cycles in sawlog harvesting systems produced considerably higher soil carbon values compared to no harvesting. On average, soil carbon was 2-9% lower in whole-tree harvest simulations whereas in sawlog harvest simulations soil carbon was 5-17% higher than in no harvesting.

  7. Wildfires in bamboo-dominated Amazonian forest: impacts on above-ground biomass and biodiversity.

    PubMed

    Barlow, Jos; Silveira, Juliana M; Mestre, Luiz A M; Andrade, Rafael B; Camacho D'Andrea, Gabriela; Louzada, Julio; Vaz-de-Mello, Fernando Z; Numata, Izaya; Lacau, Sébastien; Cochrane, Mark A

    2012-01-01

    Fire has become an increasingly important disturbance event in south-western Amazonia. We conducted the first assessment of the ecological impacts of these wildfires in 2008, sampling forest structure and biodiversity along twelve 500 m transects in the Chico Mendes Extractive Reserve, Acre, Brazil. Six transects were placed in unburned forests and six were in forests that burned during a series of forest fires that occurred from August to October 2005. Normalized Burn Ratio (NBR) calculations, based on Landsat reflectance data, indicate that all transects were similar prior to the fires. We sampled understorey and canopy vegetation, birds using both mist nets and point counts, coprophagous dung beetles and the leaf-litter ant fauna. Fire had limited influence upon either faunal or floral species richness or community structure responses, and stems <10 cm DBH were the only group to show highly significant (p = 0.001) community turnover in burned forests. Mean aboveground live biomass was statistically indistinguishable in the unburned and burned plots, although there was a significant increase in the total abundance of dead stems in burned plots. Comparisons with previous studies suggest that wildfires had much less effect upon forest structure and biodiversity in these south-western Amazonian forests than in central and eastern Amazonia, where most fire research has been undertaken to date. We discuss potential reasons for the apparent greater resilience of our study plots to wildfire, examining the role of fire intensity, bamboo dominance, background rates of disturbance, landscape and soil conditions.

  8. Wildfires in Bamboo-Dominated Amazonian Forest: Impacts on Above-Ground Biomass and Biodiversity

    PubMed Central

    Barlow, Jos; Silveira, Juliana M.; Mestre, Luiz A. M.; Andrade, Rafael B.; Camacho D'Andrea, Gabriela; Louzada, Julio; Vaz-de-Mello, Fernando Z.; Numata, Izaya; Lacau, Sébastien; Cochrane, Mark A.

    2012-01-01

    Fire has become an increasingly important disturbance event in south-western Amazonia. We conducted the first assessment of the ecological impacts of these wildfires in 2008, sampling forest structure and biodiversity along twelve 500 m transects in the Chico Mendes Extractive Reserve, Acre, Brazil. Six transects were placed in unburned forests and six were in forests that burned during a series of forest fires that occurred from August to October 2005. Normalized Burn Ratio (NBR) calculations, based on Landsat reflectance data, indicate that all transects were similar prior to the fires. We sampled understorey and canopy vegetation, birds using both mist nets and point counts, coprophagous dung beetles and the leaf-litter ant fauna. Fire had limited influence upon either faunal or floral species richness or community structure responses, and stems <10 cm DBH were the only group to show highly significant (p = 0.001) community turnover in burned forests. Mean aboveground live biomass was statistically indistinguishable in the unburned and burned plots, although there was a significant increase in the total abundance of dead stems in burned plots. Comparisons with previous studies suggest that wildfires had much less effect upon forest structure and biodiversity in these south-western Amazonian forests than in central and eastern Amazonia, where most fire research has been undertaken to date. We discuss potential reasons for the apparent greater resilience of our study plots to wildfire, examining the role of fire intensity, bamboo dominance, background rates of disturbance, landscape and soil conditions. PMID:22428035

  9. Global patterns and predictions of seafloor biomass using random forests.

    PubMed

    Wei, Chih-Lin; Rowe, Gilbert T; Escobar-Briones, Elva; Boetius, Antje; Soltwedel, Thomas; Caley, M Julian; Soliman, Yousria; Huettmann, Falk; Qu, Fangyuan; Yu, Zishan; Pitcher, C Roland; Haedrich, Richard L; Wicksten, Mary K; Rex, Michael A; Baguley, Jeffrey G; Sharma, Jyotsna; Danovaro, Roberto; MacDonald, Ian R; Nunnally, Clifton C; Deming, Jody W; Montagna, Paul; Lévesque, Mélanie; Weslawski, Jan Marcin; Wlodarska-Kowalczuk, Maria; Ingole, Baban S; Bett, Brian J; Billett, David S M; Yool, Andrew; Bluhm, Bodil A; Iken, Katrin; Narayanaswamy, Bhavani E

    2010-12-30

    A comprehensive seafloor biomass and abundance database has been constructed from 24 oceanographic institutions worldwide within the Census of Marine Life (CoML) field projects. The machine-learning algorithm, Random Forests, was employed to model and predict seafloor standing stocks from surface primary production, water-column integrated and export particulate organic matter (POM), seafloor relief, and bottom water properties. The predictive models explain 63% to 88% of stock variance among the major size groups. Individual and composite maps of predicted global seafloor biomass and abundance are generated for bacteria, meiofauna, macrofauna, and megafauna (invertebrates and fishes). Patterns of benthic standing stocks were positive functions of surface primary production and delivery of the particulate organic carbon (POC) flux to the seafloor. At a regional scale, the census maps illustrate that integrated biomass is highest at the poles, on continental margins associated with coastal upwelling and with broad zones associated with equatorial divergence. Lowest values are consistently encountered on the central abyssal plains of major ocean basins The shift of biomass dominance groups with depth is shown to be affected by the decrease in average body size rather than abundance, presumably due to decrease in quantity and quality of food supply. This biomass census and associated maps are vital components of mechanistic deep-sea food web models and global carbon cycling, and as such provide fundamental information that can be incorporated into evidence-based management.

  10. Global Patterns and Predictions of Seafloor Biomass Using Random Forests

    PubMed Central

    Wei, Chih-Lin; Rowe, Gilbert T.; Escobar-Briones, Elva; Boetius, Antje; Soltwedel, Thomas; Caley, M. Julian; Soliman, Yousria; Huettmann, Falk; Qu, Fangyuan; Yu, Zishan; Pitcher, C. Roland; Haedrich, Richard L.; Wicksten, Mary K.; Rex, Michael A.; Baguley, Jeffrey G.; Sharma, Jyotsna; Danovaro, Roberto; MacDonald, Ian R.; Nunnally, Clifton C.; Deming, Jody W.; Montagna, Paul; Lévesque, Mélanie; Weslawski, Jan Marcin; Wlodarska-Kowalczuk, Maria; Ingole, Baban S.; Bett, Brian J.; Billett, David S. M.; Yool, Andrew; Bluhm, Bodil A.; Iken, Katrin; Narayanaswamy, Bhavani E.

    2010-01-01

    A comprehensive seafloor biomass and abundance database has been constructed from 24 oceanographic institutions worldwide within the Census of Marine Life (CoML) field projects. The machine-learning algorithm, Random Forests, was employed to model and predict seafloor standing stocks from surface primary production, water-column integrated and export particulate organic matter (POM), seafloor relief, and bottom water properties. The predictive models explain 63% to 88% of stock variance among the major size groups. Individual and composite maps of predicted global seafloor biomass and abundance are generated for bacteria, meiofauna, macrofauna, and megafauna (invertebrates and fishes). Patterns of benthic standing stocks were positive functions of surface primary production and delivery of the particulate organic carbon (POC) flux to the seafloor. At a regional scale, the census maps illustrate that integrated biomass is highest at the poles, on continental margins associated with coastal upwelling and with broad zones associated with equatorial divergence. Lowest values are consistently encountered on the central abyssal plains of major ocean basins The shift of biomass dominance groups with depth is shown to be affected by the decrease in average body size rather than abundance, presumably due to decrease in quantity and quality of food supply. This biomass census and associated maps are vital components of mechanistic deep-sea food web models and global carbon cycling, and as such provide fundamental information that can be incorporated into evidence-based management. PMID:21209928

  11. Forest biomass carbon stocks and variation in Tibet’s carbon-dense forests from 2001 to 2050

    PubMed Central

    Sun, Xiangyang; Wang, Genxu; Huang, Mei; Chang, Ruiying; Ran, Fei

    2016-01-01

    Tibet’s forests, in contrast to China’s other forests, are characterized by primary forests, high carbon (C) density and less anthropogenic disturbance, and they function as an important carbon pool in China. Using the biomass C density data from 413 forest inventory sites and a spatial forest age map, we developed an allometric equation for the forest biomass C density and forest age to assess the spatial biomass C stocks and variation in Tibet’s forests from 2001 to 2050. The results indicated that the forest biomass C stock would increase from 831.1 Tg C in 2001 to 969.4 Tg C in 2050, with a net C gain of 3.6 Tg C yr−1 between 2001 and 2010 and a decrease of 1.9 Tg C yr−1 between 2040 and 2050. Carbon tends to allocate more in the roots of fir forests and less in the roots of spruce and pine forests with increasing stand age. The increase of the biomass carbon pool does not promote significant augmentation of the soil carbon pool. Our findings suggest that Tibet’s mature forests will remain a persistent C sink until 2050. However, afforestation or reforestation, especially with the larger carbon sink potential forest types, such as fir and spruce, should be carried out to maintain the high C sink capacity. PMID:27703215

  12. Rapid Assessment of U.S. Forest and Soil Organic Carbon Storage and Forest Biomass Carbon-Sequestration Capacity

    USGS Publications Warehouse

    Sundquist, Eric T.; Ackerman, Katherine V.; Bliss, Norman B.; Kellndorfer, Josef M.; Reeves, Matt C.; Rollins, Matthew G.

    2009-01-01

    This report provides results of a rapid assessment of biological carbon stocks and forest biomass carbon sequestration capacity in the conterminous United States. Maps available from the U.S. Department of Agriculture are used to calculate estimates of current organic carbon storage in soils (73 petagrams of carbon, or PgC) and forest biomass (17 PgC). Of these totals, 3.5 PgC of soil organic carbon and 0.8 PgC of forest biomass carbon occur on lands managed by the U.S. Department of the Interior (DOI). Maps of potential vegetation are used to estimate hypothetical forest biomass carbon sequestration capacities that are 3-7 PgC higher than current forest biomass carbon storage in the conterminous United States. Most of the estimated hypothetical additional forest biomass carbon sequestration capacity is accrued in areas currently occupied by agriculture and development. Hypothetical forest biomass carbon sequestration capacities calculated for existing forests and woodlands are within +or- 1 PgC of estimated current forest biomass carbon storage. Hypothetical forest biomass sequestration capacities on lands managed by the DOI in the conterminous United States are 0-0.4 PgC higher than existing forest biomass carbon storage. Implications for forest and other land management practices are not considered in this report. Uncertainties in the values reported here are large and difficult to quantify, particularly for hypothetical carbon sequestration capacities. Nevertheless, this rapid assessment helps to frame policy and management discussion by providing estimates that can be compared to amounts necessary to reduce predicted future atmospheric carbon dioxide levels.

  13. Rapid assessment of U.S. forest and soil organic carbon storage and forest biomass carbon-sequestration capacity

    USGS Publications Warehouse

    Sundquist, Eric T.; Ackerman, Katherine V.; Bliss, Norman B.; Kellndorfer, Josef M.; Reeves, Matt C.; Rollins, Matthew G.

    2009-01-01

    This report provides results of a rapid assessment of biological carbon stocks and forest biomass carbon sequestration capacity in the conterminous United States. Maps available from the U.S. Department of Agriculture are used to calculate estimates of current organic carbon storage in soils (73 petagrams of carbon, or PgC) and forest biomass (17 PgC). Of these totals, 3.5 PgC of soil organic carbon and 0.8 PgC of forest biomass carbon occur on lands managed by the U.S. Department of the Interior (DOI). Maps of potential vegetation are used to estimate hypothetical forest biomass carbon sequestration capacities that are 3–7 PgC higher than current forest biomass carbon storage in the conterminous United States. Most of the estimated hypothetical additional forest biomass carbon sequestration capacity is accrued in areas currently occupied by agriculture and development. Hypothetical forest biomass carbon sequestration capacities calculated for existing forests and woodlands are within ±1 PgC of estimated current forest biomass carbon storage. Hypothetical forest biomass sequestration capacities on lands managed by the DOI in the conterminous United States are 0–0.4 PgC higher than existing forest biomass carbon storage. Implications for forest and other land management practices are not considered in this report. Uncertainties in the values reported here are large and difficult to quantify, particularly for hypothetical carbon sequestration capacities. Nevertheless, this rapid assessment helps to frame policy and management discussion by providing estimates that can be compared to amounts necessary to reduce predicted future atmospheric carbon dioxide levels.

  14. High-Biomass Forests of the Pacific Northwest: Who Manages Them and How Much is Protected?

    NASA Astrophysics Data System (ADS)

    Krankina, Olga N.; DellaSala, Dominick A.; Leonard, Jessica; Yatskov, Mikhail

    2014-07-01

    To examine ownership and protection status of forests with high-biomass stores (>200 Mg/ha) in the Pacific Northwest (PNW) region of the United States, we used the latest versions of publicly available datasets. Overlay, aggregation, and GIS-based computation of forest area in broad biomass classes in the PNW showed that the National Forests contained the largest area of high-biomass forests (48.4 % of regional total), but the area of high-biomass forest on private lands was important as well (22.8 %). Between 2000 and 2008, the loss of high-biomass forests to fire on the National Forests was 7.6 % (236,000 ha), while the loss of high-biomass forest to logging on private lands (364,000 ha) exceeded the losses to fire across all ownerships. Many remaining high-biomass forest stands are vulnerable to future harvest as only 20 % are strictly protected from logging, while 26 % are not protected at all. The level of protection for high-biomass forests varies by state, for example, 31 % of all high-biomass federal forests in Washington are in high-protection status compared to only 9 % in Oregon. Across the conterminous US, high-biomass forest covers <3 % of all forest land and the PNW region holds 56.8 % of this area or 5.87 million ha. Forests with high-biomass stores are important to document and monitor as they are scarce, often threatened by harvest and development, and their disturbance including timber harvest results in net C losses to the atmosphere that can take a new generation of trees many decades or centuries to offset.

  15. High-biomass forests of the Pacific Northwest: who manages them and how much is protected?

    PubMed

    Krankina, Olga N; DellaSala, Dominick A; Leonard, Jessica; Yatskov, Mikhail

    2014-07-01

    To examine ownership and protection status of forests with high-biomass stores (>200 Mg/ha) in the Pacific Northwest (PNW) region of the United States, we used the latest versions of publicly available datasets. Overlay, aggregation, and GIS-based computation of forest area in broad biomass classes in the PNW showed that the National Forests contained the largest area of high-biomass forests (48.4 % of regional total), but the area of high-biomass forest on private lands was important as well (22.8 %). Between 2000 and 2008, the loss of high-biomass forests to fire on the National Forests was 7.6 % (236,000 ha), while the loss of high-biomass forest to logging on private lands (364,000 ha) exceeded the losses to fire across all ownerships. Many remaining high-biomass forest stands are vulnerable to future harvest as only 20 % are strictly protected from logging, while 26 % are not protected at all. The level of protection for high-biomass forests varies by state, for example, 31 % of all high-biomass federal forests in Washington are in high-protection status compared to only 9 % in Oregon. Across the conterminous US, high-biomass forest covers <3 % of all forest land and the PNW region holds 56.8 % of this area or 5.87 million ha. Forests with high-biomass stores are important to document and monitor as they are scarce, often threatened by harvest and development, and their disturbance including timber harvest results in net C losses to the atmosphere that can take a new generation of trees many decades or centuries to offset.

  16. Biomass Mapping of US forests using synergy of Synthetic Aperture Radar and optical Remote Sensing

    NASA Astrophysics Data System (ADS)

    Kellndorfer, J. M.; Baccini, A.; Bishop, J.; Cartus, O.; Cormier, T.; Walker, W. S.; Santoro, M.

    2011-12-01

    Santoro et al. (2011) for hyper-temporal stacks of ENVISAT ASAR C-band intensity, in which a semi-empirical model, relating backscatter to forest biophysical parameters, is trained with the aid of the MODIS VCF (Hansen et al., 2003) or similar optical remote sensing products. This algorithm allows accounting for environmental (soil/canopy moisture) or weather (freeze/thaw, rain) related effects on the backscatter signatures over forest without further need for in situ data. Once the model has been trained, it can be inverted to estimate the biomass for each image at pixel level. Where multi-temporal data was available, a weighted multi-temporal combination of the single-image estimates was done to improve the estimates. A comparison with the NBCD map indicated that at full resolution the accuracy of the ALOS biomass maps were relatively low with root mean square differences, RMSD, in the range of 80 to 100 t/ha. When, however, aggregating the maps to pixel size of >500 m, the RMSD reduced to less than 30 t/ha. The feasibility of accuracte ALOS based biomass mapping, at least at aggregated scales, was confirmed when extracting from the maps county level biomass statistics and comparing these to FIA county-level statistics (R2=0.95).

  17. Tropical forests and the global carbon cycle: Estimating state and change in biomass density. Book chapter

    SciTech Connect

    Brown, S.

    1996-07-01

    This chapter discusses estimating the biomass density of forest vegetation. Data from inventories of tropical Asia and America were used to estimate biomass densities. Efforts to quantify forest disturbance suggest that population density, at subnational scales, can be used as a surrogate index to encompass all the anthropogenic activities (logging, slash-and-burn agriculture, grazing) that lead to degradation of tropical forest biomass density.

  18. Heat storage in forest biomass improves energy balance closure

    NASA Astrophysics Data System (ADS)

    Lindroth, A.; Mölder, M.; Lagergren, F.

    2010-01-01

    Temperature measurements in trunks and branches in a mature ca. 100 years-old mixed pine and spruce forest in central Sweden were used to estimate the heat storage in the tree biomass. The estimated heat flux in the sample trees and data on biomass distributions were used to scale up to stand level biomass heat fluxes. The rate of change of sensible and latent heat storage in the air layer below the level of the flux measurements was estimated from air temperature and humidity profile measurements and soil heat flux was estimated from heat flux plates and soil temperature measurements. The fluxes of sensible and latent heat from the forest were measured with an eddy covariance system in a tower. The analysis was made for a two-month period in summer of 1995. The tree biomass heat flux was the largest of the estimated storage components and varied between 40 and -35 W m-2 on summer days with nice weather. Averaged over two months the diurnal maximum of total heat storage was 45 W m-2 and the minimum was -35 W m-2. The soil heat flux and the sensible heat storage in air were out of phase with the biomass flux and they reached maximum values that were about 75% of the maximum of the tree biomass heat storage. The energy balance closure improved significantly when the total heat storage was added to the turbulent fluxes. The slope of a regression line with sum of fluxes and storage as independent and net radiation as dependent variable, increased from 0.86 to 0.95 for half-hourly data and the scatter was also reduced. The most significant finding was, however, that during nights with strongly stable conditions when the sensible heat flux dropped to nearly zero, the total storage matched the net radiation very well. Another interesting result was that the mean energy imbalance started to increase when the Richardson number became more negative than ca. -0.1. In fact, the largest energy deficit occurred at maximum instability. Our conclusion is that eddy covariance

  19. Considerations for Sustainable Biomass Production in Quercus-Dominated Forest Ecosystems

    NASA Astrophysics Data System (ADS)

    Bruckman, Viktor; Yan, Shuai; Hochbichler, Eduard

    2013-04-01

    Our current energy system is mainly based on carbon (C) intensive metabolisms, resulting in great effects on the earth's biosphere. The majority of the energy sources are fossil (crude oil, coal, natural gas) and release CO2 in the combustion (oxidation) process which takes place during utilization of the energy. C released to the atmosphere was once sequestered by biomass over a time span of millions of years and is now being released back into the atmosphere within a period of just decades. In the context of green and CO2 neutral Energy, there is an on-going debate regarding the potentials of obtaining biomass from forests on multiple scales, from stand to international levels. Especially in the context of energy, it is highlighted that biomass is an entirely CO2 neutral feedstock since the carbon stored in wood originates from the atmospheric CO2 pool and it was taken up during plant growth. It needs systems approaches in order to justify this statement and ensure sustainability covering the whole life-cycle from biomass production to (bio)energy consumption. There are a number of Quercus woodland management systems focussing solely on woody biomass production for energetic utilization or a combination with traditional forestry and high quality timber production for trades and industry. They have often developed regionally as a consequence of specific demands and local production capacities, which are mainly driven by environmental factors such as climate and soil properties. We assessed the nutritional status of a common Quercus-dominated forest ecosystem in northern Austria, where we compared biomass- with belowground C and nutrient pools in order to identify potential site limits if the management shifts towards systems with a higher level of nutrient extraction. Heterogeneity of soils, and soil processes are considered, as well as other, growth-limiting factors (e.g. precipitation) and species-specific metabolisms and element translocation.

  20. Biomass burning emissions estimates in the boreal forests of Siberia

    NASA Astrophysics Data System (ADS)

    Kukavskaya, E. A.; Ivanova, G. A.; Soja, A. J.; Conard, S. G.

    2012-04-01

    Wildfire is the main boreal forest disturbance and can burn 10-30 million hectares annually, thus modifying the global carbon budget through direct fire emissions, postfire biogenic emissions, and by maintaining or altering ecosystems through establishing the beginning and end of successional processes. Fires in the Russian boreal forest range from low-severity surface fires to high-severity crown fires. Estimates of carbon emissions from fires in Russian boreal forests vary substantially due to differences in ecosystems types, burned area calculations, and the amount of fuel consumed. There is an urgent need to obtain more accurate and impartial fire carbon loss estimates in the boreal forests of Siberia due to their considerable contribution to the regional and global carbon balance. We examined uncertainties in estimates of carbon emissions. Area burned in the Siberian region was analyzed and compared using distinct methodologies. Differences between mapped ecosystems were also compared and contrasted to evaluate the potential for error resulting from disparate vegetation structure and fuel consumption estimates. Accurate fuel consumption estimates are obtained in the course of fire experiments with pre- and post-fire biomass measuring. Our large-scale experiments carried out in the course of the FIRE BEAR (Fire Effects in the Boreal Eurasia Region) Project provided quantitative and qualitative data on ecosystem state and carbon emissions due to fires of known behavior in major forest types of Siberia that could be used to verify large-scale carbon emissions estimates. Carbon emissions from fires vary annually and interannually and can increase several times in extreme fire years in comparison to normal fire years. Climate change and increasing drought length have increased the probability of high-severity fire occurrences. This would result in greater carbon losses and efflux to the atmosphere. This research was supported by NASA LCLUC Program, Fulbright

  1. A review of biomass burning emissions part II: intensive physical properties of biomass burning particles

    NASA Astrophysics Data System (ADS)

    Reid, J. S.; Koppmann, R.; Eck, T. F.; Eleuterio, D. P.

    2005-03-01

    The last decade has seen tremendous advances in atmospheric aerosol particle research that is often performed in the context of climate and global change science. Biomass burning, one of the largest sources of accumulation mode particles globally, has been closely studied for its radiative, geochemical, and dynamic impacts. These studies have taken many forms including laboratory burns, in situ experiments, remote sensing, and modeling. While the differing perspectives of these studies have ultimately improved our qualitative understanding of biomass-burning issues, the varied nature of the work make inter-comparisons and resolutions of some specific issues difficult. In short, the literature base has become a milieu of small pieces of the biomass-burning puzzle. This manuscript, the second part of four, examines the properties of biomass-burning particle emissions. Here we review and discuss the literature concerning the measurement of smoke particle size, chemistry, thermodynamic properties, and emission factors. Where appropriate, critiques of measurement techniques are presented. We show that very large differences in measured particle properties have appeared in the literature, in particular with regards to particle carbon budgets. We investigate emissions uncertainties using scale analyses, which shows that while emission factors for grass and brush are relatively well known, very large uncertainties still exist in emission factors of boreal, temperate and some tropical forests. Based on an uncertainty analysis of the community data set of biomass burning measurements, we present simplified models for particle size and emission factors. We close this review paper with a discussion of the community experimental data, point to lapses in the data set, and prioritize future research topics.

  2. A review of biomass burning emissions, part II: Intensive physical properties of biomass burning particles

    NASA Astrophysics Data System (ADS)

    Reid, J. S.; Koppmann, R.; Eck, T. F.; Eleuterio, D. P.

    2004-09-01

    The last decade has seen tremendous advances in atmospheric aerosol particle research that is often performed in the context of climate and global change science. Biomass burning, one of the largest sources of accumulation mode particles globally, has been closely studied for its radiative, geochemical, and dynamic impacts. These studies have taken many forms including laboratory burns, in situ experiments, remote sensing, and modeling. While the differing perspectives of these studies have ultimately improved our qualitative understanding of biomass burning issues, the varied nature of the work make inter-comparisons and resolutions of some specific issues difficult. In short, the literature base has become a milieu of small pieces of the biomass-burning puzzle. This manuscript, the second part of four, examines the properties of biomass-burning particle emissions. Here we review and discuss the literature concerning the measurement of smoke particle size, chemistry, thermodynamic properties, and emission factors. Where appropriate, critiques of measurement techniques are presented. We show that very large differences in measured particle properties have appeared in the literature, in particular with regards to particle carbon budgets. We investigate emissions uncertainties using scale analyses, which shows that while emission factors for grass and brush are relatively well known, very large uncertainties still exist in emission factors of boreal, temperate and some tropical forests. Based on an uncertainty analysis of the community data set of biomass burning measurements, we present simplified models for particle size and emission factors. We close this review paper with a discussion of the community experimental data, point to lapses in the data set, and prioritize future research topics.

  3. Near Isometric Biomass Partitioning in Forest Ecosystems of China

    PubMed Central

    Hui, Dafeng; Wang, Jun; Shen, Weijun; Le, Xuan; Ganter, Philip; Ren, Hai

    2014-01-01

    Based on the isometric hypothesis, belowground plant biomass (MB) should scale isometrically with aboveground biomass (MA) and the scaling exponent should not vary with environmental factors. We tested this hypothesis using a large forest biomass database collected in China. Allometric scaling functions relating MB and MA were developed for the entire database and for different groups based on tree age, diameter at breast height, height, latitude, longitude or elevation. To investigate whether the scaling exponent is independent of these biotic and abiotic factors, we analyzed the relationship between the scaling exponent and these factors. Overall MB was significantly related to MA with a scaling exponent of 0.964. The scaling exponent of the allometric function did not vary with tree age, density, latitude, or longitude, but varied with diameter at breast height, height, and elevation. The mean of the scaling exponent over all groups was 0.986. Among 57 scaling relationships developed, 26 of the scaling exponents were not significantly different from 1. Our results generally support the isometric hypothesis. MB scaled near isometrically with MA and the scaling exponent did not vary with tree age, density, latitude, or longitude, but increased with tree size and elevation. While fitting a single allometric scaling relationship may be adequate, the estimation of MB from MA could be improved with size-specific scaling relationships. PMID:24466149

  4. Evaluation of forest structure, biomass and carbon sequestration in subtropical pristine forests of SW China.

    PubMed

    Nizami, Syed Moazzam; Yiping, Zhang; Zheng, Zheng; Zhiyun, Lu; Guoping, Yang; Liqing, Sha

    2017-03-01

    Very old natural forests comprising the species of Fagaceae (Lithocarpus xylocarpus, Castanopsis wattii, Lithocarpus hancei) have been prevailing since years in the Ailaoshan Mountain Nature Reserve (AMNR) SW China. Within these forest trees, density is quite variable. We studied the forest structure, stand dynamics and carbon density at two different sites to know the main factors which drives carbon sequestration process in old forests by considering the following questions: How much is the carbon density in these forest trees of different DBH (diameter at breast height)? How much carbon potential possessed by dominant species of these forests? How vegetation carbon is distributed in these forests? Which species shows high carbon sequestration? What are the physiochemical properties of soil in these forests? Five-year (2005-2010) tree growth data from permanently established plots in the AMNR was analysed for species composition, density, stem diameter (DBH), height and carbon (C) density both in aboveground and belowground vegetation biomass. Our study indicated that among two comparative sites, overall 54 species of 16 different families were present. The stem density, height, C density and soil properties varied significantly with time among the sites showing uneven distribution across the forests. Among the dominant species, L. xylocarpus represents 30% of the total carbon on site 1 while C. wattii represents 50% of the total carbon on site 2. The average C density ranged from 176.35 to 243.97 t C ha(-1). The study emphasized that there is generous degree to expand the carbon stocking in this AMNR through scientific management gearing towards conservation of old trees and planting of potentially high carbon sequestering species on good site quality areas.

  5. Effects of LiDAR point density and landscape context on estimates of urban forest biomass

    NASA Astrophysics Data System (ADS)

    Singh, Kunwar K.; Chen, Gang; McCarter, James B.; Meentemeyer, Ross K.

    2015-03-01

    Light Detection and Ranging (LiDAR) data is being increasingly used as an effective alternative to conventional optical remote sensing to accurately estimate aboveground forest biomass ranging from individual tree to stand levels. Recent advancements in LiDAR technology have resulted in higher point densities and improved data accuracies accompanied by challenges for procuring and processing voluminous LiDAR data for large-area assessments. Reducing point density lowers data acquisition costs and overcomes computational challenges for large-area forest assessments. However, how does lower point density impact the accuracy of biomass estimation in forests containing a great level of anthropogenic disturbance? We evaluate the effects of LiDAR point density on the biomass estimation of remnant forests in the rapidly urbanizing region of Charlotte, North Carolina, USA. We used multiple linear regression to establish a statistical relationship between field-measured biomass and predictor variables derived from LiDAR data with varying densities. We compared the estimation accuracies between a general Urban Forest type and three Forest Type models (evergreen, deciduous, and mixed) and quantified the degree to which landscape context influenced biomass estimation. The explained biomass variance of the Urban Forest model, using adjusted R2, was consistent across the reduced point densities, with the highest difference of 11.5% between the 100% and 1% point densities. The combined estimates of Forest Type biomass models outperformed the Urban Forest models at the representative point densities (100% and 40%). The Urban Forest biomass model with development density of 125 m radius produced the highest adjusted R2 (0.83 and 0.82 at 100% and 40% LiDAR point densities, respectively) and the lowest RMSE values, highlighting a distance impact of development on biomass estimation. Our evaluation suggests that reducing LiDAR point density is a viable solution to regional

  6. Reclamation of coppice forests in order to increase the potential of woody biomass in Serbia

    NASA Astrophysics Data System (ADS)

    Bjelanovic, I.; Krstic, M.

    2012-04-01

    Biomass makes 63% of the total renewable energy potential of Serbia. Here, the biomass from forests together with wood processing industry waste represent the second most important renewable source for energy production. The Action Plan for Biomass of Serbia (2010) shows that the technically exploitable biomass in the Republic of Serbia amounts annually 2.7 Mtoe. Here, the woody biomass (fuelwood, forest residue, wood processing industry residue, wood from trees outside the forest) accounts for 1.0 Mtoe while the rest originates from agricultural sources. According to the national forest inventory (2008), forest cover in Serbia accounts for 29% of the country area, having standing volume of 362.5 mil. m3 and annual increment of 9.1 mil. m3. More than half is state-owned and the rest 47% is in the private ownership. Coppice forests dominate in the forest stock (65%). According to Glavonjić (2010), northeastern and southwestern Serbia are the regions with greatest spatial forest distribution. The general forest condition is characterised by insufficient production volume, unsatisfactory stock density and forest cover, high percentage of degraded forests, unfavorable age structure, unfavorable health condition and weeded areas. Herewith, the basic measures for the improvement of forest fund (Forestry Development Strategy for Serbia, 2006) represent conversion of coppice forests, increase of forest cover and productivity of forest ecosystems by the ecologically, economically and socially acceptable methods. The actions include reclamation of degraded forests, re- and afforestation activities on abandoned agricultural, degraded and other treeless lands. The average standing volume of high forests is 254 m3·ha-1 with an annual increment of 5.5 m3·ha-1. On the contrary, coppice forests dispose 124 m3·ha-1 of standing volume, having an annual increment of 3.1 m3·ha-1. Here, estimated losses from coppice forests amount up to 3.5 mil. m3 wood annually. These data

  7. Shifts in biomass and productivity for a subtropical dry forest in response to simulated elevated hurricane disturbances

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

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

  8. Thresholds of logging intensity to maintain tropical forest biodiversity.

    PubMed

    Burivalova, Zuzana; Sekercioğlu, Cağan Hakkı; Koh, Lian Pin

    2014-08-18

    Primary tropical forests are lost at an alarming rate, and much of the remaining forest is being degraded by selective logging. Yet, the impacts of logging on biodiversity remain poorly understood, in part due to the seemingly conflicting findings of case studies: about as many studies have reported increases in biodiversity after selective logging as have reported decreases. Consequently, meta-analytical studies that treat selective logging as a uniform land use tend to conclude that logging has negligible effects on biodiversity. However, selectively logged forests might not all be the same. Through a pantropical meta-analysis and using an information-theoretic approach, we compared and tested alternative hypotheses for key predictors of the richness of tropical forest fauna in logged forest. We found that the species richness of invertebrates, amphibians, and mammals decreases as logging intensity increases and that this effect varies with taxonomic group and continental location. In particular, mammals and amphibians would suffer a halving of species richness at logging intensities of 38 m(3) ha(-1) and 63 m(3) ha(-1), respectively. Birds exhibit an opposing trend as their total species richness increases with logging intensity. An analysis of forest bird species, however, suggests that this pattern is largely due to an influx of habitat generalists into heavily logged areas while forest specialist species decline. Our study provides a quantitative analysis of the nuanced responses of species along a gradient of logging intensity, which could help inform evidence-based sustainable logging practices from the perspective of biodiversity conservation.

  9. Tree diversity, composition, forest structure and aboveground biomass dynamics after single and repeated fire in a Bornean rain forest.

    PubMed

    Slik, J W Ferry; Bernard, Caroline S; Van Beek, Marloes; Breman, Floris C; Eichhorn, Karl A O

    2008-12-01

    Forest fires remain a devastating phenomenon in the tropics that not only affect forest structure and biodiversity, but also contribute significantly to atmospheric CO2. Fire used to be extremely rare in tropical forests, leaving ample time for forests to regenerate to pre-fire conditions. In recent decades, however, tropical forest fires occur more frequently and at larger spatial scales than they used to. We studied forest structure, tree species diversity, tree species composition, and aboveground biomass during the first 7 years since fire in unburned, once burned and twice burned forest of eastern Borneo to determine the rate of recovery of these forests. We paid special attention to changes in the tree species composition during burned forest regeneration because we expect the long-term recovery of aboveground biomass and ecosystem functions in burned forests to largely depend on the successful regeneration of the pre-fire, heavy-wood, species composition. We found that forest structure (canopy openness, leaf area index, herb cover, and stem density) is strongly affected by fire but shows quick recovery. However, species composition shows no or limited recovery and aboveground biomass, which is greatly reduced by fire, continues to be low or decline up to 7 years after fire. Consequently, large amounts of the C released to the atmosphere by fire will not be recaptured by the burned forest ecosystem in the near future. We also observed that repeated fire, with an inter-fire interval of 15 years, does not necessarily lead to a huge deterioration in the regeneration potential of tropical forest. We conclude that burned forests are valuable and should be conserved and that long-term monitoring programs in secondary forests are necessary to determine their recovery rates, especially in relation to aboveground biomass accumulation.

  10. Methods for Determining Nonmerchantable Forest Biomass Yields for Use as Fuel.

    DTIC Science & Technology

    1980-07-19

    Construction Engineering Research Laboratory) and the Army’s Biomass Energy Program. 2.0 METHODOLOGY Telephone contacts were made with local, state...Forest biomass is a logical energy source. To consider major capital expenditures for conversion to a wood/ biomass energy source, a necessary step

  11. Biogeographical patterns of biomass allocation in leaves, stems, and roots in China's forests.

    PubMed

    Zhang, Hao; Wang, Kelin; Xu, Xianli; Song, Tongqing; Xu, Yanfang; Zeng, Fuping

    2015-11-03

    To test whether there are general patterns in biomass partitioning in relation to environmental variation when stand biomass is considered, we investigated biomass allocation in leaves, stems, and roots in China's forests using both the national forest inventory data (2004-2008) and our field measurements (2011-2012). Distribution patterns of leaf, stem, and root biomass showed significantly different trends according to latitude, longitude, and altitude, and were positively and significantly correlated with stand age and mean annual precipitation. Trade-offs among leaves, stems, and roots varied with forest type and origin and were mainly explained by stand biomass. Based on the constraints of stand biomass, biomass allocation was also influenced by forest type, origin, stand age, stand density, mean annual temperature, precipitation, and maximum temperature in the growing season. Therefore, after stand biomass was accounted for, the residual variation in biomass allocation could be partially explained by stand characteristics and environmental factors, which may aid in quantifying carbon cycling in forest ecosystems and assessing the impacts of climate change on forest carbon dynamics in China.

  12. Biogeographical patterns of biomass allocation in leaves, stems, and roots in China’s forests

    PubMed Central

    Zhang, Hao; Wang, Kelin; Xu, Xianli; Song, Tongqing; Xu, Yanfang; Zeng, Fuping

    2015-01-01

    To test whether there are general patterns in biomass partitioning in relation to environmental variation when stand biomass is considered, we investigated biomass allocation in leaves, stems, and roots in China’s forests using both the national forest inventory data (2004–2008) and our field measurements (2011–2012). Distribution patterns of leaf, stem, and root biomass showed significantly different trends according to latitude, longitude, and altitude, and were positively and significantly correlated with stand age and mean annual precipitation. Trade-offs among leaves, stems, and roots varied with forest type and origin and were mainly explained by stand biomass. Based on the constraints of stand biomass, biomass allocation was also influenced by forest type, origin, stand age, stand density, mean annual temperature, precipitation, and maximum temperature in the growing season. Therefore, after stand biomass was accounted for, the residual variation in biomass allocation could be partially explained by stand characteristics and environmental factors, which may aid in quantifying carbon cycling in forest ecosystems and assessing the impacts of climate change on forest carbon dynamics in China. PMID:26525117

  13. Linking disturbance intensity and carbon cycle in forest ecosystems

    NASA Astrophysics Data System (ADS)

    Gielen, B.; Hudiburg, T.; Law, B. E.; Luyssaert, S.

    2011-12-01

    There is increasing awareness that natural and anthropogenic disturbance in forests forest affects exchange of CO2, H2O and energy between the ecosystem and the atmosphere. Furthermore, severe disturbance may result in substantial emissions of greenhouse gasses to the atmosphere. Consequently quantification of land use and disturbance intensity (LUDI) is one of the next steps needed to improve our understanding of the carbon cycle, its interactions with the atmosphere and its main drivers at local as well as at global level. The conventional NPP-based approaches to quantify the intensity of land management are limited because they lack a sound ecological basis. Here we apply a new way of characterising the degree of management and disturbance in forest. The index called LUDI: land use and disturbance intensity makes use of the self thinning theory and observations of diameter at breast height and stand density. The application of LUDI was demonstrated by using a very extensive dataset from the Pacific Northwest region (PNW) in North America containing more than 5000 inventory plots. Results show significant relationships between LUDI and forest productivity (NPP) and Carbon uptake (NEP) for seven different forest types in the PNW. In addition the relationships suggest a maximal productivity at mild disturbance. These results further confirm the link between forest disturbance and carbon cycling in forest ecosystems.

  14. Re-evaluation of forest biomass carbon stocks and lessons from the world's most carbon-dense forests.

    PubMed

    Keith, Heather; Mackey, Brendan G; Lindenmayer, David B

    2009-07-14

    From analysis of published global site biomass data (n = 136) from primary forests, we discovered (i) the world's highest known total biomass carbon density (living plus dead) of 1,867 tonnes carbon per ha (average value from 13 sites) occurs in Australian temperate moist Eucalyptus regnans forests, and (ii) average values of the global site biomass data were higher for sampled temperate moist forests (n = 44) than for sampled tropical (n = 36) and boreal (n = 52) forests (n is number of sites per forest biome). Spatially averaged Intergovernmental Panel on Climate Change biome default values are lower than our average site values for temperate moist forests, because the temperate biome contains a diversity of forest ecosystem types that support a range of mature carbon stocks or have a long land-use history with reduced carbon stocks. We describe a framework for identifying forests important for carbon storage based on the factors that account for high biomass carbon densities, including (i) relatively cool temperatures and moderately high precipitation producing rates of fast growth but slow decomposition, and (ii) older forests that are often multiaged and multilayered and have experienced minimal human disturbance. Our results are relevant to negotiations under the United Nations Framework Convention on Climate Change regarding forest conservation, management, and restoration. Conserving forests with large stocks of biomass from deforestation and degradation avoids significant carbon emissions to the atmosphere, irrespective of the source country, and should be among allowable mitigation activities. Similarly, management that allows restoration of a forest's carbon sequestration potential also should be recognized.

  15. Use of forest inventories and geographic information systems to estimate biomass density of tropical forests: Application to tropical Africa.

    PubMed

    Brown, S; Gaston, G

    1995-01-01

    One of the most important databases needed for estimating emissions of carbon dioxide resulting from changes in the cover, use, and management of tropical forests is the total quantity of biomass per unit area, referred to as biomass density. Forest inventories have been shown to be valuable sources of data for estimating biomass density, but inventories for the tropics are few in number and their quality is poor. This lack of reliable data has been overcome by use of a promising approach that produces geographically referenced estimates by modeling in a geographic information system (GIS). This approach has been used to produce geographically referenced, spatial distributions of potential and actual (circa 1980) aboveground biomass density of all forests types in tropical Africa. Potential and actual biomass density estimates ranged from 33 to 412 Mg ha(-1) (10(6)g ha(-1)) and 20 to 299 Mg ha(-1), respectively, for very dry lowland to moist lowland forests and from 78 to 197 Mg ha(-1) and 37 to 105 Mg ha(-1), respectively, for montane-seasonal to montane-moist forests. Of the 37 countries included in this study, more than half (51%) contained forests that had less than 60% of their potential biomass. Actual biomass density for forest vegetation was lowest in Botswana, Niger, Somalia, and Zimbabwe (about 10 to 15 Mg ha(-1)). Highest estimates for actual biomass density were found in Congo, Equatorial Guinea, Gabon, and Liberia (305 to 344 Mg ha(-1)). Results from this research effort can contribute to reducing uncertainty in the inventory of country-level emission by providing consistent estimates of biomass density at subnational scales that can be used with other similarly scaled databases on change in land cover and use.

  16. Increase in carbon emissions from forest fires after intensive reforestation and forest management programs.

    PubMed

    Choi, Sung-Deuk; Chang, Yoon-Seok; Park, Byung-Kwon

    2006-12-15

    This paper shows an example of substantial increase in carbon emissions from forest fires after reforestation on a national scale. It is the first estimation of historical carbon emissions from forest fires in Korea during the last 40 years. Investigation was focused on the recent increase in large forest fires and its closely related factors. A simple modeling approach to estimate carbon emission was applied. The direct carbon emission from forest fires in 2000, ranging from 115 to 300 Gg C, corresponds to 1-3% of the annual carbon uptake by forests. The influence of forest fires on the carbon cycle in Korea is not so significant, but Korean forests have a large potential for generating severe local fires due to increasing forest carbon density and a high forest area ratio (forest area/total land area) of 65%. The carbon emission per area burned (Mg C ha(-1)) clearly reflects the trend toward increases in the number of severe fires. Statistical analyses and the trends of annual temperature and precipitation show that the recent large increase in carbon emissions may be the negative consequences of intensive forest regrowth that is the product of successful reforestation and forest management programs rather than the effect of climate change. These results imply a need for further studies in other countries, where large-scale plantation has been conducted, to evaluate the role of plantation and forest fires on the global carbon cycle.

  17. Large-area Mapping of Forest Cover and Biomass using ALOS PALSAR

    NASA Astrophysics Data System (ADS)

    Cartus, O.; Kellndorfer, J. M.; Walker, W. S.; Goetz, S. J.; Laporte, N.; Bishop, J.; Cormier, T.; Baccini, A.

    2011-12-01

    In the frame of a Pantropical mapping project, we aim at producing high-resolution forest cover maps from ALOS PALSAR. The ALOS data was obtained through the Americas ALOS Data Node (AADN) at ASF. For the forest cover classification, a pan-tropical network of calibrated reference data was generated from ancillary satellite data (ICESAT GLAS). These data are used to classify PALSAR swath data to be combined to continental forest probability maps. The maps are validated with withheld training data for testing, as well as through independent operator verification with very high-resolution image. In addition, we aim at developing robust algorithms for the mapping of forest biophysical parameters like stem volume or biomass using synergy of PALSAR, optical and Lidar data. Currently we are testing different approaches for the mapping of forest biophysical parameters. 1) For the showcase scenario of Mexico, where we have access to ~1400 PALSAR FBD images as well as the 30 m Landsat Vegetation Continuous Field product, VCF, we test a traditional ground-data based approach. The PALSAR HH/HV intensity data and VCF are used as predictor layers in RandomForest for predicting aboveground forest biomass. A network of 40000 in situ biomass plots is used for model development (for each PALSAR swath) as well as for validation. With this approach a first 30 m biomass map for entire Mexico was produced. An initial validation of the map resulted in an RMSE of 41 t/ha and an R2 of 0.42. Pronounced differences between different ecozones were observed. In some areas the retrieval reached an R2 of 0.6 (e.g. pine-oak forests) whereas, for instance, in dry woodlands, the retrieval accuracy was much lower (R2 of 0.1). A major limitation of the approach was also represented by the fact that for the development of models for each ALOS swath, in some cases too few sample plots were available. 2) Chile: At a forest site in Central Chile, dominated by plantations of pinus radiata, synergy of ALOS

  18. Tree biomass in the Swiss landscape: nationwide modelling for improved accounting for forest and non-forest trees.

    PubMed

    Price, B; Gomez, A; Mathys, L; Gardi, O; Schellenberger, A; Ginzler, C; Thürig, E

    2017-03-01

    Trees outside forest (TOF) can perform a variety of social, economic and ecological functions including carbon sequestration. However, detailed quantification of tree biomass is usually limited to forest areas. Taking advantage of structural information available from stereo aerial imagery and airborne laser scanning (ALS), this research models tree biomass using national forest inventory data and linear least-square regression and applies the model both inside and outside of forest to create a nationwide model for tree biomass (above ground and below ground). Validation of the tree biomass model against TOF data within settlement areas shows relatively low model performance (R (2) of 0.44) but still a considerable improvement on current biomass estimates used for greenhouse gas inventory and carbon accounting. We demonstrate an efficient and easily implementable approach to modelling tree biomass across a large heterogeneous nationwide area. The model offers significant opportunity for improved estimates on land use combination categories (CC) where tree biomass has either not been included or only roughly estimated until now. The ALS biomass model also offers the advantage of providing greater spatial resolution and greater within CC spatial variability compared to the current nationwide estimates.

  19. Forest biomass variation in Southernmost Brazil: the impact of Araucaria trees.

    PubMed

    Rosenfield, Milena Fermina; Souza, Alexandre F

    2014-03-01

    A variety of environmental and biotic factors determine vegetation growth and affect plant biomass accumulation. From temperature to species composition, aboveground biomass storage in forest ecosystems is influenced by a number of variables and usually presents a high spatial variability. With this focus, the aim of the study was to evaluate the variables affecting live aboveground forest biomass (AGB) in Subtropical Moist Forests of Southern Brazil, and to analyze the spatial distribution of biomass estimates. Data from a forest inventory performed in the State of Rio Grande do Sul, Southern Brazil, was used in the present study. Thirty-eight 1-ha plots were sampled and all trees with DBH > or = 9.5cm were included for biomass estimation. Values for aboveground biomass were obtained using published allometric equations. Environmental and biotic variables (elevation, rainfall, temperature, soils, stem density and species diversity) were obtained from the literature or calculated from the dataset. For the total dataset, mean AGB was 195.2 Mg/ha. Estimates differed between Broadleaf and Mixed Coniferous-Broadleaf forests: mean AGB was lower in Broadleaf Forests (AGB(BF)=118.9 Mg/ha) when compared to Mixed Forests (AGB(MF)=250.3 Mg/ha). There was a high spatial and local variability in our dataset, even within forest types. This condition is normal in tropical forests and is usually attributed to the presence of large trees. The explanatory multiple regressions were influenced mainly by elevation and explained 50.7% of the variation in AGB. Stem density, diversity and organic matter also influenced biomass variation. The results from our study showed a positive relationship between aboveground biomass and elevation. Therefore, higher values of AGB are located at higher elevations and subjected to cooler temperatures and wetter climate. There seems to be an important contribution of the coniferous species Araucaria angustifolia in Mixed Forest plots, as it presented

  20. Forest above ground biomass estimation and forest/non-forest classification for Odisha, India, using L-band Synthetic Aperture Radar (SAR) data

    NASA Astrophysics Data System (ADS)

    Suresh, M.; Kiran Chand, T. R.; Fararoda, R.; Jha, C. S.; Dadhwal, V. K.

    2014-11-01

    Tropical forests contribute to approximately 40 % of the total carbon found in terrestrial biomass. In this context, forest/non-forest classification and estimation of forest above ground biomass over tropical regions are very important and relevant in understanding the contribution of tropical forests in global biogeochemical cycles, especially in terms of carbon pools and fluxes. Information on the spatio-temporal biomass distribution acts as a key input to Reducing Emissions from Deforestation and forest Degradation Plus (REDD+) action plans. This necessitates precise and reliable methods to estimate forest biomass and to reduce uncertainties in existing biomass quantification scenarios. The use of backscatter information from a host of allweather capable Synthetic Aperture Radar (SAR) systems during the recent past has demonstrated the potential of SAR data in forest above ground biomass estimation and forest / nonforest classification. In the present study, Advanced Land Observing Satellite (ALOS) / Phased Array L-band Synthetic Aperture Radar (PALSAR) data along with field inventory data have been used in forest above ground biomass estimation and forest / non-forest classification over Odisha state, India. The ALOSPALSAR 50 m spatial resolution orthorectified and radiometrically corrected HH/HV dual polarization data (digital numbers) for the year 2010 were converted to backscattering coefficient images (Schimada et al., 2009). The tree level measurements collected during field inventory (2009-'10) on Girth at Breast Height (GBH at 1.3 m above ground) and height of all individual trees at plot (plot size 0.1 ha) level were converted to biomass density using species specific allometric equations and wood densities. The field inventory based biomass estimations were empirically integrated with ALOS-PALSAR backscatter coefficients to derive spatial forest above ground biomass estimates for the study area. Further, The Support Vector Machines (SVM) based Radial

  1. 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

  2. Biomass Burning:Significant Source of Nitrate and Sulfate for the Andean Rain Forest in Ecuador

    NASA Astrophysics Data System (ADS)

    Fabian, P.; Rollenbeck, R.; Spichtinger, N.

    2009-04-01

    Forest fires are significant sources of carbon, sulfur and nitrogen compounds which, along with their photochemically generated reaction products, can be transported over very long distances, even traversing oceans. Chemical analyses of rain and fogwater samples collected on the wet eastern slopes of the Ecuadorian Andes show frequent episodes of high sulfate and nitrate concentration, from which annual deposition rates of about14 kg/ha and 7 kg/ha ,respectively, are derived. These are comparable to those observed in polluted central Europe. Regular rain and fogwater sampling along an altitude profile between 1800 and 3185 m, has been carried out since 2002.The research area located at 30 58'S ,790 5' W is dominated by trade winds from easterly directions. The samples, generally accumulated over 1-week intervals, were analysed for pH, conductivity and major ions(K+,Na+,NH4+,Ca2+,Mg 2+,SO42-,NO3-,PO43-).For all components a strong seasonal variation is observed, while the altitudinal gradient is less pronounced. About 65 % of the weekly samples were significantly loaded with cations and anions, with pH often as low 3.5 to 4.0 and conductivity up to 50 uS/cm. Back trajectories (FLEXTRA) showed that respective air masses had passed over areas of intense biomass burning, sometimes influenced by volcanoes, ocean spray, or even episodic Sahara and/or Namib desert dust interference not discussed here. Enhanced SO4 2-and NO3- were identified, by combining satellite-based fire pixels with back trajectories, as predominantly resulting from biomass burning. For most cases, by using emission inventories, anthropogenic precursor sources other than forest fires play a minor role, thus leaving biomass burning as the main source of nitrate and sulphate in rain and fogwater. Some SO4 2- , about 10 % of the total input, could be identified to originate from active volcanoes, whose plumes were sometimes encountered by the respective back trajectories. While volcanic, oceanic and

  3. Interactive effects of frequent burning and timber harvesting on above ground carbon biomass in temperate eucalypt forests

    NASA Astrophysics Data System (ADS)

    Collins, Luke; Penman, Trent; Ximenes, Fabiano; Bradstock, Ross

    2015-04-01

    The sequestration of carbon has been identified as an important strategy to mitigate the effects of climate change. Fuel reduction burning and timber harvesting are two common co-occurring management practices within forests. Frequent burning and timber harvesting may alter forest carbon pools through the removal and redistribution of biomass and demographic and structural changes to tree communities. Synergistic and antagonistic interactions between frequent burning and harvesting are likely to occur, adding further complexity to the management of forest carbon stocks. Research aimed at understanding the interactive effects of frequent fire and timber harvesting on carbon biomass is lacking. This study utilised data from two long term (25 - 30 years) manipulative burning experiments conducted in southern Australia in temperate eucalypt forests dominated by resprouting canopy species. Specifically we examined the effect of fire frequency and harvesting on (i) total biomass of above ground carbon pools and (ii) demographic and structural characteristics of live trees. We also investigated some of the mechanisms driving these changes. Frequent burning reduced carbon biomass by up to 20% in the live tree carbon pool. Significant interactions occurred between fire and harvesting, whereby the reduction in biomass of trees >20 cm diameter breast height (DBH) was amplified by increased fire frequency. The biomass of trees <20 cm DBH increased with harvesting intensity in frequently burnt areas, but was unaffected by harvesting intensity in areas experiencing low fire frequency. Biomass of standing and fallen coarse woody debris was relatively unaffected by logging and fire frequency. Fire and harvesting significantly altered stand structure over the study period. Comparison of pre-treatment conditions to current conditions revealed that logged sites had a significantly greater increase in the number of small trees (<40 cm DBH) than unlogged sites. Logged sites showed a

  4. Forest Management Intensity Affects Aquatic Communities in Artificial Tree Holes

    PubMed Central

    Petermann, Jana S.; Rohland, Anja; Sichardt, Nora; Lade, Peggy; Guidetti, Brenda; Weisser, Wolfgang W.; Gossner, Martin M.

    2016-01-01

    Forest management could potentially affect organisms in all forest habitats. However, aquatic communities in water-filled tree-holes may be especially sensitive because of small population sizes, the risk of drought and potential dispersal limitation. We set up artificial tree holes in forest stands subject to different management intensities in two regions in Germany and assessed the influence of local environmental properties (tree-hole opening type, tree diameter, water volume and water temperature) as well as regional drivers (forest management intensity, tree-hole density) on tree-hole insect communities (not considering other organisms such as nematodes or rotifers), detritus content, oxygen and nutrient concentrations. In addition, we compared data from artificial tree holes with data from natural tree holes in the same area to evaluate the methodological approach of using tree-hole analogues. We found that forest management had strong effects on communities in artificial tree holes in both regions and across the season. Abundance and species richness declined, community composition shifted and detritus content declined with increasing forest management intensity. Environmental variables, such as tree-hole density and tree diameter partly explained these changes. However, dispersal limitation, indicated by effects of tree-hole density, generally showed rather weak impacts on communities. Artificial tree holes had higher water temperatures (on average 2°C higher) and oxygen concentrations (on average 25% higher) than natural tree holes. The abundance of organisms was higher but species richness was lower in artificial tree holes. Community composition differed between artificial and natural tree holes. Negative management effects were detectable in both tree-hole systems, despite their abiotic and biotic differences. Our results indicate that forest management has substantial and pervasive effects on tree-hole communities and may alter their structure and

  5. Forest Management Intensity Affects Aquatic Communities in Artificial Tree Holes.

    PubMed

    Petermann, Jana S; Rohland, Anja; Sichardt, Nora; Lade, Peggy; Guidetti, Brenda; Weisser, Wolfgang W; Gossner, Martin M

    2016-01-01

    Forest management could potentially affect organisms in all forest habitats. However, aquatic communities in water-filled tree-holes may be especially sensitive because of small population sizes, the risk of drought and potential dispersal limitation. We set up artificial tree holes in forest stands subject to different management intensities in two regions in Germany and assessed the influence of local environmental properties (tree-hole opening type, tree diameter, water volume and water temperature) as well as regional drivers (forest management intensity, tree-hole density) on tree-hole insect communities (not considering other organisms such as nematodes or rotifers), detritus content, oxygen and nutrient concentrations. In addition, we compared data from artificial tree holes with data from natural tree holes in the same area to evaluate the methodological approach of using tree-hole analogues. We found that forest management had strong effects on communities in artificial tree holes in both regions and across the season. Abundance and species richness declined, community composition shifted and detritus content declined with increasing forest management intensity. Environmental variables, such as tree-hole density and tree diameter partly explained these changes. However, dispersal limitation, indicated by effects of tree-hole density, generally showed rather weak impacts on communities. Artificial tree holes had higher water temperatures (on average 2°C higher) and oxygen concentrations (on average 25% higher) than natural tree holes. The abundance of organisms was higher but species richness was lower in artificial tree holes. Community composition differed between artificial and natural tree holes. Negative management effects were detectable in both tree-hole systems, despite their abiotic and biotic differences. Our results indicate that forest management has substantial and pervasive effects on tree-hole communities and may alter their structure and

  6. 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.

  7. Harvesting forest biomass for energy in Minnesota: An assessment of guidelines, costs and logistics

    NASA Astrophysics Data System (ADS)

    Saleh, Dalia El Sayed Abbas Mohamed

    The emerging market for renewable energy in Minnesota has generated a growing interest in utilizing more forest biomass for energy. However, this growing interest is paralleled with limited knowledge of the environmental impacts and cost effectiveness of utilizing this resource. To address environmental and economic viability concerns, this dissertation has addressed three areas related to biomass harvest: First, existing biomass harvesting guidelines and sustainability considerations are examined. Second, the potential contribution of biomass energy production to reduce the costs of hazardous fuel reduction treatments in these trials is assessed. Third, the logistics of biomass production trials are analyzed. Findings show that: (1) Existing forest related guidelines are not sufficient to allow large-scale production of biomass energy from forest residue sustainably. Biomass energy guidelines need to be based on scientific assessments of how repeated and large scale biomass production is going to affect soil, water and habitat values, in an integrated and individual manner over time. Furthermore, such guidelines would need to recommend production logistics (planning, implementation, and coordination of operations) necessary for a potential supply with the least site and environmental impacts. (2) The costs of biomass production trials were assessed and compared with conventional treatment costs. In these trials, conventional mechanical treatment costs were lower than biomass energy production costs less income from biomass sale. However, a sensitivity analysis indicated that costs reductions are possible under certain site, prescriptions and distance conditions. (3) Semi-structured interviews with forest machine operators indicate that existing fuel reduction prescriptions need to be more realistic in making recommendations that can overcome operational barriers (technical and physical) and planning and coordination concerns (guidelines and communications

  8. POLINSAR Coherence-Based Regression Analysis of Forest Biomass Using RADARSAT-2 Datasets

    NASA Astrophysics Data System (ADS)

    Singh, J.; Kumar, S.; Kushwaha, S. P. S.

    2014-11-01

    Forests play a pivotal role in synchronizing earth's carbon cycle by absorbing carbon from the atmosphere and storing it in the form of biomass. Researchers today are trying to understand the climatic variations, especially those occurring due to destruction of forest and its corresponding biomass loss. Hence, quantification of various forest parameters such as biomass is imperative for evaluating the carbon. The objective of this research was to exploit the potential of C-band Radarsat-2 Polarimetric Interferometric Synthetic Aperture Radar (PolInSAR) technique for analysing the relationship between complex coherence and field-estimated aboveground biomass. Association between the backscatter and the aboveground biomass was also established in the process. To serve our objective, Radarsat-2 interferometric pair dated 4th March, 2013 (master image) and 28th March, 2013 (slave image) were procured for the Barkot Reserve Forest region of Dehradun, India. Field sampling was done for 30 plots (31.62 m x 31.62 m) and stem diameter and tree height were measured in each plot. The study emphasized on the application of POLINSAR coherence instead of using conventional method of relying on backscatter values for retrieving forest biomass. Coherence matrices were utilized for generating complex coherence values for different polarization channels and were regressed against field estimated aboveground biomass. Results indicated a negative linear relationship between complex coherence and aboveground biomass with the cross - polarized coherence showing the highest R2 value of 0.71. Further, the backscatter mechanism when studied with respect to aboveground biomass indicated a positive linear relationship between backscatter values and field estimated aboveground biomass with R2 value of 0.45 and 0.61 for slave and master image respectively. The results suggest that PolInSAR technique, in combination with different modelling approaches, can be adopted for estimating forest

  9. Aerosol emissions by tropical forest and savanna biomass burning: Characteristic trace elements and fluxes

    SciTech Connect

    Echalar, F.; Gaudichet, A.; Cachier, H.

    1995-11-15

    This report characterizes and compares trace element emissions from fires of three different types of savannas and from the southwestern amazonian rain forest. This study tries to verify a fingerprint that may characterize savanna fires or tropical biomass burning.

  10. Effects of increased biomass removal on the biogeochemistry of two Norwegian forest ecosystems

    NASA Astrophysics Data System (ADS)

    Lange, H.; Clarke, N.; Kjønaas, O. J.; Aas, W.; Andreassen, K.; Børja, I.; Bratli, H.; Eich-Greatorex, S.; Eldhuset, T.; Holt-Hanssen, K.

    2009-04-01

    Increased removal of biomass from forested ecosystems for use as an alternative source of energy is an option in several countries. E.g., it is planned to double the use of bioenergy from all sources until 2020 in Norway. A large fraction of this increase is coming from forest resources, e.g. by removing harvest residues like branches and tops. This removal will reduce the supply of nutrients and organic matter to the forest soil, and may in the longer term increase the risk for future nutrient imbalance, soil erosion on steep slopes, reduced forest production, and changes in biodiversity and ground vegetation species composition. However, field experiments so far have found contrasting results in this respect. Soil effects of increased biomass removal will be closely related to soil organic matter (SOM) dynamics, litter quality, and turnover rates. Harvest intensity may affect the decomposition of existing SOM as well as the build-up of new SOM from litter and forest residues, by changing factors like soil temperature and moisture as well as amount and type of litter input. Changes in input of litter with different nutrient concentrations and decomposition patterns along with changes in SOM decomposition will affect the total storage of carbon, nitrogen and other vital nutrients in the soil. In the context of a Norwegian research project started in 2009, we will quantify how different harvesting regimes lead to different C addition to soil, and determine which factors have the greatest effect on decomposition of SOM under different environmental conditions. Two Norway spruce forest ecosystems will be investigated, one in eastern and one in western Norway, representing different climatic conditions and landscape types. At each location, two treatment regimes will be tested: (1) conventional harvesting (CH), with residues left on-site, and (2) aboveground whole-tree harvest (WTH), with branches, needles, and tops removed. Input of different forest residues will be

  11. Relating multifrequency radar backscattering to forest biomass: Modeling and AIRSAR measurement

    NASA Technical Reports Server (NTRS)

    Sun, Guo-Qing; Ranson, K. Jon

    1992-01-01

    During the last several years, significant efforts in microwave remote sensing were devoted to relating forest parameters to radar backscattering coefficients. These and other studies showed that in most cases, the longer wavelength (i.e. P band) and cross-polarization (HV) backscattering had higher sensitivity and better correlation to forest biomass. This research examines this relationship in a northern forest area through both backscatter modeling and synthetic aperture radar (SAR) data analysis. The field measurements were used to estimate stand biomass from forest weight tables. The backscatter model described by Sun et al. was modified to simulate the backscattering coefficients with respect to stand biomass. The average number of trees per square meter or radar resolution cell, and the average tree height or diameter breast height (dbh) in the forest stand are the driving parameters of the model. The rest of the soil surface, orientation, and size distributions of leaves and branches, remain unchanged in the simulations.

  12. Amazonian landscapes and the bias in field studies of forest structure and biomass

    PubMed Central

    Marvin, David C.; Asner, Gregory P.; Knapp, David E.; Anderson, Christopher B.; Martin, Roberta E.; Sinca, Felipe; Tupayachi, Raul

    2014-01-01

    Tropical forests convert more atmospheric carbon into biomass each year than any terrestrial ecosystem on Earth, underscoring the importance of accurate tropical forest structure and biomass maps for the understanding and management of the global carbon cycle. Ecologists have long used field inventory plots as the main tool for understanding forest structure and biomass at landscape-to-regional scales, under the implicit assumption that these plots accurately represent their surrounding landscape. However, no study has used continuous, high-spatial-resolution data to test whether field plots meet this assumption in tropical forests. Using airborne LiDAR (light detection and ranging) acquired over three regions in Peru, we assessed how representative a typical set of field plots are relative to their surrounding host landscapes. We uncovered substantial mean biases (9–98%) in forest canopy structure (height, gaps, and layers) and aboveground biomass in both lowland Amazonian and montane Andean landscapes. Moreover, simulations reveal that an impractical number of 1-ha field plots (from 10 to more than 100 per landscape) are needed to develop accurate estimates of aboveground biomass at landscape scales. These biases should temper the use of plots for extrapolations of forest dynamics to larger scales, and they demonstrate the need for a fundamental shift to high-resolution active remote sensing techniques as a primary sampling tool in tropical forest biomass studies. The potential decrease in the bias and uncertainty of remotely sensed estimates of forest structure and biomass is a vital step toward successful tropical forest conservation and climate-change mitigation policy. PMID:25422434

  13. Amazonian landscapes and the bias in field studies of forest structure and biomass.

    PubMed

    Marvin, David C; Asner, Gregory P; Knapp, David E; Anderson, Christopher B; Martin, Roberta E; Sinca, Felipe; Tupayachi, Raul

    2014-12-02

    Tropical forests convert more atmospheric carbon into biomass each year than any terrestrial ecosystem on Earth, underscoring the importance of accurate tropical forest structure and biomass maps for the understanding and management of the global carbon cycle. Ecologists have long used field inventory plots as the main tool for understanding forest structure and biomass at landscape-to-regional scales, under the implicit assumption that these plots accurately represent their surrounding landscape. However, no study has used continuous, high-spatial-resolution data to test whether field plots meet this assumption in tropical forests. Using airborne LiDAR (light detection and ranging) acquired over three regions in Peru, we assessed how representative a typical set of field plots are relative to their surrounding host landscapes. We uncovered substantial mean biases (9-98%) in forest canopy structure (height, gaps, and layers) and aboveground biomass in both lowland Amazonian and montane Andean landscapes. Moreover, simulations reveal that an impractical number of 1-ha field plots (from 10 to more than 100 per landscape) are needed to develop accurate estimates of aboveground biomass at landscape scales. These biases should temper the use of plots for extrapolations of forest dynamics to larger scales, and they demonstrate the need for a fundamental shift to high-resolution active remote sensing techniques as a primary sampling tool in tropical forest biomass studies. The potential decrease in the bias and uncertainty of remotely sensed estimates of forest structure and biomass is a vital step toward successful tropical forest conservation and climate-change mitigation policy.

  14. [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.

  15. Forest biomass supply logistics for a power plant using the discrete-event simulation approach

    SciTech Connect

    Mobini, Mahdi; Sowlati, T.; Sokhansanj, Shahabaddine

    2011-04-01

    This study investigates the logistics of supplying forest biomass to a potential power plant. Due to the complexities in such a supply logistics system, a simulation model based on the framework of Integrated Biomass Supply Analysis and Logistics (IBSAL) is developed in this study to evaluate the cost of delivered forest biomass, the equilibrium moisture content, and carbon emissions from the logistics operations. The model is applied to a proposed case of 300 MW power plant in Quesnel, BC, Canada. The results show that the biomass demand of the power plant would not be met every year. The weighted average cost of delivered biomass to the gate of the power plant is about C$ 90 per dry tonne. Estimates of equilibrium moisture content of delivered biomass and CO2 emissions resulted from the processes are also provided.

  16. An Optimization-Based System Model of Disturbance-Generated Forest Biomass Utilization

    ERIC Educational Resources Information Center

    Curry, Guy L.; Coulson, Robert N.; Gan, Jianbang; Tchakerian, Maria D.; Smith, C. Tattersall

    2008-01-01

    Disturbance-generated biomass results from endogenous and exogenous natural and cultural disturbances that affect the health and productivity of forest ecosystems. These disturbances can create large quantities of plant biomass on predictable cycles. A systems analysis model has been developed to quantify aspects of system capacities (harvest,…

  17. Spatial and topographic trends in forest expansion and biomass change, from regional to local scales.

    PubMed

    Buma, Brian; Barrett, Tara M

    2015-09-01

    Natural forest growth and expansion are important carbon sequestration processes globally. Climate change is likely to increase forest growth in some regions via CO2 fertilization, increased temperatures, and altered precipitation; however, altered disturbance regimes and climate stress (e.g. drought) will act to reduce carbon stocks in forests as well. Observations of asynchrony in forest change is useful in determining current trends in forest carbon stocks, both in terms of forest density (e.g. Mg ha(-1) ) and spatially (extent and location). Monitoring change in natural (unmanaged) areas is particularly useful, as while afforestation and recovery from historic land use are currently large carbon sinks, the long-term viability of those sinks depends on climate change and disturbance dynamics at their particular location. We utilize a large, unmanaged biome (>135 000 km(2) ) which spans a broad latitudinal gradient to explore how variation in location affects forest density and spatial patterning: the forests of the North American temperate rainforests in Alaska, which store >2.8 Pg C in biomass and soil, equivalent to >8% of the C in contiguous US forests. We demonstrate that the regional biome is shifting; gains exceed losses and are located in different spatio-topographic contexts. Forest gains are concentrated on northerly aspects, lower elevations, and higher latitudes, especially in sheltered areas, whereas loss is skewed toward southerly aspects and lower latitudes. Repeat plot-scale biomass data (n = 759) indicate that within-forest biomass gains outpace losses (live trees >12.7 cm diameter, 986 Gg yr(-1) ) on gentler slopes and in higher latitudes. This work demonstrates that while temperate rainforest dynamics occur at fine spatial scales (<1000 m(2) ), the net result of thousands of individual events is regionally patterned change. Correlations between the disturbance/establishment imbalance and biomass accumulation suggest the potential for relatively

  18. Mapping aboveground woody biomass using forest inventory, remote sensing and geostatistical techniques.

    PubMed

    Yadav, Bechu K V; Nandy, S

    2015-05-01

    Mapping forest biomass is fundamental for estimating CO₂ emissions, and planning and monitoring of forests and ecosystem productivity. The present study attempted to map aboveground woody biomass (AGWB) integrating forest inventory, remote sensing and geostatistical techniques, viz., direct radiometric relationships (DRR), k-nearest neighbours (k-NN) and cokriging (CoK) and to evaluate their accuracy. A part of the Timli Forest Range of Kalsi Soil and Water Conservation Division, Uttarakhand, India was selected for the present study. Stratified random sampling was used to collect biophysical data from 36 sample plots of 0.1 ha (31.62 m × 31.62 m) size. Species-specific volumetric equations were used for calculating volume and multiplied by specific gravity to get biomass. Three forest-type density classes, viz. 10-40, 40-70 and >70% of Shorea robusta forest and four non-forest classes were delineated using on-screen visual interpretation of IRS P6 LISS-III data of December 2012. The volume in different strata of forest-type density ranged from 189.84 to 484.36 m(3) ha(-1). The total growing stock of the forest was found to be 2,024,652.88 m(3). The AGWB ranged from 143 to 421 Mgha(-1). Spectral bands and vegetation indices were used as independent variables and biomass as dependent variable for DRR, k-NN and CoK. After validation and comparison, k-NN method of Mahalanobis distance (root mean square error (RMSE) = 42.25 Mgha(-1)) was found to be the best method followed by fuzzy distance and Euclidean distance with RMSE of 44.23 and 45.13 Mgha(-1) respectively. DRR was found to be the least accurate method with RMSE of 67.17 Mgha(-1). The study highlighted the potential of integrating of forest inventory, remote sensing and geostatistical techniques for forest biomass mapping.

  19. Plant biomass in the Tanana River Basin, Alaska. Forest Service research paper

    SciTech Connect

    Mead, B.R.

    1995-01-01

    Vegetation biomass tables are presented for the Tanana River Basin. Average biomass for each species of tree, shrub, grass, forb, lichen, and moss in the 13 forest and 30 nonforest vegetation types is shown. These data combined with area estimates for each vegetation type provide a tool for estimating habitat carrying capacity for many wildlife species. Tree biomass is reported for the entire aboveground tree, thereby allowing estimates of total fiber content.

  20. Changes in Forest Production, Biomass and Carbon: Results From the 2015 UN FAO Global Forest Resource Assessment

    NASA Astrophysics Data System (ADS)

    Navar, J.

    2015-12-01

    Forests are important sources of livelihoods to millions of people and contribute to national economic development of many countries. In addition, they are vital sources and sinks of carbon and contribute to the rate of climate change. The UN Food and Agriculture Organization has been collecting and presenting data on global forest resources and forest cover since 1948. This paper builds on data from FAO's 2015 Global Forest Resource Assessment (FRA) and presents information on growing stock, biomass, carbon stock, wood removals, and changes of forest area primarily designated for production and multiple use of the world's forests. Between 1990 and 2015, the total growing stock volume has increased in East Asia, Caribbean, Western and Central Asia, North America, Europe (including the Russian Federation), and Oceania with the highest relative increase in East Asia and the Caribbean. In all other subregions the total growing stock volume decreased. North and Central America, Europe and Asia report forest C stock increases while South America and Africa report strong decreases and Oceania reports stable forest C stocks. The annual rate of decrease of forest C stock weakened between 1990 and 2015. The total volume of annual wood removals including wood fuel removals increased between 1990 and 2011, but shows a remarkable decline during the 2008-2009 economic crisis. Forest areas designated for production purposes differ considerably between subregions. The percentage of production area out of total forest area ranges between 16 percent in South America and 53 percent in Europe. Globally about one quarter of the forest area is designated to multiple use forestry. The balance between biomass growth and removals shows considerable sub-regional differences and related implications for the sustainable use of forests.

  1. Estimating forest biomass using scale linkage from tree to Landsat TM reflectance data

    NASA Astrophysics Data System (ADS)

    Ung, Chhun-Huor; Lambert, Marie-Claude; Raulier, Frédéric

    2005-10-01

    Estimates of forest biomass are needed to account for carbon at the tree, stand and regional scales. Sample plots of national forest inventories provide the basic database for these estimates. At the tree scale, a common estimation method is the use of an allometric equation that relates a tree's predicted compartment biomass yi (i = foliage, branches, stem wood or stem bark) with easily obtained non-destructive measurements, i.e., diameter at breast height (D): yi=bi1Dbi2 or with both D and tree height (H): yi=bi1Dbi2Hbi3, bik being the parameters estimated. A common paradigm observed in biomass literature considers that parameter values vary between stands and regions. At the regional scale, however, when comparing national biomass equations to regional biomass equations, our results showed no significant differences between both types of equation. These results contribute to strengthening the allometric theory as an organizing principle for quantifying the relationship between tree size and biomass across spatial scales. In tandem with the allometry theory, we used a soil-canopy model based on Li-Strahler's approach for up-scaling biomass from the tree to stand scale in a mixed hardwood-coniferous forest. Our results indicated that the shadow fraction of Landsat TM reflectance was correlated with stand biomass. However, this model is indebted with heteroscedasticity, meaning that its error increases appreciably when stand biomass density is high.

  2. Carbon dynamics of intensively managed forest along a full rotation

    NASA Astrophysics Data System (ADS)

    Moreaux, V.; Bosc, A.; Bonnefond, J.; Burlett, R.; Lamaud, E.; Sartore, M.; Trichet, P.; Chipeaux, C.; Lambrot, C.; Kowalski, A. S.; Loustau, D.

    2012-12-01

    Temperate and tropical forests are increasingly exploited for wood and biomass extraction and only one third of forest area was considered as primary in the recent FRA in 2010. Management practices affect the soil-forest-atmosphere continuum through various effects on soil and surface properties. They result ultimately in either positive or negative changes in the biomass and soil carbon pools but, if any, few datasets or modeling tools are available for quantifying their impacts on the net carbon balance of forest stands. To analyse these effects, the net half-hourly fluxes of CO2, water vapour and heat exchanges were monitored for 23 years in two closed stands of maritime pines in southwestern France. Carbon content of the aboveground biomass was measured annually and soil pools 10-early in the younger stand and 5-yearly in the mature stand. For analysing the data collected and disentangling the climate and management effects, we used the three components process-based model GRAECO+ (Loustau et al. this session) linking a 3D radiative transfer and photosynthesis model, MAESTRA, a soil carbon model adapted from ROTH-C and a plant growth model. Eddy flux data were processed, gapfilled and partitioned using the methodological recommendations (Aubinet et al. 2000, Adv. Eco. Res:30, 114-173, Falge et al. 2001, Agr. For. Meteo. : 107, 43-69, Reichstein et al. 2005, Glob. Change Biol., 11:1424-1439). Analysis of the sequence showed that, whether by an increased sensitivity to soil drought compared to the pines or by a rapid re-colonization of the inter-row after understorey removal and plowing, the weeded vegetation contributed to create specific intra-annual dynamics of the fluxes and therefore, controls the dynamics of carbon balance of the stand. After three growing seasons, the stand was already a carbon sink, but the impact of thinning and weeded vegetation removal at the age of 5-year brought the balance to almost neutral. We interpret this change as the combined

  3. Regional mapping of forest canopy water content and biomass using AIRSAR images over BOREAS study area

    NASA Technical Reports Server (NTRS)

    Saatchi, Sasan; Rignot, Eric; Vanzyl, Jakob

    1995-01-01

    In recent years, monitoring vegetation biomass over various climate zones has become the primary focus of several studies interested in assessing the role of the ecosystem responses to climate change and human activities. Airborne and spaceborne Synthetic Aperture Radar (SAR) systems provide a useful tool to directly estimate biomass due to its sensitivity to structural and moisture characteristics of vegetation canopies. Even though the sensitivity of SAR data to total aboveground biomass has been successfully demonstrated in many controlled experiments over boreal forests and forest plantations, so far, no biomass estimation algorithm has been developed. This is mainly due to the fact that the SAR data, even at lowest frequency (P-band) saturates at biomass levels of about 200 tons/ha, and the structure and moisture information in the SAR signal forces the estimation algorithm to be forest type dependent. In this paper, we discuss the development of a hybrid forest biomass algorithm which uses a SAR derived land cover map in conjunction with a forest backscatter model and an inversion algorithm to estimate forest canopy water content. It is shown that unlike the direct biomass estimation from SAR data, the estimation of water content does not depend on the seasonal and/or environmental conditions. The total aboveground biomass can then be derived from canopy water content for each type of forest by incorporating other ecological information. Preliminary results from this technique over several boreal forest stands indicate that (1) the forest biomass can be estimated with reasonable accuracy, and (2) the saturation level of the SAR signal can be enhanced by separating the crown and trunk biomass in the inversion algorithm. We have used the JPL AIRSAR data over BOREAS southern study area to test the algorithm and to generate regional scale water content and biomass maps. The results are compared with ground data and the sources of errors are discussed. Several SAR

  4. Aboveground biomass variability across intact and degraded forests in the Brazilian Amazon

    NASA Astrophysics Data System (ADS)

    Longo, Marcos; Keller, Michael; dos-Santos, Maiza N.; Leitold, Veronika; Pinagé, Ekena R.; Baccini, Alessandro; Saatchi, Sassan; Nogueira, Euler M.; Batistella, Mateus; Morton, Douglas C.

    2016-11-01

    Deforestation rates have declined in the Brazilian Amazon since 2005, yet degradation from logging, fire, and fragmentation has continued in frontier forests. In this study we quantified the aboveground carbon density (ACD) in intact and degraded forests using the largest data set of integrated forest inventory plots (n = 359) and airborne lidar data (18,000 ha) assembled to date for the Brazilian Amazon. We developed statistical models relating inventory ACD estimates to lidar metrics that explained 70% of the variance across forest types. Airborne lidar-ACD estimates for intact forests ranged between 5.0 ± 2.5 and 31.9 ± 10.8 kg C m-2. Degradation carbon losses were large and persistent. Sites that burned multiple times within a decade lost up to 15.0 ± 0.7 kg C m-2 (94%) of ACD. Forests that burned nearly 15 years ago had between 4.1 ± 0.5 and 6.8 ± 0.3 kg C m-2 (22-40%) less ACD than intact forests. Even for low-impact logging disturbances, ACD was between 0.7 ± 0.3 and 4.4 ± 0.4 kg C m-2 (4-21%) lower than unlogged forests. Comparing biomass estimates from airborne lidar to existing biomass maps, we found that regional and pantropical products consistently overestimated ACD in degraded forests, underestimated ACD in intact forests, and showed little sensitivity to fires and logging. Fine-scale heterogeneity in ACD across intact and degraded forests highlights the benefits of airborne lidar for carbon mapping. Differences between airborne lidar and regional biomass maps underscore the need to improve and update biomass estimates for dynamic land use frontiers, to better characterize deforestation and degradation carbon emissions for regional carbon budgets and Reduce Emissions from Deforestation and forest Degradation (REDD+).

  5. Aboveground Biomass and Dynamics of Forest Attributes using LiDAR Data and Vegetation Model

    NASA Astrophysics Data System (ADS)

    V V L, P. A.

    2015-12-01

    In recent years, biomass estimation for tropical forests has received much attention because of the fact that regional biomass is considered to be a critical input to climate change. Biomass almost determines the potential carbon emission that could be released to the atmosphere due to deforestation or conservation to non-forest land use. Thus, accurate biomass estimation is necessary for better understating of deforestation impacts on global warming and environmental degradation. In this context, forest stand height inclusion in biomass estimation plays a major role in reducing the uncertainty in the estimation of biomass. The improvement in the accuracy in biomass shall also help in meeting the MRV objectives of REDD+. Along with the precise estimate of biomass, it is also important to emphasize the role of vegetation models that will most likely become an important tool for assessing the effects of climate change on potential vegetation dynamics and terrestrial carbon storage and for managing terrestrial ecosystem sustainability. Remote sensing is an efficient way to estimate forest parameters in large area, especially at regional scale where field data is limited. LIDAR (Light Detection And Ranging) provides accurate information on the vertical structure of forests. We estimated average tree canopy heights and AGB from GLAS waveform parameters by using a multi-regression linear model in forested area of Madhya Pradesh (area-3,08,245 km2), India. The derived heights from ICESat-GLAS were correlated with field measured tree canopy heights for 60 plots. Results have shown a significant correlation of R2= 74% for top canopy heights and R2= 57% for stand biomass. The total biomass estimation 320.17 Mt and canopy heights are generated by using random forest algorithm. These canopy heights and biomass maps were used in vegetation models to predict the changes biophysical/physiological characteristics of forest according to the changing climate. In our study we have

  6. Changes in forest biomass carbon stock in Northern Turkey between 1973 and 2006.

    PubMed

    Misir, Mehmet

    2013-10-01

    New forest management and planning approaches are designed to optimize forest structure. Optimal forest structure was determined using newly established growth models while considering primary timber production objectives as well as non-timber objectives for inaccessible areas and social and political pressures on land management. With currently planned management the forests of the Ormanüstü Planning Unit (OPU) in the Black Sea region of northern Turkey are likely to become an important C sink. To quantify this potential C sink and understand its implication to the regional carbon budget and future forest management, we estimated the changes in the OPU between 1973 and 2006. Based on four periods of data for the OPU forests obtained from the Forest Management and Planning Office of Turkey, we used allometric biomass and C regression equations along with biomass expansion factors to estimate the forest biomass carbon pool for each of four inventory years 1973, 1984, 1997, and 2006. Since 1973, OPU forests have accumulated 110.2 × 10(3) tons of C as a result of forest expansion and the growth of extant forests, increasing by 50.8 % from 217 × 10(3) tons in 1973 to 327.2 × 10(3) tons C in 2006. Hardwood and softwood forests accounted for 44 and 56 % of carbon accumulation during this period, respectively. From 1973 through 2006, forest C accumulated at a rate of 3.3 × 10(3) tons C year(-1). Carbon density of the OPU forests in the Black Sea region increased by 48.2 % from 5,679 to 8,419 tons/ha.

  7. Mapping tropical forest biomass with radar and spaceborne LiDAR: overcoming problems of high biomass and persistent cloud

    NASA Astrophysics Data System (ADS)

    Mitchard, E. T. A.; Saatchi, S. S.; White, L. J. T.; Abernethy, K. A.; Jeffery, K. J.; Lewis, S. L.; Collins, M.; Lefsky, M. A.; Leal, M. E.; Woodhouse, I. H.; Meir, P.

    2011-08-01

    Spatially-explicit maps of aboveground biomass are essential for calculating the losses and gains in forest carbon at a regional to national level. The production of such maps across wide areas will become increasingly necessary as international efforts to protect primary forests, such as the REDD+ (Reducing Emissions from Deforestation and forest Degradation) mechanism, come into effect, alongside their use for management and research more generally. However, mapping biomass over high-biomass tropical forest is challenging as (1) direct regressions with optical and radar data saturate, (2) much of the tropics is persistently cloud-covered, reducing the availability of optical data, (3) many regions include steep topography, making the use of radar data complex, (4) while LiDAR data does not suffer from saturation, expensive aircraft-derived data are necessary for complete coverage. We present a solution to the problems, using a combination of terrain-corrected L-band radar data (ALOS PALSAR), spaceborne LiDAR data (ICESat GLAS) and ground-based data. We map Gabon's Lopé National Park (5000 km2) because it includes a range of vegetation types from savanna to closed-canopy tropical forest, is topographically complex, has no recent cloud-free high-resolution optical data, and the dense forest is above the saturation point for radar. Our 100 m resolution biomass map is derived from fusing spaceborne LiDAR (7142 ICESat GLAS footprints), 96 ground-based plots (average size 0.8 ha) and an unsupervised classification of terrain-corrected ALOS PALSAR radar data, from which we derive the aboveground biomass stocks of the park to be 78 Tg C (173 Mg C ha-1). This value is consistent with our field data average of 181 Mg C ha-1, from the field plots measured in 2009 covering a total of 78 ha, and which are independent as they were not used for the GLAS-biomass estimation. We estimate an uncertainty of ± 25 % on our carbon stock value for the park. This error term includes

  8. Exploring multi-scale forest above ground biomass estimation with optical remote sensing imageries

    NASA Astrophysics Data System (ADS)

    Koju, U.; Zhang, J.; Gilani, H.

    2017-02-01

    Forest shares 80% of total exchange of carbon between the atmosphere and the terrestrial ecosystem. Due to this monitoring of forest above ground biomass (as carbon can be calculated as 0.47 part of total biomass) has become very important. Forest above ground biomass as being the major portion of total forest biomass should be given a very careful consideration in its estimation. It is hoped to be useful in addressing the ongoing problems of deforestation and degradation and to gain carbon mitigation benefits through mechanisms like Reducing Emissions from Deforestation and Forest Degradation (REDD+). Many methods of above ground biomass estimation are in used ranging from use of optical remote sensing imageries of very high to very low resolution to SAR data and LIDAR. This paper describes a multi-scale approach for assessing forest above ground biomass, and ultimately carbon stocks, using very high imageries, open source medium resolution and medium resolution satellite datasets with a very limited number of field plots. We found this method is one of the most promising method for forest above ground biomass estimation with higher accuracy and low cost budget. Pilot study was conducted in Chitwan district of Nepal on the estimation of biomass using this technique. The GeoEye-1 (0.5m), Landsat (30m) and Google Earth (GE) images were used remote sensing imageries. Object-based image analysis (OBIA) classification technique was done on Geo-eye imagery for the tree crown delineation at the watershed level. After then, crown projection area (CPA) vs. biomass model was developed and validated at the watershed level. Open source GE imageries were used to calculate the CPA and biomass from virtual plots at district level. Using data mining technique, different parameters from Landsat imageries along with the virtual sample biomass were used for upscaling biomass estimation at district level. We found, this approach can considerably reduce field data requirements for

  9. Can intensive management increase carbon storage in forests

    SciTech Connect

    Schroeder, P.

    1991-01-01

    A possible response to increasing atmospheric CO2 concentration is to attempt to increase the amount of carbon stored in terrestrial vegetation. One approach to increasing the size of the terrestrial carbon sink is to increase the growth of forests by utilizing intensive forest management practices. The paper uses data from the literature and from forest growth and yield models to analyze the impact of three management practices on carbon storage: thinning, fertilization, and control of competing vegetation. Using Douglas-fir (Pseudotsuga menziesii) and loblolly pine (Pinus taeda) as example species, results showed that thinning generally does not increase carbon storage, and may actually cause a decrease. The exception is thinning of very dense young stands.

  10. Lessons to be learned from the past: Forest biomass utilization and its belowground consequences

    NASA Astrophysics Data System (ADS)

    Bruckman, V. J.; Glatzel, G.

    2012-04-01

    Biomass was the major source of energy until the utilization of fossil energy. Its availability is strongly linked to the rise, prosperity and fall of former civilizations. Biomass from forests became scarce in many countries as the industry developed, leading to increasing transport distances from biomass sources and vast deforested patches of land along streams. There is good evidence from the past that unsustainable biomass extraction and consequent soil degradation had significant impact on soil properties in specific cases. In Central Europe, large quantities of forest biomass were not only used as timber, fuel and raw materials for trade but were also used in agriculture. Litter raking and pollarding were common practices until the mid of the last century. More plant nutrients were extracted from forest ecosystems to sustain the human population by setting up forest pastures and harvesting of edible parts of plants as fodder utilization. Starting from the Bronze Age, mining and proto-industrialization had a significant impact on forest ecosystems mainly because of the rising demand on fuelwood, charcoal and woodash. Such historical practices led to significant base-cation loss in many forest ecosystems and subsequently to soil acidification and reduced growth. Consequences of such practices should be kept in mind when evaluating the impact of harvesting residues management (utilization of slash) which is currently discussed as a measure to lessen dependency on fossil fuels and reduce greenhouse gas emissions.

  11. Does species richness affect fine root biomass and production in young forest plantations?

    PubMed

    Domisch, Timo; Finér, Leena; Dawud, Seid Muhie; Vesterdal, Lars; Raulund-Rasmussen, Karsten

    2015-02-01

    Tree species diversity has been reported to increase forest ecosystem above-ground biomass and productivity, but little is known about below-ground biomass and production in diverse mixed forests compared to single-species forests. For testing whether species richness increases below-ground biomass and production and thus complementarity between forest tree species in young stands, we determined fine root biomass and production of trees and ground vegetation in two experimental plantations representing gradients in tree species richness. Additionally, we measured tree fine root length and determined species composition from fine root biomass samples with the near-infrared reflectance spectroscopy method. We did not observe higher biomass or production in mixed stands compared to monocultures. Neither did we observe any differences in tree root length or fine root turnover. One reason for this could be that these stands were still young, and canopy closure had not always taken place, i.e. a situation where above- or below-ground competition did not yet exist. Another reason could be that the rooting traits of the tree species did not differ sufficiently to support niche differentiation. Our results suggested that functional group identity (i.e. conifers vs. broadleaved species) can be more important for below-ground biomass and production than the species richness itself, as conifers seemed to be more competitive in colonising the soil volume, compared to broadleaved species.

  12. Economic approach to assess the forest carbon implications of biomass energy.

    PubMed

    Daigneault, Adam; Sohngen, Brent; Sedjo, Roger

    2012-06-05

    There is widespread concern that biomass energy policy that promotes forests as a supply source will cause net carbon emissions. Most of the analyses that have been done to date, however, are biological, ignoring the effects of market adaptations through substitution, net imports, and timber investments. This paper uses a dynamic model of forest and land use management to estimate the impact of United States energy policies that emphasize the utilization of forest biomass on global timber production and carbon stocks over the next 50 years. We show that when market factors are included in the analysis, expanded demand for biomass energy increases timber prices and harvests, but reduces net global carbon emissions because higher wood prices lead to new investments in forest stocks. Estimates are sensitive to assumptions about whether harvest residues and new forestland can be used for biomass energy and the demand for biomass. Restricting biomass energy to being sourced only from roundwood on existing forestland can transform the policy from a net sink to a net source of emissions. These results illustrate the importance of capturing market adjustments and a large geographic scope when measuring the carbon implications of biomass energy policies.

  13. Temperature drives global patterns in forest biomass distribution in leaves, stems, and roots

    USGS Publications Warehouse

    Reich, Peter B.; Lou, Yunjian; Bradford, John B.; Poorter, Hendrik; Perry, Charles H.; Oleksyn, Jacek

    2014-01-01

    Whether the fraction of total forest biomass distributed in roots, stems, or leaves varies systematically across geographic gradients remains unknown despite its importance for understanding forest ecology and modeling global carbon cycles. It has been hypothesized that plants should maintain proportionally more biomass in the organ that acquires the most limiting resource. Accordingly, we hypothesize greater biomass distribution in roots and less in stems and foliage in increasingly arid climates and in colder environments at high latitudes. Such a strategy would increase uptake of soil water in dry conditions and of soil nutrients in cold soils, where they are at low supply and are less mobile. We use a large global biomass dataset (>6,200 forests from 61 countries, across a 40 °C gradient in mean annual temperature) to address these questions. Climate metrics involving temperature were better predictors of biomass partitioning than those involving moisture availability, because, surprisingly, fractional distribution of biomass to roots or foliage was unrelated to aridity. In contrast, in increasingly cold climates, the proportion of total forest biomass in roots was greater and in foliage was smaller for both angiosperm and gymnosperm forests. These findings support hypotheses about adaptive strategies of forest trees to temperature and provide biogeographically explicit relationships to improve ecosystem and earth system models. They also will allow, for the first time to our knowledge, representations of root carbon pools that consider biogeographic differences, which are useful for quantifying whole-ecosystem carbon stocks and cycles and for assessing the impact of climate change on forest carbon dynamics.

  14. Temperature drives global patterns in forest biomass distribution in leaves, stems, and roots

    PubMed Central

    Reich, Peter B.; Luo, Yunjian; Bradford, John B.; Poorter, Hendrik; Perry, Charles H.; Oleksyn, Jacek

    2014-01-01

    Whether the fraction of total forest biomass distributed in roots, stems, or leaves varies systematically across geographic gradients remains unknown despite its importance for understanding forest ecology and modeling global carbon cycles. It has been hypothesized that plants should maintain proportionally more biomass in the organ that acquires the most limiting resource. Accordingly, we hypothesize greater biomass distribution in roots and less in stems and foliage in increasingly arid climates and in colder environments at high latitudes. Such a strategy would increase uptake of soil water in dry conditions and of soil nutrients in cold soils, where they are at low supply and are less mobile. We use a large global biomass dataset (>6,200 forests from 61 countries, across a 40 °C gradient in mean annual temperature) to address these questions. Climate metrics involving temperature were better predictors of biomass partitioning than those involving moisture availability, because, surprisingly, fractional distribution of biomass to roots or foliage was unrelated to aridity. In contrast, in increasingly cold climates, the proportion of total forest biomass in roots was greater and in foliage was smaller for both angiosperm and gymnosperm forests. These findings support hypotheses about adaptive strategies of forest trees to temperature and provide biogeographically explicit relationships to improve ecosystem and earth system models. They also will allow, for the first time to our knowledge, representations of root carbon pools that consider biogeographic differences, which are useful for quantifying whole-ecosystem carbon stocks and cycles and for assessing the impact of climate change on forest carbon dynamics. PMID:25225412

  15. Temperature drives global patterns in forest biomass distribution in leaves, stems, and roots.

    PubMed

    Reich, Peter B; Luo, Yunjian; Bradford, John B; Poorter, Hendrik; Perry, Charles H; Oleksyn, Jacek

    2014-09-23

    Whether the fraction of total forest biomass distributed in roots, stems, or leaves varies systematically across geographic gradients remains unknown despite its importance for understanding forest ecology and modeling global carbon cycles. It has been hypothesized that plants should maintain proportionally more biomass in the organ that acquires the most limiting resource. Accordingly, we hypothesize greater biomass distribution in roots and less in stems and foliage in increasingly arid climates and in colder environments at high latitudes. Such a strategy would increase uptake of soil water in dry conditions and of soil nutrients in cold soils, where they are at low supply and are less mobile. We use a large global biomass dataset (>6,200 forests from 61 countries, across a 40 °C gradient in mean annual temperature) to address these questions. Climate metrics involving temperature were better predictors of biomass partitioning than those involving moisture availability, because, surprisingly, fractional distribution of biomass to roots or foliage was unrelated to aridity. In contrast, in increasingly cold climates, the proportion of total forest biomass in roots was greater and in foliage was smaller for both angiosperm and gymnosperm forests. These findings support hypotheses about adaptive strategies of forest trees to temperature and provide biogeographically explicit relationships to improve ecosystem and earth system models. They also will allow, for the first time to our knowledge, representations of root carbon pools that consider biogeographic differences, which are useful for quantifying whole-ecosystem carbon stocks and cycles and for assessing the impact of climate change on forest carbon dynamics.

  16. Biomass Burning Related Ozone Damage on Vegetation Over the Amazon Forest: a Model Sensitivity Study

    NASA Astrophysics Data System (ADS)

    Sitch, S.; Folberth, G.; Pacifico, F.; Haywood, J. M.; Malavelle, F.; Rizzo, L. V.; Artaxo, P.

    2015-12-01

    The HadGEM2 earth system climate model was used to assess the impact of biomass burning on surface ozone concentrations over the Amazon forest and its impact on vegetation, under present-day climate conditions. Here we consider biomass burning emissions from wildfires, deforestation fires, agricultural forest burning, and residential and commercial combustion. Simulated surface ozone concentration is evaluated against observations taken at two sites in the Brazilian Amazon forest for years 2010 to 2012. The model is able to reproduce the observed diurnal cycle of surface ozone mixing ratio at the two sites, but overestimates the magnitude of the monthly averaged hourly measurements by 5-15 ppb for each available month at one of the sites. We vary biomass burning emissions over South America by ± 20, 40, 60, 80 and 100% to quantify the modelled impact of biomass burning on surface ozone concentrations and ozone damage on vegetation productivity over the Amazon forest. We used the ozone damage scheme in the "high" sensitivity mode to give an upper limit for this effect. Decreasing South American biomass burning emissions by 100% (i.e. to zero) reduces surface ozone concentrations (by about 15 ppb during the biomass burning season) and suggests a 15% increase in monthly mean net primary productivity averaged over the Amazon forest, with local increases up to 60 %. The simulated impact of ozone damage from present-day biomass burning on vegetation productivity is about 230 TgC yr-1. Taking into account that uncertainty in these estimates is substantial, this ozone damage impact over the Amazon forest is of the same order of magnitude as the release of carbon dioxide due to fire in South America; in effect it potentially doubles the impact of biomass burning on the carbon cycle.

  17. Biomass burning related ozone damage on vegetation over the Amazon forest: a model sensitivity study

    NASA Astrophysics Data System (ADS)

    Pacifico, F.; Folberth, G. A.; Sitch, S.; Haywood, J. M.; Rizzo, L. V.; Malavelle, F. F.; Artaxo, P.

    2015-03-01

    The HadGEM2 earth system climate model was used to assess the impact of biomass burning on surface ozone concentrations over the Amazon forest and its impact on vegetation, under present-day climate conditions. Here we consider biomass burning emissions from wildfires, deforestation fires, agricultural forest burning, and residential and commercial combustion. Simulated surface ozone concentration is evaluated against observations taken at two sites in the Brazilian Amazon forest for years 2010 to 2012. The model is able to reproduce the observed diurnal cycle of surface ozone mixing ratio at the two sites, but overestimates the magnitude of the monthly averaged hourly measurements by 5-15 ppb for each available month at one of the sites. We vary biomass burning emissions over South America by ±20, 40, 60, 80 and 100% to quantify the modelled impact of biomass burning on surface ozone concentrations and ozone damage on vegetation productivity over the Amazon forest. We used the ozone damage scheme in the "high" sensitivity mode to give an upper limit for this effect. Decreasing South American biomass burning emissions by 100% (i.e. to zero) reduces surface ozone concentrations (by about 15 ppb during the biomass burning season) and suggests a 15% increase in monthly mean net primary productivity averaged over the Amazon forest, with local increases up to 60%. The simulated impact of ozone damage from present-day biomass burning on vegetation productivity is about 230 TgC yr-1. Taking into account that uncertainty in these estimates is substantial, this ozone damage impact over the Amazon forest is of the same order of magnitude as the release of carbon dioxide due to fire in South America; in effect it potentially doubles the impact of biomass burning on the carbon cycle.

  18. A Forest Biomass Survey by Bitterlich Method With an Electronic Relascope for Satellite Data Validation

    NASA Astrophysics Data System (ADS)

    Suzuki, R.; Ishii, R.; Takao, G.; Nakano, T.; Yasuda, T.

    2006-12-01

    For the better understanding of the carbon cycle in the global ecosystem, an investigation on the spatio- temporal variation of the carbon stock which is stored as vegetation biomass should be important. "PALSAR (Phased Array type L-band Synthetic Aperture Radar)", an onboard sensor of the polar orbiting satellite "ALOS (Advanced Land Observing Satellite)" launched in January 2006, provides the information which can be used for the above-ground biomass estimation. It is expected that ALOS/PALSAR provides us a great opportunity to analyze the biomass dynamics over extensive regions. To derive the biomass from the ALOS/PALSAR measurement, it is inevitable to acquire in situ biomass measurement by ground-based forest surveys. Moreover, it is required to obtain such ground-based information at as possible many sites, because the region targeted by satellite remote sensing is extensive and the forest structure in that region is various. Therefore, a quick forest survey will be required to measure the biomass at as possible many sites. For the quick measurement of the forest above-ground biomass, we propose a way that is a combination of Bitterlich angle count sampling method and sampled-tree measuring method. First, a tree which has wider trunk than the basal area factor (BAF) angle is identified by the relascope from a representative point in the target forest. Next, the tree height and the breast height diameter (DBH) of the sampled tree are measured. The biomass of the tree is estimate by the allometric equation with the tree height and DBH measurements. Through these processes, the biomass density of the sampled tree per the forest area defined by the BAF is estimated. By sampling and measuring all trees (usually around 20 trees), the biomass of the forest can be estimate. A brand-new electronic relascope (Criterion RD 1000, Laser Technology Inc.) and laser range finder (TruPulse 200, Laser Technology Inc.) are used for the tree height and DBH measurements to

  19. Predicting tree heights for biomass estimates in tropical forests - a test from French Guiana

    NASA Astrophysics Data System (ADS)

    Molto, Q.; Hérault, B.; Boreux, J.-J.; Daullet, M.; Rousteau, A.; Rossi, V.

    2014-06-01

    The recent development of REDD+ mechanisms requires reliable estimation of carbon stocks, especially in tropical forests that are particularly threatened by global changes. Even though tree height is a crucial variable for computing aboveground forest biomass (AGB), it is rarely measured in large-scale forest censuses because it requires extra effort. Therefore, tree height has to be predicted with height models. The height and diameter of all trees over 10 cm in diameter were measured in 33 half-hectare plots and 9 one-hectare plots throughout northern French Guiana, an area with substantial climate and environmental gradients. We compared four different model shapes and found that the Michaelis-Menten shape was most appropriate for the tree biomass prediction. Model parameter values were significantly different from one forest plot to another, and this leads to large errors in biomass estimates. Variables from the forest stand structure explained a sufficient part of plot-to-plot variations of the height model parameters to improve the quality of the AGB predictions. In the forest stands dominated by small trees, the trees were found to have rapid height growth for small diameters. In forest stands dominated by larger trees, the trees were found to have the greatest heights for large diameters. The aboveground biomass estimation uncertainty of the forest plots was reduced by the use of the forest structure-based height model. It demonstrated the feasibility and the importance of height modeling in tropical forests for carbon mapping. When the tree heights are not measured in an inventory, they can be predicted with a height-diameter model and incorporating forest structure descriptors may improve the predictions.

  20. Anthropogenic Land-use Change and the Dynamics of Amazon Forest Biomass

    NASA Technical Reports Server (NTRS)

    Laurance, William F.

    2004-01-01

    This project was focused on assessing the effects of prevailing land uses, such as habitat fragmentation, selective logging, and fire, on biomass and carbon storage in Amazonian forests, and on the dynamics of carbon sequestration in regenerating forests. Ancillary goals included developing GIs models to help predict the future condition of Amazonian forests, and assessing the effects of anthropogenic climate change and ENS0 droughts on intact and fragmented forests. Ground-based studies using networks of permanent plots were linked with remote-sensing data (including Landsat TM and AVHRR) at regional scales, and higher-resolution techniques (IKONOS imagery, videography, LIDAR, aerial photographs) at landscape and local scales. The project s specific goals were quite eclectic and included: Determining the effects of habitat fragmentation on forest dynamics, floristic composition, and the various components of above- and below-ground biomass. Assessing historical and physical factors that affect trajectories of forest regeneration and carbon sequestration on abandoned lands. Extrapolating results from local studies of biomass dynamics in fragmented and regenerating forests to landscape and regional scales in Amazonia, using remote sensing and GIS. Testing the hypothesis that intact Amazonian forests are functioning as a significant carbon sink. Examining destructive synergisms between forest fragmentation and fire. Assessing the short-term impacts of selective logging on aboveground biomass. Developing GIS models that integrate current spatial data on forest cover, deforestation, logging, mining, highway and roads, navigable rivers, vulnerability to wild fires, protected areas, and existing and planned infrastructure projects, in an effort to predict the future condition of Brazilian Amazonian forests over the next 20-25 years. Devising predictive spatial models to assess the influence of varied biophysical and anthropogenic predictors on Amazonian deforestation.

  1. Above ground biomass and tree species richness estimation with airborne lidar in tropical Ghana forests

    NASA Astrophysics Data System (ADS)

    Vaglio Laurin, Gaia; Puletti, Nicola; Chen, Qi; Corona, Piermaria; Papale, Dario; Valentini, Riccardo

    2016-10-01

    Estimates of forest aboveground biomass are fundamental for carbon monitoring and accounting; delivering information at very high spatial resolution is especially valuable for local management, conservation and selective logging purposes. In tropical areas, hosting large biomass and biodiversity resources which are often threatened by unsustainable anthropogenic pressures, frequent forest resources monitoring is needed. Lidar is a powerful tool to estimate aboveground biomass at fine resolution; however its application in tropical forests has been limited, with high variability in the accuracy of results. Lidar pulses scan the forest vertical profile, and can provide structure information which is also linked to biodiversity. In the last decade the remote sensing of biodiversity has received great attention, but few studies focused on the use of lidar for assessing tree species richness in tropical forests. This research aims at estimating aboveground biomass and tree species richness using discrete return airborne lidar in Ghana forests. We tested an advanced statistical technique, Multivariate Adaptive Regression Splines (MARS), which does not require assumptions on data distribution or on the relationships between variables, being suitable for studying ecological variables. We compared the MARS regression results with those obtained by multilinear regression and found that both algorithms were effective, but MARS provided higher accuracy either for biomass (R2 = 0.72) and species richness (R2 = 0.64). We also noted strong correlation between biodiversity and biomass field values. Even if the forest areas under analysis are limited in extent and represent peculiar ecosystems, the preliminary indications produced by our study suggest that instrument such as lidar, specifically useful for pinpointing forest structure, can also be exploited as a support for tree species richness assessment.

  2. Model Effects on GLAS-Based Regional Estimates of Forest Biomass and Carbon

    NASA Technical Reports Server (NTRS)

    Nelson, Ross F.

    2010-01-01

    Ice, Cloud, and land Elevation Satellite (ICESat) / Geosciences Laser Altimeter System (GLAS) waveform data are used to estimate biomass and carbon on a 1.27 X 10(exp 6) square km study area in the Province of Quebec, Canada, below the tree line. The same input datasets and sampling design are used in conjunction with four different predictive models to estimate total aboveground dry forest biomass and forest carbon. The four models include non-stratified and stratified versions of a multiple linear model where either biomass or (biomass)(exp 0.5) serves as the dependent variable. The use of different models in Quebec introduces differences in Provincial dry biomass estimates of up to 0.35 G, with a range of 4.94 +/- 0.28 Gt to 5.29 +/-0.36 Gt. The differences among model estimates are statistically non-significant, however, and the results demonstrate the degree to which carbon estimates vary strictly as a function of the model used to estimate regional biomass. Results also indicate that GLAS measurements become problematic with respect to height and biomass retrievals in the boreal forest when biomass values fall below 20 t/ha and when GLAS 75th percentile heights fall below 7 m.

  3. Tropical Forest Biomass Estimation from Vertical Fourier Transforms of Lidar and InSAR Profiles

    NASA Astrophysics Data System (ADS)

    Treuhaft, R. N.; Goncalves, F.; Drake, J.; Hensley, S.; Chapman, B. D.; Michel, T.; Dos Santos, J. R.; Dutra, L.; Graca, P. A.

    2010-12-01

    Structural forest biomass estimation from lidar or interferometric SAR (InSAR) has demonstrated better performance than radar-power-based approaches for the higher biomasses (>150 Mg/ha) found in tropical forests. Structural biomass estimation frequently regresses field biomass to some function of forest height. With airborne, 25-m footprint lidar data and fixed-baseline C-band InSAR data over tropical wet forests of La Selva Biological Station, Costa Rica, we compare the use of Fourier transforms of vertical profiles at a few frequencies to the intrinsically low-frequency “average height”. RMS scatters of Fourier-estimated biomass about field-measured biomass improved by 40% and 20% over estimates base on average height from lidar and fixed-baseline InSAR, respectively. Vertical wavelengths between 14 and 100 m were found to best estimate biomass. The same airborne data acquisition over La Selva was used to generate many 10’s of repeat-track L-band InSAR baselines with time delays of 1-72 hours, and vertical wavelengths of 5-100 m. We will estimate biomass from the Fourier transforms of L-band radar power profiles (InSAR complex coherence). The effects of temporal decorrelation will be modeled in the Fourier domain to try to model and reduce their impact. Using L-band polarimetric interferometry, average heights will be estimated as well and biomass regression performance compared to the Fourier transform approach. The more traditional approach of using L-band radar polarimetry will also be compared to structural biomass estimation.

  4. Increasing the biomass production of short rotation coppice forests. Progress report

    SciTech Connect

    Steinbeck, K.; Brown, C. L.

    1980-09-01

    The objective of the project is to increase biomass yields from coppice forests by admixing tree species (Alnus glutinosa, Robinia pseudoacacia and others) to plantations of Platanus occidentalis and Liquidambar styraciflua. Yield increases due to intensive cultivation, especially fertilization and irrigation, will be documented. A genetic improvement program of promising candidate species both through the identification of superior genotypes and mass cloning with tissue culture is also included. Three plantings have been established successfully to screen candidate species on various sites and to test the effects of weed control, fertilization and irrigation on short rotation forests. Two plantations in Georgia are in their 2nd and 3rd growing seasons while one in South Carolina is in its 1st growing season. A two acre plantation has been established to test development of geographic seed source material for sycamore. A nursery is in operation to develop seedling production methods for new species and to grow and maintain genetic material. Mass cloning of selected material by tissue culture techniques has produced material for testing in outplantings.

  5. Estimating Above Ground Biomass using LiDAR in the Northcoast Redwood Forests

    NASA Astrophysics Data System (ADS)

    Rao, M.; Stewart, E.

    2010-12-01

    In recent years, LiDAR (Light Intensity Detection Amplification and Ranging) is increasingly being used in estimating biophysical parameters related to forested environments. The main goal of the project is to estimate long-term biomass accumulation and carbon sequestration potential of the redwoods ecosystem. The project objectives are aimed at providing an assessment of carbon pools within the redwood ecosystem. Specifically, we intend to develop a relational model based on LiDAR-based canopy estimates and extensive ground-based measurements available for the old-growth redwood forest located within the Prairie Creek Redwoods State Park, CA. Our preliminary analysis involved developing a geospatial database, including LiDAR data collected in 2007 for the study site, and analyzing the data using USFS Fusion software. The study area comprised of a 12-acres section of coastal redwood (Sequoia sempervirens) in the Prairie Creek Redwoods State Park, located in Orick, CA. A series of analytical steps were executed using the USFS FUSION software to produce some intermediate data such as bare earth model, canopy height model, canopy coverage model, and canopy maxima treelist. Canopy maxima tree tops were compared to ground layer to determine height of tree tops. A total of over 1000 trees were estimated, and then with thinning (to eliminate errors due to low vegetation > 3 meters tall), a total of 950 trees were delineated. Ground measurements were imported as a point based shapefile and then compared to the treetop heights created from LiDAR data to the actual ground referenced data. The results were promising as most estimated treetops were within 1-3 meters of the ground measurements and generally within 3-5m of the actual tree height. Finally, we are in the process of applying some allometric equations to estimate above ground biomass using some of the LiDAR-derived canopy metrics.

  6. Monitoring firefighter exposure to air toxins at prescribed burns of forest and range biomass. Forest Service research paper

    SciTech Connect

    Reinhardt, T.E.

    1991-10-01

    A variety of potent air toxins are in the smoke produced by burning forest and range biomass. Preliminary data on firefighter exposures to carbon monoxide and formaldehyde at four prescribed burns of Western United States natural fuels are presented. Formaldehyde may be correlated to carbon monoxide emissions. The firefighters' exposures to these compounds relative to workplace standards are discussed.

  7. Simulating impacts of Woody Biomass Harvesting on North Temperate Forest Carbon and Nitrogen Cycling and Storage

    NASA Astrophysics Data System (ADS)

    Hua, D.; Desai, A. R.; Bolstad, P.; Cook, B. D.; Scheller, R.

    2012-12-01

    Woody biomass harvesting is a common feature of forest management given its importance to society for acquisition of pulp and paper, lumber, and wood-based biofuel. Harvest affects many aspects of the forest environment such as biodiversity, soil nutrient quality, physical properties of soil, water quality, wildlife habitat, and climate feedbacks. In this study, we applied a modified CENTURY model to the Willow Creek, Wisconsin Ameriflux site for simulation of the impacts of woody biomass removal on forest carbon and nitrogen storage. Woody biomass harvesting scenarios with different harvesting types, interval, tree species, and soil properties were designed and tested in the model to explore the impact of harvesting on forest productivity, soil and biomass carbon and nitrogen storage, and net carbon exchange between terrestrial ecosystem and the atmosphere. Comparisons of the impacts among harvesting scenarios indicate that woody biomass harvesting significantly alters long-term net soil carbon and nitrogen storage as well as carbon exchange between terrestrial ecosystem and the atmosphere. The simulation results also provide a framework for incorporating carbon management into sustainable forest management practices.

  8. 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

  9. 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.

  10. 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

  11. Estimation of forest biomass by integrating ALOS PALSAR And HJ1B data

    NASA Astrophysics Data System (ADS)

    Wang, X. Y.; Guo, Y. G.; He, J.

    2014-11-01

    The use of the optical and microwave remote sensing in combination with field measured data can provide an effective way to improve the estimation of forest biomass over large regions. In order to improve the accuracy of biomass estimation from remotely sensed data in mountainous terrain, the methods for obtaining above-ground biomass (AGB) from forest canopy structure estimates based on a physically-based canopy reflectance model estimation approach was introduced in this paper. A geometric-optical canopy reflectance model was run in multiple-forward mode (MFM) using HJ1B imagery to derive forest biomass at Helan Mountain nature reserve region in the northwest of China. Simultaneously, the multiple regression model was also developed to estimate the forest above-ground biomass by integrating field measurements of 30 sample plots with ALOS/PALSAR Synthetic Aperture Radar (SAR) backscatter remotely sensed data. The estimation biomass of two methods was evaluated with 20 field validation sites. MFM predictions of AGB from HJ1B imagery were compared with the results from PALSAR regression model, respectively. Error levels for two model and field measured data were also analyzed. The result shows that a good fit can be found between AGB estimated by geometric-optical canopy reflectance model and ground measured biomass with a R2 (Coefficient of Determination) and RMSE (Root Mean-Square Error) of 0.61 and 8.33 t/ha respectively. MFM provides lower error for all validation plots and its estimated accuracy is better than PALSAR regression model, whick has less accuracy estimation (R2=0.39, RMSE=14.89 t/ha). Consequently, it can conclude that geometric-optical canopy reflectance model was considerably more suitable for estimating forest biomass in mountainous terrain.

  12. [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.

  13. Changes in Amazonian forest biomass, dynamics, and composition, 1980-2002

    NASA Astrophysics Data System (ADS)

    Phillips, Oliver L.; Higuchi, Niro; Vieira, Simone; Baker, Timothy R.; Chao, Kuo-Jung; Lewis, Simon L.

    Long-term, on-the-ground monitoring of forest plots distributed across Amazonia provides a powerful means to quantify stocks and fluxes of biomass and biodiversity. Here we examine the evidence for concerted changes in the structure, dynamics, and functional composition of old-growth Amazonian forests over recent decades. Mature forests have, as a whole, gained biomass and undergone accelerated growth and dynamics, but questions remain as to the long-term persistence of these changes. Because forest growth on average exceeds mortality, intact Amazonian forests have been functioning as a carbon sink. We estimate a net biomass increase in trees ≥10 cm diameter of 0.62 ± 0.23 t C ha-1 a-1 through the late twentieth century. If representative of the wider forest landscape, this translates into a sink in South American old-growth forest of at least 0.49 ± 0.18 Pg C a-1. If other biomass and necromass components also increased proportionally, the estimated South American old-growth forest sink is 0.79 ± 0.29 Pg C a-1, before allowing for possible gains in soil carbon. If tropical forests elsewhere are behaving similarly, the old-growth biomass forest sink would be 1.60 ± 0.58 Pg C a-1. This bottom-up estimate of the carbon balance of tropical forests is preliminary, pending syntheses of detailed biometric studies across the other tropical continents. There is also some evidence for recent changes in the functional composition (biodiversity) of Amazonian forest, but the evidence is less comprehensive than that for changes in structure and dynamics. The most likely driver(s) of changes are recent increases in the supply of resources such as atmospheric carbon dioxide, which would increase net primary productivity, increasing tree growth and recruitment, and, in turn, mortality. In the future the growth response of remaining undisturbed Amazonian forests is likely to saturate, and there is a risk of these ecosystems transitioning from sink to source driven by higher

  14. Effects of biomass utilization on the carbon balance of Finnish forests

    NASA Astrophysics Data System (ADS)

    Sievänen, Risto; Salminen, Olli; Kallio, Maarit

    2015-04-01

    The boreal forests cover three fourths of the land area of Finland. About 80 per cent of the total forest area is managed for commercial forestry. The forests produce timber for wood processing and pulp and paper industries and provide also bioenergy. The harvests of timber vary depending on demand of products of forest industry; the harvest level has been on average about 70 per cent of growth in recent years. The utilization of forest biomass is therefore the most important factor affecting the carbon balance of Finnish forests. We made projections of carbon balance of Finnish forests during 2012-2050 based on scenarios of timber and bioenergy demands. To assess the changes in carbon stock of forests, we combined three models: a large-scale forestry model, the soil carbon model Yasso07 for mineral soils, and a method based on emission factors for peatland soils. We considered two harvest scenarios based on the recent projections of plausible levels (min, max) of timber demand. For the bioenergy demand, we compared cases in which the wood energy use was low or high. In the past decades, the Finnish forests have been a steadily growing and substantial carbon sink. Its size has been more than 40% of the national GHG emissions during 1990-2012. The planned use of wood from the forests to forest and energy industry does not threaten the increasing trend of the forest sink; with the lowest use of forest biomass the sink may even match the national GHG emissions until 2050. The stock change of trees is the most important component of carbon balance of forests; it accounts for approximately 80 % of the total stock change. Trees and mineral soils act as carbon sinks and the drained peatland soils as a carbon source. By comparing the scenarios of wood energy use we conclude that the amount of carbon emissions avoided by replacing fossil fuels with stemwood is outweighed by the loss in carbon sequestration.

  15. Biology and management of insect pests in North American intensively managed hardwood forest systems.

    SciTech Connect

    Coyle, David R.; Nebeker, T., E.; Hart, E., R.; Mattson, W., J.

    2005-01-01

    Annu. Rev. Entomol. 50:1-29. Abstract Increasing demand for wood and wood products is putting stress on traditional forest production areas, leading to long-term economic and environmental concerns. Intensively managed hardwood forest systems (IMHFS), grown using conventional agricultural as well as forestry methods, can help alleviate potential problems in natural forest production areas. Although IMHFS can produce more biomass per hectare per year than natural forests, the ecologically simplified, monocultural systems may greatly increase the crops susceptibility to pests. Species in the genera Populus and Salix comprise the greatest acreage in IMHFS in North America, but other species, including Liquidambar styracifua and Platanus occidentalis, are also important. We discuss life histories, realized and potential damage, and management options for the most economically infuential pests that affect these hardwood species. The substantial inherent challenges associated with pest management in the monocultural environments created by IMHFS are reviewed. Finally, we discuss ways to design IMHFS that may reduce their susceptibility to pests, increase their growth and productivity potential, and create a more sustainable environment.

  16. Evaluation of approaches to estimating aboveground biomass in southern pine forests using SIR-C data

    SciTech Connect

    Harrell, P.A.; Haney, E.M.; Christensen, N.L. Jr.; Kasischke, E.S.; Bourgeau-Chavez, L.L.

    1997-02-01

    Estimation of forest biomass on a global basis is a key issue in studies of ecology and biogeochemical cycling. Forests are a terrestrial sink of atmospheric carbon dioxide and play a central role in regulating the exchange of this important greenhouse gas between the atmosphere and the biosphere. A study was performed to evaluate various techniques for estimating aboveground, woody plant biomass in pine stands found in the southeastern United States, using C- and L- band multiple polarization radar imagery collected by the Shuttle Imaging Radar-C (SIR-C) system. The biomass levels present in the test stands ranged between 0.0 and 44.5 kg m{sup {minus}2}. Two SIR-C data sets were used one collected in April, 1994, when the soil conditions were very wet and the canopy was slightly wet from dew and a second collected in October, 1994, when the soils and canopy were dry. During the October mission, pine needles were completely flushed and the foliar biomass was twice as great in the forest stands as in April. Four methods were evaluated to estimate total biomass: one including a straight multiple linear correlation between total biomass and the various SIR-C channels, another including a ratio of the L-band HV/C-band HV channels; and two others requiring multiple steps, where linear regression equations for different stand components were used as the basis for estimating total biomass.

  17. Biomass is the main driver of changes in ecosystem process rates during tropical forest succession.

    PubMed

    Lohbeck, Madelon; Poorter, Lourens; Martínez-Ramos, Miguel; Bongers, Frans

    2015-05-01

    Over half of the world's forests are disturbed, and the rate at which ecosystem processes recover after disturbance is important for the services these forests can provide. We analyze the drivers' underlying changes in rates of key ecosystem processes (biomass productivity, litter productivity, actual litter decomposition, and potential litter decomposition) during secondary succession after shifting cultivation in wet tropical forest of Mexico. We test the importance of three alternative drivers of ecosystem processes: vegetation biomass (vegetation quantity hypothesis), community-weighted trait mean (mass ratio hypothesis), and functional diversity (niche complementarity hypothesis) using structural equation modeling. This allows us to infer the relative importance of different mechanisms underlying ecosystem process recovery. Ecosystem process rates changed during succession, and the strongest driver was aboveground biomass for each of the processes. Productivity of aboveground stem biomass and leaf litter as well as actual litter decomposition increased with initial standing vegetation biomass, whereas potential litter decomposition decreased with standing biomass. Additionally, biomass productivity was positively affected by community-weighted mean of specific leaf area, and potential decomposition was positively affected by functional divergence, and negatively by community-weighted mean of leaf dry matter content. Our empirical results show that functional diversity and community-weighted means are of secondary importance for explaining changes in ecosystem process rates during tropical forest succession. Instead, simply, the amount of vegetation in a site is the major driver of changes, perhaps because there is a steep biomass buildup during succession that overrides more subtle effects of community functional properties on ecosystem processes. We recommend future studies in the field of biodiversity and ecosystem functioning to separate the effects of

  18. Biomass and carotenoid production in photosynthetic bacteria wastewater treatment: effects of light intensity.

    PubMed

    Zhou, Qin; Zhang, Panyue; Zhang, Guangming

    2014-11-01

    This study investigated the feasibility of using photosynthetic bacteria (PSB) to produce biomass and carotenoid while treating wastewater. The effects of light intensity on the biomass, carotenoid and bacteriochlorophyll accumulation in together with pollutant removal were studied. Results showed that it was feasible to use PSB to treat wastewater as well as to produce biomass or carotenoid. 2000 lux was an optimal intensity for biomass production and COD removal, and the corresponding values were 2645 mg/L and 94.7%. 8000 lux was an optimal light intensity for carotenoid production (1.455 mg/L). Mechanism analysis displayed that the greater the bacteriochlorophyll and carotenoid were secreted, the lower the light conversion efficiency turned out to be. The highest light conversion efficiency was achieved at 500 lux; the ATP production, biomass production, and COD removal were the highest at 2000 lux, but the bacteriochlorophyll and carotenoid content were the lowest at 2000 lux.

  19. Achieving Accuracy Requirements for Forest Biomass Mapping: A Data Fusion Method for Estimating Forest Biomass and LiDAR Sampling Error with Spaceborne Data

    NASA Technical Reports Server (NTRS)

    Montesano, P. M.; Cook, B. D.; Sun, G.; Simard, M.; Zhang, Z.; Nelson, R. F.; Ranson, K. J.; Lutchke, S.; Blair, J. B.

    2012-01-01

    The synergistic use of active and passive remote sensing (i.e., data fusion) demonstrates the ability of spaceborne light detection and ranging (LiDAR), synthetic aperture radar (SAR) and multispectral imagery for achieving the accuracy requirements of a global forest biomass mapping mission. This data fusion approach also provides a means to extend 3D information from discrete spaceborne LiDAR measurements of forest structure across scales much larger than that of the LiDAR footprint. For estimating biomass, these measurements mix a number of errors including those associated with LiDAR footprint sampling over regional - global extents. A general framework for mapping above ground live forest biomass (AGB) with a data fusion approach is presented and verified using data from NASA field campaigns near Howland, ME, USA, to assess AGB and LiDAR sampling errors across a regionally representative landscape. We combined SAR and Landsat-derived optical (passive optical) image data to identify forest patches, and used image and simulated spaceborne LiDAR data to compute AGB and estimate LiDAR sampling error for forest patches and 100m, 250m, 500m, and 1km grid cells. Forest patches were delineated with Landsat-derived data and airborne SAR imagery, and simulated spaceborne LiDAR (SSL) data were derived from orbit and cloud cover simulations and airborne data from NASA's Laser Vegetation Imaging Sensor (L VIS). At both the patch and grid scales, we evaluated differences in AGB estimation and sampling error from the combined use of LiDAR with both SAR and passive optical and with either SAR or passive optical alone. This data fusion approach demonstrates that incorporating forest patches into the AGB mapping framework can provide sub-grid forest information for coarser grid-level AGB reporting, and that combining simulated spaceborne LiDAR with SAR and passive optical data are most useful for estimating AGB when measurements from LiDAR are limited because they minimized

  20. Climate change-associated trends in net biomass change are age dependent in western boreal forests of Canada.

    PubMed

    Chen, Han Y H; Luo, Yong; Reich, Peter B; Searle, Eric B; Biswas, Shekhar R

    2016-09-01

    The impacts of climate change on forest net biomass change are poorly understood but critical for predicting forest's contribution to the global carbon cycle. Recent studies show climate change-associated net biomass declines in mature forest plots. The representativeness of these plots for regional forests, however, remains uncertain because we lack an assessment of whether climate change impacts differ with forest age. Using data from plots of varying ages from 17 to 210 years, monitored from 1958 to 2011 in western Canada, we found that climate change has little effect on net biomass change in forests ≤ 40 years of age due to increased growth offsetting increased mortality, but has led to large decreases in older forests due to increased mortality accompanying little growth gain. Our analysis highlights the need to incorporate forest age profiles in examining past and projecting future forest responses to climate change.

  1. ESTIMATION OF TROPICAL FOREST STRUCTURE AND BIOMASS FROM FUSION OF RADAR AND LIDAR MEASUREMENTS (Invited)

    NASA Astrophysics Data System (ADS)

    Saatchi, S. S.; Dubayah, R.; Clark, D. B.; Chazdon, R.

    2009-12-01

    Radar and Lidar instruments are active remote sensing sensors with the potential of measuring forest vertical and horizontal structure and the aboveground biomass (AGB). In this paper, we present the analysis of radar and lidar data acquired over the La Selva Biological Station in Costa Rica. Radar polarimetry at L-band (25 cm wavelength), P-band (70 cm wavelength) and interferometry at C-band (6 cm wavelength) and VV polarization were acquired by the NASA/JPL airborne synthetic aperture radar (AIRSAR) system. Lidar images were provided by a large footprint airborne scanning Lidar known as the Laser Vegetation Imaging Sensor (LVIS). By including field measurements of structure and biomass over a variety of forest types, we examined: 1) sensitivity of radar and lidar measurements to forest structure and biomass, 2) accuracy of individual sensors for AGB estimation, and 3) synergism of radar imaging measurements with lidar imaging and sampling measurements for improving the estimation of 3-dimensional forest structure and AGB. The results showed that P-band radar combined with any interformteric measurement of forest height can capture approximately 85% of the variation of biomass in La Selva at spatial scales larger than 1 hectare. Similar analysis at L-band frequency captured only 70% of the variation. However, combination of lidar and radar measurements improved estimates of forest three-dimensional structure and biomass to above 90% for all forest types. We present a novel data fusion approach based on a Baysian estimation model with the capability of incorporating lidar samples and radar imagery. The model was used to simulate the potential of data fusion in future satellite mission scenarios as in BIOMASS (planned by ESA) at P-band and DESDynl (planned by NASA) at L-band. The estimation model was also able to quantify errors and uncertainties associated with the scale of measurements, spatial variability of forest structure, and differences in radar and lidar

  2. Forest Aboveground Biomass Estimation in the Greater Mekong, Subregion and Russian Siberia

    NASA Astrophysics Data System (ADS)

    Pang, Yong; Li, Zengyuan; Sun, Gouqing; Zhang, Zhiyu; Schmullius, Christiane; Meng, Shili; Ma, Zhenyu; Lu, Hao; Li, Shiming; Liu, Qingwang; Bai, Lina; Tian, Xin

    2016-08-01

    Forests play a vital role in sustainable development and provide a range of economic, social and environmental benefits, including essential ecosystem services such as climate change mitigation and adaptation. We summarized works in forest aboveground biomass estimation in Greater Mekong Subregion (GMS) and Russian Siberia (RuS). Both regions are rich in forest resources. These mapping and estimation works were based on multiple-source remote sensing data and some field measurements. Biomass maps were generated at 500 m and 30 m pixel size for RuS and GMS respectively. With the available of the 2015 PALSAR-2 mosaic at 25 m spacing, Sentinel-2 data at 20 m, we will work on the biomass mapping and dynamic study at higher spatial resolution.

  3. Biomass mapping using biophysical forest type characterisation of SAR polarimetric images

    NASA Astrophysics Data System (ADS)

    Quiñones, Marcela J.; Hoekman, Dirk H.

    2002-01-01

    Studies on the relationship between biomass and radar backscatter have relied on field data to construct empirical relationships with radar backscatter that can be used for biomass estimations and mapping. In general, inversion of radar data for biomass estimations is limited by the variations on backscatter produced by structural parameters and soil moisture and limited to a certain maximum biomass level dependent on the structural class. In this work we created biomass maps of two study sites at the Colombian Amazon (Guaviare and Araracuara) by using results from polarimetric classification algorithm that combines power, phase and correlation of C, L and P band of AirSAR data. Two different approaches were used. For the Guaviare site, (dry and flat) the biomass classes selected are related to Land Cover types and an empirical relationship between biomass and the average backscatter (LHV+PRR)/2) is used to create the biomass map. High consistency with the cover map is found. For the Araracuara site (hilly and flooded) a biomass map is created by reclassifying a biophysical forest structural map with biomass values obtained from field available data. Field data is used to validate maps and to study the behavior of radar polarimetric signatures according to different forest structures. A new approach of analysis is based on the description of the polarimetric coherence according to a physical explanation of the wave-object interactions. The same type of analysis is used to study systematically the influence of different forest structural parameters and soil moisture conditions on the polarimetric signatures. Simulated radar data from the UTARTCAN backscatter model is used.

  4. Comparison of the gaseous and particulate matter emissions from the combustion of agricultural and forest biomasses.

    PubMed

    Brassard, Patrick; Palacios, Joahnn H; Godbout, Stéphane; Bussières, Denis; Lagacé, Robert; Larouche, Jean-Pierre; Pelletier, Frédéric

    2014-03-01

    The aim of this study was to compare gaseous and particulate matter (PM) emissions from the combustion of agricultural (switchgrass, fast-growing willow and the dried solid fraction of pig manure) and forest (wood mixture of Black Spruce and Jack Pine) biomasses in a small-scale unit (17.58kW). Concentrations of CO2, CO, CH4, NO2, NH3, N2O, SO2, HCl, and H2O were measured by Fourier transform infrared spectroscopy and converted into emission rates. Opacity was also evaluated and particulates were sampled. Results showed significantly higher emissions of SO2, NO2 and PM with the combustion of agricultural biomass compared to the forest biomass. However, further studies should be carried out so regulations can be adapted in order to permit the combustion of agricultural biomass in small-scale combustion units.

  5. A meta-analysis of soil microbial biomass responses to forest disturbances

    PubMed Central

    Holden, Sandra R.; Treseder, Kathleen K.

    2013-01-01

    Climate warming is likely to increase the frequency and severity of forest disturbances, with uncertain consequences for soil microbial communities and their contribution to ecosystem C dynamics. To address this uncertainty, we conducted a meta-analysis of 139 published soil microbial responses to forest disturbances. These disturbances included abiotic (fire, harvesting, storm) and biotic (insect, pathogen) disturbances. We hypothesized that soil microbial biomass would decline following forest disturbances, but that abiotic disturbances would elicit greater reductions in microbial biomass than biotic disturbances. In support of this hypothesis, across all published studies, disturbances reduced soil microbial biomass by an average of 29.4%. However, microbial responses differed between abiotic and biotic disturbances. Microbial responses were significantly negative following fires, harvest, and storms (48.7, 19.1, and 41.7% reductions in microbial biomass, respectively). In contrast, changes in soil microbial biomass following insect infestation and pathogen-induced tree mortality were non-significant, although biotic disturbances were poorly represented in the literature. When measured separately, fungal and bacterial responses to disturbances mirrored the response of the microbial community as a whole. Changes in microbial abundance following disturbance were significantly positively correlated with changes in microbial respiration. We propose that the differential effect of abiotic and biotic disturbances on microbial biomass may be attributable to differences in soil disruption and organic C removal from forests among disturbance types. Altogether, these results suggest that abiotic forest disturbances may significantly decrease soil microbial abundance, with corresponding consequences for microbial respiration. Further studies are needed on the effect of biotic disturbances on forest soil microbial communities and soil C dynamics. PMID:23801985

  6. Standing crop and aboveground biomass partitioning of a dwarf mangrove forest in Taylor River Slough, Florida

    USGS Publications Warehouse

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

    2004-01-01

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

  7. Emergent Patterns of Forest Biomass Production from Across and within a Micro-Network

    NASA Astrophysics Data System (ADS)

    Pederson, N.; Martin Benito, D.; Bishop, D. A.; Dawson, A.; Dietze, M.; Druckenbrod, D.; Dye, A.; Gonzalez, A. C.; Hessl, A. E.; Martin Fernandez, J.; McLachlan, J. S.; Paciorek, C. J.; Poulter, B.; Williams, J. W.

    2014-12-01

    Many factors drive short- and long-term trends in forest biomass production. Replication at multiple scales, from within individual trees up to continental scales, is necessary to determine factors of growth and at what scale they are most important. Here we report on patterns of biomass production from within and across a micro-network of three forests in the northeastern US. Each forest has different histories and species composition, but each is within a similar climatological setting, which gives insight on important factors of short- and long-term patterns of forest production. One emergent pattern is that two forests are showing a large uptick in production over the last decade. Coincident to this uptick, late-season biomass production is showing a significant increase, even among 150-200+ year old trees. The third forest experienced a severe ice storm in the early-Aughts that paused a three-decade trend of increasing production. In the least diverse forest, the most dominant species drives most of the annual to decadal trend in production. In the most diverse forest, no one species appears to be driving landscape-level production, yet the emergent pattern of production reflects not only drought and pluvial events, but the impact of invasive species and the ice storm. Variation in annual biomass production for most species is strongly related to annual variations in soil moisture. Interestingly at the species level, coherency of growth among yellow birch is lower in the oldest forest in which is it is common versus the youngest forest. Differences in coherency suggest different drivers operating at different scales. Growth of red maple is also driven by moisture, but competition appears to be driving a long-term decline of individuals below the canopy. The decline begins soon after a severe defoliation event. In this same forest, however, significant wetting and warming over the last two decades appears to have reduced some of the climatic constraints on red

  8. Environmental risks of utilizing crop and forest residues for biomass energy

    SciTech Connect

    Pimentel, D.; Fast, S.; Gallahan, D.; Moran, M.A.

    1983-08-01

    Crop and forest residues are a valuable biomass resource for natural, agricultural, and forest ecosystems. These residues are essential to protect the soil from erosion and rapid water runoff and to maintain soil organic matter and nutrients. Thus, only an estimated 20% of the total residues remaining after harvest can be utilized for conversion because of environmental limitations and the impracticality of harvesting residues on some lands. Although the potential contribution of biomass energy to U.S. energy needs is relatively small, it is renewable energy (assuming no environmental degradation) and therefore has some long term value to the nation's energy program.

  9. Tropical forest biomass and successional age class relationships to a vegetation index derived from Landsat TM data

    NASA Technical Reports Server (NTRS)

    Sader, Steven A.; Waide, Robert B.; Lawrence, William T.; Joyce, Armond T.

    1989-01-01

    Forest stand structure and biomass data were collected using conventional forest inventory techniques in tropical, subtropical, and warm temperate forest biomes. The feasibility of detecting tropical forest successional age class and total biomass differences using Landsat-Thematic mapper (TM) data, was evaluated. The Normalized Difference Vegetation Index (NDVI) calculated from Landsat-TM data were not significantly correlated with forest regeneration age classes in the mountain terrain of the Luquillo Experimental Forest, Puerto Rico. The low sun angle and shadows cast on steep north and west facing slopes reduced spectral reflectance values recorded by TM orbital altitude. The NDVI, calculated from low altitude aircraft scanner data, was significatly correlated with forest age classes. However, analysis of variance suggested that NDVI differences were not detectable for successional forests older than approximately 15-20 years. Also, biomass differences in young successional tropical forest were not detectable using the NDVI. The vegetation index does not appear to be a good predictor of stand structure variables (e.g., height, diameter of main stem) or total biomass in uneven age, mixed broadleaf forest. Good correlation between the vegetation index and low biomass in even age pine plantations were achieved for a warm temperate study site. The implications of the study for the use of NDVI for forest structure and biomass estimation are discussed.

  10. Carbon carry capacity and carbon sequestration potential in China based on an integrated analysis of mature forest biomass.

    PubMed

    Liu, YingChun; Yu, GuiRui; Wang, QiuFeng; Zhang, YangJian; Xu, ZeHong

    2014-12-01

    Forests play an important role in acting as a carbon sink of terrestrial ecosystem. Although global forests have huge carbon carrying capacity (CCC) and carbon sequestration potential (CSP), there were few quantification reports on Chinese forests. We collected and compiled a forest biomass dataset of China, a total of 5841 sites, based on forest inventory and literature search results. From the dataset we extracted 338 sites with forests aged over 80 years, a threshold for defining mature forest, to establish the mature forest biomass dataset. After analyzing the spatial pattern of the carbon density of Chinese mature forests and its controlling factors, we used carbon density of mature forests as the reference level, and conservatively estimated the CCC of the forests in China by interpolation methods of Regression Kriging, Inverse Distance Weighted and Partial Thin Plate Smoothing Spline. Combining with the sixth National Forest Resources Inventory, we also estimated the forest CSP. The results revealed positive relationships between carbon density of mature forests and temperature, precipitation and stand age, and the horizontal and elevational patterns of carbon density of mature forests can be well predicted by temperature and precipitation. The total CCC and CSP of the existing forests are 19.87 and 13.86 Pg C, respectively. Subtropical forests would have more CCC and CSP than other biomes. Consequently, relying on forests to uptake carbon by decreasing disturbance on forests would be an alternative approach for mitigating greenhouse gas concentration effects besides afforestation and reforestation.

  11. Biotic and abiotic controls on the distribution of tropical forest aboveground biomass

    NASA Astrophysics Data System (ADS)

    Saatchi, S. S.; Schimel, D.; Keller, M. M.; Chambers, J. Q.; Dubayah, R.; Duffy, P.; Yu, Y.; Robinson, C. M.; Chowdhury, D.; Yang, Y.

    2013-12-01

    AUTHOR: Sassan Saatchi1,2, Yan Yang2, Diya Chowdhury2, Yifan Yu2, Chelsea Robinson2, David Schimel1, Paul Duffy3, Michael Keller4, Ralph Dubayah5, Jeffery Chambers6 1. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA USA 2. Institute of Environment and Sustainability, University of California, Los Angeles, CA, USA 3. Neptune and Company, Inc. Denver, CO, USA 4. International Institute of Tropical Forestry & International Programs, USDA Forest Service, Campinas, Brazil 5. Department of Geography, University of Maryland, College Park, MD, USA 6. Department of Geography, University of California, Berkeley, CA, USA ABSTRACT BODY: In recent years, climate change policies and scientific research created a widespread interest in quantify the carbon stock and changes of global tropical forests extending from forest patches to national and regional scales. Using a combination of inventory data from field plots and forest structure from spaceborne Lidar data, we examine the main controls on the distribution of tropical forest biomass. Here, we concentrate on environmental and landscape variables (precipitation, temperature, topography, and soil), and biotic variables such as functional traits (density of large trees, and wood specific gravity). The analysis is performed using global bioclimatic variables for precipitation and temperature, SRTM data for topographical variables (elevation and ruggedness), and global harmonized soil data for soil type and texture. For biotic variables, we use the GLAS Lidar data to quantify the distribution of large trees, a combined field and remote sensing data for distribution of tree wood specific gravity. The results show that climate variables such as precipitation of dry season can explain the heterogeneity of forest biomass over the landscape but cannot predict the biomass variability significantly and particularly for high biomass forests. Topography such as elevation and ruggedness along with temperature can

  12. Accounting for Biomass Carbon Stock Change Due to Wildfire in Temperate Forest Landscapes in Australia

    PubMed Central

    Keith, Heather; Lindenmayer, David B.; Mackey, Brendan G.; Blair, David; Carter, Lauren; McBurney, Lachlan; Okada, Sachiko; Konishi-Nagano, Tomoko

    2014-01-01

    Carbon stock change due to forest management and disturbance must be accounted for in UNFCCC national inventory reports and for signatories to the Kyoto Protocol. Impacts of disturbance on greenhouse gas (GHG) inventories are important for many countries with large forest estates prone to wildfires. Our objective was to measure changes in carbon stocks due to short-term combustion and to simulate longer-term carbon stock dynamics resulting from redistribution among biomass components following wildfire. We studied the impacts of a wildfire in 2009 that burnt temperate forest of tall, wet eucalypts in south-eastern Australia. Biomass combusted ranged from 40 to 58 tC ha−1, which represented 6–7% and 9–14% in low- and high-severity fire, respectively, of the pre-fire total biomass carbon stock. Pre-fire total stock ranged from 400 to 1040 tC ha−1 depending on forest age and disturbance history. An estimated 3.9 TgC was emitted from the 2009 fire within the forest region, representing 8.5% of total biomass carbon stock across the landscape. Carbon losses from combustion were large over hours to days during the wildfire, but from an ecosystem dynamics perspective, the proportion of total carbon stock combusted was relatively small. Furthermore, more than half the stock losses from combustion were derived from biomass components with short lifetimes. Most biomass remained on-site, although redistributed from living to dead components. Decomposition of these components and new regeneration constituted the greatest changes in carbon stocks over ensuing decades. A critical issue for carbon accounting policy arises because the timeframes of ecological processes of carbon stock change are longer than the periods for reporting GHG inventories for national emissions reductions targets. Carbon accounts should be comprehensive of all stock changes, but reporting against targets should be based on human-induced changes in carbon stocks to incentivise mitigation activities

  13. Accounting for biomass carbon stock change due to wildfire in temperate forest landscapes in Australia.

    PubMed

    Keith, Heather; Lindenmayer, David B; Mackey, Brendan G; Blair, David; Carter, Lauren; McBurney, Lachlan; Okada, Sachiko; Konishi-Nagano, Tomoko

    2014-01-01

    Carbon stock change due to forest management and disturbance must be accounted for in UNFCCC national inventory reports and for signatories to the Kyoto Protocol. Impacts of disturbance on greenhouse gas (GHG) inventories are important for many countries with large forest estates prone to wildfires. Our objective was to measure changes in carbon stocks due to short-term combustion and to simulate longer-term carbon stock dynamics resulting from redistribution among biomass components following wildfire. We studied the impacts of a wildfire in 2009 that burnt temperate forest of tall, wet eucalypts in south-eastern Australia. Biomass combusted ranged from 40 to 58 tC ha(-1), which represented 6-7% and 9-14% in low- and high-severity fire, respectively, of the pre-fire total biomass carbon stock. Pre-fire total stock ranged from 400 to 1040 tC ha(-1) depending on forest age and disturbance history. An estimated 3.9 TgC was emitted from the 2009 fire within the forest region, representing 8.5% of total biomass carbon stock across the landscape. Carbon losses from combustion were large over hours to days during the wildfire, but from an ecosystem dynamics perspective, the proportion of total carbon stock combusted was relatively small. Furthermore, more than half the stock losses from combustion were derived from biomass components with short lifetimes. Most biomass remained on-site, although redistributed from living to dead components. Decomposition of these components and new regeneration constituted the greatest changes in carbon stocks over ensuing decades. A critical issue for carbon accounting policy arises because the timeframes of ecological processes of carbon stock change are longer than the periods for reporting GHG inventories for national emissions reductions targets. Carbon accounts should be comprehensive of all stock changes, but reporting against targets should be based on human-induced changes in carbon stocks to incentivise mitigation activities.

  14. 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.

  15. A Preliminary Study of Biomass Estimation of Boreal Forest in Alaska Using ALOS PALSAR Polarimetric Images

    NASA Astrophysics Data System (ADS)

    Li, S.; Wurtz, T.; Gens, R.

    2007-12-01

    A reliable forest biomass determination is essential for understanding and modeling ecosystem dynamics, regional and global Carbon-fluxes, and their implications in global climate and environmental changes. The full- (HH+HV+VV+VH) and 2-polarization (HH+HV) information available from the Phased Array type L-band Synthetic Aperture Radar (PALSAR) on the newly launched Japanese satellite, Advanced Land Observation Satellite (ALOS), offers a great opportunity for estimating forest biomass from Space. We investigate ALOS PALSAR application in forest biomass estimation through two approaches. The first involves SAR polarimetry. Multiple scattering within forest, especially within forest canopy causes change of vibration direction in return radar signals, resulting in increase of the proportion of cross-polarization (i.e., HV and VH) components. Consequently, the degree of polarization (the ratio of co-polarized received power-HH+VV-over the total received power) thus decreases with increasing biomass. The second approach involves with polarization phase difference (PPD) and its standard deviation. These two parameters increase with increase in multiple scattering. Therefore, they are also indicators of higher biomass. ALOS PALSAR data sets at test sites at Bonanza Creek Experimental Forest, Alaska, were acquired through the Americas ALOS Data Node (AADN) at Alaska Satellite Facility. Interferometric tools are used in data processing to relate complex images in different polarizations. The resulting interferometric phase images are used for PPD and coherence images for deviations in PPD. Analysis is made through comparison of the interferometric-based patterns of PPD and its standard deviation with ground truth gathered through previous field campaigns.

  16. Tree Biomass Allocation and Its Model Additivity for Casuarina equisetifolia in a Tropical Forest of Hainan Island, China

    PubMed Central

    Xue, Yang; Yang, Zhongyang; Wang, Xiaoyan; Lin, Zhipan; Li, Dunxi; Su, Shaofeng

    2016-01-01

    Casuarina equisetifolia is commonly planted and used in the construction of coastal shelterbelt protection in Hainan Island. Thus, it is critical to accurately estimate the tree biomass of Casuarina equisetifolia L. for forest managers to evaluate the biomass stock in Hainan. The data for this work consisted of 72 trees, which were divided into three age groups: young forest, middle-aged forest, and mature forest. The proportion of biomass from the trunk significantly increased with age (P<0.05). However, the biomass of the branch and leaf decreased, and the biomass of the root did not change. To test whether the crown radius (CR) can improve biomass estimates of C. equisetifolia, we introduced CR into the biomass models. Here, six models were used to estimate the biomass of each component, including the trunk, the branch, the leaf, and the root. In each group, we selected one model among these six models for each component. The results showed that including the CR greatly improved the model performance and reduced the error, especially for the young and mature forests. In addition, to ensure biomass additivity, the selected equation for each component was fitted as a system of equations using seemingly unrelated regression (SUR). The SUR method not only gave efficient and accurate estimates but also achieved the logical additivity. The results in this study provide a robust estimation of tree biomass components and total biomass over three groups of C. equisetifolia. PMID:27002822

  17. Tree Biomass Allocation and Its Model Additivity for Casuarina equisetifolia in a Tropical Forest of Hainan Island, China.

    PubMed

    Xue, Yang; Yang, Zhongyang; Wang, Xiaoyan; Lin, Zhipan; Li, Dunxi; Su, Shaofeng

    2016-01-01

    Casuarina equisetifolia is commonly planted and used in the construction of coastal shelterbelt protection in Hainan Island. Thus, it is critical to accurately estimate the tree biomass of Casuarina equisetifolia L. for forest managers to evaluate the biomass stock in Hainan. The data for this work consisted of 72 trees, which were divided into three age groups: young forest, middle-aged forest, and mature forest. The proportion of biomass from the trunk significantly increased with age (P<0.05). However, the biomass of the branch and leaf decreased, and the biomass of the root did not change. To test whether the crown radius (CR) can improve biomass estimates of C. equisetifolia, we introduced CR into the biomass models. Here, six models were used to estimate the biomass of each component, including the trunk, the branch, the leaf, and the root. In each group, we selected one model among these six models for each component. The results showed that including the CR greatly improved the model performance and reduced the error, especially for the young and mature forests. In addition, to ensure biomass additivity, the selected equation for each component was fitted as a system of equations using seemingly unrelated regression (SUR). The SUR method not only gave efficient and accurate estimates but also achieved the logical additivity. The results in this study provide a robust estimation of tree biomass components and total biomass over three groups of C. equisetifolia.

  18. Regional forest biomass estimation using ICESat/GLAS spaceborne LiDAR

    NASA Astrophysics Data System (ADS)

    Hayashi, M.; Saigusa, N.; Habura, B.; Sawada, Y.; Yamagata, Y.; Hirano, T.; Ichii, K.

    2015-12-01

    Spaceborne LiDAR can observe vertical structure of forests and provide a means for accurate forest monitoring, therefore, it may meet the growing demand of forest resources monitoring on a large scale. This study aims to clarify the potential of ICESat/GLAS, which had been the only spaceborne LiDAR up to now, for forest resources monitoring on a regional scale. The study areas were three regions: Hokkaido Island in Japan (cool-temperate forest), Borneo Island (tropical forest) and Siberia (boreal forest). Firstly, we conducted field measurements at 106 points in Hokkaido and 37 points in Borneo to measure the average canopy height (Lorey's height) and the above-ground biomass (AGB) for each GLAS-footprint, then, we developed some models to estimate canopy height and AGB from the GLAS waveform parameters. Next, we applied the developed models to the GLAS data which were 14,000 points in Hokkaido, and 130,000 points in Borneo, to estimate canopy height and AGB on a regional scale. As a result, we clarified the forest condition concerning canopy height and AGB for each region, namely, the average value, the comparison between the average of each forest type, and the spatial distribution. Furthermore, we detected the AGB change over the years (forest degradation) and estimated the forest loss rate of 1.6% yr-1 in Borneo. Next, we applied the developed models in Hokkaido to the 1,600,000 points GLAS data observed in Siberia. As a result, we clarified that the average AGB in Siberia was a remarkable low value as compared with those in Hokkaido and Borneo, and that the AGB change over the years (forest degradation) was significant in the southern region of western Siberia. This study showed that spaceborne LiDAR had an ability of forest resources monitoring on a regional scale for various forests over the world.

  19. On the potential of long wavelength imaging radars for mapping vegetation types and woody biomass in tropical rain forests

    NASA Technical Reports Server (NTRS)

    Rignot, Eric J.; Zimmermann, Reiner; Oren, Ram

    1995-01-01

    In the tropical rain forests of Manu, in Peru, where forest biomass ranges from 4 kg/sq m in young forest succession up to 100 kg/sq m in old, undisturbed floodplain stands, the P-band polarimetric radar data gathered in June of 1993 by the AIRSAR (Airborne Synthetic Aperture Radar) instrument separate most major vegetation formations and also perform better than expected in estimating woody biomass. The worldwide need for large scale, updated biomass estimates, achieved with a uniformly applied method, as well as reliable maps of land cover, justifies a more in-depth exploration of long wavelength imaging radar applications for tropical forests inventories.

  20. Thinning intensity influences on soil microbial and inorganic nitrogen in Pinus densiflora forests, central Korea

    NASA Astrophysics Data System (ADS)

    Kim, S.; Li, G.; Yun, H. M.; Han, S. H.; Lee, J.; Kim, C.; Lee, S. T.; Son, Y.

    2015-12-01

    With growing considerations for sustainable forest management, examining thinning effects on forest ecosystems becomes one of the principal research focuses. Soil microbial biomass and inorganic nitrogen (N) have, particularly, received increasing attentions, as they are the relevant indices for N availability in forests. Here, we investigated the influences of thinning on soil microbial biomass N (MBN) and inorganic N (NH4+ and NO3-) in two Pinus densiflora forests, central Korea. The thinning from below with different intensities based on stand density (site 1: control, 20%, and 30% thinning; site 2: control, 39%, and 74% thinning) was applied in 2008, and MBN, NH4+, and NO3- at 0-10 cm depth were measured seven years after thinning. The MBN, NH4+, and NO3- concentrations (mg kg-1) of the site 1 were 69.8, 9.8, and 6.3 in the control, 94.6, 9.3, and 4.0 in the 20% thinning plot, and 97.2, 8.4, and 5.2 in the 30% thinning plot, respectively. On the other hand, those of the site 2 were 34.5, 5.4, and 6.3 in the control, 37.3, 4.7, and 7.8 in the 39% thinning plot, and 44.4, 4.4, and 9.2 in the 74% thinning plot, respectively. The MBN of the thinning plots tended to be higher compared to those of the controls, although the analysis of variance reported the significant difference only for the MBN in the site 1 (P<0.05). This might be attributed to the incorporation of organic matter from the introduced thinning residues and from the increased understory vegetation following thinning. However, no significant difference was found for the NH4+ and NO3- (P>0.05). The results of the present study show that the application of thinning could differently affect MBN and inorganic N; accordingly, this difference might alter N availability of the study sites. This study was supported by Forest Practice Research Center, Korea Forest Research Institute.

  1. Dispersal limitation induces long-term biomass collapse in overhunted Amazonian forests

    PubMed Central

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

    2016-01-01

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

  2. Relationships of biomass, nutrient pools and anthropogenic activities in Amazonian forests

    SciTech Connect

    Kauffman, J.B.; Cummings, D.L.; Rabbitt, R.E.; Ward, D.E. Forest Service, Missoula, MT )

    1993-06-01

    There are two general patterns associated with deforestation in Amazonia: shifting cultivation where forests are felled and burned every 4-10 years; and pasture conversion where burning occurs every 1-3 years. The former results in a more rapid rate of nutrient loss due to fire frequency and the greater susceptibility of aboveground nutrient pools to volatilization. Along the gradient from primary forest to burned degraded pasture or third-growth forest, aboveground biomass decreased from 434 Mg ha[sup [minus]1] to <8 Mg ha[sup [minus]1]. However, tremendous variability exists in the biomass, nutrient pools, and fire effects in Terra Firme forests, second-growth forests (Capoiera) and pastures. For example, N losses from primary forests ranged from 500 to 1380 kg ha[sup [minus]1], losses from Capoiera ranged from 300 to 400 kg ha[sup [minus]1] and losses from pastures were 200 to >500 kg ha[sup [minus]1]. Clearly these land use practices result in a significant transfer of C to the atmosphere, are not sustainable for human uses and may exacerbate difficulties in forest restoration.

  3. Dispersal limitation induces long-term biomass collapse in overhunted Amazonian forests.

    PubMed

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

    2016-01-26

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

  4. Changes in forest biomass carbon storage in China between 1949 and 1998.

    PubMed

    Fang, J; Chen, A; Peng, C; Zhao, S; Ci, L

    2001-06-22

    The location and mechanisms responsible for the carbon sink in northern mid-latitude lands are uncertain. Here, we used an improved estimation method of forest biomass and a 50-year national forest resource inventory in China to estimate changes in the storage of living biomass between 1949 and 1998. Our results suggest that Chinese forests released about 0.68 petagram of carbon between 1949 and 1980, for an annual emission rate of 0.022 petagram of carbon. Carbon storage increased significantly after the late 1970s from 4.38 to 4.75 petagram of carbon by 1998, for a mean accumulation rate of 0.021 petagram of carbon per year, mainly due to forest expansion and regrowth. Since the mid-1970s, planted forests (afforestation and reforestation) have sequestered 0.45 petagram of carbon, and their average carbon density increased from 15.3 to 31.1 megagrams per hectare, while natural forests have lost an additional 0.14 petagram of carbon, suggesting that carbon sequestration through forest management practices addressed in the Kyoto Protocol could help offset industrial carbon dioxide emissions.

  5. Efficacy of generic allometric equations for estimating biomass: a test in Japanese natural forests.

    PubMed

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

    2015-07-01

    Accurate estimation of tree and forest biomass is key to evaluating forest ecosystem functions and the global carbon cycle. Allometric equations that estimate tree biomass from a set of predictors, such as stem diameter and tree height, are commonly used. Most allometric equations are site specific, usually developed from a small number of trees harvested in a small area, and are either species specific or ignore interspecific differences in allometry. Due to lack of site-specific allometries, local equations are often applied to sites for which they were not originally developed (foreign sites), sometimes leading to large errors in biomass estimates. In this study, we developed generic allometric equations for aboveground biomass and component (stem, branch, leaf, and root) biomass using large, compiled data sets of 1203 harvested trees belonging to 102 species (60 deciduous angiosperm, 32 evergreen angiosperm, and 10 evergreen gymnosperm species) from 70 boreal, temperate, and subtropical natural forests in Japan. The best generic equations provided better biomass estimates than did local equations that were applied to foreign sites. The best generic equations included explanatory variables that represent interspecific differences in allometry in addition to stem diameter, reducing error by 4-12% compared to the generic equations that did not include the interspecific difference. Different explanatory variables were selected for different components. For aboveground and stem biomass, the best generic equations had species-specific wood specific gravity as an explanatory variable. For branch, leaf, and root biomass, the best equations had functional types (deciduous angiosperm, evergreen angiosperm, and evergreen gymnosperm) instead of functional traits (wood specific gravity or leaf mass per area), suggesting importance of other traits in addition to these traits, such as canopy and root architecture. Inclusion of tree height in addition to stem diameter improved

  6. Landscape Scale Height, Biomass and Carbon Estimation of Mangrove Forests with SRTM Elevation Data

    NASA Astrophysics Data System (ADS)

    Fatoyinbo, T. E.; Washington-Allen, R.; Simard, M.; Shugart, H. H.

    2006-12-01

    Mangroves are salt tolerant plants that grow within the intertidal zone along tropical and sub-tropical coasts and estuaries. They are important barriers for mitigating the cataclysmic coastal effects of climatic events and are one of the most productive ecosystems worldwide. We produced a countrywide map of mean tree height of mangrove forests for Mozambique using elevation data derived from the Shuttle Radar Topography Mission (SRTM). The SRTM data was calibrated using a Landsat Thematic Mapper derived land cover map, field collected tree-height data, and coarse resolution (1-km) GTOPO 30 digital elevation data. The land cover map and the SRTM-derived mangrove height map showed an increase in both mangrove forest area and height from the South of the country to the North, along the 2700 km coastline. We then produced stand-specific height- biomass relationships from field-derived measures of tree height and diameter. These allometric equations permitted the calculation of total aboveground biomass and total aboveground Carbon stored within the mangrove forests. The resulting biomass and Carbon map we produced show larger biomass and Carbon storage in lower latitudes and in forests with a steady input of freshwater.

  7. REGIONAL ESTIMATION OF CURRENT AND FUTURE FOREST BIOMASS. (R828785)

    EPA Science Inventory

    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 exc...

  8. Estimating aboveground biomass of broadleaved woody plants in the understory of Florida Keys pine forests

    USGS Publications Warehouse

    Sah, J.P.; Ross, M.S.; Koptur, S.; Snyder, J.R.

    2004-01-01

    Species-specific allometric equations that provide estimates of biomass from measured plant attributes are currently unavailable for shrubs common to South Florida pine rocklands, where fire plays an important part in shaping the structure and function of ecosystems. We developed equations to estimate total aboveground biomass and fine fuel of 10 common hardwood species in the shrub layer of pine forests of the lower Florida Keys. Many equations that related biomass categories to crown area and height were significant (p < 0.05), but the form and variables comprising the best model varied among species. We applied the best-fit regression models to structural information from the shrub stratum in 18 plots on Big Pine Key, the most extensive pine forest in the Keys. Estimates based on species-specific equations indicated clearly that total aboveground shrub biomass and shrub fine fuel increased with time since last fire, but the relationships were non-linear. The relative proportion of biomass constituted by the major species also varied with stand age. Estimates based on mixed-species regressions differed slightly from estimates based on species-specific models, but the former could provide useful approximations in similar forests where species-specific regressions are not yet available. ?? 2004 Elsevier B.V. All rights reserved.

  9. Detecting forest structure and biomass with C-band multipolarization radar - Physical model and field tests

    NASA Technical Reports Server (NTRS)

    Westman, Walter E.; Paris, Jack F.

    1987-01-01

    The ability of C-band radar (4.75 GHz) to discriminate features of forest structure, including biomass, is tested using a truck-mounted scatterometer for field tests on a 1.5-3.0 m pygmy forest of cypress (Cupressus pygmaea) and pine (Pinus contorta ssp, Bolanderi) near Mendocino, CA. In all, 31 structural variables of the forest are quantified at seven sites. Also measured was the backscatter from a life-sized physical model of the pygmy forest, composed of nine wooden trees with 'leafy branches' of sponge-wrapped dowels. This model enabled independent testing of the effects of stem, branch, and leafy branch biomass, branch angle, and moisture content on radar backscatter. Field results suggested that surface area of leaves played a greater role in leaf scattering properties than leaf biomass per se. Tree leaf area index was strongly correlated with vertically polarized power backscatter (r = 0.94; P less than 0.01). Field results suggested that the scattering role of leaf water is enhanced as leaf surface area per unit leaf mass increases; i.e., as the moist scattering surfaces become more dispersed. Fog condensate caused a measurable rise in forest backscatter, both from surface and internal rises in water content. Tree branch mass per unit area was highly correlated with cross-polarized backscatter in the field (r = 0.93; P less than 0.01), a result also seen in the physical model.

  10. Quantifying above- and belowground biomass carbon loss with forest conversion in tropical lowlands of Sumatra (Indonesia).

    PubMed

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

    2015-10-01

    Natural forests in South-East Asia have been extensively converted into other land-use systems in the past decades and still show high deforestation rates. Historically, lowland forests have been converted into rubber forests, but more recently, the dominant conversion is into oil palm plantations. While it is expected that the large-scale conversion has strong effects on the carbon cycle, detailed studies quantifying carbon pools and total net primary production (NPPtotal ) in above- and belowground tree biomass in land-use systems replacing rainforest (incl. oil palm plantations) are rare so far. We measured above- and belowground carbon pools in tree biomass together with NPPtotal in natural old-growth forests, 'jungle rubber' agroforests under natural tree cover, and rubber and oil palm monocultures in Sumatra. In total, 32 stands (eight plot replicates per land-use system) were studied in two different regions. Total tree biomass in the natural forest (mean: 384 Mg ha(-1) ) was more than two times higher than in jungle rubber stands (147 Mg ha(-1) ) and >four times higher than in monoculture rubber and oil palm plantations (78 and 50 Mg ha(-1) ). NPPtotal was higher in the natural forest (24 Mg ha(-1)  yr(-1) ) than in the rubber systems (20 and 15 Mg ha(-1)  yr(-1) ), but was highest in the oil palm system (33 Mg ha(-1)  yr(-1) ) due to very high fruit production (15-20 Mg ha(-1)  yr(-1) ). NPPtotal was dominated in all systems by aboveground production, but belowground productivity was significantly higher in the natural forest and jungle rubber than in plantations. We conclude that conversion of natural lowland forest into different agricultural systems leads to a strong reduction not only in the biomass carbon pool (up to 166 Mg C ha(-1) ) but also in carbon sequestration as carbon residence time (i.e. biomass-C:NPP-C) was 3-10 times higher in the natural forest than in rubber and oil palm plantations.

  11. Model Effects on GLAS-Based Regional Estimates of Forest Biomass and Carbon

    NASA Technical Reports Server (NTRS)

    Nelson, Ross

    2008-01-01

    ICESat/GLAS waveform data are used to estimate biomass and carbon on a 1.27 million sq km study area. the Province of Quebec, Canada, below treeline. The same input data sets and sampling design are used in conjunction with four different predictive models to estimate total aboveground dry forest biomass and forest carbon. The four models include nonstratified and stratified versions of a multiple linear model where either biomass or (square root of) biomass serves as the dependent variable. The use of different models in Quebec introduces differences in Provincial biomass estimates of up to 0.35 Gt (range 4.942+/-0.28 Gt to 5.29+/-0.36 Gt). The results suggest that if different predictive models are used to estimate regional carbon stocks in different epochs, e.g., y2005, y2015, one might mistakenly infer an apparent aboveground carbon "change" of, in this case, 0.18 Gt, or approximately 7% of the aboveground carbon in Quebec, due solely to the use of different predictive models. These findings argue for model consistency in future, LiDAR-based carbon monitoring programs. Regional biomass estimates from the four GLAS models are compared to ground estimates derived from an extensive network of 16,814 ground plots located in southern Quebec. Stratified models proved to be more accurate and precise than either of the two nonstratified models tested.

  12. Estimates of forest biomass carbon storage inLiaoning Province of Northeast China: a review and assessment.

    PubMed

    Yu, Dapao; Wang, Xiaoyu; Yin, You; Zhan, Jinyu; Lewis, Bernard J; Tian, Jie; Bao, Ye; Zhou, Wangming; Zhou, Li; Dai, Limin

    2014-01-01

    Accurate estimates of forest carbon storage and changes in storage capacity are critical for scientific assessment of the effects of forest management on the role of forests as carbon sinks. Up to now, several studies reported forest biomass carbon (FBC) in Liaoning Province based on data from China's Continuous Forest Inventory, however, their accuracy were still not known. This study compared estimates of FBC in Liaoning Province derived from different methods. We found substantial variation in estimates of FBC storage for young and middle-age forests. For provincial forests with high proportions in these age classes, the continuous biomass expansion factor method (CBM) by forest type with age class is more accurate and therefore more appropriate for estimating forest biomass. Based on the above approach designed for this study, forests in Liaoning Province were found to be a carbon sink, with carbon stocks increasing from 63.0 TgC in 1980 to 120.9 TgC in 2010, reflecting an annual increase of 1.9 TgC. The average carbon density of forest biomass in the province has increased from 26.2 Mg ha(-1) in 1980 to 31.0 Mg ha(-1) in 2010. While the largest FBC occurred in middle-age forests, the average carbon density decreased in this age class during these three decades. The increase in forest carbon density resulted primarily from the increased area and carbon storage of mature forests. The relatively long age interval in each age class for slow-growing forest types increased the uncertainty of FBC estimates by CBM-forest type with age class, and further studies should devote more attention to the time span of age classes in establishing biomass expansion factors for use in CBM calculations.

  13. [Spatial distribution characteristics of the biomass and carbon storage of Qinghai spruce (Picea crassifolia) forests in Qilian Mountains].

    PubMed

    Peng, Shou-zhang; Zhao, Chuan-yan; Zheng, Xiang-lin; Xu, Zhong-lin; He, Lei

    2011-07-01

    This paper estimated the biomass and carbon storage and their spatial distributions of Qinghai spruce (Picea crassifolia) forests in Qilian Mountains, based on the field investigation, forest map, and meteorological data, and with the help of GIS technology. In 2008, the biomass of the forests was averagely 209.24 t x hm(-2), with a total biomass of 3.4 x 10(7) t. Due to the difference of water and thermal condition, there existed great differences in the biomass of Qinghai spruce within the Mountains. The biomass increased by 3.12 t x hm(-2) with increasing 1 degrees longitude and decreased by 3.8 t x hm(-2) with increasing 1 degrees latitude, and decreased by 0.05 t x hm(-2) with the elevation increasing 100 m. The carbon density of the forests ranged from 70.4 to 131.1 t x hm(-2), averagely 109.8 t x hm(-2), and the average carbon density was 83.8 t x hm(-2) for the young forest, 109.6 t x hm(-2) for the middle age forest, 122 t x hm(-2) for the near-mature forest, 124.2 t x hm(-2) for the mature forest, and 117.1 t x hm(-2) for the over-mature forest. The total carbon storage of Qinghai spruce forests in the study area was 1.8 x 10(7) t.

  14. Improving simulated Amazon forest biomass and productivity by including spatial variation in biophysical parameters

    NASA Astrophysics Data System (ADS)

    Castanho, A. D. A.; Coe, M. T.; Costa, M. H.; Malhi, Y.; Galbraith, D.; Quesada, C. A.

    2013-04-01

    Dynamic vegetation models forced with spatially homogeneous biophysical parameters are capable of producing average productivity and biomass values for the Amazon basin forest biome that are close to the observed estimates, but these models are unable to reproduce observed spatial variability. Recent observational studies have shown substantial regional spatial variability of above-ground productivity and biomass across the Amazon basin, which is believed to be primarily driven by a combination of soil physical and chemical properties. In this study, spatial heterogeneity of vegetation properties is added to the Integrated Biosphere Simulator (IBIS) land surface model, and the simulated productivity and biomass of the Amazon basin are compared to observations from undisturbed forest. The maximum RuBiCo carboxylation capacity (Vcmax) and the woody biomass residence time (τw) were found to be the most important properties determining the modeled spatial variation of above-ground woody net primary productivity and biomass, respectively. Spatial heterogeneity of these properties may lead to simulated spatial variability of 1.8 times in the woody net primary productivity (NPPw) and 2.8 times in the woody above-ground biomass (AGBw). The coefficient of correlation between the modeled and observed woody productivity improved from 0.10 with homogeneous parameters to 0.73 with spatially heterogeneous parameters, while the coefficient of correlation between the simulated and observed woody above-ground biomass improved from 0.33 to 0.88. The results from our analyses with the IBIS dynamic vegetation model demonstrated that using single values for key ecological parameters in the tropical forest biome severely limits simulation accuracy. Clearer understanding of the biophysical mechanisms that drive the spatial variability of carbon allocation, τw and Vcmax is necessary to achieve further improvements to simulation accuracy.

  15. Mapping landscape scale variations of forest structure, biomass, and productivity in Amazonia

    NASA Astrophysics Data System (ADS)

    Saatchi, S.; Malhi, Y.; Zutta, B.; Buermann, W.; Anderson, L. O.; Araujo, A. M.; Phillips, O. L.; Peacock, J.; Ter Steege, H.; Lopez Gonzalez, G.; Baker, T.; Arroyo, L.; Almeida, S.; Higuchi, N.; Killeen, T.; Monteagudo, A.; Neill, D.; Pitman, N.; Prieto, A.; Salomão, R.; Silva, N.; Vásquez Martínez, R.; Laurance, W.; Ramírez, H. A.

    2009-06-01

    Landscape and environmental variables such as topography, geomorphology, soil types, and climate are important factors affecting forest composition, structure, productivity, and biomass. Here, we combine a network of forest inventories with recently developed global data products from satellite observations in modeling the potential distributions of forest structure and productivity in Amazonia and examine how geomorphology, soil, and precipitation control these distributions. We use the RAINFOR network of forest plots distributed in lowland forests across Amazonia, and satellite observations of tree cover, leaf area index, phenology, moisture, and topographical variations. A maximum entropy estimation (Maxent) model is employed to predict the spatial distribution of several key forest structure parameters: basal area, fraction of large trees, fraction of palms, wood density, productivity, and above-ground biomass at 5 km spatial resolution. A series of statistical tests at selected thresholds as well as across all thresholds and jackknife analysis are used to examine the accuracy of distribution maps and the relative contributions of environmental variables. The final maps were interpreted using soil, precipitation, and geomorphological features of Amazonia and it was found that the length of dry season played a key role in impacting the distribution of all forest variables except the wood density. Soil type had a significant impact on the wood productivity. Most high productivity forests were distributed either on less infertile soils of western Amazonia and Andean foothills, on crystalline shields, and younger alluvial deposits. Areas of low elevation and high density of small rivers of Central Amazonia showed distinct features, hosting mainly forests with low productivity and smaller trees.

  16. Effects of harvesting forest biomass on water and climate regulation services: A synthesis of long-term ecosystem experiments in eastern North America

    USGS Publications Warehouse

    Caputo, Jesse; Beier, Colin D; Groffman, Peter M; Burns, Douglas A.; Beall, Frederick D; Hazlett, Paul W.; Yorks, Thad E

    2016-01-01

    Demand for woody biomass fuels is increasing amidst concerns about global energy security and climate change, but there may be negative implications of increased harvesting for forest ecosystem functions and their benefits to society (ecosystem services). Using new methods for assessing ecosystem services based on long-term experimental research, post-harvest changes in ten potential benefits were assessed for ten first-order northern hardwood forest watersheds at three long-term experimental research sites in northeastern North America. As expected, we observed near-term tradeoffs between biomass provision and greenhouse gas regulation, as well as tradeoffs between intensive harvest and the capacity of the forest to remediate nutrient pollution. In both cases, service provision began to recover along with the regeneration of forest vegetation; in the case of pollution remediation, the service recovered to pre-harvest levels within 10 years. By contrast to these two services, biomass harvesting had relatively nominal and transient impacts on other ecosystem services. Our results are sensitive to empirical definitions of societal demand, including methods for scaling societal demand to ecosystem units, which are often poorly resolved. Reducing uncertainty around these parameters can improve confidence in our results and increase their relevance for decision-making. Our synthesis of long-term experimental studies provides insights on the social-ecological resilience of managed forest ecosystems to multiple drivers of change.

  17. Mapping Biomass for REDD in the Largest Forest of Central Africa: the Democratic Republic of Congo

    NASA Astrophysics Data System (ADS)

    Shapiro, Aurelie; Saatchi, Sassan

    2014-05-01

    With the support of the International Climate Initiative (ICI) of the Federal Ministry of the Environment, Conservation, and Nuclear Security, the implementation of the German Development Bank KfW, the World Wide Fund for Nature (WWF) Germany, the University of California Los Angeles (UCLA) and local DRC partners will produce a national scale biomass map for the entire forest coverage of the Democratic Republic of Congo (DRC) along with feasibility assessments of different forest protection measures within a framework of a REDD+ model project. The « Carbon Map and Model (CO2M&M) » project will produce a national forest biomass map for the DRC, which will enable quantitative assessments of carbon stocks and emissions in the largest forest of the Congo Basin. This effort will support the national REDD (Reducing Emissions from Deforestation and Degradation) program in DRC, which plays a major role in sustainable development and poverty alleviation. This map will be developed from field data, complemented by airborne LiDAR (Light Detection and Ranging) and aerial photos, systematically sampled throughout the forests of the DRC and up-scaled to satellite images to accurately estimate carbon content in all forested areas. The second component of the project is to develop specific approaches for model REDD projects in key landscapes. This project represents the largest LiDAR-derived mapping effort in Africa, under unprecedented logistical constraints, which will provide one of the poorest nations in the world with the richest airborne and satellites derived datasets for analyzing forest structure, biomass and biodiversity.

  18. Local spatial structure of forest biomass and its consequences for remote sensing of carbon stocks

    NASA Astrophysics Data System (ADS)

    Réjou-Méchain, M.; Muller-Landau, H. C.; Detto, M.; Thomas, S. C.; Le Toan, T.; Saatchi, S. S.; Barreto-Silva, J. S.; Bourg, N. A.; Bunyavejchewin, S.; Butt, N.; Brockelman, W. Y.; Cao, M.; Cárdenas, D.; Chiang, J.-M.; Chuyong, G. B.; Clay, K.; Condit, R.; Dattaraja, H. S.; Davies, S. J.; Duque, A.; Esufali, S.; Ewango, C.; Fernando, R. H. S.; Fletcher, C. D.; Gunatilleke, I. A. U. N.; Hao, Z.; Harms, K. E.; Hart, T. B.; Hérault, B.; Howe, R. W.; Hubbell, S. P.; Johnson, D. J.; Kenfack, D.; Larson, A. J.; Lin, L.; Lin, Y.; Lutz, J. A.; Makana, J.-R.; Malhi, Y.; Marthews, T. R.; McEwan, R. W.; McMahon, S. M.; McShea, W. J.; Muscarella, R.; Nathalang, A.; Noor, N. S. M.; Nytch, C. J.; Oliveira, A. A.; Phillips, R. P.; Pongpattananurak, N.; Punchi-Manage, R.; Salim, R.; Schurman, J.; Sukumar, R.; Suresh, H. S.; Suwanvecho, U.; Thomas, D. W.; Thompson, J.; Uríarte, M.; Valencia, R.; Vicentini, A.; Wolf, A. T.; Yap, S.; Yuan, Z.; Zartman, C. E.; Zimmerman, J. K.; Chave, J.

    2014-12-01

    Advances in forest carbon mapping have the potential to greatly reduce uncertainties in the global carbon budget and to facilitate effective emissions mitigation strategies such as REDD+ (Reducing Emissions from Deforestation and Forest Degradation). Though broad-scale mapping is based primarily on remote sensing data, the accuracy of resulting forest carbon stock estimates depends critically on the quality of field measurements and calibration procedures. The mismatch in spatial scales between field inventory plots and larger pixels of current and planned remote sensing products for forest biomass mapping is of particular concern, as it has the potential to introduce errors, especially if forest biomass shows strong local spatial variation. Here, we used 30 large (8-50 ha) globally distributed permanent forest plots to quantify the spatial variability in aboveground biomass density (AGBD in Mg ha-1) at spatial scales ranging from 5 to 250 m (0.025-6.25 ha), and to evaluate the implications of this variability for calibrating remote sensing products using simulated remote sensing footprints. We found that local spatial variability in AGBD is large for standard plot sizes, averaging 46.3% for replicate 0.1 ha subplots within a single large plot, and 16.6% for 1 ha subplots. AGBD showed weak spatial autocorrelation at distances of 20-400 m, with autocorrelation higher in sites with higher topographic variability and statistically significant in half of the sites. We further show that when field calibration plots are smaller than the remote sensing pixels, the high local spatial variability in AGBD leads to a substantial "dilution" bias in calibration parameters, a bias that cannot be removed with standard statistical methods. Our results suggest that topography should be explicitly accounted for in future sampling strategies and that much care must be taken in designing calibration schemes if remote sensing of forest carbon is to achieve its promise.

  19. Above-ground biomass and structure of 260 African tropical forests

    PubMed Central

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

    2013-01-01

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

  20. Above-ground biomass and structure of 260 African tropical forests.

    PubMed

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

    2013-01-01

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

  1. Effects of phosphorus concentration and light intensity on the biomass composition of Arthrospira (Spirulina) platensis.

    PubMed

    Markou, Giorgos; Chatzipavlidis, Iordanis; Georgakakis, Dimitris

    2012-08-01

    This paper presents the effects of various phosphorus concentrations (10, 50, 250 and 500 mg l(-1) K(2)HPO(4)) on the biomass production and composition of Arthrospira (Spirulina) platensis in relation to light intensity (24, 42 and 60 μE m(-2) s(-1)). The maximum biomass production was 3,592 ± 392 mg l(-1) and this was observed in 250 mg l(-1) K(2)HPO(4) at 60 μE m(-2) s(-1) light intensity after 32 days of cultivation. A maximum specific growth rate (μ(max)) of 0.55 d(-1) was obtained in 500 mg l(-1) K(2)HPO(4) at 60 μE m(-2) s(-1). The protein, lipid and chlorophyll contents of the biomass varied from 33.59 to 60.57 %, 5.34 to 13.33 % and 0.78 to 2.00 %, respectively. The most significant finding was that phosphorus limitation (10 mg l(-1) K(2)HPO(4)) caused a drastic increase of the carbohydrate content (59.64 %). The effect of phosphorus limitation on the carbohydrate content was independent of the light intensity. The accumulated carbohydrates are proposed to be used as substrate for biofuel generation via one of the appropriate biomass energy conversion technologies. Also, it was observed that phosphorus removal is a function of biomass density, phosphorus concentration and light intensity.

  2. Analysis of results of biomass forest inventory in northeastern Amazon for development of REDD+ carbon project.

    PubMed

    Mello, Leonel N C; Sales, Marcio H R; Rosa, Luiz P

    2016-03-01

    In Brazil, a significant reduction in deforestation rates occurred during the last decade. In spite of that fact, the average annual rates are still too high, approximately 400.000 ha/year (INPE/Prodes). The projects of emissions reduction through avoided deforestation (REED+) are an important tool to reduce deforestation rates in Brazil. Understanding the amazon forest structure, in terms of biomass stock is key to design avoided deforestation strategies. In this work, we analyze data results from aboveground biomass of 1,019.346,27 hectares in the state of Pará. It was collected data from 16,722 trees in 83 random independent plots. It was tested 4 allometric equations, for DBH > 10cm: Brown et al. (1989), Brown and Lugo (1999), Chambers et al. (2000), Higuchi et al. (1998). It revealed that the biggest carbon stock of above ground biomass is stocked on the interval at DBH between 30cm and 80cm. This biomass compartment stocks 75.70% of total biomass in Higuchi et al. (1998) equation, 75.56% of total biomass in Brown et al. (1989) equation, 78.83% of total biomass in Chambers et al. (2000) equation, and 73.22% in Brown and Lugo (1999) equation.

  3. [Aboveground biomass input of Myristicaceae tree species in the Amazonian Forest in Peru].

    PubMed

    Ureta Adrianzén, Marisabel

    2015-03-01

    Amazonian forests are a vast storehouse of biodiversity and function as carbon sinks from biomass that accumulates in various tree species. In these forests, the taxa with the greatest contribution of biomass cannot be precisely defined, and the representative distribution of Myristicaceae in the Peruvian Amazon was the starting point for designing the present study, which aimed to quantify the biomass contribution of this family. For this, I analyzed the databases that corresponded to 38 sample units that were previously collected and that were provided by the TeamNetwork and RAINFOR organizations. The analysis consisted in the estimation of biomass using pre-established allometric equations, Kruskal-Wallis sample comparisons, interpolation-analysis maps, and nonparametric multidimensional scaling (NMDS). The results showed that Myristicaceae is the fourth most important biomass contributor with 376.97 Mg/ha (9.92 Mg/ha in average), mainly due to its abundance. Additionally, the family shows a noticeable habitat preference for certain soil conditions in the physiographic units, such is the case of Virola pavonis in "varillales", within "floodplain", or Iryanthera tessmannii and Virola loretensis in sewage flooded areas or "igapo" specifically, and the preference of Virola elongata and irola surinamensis for white water flooded areas or "varzea" edaphic conditions of the physiographic units taken in the study.

  4. The paradox of inverted biomass pyramids in kelp forest fish communities.

    PubMed

    Trebilco, Rowan; Dulvy, Nicholas K; Anderson, Sean C; Salomon, Anne K

    2016-06-29

    Theory predicts that bottom-heavy biomass pyramids or 'stacks' should predominate in real-world communities if trophic-level increases with body size (mean predator-to-prey mass ratio (PPMR) more than 1). However, recent research suggests that inverted biomass pyramids (IBPs) characterize relatively pristine reef fish communities. Here, we estimated the slope of a kelp forest fish community biomass spectrum from underwater visual surveys. The observed biomass spectrum slope is strongly positive, reflecting an IBP. This is incongruous with theory because this steep positive slope would only be expected if trophic position decreased with increasing body size (consumer-to-resource mass ratio, less than 1). We then used δ(15)N signatures of fish muscle tissue to quantify the relationship between trophic position and body size and instead detected strong evidence for the opposite, with PPMR ≈ 1650 (50% credible interval 280-12 000). The natural history of kelp forest reef fishes suggests that this paradox could arise from energetic subsidies in the form of movement of mobile consumers across habitats, and from seasonally pulsed production inputs at small body sizes. There were four to five times more biomass at large body sizes (1-2 kg) than would be expected in a closed steady-state community providing a measure of the magnitude of subsidies.

  5. Aboveground Biomass Monitoring over Siberian Boreal Forest Using Radar Remote Sensing Data

    NASA Astrophysics Data System (ADS)

    Stelmaszczuk-Gorska, M. A.; Thiel, C. J.; Schmullius, C.

    2014-12-01

    Aboveground biomass (AGB) plays an essential role in ecosystem research, global cycles, and is of vital importance in climate studies. AGB accumulated in the forests is of special monitoring interest as it contains the most of biomass comparing with other land biomes. The largest of the land biomes is boreal forest, which has a substantial carbon accumulation capability; carbon stock estimated to be 272 +/-23 Pg C (32%) [1]. Russian's forests are of particular concern, due to the largest source of uncertainty in global carbon stock calculations [1], and old inventory data that have not been updated in the last 25 years [2]. In this research new empirical models for AGB estimation are proposed. Using radar L-band data for AGB retrieval and optical data for an update of in situ data the processing scheme was developed. The approach was trained and validated in the Asian part of the boreal forest, in southern Russian Central Siberia; two Siberian Federal Districts: Krasnoyarsk Kray and Irkutsk Oblast. Together the training and testing forest territories cover an area of approximately 3,500 km2. ALOS PALSAR L-band single (HH - horizontal transmitted and received) and dual (HH and HV - horizontal transmitted, horizontal and vertical received) polarizations in Single Look Complex format (SLC) were used to calculate backscattering coefficient in gamma nought and coherence. In total more than 150 images acquired between 2006 and 2011 were available. The data were obtained through the ALOS Kyoto and Carbon Initiative Project (K&C). The data were used to calibrate a randomForest algorithm. Additionally, a simple linear and multiple-regression approach was used. The uncertainty of the AGB estimation at pixel and stand level were calculated approximately as 35% by validation against an independent dataset. The previous studies employing ALOS PALSAR data over boreal forests reported uncertainty of 39.4% using randomForest approach [2] or 42.8% using semi-empirical approach [3].

  6. Local spatial structure of forest biomass and its consequences for remote sensing of carbon stocks

    NASA Astrophysics Data System (ADS)

    Réjou-Méchain, M.; Muller-Landau, H. C.; Detto, M.; Thomas, S. C.; Le Toan, T.; Saatchi, S. S.; Barreto-Silva, J. S.; Bourg, N. A.; Bunyavejchewin, S.; Butt, N.; Brockelman, W. Y.; Cao, M.; Cárdenas, D.; Chiang, J.-M.; Chuyong, G. B.; Clay, K.; Condit, R.; Dattaraja, H. S.; Davies, S. J.; Duque, A.; Esufali, S.; Ewango, C.; Fernando, R. H. S.; Fletcher, C. D.; Gunatilleke, I. A. U. N.; Hao, Z.; Harms, K. E.; Hart, T. B.; Hérault, B.; Howe, R. W.; Hubbell, S. P.; Johnson, D. J.; Kenfack, D.; Larson, A. J.; Lin, L.; Lin, Y.; Lutz, J. A.; Makana, J.-R.; Malhi, Y.; Marthews, T. R.; McEwan, R. W.; McMahon, S. M.; McShea, W. J.; Muscarella, R.; Nathalang, A.; Noor, N. S. M.; Nytch, C. J.; Oliveira, A. A.; Phillips, R. P.; Pongpattananurak, N.; Punchi-Manage, R.; Salim, R.; Schurman, J.; Sukumar, R.; Suresh, H. S.; Suwanvecho, U.; Thomas, D. W.; Thompson, J.; Uríarte, M.; Valencia, R.; Vicentini, A.; Wolf, A. T.; Yap, S.; Yuan, Z.; Zartman, C. E.; Zimmerman, J. K.; Chave, J.

    2014-04-01

    Advances in forest carbon mapping have the potential to greatly reduce uncertainties in the global carbon budget and to facilitate effective emissions mitigation strategies such as REDD+. Though broad scale mapping is based primarily on remote sensing data, the accuracy of resulting forest carbon stock estimates depends critically on the quality of field measurements and calibration procedures. The mismatch in spatial scales between field inventory plots and larger pixels of current and planned remote sensing products for forest biomass mapping is of particular concern, as it has the potential to introduce errors, especially if forest biomass shows strong local spatial variation. Here, we used 30 large (8-50 ha) globally distributed permanent forest plots to quantify the spatial variability in aboveground biomass (AGB) at spatial grains ranging from 5 to 250 m (0.025-6.25 ha), and we evaluate the implications of this variability for calibrating remote sensing products using simulated remote sensing footprints. We found that the spatial sampling error in AGB is large for standard plot sizes, averaging 46.3% for 0.1 ha subplots and 16.6% for 1 ha subplots. Topographically heterogeneous sites showed positive spatial autocorrelation in AGB at scales of 100 m and above; at smaller scales, most study sites showed negative or nonexistent spatial autocorrelation in AGB. We further show that when field calibration plots are smaller than the remote sensing pixels, the high local spatial variability in AGB leads to a substantial "dilution" bias in calibration parameters, a bias that cannot be removed with current statistical methods. Overall, our results suggest that topography should be explicitly accounted for in future sampling strategies and that much care must be taken in designing calibration schemes if remote sensing of forest carbon is to achieve its promise.

  7. Quantifying the effect of forests on frequency and intensity of rockfalls

    NASA Astrophysics Data System (ADS)

    Moos, Christine; Dorren, Luuk; Stoffel, Markus

    2017-02-01

    Forests serve as a natural means of protection against small rockfalls. Due to their barrier effect, they reduce the intensity and the propagation probability of falling rocks and thus reduce the occurrence frequency of a rockfall event for a given element at risk. However, despite established knowledge on the protective effect of forests, they are generally neglected in quantitative rockfall risk analyses. Their inclusion in quantitative rockfall risk assessment would, however, be necessary to express their efficiency in monetary terms and to allow comparison of forests with other protective measures, such as nets and dams. The goal of this study is to quantify the effect of forests on the occurrence frequency and intensity of rockfalls. We therefore defined an onset frequency of blocks based on a power-law magnitude-frequency distribution and determined their propagation probabilities on a virtual slope based on rockfall simulations. Simulations were run for different forest and non-forest scenarios under varying forest stand and terrain conditions. We analysed rockfall frequencies and intensities at five different distances from the release area. Based on two multivariate statistical prediction models, we investigated which of the terrain and forest characteristics predominantly drive the role of forest in reducing rockfall occurrence frequency and intensity and whether they are able to predict the effect of forest on rockfall risk. The rockfall occurrence frequency below forested slopes is reduced between approximately 10 and 90 % compared to non-forested slope conditions; whereas rockfall intensity is reduced by 10 to 70 %. This reduction increases with increasing slope length and decreases with decreasing tree density, tree diameter and increasing rock volume, as well as in cases of clustered or gappy forest structures. The statistical prediction models reveal that the cumulative basal area of trees, block volume and horizontal forest structure represent key

  8. Validation of modelled forest biomass in Germany using BETHY/DLR

    NASA Astrophysics Data System (ADS)

    Tum, M.; Buchhorn, M.; Günther, K. P.; Haller, B. C.

    2011-07-01

    We present a new approach to the validation of modelled forest Net Primary Productivity (NPP), using empirical data on the mean annual increment, or MAI, in above-ground forest stock. The dynamic biomass model BETHY/DLR is used to estimate the NPP of forest areas in Germany, driven by remote sensing data from VEGETATION, meteorological data from the European Centre for Medium-Range Weather Forecasts (ECMWF), and additional tree coverage information from the MODIS Vegetation Continuous Field (VCF). The output of BETHY/DLR, Gross Primary Productivity (GPP), is converted to NPP by subtracting the cumulative plant maintenance and growth respiration, and then validated against MAI data derived from German forestry inventories. Validation is conducted for 2000 and 2001 by converting modelled NPP to stem volume at a regional level. Our analysis shows that the presented method fills an important gap in methods for validating modelled NPP against empirically derived data. In addition, we examine theoretical energy potentials calculated from the modelled and validated NPP, assuming sustainable forest management and using species-specific tree heating values. Such estimated forest biomass energy potentials play an important role in the sustainable energy debate.

  9. The linkages between photosynthesis, productivity, growth and biomass in lowland Amazonian forests.

    PubMed

    Malhi, Yadvinder; Doughty, Christopher E; Goldsmith, Gregory R; Metcalfe, Daniel B; Girardin, Cécile A J; Marthews, Toby R; Del Aguila-Pasquel, Jhon; Aragão, Luiz E O C; Araujo-Murakami, Alejandro; Brando, Paulo; da Costa, Antonio C L; Silva-Espejo, Javier E; Farfán Amézquita, Filio; Galbraith, David R; Quesada, Carlos A; Rocha, Wanderley; Salinas-Revilla, Norma; Silvério, Divino; Meir, Patrick; Phillips, Oliver L

    2015-06-01

    Understanding the relationship between photosynthesis, net primary productivity and growth in forest ecosystems is key to understanding how these ecosystems will respond to global anthropogenic change, yet the linkages among these components are rarely explored in detail. We provide the first comprehensive description of the productivity, respiration and carbon allocation of contrasting lowland Amazonian forests spanning gradients in seasonal water deficit and soil fertility. Using the largest data set assembled to date, ten sites in three countries all studied with a standardized methodology, we find that (i) gross primary productivity (GPP) has a simple relationship with seasonal water deficit, but that (ii) site-to-site variations in GPP have little power in explaining site-to-site spatial variations in net primary productivity (NPP) or growth because of concomitant changes in carbon use efficiency (CUE), and conversely, the woody growth rate of a tropical forest is a very poor proxy for its productivity. Moreover, (iii) spatial patterns of biomass are much more driven by patterns of residence times (i.e. tree mortality rates) than by spatial variation in productivity or tree growth. Current theory and models of tropical forest carbon cycling under projected scenarios of global atmospheric change can benefit from advancing beyond a focus on GPP. By improving our understanding of poorly understood processes such as CUE, NPP allocation and biomass turnover times, we can provide more complete and mechanistic approaches to linking climate and tropical forest carbon cycling.

  10. Reducing Uncertainties in Satellite-derived Forest Aboveground Biomass Estimates using a High Resolution Forest Cover Map

    NASA Astrophysics Data System (ADS)

    Zhang, G.; Ganguly, S.; Nemani, R. R.; Milesi, C.; Basu, S.; Kumar, U.

    2014-12-01

    Several studies to date have provided an extensive knowledge base for estimating forest aboveground biomass (AGB) and recent advances in space-based modeling of the 3-D canopy structure, combined with canopy reflectance measured by passive optical sensors and radar backscatter, are providing improved satellite-derived AGB density mapping for large scale carbon monitoring applications. A key limitation in forest AGB estimation from remote sensing, however, is the large uncertainty in forest cover estimates from the coarse-to-medium resolution satellite-derived land cover maps (present resolution is limited to 30-m of the USGS NLCD Program). The uncertainties in forest cover estimates at the Landsat scale result in high uncertainties for AGB estimation, predominantly in heterogeneous forest and urban landscapes. We have successfully developed an approach using a machine learning algorithm and High-Performance-Computing with NAIP air-borne imagery data for mapping tree cover at 1-m over California and Maryland. In a comparison with high resolution LiDAR data available over selected regions in the two states, we found our results to be promising both in terms of accuracy as well as our ability to scale nationally. The generated 1-m forest cover map will be aggregated to the Landsat spatial grid to demonstrate differences in AGB estimates (pixel-level AGB density, total AGB at aggregated scales like ecoregions and counties) when using a native 30-m forest cover map versus a 30-m map derived from a higher resolution dataset. The process will also be complemented with a LiDAR derived AGB estimate at the 30-m scale to aid in true validation.

  11. Carabid beetle diversity and mean individual biomass in beech forests of various ages

    PubMed Central

    Jelaska, Lucija Šerić; Dumbović, Vlatka; Kučinić, Mladen

    2011-01-01

    Abstract Carabid beetle diversity and mean individual biomass (MIB) were analysed in three different successional stages of beech tree stands (60, 80 and 150 years old). Carabid beetles were captured using pitfall traps placed at nine sites (three per age class) in the Papuk Mountain of East Croatia during 2008. A cluster analysis identified three groupings that corresponded to the beech age classes. MIB values increased with stand age, ranging from 255 in 60-year-old stand to 537 in the oldest forests. The 80-year-old stand showed the highest species richness and diversity values. With respect to species composition, large species such as Carabus scheidleri and Carabus coriaceus were dominant only in the oldest forests. Furthermore, species that overwinter in the larval stage were more abundant in the oldest forests (45% of the total number of individuals from the 150-year-old stand) than in the younger ones (20% of individuals from 60-year-old, and 22% of individuals from 80-year-old stands). Our results showed that the analyses of species composition and life history traits are valuable for estimating the conservation values of older forests. Although the investigated sites form part of a continuous forested area and are only a couple of kilometres apart, MIB values detect significant differences associated with forest age and can be a useful tool in evaluating the degree to which a forest reflects a natural state. PMID:21738423

  12. Carabid beetle diversity and mean individual biomass in beech forests of various ages.

    PubMed

    Jelaska, Lucija Šerić; Dumbović, Vlatka; Kučinić, Mladen

    2011-01-01

    Carabid beetle diversity and mean individual biomass (MIB) were analysed in three different successional stages of beech tree stands (60, 80 and 150 years old). Carabid beetles were captured using pitfall traps placed at nine sites (three per age class) in the Papuk Mountain of East Croatia during 2008. A cluster analysis identified three groupings that corresponded to the beech age classes. MIB values increased with stand age, ranging from 255 in 60-year-old stand to 537 in the oldest forests. The 80-year-old stand showed the highest species richness and diversity values. With respect to species composition, large species such as Carabus scheidleri and Carabus coriaceus were dominant only in the oldest forests. Furthermore, species that overwinter in the larval stage were more abundant in the oldest forests (45% of the total number of individuals from the 150-year-old stand) than in the younger ones (20% of individuals from 60-year-old, and 22% of individuals from 80-year-old stands). Our results showed that the analyses of species composition and life history traits are valuable for estimating the conservation values of older forests. Although the investigated sites form part of a continuous forested area and are only a couple of kilometres apart, MIB values detect significant differences associated with forest age and can be a useful tool in evaluating the degree to which a forest reflects a natural state.

  13. Aboveground Biomass Modeling from Field and LiDAR Data in Brazilian Amazon Tropical Rain Forest

    NASA Astrophysics Data System (ADS)

    Silva, C. A.; Hudak, A. T.; Vierling, L. A.; Keller, M. M.; Klauberg Silva, C. K.

    2015-12-01

    Tropical forests are an important component of global carbon stocks, but tropical forest responses to climate change are not sufficiently studied or understood. Among remote sensing technologies, airborne LiDAR (Light Detection and Ranging) may be best suited for quantifying tropical forest carbon stocks. Our objective was to estimate aboveground biomass (AGB) using airborne LiDAR and field plot data in Brazilian tropical rain forest. Forest attributes such as tree density, diameter at breast height, and heights were measured at a combination of square plots and linear transects (n=82) distributed across six different geographic zones in the Amazon. Using previously published allometric equations, tree AGB was computed and then summed to calculate total AGB at each sample plot. LiDAR-derived canopy structure metrics were also computed at each sample plot, and random forest regression modelling was applied to predict AGB from selected LiDAR metrics. The LiDAR-derived AGB model was assessed using the random forest explained variation, adjusted coefficient of determination (Adj. R²), root mean square error (RMSE, both absolute and relative) and BIAS (both absolute and relative). Our findings showed that the 99th percentile of height and height skewness were the best LiDAR metrics for AGB prediction. The AGB model using these two best predictors explained 59.59% of AGB variation, with an Adj. R² of 0.92, RMSE of 33.37 Mg/ha (20.28%), and bias of -0.69 (-0.42%). This study showed that LiDAR canopy structure metrics can be used to predict AGC stocks in Tropical Forest with acceptable precision and accuracy. Therefore, we conclude that there is good potential to monitor carbon sequestration in Brazilian Tropical Rain Forest using airborne LiDAR data, large field plots, and the random forest algorithm.

  14. Soil humus composition - comparison between mountain grasslands and forest lands with different land-use intensity

    NASA Astrophysics Data System (ADS)

    Naydenova, Lora; Zhiyanski, Miglena; Leifeld, Jens; Filcheva, Ekaterina

    2015-04-01

    Soil humus is a dynamic characteristic greatly vulnerable to land use and climate and with important feedbacks to the atmospheric green house gas balance and the rate of climate change. The increased demand for accurate soil carbon stocks assessments and predictions of its changes as a result of land use/cover and climate change has triggered large-scale and long-term measurements of soil organic matter specifics. We studied the soil humus composition in four mountain grasslands, differentiated according to the land-use sub-type and land-use intensity and four forest lands. Two pastures - with intensive (Pi) and extensive grazing (Pe) and two meadows- managed (Mm) and unmanaged (Mu) were objects of present study. Two spruce plantations (Picea abies Karst), and two natural beech forests (Fagus sylvatica L.) - control, unmanaged for the both (Su and Bu) and with 10 % cutting intensity (Sc and Bc). Humus composition was analyzed following the methodology of Kononova-Belchikova. The aggressive and mobile fulvic acids predominated in all of the investigated plots, except Pe and Bu. Humic acids are "free" and bonded with R3O3 and no Ca-bonded humic acids were established under the grasslands, but in the soils under the two beech forest we observed Ca-bonded humic acids in small quantities. The values of total org. C and C-extracted by 0.1 N NaOH was similar in most of studied horizons. Our results showed that the highest total carbon content was localized in the organic-mineral soil horizon and decreased toward deeper soil. The highest total carbon content estimated at 14.04 % was determined in A-horizon of soil in pasture with extensive grazing, for the grasslands. The higher grazing disturbance in Pi leads to increase root biomass in patch areas and in inter-patch upper soil related with decrease of soil humus content. We supposed that the reduced amount of litter input with increased recalcitrance to decomposition provoked the reduction of organic carbon content and

  15. Developing synergy regression models with space-borne ALOS PALSAR and Landsat TM sensors for retrieving tropical forest biomass

    NASA Astrophysics Data System (ADS)

    Sinha, Suman; Jeganathan, C.; Sharma, L. K.; Nathawat, M. S.; Das, Anup K.; Mohan, Shiv

    2016-06-01

    Forest stand biomass serves as an effective indicator for monitoring REDD (reducing emissions from deforestation and forest degradation). Optical remote sensing data have been widely used to derive forest biophysical parameters inspite of their poor sensitivity towards the forest properties. Microwave remote sensing provides a better alternative owing to its inherent ability to penetrate the forest vegetation. This study aims at developing optimal regression models for retrieving forest above-ground bole biomass (AGBB) utilising optical data from Landsat TM and microwave data from L-band of ALOS PALSAR data over Indian subcontinental tropical deciduous mixed forests located in Munger (Bihar, India). Spatial biomass models were developed. The results using Landsat TM showed poor correlation ( R 2 = 0.295 and RMSE = 35 t/ha) when compared to HH polarized L-band SAR ( R 2 = 0.868 and RMSE = 16.06 t/ha). However, the prediction model performed even better when both the optical and SAR were used simultaneously ( R 2 = 0.892 and RMSE = 14.08 t/ha). The addition of TM metrics has positively contributed in improving PALSAR estimates of forest biomass. Hence, the study recommends the combined use of both optical and SAR sensors for better assessment of stand biomass with significant contribution towards operational forestry.

  16. Linking the fPAR, forest albedo and biomass in the northern biomes of Europe

    NASA Astrophysics Data System (ADS)

    Lukeš, Petr; Stenberg, Pauline; Manninen, Terhikki; Rautiainen, Miina; Mõttus, Matti

    2014-05-01

    Land surface albedo and the fraction of photosynthetically active radiation (fPAR) absorbed by plant canopies are two of the essential climate variables controlling the planetary radiative energy budget. Albedo is directly related to the energy exchange between land and the atmosphere as it is the reflectivity of the surface - the higher the albedo, the more incoming solar radiation is reflected and the less absorbed by the surface. The fPAR is related to plant productivity, quantifying the amount of absorbed light available for photosynthesis. It is a key parameter in the modelling of net primary production (NPP) of terrestrial ecosystems. Global climate scenarios are very sensitive to albedo and fPAR estimates, and thus, the effect of changes in canopy structure and density (biomass) on these two variables needs to be quantified reliably. Both parameters are routinely retrieved from current Earth Observation sensors using specialized algorithms. To date, these satellite products have not been linked to extensive forest inventory data sets due to the lack of ground reference data. Data availability for Finland has significantly improved in December 2012, when National Forest Inventory (NFI) data became freely available to the public. The dataset covers the geographical area of Finland (26.1 million hectares) at a spatial resolution of 20 meters including several forest structural variables. In this study, we use the NFI data to study the links between forest albedo, fPAR and forest structure and density during the green vegetation season. More specifically, we investigated the seasonal trends in fPAR and albedo of different spectral regions of northern forests. Empirical relationships between forest albedo, fPAR and total aboveground biomass were established for selected days within the vegetation growing period and across a latitudinal transect of Finland.

  17. The contribution of trees outside forests to national tree biomass and carbon stocks--a comparative study across three continents.

    PubMed

    Schnell, Sebastian; Altrell, Dan; Ståhl, Göran; Kleinn, Christoph

    2015-01-01

    In contrast to forest trees, trees outside forests (TOF) often are not included in the national monitoring of tree resources. Consequently, data about this particular resource is rare, and available information is typically fragmented across the different institutions and stakeholders that deal with one or more of the various TOF types. Thus, even if information is available, it is difficult to aggregate data into overall national statistics. However, the National Forest Monitoring and Assessment (NFMA) programme of FAO offers a unique possibility to study TOF resources because TOF are integrated by default into the NFMA inventory design. We have analysed NFMA data from 11 countries across three continents. For six countries, we found that more than 10% of the national above-ground tree biomass was actually accumulated outside forests. The highest value (73%) was observed for Bangladesh (total forest cover 8.1%, average biomass per hectare in forest 33.4 t ha(-1)) and the lowest (3%) was observed for Zambia (total forest cover 63.9%, average biomass per hectare in forest 32 t ha(-1)). Average TOF biomass stocks were estimated to be smaller than 10 t ha(-1). However, given the large extent of non-forest areas, these stocks sum up to considerable quantities in many countries. There are good reasons to overcome sectoral boundaries and to extend national forest monitoring programmes on a more systematic basis that includes TOF. Such an approach, for example, would generate a more complete picture of the national tree biomass. In the context of climate change mitigation and adaptation, international climate mitigation programmes (e.g. Clean Development Mechanism and Reduced Emission from Deforestation and Degradation) focus on forest trees without considering the impact of TOF, a consideration this study finds crucial if accurate measurements of national tree biomass and carbon pools are required.

  18. Biomass and nutrient dynamics associated with slash fires in neotropical dry forests

    SciTech Connect

    Kauffman, J.B.; Cummings, D.L. ); Sanford, R.L. Jr. ); Salcedo, I.H.; Sampaio, E.V.S.B. )

    1993-01-01

    Unprecedented rates of deforestation and biomass burning in tropical dry forests are dramatically influencing biogeochemical cycles, resulting in resource depletion, declines in biodiversity, and atmospheric pollution. We quantified the effects of deforestation and varying levels of slash-fire severity on nutrient losses and redistribution in a second-growth tropical dry forest ([open quotes]Caatinga[close quotes]) near Serra Talhada, Pernambuco, Brazil. Total aboveground biomass prior to burning was [approx]74 Mg/ha. Nitrogen and phosphorus concentrations were highest in litter, leaves attached to slash, and fine wood debris (biomass, they accounted for [approx]60% of the aboveground pools of N and P. Three experimental fires were conducted during the 1989 burning season. Consumption was 78, 88, and 95% of the total aboveground biomass. As much as 96% of the prefire aboveground N and C pools and 56% of the prefire aboveground P pool was lost. Nitrogen losses exceeded 500 kg/ha and P losses exceeded 20 kg/ha in the fires of the greatest severity. With increasing fire severity, the concentrations of N and P in ash decreased while the concentration of Ca increased. Greater ecosystem losses of these nutrients occurred with increasing fire severity. Following fire, up to 47% of the residual aboveground N and 84% of the residual aboveground P were in the form of ash, quickly lost from the site via wind erosion. Fires appeared to have a minor immediate effect on total N, C, or P in the soils. However, soils in forests with no history of cultivation had significantly higher concentrations of C and P than second-growth forests. It would likely require a century or more of fallow for reaccumulation to occur. However, current fallow periods in this region are 15 yr or less. 38 refs., 2 figs., 7 tabs.

  19. Forest biomass flow for fuel wood, fodder and timber security among tribal communities of Jharkhand.

    PubMed

    Islam, M A; Quli, S M S; Rai, R; Ali, Angrej; Gangoo, S A

    2015-01-01

    The study investigated extraction and consumption pattern of fuel wood, fodder and timber and forest biomass flow for fuel wood, fodder and timber security among tribal communities in Bundu block of Ranchi district in Jharkhand (India). The study is based on personal interviews of the selected respondents through structured interview schedule, personal observations and participatory rural appraisal tools i.e. key informant interviews and focus group discussions carried out in the sample villages, using multi-stage random sampling technique. The study revealed that the total extraction of fuel wood from different sources in villages was 2978.40 tons annum(-1), at the rate of 0.68 tons per capita annum(-1), which was mostly consumed in cooking followed by cottage industries, heating, community functions and others. The average fodder requirement per household was around 47.77 kg day(-1) with a total requirement of 14227.34 tons annum(-1). The average timber requirement per household was computed to be 0.346 m3 annum(-1) accounting for a total timber demand of 282.49 m3 annum(-1), which is mostly utilized in housing, followed by agricultural implements, rural furniture, carts and carriages, fencing, cattle shed/ store house and others. Forest biomass is the major source of fuel wood, fodder and timber for the primitive societies of the area contributing 1533.28 tons annum(-1) (51.48%) of the total fuel wood requirement, 6971.55 tons annum(-1) (49.00%) of the total fodder requirement and 136.36 m3 annum(-1) (48.27%) of the total timber requirement. The forest biomass is exposed to enormous pressure for securing the needs by the aboriginal people, posing great threat to biodiversity and environment of the region. Therefore, forest biomass conservation through intervention of alternative avenues is imperative to keep pace with the current development and future challenges in the area.

  20. Spatio-temporal modelling of biomass of intensively grazed perennial dairy pastures using multispectral remote sensing

    NASA Astrophysics Data System (ADS)

    Edirisinghe, Asoka; Clark, Dave; Waugh, Deanne

    2012-06-01

    Pasture biomass is a vital input for management of dairy systems in New Zealand. An accurate estimate of pasture biomass information is required for the calculation of feed budget, on which decisions are made for farm practices such as conservation, nitrogen use, rotational lengths and supplementary feeding leading to profitability and sustainable use of pasture resources. The traditional field based methods of measuring pasture biomass such as using rising plate metres (RPM) are largely inefficient in providing the timely information at the spatial extent and temporal frequency demanded by commercial environments. In recent times remote sensing has emerged as an alternative tool. In this paper we have examined the Normalised Difference Vegetation Index (NDVI) derived from medium resolution imagery of SPOT-4 and SPOT-5 satellite sensors to predict pasture biomass of intensively grazed dairy pastures. In the space and time domain analysis we have found a significant dependency of time over the season and no dependency of space across the scene at a given time for the relationship between NDVI and field based pasture biomass. We have established a positive correlation (81%) between the two variables in a pixel scale analysis. The application of the model on 2 selected farms over 3 images and aggregation of the predicted biomass to paddock scale has produced paddock average pasture biomass values with a coefficient of determination of 0.71 and a standard error of 260 kg DM ha-1 in the field observed range between 1500 and 3500 kg DM ha-1. This result indicates a high potential for operational use of remotely sensed data to predict pasture biomass of intensively grazed dairy pastures.

  1. Exploring the Natural Fungal Biodiversity of Tropical and Temperate Forests toward Improvement of Biomass Conversion

    PubMed Central

    Navarro, David; Couturier, Marie; Olivé, Caroline; Grisel, Sacha; Haon, Mireille; Taussac, Sabine; Lechat, Christian; Courtecuisse, Régis; Favel, Anne; Coutinho, Pedro M.; Lesage-Meessen, Laurence

    2012-01-01

    In this study, natural fungal diversity in wood-decaying species was explored for biomass deconstruction. In 2007 and 2008, fungal isolates were collected in temperate forests mainly from metropolitan France and in tropical forests mainly from French Guiana. We recovered and identified 74 monomorph cultures using morphological and molecular identification tools. Following production of fungal secretomes under inductive conditions, we evaluated the capacity of these fungal strains to potentiate a commercial Trichoderma reesei cellulase cocktail for the release of soluble sugars from biomass. The secretome of 19 isolates led to an improvement in biomass conversion of at least 23%. Of the isolates, the Trametes gibbosa BRFM 952 (Banque de Ressources Fongiques de Marseille) secretome performed best, with 60% improved conversion, a feature that was not universal to the Trametes and related genera. Enzymatic characterization of the T. gibbosa BRFM 952 secretome revealed an unexpected high activity on crystalline cellulose, higher than that of the T. reesei cellulase cocktail. This report highlights the interest in a systematic high-throughput assessment of collected fungal biodiversity to improve the enzymatic conversion of lignocellulosic biomass. It enabled the unbiased identification of new fungal strains issued from biodiversity with high biotechnological potential. PMID:22773628

  2. Exploring the natural fungal biodiversity of tropical and temperate forests toward improvement of biomass conversion.

    PubMed

    Berrin, Jean-Guy; Navarro, David; Couturier, Marie; Olivé, Caroline; Grisel, Sacha; Haon, Mireille; Taussac, Sabine; Lechat, Christian; Courtecuisse, Régis; Favel, Anne; Coutinho, Pedro M; Lesage-Meessen, Laurence

    2012-09-01

    In this study, natural fungal diversity in wood-decaying species was explored for biomass deconstruction. In 2007 and 2008, fungal isolates were collected in temperate forests mainly from metropolitan France and in tropical forests mainly from French Guiana. We recovered and identified 74 monomorph cultures using morphological and molecular identification tools. Following production of fungal secretomes under inductive conditions, we evaluated the capacity of these fungal strains to potentiate a commercial Trichoderma reesei cellulase cocktail for the release of soluble sugars from biomass. The secretome of 19 isolates led to an improvement in biomass conversion of at least 23%. Of the isolates, the Trametes gibbosa BRFM 952 (Banque de Ressources Fongiques de Marseille) secretome performed best, with 60% improved conversion, a feature that was not universal to the Trametes and related genera. Enzymatic characterization of the T. gibbosa BRFM 952 secretome revealed an unexpected high activity on crystalline cellulose, higher than that of the T. reesei cellulase cocktail. This report highlights the interest in a systematic high-throughput assessment of collected fungal biodiversity to improve the enzymatic conversion of lignocellulosic biomass. It enabled the unbiased identification of new fungal strains issued from biodiversity with high biotechnological potential.

  3. Modeling forest biomass of the Congo basin from extensive commercial inventories

    NASA Astrophysics Data System (ADS)

    Molto, Quentin; Réjou-Méchain, Maxime; Bayol, Nicolas; Chevalier, Jean-François; Rossi, Vivien; Cornu, Guillaume; Benedet, Fabrice; Gond, Valery; Gourlet-Fleury, Sylvie

    2015-04-01

    Mapping the vegetation Carbon stocks is crucial to understand the global climate change. The Carbon stock maps have direct implications in economy and environmental policy. This is especially true in tropical forests where most of the uncertainties on carbon fluxes and stocks are concentrated. Substantial efforts have been done recently to map forest carbon in tropical areas, especially by using remote sensing-based approaches. However, there is no way to bypass a calibration step where biomass is locally measured through forest inventories. The great importance of this learning step and its possible issues has been documented, highlighting the importance of terrestrial datasets. In our work, we have gathered a very large dataset of forest inventories covering the Congo Basin. It consists of 73 000 0.5ha plots of commercial inventories covering 4 million hectares in Cameroon, Republic of Congo, Gabon, Central African Republic, and the Democratic Republic of the Congo. These terrestrial data are of great value to understand and model the spatial distribution of various forest properties, among which the Carbon stock. They can also make a great tool to control and improve the performance of the remote sensing methods. In our study, we rely on these plots to test the validity of previously published pantropical Carbon maps. After gathering the data with extra care due to the heterogeneous inventory methods, we used bioclimatic models, topography, and remote sensing observation to extrapolate the forest carbon estimates at the Congo basin scale.

  4. Pattern and dynamics of biomass stock in old growth forests: The role of habitat and tree size

    NASA Astrophysics Data System (ADS)

    Yuan, Zuoqiang; Gazol, Antonio; Wang, Xugao; Lin, Fei; Ye, Ji; Zhang, Zhaochen; Suo, YanYan; Kuang, Xu; Wang, Yunyun; Jia, Shihong; Hao, Zhanqing

    2016-08-01

    Forest ecosystems play a fundamental role in the global carbon cycle. However, how stand-level changes in tree age and structure influence biomass stock and dynamics in old-growth forests is a question that remains unclear. In this study, we quantified the aboveground biomass (AGB) standing stock, the coarse woody productivity (CWP), and the change in biomass over ten years (2004-2014) in a 25 ha unmanaged broad-leaved Korean pine mixed forest in northeastern China. In addition, we quantified how AGB stock and change (tree growth, recruitment and mortality) estimations are influenced by the variation in habitat heterogeneity, tree size structure and subplot size. Our analysis indicated that Changbai forest had AGB of 265.4 Mg ha-1 in 2004, and gained1.36 Mg ha-1 y-1 between 2004 and 2014. Despite recruitment having better performance in nutrient rich habitat, we found that there is a directional tree growth trend independent of habitat heterogeneity for available nutrients in this old growth forest. The observed increases in AGB stock (∼70%) are mainly attributed to the growth of intermediate size trees (30-70 cm DBH), indicating that this forest is still reaching its mature stage. Meanwhile, we indicated that biomass loss due to mortality reduces living biomass, not increment, may be the primary factor to affect forest biomass dynamics in this area. Also, spatial variation in forest dynamics is large for small sizes (i.e. coefficient of variation in 20 × 20 m subplots is 53.2%), and more than 90 percent of the inherent variability of these coefficients was predicted by a simple model including plot size. Our result provides a mean by which to estimate within-plot variability at a local scale before inferring any directional change in forest dynamics at a regional scale, and information about the variability of forest structure and dynamics are fundamental to design effective sampling strategies in future study.

  5. Countrywide Forest Biomass Estimates from PALSAR L-Band Backscatter to Improve Greenhouse Gas Inventory in Estonia

    NASA Astrophysics Data System (ADS)

    Olesk, A.; Voormansik, K.; Luud, Aarne; Renne, M.; Zalite, K.; Noorma, M.; Reinart, A.

    2013-08-01

    Accurately estimated forest biomass and its distribution is a key parameter for forest inventories, vegetation modeling and understanding the global carbon cycle. It is also required by the United Nations and Intergovernmental Panel on Climate Change (IPCC) to provide a comprehensive analysis on estimates of terrestrial carbon fluxes for climate change reports. To improve the understanding of the carbon balance in Estonia, where forests cover over half of the land, a methodology has been worked out to map the changes in the forest biomass in yearly basis using satellite and forest inventory data. To assess the above-ground biomass in temperate deciduous, coniferous and mixed forest of Estonia, measurements and imagery from dual polarimetric L-band SAR (Synthetic Aperature Radar) and optical remote sensing satellites were used. A country-specific model allows easily regenerating the forest biomass estimations with the newest satellite data and producing up-to-date biomass maps that can be used to assist the national inventory reporting under the Intergovernmental Negotiating Committee for a Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol.

  6. The Price of Precision: Large-Scale Mapping of Forest Structure and Biomass Using Airborne Lidar

    NASA Astrophysics Data System (ADS)

    Dubayah, R.

    2015-12-01

    Lidar remote sensing provides one of the best means for acquiring detailed information on forest structure. However, its application over large areas has been limited largely because of its expense. Nonetheless, extant data exist over many states in the U.S., funded largely by state and federal consortia and mainly for infrastructure, emergency response, flood plain and coastal mapping. These lidar data are almost always acquired in leaf-off seasons, and until recently, usually with low point count densities. Even with these limitations, they provide unprecedented wall-to-wall mappings that enable development of appropriate methodologies for large-scale deployment of lidar. In this talk we summarize our research and lessons learned in deriving forest structure over regional areas as part of NASA's Carbon Monitoring System (CMS). We focus on two areas: the entire state of Maryland and Sonoma County, California. The Maryland effort used low density, leaf-off data acquired by each county in varying epochs, while the on-going Sonoma work employs state-of-the-art, high density, wall-to-wall, leaf-on lidar data. In each area we combine these lidar coverages with high-resolution multispectral imagery from the National Agricultural Imagery Program (NAIP) and in situ plot data to produce maps of canopy height, tree cover and biomass, and compare our results against FIA plot data and national biomass maps. Our work demonstrates that large-scale mapping of forest structure at high spatial resolution is achievable but products may be complex to produce and validate over large areas. Furthermore, fundamental issues involving statistical approaches, plot types and sizes, geolocation, modeling scales, allometry, and even the definitions of "forest" and "non-forest" must be approached carefully. Ultimately, determining the "price of precision", that is, does the value of wall-to-wall forest structure data justify their expense, should consider not only carbon market applications

  7. Effects of LiDAR point density and landscape context on the retrieval of urban forest biomass

    NASA Astrophysics Data System (ADS)

    Singh, K. K.; Chen, G.; McCarter, J. B.; Meentemeyer, R. K.

    2014-12-01

    Light Detection and Ranging (LiDAR), as an alternative to conventional optical remote sensing, is being increasingly used to accurately estimate aboveground forest biomass ranging from individual tree to stand levels. Recent advancements in LiDAR technology have resulted in higher point densities and better data accuracies, which however pose challenges to the procurement and processing of LiDAR data for large-area assessments. Reducing point density cuts data acquisition costs and overcome computational challenges for broad-scale forest management. However, how does that impact the accuracy of biomass estimation in an urban environment containing a great level of anthropogenic disturbances? The main goal of this study is to evaluate the effects of LiDAR point density on the biomass estimation of remnant forests in the rapidly urbanizing regions of Charlotte, North Carolina, USA. We used multiple linear regression to establish the statistical relationship between field-measured biomass and predictor variables (PVs) derived from LiDAR point clouds with varying densities. We compared the estimation accuracies between the general Urban Forest models (no discrimination of forest type) and the Forest Type models (evergreen, deciduous, and mixed), which was followed by quantifying the degree to which landscape context influenced biomass estimation. The explained biomass variance of Urban Forest models, adjusted R2, was fairly consistent across the reduced point densities with the highest difference of 11.5% between the 100% and 1% point densities. The combined estimates of Forest Type biomass models outperformed the Urban Forest models using two representative point densities (100% and 40%). The Urban Forest biomass model with development density of 125 m radius produced the highest adjusted R2 (0.83 and 0.82 at 100% and 40% LiDAR point densities, respectively) and the lowest RMSE values, signifying the distance impact of development on biomass estimation. Our evaluation

  8. Assessing Extension's Ability to Promote Family Forests as a Woody Biomass Feedstock in the Northeast United States

    ERIC Educational Resources Information Center

    Germain, Rene' H.; Ghosh, Chandrani

    2013-01-01

    The study reported here surveyed Extension educators' awareness and knowledge of woody biomass energy and assessed their desire and ability to reach out to family forest owners-a critical feedstock source. The results indicate Extension educators are aware of the potential of woody biomass to serve as a renewable source of energy. Respondents…

  9. The influence of land use and climate change on forest biomass and composition in Massachusetts, USA.

    PubMed

    Thompson, Jonathan R; Foster, David R; Scheller, Robert; Kittredge, David

    2011-10-01

    Land use and climate change have complex and interacting effects on naturally dynamic forest landscapes. To anticipate and adapt to these changes, it is necessary to understand their individual and aggregate impacts on forest growth and composition. We conducted a simulation experiment to evaluate regional forest change in Massachusetts, USA over the next 50 years (2010-2060). Our objective was to estimate, assuming a linear continuation of recent trends, the relative and interactive influence of continued growth and succession, climate change, forest conversion to developed uses, and timber harvest on live aboveground biomass (AGB) and tree species composition. We examined 20 years of land use records in relation to social and biophysical explanatory variables and used regression trees to create "probability-of-conversion" and "probability-of-harvest" zones. We incorporated this information into a spatially interactive forest landscape simulator to examine forest dynamics as they were affected by land use and climate change. We conducted simulations in a full-factorial design and found that continued forest growth and succession had the largest effect on AGB, increasing stores from 181.83 Tg to 309.56 Tg over 50 years. The increase varied from 49% to 112% depending on the ecoregion within the state. Compared to simulations with no climate or land use, forest conversion reduced gains in AGB by 23.18 Tg (or 18%) over 50 years. Timber harvests reduced gains in AGB by 5.23 Tg (4%). Climate change (temperature and precipitation) increased gains in AGB by 17.3 Tg (13.5%). Pinus strobus and Acer rubrum were ranked first and second, respectively, in terms of total AGB throughout all simulations. Climate change reinforced the dominance of those two species. Timber harvest reduced Quercus rubra from 10.8% to 9.4% of total AGB, but otherwise had little effect on composition. Forest conversion was generally indiscriminate in terms of species removal. Under the naive

  10. Empirical Relationship Between Leaf Biomass of Red Pine Forests and Enhanced Vegetation Index in South Korea Using LANDSAT-5 TM

    NASA Astrophysics Data System (ADS)

    Gusso, A.; Lee, J.; Son, Y.; Son, Y. M.

    2016-06-01

    Research on forest carbon (C) dynamics has been undertaken due to the importance of forest ecosystems in national C inventories. Currently, the C sequestration of South Korean forests surpasses that of other countries. In South Korea, Pinus densiflora (red pine) is the most abundant tree species. Thus, understanding the growth rate and biomass evolution of red pine forest in South Korea is important for estimating the forest C dynamics. In this paper, we derived empirical relationship between foliage biomass and the no blue band enhanced vegetation index (EVI-2) profile using both field work and multi-temporal Landsat-5 TM remote sensing data to estimate the productivity of forest biomass in South Korea. Our analysis combined a set of 84 Landsat-5 TM images from 28 different dates between 1986 and 2008 to study red pine forest development over time. Field data were collected from 30 plots (0.04 ha) that were irregularly distributed over South Korea. Individual trees were harvested by destructive sampling, and the age of trees were determined by the number of tree rings. The results are realistic (R2&thinsp=&thinsp0.81, p < 0.01) and suggest that the EVI-2 index is able to adequately represent the development profile of foliage biomass in red pine forest growth.

  11. Optimal Wavelength Selection on Hyperspectral Data with Fused Lasso for Biomass Estimation of Tropical Rain Forest

    NASA Astrophysics Data System (ADS)

    Takayama, T.; Iwasaki, A.

    2016-06-01

    Above-ground biomass prediction of tropical rain forest using remote sensing data is of paramount importance to continuous large-area forest monitoring. Hyperspectral data can provide rich spectral information for the biomass prediction; however, the prediction accuracy is affected by a small-sample-size problem, which widely exists as overfitting in using high dimensional data where the number of training samples is smaller than the dimensionality of the samples due to limitation of require time, cost, and human resources for field surveys. A common approach to addressing this problem is reducing the dimensionality of dataset. Also, acquired hyperspectral data usually have low signal-to-noise ratio due to a narrow bandwidth and local or global shifts of peaks due to instrumental instability or small differences in considering practical measurement conditions. In this work, we propose a methodology based on fused lasso regression that select optimal bands for the biomass prediction model with encouraging sparsity and grouping, which solves the small-sample-size problem by the dimensionality reduction from the sparsity and the noise and peak shift problem by the grouping. The prediction model provided higher accuracy with root-mean-square error (RMSE) of 66.16 t/ha in the cross-validation than other methods; multiple linear analysis, partial least squares regression, and lasso regression. Furthermore, fusion of spectral and spatial information derived from texture index increased the prediction accuracy with RMSE of 62.62 t/ha. This analysis proves efficiency of fused lasso and image texture in biomass estimation of tropical forests.

  12. 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.

  13. Stability, Bistability, and Critical Thresholds in Fire-prone Forested Landscapes: How Frequency and Intensity of Disturbance Interact and Influence Forest Cover

    NASA Astrophysics Data System (ADS)

    Miller, A. D.

    2015-12-01

    Many aspects of disturbance processes can have large impacts on the composition of plant communities, and associated changes in land cover type in turn have biogeochemical feedbacks to climate. In particular, changes to disturbance regimes can potentially change the number and stability of equilibrial states, and plant community states can differ dramatically in their carbon (C) dynamics, energy balance, and hydrology. Using the Klamath region of northern California as a model system, we present a theoretical analysis of how changes to climate and associated fire dynamics can disrupt high-carbon, long-lived conifer forests and replace them with shrub-chaparral communities that have much lower biomass and are more pyrogenic. Specifically, we develop a tractable model of plant community dynamics, structured by size class, life-history traits, lottery-type competition, and species-specific responses to disturbance. We assess the stability of different states in terms of disturbance frequency and intensity, and quantitatively partition long-term low-density population growth rates into mechanisms that influence critical transitions from stable to bistable behavior. Our findings show how different aspects of disturbance act and interact to control competitive outcomes and stable states, hence ecosystem-atmosphere C exchange. Forests tend to dominate in low frequency and intensity regimes, while shrubs dominate at high fire frequency and intensity. In other regimes, the system is bistable, and the fate of the system depends both on initial conditions and random chance. Importantly, the system can cross a critical threshold where hysteresis prevents easy return to the prior forested state. We conclude that changes in disturbance-recovery dynamics driven by projected climate change can shift this system away from forest dominated in the direction of shrub-dominated landscape. This will result in a large net C release from the landscape, and alter biophysical ecosystem

  14. Estimation of tropical forest height and biomass dynamics using lidar remote sensing at La Selva, Costa Rica

    NASA Astrophysics Data System (ADS)

    Dubayah, R. O.; Sheldon, S. L.; Clark, D. B.; Hofton, M. A.; Blair, J. B.; Hurtt, G. C.; Chazdon, R. L.

    2010-06-01

    In this paper we present the results of an experiment to measure forest structure and biomass dynamics over the tropical forests of La Selva Biological Station in Costa Rica using a medium resolution lidar. Our main objective was to observe changes in forest canopy height, related height metrics, and biomass, and from these map sources and sinks of carbon across the landscape. The Laser Vegetation Imaging Sensor (LVIS) measured canopy structure over La Selva in 1998 and again in 2005. Changes in waveform metrics were related to field-derived changes in estimated aboveground biomass from a series of old growth and secondary forest plots. Pairwise comparisons of nearly coincident lidar footprints between years showed canopy top height changes that coincided with expected changes based on land cover types. Old growth forests had a net loss in height of -0.33 m, while secondary forests had net gain of 2.08 m. Multiple linear regression was used to relate lidar metrics with biomass changes for combined old growth and secondary forest plots, giving an r2 of 0.65 and an RSE of 10.5 Mg/ha, but both parametric and bootstrapped confidence intervals were wide, suggesting weaker model performance. The plot level relationships were then used to map biomass changes across La Selva using LVIS at a 1 ha scale. The spatial patterns of biomass changes matched expected patterns given the distribution of land cover types at La Selva, with secondary forests showing a gain of 25 Mg/ha and old growth forests showing little change (2 Mg/ha). Prediction intervals were calculated to assess uncertainty for each 1 ha cell to ascertain whether the data and methods used could confidently estimate the sign (source or sink) of the biomass changes. The resulting map showed most of the old growth areas as neutral (no net biomass change), with widely scattered and isolated sources and sinks. Secondary forests in contrast were mostly sinks or neutral, but were never sources. By quantifying both the

  15. Properties and evolution of biomass burning organic aerosol from Canadian boreal forest fires

    NASA Astrophysics Data System (ADS)

    Jolleys, M. D.; Coe, H.; McFiggans, G.; Taylor, J. W.; O'Shea, S. J.; Le Breton, M.; Bauguitte, S. J.-B.; Moller, S.; Di Carlo, P.; Aruffo, E.; Palmer, P. I.; Lee, J. D.; Percival, C. J.; Gallagher, M. W.

    2015-03-01

    Airborne measurements of biomass burning organic aerosol (BBOA) from boreal forest fires reveal highly contrasting properties for plumes of different ages. These measurements, performed using an Aerodyne Research Inc. compact time-of-flight aerosol mass spectrometer (C-ToF-AMS) during the BORTAS (quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites) experiment in the summer of 2011, have been used to derive normalised excess organic aerosol (OA) mass concentrations (ΔOA / ΔCO), with higher average ratios observed closer to source (0.190±0.010) than in the far-field (0.097±0.002). The difference in ΔOA / ΔCO between fresh and aged plumes is influenced by a change in dominant combustion conditions throughout the campaign. Measurements at source comprised 3 plume interceptions during a single research flight and sampled largely smouldering fires. Twenty-three interceptions were made across four flights in the far-field, with plumes originating from fires occurring earlier in the campaign when fire activity had been more intense, creating an underlying contrast in emissions prior to any transformations associated with aging. Changing combustion conditions also affect the vertical distribution of biomass burning emissions, as aged plumes from more flaming-dominated fires are injected to higher altitudes of up to 6000 m. Proportional contributions of the mass-to-charge ratio (m/z) 60 and 44 peaks in the AMS mass spectra to the total OA mass (denoted f60 and f44) are used as tracers for primary and oxidised BBOA, respectively. f44 is lower on average in near-field plumes than those sampled in the far-field, in accordance with longer aging times as plumes are transported a greater distance from source. However, high levels of ΔO3 / ΔCO and -log(NOx / NOy) close to source indicate that emissions can be subject to very rapid oxidation over short timescales. Conversely, the lofting of plumes into the

  16. Radiative Effects of Aerosols Generated from Biomass Burning, Dust Storms, and Forest Fires

    NASA Technical Reports Server (NTRS)

    Christopher Sundar A.; Vulcan, Donna V.; Welch, Ronald M.

    1996-01-01

    Atmospheric aerosol particles, both natural and anthropogenic, are important to the earth's radiative balance. They scatter the incoming solar radiation and modify the shortwave reflective properties of clouds by acting as Cloud Condensation Nuclei (CCN). Although it has been recognized that aerosols exert a net cooling influence on climate (Twomey et al. 1984), this effect has received much less attention than the radiative forcings due to clouds and greenhouse gases. The radiative forcing due to aerosols is comparable in magnitude to current anthropogenic greenhouse gas forcing but opposite in sign (Houghton et al. 1990). Atmospheric aerosol particles generated from biomass burning, dust storms and forest fires are important regional climatic variables. A recent study by Penner et al. (1992) proposed that smoke particles from biomass burning may have a significant impact on the global radiation balance. They estimate that about 114 Tg of smoke is produced per year in the tropics through biomass burning. The direct and indirect effects of smoke aerosol due to biomass burning could add up globally to a cooling effect as large as 2 W/sq m. Ackerman and Chung (1992) used model calculations and the Earth Radiation Budget Experiment (ERBE) data to show that in comparison to clear days, the heavy dust loading over the Saudi Arabian peninsula can change the Top of the Atmosphere (TOA) clear sky shortwave and longwave radiant exitance by 40-90 W/sq m and 5-20 W/sq m, respectively. Large particle concentrations produced from these types of events often are found with optical thicknesses greater than one. These aerosol particles are transported across considerable distances from the source (Fraser et al. 1984). and they could perturb the radiative balance significantly. In this study, the regional radiative effects of aerosols produced from biomass burning, dust storms and forest fires are examined using the Advanced Very High Resolution Radiometer (AVHRR) Local Area

  17. Comparison between soil and biomass carbon in adjacent hardwood and red pine forests

    SciTech Connect

    Perala, D.A.; Rollinger, J.L.; Wilson, D.M.

    1995-06-01

    The distribution of carbon in soil and biomass was studied across Minnesota, Wisconsin, and Michigan, USA, in 40 pole-sized red pine (Pinus resinosa Ait.) plantations paired with adjacent hardwood stands. Pine and hardwood stands shared a common boundary and soil. Hardwood stands were mixed species, naturally regenerated second growth following logging. Carbon in total, standing crop averaged the same in both hardwood and red pine forest types, although the hardwoods averaged 14 years older than red pine. Coarse woody debris, shrubs, and herbs contained little carbon. Only the forest floor carbon pool was significantly different between forest types. Forest floor had a greater mass beneath red pine than hardwoods. There was no difference in total ecosystem carbon between red pine and hardwood stands. Total mineral soil aggregated across the depth profile contained the same total amount of carbon in both pine and hardwood stands; however, the carbon was found in different vertical patterns. Amounts of carbon in the upper levels of soil (0--4 cm) were higher under hardwoods, and amounts were higher under red pine at the 8--16 cm and 16--32 cm soil depths. Where July air temperatures were relatively cool, red pine stored carbon more efficiently both in the forest floor and deep in the soil. Red pine also sequestered more carbon in mineral soil with increasing April--September precipitation.

  18. Validation of modelled forest biomass in Germany using BETHY/DLR

    NASA Astrophysics Data System (ADS)

    Tum, M.; Buchhorn, M.; Günther, K. P.; Haller, B. C.

    2011-11-01

    We present a new approach to the validation of modelled forest Net Primary Productivity (NPP), using empirical data on the mean annual increment, or MAI, in above-ground forest stock. The soil-vegetation-atmosphere-transfer model BETHY/DLR is used, with a particular focus on a detailed parameterization of photosynthesis, to estimate the NPP of forest areas in Germany, driven by remote sensing data from VEGETATION, meteorological data from the European Centre for Medium-Range Weather Forecasts (ECMWF), and additional tree coverage information from the MODIS Vegetation Continuous Field (VCF). The output of BETHY/DLR, Gross Primary Productivity (GPP), is converted to NPP by subtracting the cumulative plant maintenance and growth respiration, and then validated against MAI data that was calculated from German forestry inventories. Validation is conducted for 2000 and 2001 by converting modelled NPP to stem volume at a regional level. Our analysis shows that the presented method fills an important gap in methods for validating modelled NPP against empirically derived data. In addition, we examine theoretical energy potentials calculated from the modelled and validated NPP, assuming sustainable forest management and using species-specific tree heating values. Such estimated forest biomass energy potentials play an important role in the sustainable energy debate.

  19. Incorporating Canopy Cover for Airborne-Derived Assessments of Forest Biomass in the Tropical Forests of Cambodia.

    PubMed

    Singh, Minerva; Evans, Damian; Coomes, David A; Friess, Daniel A; Suy Tan, Boun; Samean Nin, Chan

    2016-01-01

    This research examines the role of canopy cover in influencing above ground biomass (AGB) dynamics of an open canopied forest and evaluates the efficacy of individual-based and plot-scale height metrics in predicting AGB variation in the tropical forests of Angkor Thom, Cambodia. The AGB was modeled by including canopy cover from aerial imagery alongside with the two different canopy vertical height metrics derived from LiDAR; the plot average of maximum tree height (Max_CH) of individual trees, and the top of the canopy height (TCH). Two different statistical approaches, log-log ordinary least squares (OLS) and support vector regression (SVR), were used to model AGB variation in the study area. Ten different AGB models were developed using different combinations of airborne predictor variables. It was discovered that the inclusion of canopy cover estimates considerably improved the performance of AGB models for our study area. The most robust model was log-log OLS model comprising of canopy cover only (r = 0.87; RMSE = 42.8 Mg/ha). Other models that approximated field AGB closely included both Max_CH and canopy cover (r = 0.86, RMSE = 44.2 Mg/ha for SVR; and, r = 0.84, RMSE = 47.7 Mg/ha for log-log OLS). Hence, canopy cover should be included when modeling the AGB of open-canopied tropical forests.

  20. Incorporating Canopy Cover for Airborne-Derived Assessments of Forest Biomass in the Tropical Forests of Cambodia

    PubMed Central

    Singh, Minerva; Evans, Damian; Coomes, David A.; Friess, Daniel A.; Suy Tan, Boun; Samean Nin, Chan

    2016-01-01

    This research examines the role of canopy cover in influencing above ground biomass (AGB) dynamics of an open canopied forest and evaluates the efficacy of individual-based and plot-scale height metrics in predicting AGB variation in the tropical forests of Angkor Thom, Cambodia. The AGB was modeled by including canopy cover from aerial imagery alongside with the two different canopy vertical height metrics derived from LiDAR; the plot average of maximum tree height (Max_CH) of individual trees, and the top of the canopy height (TCH). Two different statistical approaches, log-log ordinary least squares (OLS) and support vector regression (SVR), were used to model AGB variation in the study area. Ten different AGB models were developed using different combinations of airborne predictor variables. It was discovered that the inclusion of canopy cover estimates considerably improved the performance of AGB models for our study area. The most robust model was log-log OLS model comprising of canopy cover only (r = 0.87; RMSE = 42.8 Mg/ha). Other models that approximated field AGB closely included both Max_CH and canopy cover (r = 0.86, RMSE = 44.2 Mg/ha for SVR; and, r = 0.84, RMSE = 47.7 Mg/ha for log-log OLS). Hence, canopy cover should be included when modeling the AGB of open-canopied tropical forests. PMID:27176218

  1. Environmental and economic suitability of forest biomass-based bioenergy production in the Southern United States

    NASA Astrophysics Data System (ADS)

    Dwivedi, Puneet

    This study attempts to ascertain the environmental and economic suitability of utilizing forest biomass for cellulosic ethanol production in the Southern United States. The study is divided into six chapters. The first chapter details the background and defines the relevance of the study along with objectives. The second chapter reviews the existing literature to ascertain the present status of various existing conversion technologies. The third chapter assesses the net energy ratio and global warming impact of ethanol produced from slash pine (Pinus elliottii Engelm.) biomass. A life-cycle assessment was applied to achieve the task. The fourth chapter assesses the role of emerging bioenergy and voluntary carbon markets on the profitability of non-industrial private forest (NIPF) landowners by combining the Faustmann and Hartmann models. The fifth chapter assesses perceptions of four stakeholder groups (Non-Government Organization, Academics, Industries, and Government) on the use of forest biomass for bioenergy production in the Southern United States using the SWOT-AHP (Strength, Weakness, Opportunity, and Threat-Analytical Hierarchy Process) technique. Finally, overall conclusions are made in the sixth chapter. Results indicate that currently the production of cellulosic ethanol is limited as the production cost of cellulosic ethanol is higher than the production cost of ethanol derived from corn. However, it is expected that the production cost of cellulosic ethanol will come down in the future from its current level due to ongoing research efforts. The total global warming impact of E85 fuel (production and consumption) was found as 10.44 tons where as global warming impact of an equivalent amount of gasoline (production and consumption) was 21.45 tons. This suggests that the production and use of ethanol derived from slash pine biomass in the form of E85 fuel in an automobile saves about 51% of carbon emissions when compared to gasoline. The net energy ratio

  2. Effects of Harvesting Intensity and Herbivory by White-tailed Deer on Vegetation and Nutrient Uptake in a Northern Hardwood Forest

    NASA Astrophysics Data System (ADS)

    Yorks, T. E.; Leopold, D. J.; Raynal, D. J.; Murdoch, P. S.; Burns, D. A.

    2003-12-01

    We quantified the response of vegetation and nutrient uptake in a northern hardwood forest in southeastern New York for three to four years after three intensities of harvesting: clearcutting, heavy timber stand improvement (TSI), light TSI (97, 29, and 10% basal area reductions, respectively). We also quantified effects of white-tailed deer (Odocoileus virginianus) herbivory on nutrient retention by vegetation. Total biomass and nutrient accumulation in vegetation was higher after TSI than clearcutting in the first two years but was highest in the fenced clearcut in subsequent years, indicating that TSI or partial harvesting is a viable management tool for harvesting timber while consistently maintaining high rates of nutrient retention. After clearcutting, biomass and nutrient retention were initially dominated by woody stems <1.4 m tall and herbaceous vegetation, but saplings 0.1-5.0 cm DBH became the most important contributors to biomass and nutrient accumulation within four years. However, after both intensities of TSI, trees >5.0 cm DBH continued to account for most biomass and nutrient accumulation whereas understory vegetation accumulated little biomass or nutrients. Heavy TSI resulted in increased regeneration of only two tree species (Acer pensylvanicum, Fagus grandifolia), but clearcutting allowed these two species, mature forest species (A. saccharum, Betula alleghaniensis), and the early successional Prunus pensylvanica to regenerate. Several early successional shrub and herbaceous species were also important to nutrient retention after clearcutting, including Polygonum cilinode, Rubus spp., and Sambucus racemosa. Herbivory by white-tailed deer dramatically reduced biomass and nutrient accumulation by woody stems <5 cm DBH after clearcutting (5.5 vs. 0.7 Mg biomass/ha and 30.4 vs. 6.3 kg N/ha on fenced and unfenced clearcut sites, respectively, after four years), indicating the important influence this herbivore can have on nutrient retention in

  3. Closing a gap in tropical forest biomass estimation: accounting for crown mass variation in pantropical allometries

    NASA Astrophysics Data System (ADS)

    Ploton, P.; Barbier, N.; Momo, S. T.; Réjou-Méchain, M.; Boyemba Bosela, F.; Chuyong, G.; Dauby, G.; Droissart, V.; Fayolle, A.; Goodman, R. C.; Henry, M.; Kamdem, N. G.; Katembo Mukirania, J.; Kenfack, D.; Libalah, M.; Ngomanda, A.; Rossi, V.; Sonké, B.; Texier, N.; Thomas, D.; Zebaze, D.; Couteron, P.; Berger, U.; Pélissier, R.

    2015-12-01

    Accurately monitoring tropical forest carbon stocks is an outstanding challenge. Allometric models that consider tree diameter, height and wood density as predictors are currently used in most tropical forest carbon studies. In particular, a pantropical biomass model has been widely used for approximately a decade, and its most recent version will certainly constitute a reference in the coming years. However, this reference model shows a systematic bias for the largest trees. Because large trees are key drivers of forest carbon stocks and dynamics, understanding the origin and the consequences of this bias is of utmost concern. In this study, we compiled a unique tree mass dataset on 673 trees measured in five tropical countries (101 trees > 100 cm in diameter) and an original dataset of 130 forest plots (1 ha) from central Africa to quantify the error of biomass allometric models at the individual and plot levels when explicitly accounting or not accounting for crown mass variations. We first showed that the proportion of crown to total tree aboveground biomass is highly variable among trees, ranging from 3 to 88 %. This proportion was constant on average for trees < 10 Mg (mean of 34 %) but, above this threshold, increased sharply with tree mass and exceeded 50 % on average for trees ≥ 45 Mg. This increase coincided with a progressive deviation between the pantropical biomass model estimations and actual tree mass. Accounting for a crown mass proxy in a newly developed model consistently removed the bias observed for large trees (> 1 Mg) and reduced the range of plot-level error from -23-16 to 0-10 %. The disproportionally higher allocation of large trees to crown mass may thus explain the bias observed recently in the reference pantropical model. This bias leads to far-from-negligible, but often overlooked, systematic errors at the plot level and may be easily corrected by accounting for a crown mass proxy for the largest trees in a stand, thus suggesting that

  4. Community structure, diversity and total biomass of tree species at Kapur dominated forests in Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Norafida, N. A. Nik; Nizam, M. S.; Juliana, W. A. Wan

    2013-11-01

    A study was conducted to determine the species composition, diversity and biomass of Kapur (Dryobalanops aromatica Gaertn.f.) dominated forests in Peninsular Malaysia. Three forests were selected in different geographical zones, namely Bukit Bauk Virgin Jungle Reserve (BBVJR), Terengganu, Lesong Forest Reserve (LFR), Pahang and Gunung Belumut Recreational Forest (GBRF), Johor. Thirty plots of 0.1 ha (50 m × 20 m) were established with a total sampling area of 1.0 ha at each forest site. All trees with ≥5 cm diameter at breast height (dbh) were tagged, measured and voucher specimens were collected. Floristic composition in the study plot at BBVJR recorded 55 families, 147 genera and 336 species. In LFR, there were 52 families, 138 genera and 288 species, whereas in GBRF there were 52 families, 132 genera and 271 species. D. aromatica was the most important species in all study plots with the Importance Value Index (IVi) of 17.81%, 23.01% and 16.25% in BBVJR, LFR and GBRF, respectively. Similar trend at family level showed the Dipterocarpaceae was the most important family in each of the areas with the family Importance Value Index (FIVi) of 27.95% (BBVJR), 26.09% (LFR) and 27.16% (GBRF). Shannon diversity index (H'f) and Shannon evenness index (J'f) of trees at BBVJR was 5.02 and 0.86; LFR was 4.63 and 0.82; and GBRF was 4.82 and 0.86, respectively. Sorensen's community similarity coefficient (CCs) showed that tree communities between BBVJR, LFR and GBRF had low similarities with values of 0.3 to 0.4. The highest total biomass estimated was in LFR with a value of 739.44 t/ha, followed by BBVJR at 701.34 t/ha and GBRF at 606.29 t/ha.

  5. Forest Composition and Biomass at Euroamerican Settlement in the Upper Great Lakes

    NASA Astrophysics Data System (ADS)

    Williams, J. W.; Goring, S. J.; Brooks, W.; Cogbill, C.; Dietze, M. C.; Jackson, S. T.; McLachlan, J. S.; Mladenoff, D. J.; Paciorek, C.; Thurman, A.; Zhu, J.

    2012-12-01

    The Paleoecological Observatory Network (PalEON) is a collaborative team of paleoecologists, ecological statisticians, and ecosystem modelers with the goals of a) reconstructing forest composition, fire regime, and climate variability in northeastern US forests for the past 2000 years, and b) applying this knowledge to develop more accurate simulations of forest dynamics for the 20th and 21st-century. A major on-going effort in PalEON is to develop high-quality gridded land-cover datasets for the last 2000 years, by combining Public Lands Survey (PLS) and fossil pollen data. Here we present 5-arcmin gridded reconstructions of forest composition, stem density, and basal area for Minnesota, Wisconsin, and upper Michigan, at the time of Euroamerican land surveying, ca. 1850AD. All PLS taxonomic names have been standardized and only tree identifications from the closest two trees at corner points were used. Forest composition and uncertainty was modeled using Bayesian hierarchical model with conditional autoregression and a Gibbs sampler. We are in the process of developing statistical models to characterize the spatial uncertainty in the stem density and biomass reconstructions. Work is underway to merge these reconstructions of forest composition with township data on forest composition for the New England States (Cogbill, 2002) and additional PLS data from lower Michigan, Ohio, Indiana, and Illinois. The PalEON reconstructions of settlement-era vegetation broadly agree with the potential vegetation maps of Ramankutty and Foley (1999); however, the PalEON reconstructions reveal a much higher spatial heterogeneity and more diffuse ecotones between major vegetation formations. These reconstructions will be applied to validate ecosystem model simulations in the PalEON model intercomparison project and set baselines for future simulations, and should improve regional-scale modeling of processes such as fire dynamics, vegetation-atmospheric feedbacks, and carbon cycling.

  6. Measuring forest structure and biomass using EchidnaRTM ground-based lidar

    NASA Astrophysics Data System (ADS)

    Yao, Tian

    Forest canopy structural parameters and above-ground biomass, retrieved by a ground-based, upward-scanning, near-infrared (1064 nm), full-waveform lidar, the EchidnaRTM Validation Instrument (EVI), matched ground measurements with R2 values of 0.92 to 0.99 at six hardwood and conifer forest sites within New England in 2007 and at eight conifer forest sites in the Sierra National Forest in California in 2008. Retrieved parameters included mean diameter at breast height (DBH), stem count density, basal area, and above-ground biomass, based on five scans within each 1-ha plot. Canopy heights derived from the EVI-retrieved foliage profile closely matched those derived from the airborne Laser Vegetation Imaging Sensor (LVIS). Topographic slope can induce errors in parameter retrievals because the horizontal plane of the instrument scan, which is used to identify, measure, and count tree trunks, will intersect trunks below breast height in the uphill direction and above breast height in the downhill direction. I tested three methods of slope correction on the Sierra sites. Without correction, single-scan correlations of structural parameters with field measurements ranged from 0.53-0.86; after correction, from 0.78-0.91, 0.80-0.93 and 0,85-0.93 for the three methods respectively. These results document the importance of the slope correction in EVI structural retrievals. Three sites scanned in 2007 provided the opportunity to detect change in comparison to 2009 or 2010 scans. At a shelterwood conifer site at Howland Experimental Forest, mean DBH, above-ground biomass, and leaf area index (LAI) all increased between 2007 and 2009. An ice storm struck the Harvard Forest in December, 2008, providing the opportunity to detect damage between 2007 and 2009 or 2010 EVI scans at two sites there: hemlock and hardwood. Retrieved leaf area index (LAI) was 13 percent lower in the hemlock site in 2009 and 10 percent lower in the hardwood site in 2010. Broken tops were visible in the

  7. Looking for age-related growth decline in natural forests: unexpected biomass patterns from tree rings and simulated mortality

    USGS Publications Warehouse

    Foster, Jane R.; D'Amato, Anthony W.; Bradford, John B.

    2014-01-01

    Forest biomass growth is almost universally assumed to peak early in stand development, near canopy closure, after which it will plateau or decline. The chronosequence and plot remeasurement approaches used to establish the decline pattern suffer from limitations and coarse temporal detail. We combined annual tree ring measurements and mortality models to address two questions: first, how do assumptions about tree growth and mortality influence reconstructions of biomass growth? Second, under what circumstances does biomass production follow the model that peaks early, then declines? We integrated three stochastic mortality models with a census tree-ring data set from eight temperate forest types to reconstruct stand-level biomass increments (in Minnesota, USA). We compared growth patterns among mortality models, forest types and stands. Timing of peak biomass growth varied significantly among mortality models, peaking 20–30 years earlier when mortality was random with respect to tree growth and size, than when mortality favored slow-growing individuals. Random or u-shaped mortality (highest in small or large trees) produced peak growth 25–30 % higher than the surviving tree sample alone. Growth trends for even-aged, monospecific Pinus banksiana or Acer saccharum forests were similar to the early peak and decline expectation. However, we observed continually increasing biomass growth in older, low-productivity forests of Quercus rubra, Fraxinus nigra, and Thuja occidentalis. Tree-ring reconstructions estimated annual changes in live biomass growth and identified more diverse development patterns than previous methods. These detailed, long-term patterns of biomass development are crucial for detecting recent growth responses to global change and modeling future forest dynamics.

  8. Looking for age-related growth decline in natural forests: unexpected biomass patterns from tree rings and simulated mortality.

    PubMed

    Foster, Jane R; D'Amato, Anthony W; Bradford, John B

    2014-05-01

    Forest biomass growth is almost universally assumed to peak early in stand development, near canopy closure, after which it will plateau or decline. The chronosequence and plot remeasurement approaches used to establish the decline pattern suffer from limitations and coarse temporal detail. We combined annual tree ring measurements and mortality models to address two questions: first, how do assumptions about tree growth and mortality influence reconstructions of biomass growth? Second, under what circumstances does biomass production follow the model that peaks early, then declines? We integrated three stochastic mortality models with a census tree-ring data set from eight temperate forest types to reconstruct stand-level biomass increments (in Minnesota, USA). We compared growth patterns among mortality models, forest types and stands. Timing of peak biomass growth varied significantly among mortality models, peaking 20-30 years earlier when mortality was random with respect to tree growth and size, than when mortality favored slow-growing individuals. Random or u-shaped mortality (highest in small or large trees) produced peak growth 25-30% higher than the surviving tree sample alone. Growth trends for even-aged, monospecific Pinus banksiana or Acer saccharum forests were similar to the early peak and decline expectation. However, we observed continually increasing biomass growth in older, low-productivity forests of Quercus rubra, Fraxinus nigra, and Thuja occidentalis. Tree-ring reconstructions estimated annual changes in live biomass growth and identified more diverse development patterns than previous methods. These detailed, long-term patterns of biomass development are crucial for detecting recent growth responses to global change and modeling future forest dynamics.

  9. The influence of light intensity and photoperiod on duckweed biomass and starch accumulation for bioethanol production.

    PubMed

    Yin, Yehu; Yu, Changjiang; Yu, Li; Zhao, Jinshan; Sun, Changjiang; Ma, Yubin; Zhou, Gongke

    2015-01-01

    Duckweed has been considered as a valuable feedstock for bioethanol production due to its high biomass and starch production. To investigate the effects of light conditions on duckweed biomass and starch production, Lemna aequinoctialis 6000 was cultivated at different photoperiods (12:12, 16:8 and 24:0h) and light intensities (20, 50, 80, 110, 200 and 400μmolm(-2)s(-1)). The results showed that the duckweed biomass and starch production was increased with increasing light intensity and photoperiod except at 200 and 400μmolm(-2)s(-1). Considering the light cost, 110μmolm(-2)s(-1) was optimum light condition for starch accumulation with the highest maximum growth rate, biomass and starch production of 8.90gm(-2)day(-1), 233.25gm(-2) and 98.70gm(-2), respectively. Moreover, the results suggested that high light induction was a promising method for duckweed starch accumulation. This study provides optimized light conditions for future industrial large-scale duckweed cultivation.

  10. Estimation of Tropical Forest Height and Biomass Dynamics Using Lidar Remote Sensing at La Selva, Costa Rica

    NASA Astrophysics Data System (ADS)

    Dubayah, R.; Sheldon, S. L.; Clark, D. B.; Hofton, M. A.; Blair, J. B.; Hurtt, G. C.; Chazdon, R.

    2009-12-01

    In this paper we reexamine the results of an experiment to measure forest structure and biomass dynamics over the tropical forests of La Selva Biological Station in Costa Rica using a medium resolution lidar. Our main objective was to observe changes in forest canopy height, related height metrics, and biomass, and from these map sources and sinks of carbon across the landscape. The Laser Vegetation Imaging Sensor (LVIS) measured canopy structure over La Selva in 1998 and again in 2005. Changes in waveform metrics were related to field-derived changes in estimated aboveground biomass from a series of old growth and secondary forest plots. Pair wise comparisons of nearly coincident lidar footprints between years showed canopy top height changes that coincided with expected changes based on land cover types. Old growth forests had a net loss in height of -0.33 m, while secondary forests had net gain of 2.08 m. Multiple linear regression was used to relate lidar metrics with biomass changes for combined old growth and secondary forest plots, giving an r2 of 0.65 and an RSE of 10.5 Mg/ha, but both parametric and bootstrapped confidence intervals were wide, suggesting weaker model performance. The plot level relationships were then used to map biomass changes across La Selva using LVIS at a one ha scale. The spatial patterns of biomass changes matched expected patterns given the distribution of land cover types at La Selva, with secondary forests showing a gain of 25 Mg/ha and old growth forests showing little change (2 Mg/ha). When statistical uncertainty was included in our analysis most of the old growth areas appeared as neutral (no net biomass change), with widely scattered and isolated sources and sinks. Secondary forests in contrast were mostly sinks or neutral, but were never sources. By quantifying both the magnitude of biomass changes and the sensitivity of lidar to detect them, this work will help inform the formulation of future space missions focused on

  11. Intensive use of biomass feedstock in ethanol conversion: The alcohol-water, vapor-phase separation

    SciTech Connect

    Robertson, G.H.; Doyle, L.R.; Pavlath, A.E.

    1983-12-01

    Fermentation of ethanol in a system whereby the biomass is used intensively (both to separate alcohol from water by vapor phase adsorption and to serve as the feedstock) is shown to be possible on theoretical grounds when the biomass is grain. The rationale for a vapor-phase adsorption process as an alternative to distillation is shown to be energetically valid above 84 wt % ethanol. The capacity of grain in new vapor-phase ambient adsorption processes was estimated experimentally with the finding that sufficient capacity exists for the intensive use but that the adsorption is dynamically controlled so that the grain form and particle size are important. Pretreatments such as explosive dehydration improve the transfer of water to the grain in adsorption with potential improvement in the efficiency of liquefaction and saccharification. At room temperature, these sorbents are not perfectly selective for water but adsorb ethanol which will be carried to the liquefaction, saccharification, and fermentation with the feedstock.

  12. Impact of forest biomass residues to the energy supply chain on regional air quality.

    PubMed

    Rafael, S; Tarelho, L; Monteiro, A; Sá, E; Miranda, A I; Borrego, C; Lopes, M

    2015-02-01

    The increase of the share of renewable energy in Portugal can be met from different sources, of which forest biomass residues (FBR) can play a main role. Taking into account the demand for information about the strategy of FBR to energy, and its implications on the Portuguese climate policy, the impact of energy conversion of FBR on air quality is evaluated. Three emission scenarios were defined and a numerical air quality model was selected to perform this evaluation. The results reveal that the biomass thermal plants contribute to an increment of the pollutant concentrations in the atmosphere, however restricted to the surrounding areas of the thermal plants, and most significant for NO₂ and O₃.

  13. Maximizing Conservation and Production with Intensive Forest Management: It's All About Location.

    PubMed

    Tittler, Rebecca; Filotas, Élise; Kroese, Jasmin; Messier, Christian

    2015-11-01

    Functional zoning has been suggested as a way to balance the needs of a viable forest industry with those of healthy ecosystems. Under this system, part of the forest is set aside for protected areas, counterbalanced by intensive and extensive management of the rest of the forest. Studies indicate this may provide adequate timber while minimizing road construction and favoring the development of large mature and old stands. However, it is unclear how the spatial arrangement of intensive management areas may affect the success of this zoning. Should these areas be agglomerated or dispersed throughout the forest landscape? Should managers prioritize (a) proximity to existing roads, (b) distance from protected areas, or (c) site-specific productivity? We use a spatially explicit landscape simulation model to examine the effects of different spatial scenarios on landscape structure, connectivity for native forest wildlife, stand diversity, harvest volume, and road construction: (1) random placement of intensive management areas, and (2-8) all possible combinations of rules (a)-(c). Results favor the agglomeration of intensive management areas. For most wildlife species, connectivity was the highest when intensive management was far from the protected areas. This scenario also resulted in relatively high harvest volumes. Maximizing distance of intensive management areas from protected areas may therefore be the best way to maximize the benefits of intensive management areas while minimizing their potentially negative effects on forest structure and biodiversity.

  14. Maximizing Conservation and Production with Intensive Forest Management: It's All About Location

    NASA Astrophysics Data System (ADS)

    Tittler, Rebecca; Filotas, Élise; Kroese, Jasmin; Messier, Christian

    2015-11-01

    Functional zoning has been suggested as a way to balance the needs of a viable forest industry with those of healthy ecosystems. Under this system, part of the forest is set aside for protected areas, counterbalanced by intensive and extensive management of the rest of the forest. Studies indicate this may provide adequate timber while minimizing road construction and favoring the development of large mature and old stands. However, it is unclear how the spatial arrangement of intensive management areas may affect the success of this zoning. Should these areas be agglomerated or dispersed throughout the forest landscape? Should managers prioritize (a) proximity to existing roads, (b) distance from protected areas, or (c) site-specific productivity? We use a spatially explicit landscape simulation model to examine the effects of different spatial scenarios on landscape structure, connectivity for native forest wildlife, stand diversity, harvest volume, and road construction: (1) random placement of intensive management areas, and (2-8) all possible combinations of rules (a)-(c). Results favor the agglomeration of intensive management areas. For most wildlife species, connectivity was the highest when intensive management was far from the protected areas. This scenario also resulted in relatively high harvest volumes. Maximizing distance of intensive management areas from protected areas may therefore be the best way to maximize the benefits of intensive management areas while minimizing their potentially negative effects on forest structure and biodiversity.

  15. Biomass energy

    SciTech Connect

    Smil, V.

    1983-01-01

    This book offers a broad, interdisciplinary approach to assessing the factors that are key determinants to the use of biomass energies, stressing their limitations, complexities, uncertainties, links, and consequences. Considers photosynthesis, energy costs of nutrients, problems with monoculture, and the energy analysis of intensive tree plantations. Subjects are examined in terms of environmental and economic impact. Emphasizes the use and abuse of biomass energies in China, India, and Brazil. Topics include forests, trees for energy, crop residues, fuel crops, aquatic plants, and animal and human wastes. Recommended for environmental engineers and planners, and those involved in ecology, systematics, and forestry.

  16. Effects of nitrogen and phosphorus additions on soil microbial biomass and community structure in two reforested tropical forests

    NASA Astrophysics Data System (ADS)

    Liu, Lei; Gundersen, Per; Zhang, Wei; Zhang, Tao; Chen, Hao; Mo, Jiangming

    2015-09-01

    Elevated nitrogen (N) deposition may aggravate phosphorus (P) deficiency in forests in the warm humid regions of China. To our knowledge, the interactive effects of long-term N deposition and P availability on soil microorganisms in tropical replanted forests remain unclear. We conducted an N and P manipulation experiment with four treatments: control, N addition (15 g N m-2·yr-1), P addition (15 g P m-2·yr-1), and N and P addition (15 + 15 g N and P m-2·yr-1, respectively) in disturbed (planted pine forest with recent harvests of understory vegetation and litter) and rehabilitated (planted with pine, but mixed with broadleaf returning by natural succession) forests in southern China. Nitrogen addition did not significantly affect soil microbial biomass, but significantly decreased the abundance of gram-negative bacteria PLFAs in both forest types. Microbial biomass increased significantly after P addition in the disturbed forest but not in the rehabilitated forest. No interactions between N and P additions on soil microorganisms were observed in either forest type. Our results suggest that microbial growth in replanted forests of southern China may be limited by P rather than by N, and this P limitation may be greater in disturbed forests.

  17. Effects of nitrogen and phosphorus additions on soil microbial biomass and community structure in two reforested tropical forests.

    PubMed

    Liu, Lei; Gundersen, Per; Zhang, Wei; Zhang, Tao; Chen, Hao; Mo, Jiangming

    2015-09-23

    Elevated nitrogen (N) deposition may aggravate phosphorus (P) deficiency in forests in the warm humid regions of China. To our knowledge, the interactive effects of long-term N deposition and P availability on soil microorganisms in tropical replanted forests remain unclear. We conducted an N and P manipulation experiment with four treatments: control, N addition (15 g N m(-2)·yr(-1)), P addition (15 g P m(-2)·yr(-1)), and N and P addition (15 + 15 g N and P m(-2)·yr(-1), respectively) in disturbed (planted pine forest with recent harvests of understory vegetation and litter) and rehabilitated (planted with pine, but mixed with broadleaf returning by natural succession) forests in southern China. Nitrogen addition did not significantly affect soil microbial biomass, but significantly decreased the abundance of gram-negative bacteria PLFAs in both forest types. Microbial biomass increased significantly after P addition in the disturbed forest but not in the rehabilitated forest. No interactions between N and P additions on soil microorganisms were observed in either forest type. Our results suggest that microbial growth in replanted forests of southern China may be limited by P rather than by N, and this P limitation may be greater in disturbed forests.

  18. Effects of nitrogen and phosphorus additions on soil microbial biomass and community structure in two reforested tropical forests

    PubMed Central

    Liu, Lei; Gundersen, Per; Zhang, Wei; Zhang, Tao; Chen, Hao; Mo, Jiangming

    2015-01-01

    Elevated nitrogen (N) deposition may aggravate phosphorus (P) deficiency in forests in the warm humid regions of China. To our knowledge, the interactive effects of long-term N deposition and P availability on soil microorganisms in tropical replanted forests remain unclear. We conducted an N and P manipulation experiment with four treatments: control, N addition (15 g N m−2·yr−1), P addition (15 g P m−2·yr−1), and N and P addition (15 + 15 g N and P m−2·yr−1, respectively) in disturbed (planted pine forest with recent harvests of understory vegetation and litter) and rehabilitated (planted with pine, but mixed with broadleaf returning by natural succession) forests in southern China. Nitrogen addition did not significantly affect soil microbial biomass, but significantly decreased the abundance of gram-negative bacteria PLFAs in both forest types. Microbial biomass increased significantly after P addition in the disturbed forest but not in the rehabilitated forest. No interactions between N and P additions on soil microorganisms were observed in either forest type. Our results suggest that microbial growth in replanted forests of southern China may be limited by P rather than by N, and this P limitation may be greater in disturbed forests. PMID:26395406

  19. Biological feedbacks dominate environmental sensitivity of net biomass production in temperate and boreal North American forests

    NASA Astrophysics Data System (ADS)

    Hember, R. A.; Kurz, W. A.; Coops, N.; Boisvenue, C.; Metsaranta, J. M.

    2012-12-01

    Considerable uncertainty remains in how environmental changes are impacting forest biomass dynamics. Here, we analyze a large sample of permanent sample plots and tree-ring chronologies from temperate and boreal forests across North America to empirically derive environmental sensitivity and constrain ecophysiological model simulations of biomass growth (G) and mortality (M). We argue that observed cross-site variation of G for common forest types reflects a combination of genetic differentiation and equilibrium sensitivity to environmental conditions. Growth of all tested tree species exhibited greater than expected exponential sensitivity to temperature and widely varying responses to water deficits. A high degree of persistence in temporal responses of G to environmental change, evident in both tree-ring chronologies and models, suggests that high estimates of equilibrium sensitivity derived from cross-site variation may be attributed to biological feedbacks (e.g., leaf area expansion) that delay and amplify environmental sensitivity above levels more often inferred from short-term transient variation. Long-term plots and tree-ring chronologies in western North America suggest that environmental changes contributed to significant enhancement of G over the 20th century. Increases in M above background levels were triggered by a critical level of modelled actual evapotranspiration (ETa). Leaf area expansion and consequent positive trends in transpiration were the primary factors causing stands to exceed critical levels of ETa. Positive dependence of M on transpiration led us to propose that hydraulic failure may be the primary mechanism causing drought-induced regular mortality and that recent trends may reflect a negative feedback response to 20th century growth enhancement that allowed biomass to build up to levels that were eventually unsustainable through the 1980's and 90's droughts. The effect of the mortality feedback on net biomass production (ΔB) is

  20. Spatially explicit estimation of aboveground boreal forest biomass in the Yukon River Basin, Alaska

    USGS Publications Warehouse

    Ji, Lei; Wylie, Bruce K.; Brown, Dana R. N.; Peterson, Birgit E.; Alexander, Heather D.; Mack, Michelle C.; Rover, Jennifer R.; Waldrop, Mark P.; McFarland, Jack W.; Chen, Xuexia; Pastick, Neal J.

    2015-01-01

    Quantification of aboveground biomass (AGB) in Alaska’s boreal forest is essential to the accurate evaluation of terrestrial carbon stocks and dynamics in northern high-latitude ecosystems. Our goal was to map AGB at 30 m resolution for the boreal forest in the Yukon River Basin of Alaska using Landsat data and ground measurements. We acquired Landsat images to generate a 3-year (2008–2010) composite of top-of-atmosphere reflectance for six bands as well as the brightness temperature (BT). We constructed a multiple regression model using field-observed AGB and Landsat-derived reflectance, BT, and vegetation indices. A basin-wide boreal forest AGB map at 30 m resolution was generated by applying the regression model to the Landsat composite. The fivefold cross-validation with field measurements had a mean absolute error (MAE) of 25.7 Mg ha−1 (relative MAE 47.5%) and a mean bias error (MBE) of 4.3 Mg ha−1(relative MBE 7.9%). The boreal forest AGB product was compared with lidar-based vegetation height data; the comparison indicated that there was a significant correlation between the two data sets.

  1. The Uncertainty of Biomass Estimates from Modeled ICESat-2 Returns Across a Boreal Forest Gradient

    NASA Technical Reports Server (NTRS)

    Montesano, P. M.; Rosette, J.; Sun, G.; North, P.; Nelson, R. F.; Dubayah, R. O.; Ranson, K. J.; Kharuk, V.

    2014-01-01

    The Forest Light (FLIGHT) radiative transfer model was used to examine the uncertainty of vegetation structure measurements from NASA's planned ICESat-2 photon counting light detection and ranging (LiDAR) instrument across a synthetic Larix forest gradient in the taiga-tundra ecotone. The simulations demonstrate how measurements from the planned spaceborne mission, which differ from those of previous LiDAR systems, may perform across a boreal forest to non-forest structure gradient in globally important ecological region of northern Siberia. We used a modified version of FLIGHT to simulate the acquisition parameters of ICESat-2. Modeled returns were analyzed from collections of sequential footprints along LiDAR tracks (link-scales) of lengths ranging from 20 m-90 m. These link-scales traversed synthetic forest stands that were initialized with parameters drawn from field surveys in Siberian Larix forests. LiDAR returns from vegetation were compiled for 100 simulated LiDAR collections for each 10 Mg · ha(exp -1) interval in the 0-100 Mg · ha(exp -1) above-ground biomass density (AGB) forest gradient. Canopy height metrics were computed and AGB was inferred from empirical models. The root mean square error (RMSE) and RMSE uncertainty associated with the distribution of inferred AGB within each AGB interval across the gradient was examined. Simulation results of the bright daylight and low vegetation reflectivity conditions for collecting photon counting LiDAR with no topographic relief show that 1-2 photons are returned for 79%-88% of LiDAR shots. Signal photons account for approximately 67% of all LiDAR returns, while approximately 50% of shots result in 1 signal photon returned. The proportion of these signal photon returns do not differ significantly (p greater than 0.05) for AGB intervals greater than 20 Mg · ha(exp -1). The 50m link-scale approximates the finest horizontal resolution (length) at which photon counting LiDAR collection provides strong model

  2. Effects of bark beetle outbreaks on species composition, biomass, and nutrient distribution in a mixed deciduous forest

    SciTech Connect

    Johnson, D.W.; Henderson, G.S.; Harris, W.F.

    1987-01-01

    The increment of forest biomass and nutrient content on Walker Branch Watershed, Tennessee, from 1967 to 1983 was interrupted by two bark beetle outbreaks. An outbreak of the southern pine beetle in the early 1970s and an outbreak of the hickory borer in the late 1970s, early 1980s killed a number of shortleaf pine (Pinus echinata) and hickory (Carya spp.) respectively. Yellow-poplar (Liriodendron tulipifera) growth increased over this 16-year period, especially in response to the mortality of shortleaf pine. The net result of these events was little change in total biomass but a substantial shift in species composition (from pine to yellow-poplar) in the Pine forest type over this period. No species has yet responded to the mortality of hickory. Due to the shift in species composition in the Pine type, calcium and magnesium accumulation rates in biomass increased but foliage biomass decreased over the inventory period. There was little change in foliage biomass or nutrient content in other forest types. The beetle attacks, combined with apparently natural self-thinning, caused a large increase in standing dead biomass and in nutrient return via tree fall. This increased rate of return will substantially alter forest floor nutrient content and availability, especially with regard to calcium and nitrogen.

  3. Chemometric modeling of thermogravimetric data for the compositional analysis of forest biomass

    PubMed Central

    Via, Brian K.; Fasina, Oladiran O.; Adhikari, Sushil; Billor, Nedret; Eckhardt, Lori G.

    2017-01-01

    The objective of this study was to investigated the use of chemometric modeling of thermogravimetric (TG) data as an alternative approach to estimate the chemical and proximate (i.e. volatile matter, fixed carbon and ash contents) composition of lignocellulosic biomass. Since these properties affect the conversion pathway, processing costs, yield and / or quality of products, a capability to rapidly determine these for biomass feedstock entering the process stream will be useful in the success and efficiency of bioconversion technologies. The 38-minute long methodology developed in this study enabled the simultaneous prediction of both the chemical and proximate properties of forest-derived biomass from the same TG data. Conventionally, two separate experiments had to be conducted to obtain such information. In addition, the chemometric models constructed with normalized TG data outperformed models developed via the traditional deconvolution of TG data. PLS and PCR models were especially robust in predicting the volatile matter (R2–0.92; RPD– 3.58) and lignin (R2–0.82; RPD– 2.40) contents of the biomass. The application of chemometrics to TG data also made it possible to predict some monomeric sugars in this study. Elucidation of PC loadings obtained from chemometric models also provided some insights into the thermal decomposition behavior of the chemical constituents of lignocellulosic biomass. For instance, similar loadings were noted for volatile matter and cellulose, and for fixed carbon and lignin. The findings indicate that common latent variables are shared between these chemical and thermal reactivity properties. Results from this study buttresses literature that have reported that the less thermally stable polysaccharides are responsible for the yield of volatiles whereas the more recalcitrant lignin with its higher percentage of elementary carbon contributes to the yield of fixed carbon. PMID:28253322

  4. Mapping tropical forest biomass with radar and spaceborne LiDAR in Lopé National Park, Gabon: overcoming problems of high biomass and persistent cloud

    NASA Astrophysics Data System (ADS)

    Mitchard, E. T. A.; Saatchi, S. S.; White, L. J. T.; Abernethy, K. A.; Jeffery, K. J.; Lewis, S. L.; Collins, M.; Lefsky, M. A.; Leal, M. E.; Woodhouse, I. H.; Meir, P.

    2012-01-01

    Spatially-explicit maps of aboveground biomass are essential for calculating the losses and gains in forest carbon at a regional to national level. The production of such maps across wide areas will become increasingly necessary as international efforts to protect primary forests, such as the REDD+ (Reducing Emissions from Deforestation and forest Degradation) mechanism, come into effect, alongside their use for management and research more generally. However, mapping biomass over high-biomass tropical forest is challenging as (1) direct regressions with optical and radar data saturate, (2) much of the tropics is persistently cloud-covered, reducing the availability of optical data, (3) many regions include steep topography, making the use of radar data complex, (5) while LiDAR data does not suffer from saturation, expensive aircraft-derived data are necessary for complete coverage. We present a solution to the problems, using a combination of terrain-corrected L-band radar data (ALOS PALSAR), spaceborne LiDAR data (ICESat GLAS) and ground-based data. We map Gabon's Lopé National Park (5000 km2) because it includes a range of vegetation types from savanna to closed-canopy tropical forest, is topographically complex, has no recent contiguous cloud-free high-resolution optical data, and the dense forest is above the saturation point for radar. Our 100 m resolution biomass map is derived from fusing spaceborne LiDAR (7142 ICESat GLAS footprints), 96 ground-based plots (average size 0.8 ha) and an unsupervised classification of terrain-corrected ALOS PALSAR radar data, from which we derive the aboveground biomass stocks of the park to be 78 Tg C (173 Mg C ha-1). This value is consistent with our field data average of 181 Mg C ha-1, from the field plots measured in 2009 covering a total of 78 ha, and which are independent as they were not used for the GLAS-biomass estimation. We estimate an uncertainty of ±25% on our carbon stock value for the park. This error term

  5. Above ground biomass estimation from lidar and hyperspectral airbone data in West African moist forests.

    NASA Astrophysics Data System (ADS)

    Vaglio Laurin, Gaia; Chen, Qi; Lindsell, Jeremy; Coomes, David; Cazzolla-Gatti, Roberto; Grieco, Elisa; Valentini, Riccardo

    2013-04-01

    The development of sound methods for the estimation of forest parameters such as Above Ground Biomass (AGB) and the need of data for different world regions and ecosystems, are widely recognized issues due to their relevance for both carbon cycle modeling and conservation and policy initiatives, such as the UN REDD+ program (Gibbs et al., 2007). The moist forests of the Upper Guinean Belt are poorly studied ecosystems (Vaglio Laurin et al. 2013) but their role is important due to the drier condition expected along the West African coasts according to future climate change scenarios (Gonzales, 2001). Remote sensing has proven to be an effective tool for AGB retrieval when coupled with field data. Lidar, with its ability to penetrate the canopy provides 3D information and best results. Nevertheless very limited research has been conducted in Africa tropical forests with lidar and none to our knowledge in West Africa. Hyperspectral sensors also offer promising data, being able to evidence very fine radiometric differences in vegetation reflectance. Their usefulness in estimating forest parameters is still under evaluation with contrasting findings (Andersen et al. 2008, Latifi et al. 2012), and additional studies are especially relevant in view of forthcoming satellite hyperspectral missions. In the framework of the EU ERC Africa GHG grant #247349, an airborne campaign collecting lidar and hyperspectral data has been conducted in March 2012 over forests reserves in Sierra Leone and Ghana, characterized by different logging histories and rainfall patterns, and including Gola Rainforest National Park, Ankasa National Park, Bia and Boin Forest Reserves. An Optech Gemini sensor collected the lidar dataset, while an AISA Eagle sensor collected hyperspectral data over 244 VIS-NIR bands. The lidar dataset, with a point density >10 ppm was processed using the TIFFS software (Toolbox for LiDAR Data Filtering and Forest Studies)(Chen 2007). The hyperspectral dataset, geo

  6. Leaf Area Index and Biomass Assessment over Tropical Peatland Forest Ecosystem Using ALOS PalSAR and Envisat ASAR Data

    NASA Astrophysics Data System (ADS)

    Wijaya, Arief; Susanti, Ari; Liesenberg, Veraldo; Wardhana, Wahyu; Yanto, Edi; Soeprijadi, Djoko; McFarlane, Craig; Qomar, Nurul

    2011-03-01

    Provision of accurate forest parameter properties is important as a basis for forest resources monitoring and carbon cycle assessment. The present study aims to model leaf area index (LAI), above ground biomass and carbon stocks over tropical peatland forests using single polarization SAR, full polarimetry SAR (PolSAR) data. Single band ALOS Palsar data (HH band, acquired on November 17, 2008) and polarimetric data (HH, VV, HV and VH, collected on April 4 and May 5, 2007) are used for the study. A series of ENVISAT ASAR data (5 datasets) collected in 2004 - 2005 are also used to model the forest properties. Landsat ETM data collected on January 22, 2009 is also used as a reference. The relationship between forest parameters and normalized radar backscattering is estimated using empirical models, and preliminary results show that Polarimetric SAR data has better correlations with the LAI and biomass than single polarimetry SAR data. The field data were collected during field work in March - April 2009 and the reliability of identified forest classes was also assessed from available Landsat ETM data. Analysis will be conducted on the basis of statistical correlations between radar data and modeled forest properties, such as LAI, biomass and tree age. This study focuses on a unique tropical peatland ecosystem in Kampar Peninsula, Sumatera, Indonesia, which has great potentials as carbon sinks and/or sources. Only few studies have been conducted in the study area due to limited satellite and field observation data.

  7. A montane Mediterranean climate supports year-round photosynthesis and high forest biomass.

    PubMed

    Kelly, Anne E; Goulden, Michael L

    2016-04-01

    The mid-elevation forest of California's Sierra Nevada poses a bioclimatic paradox. Mid-elevation trees experience a montane Mediterranean climate, with near-freezing winter days and rain-free summers. The asynchrony between warmth and water input suggests low primary production, limited by photosynthetic dormancy in winter cold, and again in summer and early autumn with drought, yet this forest is characterized by tall trees and high biomass. We used eddy covariance in a mid-elevation Sierra stand to understand how winter cold and summer drought limit canopy photosynthesis and production. The trees exhibited canopy photosynthesis year-round. Trees avoided winter dormancy, and daytime CO2uptake continued despite a deep snowpack and near-freezing temperatures. Photosynthesis on sunny days continued at half of maximum rates when air temperature was 0 °C. Likewise, the vegetation avoided summer drought dormancy, and high rates of daytime CO2uptake and transpiration continued despite a 5-month period with only negligible water input. We attribute this drought avoidance to deep rooting and availability of deep soil water. Year-round photosynthesis helps explain the large biomass observed in the Sierra Nevada, and implies adaptive strategies that may contribute to the resiliency or vulnerability of Sierran vegetation to climate change.

  8. Study of production functions for modeling forest biomass: An area for research

    SciTech Connect

    Nautiyal, J.C. ); Belli, K.L. )

    1989-09-01

    The usefulness of production functions, mathematical descriptions of production processes, has long been recognized by economists in manufacturing industries, and more recently by agricultural scientists in the field of biological production. As increasing emphasis in forestry is placed on short-rotation, intensive crop management it would seem that foresters would also require production functions for rational timber management planning. These functions could be useful in a number of areas such as: crop tree growth prediction, control of stand development, economic analysis for decision-making purposes, and for determining the so-called elasticities of inputs and outputs. A very general functional form that may be appropriate for the development of forestry models is the transcendental logarithmic, or translog, function. Unfortunately, at this time, sufficiently detailed data do not seem to be available for any tree species to estimate a production function that could make sophisticated intensive forest management possible.

  9. Biomass, production and woody detritus in an old coast redwood (Sequoia sempervirens) forest

    USGS Publications Warehouse

    Busing, R.T.; Fujimori, T.

    2005-01-01

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

  10. Elevated CO2 enrichment induces a differential biomass response in a mixed species temperate forest plantation.

    PubMed

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

    2013-04-01

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

  11. A biodegradation study of forest biomass by Aspergillus niger F7: correlation between enzymatic activity, hydrolytic percentage and biodegradation index

    PubMed Central

    Sharma, Nivedita; Kaushal, Richa; Gupta, Rakesh; Kumar, Sanjeev

    2012-01-01

    Aspergillus niger F7 isolated from soil was found to be the potent producer of cellulase and xylanase. The residue of forest species Toona ciliata, Celtris australis, Cedrus deodara and Pinus roxburghii was selected as substrate for biodegradation study due to its easy availability and wide use in industry. It was subjected to alkali (sodium hydroxide) treatment for enhancing its degradation. Biodegradation of forest waste by hydrolytic enzymes (cellulase and xylanase) secreted by A. niger under solid state fermentation (SSF) was explored. SSF of pretreated forest biomass was found to be superior over untreated forest biomass. Highest extracellular enzyme activity of 2201±23.91 U/g by A. niger was shown in pretreated C. australis wood resulting in 6.72±0.20 percent hydrolysis and 6.99±0.23 biodegradation index (BI). The lowest BI of 1.40±0.08 was observed in untreated saw dust of C. deodara having the least enzyme activity of 238±1.36 U/g of dry matter. Biodegradation of forest biomass under SSF was increased many folds when moistening agent i.e. tap water had been replaced with modified basal salt media (BSM). In BSM mediated degradation of forest waste with A. niger, extracellular enzyme activity was increased up to 4089±67.11 U/g of dry matter in turn resulting in higher BI of 15.4±0.41 and percent hydrolysis of 19.38±0.81 in pretreated C. australis wood. A. niger exhibited higher enzyme activity on pretreated biomass when moistened with modified BSM in this study. Statistically a positive correlation has been drawn between these three factors i.e. enzyme activity, BI and percent hydrolysis of forest biomass thus proving their direct relationship with each other. PMID:24031853

  12. Optimal Atmospheric Correction for Above-Ground Forest Biomass Estimation with the ETM+ Remote Sensor.

    PubMed

    Nguyen, Hieu Cong; Jung, Jaehoon; Lee, Jungbin; Choi, Sung-Uk; Hong, Suk-Young; Heo, Joon

    2015-07-31

    The reflectance of the Earth's surface is significantly influenced by atmospheric conditions such as water vapor content and aerosols. Particularly, the absorption and scattering effects become stronger when the target features are non-bright objects, such as in aqueous or vegetated areas. For any remote-sensing approach, atmospheric correction is thus required to minimize those effects and to convert digital number (DN) values to surface reflectance. The main aim of this study was to test the three most popular atmospheric correction models, namely (1) Dark Object Subtraction (DOS); (2) Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) and (3) the Second Simulation of Satellite Signal in the Solar Spectrum (6S) and compare them with Top of Atmospheric (TOA) reflectance. By using the k-Nearest Neighbor (kNN) algorithm, a series of experiments were conducted for above-ground forest biomass (AGB) estimations of the Gongju and Sejong region of South Korea, in order to check the effectiveness of atmospheric correction methods for Landsat ETM+. Overall, in the forest biomass estimation, the 6S model showed the bestRMSE's, followed by FLAASH, DOS and TOA. In addition, a significant improvement of RMSE by 6S was found with images when the study site had higher total water vapor and temperature levels. Moreover, we also tested the sensitivity of the atmospheric correction methods to each of the Landsat ETM+ bands. The results confirmed that 6S dominates the other methods, especially in the infrared wavelengths covering the pivotal bands for forest applications. Finally, we suggest that the 6S model, integrating water vapor and aerosol optical depth derived from MODIS products, is better suited for AGB estimation based on optical remote-sensing data, especially when using satellite images acquired in the summer during full canopy development.

  13. Optimal Atmospheric Correction for Above-Ground Forest Biomass Estimation with the ETM+ Remote Sensor

    PubMed Central

    Nguyen, Hieu Cong; Jung, Jaehoon; Lee, Jungbin; Choi, Sung-Uk; Hong, Suk-Young; Heo, Joon

    2015-01-01

    The reflectance of the Earth’s surface is significantly influenced by atmospheric conditions such as water vapor content and aerosols. Particularly, the absorption and scattering effects become stronger when the target features are non-bright objects, such as in aqueous or vegetated areas. For any remote-sensing approach, atmospheric correction is thus required to minimize those effects and to convert digital number (DN) values to surface reflectance. The main aim of this study was to test the three most popular atmospheric correction models, namely (1) Dark Object Subtraction (DOS); (2) Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) and (3) the Second Simulation of Satellite Signal in the Solar Spectrum (6S) and compare them with Top of Atmospheric (TOA) reflectance. By using the k-Nearest Neighbor (kNN) algorithm, a series of experiments were conducted for above-ground forest biomass (AGB) estimations of the Gongju and Sejong region of South Korea, in order to check the effectiveness of atmospheric correction methods for Landsat ETM+. Overall, in the forest biomass estimation, the 6S model showed the bestRMSE’s, followed by FLAASH, DOS and TOA. In addition, a significant improvement of RMSE by 6S was found with images when the study site had higher total water vapor and temperature levels. Moreover, we also tested the sensitivity of the atmospheric correction methods to each of the Landsat ETM+ bands. The results confirmed that 6S dominates the other methods, especially in the infrared wavelengths covering the pivotal bands for forest applications. Finally, we suggest that the 6S model, integrating water vapor and aerosol optical depth derived from MODIS products, is better suited for AGB estimation based on optical remote-sensing data, especially when using satellite images acquired in the summer during full canopy development. PMID:26263996

  14. The dependence of synthetic aperture radar backscatter on forest structure and biomass: Potential application for global carbon models

    SciTech Connect

    Imhoff, M.L.

    1993-01-01

    The NASA airborne P-band (0.438 GHz), L-band (1.25 GHz), and C-band (5.3 GHz) quadpol. SAR system was used to collect data in tropical broadleaf evergreen forests on the Island of Hawaii.l The SAR data were regressed against biomass measurements made in the field and the response curves for the tropical forests were compared to those made for coniferous forests in North America and Europe using the same SAR instrument and imaging angles (40[degrees]-50[degrees]). Results indicated that the response curves for the tropical forests and the coniferous forests were similar and that the radar signals were saturating at relatively low biomass levels. Biomass saturation points were determined at [approx]100 tons/ha for P-band, [approx]40 tons/ha for L-band, and [approx]20 tons/has for C-band (HH, VV, and HV polarization). The possible existence of a universal saturation point for the SAR response to forest biomass distinctly limits the usefulness of P-, L-, and C-band SAR for global biomass mapping. A small percentage of the world's vegetated systems falls below the highest estimated saturation level. Approximately 46% of the world's vegetated surface area containing 82% of the estimated total store of biomass lies above the saturation limit of the current radar systems (>100 tons/ha for P-band). While 54% of the Earth's vegetated surfaces area is below the saturation level for P-band, this class contains only an estimated 18% of total biomass represented by terrestrial vegetation. Theoretical modeling indicated the primary forest canopy structural factor influencing SAR backscatter was the surface area to volume ratio (SA/V) of the branches. This proved true for both broadleaf evergreens and conifers. As a forest stand matures, the form of the phytomass coalesces into fewer larger components and the calculated SA/V declines as biomass increases. As the SA/V declines the backscatter trends to increase since the radar has larger components from which reflections can occur.

  15. 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.

  16. From plot to province; scaling field mensuration to stand-level lidar to public GIS data in a hierarchical approach to map regional forest biomass

    NASA Astrophysics Data System (ADS)

    Hopkinson, C.; Colville, D.; Bourdeau, D.; Monette, S.; Fox, A.; Maher, R.

    2010-12-01

    As public energy utilities rise to the dual challenge of meeting growing energy demands while attempting to reduce greenhouse gas emissions, there is a clear and urgent need to inventory any ‘green’ energies that are potentially available for energy generation. In heavily forest-covered landscapes such as in the Province of Nova Scotia, forest bio-fuels potentially offer a viable source of carbon-neutral alternative energy that can be exploited with relatively minor modification of existing power generation infrastructure. However, while government GIS databases do contain extensive stand-level forest resource inventory (FRI) data covering the entire Province, the conversion of these data into meaningful estimates of available and sustainable biofuel requires calibration. At the opposite end of the scale, permanent sample plot (PSP) data collected in the field allows accurate calculation of biomass over very small areas but scaling between PSPs and FRI stands is challenged by the large within-stand heterogeneity displayed by Acadian mixed wood forests. Airborne Lidar rapidly samples the 3D structure of forest canopies over large areas at high resolutions and thus offers the perfect opportunity to scale between PSP and FRI data. In this study, approximately 100 PSPs visited within two years of a geographically coincident lidar survey between the years 2005 and 2010, were selected to train a lidar-based model of biomass, which was then used to train an FRI-based model which could be applied to the entire Province. PSP data (species, height, diameter at breast height and stem density) were used to directly quantify green, dry, woody and foliage biomass. Lidar data collected over approximately 30 different survey missions using the same airborne laser terrain mapper (ALTM) 3100 sensor were extracted for each of the PSPS. Summary statistics describing the within-plot vertical lidar frequency distributions were combined with physical lidar intensity and echo

  17. Forest biomass density across large climate gradients in northern South America is related to water availability but not with temperature.

    PubMed

    Álvarez-Dávila, Esteban; Cayuela, Luis; González-Caro, Sebastián; Aldana, Ana M; Stevenson, Pablo R; Phillips, Oliver; Cogollo, Álvaro; Peñuela, Maria C; von Hildebrand, Patricio; Jiménez, Eliana; Melo, Omar; Londoño-Vega, Ana Catalina; Mendoza, Irina; Velásquez, Oswaldo; Fernández, Fernando; Serna, Marcela; Velázquez-Rua, Cesar; Benítez, Doris; Rey-Benayas, José M

    2017-01-01

    Understanding and predicting the likely response of ecosystems to climate change are crucial challenges for ecology and for conservation biology. Nowhere is this challenge greater than in the tropics as these forests store more than half the total atmospheric carbon stock in their biomass. Biomass is determined by the balance between biomass inputs (i.e., growth) and outputs (mortality). We can expect therefore that conditions that favor high growth rates, such as abundant water supply, warmth, and nutrient-rich soils will tend to correlate with high biomass stocks. Our main objective is to describe the patterns of above ground biomass (AGB) stocks across major tropical forests across climatic gradients in Northwestern South America. We gathered data from 200 plots across the region, at elevations ranging between 0 to 3400 m. We estimated AGB based on allometric equations and values for stem density, basal area, and wood density weighted by basal area at the plot-level. We used two groups of climatic variables, namely mean annual temperature and actual evapotranspiration as surrogates of environmental energy, and annual precipitation, precipitation seasonality, and water availability as surrogates of water availability. We found that AGB is more closely related to water availability variables than to energy variables. In northwest South America, water availability influences carbon stocks principally by determining stand structure, i.e. basal area. When water deficits increase in tropical forests we can expect negative impact on biomass and hence carbon storage.

  18. Forest biomass density across large climate gradients in northern South America is related to water availability but not with temperature

    PubMed Central

    Cayuela, Luis; González-Caro, Sebastián; Aldana, Ana M.; Stevenson, Pablo R.; Phillips, Oliver; Cogollo, Álvaro; Peñuela, Maria C.; von Hildebrand, Patricio; Jiménez, Eliana; Melo, Omar; Londoño-Vega, Ana Catalina; Mendoza, Irina; Velásquez, Oswaldo; Fernández, Fernando; Serna, Marcela; Velázquez-Rua, Cesar; Benítez, Doris; Rey-Benayas, José M.

    2017-01-01

    Understanding and predicting the likely response of ecosystems to climate change are crucial challenges for ecology and for conservation biology. Nowhere is this challenge greater than in the tropics as these forests store more than half the total atmospheric carbon stock in their biomass. Biomass is determined by the balance between biomass inputs (i.e., growth) and outputs (mortality). We can expect therefore that conditions that favor high growth rates, such as abundant water supply, warmth, and nutrient-rich soils will tend to correlate with high biomass stocks. Our main objective is to describe the patterns of above ground biomass (AGB) stocks across major tropical forests across climatic gradients in Northwestern South America. We gathered data from 200 plots across the region, at elevations ranging between 0 to 3400 m. We estimated AGB based on allometric equations and values for stem density, basal area, and wood density weighted by basal area at the plot-level. We used two groups of climatic variables, namely mean annual temperature and actual evapotranspiration as surrogates of environmental energy, and annual precipitation, precipitation seasonality, and water availability as surrogates of water availability. We found that AGB is more closely related to water availability variables than to energy variables. In northwest South America, water availability influences carbon stocks principally by determining stand structure, i.e. basal area. When water deficits increase in tropical forests we can expect negative impact on biomass and hence carbon storage. PMID:28301482

  19. Estimation of aboveground woody biomass using HJ-1 and Radarsat-2 data for deciduous forests in Daxing'anling, China

    NASA Astrophysics Data System (ADS)

    Liu, Qian; Yang, Le; Liu, Qinhuo; Li, Jing

    2014-11-01

    Accurate estimation of forest aboveground biomass is important for global carbon budgets and ecosystem change studies. Most algorithms for regional or global aboveground biomass estimation using optical and microwave remote sensing data are based on empirical regression and non-parametric training methods, which require large amount of ground measurements for training and are lacking of explicit interaction mechanisms between electromagnetic wave and vegetation. In this study, we proposed an optical/microwave synergy method based on a coherent polarimetric SAR model to estimate woody biomass. The study area is sparse deciduous forest dominated by birch with understory of shrubs and herbs in Daxing'anling, China. HJ-1, Radarsat-2 images, and field LAI were collected during May to August in 2013, tree biophysical parameters were measured at the field campaign during August to September in 2012. The effects of understory and wet ground were evaluated by introducing the NDVI derived from HJ-1 image and rain rate. Field measured LAI was used as an input to the SAR model to define the scattering and attenuation of the green canopy to the total backscatter. Finally, an logarithmic equation between the backscatter coefficient of direct forest scattering mechanism and woody biomass was generated (R2=0.582). The retrieval results were validated with the ground biomass measurements (RMSE=29.01ton/ha). The results indicated the synergy of optical and microwave remote sensing data based on SAR model has the potential to improve the accuracy of woody biomass estimation.

  20. Determination of continuous intermediate scale soil moisture, biomass water content and interception using the cosmic-ray neutron intensity method

    NASA Astrophysics Data System (ADS)

    Andreasen, M.; Looms, M. C.; Bogena, H. R.; Sonnenborg, T.; Jensen, K.

    2013-12-01

    and the moss layer of a forested site. In the beginning of 2013 five cosmic-ray neutron probes were installed in the Ahlergaarde catchment at sites representing the two major land uses (agriculture (61 %) and forest (17 %)). The standard installation procedure is to place the probes at 1.5 m above the ground. Here, probes detecting neutron intensity at different energies (0.025 eV and 0.5 - 106 eV) were installed at different heights above the surface. Probes at surface level were used for the detection of soil moisture, whereas the difference in the count rates at the different energy levels and heights above the surface were used to investigate the biomass-water and the intercepted water fluxes. In this study continuous measurements of intermediate scale soil moisture were carried out at the two sites, and the potential of using the cosmic-ray neutron method to determine the water content of the biomass and the interception storage were tested.

  1. The summertime Boreal forest field measurement intensive (HUMPPA-COPEC-2010): an overview of meteorological and chemical influences

    NASA Astrophysics Data System (ADS)

    Williams, J.; Crowley, J.; Fischer, H.; Harder, H.; Martinez, M.; Petäjä, T.; Rinne, J.; Bäck, J.; Boy, M.; Dal Maso, M.; Hakala, J.; Kajos, M.; Keronen, P.; Rantala, P.; Aalto, J.; Aaltonen, H.; Paatero, J.; Vesala, T.; Hakola, H.; Levula, J.; Pohja, T.; Herrmann, F.; Auld, J.; Mesarchaki, E.; Song, W.; Yassaa, N.; Nölscher, A.; Johnson, A. M.; Custer, T.; Sinha, V.; Thieser, J.; Pouvesle, N.; Taraborrelli, D.; Tang, M. J.; Bozem, H.; Hosaynali-Beygi, Z.; Axinte, R.; Oswald, R.; Novelli, A.; Kubistin, D.; Hens, K.; Javed, U.; Trawny, K.; Breitenberger, C.; Hidalgo, P. J.; Ebben, C. J.; Geiger, F. M.; Corrigan, A. L.; Russell, L. M.; Ouwersloot, H.; Vilà-Guerau de Arellano, J.; Ganzeveld, L.; Vogel, A.; Beck, M.; Bayerle, A.; Kampf, C. J.; Bertelmann, M.; Köllner, F.; Hoffmann, T.; Valverde, J.; González, D.; Riekkola, M.-L.; Kulmala, M.; Lelieveld, J.

    2011-05-01

    This paper describes the background, instrumentation, goals, and the regional influences on the HUMPPA-COPEC intensive field measurement campaign, conducted at the Boreal forest research station SMEAR II (Station for Measuring Ecosystem-Atmosphere Relation) in Hyytiälä, Finland from 12 July-12 August 2010. The prevailing meteorological conditions during the campaign are examined and contrasted with those of the past six years. Back trajectory analyses show that meteorological conditions at the site were characterized by a higher proportion of southerly flow. As a result the summer of 2010 was anomalously warm and high in ozone making the campaign relevant for the analysis of possible future climates. A comprehensive land use analysis, provided on both 5 and 50 km scales, shows that the main vegetation types surrounding the site on both the regional and local scales are: coniferous forest (Scots pine and/or Norway spruce); mixed forest (Birch and conifers); and woodland scrub (e.g. Willows, Aspen); indicating that the campaign results can be taken as representative of the Boreal forest ecosystem. In addition to the influence of biogenic emissions, the measurement site was occasionally impacted by sources other than vegetation. Specific tracers have been used here to identify the time periods when such sources have impacted the site namely: biomass burning (acetonitrile and CO), urban anthropogenic pollution (pentane and SO2) and the nearby Korkeakoski sawmill (enantiomeric ratio of chiral monoterpenes). None of these sources dominated the study period, allowing the Boreal forest summertime emissions to be assessed and contrasted with various other source signatures.

  2. The summertime Boreal forest field measurement intensive (HUMPPA-COPEC-2010): an overview of meteorological and chemical influences

    NASA Astrophysics Data System (ADS)

    Williams, J.; Crowley, J.; Fischer, H.; Harder, H.; Martinez, M.; Petäjä, T.; Rinne, J.; Bäck, J.; Boy, M.; Dal Maso, M.; Hakala, J.; Kajos, M.; Keronen, P.; Rantala, P.; Aalto, J.; Aaltonen, H.; Paatero, J.; Vesala, T.; Hakola, H.; Levula, J.; Pohja, T.; Herrmann, F.; Auld, J.; Mesarchaki, E.; Song, W.; Yassaa, N.; Nölscher, A.; Johnson, A. M.; Custer, T.; Sinha, V.; Thieser, J.; Pouvesle, N.; Taraborrelli, D.; Tang, M. J.; Bozem, H.; Hosaynali-Beygi, Z.; Axinte, R.; Oswald, R.; Novelli, A.; Kubistin, D.; Hens, K.; Javed, U.; Trawny, K.; Breitenberger, C.; Hidalgo, P. J.; Ebben, C. J.; Geiger, F. M.; Corrigan, A. L.; Russell, L. M.; Ouwersloot, H. G.; Vilà-Guerau de Arellano, J.; Ganzeveld, L.; Vogel, A.; Beck, M.; Bayerle, A.; Kampf, C. J.; Bertelmann, M.; Köllner, F.; Hoffmann, T.; Valverde, J.; González, D.; Riekkola, M.-L.; Kulmala, M.; Lelieveld, J.

    2011-10-01

    This paper describes the background, instrumentation, goals, and the regional influences on the HUMPPA-COPEC intensive field measurement campaign, conducted at the Boreal forest research station SMEAR II (Station for Measuring Ecosystem-Atmosphere Relation) in Hyytiälä, Finland from 12 July-12 August 2010. The prevailing meteorological conditions during the campaign are examined and contrasted with those of the past six years. Back trajectory analyses show that meteorological conditions at the site in 2010 were characterized by a higher proportion of southerly flow than in the other years studied. As a result the summer of 2010 was anomalously warm and high in ozone making the campaign relevant for the analysis of possible future climates. A comprehensive land use analysis, provided on both 5 and 50 km scales, shows that the main vegetation types surrounding the site on both the regional and local scales are: coniferous forest (Scots pine and/or Norway spruce); mixed forest (Birch and conifers); and woodland scrub (e.g. Willows, Aspen); indicating that the campaign results can be taken as representative of the Boreal forest ecosystem. In addition to the influence of biogenic emissions, the measurement site was occasionally impacted by sources other than vegetation. Specific tracers have been used here to identify the time periods when such sources have impacted the site namely: biomass burning (acetonitrile and CO), urban anthropogenic pollution (pentane and SO2) and the nearby Korkeakoski sawmill (enantiomeric ratio of chiral monoterpenes). None of these sources dominated the study period, allowing the Boreal forest summertime emissions to be assessed and contrasted with various other source signatures.

  3. The summertime Boreal forest field measurement intensive (HUMPPA-COPEC-2010): an overview of meteorological and chemical influences.

    NASA Astrophysics Data System (ADS)

    Williams, J.; Petäjä, T.

    2012-04-01

    This submission describes the background, instrumentation, goals, and the regional influences on the HUMPPA-COPEC intensive field measurement campaign, conducted at the Boreal forest research station SMEAR II (Station for Measuring Ecosystem-Atmosphere Relation) in Hyytiälä, Finland from 12th July-12th August 2010. The prevailing meteorological conditions during the campaign are examined and contrasted with those of the past six years. Back trajectory analyses show that meteorological conditions at the site in 2010 were characterized by a higher proportion of southerly flow than in the other years studied. As a result the summer of 2010 was anomalously warm and high in ozone making the campaign relevant for the analysis of possible future climates. A comprehensive land use analysis, provided on both 5 and 50 km scales, shows that the main vegetation types surrounding the site on both the regional and local scales are: coniferous forest (Scots pine and/or Norway spruce); mixed forest (Birch and conifers); and woodland scrub (e.g. Willows, Aspen); indicating that the campaign results can be taken as representative of the Boreal forest ecosystem. In addition to the influence of biogenic emissions, the measurement site was occasionally impacted by sources other than vegetation. Specific tracers have been used here to identify the time periods when such sources have impacted the site namely: biomass burning (acetonitrile and CO), urban anthropogenic pollution (pentane and SO2) and the nearby Korkeakoski sawmill (enantiomeric ratio of chiral monoterpenes). None of these sources dominated the study period, allowing the Boreal forest summertime emissions to be assessed and contrasted with various other source signatures.

  4. Simulation results of aboveground woody biomass and leaf litterfall for African tropical forest with a global terrestrial model

    NASA Astrophysics Data System (ADS)

    De Weirdt, Marjolein; Maignan, Fabienne; Peylin, Philippe; Poulter, Benjamin; Moreau, Inès; Ciais, Philippe; Defourny, Pierre; Steppe, Kathy; Verbeeck, Hans

    2014-05-01

    The response of tropical forest vegetation to global climate change could be central to predictions of future levels of atmospheric carbon dioxide. Tropical forests are believed to annually process approximately six times as much carbon via photosynthesis and respiration as humans emit from fossil fuel use. Of all tropical forests worldwide, the role of African tropical forest is not very well known and both the quantity as well as the dynamics of tropical forest carbon stocks and fluxes are very poorly quantified components of the global carbon cycle. Furthermore, African tropical forest spatial carbon stocks patterns as measured in the field are not as well represented by the global biogeochemical models as they are for temperate forests. In this study, a first simulation for the African tropical forest with the process based global terrestrial ecosystem model ORCHIDEE was done. In this work, ORCHIDEE included deep soils, seasonal leaf litterfall and phosphorus availability mechanisms for tropical evergreen forests included. The ORCHIDEE model run outputs are evaluated against reported field inventories, investigating seasonal variations in leaf litterfall and spatial variation in aboveground woody biomass. A comparison between modeled and measured leaf litterfall was made at a semi-deciduous Equatorial rainforest site in the Republic of Congo at the Biosphere reserve Dimonika south of Gabon. Also, simulated woody aboveground biomass was compared against site-level field inventories and satellite-based estimates based on a combination of MODIS imagery with field inventory data from Uganda, DRC and Cameroon. First comparison results seem promising and show that the radiation driven leaf litterfall model results correspond well with the field inventories and that the mean of the modelled aboveground woody biomass matches the available field inventory observations but there is still a need for more ground data to evaluate the model outcome over a large region like

  5. Estimating Forest Aboveground Biomass by Combining Optical and SAR Data: A Case Study in Genhe, Inner Mongolia, China

    PubMed Central

    Shao, Zhenfeng; Zhang, Linjing

    2016-01-01

    Estimation of forest aboveground biomass is critical for regional carbon policies and sustainable forest management. Passive optical remote sensing and active microwave remote sensing both play an important role in the monitoring of forest biomass. However, optical spectral reflectance is saturated in relatively dense vegetation areas, and microwave backscattering is significantly influenced by the underlying soil when the vegetation coverage is low. Both of these conditions decrease the estimation accuracy of forest biomass. A new optical and microwave integrated vegetation index (VI) was proposed based on observations from both field experiments and satellite (Landsat 8 Operational Land Imager (OLI) and RADARSAT-2) data. According to the difference in interaction between the multispectral reflectance and microwave backscattering signatures with biomass, the combined VI (COVI) was designed using the weighted optical optimized soil-adjusted vegetation index (OSAVI) and microwave horizontally transmitted and vertically received signal (HV) to overcome the disadvantages of both data types. The performance of the COVI was evaluated by comparison with those of the sole optical data, Synthetic Aperture Radar (SAR) data, and the simple combination of independent optical and SAR variables. The most accurate performance was obtained by the models based on the COVI and optical and microwave optimal variables excluding OSAVI and HV, in combination with a random forest algorithm and the largest number of reference samples. The results also revealed that the predictive accuracy depended highly on the statistical method and the number of sample units. The validation indicated that this integrated method of determining the new VI is a good synergistic way to combine both optical and microwave information for the accurate estimation of forest biomass. PMID:27338378

  6. Quantifying variation in forest disturbance, and its effects on aboveground biomass dynamics, across the eastern United States.

    PubMed

    Vanderwel, Mark C; Coomes, David A; Purves, Drew W

    2013-05-01

    The role of tree mortality in the global carbon balance is complicated by strong spatial and temporal heterogeneity that arises from the stochastic nature of carbon loss through disturbance. Characterizing spatio-temporal variation in mortality (including disturbance) and its effects on forest and carbon dynamics is thus essential to understanding the current global forest carbon sink, and to predicting how it will change in future. We analyzed forest inventory data from the eastern United States to estimate plot-level variation in mortality (relative to a long-term background rate for individual trees) for nine distinct forest regions. Disturbances that produced at least a fourfold increase in tree mortality over an approximately 5 year interval were observed in 1-5% of plots in each forest region. The frequency of disturbance was lowest in the northeast, and increased southwards along the Atlantic and Gulf coasts as fire and hurricane disturbances became progressively more common. Across the central and northern parts of the region, natural disturbances appeared to reflect a diffuse combination of wind, insects, disease, and ice storms. By linking estimated covariation in tree growth and mortality over time with a data-constrained forest dynamics model, we simulated the implications of stochastic variation in mortality for long-term aboveground biomass changes across the eastern United States. A geographic gradient in disturbance frequency induced notable differences in biomass dynamics between the least- and most-disturbed regions, with variation in mortality causing the latter to undergo considerably stronger fluctuations in aboveground stand biomass over time. Moreover, regional simulations showed that a given long-term increase in mean mortality rates would support greater aboveground biomass when expressed through disturbance effects compared with background mortality, particularly for early-successional species. The effects of increased tree mortality on

  7. Canopy Vertical Spatial Scales which Constrain Biomass in a Tropical Forest at the Plot Level: Unifying Lidar and InSAR for Biomass Estimation

    NASA Astrophysics Data System (ADS)

    Treuhaft, R. N.; Goncalves, F. G.; Drake, J. B.; Chapman, B. D.; Dos Santos, J. R.; Dutra, L. V.; Graca, P. M.; Purcell, G. H.

    2009-12-01

    Structural remote sensing of forest biomass, using lidar and/or interferometric synthetic aperture radar (InSAR), often involves regressing field measured biomass against remotely sensed characteristics of the vertical density profile. Because spaceborne lidar or InSAR sensors will estimate structural characteristics averaged at the plot level (0.04-1 hectare), and because tropical forests contain 40% of the Earth’s forested biomass, this study focuses on the scales of vertical characteristics which best correlate with tropical forest biomass. This work suggests that the structural characteristics used in both lidar and InSAR biomass estimation, such as mean height or total height or height of median energy, are based on the behavior of Fourier vertical frequency components of vegetation density near zero frequency; that is, they are very low-spatial frequency characteristics of the vertical vegetation distribution. In this work, we ask which other vertical Fourier frequencies in lidar- or InSAR-produced structure metrics can best correlate with field biomass. Using lidar (LVIS) data from La Selva Biological Station, Costa Rica, taken in 2005, lidar canopy observations are Fourier transformed in the vertical direction to decompose into vertical frequency components. Each baseline of an InSAR observation, the complex coherence, is this Fourier transform of the canopy, if the ground contribution can be neglected. Using the qualitative similarity in vertical profiles seen by lidar, InSAR (at C-band, from AirSAR in 2004), and field measurements in the La Selva data, we produce the equivalent many (1000’s of) InSAR baselines from the lidar data and, using the lidar-simulated InSAR, determine the optimal spatial frequencies—baselines at DESDynI orbital altitudes for InSAR—which would estimate biomass in this wet tropical forest most accurately for either technique. For biomass ranging from 39-490 Mg/ha, regressing field biomass against some function of height

  8. Canopy Biomass Lidar (CBL) Acquisitions at NEON and TERN Forest Sites

    NASA Astrophysics Data System (ADS)

    Schaaf, C.; Paynter, I.; Saenz, E.; Peri, F.; Wang, Z.; Erb, A.; Yang, X.; Strahler, A. H.; Li, Z.; van Aardt, J. A.; Kelbe, D.; Romanczyk, P.; Cawse-Nicholson, K.; Krause, K.; Leisso, N.; Kampe, T. U.; Meier, C. L.; Ritz, C.; Chakrabarti, S.; Cook, T.; Howe, G.; Martel, J.; Hewawasam, K.; Douglas, E. S.; Newnham, G.; Schaefer, M.; Armston, J.; Muir, J.; Tindall, D.; Phinn, S. R.

    2013-12-01

    Terrestrial Laser Scanning (TLS) offers the ability to capture complex forest structure through 3D reconstruction of multiple laser return point clouds. These reconstructions provide detailed information on understory, mid-story and canopy structure and allow quantification of important ecosystem factors such as biomass, vegetation productivity, forest health and response to disturbance. Used in conjunction with airborne lidar and satellite imaging, TLS is a powerful calibration/validation tool for improved regional scale ecological surveying and modeling. Repeated deployments facilitate the estimation of growth rates, nutrient fluxes, and other essential parameters in global scale climate and biogeochemic modeling. Routine TLS acquisitions at long-term research sites provide an opportunity to capture temporal variations due to natural and anthropogenic effects. While discrete return and full waveform TLS instruments (such as the Dual Wavelength Echidna Lidar (DWEL)) are increasingly being deployed, there is also a need for high speed, low-cost, highly portable TLS instruments to augment these more powerful, high resolution lidars. The Canopy Biomass Lidar (CBL) is a light, fast-scanning, time-of-flight, 905nm, TLS instrument, conceived by the Katholieke Universiteit Leuven (KUL) and refined by the Rochester Institute of Technology (RIT). Two CBLs, constructed by the University of Massachusetts Boston, were deployed alongside the full waveform DWEL (developed by Boston University, University of Massachusetts Lowell, University of Massachusetts Boston, and the Commonwealth Scientific and Industrial Research Organisation (CSIRO)) during the June 2013 NEON Airborne Observation Platform (AOP) campaign in the Sierra National Forest, CA. Three sites were characterized by both the CBLs and the DWEL in the Soaproot and Teakettle regions (where relocatable NEON towers will be situated). Up to 5 multiple scans were acquired by the DWEL, with an additional 8-12 scans obtained

  9. Influence of windthrows and tree species on forest soil plant biomass and carbon stocks

    NASA Astrophysics Data System (ADS)

    Veselinovic, B.; Hager, H.

    2012-04-01

    The role of forests has generally been recognized in climate change mitigation and adaptation strategies and policies (e.g. Kyoto Protocol within articles 3.3 and 3.4, RES-E Directive of EU, Country Biomass Action Plans etc.). Application of mitigation actions, to decrease of CO2-emissions and, as the increase of carbon(C)-stocks and appropriate GHG-accounting has been hampered due to a lack of reliable data and good statistical models for the factors influencing C-sequestration in and its release from these systems (e.g. natural and human induced disturbances). Highest uncertainties are still present for estimation of soil C-stocks, which is at the same time the second biggest C-reservoir on earth. Spruce monocultures have been a widely used management practice in central Europe during the past century. Such stands are in lower altitudes (e.g. submontane to lower montane elevation zone) and on heavy soils unstable and prone to disturbances, especially on blowdown. As the windthrow-areas act as CO2-source, we hypothesize that conversion to natural beech and oak forests will provide sustainable wood supply and higher stability of stands against blowdown, which simultaneously provides the long-term belowground C-sequestration. This work focuses on influence of Norway spruce, Common beech and Oak stands on belowground C-dynamics (mineral soil, humus and belowground biomass) taking into consideration the increased impact of windthrows on spruce monocultures as a result of climate change. For this purpose the 300-700m altitude and pseudogley (planosols/temporally logged) soils were chosen in order to evaluate long-term impacts of the observed tree species on belowground C-dynamics and human induced disturbances on secondary spruce stands. Using the false chronosequence approach, the C-pools have been estimated for different compartments and age classes. The sampling of forest floor and surface vegetation was done using 30x30 (homogenous plots) and 50x50cm (inhomogeneous

  10. Estimation of Biomass Carbon Stocks over Peat Swamp Forests using Multi-Temporal and Multi-Polratizations SAR Data

    NASA Astrophysics Data System (ADS)

    Wijaya, A.; Liesenberg, V.; Susanti, A.; Karyanto, O.; Verchot, L. V.

    2015-04-01

    The capability of L-band radar backscatter to penetrate through the forest canopy is useful for mapping the forest structure, including above ground biomass (AGB) estimation. Recent studies confirmed that the empirical AGB models generated from the L-band radar backscatter can provide favourable estimation results, especially if the data has dual-polarization configuration. Using dual polarimetry SAR data the backscatter signal is more sensitive to forest biomass and forest structure because of tree trunk scattering, thus showing better discriminations of different forest successional stages. These SAR approaches, however, need to be further studied for the application in tropical peatlands ecosystem We aims at estimating forest carbon stocks and stand biophysical properties using combination of multi-temporal and multi-polarizations (quad-polarimetric) L-band SAR data and focuses on tropical peat swamp forest over Kampar Peninsula at Riau Province, Sumatra, Indonesia which is one of the most peat abundant region in the country. Applying radar backscattering (Sigma nought) to model the biomass we found that co-polarizations (HH and VV) band are more sensitive than cross-polarization channels (HV and VH). Individual HH polarization channel from April 2010 explained > 86% of AGB. Whereas VV polarization showed strong correlation coefficients with LAI, tree height, tree diameter and basal area. Surprisingly, polarimetric anisotropy feature from April 2007 SAR data show relatively high correlations with almost all forest biophysical parameters. Polarimetric anisotropy, which explains the ratio between the second and the first dominant scattering mechanism from a target has reduced at some extent the randomness of scattering mechanism, thus improve the predictability of this particular feature in estimating the forest properties. These results may be influenced by local seasonal variations of the forest as well as moisture, but available quad-pol SAR data were unable to

  11. The influence of abiotic controls and management intensity on phosphorus cycling in established grassland and forest ecosystems

    NASA Astrophysics Data System (ADS)

    Alt, F.; Oelmann, Y.; Wilcke, W.

    2011-12-01

    It is commonly assumed that the bioavailability and cycling of phosphorus (P) is mainly controlled by abiotic soil properties including soil pH and the concentrations and reactivities of clay minerals, CaCO3 and Al/Fe oxides In managed ecosystems, kind, timing and duration of P additions and type and amount of harvested biomass are the major input and output fluxes. Our objective was to disentangle the effects of abiotic controls, and type and intensity of management on the P cycle in soils of temperate grasslands and forests of different management intensity in three regions across Germany in the frame of the Biodiversity Exploratories project. The pH value was the most important variable explaining P concentrations and partitioning in soil and changes in pH are the main mechanism how land-use is affecting the P cycle. However, after the influence of pH was accounted for in a sequential statistical approach, land-use intensity, classified according to the extent of annual biomass removal, explained a significant (P < 0.05) part of the variance in the contributions of several P fractions to total P (TP) among all studied regions and land-use types. In grassland soils of highly diverse systems (up to 57 plant species) in one of the study regions, the Schwäbische Alb, a mid-range mountain area on limestone where soils showed a limited variation in pH in the carbonate buffer range, pedogenic Fe oxide concentrations, fertilizer-P application rates, and TP concentrations in soil explained more than half of the variation in bioavailable inorganic (Pi) concentrations extracted with NaHCO3 in soil. Our results demonstrate that mainly soil pH and mineralogical composition, and intensity of management of the managed ecosystems are significant controls of the P cycle determining the size of bioavailable P pool in soil.

  12. Atmospheric Emissions from Forest Biomass Residues to Energy Supply Chain: A Case Study in Portugal

    PubMed Central

    Rafael, Sandra; Tarelho, Luis; Monteiro, Alexandra; Monteiro, Tânia; Gonçalves, Catarina; Freitas, Sylvio; Lopes, Myriam

    2015-01-01

    Abstract During the past decades, pressures on global environment and energy security have led to an increasing demand on renewable energy sources and diversification of the world's energy supply. The Portuguese energy strategy considers the use of Forest Biomass Residues (FBR) to energy as being essential to accomplish the goals established in the National Energy Strategy for 2020. However, despite the advantages pointing to FBR to the energy supply chain, few studies have evaluated the potential impacts on air quality. In this context, a case study was selected to estimate the atmospheric emissions of the FBR to the energy supply chain in Portugal. Results revealed that production, harvesting, and energy conversion processes are the main culprits for the biomass energy supply chain emissions (with a contribution higher than 90%), while the transport processes have a minor importance for all the pollutants. Compared with the coal-fired plants, the FBR combustion produces lower greenhouses emissions, on a mass basis of fuel consumed; the same is true for NOX and SO2 emissions. PMID:26064039

  13. Atmospheric Emissions from Forest Biomass Residues to Energy Supply Chain: A Case Study in Portugal.

    PubMed

    Rafael, Sandra; Tarelho, Luis; Monteiro, Alexandra; Monteiro, Tânia; Gonçalves, Catarina; Freitas, Sylvio; Lopes, Myriam

    2015-06-01

    During the past decades, pressures on global environment and energy security have led to an increasing demand on renewable energy sources and diversification of the world's energy supply. The Portuguese energy strategy considers the use of Forest Biomass Residues (FBR) to energy as being essential to accomplish the goals established in the National Energy Strategy for 2020. However, despite the advantages pointing to FBR to the energy supply chain, few studies have evaluated the potential impacts on air quality. In this context, a case study was selected to estimate the atmospheric emissions of the FBR to the energy supply chain in Portugal. Results revealed that production, harvesting, and energy conversion processes are the main culprits for the biomass energy supply chain emissions (with a contribution higher than 90%), while the transport processes have a minor importance for all the pollutants. Compared with the coal-fired plants, the FBR combustion produces lower greenhouses emissions, on a mass basis of fuel consumed; the same is true for NOX and SO2 emissions.

  14. Winter climate change affects growing-season soil microbial biomass and activity in northern hardwood forests.

    PubMed

    Durán, Jorge; Morse, Jennifer L; Groffman, Peter M; Campbell, John L; Christenson, Lynn M; Driscoll, Charles T; Fahey, Timothy J; Fisk, Melany C; Mitchell, Myron J; Templer, Pamela H

    2014-11-01

    Understanding the responses of terrestrial ecosystems to global change remains a major challenge of ecological research. We exploited a natural elevation gradient in a northern hardwood forest to determine how reductions in snow accumulation, expected with climate change, directly affect dynamics of soil winter frost, and indirectly soil microbial biomass and activity during the growing season. Soils from lower elevation plots, which accumulated less snow and experienced more soil temperature variability during the winter (and likely more freeze/thaw events), had less extractable inorganic nitrogen (N), lower rates of microbial N production via potential net N mineralization and nitrification, and higher potential microbial respiration during the growing season. Potential nitrate production rates during the growing season were particularly sensitive to changes in winter snow pack accumulation and winter soil temperature variability, especially in spring. Effects of elevation and winter conditions on N transformation rates differed from those on potential microbial respiration, suggesting that N-related processes might respond differently to winter climate change in northern hardwood forests than C-related processes.

  15. Development of economic and environmental metrics for forest-based biomass harvesting

    NASA Astrophysics Data System (ADS)

    Zhang, F. L.; Wang, J. J.; Liu, S. H.; Zhang, S. M.

    2016-08-01

    An assessment of the economic, energy consumption, and greenhouse gas (GHG) emission dimensions of forest-based biomass harvest stage in the state of Michigan, U.S. through gathering data from literature, database, and other relevant sources, was performed. The assessment differentiates harvesting systems (cut-to-length harvesting, whole tree harvesting, and motor-manual harvesting), harvest types (30%, 70%, and 100% cut) and forest types (hardwoods, softwoods, mixed hardwood/softwood, and softwood plantations) that characterize Michigan's logging industry. Machine rate methods were employed to determine unit harvesting cost. A life cycle inventory was applied to calculating energy demand and GHG emissions of different harvesting scenarios, considering energy and material inputs (diesel, machinery, etc.) and outputs (emissions) for each process (cutting, forwarding/skidding, etc.). A sensitivity analysis was performed for selected input variables for the harvesting operation in order to explore their relative importance. The results indicated that productivity had the largest impact on harvesting cost followed by machinery purchase price, yearly scheduled hours, and expected utilization. Productivity and fuel use, as well as fuel factors, are the most influential environmental impacts of harvesting operations.

  16. Tropical Forest Vegetation Profiles and Biomass from Multibaseline Interferometric SAR at C- band

    NASA Astrophysics Data System (ADS)

    Treuhaft, R.; Chapman, B.; Santos, J. R.; Dutra, L.; Goncalves, F.; Graca, P. A.; Drake, J.

    2007-12-01

    Interferometric synthetic aperture radar (InSAR) involves the reception of SAR signals at two spatially separated ends of a baseline. The resulting phase and coherence observations from InSAR are both sensitive to the vertical structure of vegetation. However, multiple InSAR observations--more than one phase-coherence-pair--are needed to estimate parameters describing vertical structure. Multiple observations can be made with different baselines, polarizations, or frequencies. This talk reviews why InSAR is sensitive to vertical structure. It then describes an experiment in the tropical forests of La Selva Biological Station in Costa Rica in which 12-14 baselines were used to estimate vegetation vertical profiles at C-band. Calibration of the InSAR phases and coherences with nearby pastures was essential for interpreting the data for vegetation, rather than surface, characteristics. Relative density profiles from primary, secondary, and selectively logged forests will be shown along with profiles from abandoned pastures. Field methods used to validate the profiles involve measuring individual tree dimensions, and the production of field profiles will be described and compared to InSAR profiles. Lidar profiles will also be shown for comparison. Functions of the InSAR profiles will be used estimate biomass of 30 stands

  17. Recent acceleration of biomass burning and carbon losses in Alaskan forests and peatlands

    USGS Publications Warehouse

    Turetsky, M.R.; Kane, E.S.; Harden, J.W.; Ottmar, R.D.; Manies, K.L.; Hoy, E.; Kasischke, E.S.

    2011-01-01

    Climate change has increased the area affected by forest fires each year in boreal North America. Increases in burned area and fire frequency are expected to stimulate boreal carbon losses. However, the impact of wildfires on carbon emissions is also affected by the severity of burning. How climate change influences the severity of biomass burning has proved difficult to assess. Here, we examined the depth of ground-layer combustion in 178 sites dominated by black spruce in Alaska, using data collected from 31 fire events between 1983 and 2005. We show that the depth of burning increased as the fire season progressed when the annual area burned was small. However, deep burning occurred throughout the fire season when the annual area burned was large. Depth of burning increased late in the fire season in upland forests, but not in peatland and permafrost sites. Simulations of wildfire-induced carbon losses from Alaskan black spruce stands over the past 60 years suggest that ground-layer combustion has accelerated regional carbon losses over the past decade, owing to increases in burn area and late-season burning. As a result, soils in these black spruce stands have become a net source of carbon to the atmosphere, with carbon emissions far exceeding decadal uptake.

  18. Carbon dynamics in aboveground coarse wood biomass of wetland forests in the northern Pantanal, Brazil

    NASA Astrophysics Data System (ADS)

    Schöngart, J.; Arieira, J.; Felfili Fortes, C.; Cezarine de Arruda, E.; Nunes da Cunha, C.

    2008-05-01

    This is the first estimation on carbon dynamics in the aboveground coarse wood biomass (AGWB) of wetland forests in the Pantanal, located in Central Southern America. In four 1-ha plots in stands characterized by the pioneer species Vochysia divergens Pohl (Vochysiaceae) forest inventories (trees ≥10 cm diameter at breast height, DBH) have been performed and converted to predictions of AGWB by five different allometric models using two or three predicting parameters (DBH, tree height, wood density). Best prediction has been achieved using allometric equations with three independent variables. Carbon stocks (50% of AGWB) vary from 7.4 to 100.9 Mg C ha-1 between the four stands. Carbon sequestration differs 0.50-4.24 Mg C ha-1 yr-1 estimated by two growth models derived from tree-ring analysis describing the relationships between age and DBH for V. divergens and other tree species. We find a close correlation between estimated tree age and C-stock, C-sequestration and C-turnover (mean residence of C in AGWB).

  19. Modeling Forest Biomass and Productivity: Coupling Long-Term Inventory and G-LiHT Data

    NASA Astrophysics Data System (ADS)

    Babcock, C. R.; Finley, A.; Cook, B. D.

    2013-12-01

    To better understand how space-based light detection and ranging (LiDAR) and long-term inventory data can be used to map forest above-ground biomass (AGB), we propose and examine a novel modeling approach to improve AGB prediction and estimate productivity. For this analysis we use LiDAR data acquired from NASA Goddard's LiDAR, Hyper-spectral & Thermal (G-LiHT) imager and field inventory data from the Penobscot Experimental Forest (PEF) in Bradley, Maine. Uncertainties associated with plot locations, field inventory measurements, and LiDAR misregistration are always present when modeling these data. Rather than assuming these sources of error are negligible, we choose to account for these and other uncertainties by adopting a Bayesian modeling framework that will afford us the opportunity to specify complex and dynamic model parameter associations and propagate uncertainty through to prediction. Specifically, we specify a space-varying coefficients model to predict and map AGB alongside productivity. The proposed framework models productivity and AGB simultaneously. The proposed model also accommodates temporal misalignment between field measurements and remotely sensed data. Results show that the proposed model outperforms benchmark models in fit and predictive ability as indicated by significant reductions in model deviance information criterion (DIC) and root mean squared prediction error (RMSPE).

  20. Reconstructing Above Ground Forest Biomass Increment and Uncertainty Using Tree-ring Data

    NASA Astrophysics Data System (ADS)

    Dawson, A.; Paciorek, C. J.; Moore, D. J.; Pedersen, N.; Barker Plotkin, A.; Hessl, A. E.; Dye, A.; Bishop, D. A.; Alexander, M. R.; McLachlan, J. S.

    2015-12-01

    In a changing terrestrial climate, it is becoming increasingly important to be able to quantify Earth systems cycles, including thecarbon cycle. Atmospheric concentrations of carbon dioxide continue toincrease as a result of anthropogenic activity, but less is understood about how forest systems will affect the carbon cycle. In practice, it is difficult to measure carbon flux in a forest system. Flux towers, satellite and remote sensing methods, and dynamic vegetation models have been used to quantify current and future forest net primary productivity. Tree rings provide us with information about forest carbon storage in the past, and have been used to reconstruct above ground biomass increment (aBI). However, uncertainty from measurement error, assumptions about tree architecture including circular stems and diameter-volume relationships, and the fading record - the challenge of quantifying the growth of previously live trees - are often not accounted for. As a first step towards reconstructing aBI and its uncertainty, we develop a tree ring sampling protocol and a Bayesian hierarchical model toestimate aBI while accounting for measurement and architecture uncertainty. Tree-ring and repeated census plot data have been collected from several sites using a protocol that allows us toquantify growth dependence across trees in a local area. We also use multiple cores per tree to investigate the number of cores needed to reduce uncertainty from the assumption of stem circularity. For short-time-scale reconstructions, we avoid the fading record issue by coring dead trees and co-locating tree-ring data with censuses, thus avoiding having to make assumptions about stand density andmortality. We also statistically investigate the importance of including census data and of coring dead trees to quantify how uncertainty and bias are affected as we go back further in time. Preliminary results show that the model is able to estimate yearly variation in aBI well for many decades

  1. Aboveground biomass mapping in French Guiana by combining remote sensing, forest inventories and environmental data

    NASA Astrophysics Data System (ADS)

    Fayad, Ibrahim; Baghdadi, Nicolas; Guitet, Stéphane; Bailly, Jean-Stéphane; Hérault, Bruno; Gond, Valéry; El Hajj, Mahmoud; Tong Minh, Dinh Ho

    2016-10-01

    Mapping forest aboveground biomass (AGB) has become an important task, particularly for the reporting of carbon stocks and changes. AGB can be mapped using synthetic aperture radar data (SAR) or passive optical data. However, these data are insensitive to high AGB levels (>150 Mg/ha, and >300 Mg/ha for P-band), which are commonly found in tropical forests. Studies have mapped the rough variations in AGB by combining optical and environmental data at regional and global scales. Nevertheless, these maps cannot represent local variations in AGB in tropical forests. In this paper, we hypothesize that the problem of misrepresenting local variations in AGB and AGB estimation with good precision occurs because of both methodological limits (signal saturation or dilution bias) and a lack of adequate calibration data in this range of AGB values. We test this hypothesis by developing a calibrated regression model to predict variations in high AGB values (mean >300 Mg/ha) in French Guiana by a methodological approach for spatial extrapolation with data from the optical geoscience laser altimeter system (GLAS), forest inventories, radar, optics, and environmental variables for spatial inter- and extrapolation. Given their higher point count, GLAS data allow a wider coverage of AGB values. We find that the metrics from GLAS footprints are correlated with field AGB estimations (R2 = 0.54, RMSE = 48.3 Mg/ha) with no bias for high values. First, predictive models, including remote-sensing, environmental variables and spatial correlation functions, allow us to obtain "wall-to-wall" AGB maps over French Guiana with an RMSE for the in situ AGB estimates of ∼50 Mg/ha and R2 = 0.66 at a 1-km grid size. We conclude that a calibrated regression model based on GLAS with dependent environmental data can produce good AGB predictions even for high AGB values if the calibration data fit the AGB range. We also demonstrate that small temporal and spatial mismatches between field data and GLAS

  2. Directional Profiles of Wind Speed and Turbulence Intensity over Forest and Open Land

    NASA Astrophysics Data System (ADS)

    Beyer, Elisabeth; Dietz, Sebastian; Pinter, Anna

    2014-05-01

    More and more wind turbines are built onshore and reduce the available areas for wind energy. Forests are additional potential for wind energy priority areas. But the high roughness of wooden areas and the resulting turbulences make it difficult to assess sites in forests. In order to cope with this problem some measurements were done inside and outside wooden areas. Therefore met masts equipped with ultra sonic and cup anemometers and LIDAR were used. With the measured wind speed and its standard deviation the turbulence intensity was calculated. The results are direction dependent profiles of wind speed and turbulence intensity.

  3. Complementarities between Biomass and FluxNet data to optimize ORCHIDEE ecosystem model at European forest and grassland sites

    NASA Astrophysics Data System (ADS)

    Thum, T.; Peylin, P.; Granier, A.; Ibrom, A.; Linden, L.; Loustau, D.; Bacour, C.; Ciais, P.

    2010-12-01

    Assimilation of data from several measurements provides knowledge of the model's performance and uncertainties. In this work we investigate the complementary of Biomass data to net CO2 flux (NEE) and latent heat flux (LE) in optimising parameters of the biogeochemical model ORCHIDEE. Our optimisation method is a gradient based iterative method. We optimized the model at the French forest sites, European beech forest of Hesse (48 .67°N, 7.06°E) and maritime pine forest of Le Bray (44.72°N, 0.77°W). First we adapted the model to represent the past clearcut on these two sites in order to obtain a realistic age of the forest. The model-data improvement in terms of aboveground biomass will be discussed. We then used FluxNet and Biomass data, separately and altogether, in the optimization process to assess the potential and the complementarities of these two data stream. For biomass data optimization we added parameters linked to allocation to the optimization scheme. The results show a decrease in the uncertainty of the parameters after optimization and reveal some structural deficiencies in the model. In a second step, data from ecosystem manipulation experiment site Brandbjerg (55.88°N, 11.97°E), a Danish grassland site, were used for model optimisation. The different ecosystem experiments at this site include rain exclusion, warming, and increased CO2 concentration, and only biomass data were available and used in the optimization for the different treatments. We investigate the ability of the model to represent the biomass differences between manipulative experiments with a given set of parameters and highlight model deficiencies.

  4. Birds and bats reduce insect biomass and leaf damage in tropical forest restoration sites.

    PubMed

    Morrison, Emily B; Lindell, Catherine A

    2012-07-01

    Both birds and bats are important insect predators in tropical systems. However, the relative influence of birds and bats on insect populations and their indirect effects on leaf damage have not previously been investigated in tropical forest restoration sites. Leaf damage by herbivorous insects can negatively affect the growth and survival of tropical plants and thus can influence the success of tropical forest restoration efforts. We used an exclosure experiment to examine the top-down effects of birds and bats on insects and leaf damage in a large-scale forest restoration experiment. Given the potential influence of tree planting design on bird and bat abundances, we also investigated planting design effects on bird and bat insectivory and leaf damage. The experiment included two planting treatment plots: islands, where trees were planted in patches, and plantations, where trees were planted in rows to create continuous cover. In both types of plots, insect biomass was highest on tree branches where both birds and bats were excluded from foraging and lowest on branches without exclosures where both birds and bats were present. In the island plots, birds and bats had approximately equal impacts on insect populations, while in plantations bats appeared to have a slightly stronger effect on insects than did birds. In plantations, the levels of leaf damage were higher on branches where birds and bats were excluded than on branches where both had access. In island plots, no significant differences in leaf damage were found between exclosure treatments although potential patterns were in the same direction as in the plantations. Our results suggest that both birds and bats play important roles as top predators in restoration systems by reducing herbivorous insects and their damage to planted trees. Tropical restoration projects should include efforts to attract and provide suitable habitat for birds and bats, given their demonstrated ecological importance.

  5. LiDAR based prediction of forest biomass using hierarchical models with spatially varying coefficients

    USGS Publications Warehouse

    Babcock, Chad; Finley, Andrew O.; Bradford, John B.; Kolka, Randall K.; Birdsey, Richard A.; Ryan, Michael G.

    2015-01-01

    Many studies and production inventory systems have shown the utility of coupling covariates derived from Light Detection and Ranging (LiDAR) data with forest variables measured on georeferenced inventory plots through regression models. The objective of this study was to propose and assess the use of a Bayesian hierarchical modeling framework that accommodates both residual spatial dependence and non-stationarity of model covariates through the introduction of spatial random effects. We explored this objective using four forest inventory datasets that are part of the North American Carbon Program, each comprising point-referenced measures of above-ground forest biomass and discrete LiDAR. For each dataset, we considered at least five regression model specifications of varying complexity. Models were assessed based on goodness of fit criteria and predictive performance using a 10-fold cross-validation procedure. Results showed that the addition of spatial random effects to the regression model intercept improved fit and predictive performance in the presence of substantial residual spatial dependence. Additionally, in some cases, allowing either some or all regression slope parameters to vary spatially, via the addition of spatial random effects, further improved model fit and predictive performance. In other instances, models showed improved fit but decreased predictive performance—indicating over-fitting and underscoring the need for cross-validation to assess predictive ability. The proposed Bayesian modeling framework provided access to pixel-level posterior predictive distributions that were useful for uncertainty mapping, diagnosing spatial extrapolation issues, revealing missing model covariates, and discovering locally significant parameters.

  6. Implication of Forest-Savanna Dynamics on Biomass and Carbon Stock: Effectiveness of an Amazonian Ecological Station

    NASA Astrophysics Data System (ADS)

    Couto-Santos, F. R.; Luizao, F. J.

    2014-12-01

    The forests-savanna advancement/retraction process seems to play an important role in the global carbon cycle and in the climate-vegetation balance maintenance in the Amazon. To contribute with long term carbon dynamics and assess effectiveness of a protected area in reduce carbon emissions in Brazilian Amazon transitional areas, variations in forest-savanna mosaics biomass and carbon stock within Maraca Ecological Station (MES), Roraima/Brazil, and its outskirts non-protected areas were compared. Composite surface soil samples and indirect methods based on regression models were used to estimate aboveground tree biomass accumulation and assess vegetation and soil carbon stock along eleven 0.6 ha transects perpendicular to the forest-savanna limits. Aboveground biomass and carbon accumulation were influenced by vegetation structure, showing higher values within protected area, with great contribution of trees above 40 cm in diameter. In the savanna environments of protected areas, a higher tree density and carbon stock up to 30 m from the border confirmed a forest encroachment. This pointed that MES acts as carbon sink, even under variations in soil fertility gradient, with a potential increase of the total carbon stock from 9 to 150 Mg C ha-1. Under 20 years of fire and disturbance management, the results indicated the effectiveness of this protected area to reduce carbon emissions and mitigate greenhouse and climate change effects in a forest-savanna transitional area in Brazilian Northern Amazon. The contribution of this study in understanding rates and reasons for biomass and carbon variation, under different management strategies, should be considered the first approximation to assist policies of reducing emissions from deforestation and forest degradation (REDD) from underresearched Amazonian ecotone; despite further efforts in this direction are still needed. FINANCIAL SUPPORT: Boticário Group Foundation (Fundação Grupo Boticário); National Council for

  7. Tropical-Forest Biomass Dynamics from X-Band, TanDEM-X DATA

    NASA Astrophysics Data System (ADS)

    Treuhaft, R. N.; Neumann, M.; Keller, M. M.; Goncalves, F. G.; Santos, J. R.

    2015-12-01

    The measurement of the change in above ground biomass (AGB) is key for understanding the carbon sink/source nature of tropical forests. Interferometric X-band radar from the only orbiting interferometer, TanDEM-X, shows sensitivity to standing biomass up to at least 300 Mg/ha. This sensitivity may be due in part to the propagation of the shorter X-band wavelength (0.031 m) through holes in the canopy. This talk focuses on estimating the change in AGB over time. Interferometric baselines from TanDEM-X have been obtained in Tapajós National Forest in the Brazilian Amazon over a 4-year period, from 2011 to 2015. Lidar measurements were also acquired during this period. Field measurements of height, height-to-base-of-crown, species, diameter, and position were acquired in 2010, 2013, and 2015. We show interferometric phase height changes, and suggest how these phase height changes are related to biomass change. First we show height changes between baselines separated by one month, over which we expect no change in AGB, to evaluate precision. We find an RMS of <2 m for ~85 stands in the phase height over one month, corresponding to about a 10% measurement of change, which suggests we can detect about a 17 Mg/ha change in AGB at Tapajos. In contrast, interferometric height changes over the period 2011 to 2014 have larger RMS scatters of > 3 m, due to actual change. Most stands show changes in interferometric phase height consistent with regrowth (~10 Mg/ha/yr), and several stands show abrupt, large changes in phase height (>10 m) due to logging and natural disturbance. At the end of 2015, we will acquire more TanDEM-X data over Tapajos, including an area subjected to selective logging. We are doing "before" (March 2015) and "after" (October 2015) fieldwork to be able to understand the signature of change due to selective logging in TanDEM-X interferometric data.

  8. Accounting for spatial variation in vegetation properties improves simulations of Amazon forest biomass and productivity in a global vegetation model

    NASA Astrophysics Data System (ADS)

    de Almeida Castanho, A. D.; Coe, M. T.; Heil Costa, M.; Malhi, Y.; Galbraith, D.; Quesada, C. A.

    2012-08-01

    Dynamic vegetation models forced with spatially homogeneous biophysical parameters are capable of producing average productivity and biomass values for the Amazon basin forest biome that are close to the observed estimates, but are unable to reproduce the observed spatial variability. Recent observational studies have shown substantial regional spatial variability of above-ground productivity and biomass across the Amazon basin, which is believed to be primarily driven by soil physical and chemical properties. In this study, spatial heterogeneity of vegetation properties is added to the IBIS land surface model, and the simulated productivity and biomass of the Amazon basin are compared to observations from undisturbed forest. The maximum Rubisco carboxylation capacity (Vcmax) and the woody biomass residence time (τw) were found to be the most important properties determining the modeled spatial variation of above-ground woody net primary productivity and biomass, respectively. Spatial heterogeneity of these properties may lead to a spatial variability of 1.8 times in the simulated woody net primary productivity and 2.8 times in the woody above-ground biomass. The coefficient of correlation between the modeled and observed woody productivity improved from 0.10 with homogeneous parameters to 0.73 with spatially heterogeneous parameters, while the coefficient of correlation between the simulated and observed woody above-ground biomass improved from 0.33 to 0.88. The results from our analyses with the IBIS dynamic vegetation model demonstrate that using single values for key ecological parameters in the tropical forest biome severely limits simulation accuracy. We emphasize that our approach must be viewed as an important first step and that a clearer understanding of the biophysical mechanisms that drive the spatial variability of carbon allocation, τw and Vcmax are necessary.

  9. Multi-decade biomass dynamics in an old-growth hemlock-northern hardwood forest, Michigan, USA.

    PubMed

    Woods, Kerry D

    2014-01-01

    Trends in living aboveground biomass and inputs to the pool of coarse woody debris (CWD) in an undisturbed, old-growth hemlock-northern hardwood forest in northern MI were estimated from multi-decade observations of permanent plots. Growth and demographic data from seven plot censuses over 47 years (1962-2009), combined with one-time measurement of CWD pools, help assess biomass/carbon status of this landscape. Are trends consistent with traditional notions of late-successional forests as equilibrial ecosystems? Specifically, do biomass pools and CWD inputs show consistent long-term trends and relationships, and can living and dead biomass pools and trends be related to forest composition and history? Aboveground living biomass densities, estimated using standard allometric relationships, range from 360-450 Mg/ha among sampled stands and types; these values are among the highest recorded for northeastern North American forests. Biomass densities showed significant decade-scale variation, but no consistent trends over the full study period (one stand, originating following an 1830 fire, showed an aggrading trend during the first 25 years of the study). Even though total above-ground biomass pools are neither increasing nor decreasing, they have been increasingly dominated, over the full study period, by very large (>70 cm dbh) stems and by the most shade-tolerant species (Acer saccharum and Tsuga canadensis). CWD pools measured in 2007 averaged 151 m(3)/ha, with highest values in Acer-dominated stands. Snag densities averaged 27/ha, but varied nearly ten-fold with canopy composition (highest in Tsuga-dominated stands, lowest in Acer-dominated); snags constituted 10-50% of CWD biomass. Annualized CWD inputs from tree mortality over the full study period averaged 1.9-3.2 Mg/ha/yr, depending on stand and species composition. CWD input rates tended to increase over the course of the study. Input rates may be expected to increase over longer-term observations because, (a

  10. Interactions between Canopy Structure and Herbaceous Biomass along Environmental Gradients in Moist Forest and Dry Miombo Woodland of Tanzania

    PubMed Central

    Shirima, Deo D.; Pfeifer, Marion; Platts, Philip J.; Totland, Ørjan; Moe, Stein R.

    2015-01-01

    We have limited understanding of how tropical canopy foliage varies along environmental gradients, and how this may in turn affect forest processes and functions. Here, we analyse the relationships between canopy leaf area index (LAI) and above ground herbaceous biomass (AGBH) along environmental gradients in a moist forest and miombo woodland in Tanzania. We recorded canopy structure and herbaceous biomass in 100 permanent vegetation plots (20 m × 40 m), stratified by elevation. We quantified tree species richness, evenness, Shannon diversity and predominant height as measures of structural variability, and disturbance (tree stumps), soil nutrients and elevation as indicators of environmental variability. Moist forest and miombo woodland differed substantially with respect to nearly all variables tested. Both structural and environmental variables were found to affect LAI and AGBH, the latter being additionally dependent on LAI in moist forest but not in miombo, where other factors are limiting. Combining structural and environmental predictors yielded the most powerful models. In moist forest, they explained 76% and 25% of deviance in LAI and AGBH, respectively. In miombo woodland, they explained 82% and 45% of deviance in LAI and AGBH. In moist forest, LAI increased non-linearly with predominant height and linearly with tree richness, and decreased with soil nitrogen except under high disturbance. Miombo woodland LAI increased linearly with stem density, soil phosphorous and nitrogen, and decreased linearly with tree species evenness. AGBH in moist forest decreased with LAI at lower elevations whilst increasing slightly at higher elevations. AGBH in miombo woodland increased linearly with soil nitrogen and soil pH. Overall, moist forest plots had denser canopies and lower AGBH compared with miombo plots. Further field studies are encouraged, to disentangle the direct influence of LAI on AGBH from complex interrelationships between stand structure, environmental

  11. Quantifying Post-Fire Forest Biomass Recovery in Northeastern Siberia using Hierarchical Multi-Sensor Satellite Imagery and Field Measurements

    NASA Astrophysics Data System (ADS)

    Berner, L.; Beck, P. S.; Loranty, M. M.; Alexander, H. D.; Mack, M. C.; Goetz, S. J.

    2011-12-01

    Russian forests are the largest vegetation carbon pool outside of the tropics, with larch dominating northeastern Siberia where extreme temperatures, permafrost and wildfire currently limit persistence of other tree species. These ecosystems have experienced rapid climate warming over the past century and model simulations suggest that they will undergo profound changes by the end of the century if warming continues. Understanding the responses of these unique deciduous-conifer ecosystems to current and future climate is important given the potential changes in disturbance regimes and other climate feedbacks. The climate implications of changes in fire severity and return interval, as predicted under a warmer and drier climate, are not well understood given the trade-off between storage of C in forest biomass and post-fire surface albedo. We examined forest biomass recovery across a burn chronosequence near Cherskii, Sakha Republic, in far northeastern Siberia. We used high-quality Landsat imagery to date and map fires that occurred between 1972 and 2009, then complemented this data set using tree ring measurements to map older fires. A three stage approach was taken to map current biomass distribution. First, tree shadows were mapped from 50 cm panchromatic WorldView 1 imagery covering a portion of the region. Secondly, the tree shadow map was aggregated to 30 m resolution and used to train a regression-tree model that ingested mosaiced Landsat data. The model output correlated with allometry-based field estimates of biomass, allowing us to transform the model output to a map of regional aboveground biomass using a regression model. When combined with the fire history data, the new biomass map revealed a chronosequence of forest regrowth and carbon sequestration in aboveground biomass after fire. We discuss the potential for future carbon emissions from fires in northeastern Siberia, as well as carbon sequestration during recovery based on the observed biomass

  12. Biomass estimation in a tropical wet forest using Fourier transforms of profiles from lidar or interferometric SAR

    NASA Astrophysics Data System (ADS)

    Treuhaft, R. N.; Gonçalves, F. G.; Drake, J. B.; Chapman, B. D.; dos Santos, J. R.; Dutra, L. V.; Graça, P. M. L. A.; Purcell, G. H.

    2010-12-01

    Tropical forest biomass estimation based on the structure of the canopy is a burgeoning and crucial remote sensing capability for balancing terrestrial carbon budgets. This paper introduces a new approach to structural biomass estimation based on the Fourier transform of vertical profiles from lidar or interferometric SAR (InSAR). Airborne and field data were used from 28 tropical wet forest stands at La Selva Biological Station, Costa Rica, with average biomass of 229 Mg-ha-1. RMS scatters of remote sensing biomass estimates about field measurements were 58.3 Mg-ha-1, 21%, and 76.1 Mg-ha-1, 26%, for lidar and InSAR, respectively. Using mean forest height, the RMS scatter was 97 Mg-ha-1, ≈34% for both lidar and InSAR. The confidence that Fourier transforms are a significant improvement over height was >99% for lidar and ≈90% for InSAR. Lidar Fourier transforms determined the useful range of vertical wavelengths to be 14 m to 100 m.

  13. Investigating Appropriate Sampling Design for Estimating Above-Ground Biomass in Bruneian Lowland Mixed Dipterocarp Forest

    NASA Astrophysics Data System (ADS)

    Lee, S.; Lee, D.; Abu Salim, K.; Yun, H. M.; Han, S.; Lee, W. K.; Davies, S. J.; Son, Y.

    2014-12-01

    Mixed tropical forest structure is highly heterogeneous unlike plantation or mixed temperate forest structure, and therefore, different sampling approaches are required. However, the appropriate sampling design for estimating the above-ground biomass (AGB) in Bruneian lowland mixed dipterocarp forest (MDF) has not yet been fully clarified. The aim of this study was to provide supportive information in sampling design for Bruneian forest carbon inventory. The study site was located at Kuala Belalong lowland MDF, which is part of the Ulu Tembulong National Park, Brunei Darussalam. Six 60 m × 60 m quadrats were established, separated by a distance of approximately 100 m and each was subdivided into quadrats of 10 m × 10 m, at an elevation between 200 and 300 m above sea level. At each plot all free-standing trees with diameter at breast height (dbh) ≥ 1 cm were measured. The AGB for all trees with dbh ≥ 10 cm was estimated by allometric models. In order to analyze changes in the diameter-dependent parameters used for estimating the AGB, different quadrat areas, ranging from 10 m × 10 m to 60 m × 60 m, were used across the study area, starting at the South-West end and moving towards the North-East end. The derived result was as follows: (a) Big trees (dbh ≥ 70 cm) with sparse distribution have remarkable contribution to the total AGB in Bruneian lowland MDF, and therefore, special consideration is required when estimating the AGB of big trees. Stem number of trees with dbh ≥ 70 cm comprised only 2.7% of all trees with dbh ≥ 10 cm, but 38.5% of the total AGB. (b) For estimating the AGB of big trees at the given acceptable limit of precision (p), it is more efficient to use large quadrats than to use small quadrats, because the total sampling area decreases with the former. Our result showed that 239 20 m × 20 m quadrats (9.6 ha in total) were required, while 15 60 m × 60 m quadrats (5.4 ha in total) were required when estimating the AGB of the trees

  14. Raccoon spatial requirements and multi-scale habitat selection within an intensively managed central Appalachian forest

    USGS Publications Warehouse

    Owen, Sheldon F.; Berl, Jacob L.; Edwards, John W.; Ford, W. Mark; Wood, Petra Bohall

    2015-01-01

    We studied a raccoon (Procyon lotor) population within a managed central Appalachian hardwood forest in West Virginia to investigate the effects of intensive forest management on raccoon spatial requirements and habitat selection. Raccoon home-range (95% utilization distribution) and core-area (50% utilization distribution) size differed between sexes with males maintaining larger (2×) home ranges and core areas than females. Home-range and core-area size did not differ between seasons for either sex. We used compositional analysis to quantify raccoon selection of six different habitat types at multiple spatial scales. Raccoons selected riparian corridors (riparian management zones [RMZ]) and intact forests (> 70 y old) at the core-area spatial scale. RMZs likely were used by raccoons because they provided abundant denning resources (i.e., large-diameter trees) as well as access to water. Habitat composition associated with raccoon foraging locations indicated selection for intact forests, riparian areas, and regenerating harvest (stands <10 y old). Although raccoons were able to utilize multiple habitat types for foraging resources, a selection of intact forest and RMZs at multiple spatial scales indicates the need of mature forest (with large-diameter trees) for this species in managed forests in the central Appalachians.

  15. On tree intensity estimation for forest inventories: Some statistical issues.

    PubMed

    Comas, Carlos; Mateu, Jorge; Delicado, Pedro

    2011-11-01

    The effect of the plot shape, number of subplots and their spatial arrangement on the sample variance for spatially explicit point populations is analysed for a simple intensity estimator. We derive the sample variance and covariance for sampling designs involving more than one subplot. Some numerical approximations are also presented. If a clustered point pattern has to be sampled, the best strategy to reduce the sample variance is to consider as many rectangular subplots as possible, for a prescribed total sample area, distributed over a grid. In contrast, if a regular point pattern is to be sampled, then a single circular subplot should be considered. If we assume that the point configuration is Poisson, then we can consider any subplot shape and spatial distribution ensuring no overlapping between the subplots. A case study in forestry is considered to assess the validity of our results.

  16. [Estimating individual tree aboveground biomass of the mid-subtropical forest using airborne LiDAR technology].

    PubMed

    Liu, Feng; Tan, Chang; Lei, Pi-Feng

    2014-11-01

    Taking Wugang forest farm in Xuefeng Mountain as the research object, using the airborne light detection and ranging (LiDAR) data under leaf-on condition and field data of concomitant plots, this paper assessed the ability of using LiDAR technology to estimate aboveground biomass of the mid-subtropical forest. A semi-automated individual tree LiDAR cloud point segmentation was obtained by using condition random fields and optimization methods. Spatial structure, waveform characteristics and topography were calculated as LiDAR metrics from the segmented objects. Then statistical models between aboveground biomass from field data and these LiDAR metrics were built. The individual tree recognition rates were 93%, 86% and 60% for coniferous, broadleaf and mixed forests, respectively. The adjusted coefficients of determination (R(2)adj) and the root mean squared errors (RMSE) for the three types of forest were 0.83, 0.81 and 0.74, and 28.22, 29.79 and 32.31 t · hm(-2), respectively. The estimation capability of model based on canopy geometric volume, tree percentile height, slope and waveform characteristics was much better than that of traditional regression model based on tree height. Therefore, LiDAR metrics from individual tree could facilitate better performance in biomass estimation.

  17. Catchment hydro-biogeochemical response to forest harvest intensity and spatial pattern

    EPA Science Inventory

    We apply a new model, Visualizing Ecosystems for Land Management Assessment (VELMA), to Watershed 10 (WS10) in the H.J. Andrews Experimental Forest to simulate the effects of harvest intensity and spatial pattern on catchment hydrological and biogeochemical processes. Specificall...

  18. Estimating aboveground forest biomass carbon and fire consumption in the U.S. Utah High Plateaus using data from the Forest Inventory and Analysis program, Landsat, and LANDFIRE

    USGS Publications Warehouse

    Chen, X.; Liu, S.; Zhu, Z.; Vogelmann, J.; Li, Z.; Ohlen, D.

    2011-01-01

    The concentrations of CO2 and other greenhouse gases in the atmosphere have been increasing and greatly affecting global climate and socio-economic systems. Actively growing forests are generally considered to be a major carbon sink, but forest wildfires lead to large releases of biomass carbon into the atmosphere. Aboveground forest biomass carbon (AFBC), an important ecological indicator, and fire-induced carbon emissions at regional scales are highly relevant to forest sustainable management and climate change. It is challenging to accurately estimate the spatial distribution of AFBC across large areas because of the spatial heterogeneity of forest cover types and canopy structure. In this study, Forest Inventory and Analysis (FIA) data, Landsat, and Landscape Fire and Resource Management Planning Tools Project (LANDFIRE) data were integrated in a regression tree model for estimating AFBC at a 30-m resolution in the Utah High Plateaus. AFBC were calculated from 225 FIA field plots and used as the dependent variable in the model. Of these plots, 10% were held out for model evaluation with stratified random sampling, and the other 90% were used as training data to develop the regression tree model. Independent variable layers included Landsat imagery and the derived spectral indicators, digital elevation model (DEM) data and derivatives, biophysical gradient data, existing vegetation cover type and vegetation structure. The cross-validation correlation coefficient (r value) was 0.81 for the training model. Independent validation using withheld plot data was similar with r value of 0.82. This validated regression tree model was applied to map AFBC in the Utah High Plateaus and then combined with burn severity information to estimate loss of AFBC in the Longston fire of Zion National Park in 2001. The final dataset represented 24 forest cover types for a 4 million ha forested area. We estimated a total of 353 Tg AFBC with an average of 87 MgC/ha in the Utah High

  19. ABOVEGROUND BIOMASS DISTRIBUTION OF US EASTERN HARDWOOD FORESTS AND THE USE OF LARGE TREES AS AN INDICATOR OF FOREST DEVELOPMENT

    EPA Science Inventory

    Past clearing and harvesting of the deciduous hardwood forests of eastern USA released large amount of carbon dioxide into the atmosphere, but through recovery and regrowth these forests are now accumulating atmospheric carbon (C). This study examined quantities and distribution ...

  20. Using LiDAR Data to Measure the 3D Green Biomass of Beijing Urban Forest in China

    PubMed Central

    He, Cheng; Convertino, Matteo; Feng, Zhongke; Zhang, Siyu

    2013-01-01

    The purpose of the paper is to find a new approach to measure 3D green biomass of urban forest and to testify its precision. In this study, the 3D green biomass could be acquired on basis of a remote sensing inversion model in which each standing wood was first scanned by Terrestrial Laser Scanner to catch its point cloud data, then the point cloud picture was opened in a digital mapping data acquisition system to get the elevation in an independent coordinate, and at last the individual volume captured was associated with the remote sensing image in SPOT5(System Probatoired'Observation dela Tarre)by means of such tools as SPSS (Statistical Product and Service Solutions), GIS (Geographic Information System), RS (Remote Sensing) and spatial analysis software (FARO SCENE and Geomagic studio11). The results showed that the 3D green biomass of Beijing urban forest was 399.1295 million m3, of which coniferous was 28.7871 million m3 and broad-leaf was 370.3424 million m3. The accuracy of 3D green biomass was over 85%, comparison with the values from 235 field sample data in a typical sampling way. This suggested that the precision done by the 3D forest green biomass based on the image in SPOT5 could meet requirements. This represents an improvement over the conventional method because it not only provides a basis to evalue indices of Beijing urban greenings, but also introduces a new technique to assess 3D green biomass in other cities. PMID:24146792

  1. Using LiDAR data to measure the 3D green biomass of Beijing urban forest in China.

    PubMed

    He, Cheng; Convertino, Matteo; Feng, Zhongke; Zhang, Siyu

    2013-01-01

    The purpose of the paper is to find a new approach to measure 3D green biomass of urban forest and to testify its precision. In this study, the 3D green biomass could be acquired on basis of a remote sensing inversion model in which each standing wood was first scanned by Terrestrial Laser Scanner to catch its point cloud data, then the point cloud picture was opened in a digital mapping data acquisition system to get the elevation in an independent coordinate, and at last the individual volume captured was associated with the remote sensing image in SPOT5(System Probatoired'Observation dela Tarre)by means of such tools as SPSS (Statistical Product and Service Solutions), GIS (Geographic Information System), RS (Remote Sensing) and spatial analysis software (FARO SCENE and Geomagic studio11). The results showed that the 3D green biomass of Beijing urban forest was 399.1295 million m(3), of which coniferous was 28.7871 million m(3) and broad-leaf was 370.3424 million m(3). The accuracy of 3D green biomass was over 85%, comparison with the values from 235 field sample data in a typical sampling way. This suggested that the precision done by the 3D forest green biomass based on the image in SPOT5 could meet requirements. This represents an improvement over the conventional method because it not only provides a basis to evalue indices of Beijing urban greenings, but also introduces a new technique to assess 3D green biomass in other cities.

  2. Predicting biomass of hyperdiverse and structurally complex central Amazonian forests - a virtual approach using extensive field data

    NASA Astrophysics Data System (ADS)

    Magnabosco Marra, Daniel; Higuchi, Niro; Trumbore, Susan E.; Ribeiro, Gabriel H. P. M.; dos Santos, Joaquim; Carneiro, Vilany M. C.; Lima, Adriano J. N.; Chambers, Jeffrey Q.; Negrón-Juárez, Robinson I.; Holzwarth, Frederic; Reu, Björn; Wirth, Christian

    2016-03-01

    Old-growth forests are subject to substantial changes in structure and species composition due to the intensification of human activities, gradual climate change and extreme weather events. Trees store ca. 90 % of the total aboveground biomass (AGB) in tropical forests and precise tree biomass estimation models are crucial for management and conservation. In the central Amazon, predicting AGB at large spatial scales is a challenging task due to the heterogeneity of successional stages, high tree species diversity and inherent variations in tree allometry and architecture. We parameterized generic AGB estimation models applicable across species and a wide range of structural and compositional variation related to species sorting into height layers as well as frequent natural disturbances. We used 727 trees (diameter at breast height ≥ 5 cm) from 101 genera and at least 135 species harvested in a contiguous forest near Manaus, Brazil. Sampling from this data set we assembled six scenarios designed to span existing gradients in floristic composition and size distribution in order to select models that best predict AGB at the landscape level across successional gradients. We found that good individual tree model fits do not necessarily translate into reliable predictions of AGB at the landscape level. When predicting AGB (dry mass) over scenarios using our different models and an available pantropical model, we observed systematic biases ranging from -31 % (pantropical) to +39 %, with root-mean-square error (RMSE) values of up to 130 Mg ha-1 (pantropical). Our first and second best models had both low mean biases (0.8 and 3.9 %, respectively) and RMSE (9.4 and 18.6 Mg ha-1) when applied over scenarios. Predicting biomass correctly at the landscape level in hyperdiverse and structurally complex tropical forests, especially allowing good performance at the margins of data availability for model construction/calibration, requires the inclusion of predictors that express

  3. Biomass burning drives atmospheric nutrient redistribution within forested peatlands in Borneo

    NASA Astrophysics Data System (ADS)

    Ponette-González, Alexandra G.; Curran, Lisa M.; Pittman, Alice M.; Carlson, Kimberly M.; Steele, Bethel G.; Ratnasari, Dessy; Mujiman; Weathers, Kathleen C.

    2016-08-01

    Biomass burning plays a critical role not only in atmospheric emissions, but also in the deposition and redistribution of biologically important nutrients within tropical landscapes. We quantified the influence of fire on biogeochemical fluxes of nitrogen (N), phosphorus (P), and sulfur (S) in a 12 ha forested peatland in West Kalimantan, Indonesia. Total (inorganic + organic) N, {{{{NO}}}3}- -N, {{{{NH}}}4}+ -N, total P, {{{{PO}}}4}3- -P, and {{{{SO}}}4}2- -S fluxes were measured in throughfall and bulk rainfall weekly from July 2013 to September 2014. To identify fire events, we used concentrations of particulate matter (PM10) and MODIS Active Fire Product counts within 20 and 100 km radius buffers surrounding the site. Dominant sources of throughfall nutrient deposition were explored using cluster and back-trajectory analysis. Our findings show that this Bornean peatland receives some of the highest P (7.9 kg {{{{PO}}}4}3- -P ha-1yr-1) and S (42 kg {{{{SO}}}4}2- -S ha-1yr-1) deposition reported globally, and that N deposition (8.7 kg inorganic N ha-1yr-1) exceeds critical load limits suggested for tropical forests. Six major dry periods and associated fire events occurred during the study. Seventy-eight percent of fires within 20 km and 40% within 100 km of the site were detected within oil palm plantation leases (industrial agriculture) on peatlands. These fires had a disproportionate impact on below-canopy nutrient fluxes. Post-fire throughfall events contributed >30% of the total inorganic N ({{{{NO}}}3}- -N + {{{{NH}}}4}+ -N) and {{{{PO}}}4}3- -P flux to peatland soils during the study period. Our results indicate that biomass burning associated with agricultural peat fires is a major source of N, P, and S in throughfall and could rival industrial pollution as an input to these systems during major fire years. Given the sheer magnitude of fluxes reported here, fire-related redistribution of nutrients may have significant fertilizing or acidifying effects on

  4. Estimation of aboveground biomass in Mediterranean forests by statistical modelling of ASTER fraction images

    NASA Astrophysics Data System (ADS)

    Fernández-Manso, O.; Fernández-Manso, A.; Quintano, C.

    2014-09-01

    Aboveground biomass (AGB) estimation from optical satellite data is usually based on regression models of original or synthetic bands. To overcome the poor relation between AGB and spectral bands due to mixed-pixels when a medium spatial resolution sensor is considered, we propose to base the AGB estimation on fraction images from Linear Spectral Mixture Analysis (LSMA). Our study area is a managed Mediterranean pine woodland (Pinus pinaster Ait.) in central Spain. A total of 1033 circular field plots were used to estimate AGB from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) optical data. We applied Pearson correlation statistics and stepwise multiple regression to identify suitable predictors from the set of variables of original bands, fraction imagery, Normalized Difference Vegetation Index and Tasselled Cap components. Four linear models and one nonlinear model were tested. A linear combination of ASTER band 2 (red, 0.630-0.690 μm), band 8 (short wave infrared 5, 2.295-2.365 μm) and green vegetation fraction (from LSMA) was the best AGB predictor (Radj2=0.632, the root-mean-squared error of estimated AGB was 13.3 Mg ha-1 (or 37.7%), resulting from cross-validation), rather than other combinations of the above cited independent variables. Results indicated that using ASTER fraction images in regression models improves the AGB estimation in Mediterranean pine forests. The spatial distribution of the estimated AGB, based on a multiple linear regression model, may be used as baseline information for forest managers in future studies, such as quantifying the regional carbon budget, fuel accumulation or monitoring of management practices.

  5. Mercury emissions from burning of biomass from temperate North American forests: laboratory and airborne measurements

    NASA Astrophysics Data System (ADS)

    Friedli, H. R.; Radke, L. F.; Lu, J. Y.; Banic, C. M.; Leaitch, W. R.; MacPherson, J. I.

    The emission of mercury from biomass burning was investigated in laboratory experiments and the results confirmed in airborne measurements on a wildfire near Hearst, Ont. Mercury contained in vegetation (live, dead, coniferous, deciduous) was essentially completely released in laboratory burns in the form of gaseous elemental mercury and mercury contained in particles. Replicate burns of dry Ponderosa needles indicated a linear relationship between emitted mercury and fuel mass loss. Regionally collected fuels showed the same behavior as the replicate burns, i.e. essentially total removal of mercury. Mercury released from fuel could be accounted for as gaseous and particulate mercury in the smoke. The mercury content of regionally collected fuels varied between 14 and 70 ng/g on a dry mass (dm) basis. The smoke plume from a small wildfire was investigated with a research aircraft yielding a mean output of 0.15±0.02 ng/m 3 of elemental mercury for each ppm of CO 2 emitted. The particulate mercury determined by sampling at specific points in the plume was <0.083 ng/m 3 compared to elemental mercury of 0.56 ng/m 3 for the same air, supporting the conclusion that most of the mercury was emitted in the gaseous elemental form. Emission factors for the high/low mercury content samples of the laboratory burns were 14-71×10 -6 and 112×10 -6 g Hg/kg (dm) fuel for the wildfire. The difference is believed to be the contribution of mercury released from fire-heated soil. Mercury budgets extrapolated from this single wildfire gave upper emission limits of 66 t/yr for temperate/boreal forests. This large source estimate must be refined and included in future regional and global models. Forests are sinks for mercury already in the atmosphere, thus the wildfire "source" is part of the overall cycling of mercury originating from other sources.

  6. Structural, physiognomic and above-ground biomass variation in savanna-forest transition zones on three continents - how different are co-occurring savanna and forest formations?

    NASA Astrophysics Data System (ADS)

    Veenendaal, E. M.; Torello-Raventos, M.; Feldpausch, T. R.; Domingues, T. F.; Gerard, F.; Schrodt, F.; Saiz, G.; Quesada, C. A.; Djagbletey, G.; Ford, A.; Kemp, J.; Marimon, B. S.; Marimon-Junior, B. H.; Lenza, E.; Ratter, J. A.; Maracahipes, L.; Sasaki, D.; Sonke, B.; Zapfack, L.; Villarroel, D.; Schwarz, M.; Yoko Ishida, F.; Gilpin, M.; Nardoto, G. B.; Affum-Baffoe, K.; Arroyo, L.; Bloomfield, K.; Ceca, G.; Compaore, H.; Davies, K.; Diallo, A.; Fyllas, N. M.; Gignoux, J.; Hien, F.; Johnson, M.; Mougin, E.; Hiernaux, P.; Killeen, T.; Metcalfe, D.; Miranda, H. S.; Steininger, M.; Sykora, K.; Bird, M. I.; Grace, J.; Lewis, S.; Phillips, O. L.; Lloyd, J.

    2015-05-01

    Through interpretations of remote-sensing data and/or theoretical propositions, the idea that forest and savanna represent "alternative stable states" is gaining increasing acceptance. Filling an observational gap, we present detailed stratified floristic and structural analyses for forest and savanna stands located mostly within zones of transition (where both vegetation types occur in close proximity) in Africa, South America and Australia. Woody plant leaf area index variation was related to tree canopy cover in a similar way for both savanna and forest with substantial overlap between the two vegetation types. As total woody plant canopy cover increased, so did the relative contribution of middle and lower strata of woody vegetation. Herbaceous layer cover declined as woody cover increased. This pattern of understorey grasses and herbs progressively replaced by shrubs as the canopy closes over was found for both savanna and forests and on all continents. Thus, once subordinate woody canopy layers are taken into account, a less marked transition in woody plant cover across the savanna-forest-species discontinuum is observed compared to that inferred when trees of a basal diameter > 0.1 m are considered in isolation. This is especially the case for shrub-dominated savannas and in taller savannas approaching canopy closure. An increased contribution of forest species to the total subordinate cover is also observed as savanna stand canopy closure occurs. Despite similarities in canopy-cover characteristics, woody vegetation in Africa and Australia attained greater heights and stored a greater amount of above-ground biomass than in South America. Up to three times as much above-ground biomass is stored in forests compared to savannas under equivalent climatic conditions. Savanna-forest transition zones were also found to typically occur at higher precipitation regimes for South America than for Africa. Nevertheless, consistent across all three continents coexistence

  7. Assessment of forest nutrient pools in view of biomass potentials - a case study from Austria oak stands

    NASA Astrophysics Data System (ADS)

    Yan, S.; Bruckman, V. J.; Glatzel, G.; Hochbichler, E.

    2012-04-01

    As one of the renewable energy forms, bio-energy could help to relieve the pressure which is caused by growing global energy demand. In Austria, large area of forests, traditional utilization of biomass and people's desire to live in a sound environment have supported the positive development of bio-energy. Soil nutrient status is in principle linked with the productivity of the aboveground biomass. This study focuses on K, Ca and Mg pools in soils and aboveground biomass in order to learn more on the temporal dynamics of plant nutrients as indicators for biomass potentials in Quercus dominated forests in northeastern Austria. Three soil types (according to WRB: eutric cambisol, calcic chernozem and haplic luvisol) were considered representative for the area and sampled. We selected nine Quercus petraea dominated permanent plots for this study. Exchangeable cations K, Ca and Mg in the soils were quantified in our study plots. Macronutrients pools of K, Ca and Mg in aboveground biomass were calculated according to inventory data and literature review. The exchangeable cations pool in the top 50 cm of the soil were 882 - 1,652 kg ha-1 for K, 2,661 to 16,510 kg ha-1 for Ca and 320 - 1,850 kg ha-1 for Mg. The nutrient pool in aboveground biomass ranged from 29 to 181 kg ha-1 for K, from 56 to 426 kg ha-1 for Ca and from 4 to 26 kg ha-1 for Mg. The underground exchangeable pools of K, Ca and Mg are generally 10, 22 and 58 times higher than aboveground biomass nutrient pools. Our results showed that the nutrient pools in the mineral soil are sufficient to support the tree growth. The levels of soil nutrients in particular K, Ca and Mg in our study areas are reasonably high and do not indicate the necessity for additional fertilization under current silvicultural practices and biomass extraction rate. The forest in our study areas is in favorable condition to supply biomass as raw material for energy utilization.

  8. Modelling Variable Fire Severity in Boreal Forests: Effects of Fire Intensity and Stand Structure.

    PubMed

    Miquelajauregui, Yosune; Cumming, Steven G; Gauthier, Sylvie

    2016-01-01

    It is becoming clear that fires in boreal forests are not uniformly stand-replacing. On the contrary, marked variation in fire severity, measured as tree mortality, has been found both within and among individual fires. It is important to understand the conditions under which this variation can arise. We integrated forest sample plot data, tree allometries and historical forest fire records within a diameter class-structured model of 1.0 ha patches of mono-specific black spruce and jack pine stands in northern Québec, Canada. The model accounts for crown fire initiation and vertical spread into the canopy. It uses empirical relations between fire intensity, scorch height, the percent of crown scorched and tree mortality to simulate fire severity, specifically the percent reduction in patch basal area due to fire-caused mortality. A random forest and a regression tree analysis of a large random sample of simulated fires were used to test for an effect of fireline intensity, stand structure, species composition and pyrogeographic regions on resultant severity. Severity increased with intensity and was lower for jack pine stands. The proportion of simulated fires that burned at high severity (e.g. >75% reduction in patch basal area) was 0.80 for black spruce and 0.11 for jack pine. We identified thresholds in intensity below which there was a marked sensitivity of simulated fire severity to stand structure, and to interactions between intensity and structure. We found no evidence for a residual effect of pyrogeographic region on simulated severity, after the effects of stand structure and species composition were accounted for. The model presented here was able to produce variation in fire severity under a range of fire intensity conditions. This suggests that variation in stand structure is one of the factors causing the observed variation in boreal fire severity.

  9. Modelling Variable Fire Severity in Boreal Forests: Effects of Fire Intensity and Stand Structure

    PubMed Central

    Miquelajauregui, Yosune; Cumming, Steven G.; Gauthier, Sylvie

    2016-01-01

    It is becoming clear that fires in boreal forests are not uniformly stand-replacing. On the contrary, marked variation in fire severity, measured as tree mortality, has been found both within and among individual fires. It is important to understand the conditions under which this variation can arise. We integrated forest sample plot data, tree allometries and historical forest fire records within a diameter class-structured model of 1.0 ha patches of mono-specific black spruce and jack pine stands in northern Québec, Canada. The model accounts for crown fire initiation and vertical spread into the canopy. It uses empirical relations between fire intensity, scorch height, the percent of crown scorched and tree mortality to simulate fire severity, specifically the percent reduction in patch basal area due to fire-caused mortality. A random forest and a regression tree analysis of a large random sample of simulated fires were used to test for an effect of fireline intensity, stand structure, species composition and pyrogeographic regions on resultant severity. Severity increased with intensity and was lower for jack pine stands. The proportion of simulated fires that burned at high severity (e.g. >75% reduction in patch basal area) was 0.80 for black spruce and 0.11 for jack pine. We identified thresholds in intensity below which there was a marked sensitivity of simulated fire severity to stand structure, and to interactions between intensity and structure. We found no evidence for a residual effect of pyrogeographic region on simulated severity, after the effects of stand structure and species composition were accounted for. The model presented here was able to produce variation in fire severity under a range of fire intensity conditions. This suggests that variation in stand structure is one of the factors causing the observed variation in boreal fire severity. PMID:26919456

  10. Microbial Biomass Distribution and Compositional Changes Associated with a Warmer Climate in Boreal Forest Soils

    NASA Astrophysics Data System (ADS)

    Kohl, L.; Jérôme, J.; Billings, S. A.; Edwards, K.; Morrill, P. L.; Ziegler, S. E.

    2013-12-01

    Predicting the physiological and structural changes of the microbial community in warming soils is essential for a functional understanding of climate feedback mechanisms. Laboratory and field experiments have often found that warming increases soil organic carbon (SOC) mineralization and decreases microbial biomass, but remain more inconclusive regarding microbial community structure. These experiments, however, have been limited to responses on a time scale of months to years, while soil properties change over decades to centuries. Studies along climate gradients may prove helpful in elucidating how climate history affects soil properties, including microbial community structure. We present the phospholipid fatty acid (PLFA) based community characterization of the organic (L, F, H) and mineral (B; top 10cm) horizons of podzols from two mesic boreal forest sites similar in most aspects (e.g. stand type, class and age) but differing in mean annual temperature (MAT) by almost 6°C. This temperature difference is similar to the warming predicted for this region by 2100. Results are compared to respiration rates in laboratory incubations. We observed consistent PLFA derived biomass per unit SOC throughout the profile, independent of depth or site. The organic horizons contained similar amounts of SOC and PLFA as the top 10 cm of the mineral horizon (2.5-3.4 kg C m-2; 10.3-12.6 mmol PLFA m-2). Within the organic horizon, the greatest proportion of SOC and PLFA were found in the F horizon. The overall distribution of PLFA among the soil horizons was largely unaffected by climate regime, except that biomass was shifted from F to L horizons at the warmer site (from 12% to 29% of total organic horizon PLFA located in L) indicating that biomass was located closer to the surface in warmer sites. A similar shift was found in respiration (26 vs. 42% of organic horizon CO2 from L). As expected, community structure changed with depth. The abundance of fungal and protozoan PLFA

  11. Biomass burning in boreal forests and peatlands: Effects on ecosystem carbon losses and soil carbon stabilization as black carbon

    NASA Astrophysics Data System (ADS)

    Turetsky, M. R.; Kane, E. S.; Benscoter, B.

    2011-12-01

    Climate change has increased both annual area burned and the severity of biomass combustion in some boreal regions. For example, there has been a four-fold increase in late season fires in boreal Alaska over the last decade relative to the previous 50 years. Such changes in the fire regime are expected to stimulate ecosystem carbon losses through fuel combustion, reduced primary production, and increased decomposition. However, biomass burning also will influence the accumulation of black carbon in soils, which could promote long-term soil carbon sequestration. Variations in slope and aspect regulate soil temperatures and drainage conditions, and affect the development of permafrost and thick peat layers. Wet soil conditions in peatlands and permafrost forests often inhibit combustion during wildfires, leading to strong positive correlations between pre- and post- fire organic soil thickness that persist through multiple fire cycles. However, burning can occur in poorly drained ecosystems through smouldering combustion, which has implications for emission ratios of CO2:CH4:CO as well as black carbon formation. Our studies of combustion severity and black carbon concentrations in boreal soils show a negative relationship between concentrations of black carbon and organic carbon in soils post-fire. Relative to well drained stands, poorly drained sites with thick peat layers (such as north-facing stands) had less severe burning and low concentrations of black carbon in mineral soils post-fire. Conversely, drier forests lost a greater proportion of their organic soils during combustion but retained larger black carbon stocks following burning. Overall, we have quantified greater black carbon concentrations in surface mineral soil horizons than in organic soil horizons. This is surprising given that wildfires typically do not consume the entire organic soil layer in boreal forests, and could be indicative of the vulnerability of black carbon formed in organic horizons

  12. Predicting biomass of hyperdiverse and structurally complex Central Amazon forests - a virtual approach using extensive field data

    NASA Astrophysics Data System (ADS)

    Magnabosco Marra, D.; Higuchi, N.; Trumbore, S. E.; Ribeiro, G. H. P. M.; dos Santos, J.; Carneiro, V. M. C.; Lima, A. J. N.; Chambers, J. Q.; Negrón-Juárez, R. I.; Holzwarth, F.; Reu, B.; Wirth, C.

    2015-09-01

    Old-growth forests are subject to substantial changes in structure and species composition due to the intensification of human activities, gradual climate change and extreme weather events. Trees store ca. 90 % of the total AGB above-ground biomass in tropical forests and AGB estimation models are crucial for forest management and conservation. In the Central Amazon, predicting AGB at large spatial-scales is a challenging task due to the heterogeneity of successional stages, high tree species diversity and inherent variations in allometry and architecture. We parameterized generic AGB estimation models applicable across species and a wide range of structural and compositional variation related to species sorting into height layers as well as frequent natural disturbances. We used 727 trees from 101 genera and at least 135 species harvested in a contiguous forest near Manaus, Brazil. Sampling from this dataset we assembled six scenarios designed to span existing gradients in floristic composition and size distribution in order to select models that best predict AGB at the landscape-level across successional gradients. We found that good individual tree model fits do not necessarily translate into good predictions of AGB at the landscape level. When predicting AGB (dry mass) over scenarios using our different models and an available pantropical model, we observed systematic biases ranging from -31 % (pantropical) to +39 %, with RMSE root-mean-square error values of up to 130 Mg ha-1 (pantropical). Our first and second best models had both low mean biases (0.8 and 3.9 %, respectively) and RMSE (9.4 and 18.6 Mg ha-1) when applied over scenarios. Predicting biomass correctly at the landscape-level in complex tropical forests, especially allowing good performance at the margins of data availability for model parametrization, requires the inclusion of predictors related to species architecture. The model of interest should comprise the floristic composition and size

  13. Sensitivity of ERS-1 and JERS-1 radar data to biomass and stand structure in Alaskan boreal forest

    SciTech Connect

    Harrell, P.A.; Christensen, N.L. Jr.; Bourgeau-Chavez, L.L.; Kasischke, E.S.; French, N.H.F.

    1995-12-01

    As the boreal system is such an important component of the global carbon budget, it is important that the system and the potential changes be understood, whether from anthropogenic disturbances or global climate change. Thirty-two boreal forest sites were identified and sampled in the central region of Alaska to evaluate the sensitivity of the C-band ERS-1 and the L-band JERS-1 radar platforms to site biophysical properties. The sites selected represent black spruce (Picea mariana) and white spruce (Picea glauca) stands in a post-fire chronosequence. Black spruce biomass ranged from less than 1 kg/m{sup 2} to 5.6 kg/m{sup 2} and white spruce from 8.8 to 21.5 kg/m{sup 2}. Results indicate both ERS-1 and JERS-1 backscatter is responsive to biomass, density, and height, though other factors, principally surface moisture conditions, are often a stronger influence. Sensitivity to forest biomass and structure appears greatest when surface moisture conditions are minimized as a factor. Biomass correlations with the radar backscatter were strongest in the late winter imagery when all sites had a snow cover, and late summer when the surface is most dry. ERS-1 data may be more sensitive to surface moisture conditions than the JERS-1 data due to the shorter wavelength of the C-band sensor, though this is inconclusive because of limited JERS-1 L-band data for comparison.

  14. Life-cycle energy and GHG emissions of forest biomass harvest and transport for biofuel production in Michigan

    DOE PAGES

    Zhang, Fengli; Johnson, Dana M.; Wang, Jinjiang

    2015-04-01

    High dependence on imported oil has increased U.S. strategic vulnerability and prompted more research in the area of renewable energy production. Ethanol production from renewable woody biomass, which could be a substitute for gasoline, has seen increased interest. This study analysed energy use and greenhouse gas emission impacts on the forest biomass supply chain activities within the State of Michigan. A life-cycle assessment of harvesting and transportation stages was completed utilizing peer-reviewed literature. Results for forest-delivered ethanol were compared with those for petroleum gasoline using data specific to the U.S. The analysis from a woody biomass feedstock supply perspective uncoveredmore » that ethanol production is more environmentally friendly (about 62% less greenhouse gas emissions) compared with petroleum based fossil fuel production. Sensitivity analysis was conducted with key inputs associated with harvesting and transportation operations. The results showed that research focused on improving biomass recovery efficiency and truck fuel economy further reduced GHG emissions and energy consumption.« less

  15. Life-cycle energy and GHG emissions of forest biomass harvest and transport for biofuel production in Michigan

    SciTech Connect

    Zhang, Fengli; Johnson, Dana M.; Wang, Jinjiang

    2015-04-01

    High dependence on imported oil has increased U.S. strategic vulnerability and prompted more research in the area of renewable energy production. Ethanol production from renewable woody biomass, which could be a substitute for gasoline, has seen increased interest. This study analysed energy use and greenhouse gas emission impacts on the forest biomass supply chain activities within the State of Michigan. A life-cycle assessment of harvesting and transportation stages was completed utilizing peer-reviewed literature. Results for forest-delivered ethanol were compared with those for petroleum gasoline using data specific to the U.S. The analysis from a woody biomass feedstock supply perspective uncovered that ethanol production is more environmentally friendly (about 62% less greenhouse gas emissions) compared with petroleum based fossil fuel production. Sensitivity analysis was conducted with key inputs associated with harvesting and transportation operations. The results showed that research focused on improving biomass recovery efficiency and truck fuel economy further reduced GHG emissions and energy consumption.

  16. Mapping forest biomass from space - Fusion of hyperspectral EO1-hyperion data and Tandem-X and WorldView-2 canopy height models

    NASA Astrophysics Data System (ADS)

    Kattenborn, Teja; Maack, Joachim; Faßnacht, Fabian; Enßle, Fabian; Ermert, Jörg; Koch, Barbara

    2015-03-01

    Spaceborne sensors allow for wide-scale assessments of forest ecosystems. Combining the products of multiple sensors is hypothesized to improve the estimation of forest biomass. We applied interferometric (Tandem-X) and photogrammetric (WorldView-2) based predictors, e.g. canopy height models, in combination with hyperspectral predictors (EO1-Hyperion) by using 4 different machine learning algorithms for biomass estimation in temperate forest stands near Karlsruhe, Germany. An iterative model selection procedure was used to identify the optimal combination of predictors. The most accurate model (Random Forest) reached a r2 of 0.73 with a RMSE of 14.9% (29.4 t/ha). Further results revealed that the predictive accuracy depended highly on the statistical model and the area size of the field samples. We conclude that a fusion of canopy height and spectral information allows for accurate estimations of forest biomass from space.

  17. Are variations in heterotrophic soil respiration related to changes in substrate availability and microbial biomass carbon in the subtropical forests?

    NASA Astrophysics Data System (ADS)

    Wei, Hui; Chen, Xiaomei; Xiao, Guoliang; Guenet, Bertrand; Vicca, Sara; Shen, Weijun

    2015-12-01

    Soil temperature and moisture are widely-recognized controlling factors on heterotrophic soil respiration (Rh), although they often explain only a portion of Rh variability. How other soil physicochemical and microbial properties may contribute to Rh variability has been less studied. We conducted field measurements on Rh half-monthly and associated soil properties monthly for two years in four subtropical forests of southern China to assess influences of carbon availability and microbial properties on Rh. Rh in coniferous forest was significantly lower than that in the other three broadleaf species-dominated forests and exhibited obvious seasonal variations in the four forests (P < 0.05). Temperature was the primary factor influencing the seasonal variability of Rh while moisture was not in these humid subtropical forests. The quantity and decomposability of dissolved organic carbon (DOC) were significantly important to Rh variations, but the effect of DOC content on Rh was confounded with temperature, as revealed by partial mantel test. Microbial biomass carbon (MBC) was significantly related to Rh variations across forests during the warm season (P = 0.043). Our results suggest that DOC and MBC may be important when predicting Rh under some conditions, and highlight the complexity by mutual effects of them with environmental factors on Rh variations.

  18. Are variations in heterotrophic soil respiration related to changes in substrate availability and microbial biomass carbon in the subtropical forests?

    PubMed Central

    Wei, Hui; Chen, Xiaomei; Xiao, Guoliang; Guenet, Bertrand; Vicca, Sara; Shen, Weijun

    2015-01-01

    Soil temperature and moisture are widely-recognized controlling factors on heterotrophic soil respiration (Rh), although they often explain only a portion of Rh variability. How other soil physicochemical and microbial properties may contribute to Rh variability has been less studied. We conducted field measurements on Rh half-monthly and associated soil properties monthly for two years in four subtropical forests of southern China to assess influences of carbon availability and microbial properties on Rh. Rh in coniferous forest was significantly lower than that in the other three broadleaf species-dominated forests and exhibited obvious seasonal variations in the four forests (P < 0.05). Temperature was the primary factor influencing the seasonal variability of Rh while moisture was not in these humid subtropical forests. The quantity and decomposability of dissolved organic carbon (DOC) were significantly important to Rh variations, but the effect of DOC content on Rh was confounded with temperature, as revealed by partial mantel test. Microbial biomass carbon (MBC) was significantly related to Rh variations across forests during the warm season (P = 0.043). Our results suggest that DOC and MBC may be important when predicting Rh under some conditions, and highlight the complexity by mutual effects of them with environmental factors on Rh variations. PMID:26670822

  19. Predicting the responses of forest distribution and aboveground biomass to climate change under RCP scenarios in southern China.

    PubMed

    Dai, Erfu; Wu, Zhuo; Ge, Quansheng; Xi, Weimin; Wang, Xiaofan

    2016-11-01

    In the past three decades, our global climate has been experiencing unprecedented warming. This warming has and will continue to significantly influence the structure and function of forest ecosystems. While studies have been conducted to explore the possible responses of forest landscapes to future climate change, the representative concentration pathways (RCPs) scenarios under the framework of the Coupled Model Intercomparison Project Phase 5 (CMIP5) have not been widely used in quantitative modeling research of forest landscapes. We used LANDIS-II, a forest dynamic landscape model, coupled with a forest ecosystem process model (PnET-II), to simulate spatial interactions and ecological succession processes under RCP scenarios, RCP2.6, RCP4.5 and RCP8.5, respectively. We also modeled a control scenario of extrapolating current climate conditions to examine changes in distribution and aboveground biomass (AGB) among five different forest types for the period of 2010-2100 in Taihe County in southern China, where subtropical coniferous plantations dominate. The results of the simulation show that climate change will significantly influence forest distribution and AGB. (i) Evergreen broad-leaved forests will expand into Chinese fir and Chinese weeping cypress forests. The area percentages of evergreen broad-leaved forests under RCP2.6, RCP4.5, RCP8.5 and the control scenarios account for 18.25%, 18.71%, 18.85% and 17.46% of total forest area, respectively. (ii) The total AGB under RCP4.5 will reach its highest level by the year 2100. Compared with the control scenarios, the total AGB under RCP2.6, RCP4.5 and RCP8.5 increases by 24.1%, 64.2% and 29.8%, respectively. (iii) The forest total AGB increases rapidly at first and then decreases slowly on the temporal dimension. (iv) Even though the fluctuation patterns of total AGB will remain consistent under various future climatic scenarios, there will be certain responsive differences among various forest types.

  20. Influence of harvesting intensity on the floristic composition of natural Mediterranean maritime pine forest

    NASA Astrophysics Data System (ADS)

    Alday, Josu G.; Martínez-Ruiz, Carolina; Marrs, Rob H.; Bravo, Felipe

    2010-05-01

    Understorey plant species composition is an important part of forest ecosystems and its conservation is becoming an increasingly frequent objective in forest management plans. However, there is a lack of knowledge of the effect of timber harvesting on the characteristic understorey species in the Mediterranean region. We investigated the effects of three different harvest intensities on the short-term dynamics of understorey vegetation in a natural Maritime pine forest in Spain, and compared the results with uncut controls. Clear-cutting induced both qualitative and quantitative differences with respect to the controls, but intermediate levels of harvesting (25% and 50% removal) induced only quantitative differences. Harvesting reduced the frequency and cover of 56% of characteristic forest species, but only 22% showed an increase. Of the most abundant plant families only the Fabaceae showed a significant response with respect to harvesting intensity. Our findings suggest that Light- and Medium-harvest regimes are better management options than clear-cutting if the aim is to conserve the understorey vegetation.

  1. Critical loads and their exceedances at intensive forest monitoring sites in Europe.

    PubMed

    Lorenz, Martin; Nagel, Hans-Dieter; Granke, Oliver; Kraft, Philipp

    2008-10-01

    Intensive forest monitoring by means of harmonised methods has been conducted in Europe for more than a decade. Risks of atmospheric nitrogen and sulphur deposition are assessed by means of calculations of critical loads and their exceedances. In the present study throughfall and bulk deposition of nitrate (N-NO(3)), ammonium (N-NH(4)) and sulphate (S-SO(4)) show marked spatial patterns and temporal trends. In the period of observation (1999-2004), sulphate deposition on intensive monitoring plots decreased by about one quarter. This is in line with the reduction of S deposition by 70% since 1981 in Europe as a result of successful air pollution control politics under the Convention on Long-range Transboundary Air Pollution (CLRTAP). However, sulphate and especially nitrate and ammonium deposition were found to still exceed critical loads at many forest sites, indicating a continued need for further implementation of air pollution abatement strategies.

  2. Despite Buffers, Experimental Forest Clearcuts Impact Amphibian Body Size and Biomass.

    PubMed

    Veysey Powell, Jessica S; Babbitt, Kimberly J

    2015-01-01

    Forest buffers are a primary tool used to protect wetland-dependent wildlife. Though implemented widely, buffer efficacy is untested for most amphibian species. Consequently, it remains unclear whether buffers are sufficient for maintaining amphibian populations and if so, how wide buffers should be. We present evidence from a six-year, landscape-scale experiment testing the impacts of clearcutting, buffer width, and hydroperiod on body size and condition and biomass of breeding adults for two amphibian species at 11 vernal pools in the northeastern United States. We randomly assigned treatments (i.e., reference, 100m buffer, 30m buffer) across pools, clearcut to create buffers, and captured all spotted salamanders and wood frogs. Clearcuts strongly and negatively impacted size, condition, and biomass, but wider buffers mitigated effect magnitude and duration. Among recaptured individuals, for example, 30m-treatment salamanders were predicted to be about 9.5 mm shorter than, while 100m-treatment salamanders did not differ in length from, reference-treatment salamanders. Similarly, among recaptured frogs, mean length in the 30m treatment was predicted to decrease by about 1 mm/year, while in the 100m and reference treatments, length was time-invariant. Some, but not all, metrics recovered with time. For example, female new-captured and recaptured salamanders were predicted, respectively and on average, to weigh 4.5 and 7 g less in the 30m versus reference treatment right after the cut. While recaptured-female mass was predicted to recover by 9.5 years post-cut, new-captured-female mass did not recover. Hydroperiod was an important mediator: in the 100m treatment, cutting predominately affected pools that were stressed hydrologically. Overall, salamanders and female frogs were impacted more than male frogs. Our results highlight the importance of individualized metrics like body size, which can reveal sublethal effects and illuminate mechanisms by which habitat

  3. Despite Buffers, Experimental Forest Clearcuts Impact Amphibian Body Size and Biomass

    PubMed Central

    Veysey Powell, Jessica S.; Babbitt, Kimberly J.

    2015-01-01

    Forest buffers are a primary tool used to protect wetland-dependent wildlife. Though implemented widely, buffer efficacy is untested for most amphibian species. Consequently, it remains unclear whether buffers are sufficient for maintaining amphibian populations and if so, how wide buffers should be. We present evidence from a six-year, landscape-scale experiment testing the impacts of clearcutting, buffer width, and hydroperiod on body size and condition and biomass of breeding adults for two amphibian species at 11 vernal pools in the northeastern United States. We randomly assigned treatments (i.e., reference, 100m buffer, 30m buffer) across pools, clearcut to create buffers, and captured all spotted salamanders and wood frogs. Clearcuts strongly and negatively impacted size, condition, and biomass, but wider buffers mitigated effect magnitude and duration. Among recaptured individuals, for example, 30m-treatment salamanders were predicted to be about 9.5 mm shorter than, while 100m-treatment salamanders did not differ in length from, reference-treatment salamanders. Similarly, among recaptured frogs, mean length in the 30m treatment was predicted to decrease by about 1 mm/year, while in the 100m and reference treatments, length was time-invariant. Some, but not all, metrics recovered with time. For example, female new-captured and recaptured salamanders were predicted, respectively and on average, to weigh 4.5 and 7 g less in the 30m versus reference treatment right after the cut. While recaptured-female mass was predicted to recover by 9.5 years post-cut, new-captured-female mass did not recover. Hydroperiod was an important mediator: in the 100m treatment, cutting predominately affected pools that were stressed hydrologically. Overall, salamanders and female frogs were impacted more than male frogs. Our results highlight the importance of individualized metrics like body size, which can reveal sublethal effects and illuminate mechanisms by which habitat

  4. Biomass Energy Self-Sufficiency Resource Alternatives for a Forested Air Force Installation.

    DTIC Science & Technology

    1982-05-01

    to support basewide biomass energy systems. The study confirmed the feasibility of a biomass energy plantation supplying the required fuel wood to...support the basewide biomass energy systems while, at the same time not conflicting with any of the operational missions of Eglin AFB. This conclusion is...have an installation that provides all of its electrical and thermal energy requirements through the utilization of the Biomass Energy Island concept. (Author)

  5. Long-term structural and biomass dynamics of virgin Tsuga canadensis-Pinus strobus forests after hurricane disturbance.

    PubMed

    D'Amato, Anthony W; Orwig, David A; Foster, David R; Barker Plotkin, Audrey; Schoonmaker, Peter K; Wagner, Maggie R

    2017-03-01

    The development of old-growth forests in northeastern North America has largely been within the context of gap-scale disturbances given the rarity of stand-replacing disturbances. Using the 10-ha old-growth Harvard Tract and its associated 90-year history of measurements, including detailed surveys in 1989 and 2009, we document the long-term structural and biomass development of an old-growth Tsuga canadensis-Pinus strobus forest in southern New Hampshire, USA following a stand-replacing hurricane in 1938. Measurements of aboveground biomass pools were integrated with data from second- and old-growth T. canadensis forests to evaluate long-term patterns in biomass development following this disturbance. Ecosystem structure across the Tract prior to the hurricane exhibited a high degree of spatial heterogeneity with the greatest levels of live tree basal area (70-129 m(2) /ha) on upper west-facing slopes where P. strobus was dominant and intermixed with T. canadensis. Live-tree biomass estimates for these stratified mixtures ranged from 159 to 503 Mg/ha at the localized, plot scale (100 m(2) ) and averaged 367 Mg/ha across these portions of the landscape approaching the upper bounds for eastern forests. Live-tree biomass 71 years after the hurricane is more uniform and lower in magnitude, with T. canadensis currently the dominant overstory tree species throughout much of the landscape. Despite only one living P. strobus stem in the 2009 plots (and fewer than five stems known across the entire 10-ha area), the detrital legacy of this species is pronounced with localized accumulations of coarse woody debris exceeding 237.7-404.2 m(3) /ha where this species once dominated the canopy. These patterns underscore the great sizes P. strobus attained in pre-European landscapes and its great decay resistance relative to its forest associates. Total aboveground biomass pools in this 71-year-old forest (255 Mg/ha) are comparable to those in modern old

  6. Estimation of Regional Forest Aboveground Biomass Combining Icesat-Glas Waveforms and HJ-1A/HSI Hyperspectral Imageries

    NASA Astrophysics Data System (ADS)

    Xing, Yanqiu; Qiu, Sai; Ding, Jianhua; Tian, Jing

    2016-06-01

    Estimation of forest aboveground biomass (AGB) is a critical challenge for understanding the global carbon cycle because it dominates the dynamics of the terrestrial carbon cycle. Light Detection and Ranging (LiDAR) system has a unique capability for estimating accurately forest canopy height, which has a direct relationship and can provide better understanding to the forest AGB. The Geoscience Laser Altimeter System (GLAS) onboard the Ice, Cloud, and land Elevation Satellite (ICESat) is the first polarorbiting LiDAR instrument for global observations of Earth, and it has been widely used for extracting forest AGB with footprints of nominally 70 m in diameter on the earth's surface. However, the GLAS footprints are discrete geographically, and thus it has been restricted to produce the regional full coverage of forest AGB. To overcome the limit of discontinuity, the Hyper Spectral Imager (HSI) of HJ-1A with 115 bands was combined with GLAS waveforms to predict the regional forest AGB in the study. Corresponding with the field investigation in Wangqing of Changbai Mountain, China, the GLAS waveform metrics were derived and employed to establish the AGB model, which was used further for estimating the AGB within GLAS footprints. For HSI imagery, the Minimum Noise Fraction (MNF) method was used to decrease noise and reduce the dimensionality of spectral bands, and consequently the first three of MNF were able to offer almost 98% spectral information and qualified to regress with the GLAS estimated AGB. Afterwards, the support vector regression (SVR) method was employed in the study to establish the relationship between GLAS estimated AGB and three of HSI MNF (i.e. MNF1, MNF2 and MNF3), and accordingly the full covered regional forest AGB map was produced. The results showed that the adj.R2 and RMSE of SVR-AGB models were 0.75 and 4.68 t hm-2 for broadleaf forests, 0.73 and 5.39 t hm-2 for coniferous forests and 0.71 and 6.15 t hm-2 for mixed forests respectively. The

  7. A Comparison of Two Above-Ground Biomass Estimation Techniques Integrating Satellite-Based Remotely Sensed Data and Ground Data for Tropical and Semiarid Forests in Puerto Rico

    EPA Science Inventory

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

  8. Comparative study for hardwood and softwood forest biomass: chemical characterization, combustion phases and gas and particulate matter emissions.

    PubMed

    Amaral, Simone Simões; de Carvalho, João Andrade; Costa, Maria Angélica Martins; Soares Neto, Turíbio Gomes; Dellani, Rafael; Leite, Luiz Henrique Scavacini

    2014-07-01

    Two different types of typical Brazilian forest biomass were burned in the laboratory in order to compare their combustion characteristics and pollutant emissions. Approximately 2 kg of Amazon biomass (hardwood) and 2 kg of Araucaria biomass (softwood) were burned. Gaseous emissions of CO2, CO, and NOx and particulate matter smaller than 2.5 μm (PM2.5) were evaluated in the flaming and smoldering combustion phases. Temperature, burn rate, modified combustion efficiency, emissions factor, and particle diameter and concentration were studied. A continuous analyzer was used to quantify gas concentrations. A DataRam4 and a Cascade Impactor were used to sample PM2.5. Araucaria biomass (softwood) had a lignin content of 34.9%, higher than the 23.3% of the Amazon biomass (hardwood). CO2 and CO emissions factors seem to be influenced by lignin content. Maximum concentrations of CO2, NOx and PM2.5 were observed in the flaming phase.

  9. Forest lepidopteran communities are more resilient to shelterwood harvests compared to more intensive logging regimes.

    PubMed

    Summerville, Keith S

    2013-07-01

    A common measure of ecosystem resilience is the time course to recovery for a system that has been previously disturbed. The goal of this study was to assess whether forest lepidopteran communities displayed three different forms of resilience following experimental timber harvest. Specifically, I examined whether moth species assemblages returned to pre-logging composition (compositional resilience), species richness (structural resilience), and guild diversity (functional resilience) after forest management. Lepidoptera were sampled from 16 forest stands managed with one of four harvest treatments: no logging, clear-cutting, shelterwood harvests, and group selection harvests. Moths were sampled from all forest stands one year prior to harvest in 2007 and immediately postharvest in 2009-2011. Moth community composition only appeared to be resilient to timber harvest in stands managed with shelterwood methods (15% biomass removed) or in the unlogged stands within managed concession units. Both total species richness and species richness of Quercus-feeding moths also appeared to recover to a near original condition three years post-shelterwood logging. In contrast, moth assemblages in clear-cut stands and group selection stands (80% biomass removed) remained impoverished. Tests of functional resilience suggested that richness of species known to be pollinators was largely unaffected by timber management, and the number of moth species known to feed on herbaceous vegetation doubled in stands logged using group selection methods. Dietary specialists were disproportionately abundant in the unlogged stands postharvest, suggesting that species with more narrow dietary niches have the lowest resilience to timber management. These results suggest that most methods of forest management have short-term negative impacts on woody-plant-feeding Lepidoptera, but that the effects are limited to a few years when the harvest method involves shelterwood cuts. Herbaceous

  10. [Effects of precipitation variation on growing seasonal dynamics of soil microbial biomass in broadleaved Korean pine mixed forest].

    PubMed

    Wang, Ning; Wang, Mei-ju; Li, Shi-lan; Wang, Nan-nan; Feng, Fu-juan; Han, Shi-jie

    2015-05-01

    Broadleaved Korean pine mixed forest is the zonal climax vegetation in Northeast China and it plays a significant role in maintaining the ecological security. Changbai Mountains is a suitable region to study the positive and negative feedback mechanisms of temperate forest for precipitation variation. This study analyzed responses of soil microbial biomass carbon (SMBC) and microbial biomass nitrogen (SMBN) to precipitation variation (± 30%) in original broadleaved Korean pine mixed forest of Changbai Mountains. The results showed that, during the growing seasons (from May to September), the averages of SMBC and SMBN were 879.09 and 100.03 mg · kg(-1), respectively. Moreover, both of these two parameters gradually decreased with the soil depth. The contents of SMBC and SMBN all increased with the increasing precipitation, and the changes of SMBC and SMBN in the 0-5 cm soil layer were stronger than in the 5-10 cm soil layer. The value of SMBC/SMBN declined with the increase of precipitation. The precipitation variation significantly influenced the means of SMBC and SMBN. Compared with precipitation reduction, precipitation enhancement affected the indices much significantly. Both SMBC and SMBN showed similar seasonal patterns, which were the lowest in May, and after that, they increased and then decreased and increased again, showing 1-2 peaks in the growing season. However, the value and occurring time of the peaks varied with the precipitation and soil layer, and the seasonal variations of SMBC and SMBN in the 0-5 cm soil layer were higher than in the 5-10 cm soil layer. SMBC and SMBN had significant positive correlation with organic matter and total nitrogen content. The variances of soil physical and chemical properties caused by precipitation variation were closely related with the difference in spatial-temporal patterns of the soil microbial biomass in the forest. In conclusion, the precipitation variations could cause the change of the soil microbial

  11. Charcoal reflectance reveals early holocene boreal deciduous forests burned at high intensities.

    PubMed

    Hudspith, Victoria A; Belcher, Claire M; Kelly, Ryan; Hu, Feng Sheng

    2015-01-01

    Wildfire size, frequency, and severity are increasing in the Alaskan boreal forest in response to climate warming. One of the potential impacts of this changing fire regime is the alteration of successional trajectories, from black spruce to mixed stands dominated by aspen, a vegetation composition not experienced since the early Holocene. Such changes in vegetation composition may consequently alter the intensity of fires, influencing fire feedbacks to the ecosystem. Paleorecords document past wildfire-vegetation dynamics and as such, are imperative for our understanding of how these ecosystems will respond to future climate warming. For the first time, we have used reflectance measurements of macroscopic charcoal particles (>180μm) from an Alaskan lake-sediment record to estimate ancient charring temperatures (termed pyrolysis intensity). We demonstrate that pyrolysis intensity increased markedly from an interval of birch tundra 11 ky ago (mean 1.52%Ro; 485°C), to the expansion of trees on the landscape ~10.5 ky ago, remaining high to the present (mean 3.54%Ro; 640°C) irrespective of stand composition. Despite differing flammabilities and adaptations to fire, the highest pyrolysis intensities derive from two intervals with distinct vegetation compositions. 1) the expansion of mixed aspen and spruce woodland at 10 cal. kyr BP, and 2) the establishment of black spruce, and the modern boreal forest at 4 cal. kyr BP. Based on our analysis, we infer that predicted expansion of deciduous trees into the boreal forest in the future could lead to high intensity, but low severity fires, potentially moderating future climate-fire feedbacks.

  12. Charcoal Reflectance Reveals Early Holocene Boreal Deciduous Forests Burned at High Intensities

    PubMed Central

    Hudspith, Victoria A.; Belcher, Claire M.; Kelly, Ryan; Hu, Feng Sheng

    2015-01-01

    Wildfire size, frequency, and severity are increasing in the Alaskan boreal forest in response to climate warming. One of the potential impacts of this changing fire regime is the alteration of successional trajectories, from black spruce to mixed stands dominated by aspen, a vegetation composition not experienced since the early Holocene. Such changes in vegetation composition may consequently alter the intensity of fires, influencing fire feedbacks to the ecosystem. Paleorecords document past wildfire-vegetation dynamics and as such, are imperative for our understanding of how these ecosystems will respond to future climate warming. For the first time, we have used reflectance measurements of macroscopic charcoal particles (>180μm) from an Alaskan lake-sediment record to estimate ancient charring temperatures (termed pyrolysis intensity). We demonstrate that pyrolysis intensity increased markedly from an interval of birch tundra 11 ky ago (mean 1.52%Ro; 485°C), to the expansion of trees on the landscape ∼10.5 ky ago, remaining high to the present (mean 3.54%Ro; 640°C) irrespective of stand composition. Despite differing flammabilities and adaptations to fire, the highest pyrolysis intensities derive from two intervals with distinct vegetation compositions. 1) the expansion of mixed aspen and spruce woodland at 10 cal. kyr BP, and 2) the establishment of black spruce, and the modern boreal forest at 4 cal. kyr BP. Based on our analysis, we infer that predicted expansion of deciduous trees into the boreal forest in the future could lead to high intensity, but low severity fires, potentially moderating future climate-fire feedbacks. PMID:25853712

  13. Impact of torrefaction on the grindability and fuel characteristics of forest biomass.

    PubMed

    Phanphanich, Manunya; Mani, Sudhagar

    2011-01-01

    Thermal pretreatment or torrefaction of biomass under anoxic condition can produce an energy dense and consistent quality solid biomass fuel for combustion and co-firing applications. This paper investigates the fuel characteristics and grindability of pine chips and logging residues torrefied at temperatures ranging from 225 °C to 300 °C and 30 min residence time. Grinding performance of torrefied biomass evaluated by determining energy required for grinding, particle size distribution and average particle size were compared with raw biomass and coal. Specific energy required for grinding of torrefied biomass decreased significantly with increase in torrefaction temperatures. The grinding energy of torrefied biomass was reduced to as low as 24 kW h/t at 300 °C torrefaction temperature. The gross calorific value of torrefied chips increased with increase in torrefaction temperature. Torrefaction of biomass clearly showed the improved fuel characteristics and grinding properties closer to coal.

  14. Impacts of Sample Design on Estimation of Aboveground Biomass: Implications for the Assimilation of Lidar and Forest Inventory Data

    NASA Astrophysics Data System (ADS)

    Duffy, P.; Keller, M. M.; Morton, D. C.; Schimel, D.

    2015-12-01

    The availability of lidar data that can be used to characterize forest structure and estimate aboveground biomass (AGB) is rapidly increasing. When lidar data are considered in conjunction with forest inventory data to estimate AGB, the order of acquisition for these data products may impact the quality of the resulting estimates. In this work, we address this question in the context of uncertainty reduction with respect to estimation of AGB in a degraded forest in Paragominas, Brazil. We have developed a simulation framework that quantitatively assesses the uncertainty associated with estimation of AGB for different sampling strategies that combine forest inventory and lidar data. We utilize a Bayesian hierarchical modeling (BHM) data assimilation framework to combine information from the forest inventory and lidar data products into a higher order data product of AGB. Spatially explicit realizations of AGB are generated under different sampling strategies. Sampling strategies are assessed using the distributional properties of the assimilated higher order data product in the context of uncertainty reduction. We consider both spatially explicit maps of uncertainty as well as the standard deviation of the posterior predictive distributions of AGB as endpoints for the quantification of uncertainty. This framework allows for the explicit characterization of important sources of uncertainty. Our results show that a significant reduction in the uncertainty associated with estimation of AGB can be realized when design optimization is utilized in this context.

  15. Stemflow amount, intensity and timing in a mature forest in coastal British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    van Meerveld, Ilja; Spencer, Sheena

    2013-04-01

    Stemflow is the portion of precipitation that falls on the forest canopy and flows along tree branches and stems to the soil at the base of the tree. Previous studies have shown the importance of stemflow for nutrient cycling, groundwater recharge, plant water uptake and soil moisture dynamics; however little is known about stemflow in mature coastal British Columbia forests. Furthermore, most studies focus on the amount of stemflow; few studies have looked at the timing or intensity of stemflow relative to precipitation intensity. We therefore measured stemflow from 18 trees of four different species within a ~1 ha mature western hemlock-western redcedar stand within the Malcolm Knapp Research Forest in British Columbia, Canada, using water collecting containers and tipping bucket rain gauges. Measurements between February and November 2010 showed that stemflow amount was highly variable between the different trees. It did not vary much between species but instead varied mainly with tree size. Trees smaller than 35 cm in diameter contributed relatively more stemflow than larger trees; they represented 24% of the total basal area but contributed ~72% of total stemflow at this site. Funneling ratios were larger than one for the trees smaller than 35 cm in diameter and increased with event size up to 50 mm. Funneling ratios for larger trees were less than one and did not vary much with event size. Stemflow started on average after 3 mm of precipitation. Peak stemflow intensities were much larger than peak precipitation intensity for some events and did not always occur at the same time as peak precipitation intensity; peak stemflow intensities tended to increase for consecutive precipitation bursts and occurred approximately 15 minutes after the corresponding peak precipitation intensity. Peak stemflow intensities were not related to tree species or tree size. Even though stemflow accounted for only ~1% of precipitation, high peak stemflow intensities could

  16. Closing a gap in tropical forest biomass estimation: taking crown mass variation into account in pantropical allometries

    NASA Astrophysics Data System (ADS)

    Ploton, Pierre; Barbier, Nicolas; Takoudjou Momo, Stéphane; Réjou-Méchain, Maxime; Boyemba Bosela, Faustin; Chuyong, Georges; Dauby, Gilles; Droissart, Vincent; Fayolle, Adeline; Calisto Goodman, Rosa; Henry, Matieu; Kamdem, Narcisse Guy; Katembo Mukirania, John; Kenfack, David; Libalah, Moses; Ngomanda, Alfred; Rossi, Vivien; Sonké, Bonaventure; Texier, Nicolas; Thomas, Duncan; Zebaze, Donatien; Couteron, Pierre; Berger, Uta; Pélissier, Raphaël

    2016-03-01

    Accurately monitoring tropical forest carbon stocks is a challenge that remains outstanding. Allometric models that consider tree diameter, height and wood density as predictors are currently used in most tropical forest carbon studies. In particular, a pantropical biomass model has been widely used for approximately a decade, and its most recent version will certainly constitute a reference model in the coming years. However, this reference model shows a systematic bias towards the largest trees. Because large trees are key drivers of forest carbon stocks and dynamics, understanding the origin and the consequences of this bias is of utmost concern. In this study, we compiled a unique tree mass data set of 673 trees destructively sampled in five tropical countries (101 trees > 100 cm in diameter) and an original data set of 130 forest plots (1 ha) from central Africa to quantify the prediction error of biomass allometric models at the individual and plot levels when explicitly taking crown mass variations into account or not doing so. We first showed that the proportion of crown to total tree aboveground biomass is highly variable among trees, ranging from 3 to 88 %. This proportion was constant on average for trees < 10 Mg (mean of 34 %) but, above this threshold, increased sharply with tree mass and exceeded 50 % on average for trees ≥ 45 Mg. This increase coincided with a progressive deviation between the pantropical biomass model estimations and actual tree mass. Taking a crown mass proxy into account in a newly developed model consistently removed the bias observed for large trees (> 1 Mg) and reduced the range of plot-level error (in %) from [-23; 16] to [0; 10]. The disproportionally higher allocation of large trees to crown mass may thus explain the bias observed recently in the reference pantropical model. This bias leads to far-from-negligible, but often overlooked, systematic errors at the plot level and may be easily corrected by taking a crown mass

  17. Impact of anthropogenic and climatic changes on biomass and diversity of the Central African forests, from local to global scale: original methods for new results

    NASA Astrophysics Data System (ADS)

    Mortier, Frédéric; Gourlet-Fleury, Sylvie; Ouédraogo, Dakis; Picard, Nicolas; Rossi, Vivien

    2014-05-01

    Forests of the Congo Basin, the second most important remaining block of tropical moist forest in the world, are facing increasing anthropogenic pressure and climate change. Understanding the biomass and diversity dynamics under these pressures is one major challenge for African nations and international communities. This talk aims to present original methods to model, infer, and predict growth, biomass and diversity of Central African forests, as well as new results on the impacts of global change on those forests, at various scales. With respect to methods, we will present theoretical frameworks allowing (i) to model growth processes in species-rich ecosystems like tropical rain forests, (ii) to take into account uncertainties in biomass estimation. In terms of results, we will highlight at a local scale, how human activities as well as climatic variations would impact (i) the composition and diversity of forests, (ii) the dynamics of biomass and growth processes. At a global scale, we will demonstrate how environmental filtering controls the above ground biomass. The number of studies are currently increasing over the Congo Basin through several research projects led by our team (CoForTips, DynAfFor) and contributing to various international organization's programs (Cifor, FAO, Comifac, Ofac).

  18. Assessing Biomass Carbon Stocks Over Tropical Peat Swamp Forests Using Multi-Temporal L-Band SAR Data

    NASA Astrophysics Data System (ADS)

    Wijaya, Arief; Liesenberg, Veraldo; Susanti, Ari; Karyanto, Oka; Verchot, Louis V.

    2013-12-01

    Peatland ecosystem has an important role as a carbon sink that stores huge amounts of carbon. This work focuses on biomass modelling applying multi-temporal SAR data over a tropical peat swamp forest in Indonesia. Four scenes of quad-polarimetric SAR(PLR) data from ALOS satellite are used for the study. The SAR data were acquired in April 2007, May 2007, April 2009 and April 2010. Attempts to estimate carbon stocks applied mono-temporal and multi-temporal approaches (e.g HHt1 vs HHt2, etc), also combining different polarizations (e.g HHt1+HVt1+VHt1+VVt1 vs HHt2+HVt2+VHt2+VVt2). Polarimetric features are supplied into the biomass equations to study their effects to the model performance. The findings show that co-polarization bands (HH and VV) in general are better than cross-polarization data (HV and VH) to predict biomass and several other forest stand parameters (i.e. LAI, tree height, diameter and basal area). Addition of polarimetric SAR features, e.g. Alpha angle, Entropy and Anisotropy have improved the empirical models predictability.

  19. Forest aboveground biomass estimation in Zhejiang Province using the integration of Landsat TM and ALOS PALSAR data

    NASA Astrophysics Data System (ADS)

    Zhao, Panpan; Lu, Dengsheng; Wang, Guangxing; Liu, Lijuan; Li, Dengqiu; Zhu, Jinru; Yu, Shuquan

    2016-12-01

    In remote sensing-based forest aboveground biomass (AGB) estimation research, data saturation in Landsat and radar data is well known, but how to reduce this problem for improving AGB estimation has not been fully examined. Different vegetation types have their own species composition and stand structure, thus they have different data saturation values in Landsat or radar data. Optical and radar data also have different characteristics in representing forest stand structures, thus effective use of their features may improve AGB estimation. This research examines the effects of Landsat Thematic Mapper (TM) and ALOS PALSAR L-band data and their integrations in forest AGB estimation of Zhejiang Province, China, and the roles of textural images from both datasets. The linear regression models of AGB were conducted by using (1) Landsat TM alone, (2) ALOS PALSAR data alone, (3) their combination as extra bands, and (4) their data fusion, based on non-stratification and stratification of vegetation types, respectively. The results show that (1) overall, Landsat TM data perform better than PALSAR data, but the latter can produce more accurate estimates for bamboo and shrub, and for forests with AGB values less than 60 Mg/ha; (2) the combination of TM and PALSAR data as extra bands can greatly improve AGB estimation performance, but their fusion using the modified high-pass filter resolution-merging technique cannot; (3) textures are indeed valuable in AGB estimation, especially for forests with complex stand structures such as mixed forests and pine forests with understories of broadleaf species; (4) stratification of vegetation types can improve AGB estimation performance; and (5) the results from the linear regression models are characterized by overestimation and underestimation for the smaller and larger AGB values, respectively, and thus, selecting non-linear models or non-parametric algorithms may be needed in future research.

  20. The stage-classified matrix models project a significant increase in biomass carbon stocks in China’s forests between 2005 and 2050

    PubMed Central

    Hu, Huifeng; Wang, Shaopeng; Guo, Zhaodi; Xu, Bing; Fang, Jingyun

    2015-01-01

    China’s forests are characterized by young age, low carbon (C) density and a large plantation area, implying a high potential for increasing C sinks in the future. Using data of provincial forest area and biomass C density from China’s forest inventories between 1994 and 2008 and the planned forest coverage of the country by 2050, we developed a stage-classified matrix model to predict biomass C stocks of China’s forests from 2005 to 2050. The results showed that total forest biomass C stock would increase from 6.43 Pg C (1 Pg = 1015 g) in 2005 to 9.97 Pg C (95% confidence interval: 8.98 ~ 11.07 Pg C) in 2050, with an overall net C gain of 78.8 Tg C yr−1 (56.7 ~ 103.3 Tg C yr−1; 1 Tg = 1012 g). Our findings suggest that China’s forests will be a large and persistent biomass C sink through 2050. PMID:26110831

  1. Raccoon (Procyon lotor) diurnal den use within an intensively managed forest in central West Virginia

    USGS Publications Warehouse

    Owen, Sheldon F.; Berl, Jacob L.; Edwards, John W.; Ford, W. Mark; Wood, Petra Bohall

    2015-01-01

    Intensive forest management may influence the availability of suitable den sites for large den-seeking species, such as Procyon lotor (Raccoon). As part of a Raccoon ecology study on an industrial forest in the Allegheny Mountains of central West Virginia, we radio-tracked 32 Raccoons to 175 diurnal den sites to determine relative use of dens that included cavity trees, rock dens, log piles, slash piles, and exposed limbs. Patterns of den use significantly differed between sexes and among seasons. Overall, we recorded 58 cavity dens in 12 tree species with 7 maternal dens found in 5 tree species. Raccoons selected larger-diameter den trees than available cavity trees and non-cavity trees. Because the abundance of suitable tree cavities is known to influence Raccoon densities and recruitment at fine spatial scales and female Raccoons in this study used tree cavities as maternal den sites, the continued harvest of large-diameter trees (i.e., those capable of developing den cavities) without replacement may impact Raccoon recruitment within intensively managed forests throughout the central Appalachians.

  2. Estimating aboveground biomass for broadleaf woody plants and young conifers in Sierra Nevada, California forests.

    USGS Publications Warehouse

    McGinnis, Thomas W.; Shook, Christine D.; Keeley, Jon E.

    2010-01-01

    Quantification of biomass is fundamental to a wide range of research and natural resource management goals. An accurate estimation of plant biomass is essential to predict potential fire behavior, calculate carbon sequestration for global climate change research, assess critical wildlife habitat, and so forth. Reliable allometric equations from simple field measurements are necessary for efficient evaluation of plant biomass. However, allometric equations are not available for many common woody plant taxa in the Sierra Nevada. In this report, we present more than 200 regression equations for the Sierra Nevada western slope that relate crown diameter, plant height, crown volume, stem diameter, and both crown diameter and height to the dry weight of foliage, branches, and entire aboveground biomass. Destructive sampling methods resulted in regression equations that accurately predict biomass from one or two simple, nondestructive field measurements. The tables presented here will allow researchers and natural resource managers to easily choose the best equations to fit their biomass assessment needs.

  3. Estimating aboveground biomass for broadleaf woody plants and young conifers in Sierra Nevada, California, forests

    USGS Publications Warehouse

    McGinnis, T.W.; Shook, C.D.; Keeley, J.E.

    2010-01-01

    Quantification of biomass is fundamental to a wide range of research and natural resource management goals. An accurate estimation of plant biomass is essential to predict potential fire behavior, calculate carbon sequestration for global climate change research, assess critical wildlife habitat, and so forth. Reliable allometric equations from simple field measurements are necessary for efficient evaluation of plant biomass. However, allometric equations are not available for many common woody plant taxa in the Sierra Nevada. In this report, we present more than 200 regression equations for the Sierra Nevada western slope that relate crown diameter, plant height, crown volume, stem diameter, and both crown diameter and height to the dry weight of foliage, branches, and entire aboveground biomass. Destructive sampling methods resulted in regression equations that accurately predict biomass from one or two simple, nondestructive field measurements. The tables presented here will allow researchers and natural resource managers to easily choose the best equations to fit their biomass assessment needs.

  4. Global Forest Canopy Height Maps Validation and Calibration for The Potential of Forest Biomass Estimation in The Southern United States

    NASA Astrophysics Data System (ADS)

    Ku, N. W.; Popescu, S. C.

    2015-12-01

    In the past few years, three global forest canopy height maps have been released. Lefsky (2010) first utilized the Geoscience Laser Altimeter System (GLAS) on the Ice, Cloud and land Elevation Satellite (ICESat) and Moderate Resolution Imaging Spectroradiometer (MODIS) data to generate a global forest canopy height map in 2010. Simard et al. (2011) integrated GLAS data and other ancillary variables, such as MODIS, Shuttle Radar Topography Mission (STRM), and climatic data, to generate another global forest canopy height map in 2011. Los et al. (2012) also used GLAS data to create a vegetation height map in 2012.Several studies attempted to compare these global height maps to other sources of data., Bolton et al. (2013) concluded that Simard's forest canopy height map has strong agreement with airborne lidar derived heights. Los map is a coarse spatial resolution vegetation height map with a 0.5 decimal degrees horizontal resolution, around 50 km in the US, which is not feasible for the purpose of our research. Thus, Simard's global forest canopy height map is the primary map for this research study. The main objectives of this research were to validate and calibrate Simard's map with airborne lidar data and other ancillary variables in the southern United States. The airborne lidar data was collected between 2010 and 2012 from: (1) NASA LiDAR, Hyperspectral & Thermal Image (G-LiHT) program; (2) National Ecological Observatory Network's (NEON) prototype data sharing program; (3) NSF Open Topography Facility; and (4) the Department of Ecosystem Science and Management at Texas A&M University. The airborne lidar study areas also cover a wide variety of vegetation types across the southern US. The airborne lidar data is post-processed to generate lidar-derived metrics and assigned to four different classes of point cloud data. The four classes of point cloud data are the data with ground points, above 1 m, above 3 m, and above 5 m. The root mean square error (RMSE) and

  5. Converting wood volume to biomass for pinyon and juniper. Forest Service research note

    SciTech Connect

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

    1993-03-01

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

  6. Novel and Lost Forests in the Upper Midwestern United States, from New Estimates of Settlement-Era Composition, Stem Density, and Biomass

    PubMed Central

    Mladenoff, David J.; Cogbill, Charles V.; Record, Sydne; Paciorek, Christopher J.; Jackson, Stephen T.; Dietze, Michael C.; Dawson, Andria; Matthes, Jaclyn Hatala; McLachlan, Jason S.; Williams, John W.

    2016-01-01

    Background EuroAmerican land-use and its legacies have transformed forest structure and composition across the United States (US). More accurate reconstructions of historical states are critical to understanding the processes governing past, current, and future forest dynamics. Here we present new gridded (8x8km) reconstructions of pre-settlement (1800s) forest composition and structure from the upper Midwestern US (Minnesota, Wisconsin, and most of Michigan), using 19th Century Public Land Survey System (PLSS), with estimates of relative composition, above-ground biomass, stem density, and basal area for 28 tree types. This mapping is more robust than past efforts, using spatially varying correction factors to accommodate sampling design, azimuthal censoring, and biases in tree selection. Changes in Forest Structure We compare pre-settlement to modern forests using US Forest Service Forest Inventory and Analysis (FIA) data to show the prevalence of lost forests (pre-settlement forests with no current analog), and novel forests (modern forests with no past analogs). Differences between pre-settlement and modern forests are spatially structured owing to differences in land-use impacts and accompanying ecological responses. Modern forests are more homogeneous, and ecotonal gradients are more diffuse today than in the past. Novel forest assemblages represent 28% of all FIA cells, and 28% of pre-settlement forests no longer exist in a modern context. Lost forests include tamarack forests in northeastern Minnesota, hemlock and cedar dominated forests in north-central Wisconsin and along the Upper Peninsula of Michigan, and elm, oak, basswood and ironwood forests along the forest-prairie boundary in south central Minnesota and eastern Wisconsin. Novel FIA forest assemblages are distributed evenly across the region, but novelty shows a strong relationship to spatial distance from remnant forests in the upper Midwest, with novelty predicted at between 20 to 60km from

  7. Distribution of biomass and nutrients in lodgepole pine/bitterbrush ecosystems in central Oregon. Forest Service research paper

    SciTech Connect

    Little, S.N.; Shainsky, L.J.

    1992-09-01

    The authors investigated the distribution of biomass and nutrients in lodgepole pine (Pinus contorta var. murryana Dougl.) ecosystems on pumice soils in south-central Oregon. Sixty-three trees were sampled to develop equations for estimating dry weights of tree crowns, boles, bark, and coarse roots from diameter at breast height and height. The concentrations of total carbon, nitrogen, phosphorus, and sulfur were determined for each of these components. Biomass, nutrient concentrations, and nutrient contents of the associated vegetation, forest floor, woody debris, fine roots, and soil horizons also were determined. An example stand illustrates the use of these data for determining the effects of bole versus whole-tree harvesting on nutrient capital in a lodgepole pine ecosystem.

  8. Towards ground-truthing of spaceborne estimates of above-ground biomass and leaf area index in tropical rain forests

    NASA Astrophysics Data System (ADS)

    Köhler, P.; Huth, A.

    2010-05-01

    The canopy height of forests is a key variable which can be obtained using air- or spaceborne remote sensing techniques such as radar interferometry or lidar. If new allometric relationships between canopy height and the biomass stored in the vegetation can be established this would offer the possibility for a global monitoring of the above-ground carbon content on land. In the absence of adequate field data we use simulation results of a tropical rain forest growth model to propose what degree of information might be generated from canopy height and thus to enable ground-truthing of potential future satellite observations. We here analyse the correlation between canopy height in a tropical rain forest with other structural characteristics, such as above-ground biomass (AGB) (and thus carbon content of vegetation) and leaf area index (LAI). The process-based forest growth model FORMIND2.0 was applied to simulate (a) undisturbed forest growth and (b) a wide range of possible disturbance regimes typically for local tree logging conditions for a tropical rain forest site on Borneo (Sabah, Malaysia) in South-East Asia. It is found that for undisturbed forest and a variety of disturbed forests situations AGB can be expressed as a power-law function of canopy height h (AGB=a·hb) with an r2~60% for a spatial resolution of 20 m×20 m (0.04 ha, also called plot size). The regression is becoming significant better for the hectare wide analysis of the disturbed forest sites (r2=91%). There seems to exist no functional dependency between LAI and canopy height, but there is also a linear correlation (r2~60%) between AGB and the area fraction in which the canopy is highly disturbed. A reasonable agreement of our results with observations is obtained from a comparison of the simulations with permanent sampling plot data from the same region and with the large-scale forest inventory in Lambir. We conclude that the spaceborne remote sensing techniques have the potential to

  9. Woody plant phylogenetic diversity mediates bottom-up control of arthropod biomass in species-rich forests.

    PubMed

    Schuldt, Andreas; Baruffol, Martin; Bruelheide, Helge; Chen, Simon; Chi, Xiulian; Wall, Marcus; Assmann, Thorsten

    2014-09-01

    Global change is predicted to cause non-random species loss in plant communities, with consequences for ecosystem functioning. However, beyond the simple effects of plant species richness, little is known about how plant diversity and its loss influence higher trophic levels, which are crucial to the functioning of many species-rich ecosystems. We analyzed to what extent woody plant phylogenetic diversity and species richness contribute to explaining the biomass and abundance of herbivorous and predatory arthropods in a species-rich forest in subtropical China. The biomass and abundance of leaf-chewing herbivores, and the biomass dispersion of herbivores within plots, increased with woody plant phylogenetic diversity. Woody plant species richness had much weaker effects on arthropods, but interacted with plant phylogenetic diversity to negatively affect the ratio of predator to herbivore biomass. Overall, our results point to a strong bottom-up control of functionally important herbivores mediated particularly by plant phylogenetic diversity, but do not support the general expectation that top-down predator effects increase with plant diversity. The observed effects appear to be driven primarily by increasing resource diversity rather than diversity-dependent primary productivity, as the latter did not affect arthropods. The strong effects of plant phylogenetic diversity and the overall weaker effects of plant species richness show that the diversity-dependence of ecosystem processes and interactions across trophic levels can depend fundamentally on non-random species associations. This has important implications for the regulation of ecosystem functions via trophic interaction pathways and for the way species loss may impact these pathways in species-rich forests.

  10. Soil resources and climate jointly drive variations in microbial biomass carbon and nitrogen in China's forest ecosystems

    NASA Astrophysics Data System (ADS)

    Zhou, Z. H.; Wang, C. K.

    2015-07-01

    Microbial metabolism plays a key role in regulating the biogeochemical cycle of forest ecosystems, but the mechanisms driving microbial growth are not well understood. Here, we synthesized 689 measurements on soil microbial biomass carbon (Cmic) and nitrogen (Nmic) and related parameters from 207 independent studies published during the past 15 years across China's forest ecosystems. Our objectives were to (1) examine patterns in Cmic, Nmic, and microbial quotient (i.e., Cmic / Csoil and Nmic / Nsoil rates) by climate zones and management regimes for these forests; and (2) identify the factors driving the variability in the Cmic, Nmic, and microbial quotient. There was a large variability in Cmic (390.2 mg kg-1), Nmic (60.1 mg kg-1), Cmic : Nmic ratio (8.25), Cmic / Csoil rate (1.92 %), and Nmic/ Nsoil rate (3.43 %) across China's forests, with coefficients of variation varying from 61.2 to 95.6 %. The natural forests had significantly greater Cmic and Nmic than the planted forests, but had less Cmic : Nmic ratio and Cmic / Csoil rate. Soil resources and climate together explained 24.4-40.7 % of these variations. The Cmic : Nmic ratio declined slightly with the Csoil : Nsoil ratio, and changed with latitude, mean annual temperature and precipitation, suggesting a plastic homeostasis of microbial carbon-nitrogen stoichiometry. The Cmic/ Csoil and Nmic / Nsoil rates were responsive to soil resources and climate differently, suggesting that soil microbial assimilation of carbon and nitrogen be regulated by different mechanisms. We conclude that soil resources and climate jointly drive microbial growth and metabolism, and also emphasize the necessity of appropriate procedures for data compilation and standardization in cross-study syntheses.

  11. Reviews and syntheses: Soil resources and climate jointly drive variations in microbial biomass carbon and nitrogen in China's forest ecosystems

    NASA Astrophysics Data System (ADS)

    Zhou, Z. H.; Wang, C. K.

    2015-11-01

    Microbial metabolism plays a key role in regulating the biogeochemical cycle of forest ecosystems, but the mechanisms driving microbial growth are not well understood. Here, we synthesized 689 measurements on soil microbial biomass carbon (Cmic) and nitrogen (Nmic) and related parameters from 207 independent studies published up to November 2014 across China's forest ecosystems. Our objectives were to (1) examine patterns in Cmic, Nmic, and microbial quotient (i.e., Cmic / Csoil and Nmic / Nsoil rates) by climate zones and management regimes for these forests; and (2) identify the factors driving the variability in the Cmic, Nmic, and microbial quotient. There was a large variability in Cmic (390.2 mg kg-1), Nmic (60.1 mg kg-1, Cmic : Nmic ratio (8.25), Cmic / Csoil rate (1.92 %), and Nmic / Nsoil rate (3.43 %) across China's forests. The natural forests had significantly greater Cmic (514.1 mg kg-1 vs. 281.8 mg kg-1) and Nmic (82.6 mg kg-1 vs. 39.0 mg kg-1) than the planted forests, but had less Cmic : Nmic ratio (7.3 vs. 9.2) and Cmic / Csoil rate (1.7 % vs. 2.1 %). Soil resources and climate together explained 24.4-40.7 % of these variations. The Cmic : Nmic ratio declined slightly with Csoil : Nsoil ratio, and changed with latitude, mean annual temperature and precipitation, suggesting a plasticity of microbial carbon-nitrogen stoichiometry. The Cmic / Csoil rate decreased with Csoil : Nsoil ratio, whereas the Nmic / Nsoil rate increased with Csoil : Nsoil ratio; the former was influenced more by soil resources than by climate, whereas the latter was influenced more by climate. These results suggest that soil microbial assimilation of carbon and nitrogen are jointly driven by soil resources and climate, but may be regulated by different mechanisms.

  12. Implementation of a Biomass Energy Island for a Forested Air Force Installation.

    DTIC Science & Technology

    1983-01-01

    pine (CSP) plantations on Eglin AFB to establish Eglin as a Biomass Energy Island (BEI). Previous studies have demonstrated: (1) the feasibility of...AFB as a Biomass Energy Island (BEI). As such, Eglin would satisfy all energy needs of the facility by using 540,000 green tons of wood chips harvested

  13. 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.

  14. 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.

  15. Mortality as a key driver of the spatial distribution of aboveground biomass in Amazonian forests: results from a Dynamic Vegetation Model

    NASA Astrophysics Data System (ADS)

    Delbart, N.; Ciais, P.; Chave, J.; Viovy, N.; Malhi, Y.; Le Toan, T.

    2010-04-01

    Dynamic Vegetation Models (DVMs) simulate energy, water and carbon fluxes between the ecosystem and the atmosphere, between the vegetation and the soil, and between plant organs. They also estimate the potential biomass of a forest in equilibrium having grown under a given climate and atmospheric CO2 level. In this study, we evaluate the above ground woody biomass (AGWB) and the above ground woody Net Primary Productivity (NPPAGW) simulated by the DVM ORCHIDEE across Amazonian forests, by comparing the simulation results to a large set of ground measurements (220 sites for biomass, 104 sites for NPPAGW). We found that the NPPAGW is on average overestimated by 63%. We also found that the fraction of biomass that is lost through mortality is 85% too high. These model biases nearly compensate each other to give an average simulated AGWB close to the ground measurement average. Nevertheless, the simulated AGWB spatial distribution differs significantly from the observations. Then, we analyse the discrepancies in biomass with regards to discrepancies in NPPAGW and those in the rate of mortality. When we correct for the error in NPPAGW, the errors on the spatial variations in AGWB are exacerbated, showing clearly that a large part of the misrepresentation of biomass comes from a wrong modelling of mortality processes. Previous studies showed that Amazonian forests with high productivity have a higher mortality rate than forests with lower productivity. We introduce this relationship, which results in strongly improved modelling of biomass and of its spatial variations. We discuss the possibility of modifying the mortality modelling in ORCHIDEE, and the opportunity to improve forest productivity modelling through the integration of biomass measurements, in particular from remote sensing.

  16. Mortality as a key driver of the spatial distribution of aboveground biomass in Amazonian forest: results from a dynamic vegetation model

    NASA Astrophysics Data System (ADS)

    Delbart, N.; Ciais, P.; Chave, J.; Viovy, N.; Malhi, Y.; Le Toan, T.

    2010-10-01

    Dynamic Vegetation Models (DVMs) simulate energy, water and carbon fluxes between the ecosystem and the atmosphere, between the vegetation and the soil, and between plant organs. They also estimate the potential biomass of a forest in equilibrium having grown under a given climate and atmospheric CO2 level. In this study, we evaluate the Above Ground Woody Biomass (AGWB) and the above ground woody Net Primary Productivity (NPPAGW) simulated by the DVM ORCHIDEE across Amazonian forests, by comparing the simulation results to a large set of ground measurements (220 sites for biomass, 104 sites for NPPAGW). We found that the NPPAGW is on average overestimated by 63%. We also found that the fraction of biomass that is lost through mortality is 85% too high. These model biases nearly compensate each other to give an average simulated AGWB close to the ground measurement average. Nevertheless, the simulated AGWB spatial distribution differs significantly from the observations. Then, we analyse the discrepancies in biomass with regards to discrepancies in NPPAGW and those in the rate of mortality. When we correct for the error in NPPAGW, the errors on the spatial variations in AGWB are exacerbated, showing clearly that a large part of the misrepresentation of biomass comes from a wrong modelling of mortality processes. Previous studies showed that Amazonian forests with high productivity have a higher mortality rate than forests with lower productivity. We introduce this relationship, which results in strongly improved modelling of biomass and of its spatial variations. We discuss the possibility of modifying the mortality modelling in ORCHIDEE, and the opportunity to improve forest productivity modelling through the integration of biomass measurements, in particular from remote sensing.

  17. Effect of redox conditions on bacterial and fungal biomass and carbon dioxide production in Louisiana coastal swamp forest sediment.

    PubMed

    Seo, Dong Cheol; DeLaune, Ronald D

    2010-08-01

    Fungal and bacterial carbon dioxide (CO2) production/emission was determined under a range of redox conditions in sediment from a Louisiana swamp forest used for wastewater treatment. Sediment was incubated in microcosms at 6 Eh levels (-200, -100, 0, +100, +250 and +400 mV) covering the anaerobic range found in wetland soil and sediment. Carbon dioxide production was determined by the substrate-induced respiration (SIR) inhibition method. Cycloheximide (C15H23NO4) was used as the fungal inhibitor and streptomycin (C21H39N7O12) as the bacterial inhibitor. Under moderately reducing conditions (Eh > +250 mV), fungi contributed more than bacteria to the CO2 production. Under highly reducing conditions (Eh < or = 0 mV), bacteria contributed more than fungi to the total CO2 production. The fungi/bacteria (F/B) ratios varied between 0.71-1.16 for microbial biomass C, and 0.54-0.94 for microbial biomass N. Under moderately reducing conditions (Eh > or = +100 mV), the F/B ratios for microbial biomass C and N were higher than that for highly reducing conditions (Eh < or = 0 mV). In moderately reducing conditions (Eh > or = +100 mV), the C/N microbial biomass ratio for fungi (C/N: 13.54-14.26) was slightly higher than for bacteria (C/N: 9.61-12.07). Under highly reducing redox conditions (Eh < or = 0 mV), the C/N microbial biomass ratio for fungi (C/N: 10.79-12.41) was higher than for bacteria (C/N: 8.21-9.14). For bacteria and fungi, the C/N microbial biomass ratios under moderately reducing conditions were higher than that in highly reducing conditions. Fungal CO2 production from swamp forest could be of greater ecological significance under moderately reducing sediment conditions contributing to the greenhouse effect (GHE) and the global warming potential (GWP). However, increases in coastal submergence associated with global sea level rise and resultant decrease in sediment redox potential from increased flooding would likely shift CO2 production to bacteria rather than

  18. [Effects of forest gap on seasonal dynamics of soil organic carbon and microbial biomass car- bon in Picea asperata forest in Miyaluo of Western Sichuan, Southwest China].

    PubMed

    Zhou, Yi-Gui; Hao, Kai-Jie; Li, Xian-Wei; Fan, Chuan; Chen, Yue-Lin; Liu, Yun-Ke; Wang, Xie

    2014-09-01

    Effects of gap sizes (50, 100 and 150 m2) on seasonal dynamics of soil organic carbon (SOC) and microbial biomass carbon (MBC) in soil surface (0-15 cm) and subsurface (15-30 cm) were investigated in a 50-year old Picea asperata plantation in Miyaluo forest, Western Si- chuan, China. In the four seasons, the SOC and MBC contents were higher in the soil surface than in soil subsurface in the four treatments, and varied insignificantly in different seasons. Compared with the control, the SOC content increased by 35.4%, 21.2% and 10.3% in soil surface, and by 45.5%, 25.0% and 12.1% in soil subsurface with the forest gaps of 50, 100 and 150 m2, respectively. The MBC content increased by 26.7%, 16.7%, 11.3% and 24.4%, 12.6%, 7.3% in soil surface and subsurface, respectively. There were significant negative relationship between soil SOC content and the soil pH and moisture, and significant positive relationship between soil SOC content and soil temperature. Significant effects of SOC content, soil pH, soil temperature, soil moisture on MBC content were observed, suggesting that forest gaps could significantly affect envi- ronmental conditions, and increasing gaps could reduce microbial activity and decomposition rate and decrease soil SOC and MBC contents.

  19. Modelling and prediction of air pollutant transport during the 2014 biomass burning and forest fires in peninsular Southeast Asia.

    PubMed

    Duc, Hiep Nguyen; Bang, Ho Quoc; Quang, Ngo Xuan

    2016-02-01

    During the dry season, from November to April, agricultural biomass burning and forest fires especially from March to late April in mainland Southeast Asian countries of Myanmar, Thailand, Laos and Vietnam frequently cause severe particulate pollution not only in the local areas but also across the whole region and beyond due to the prevailing meteorological conditions. Recently, the BASE-ASIA (Biomass-burning Aerosols in South East Asia: Smoke Impact Assessment) and 7-SEAS (7-South-East Asian Studies) studies have provided detailed analysis and important understandings of the transport of pollutants, in particular, the aerosols and their characteristics across the region due to biomass burning in Southeast Asia (SEA). Following these studies, in this paper, we study the transport of particulate air pollution across the peninsular region of SEA and beyond during the March 2014 burning period using meteorological modelling approach and available ground-based and satellite measurements to ascertain the extent of the aerosol pollution and transport in the region of this particular event. The results show that the air pollutants from SEA biomass burning in March 2014 were transported at high altitude to southern China, Hong Kong, Taiwan and beyond as has been highlighted in the BASE-ASIA and 7-SEAS studies. There are strong evidences that the biomass burning in SEA especially in mid-March 2014 has not only caused widespread high particle pollution in Thailand (especially the northern region where most of the fires occurred) but also impacted on the air quality in Hong Kong as measured at the ground-based stations and in LulinC (Taiwan) where a remote background monitoring station is located.

  20. Distribution of Aboveground Live Biomass in the Amazon Basin

    NASA Technical Reports Server (NTRS)

    Saatchi, S. S.; Houghton, R. A.; DosSantos Alvala, R. C.; Soares, J. V.; Yu, Y.

    2007-01-01

    The amount and spatial distribution of forest biomass in the Amazon basin is a major source of uncertainty in estimating the flux of carbon released from land-cover and land-use change. Direct measurements of aboveground live biomass (AGLB) are limited to small areas of forest inventory plots and site-specific allometric equations that cannot be readily generalized for the entire basin. Furthermore, there is no spaceborne remote sensing instrument that can measure tropical forest biomass directly. To determine the spatial distribution of forest biomass of the Amazon basin, we report a method based on remote sensing metrics representing various forest structural parameters and environmental variables, and more than 500 plot measurements of forest biomass distributed over the basin. A decision tree approach was used to develop the spatial distribution of AGLB for seven distinct biomass classes of lowland old-growth forests with more than 80% accuracy. AGLB for other vegetation types, such as the woody and herbaceous savanna and secondary forests, was directly estimated with a regression based on satellite data. Results show that AGLB is highest in Central Amazonia and in regions to the east and north, including the Guyanas. Biomass is generally above 300Mgha(sup 1) here except in areas of intense logging or open floodplains. In Western Amazonia, from the lowlands of Peru, Ecuador, and Colombia to the Andean mountains, biomass ranges from 150 to 300Mgha(sup 1). Most transitional and seasonal forests at the southern and northwestern edges of the basin have biomass ranging from 100 to 200Mgha(sup 1). The AGLB distribution has a significant correlation with the length of the dry season. We estimate that the total carbon in forest biomass of the Amazon basin, including the dead and below ground biomass, is 86 PgC with +/- 20% uncertainty.

  1. Biomass in conifer plantations of northeastern Minnesota. Forest Service research paper

    SciTech Connect

    Ohmann, L.F.

    1985-10-01

    The report provides biomass estimates for vegetative strata and herb-low shrub species for 53 conifer plantations in NE Minnesota. The estimates are analyzed by plantation age and silvicultural practices used to establish and release the plantations.

  2. The microbial biomass and its activity and structure in the soils of old forests in the European Russia

    NASA Astrophysics Data System (ADS)

    Stolnikova, E. V.; Ananyeva, N. D.; Chernova, O. V.

    2011-04-01

    The humus-accumulative layer of soils (podzolic, gray, rzhavozem, burozem, and karbolitozem) of old-age forests (>60-450 years old) localized in various vegetation subzones (middle-taiga, southern taiga, subtaiga, dark coniferous forests outside the boreal region, and mountain forests) of the European part of Russia (22 sites of soil sampling of them, 13 in nature reserves and specially protected territories) was studied. The carbon content of the microbial biomass (Cmic) in the soil was determined by the substrate-induced respiration method. The fungal to bacterial ratio was determined by the selective inhibition technique with antibiotics. The basal respiration ( BR) was also measured. The BR/Cmic = qCO2 ratio and the portion of Cmic in the total organic soil carbon was determined. It was shown that the Cmic and BR in the soils of a separate vegetation subzone varied significantly; however, their values increased from the middle-taiga to dark coniferous subzone and decreased in the mountain-forest zone (348 ± 44, 670 ± 66, 1000 ± 86, 1142 ± 49, 789 ± 79 μkg C/g soil and from 0.68 ± 0.23, 1.85 ± 0.10, 2.13 ± 0.15, 1.56 ± 0.14, 0.92 ± 0.07 μkg CO2-C/soil h, respectively). The fungal component in the humus-accumulative layer of soils is 53-99% of the total Cmic; however, its absolute values increase from the middle subzone to the southern one. The Cmic pool and the total BR in the profile of some soils (mineral horizons and forest litter) were calculated.

  3. The relationship between tree biodiversity and biomass dynamics changes with tropical forest succession.

    PubMed

    Lasky, Jesse R; Uriarte, María; Boukili, Vanessa K; Erickson, David L; John Kress, W; Chazdon, Robin L

    2014-09-01

    Theory predicts shifts in the magnitude and direction of biodiversity effects on ecosystem function (BEF) over succession, but this theory remains largely untested. We studied the relationship between aboveground tree biomass dynamics (Δbiomass) and multiple dimensions of biodiversity over 8-16 years in eight successional rainforests. We tested whether successional changes in diversity-Δbiomass correlations reflect predictions of niche theories. Diversity-Δbiomass correlations were positive early but weak later in succession, suggesting saturation of niche space with increasing diversity. Early in succession, phylogenetic diversity and functional diversity in two leaf traits exhibited the strongest positive correlations with Δbiomass, indicating complementarity or positive selection effects. In mid-successional stands, high biodiversity was associated with greater mortality-driven biomass loss, i.e. negative selection effects, suggesting successional niche trade-offs and loss of fast-growing pioneer species. Our results demonstrate that BEF relationships are dynamic across succession, thus successional context is essential to understanding BEF in a given system.

  4. [Effects of Slope Position and Soil Horizon on Soil Microbial Biomass and Abundance in Karst Primary Forest of Southwest China].

    PubMed

    Feng, Shu-zhen; Su, Yi-rong; Zhang, Wei; Chen, Xiang-bi; He, Xun-yang

    2015-10-01

    To explore the effects of slope position and soil horizon on soil microbial biomass and abundance, chloroform fumigation extraction methods and real-time fluorescence-based quantitative PCR (Real-time PCR) were adopted to quantify the changes of soil microbial biomass C, N and abundance of bacteria and fungi, respectively. Soil samples were harvested from three horizons along profile, i. e., leaching horizon (A, 0-10 cm), transitional horizon (AB, 30-50 cm) and alluvial horizon (B, 70-100 cm), which were collected from the upper, middle and lower slope positions of a karst primary forest ecosystem. The results showed that slope position, soil horizon and their interaction significantly influenced the soil microbial biomass and abundance (P < 0.05). Different from A horizon, where SMBC was greater in lower than in upper slope position (P < 0.05), SMBC in AB and B horizons were highest in middle slope position. Similarly, SMBN was greater in lower than in upper slope position for A, AB and B horizons. Besides soil bacterial abundance in B horizon and fungal abundance in AB layer, the middle slope position had the highest value for all the three soil horizons (P < 0.05). Stepwise regression analysis showed that soil organic carbon, available nitrogen and pH were the key factors responsible for SMBC and SMBN variation, respectively, while the important factors responsible for the variation of bacteria abundance were available nitrogen and available phosphorus, and that for fungi abundance variation were available potassium.

  5. Empirical Constraints on Water Stress-induced Tree Mortality and its Impacts on Forest Biomass Dynamics in Western North America

    NASA Astrophysics Data System (ADS)

    Hember, R. A.; Kurz, W.; Coops, N. C.

    2015-12-01

    It is widely appreciated that forest biomass dynamics do not follow smooth sigmoidal age response functions, yet accounting for realistic overshoot-and-collapse cycles remains a big challenge. Here, millions of observations of vital status at permanent sample plots from Canada and the U.S. were used to predict probability of tree mortality (Pm) based on segmented logistic regression functions of xylem water potential (WPX) derived from a simplified model of plant water transport for dominant boreal and temperate North American tree species. First, we demonstrate that hydraulic limits are clearly detectable from the increase of Pm at the lowest levels of WPX and that the relationship is strongly defined by increasing vulnerability (decreasing WPX) as tree height (h) increases. Second, we demonstrate the implications of representing water stress-induced mortality on regional simulations of net ecosystem biomass production (NEBP), drawing on examples of specific collapse events where we have observations of NEBP for comparison. Simulations suggest that extreme surface energy balance anomalies during 1981 and 1998 triggered catastrophic levels of mortality in regions of western North America. Yet, simulations may still greatly underestimate the impact of these collapse events if associations exist between WPX and insect outbreaks. Nevertheless, the models suggest that a combination of size-dependent hydraulic limits and low-frequency variability in the surface energy balance conspire to produce overshoot-and-collapse cycles that strongly shaped biomass dynamics in western North America over recent decades.

  6. The effect of increased air humidity on fine root and rhizome biomass and turnover of silver birch forest ecosystem - a FAHM study.

    NASA Astrophysics Data System (ADS)

    Ostonen, I.; Kupper, P.; Sõber, J.; Aosaar, J.; Varik, M.; Lõhmus, K.

    2012-04-01

    A facility for free air humidity manipulation (FAHM) was established to investigate the effect of increased air humidity on belowground biomass and turnover in silver birch (Betula pendula Roth.) forest ecosystems with respect to rising air humidity predicted for Northern Europe. Fine root and rhizomes are short-lived and recognized as the most important component contributing to below-ground C fluxes in forests. The FAHM system enables air relative humidity to be increased on average 7 units (%) over the ambient level during mist fumigation. The experimental site contains humidified (H) and control (C) plots; each plot contains sectors with diverse "forest" understory and early successional grasses. The trees were planted in 2006, humidification started in spring 2008, and soil cores to study fine root and rhizome biomass and turnover were taken in 2007, 2009 and 2010. In July 2009, total fine root and rhizome biomass was 8 tons per ha in C and 16 tons per ha in H plots. The roots of understory formed 86% in C and 93% H plots, respectively. Our preliminary data suggest that the increased humidity affected more the roots of understory plants: fine root and rhizome biomass and production increased approximately twice by increasing air humidity. However, the tendency was similar for fine root biomass and production of silver birch. Fine root turnover speeded up for both silver birch and understory roots in H plots. Hence, changes in air humidity can significantly affect forest carbon cycling.

  7. Modeling forest carbon cycle response to tree mortality: Effects of plant functional type and disturbance intensity

    NASA Astrophysics Data System (ADS)

    Frasson, Renato Prata de Moraes; Bohrer, Gil; Medvigy, David; Matheny, Ashley M.; Morin, Timothy H.; Vogel, Christoph S.; Gough, Christopher M.; Maurer, Kyle D.; Curtis, Peter S.

    2015-11-01

    Natural and anthropogenic disturbances influence ecological succession and impact the carbon cycle. Understanding disturbance effects and ecosystem recovery is essential to carbon modeling. We hypothesized that (1) species-specific disturbances impact the carbon cycle differently from nonspecific disturbances. In particular, disturbances that target early-successional species will lead to higher carbon uptake by the postrecovery, middle- and late-successional community and (2) disturbances that affect the midsuccessional deciduous species have more intense and long-lasting impacts on carbon uptake than disturbances of similar intensity that only affect the early-successional species. To test these hypotheses, we employed a series of simulations conducted with the Ecosystem Demography model version 2 to evaluate the sensitivity of a temperate mixed-deciduous