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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,045 records · Page 58
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Satellite Earth observation data to identify climate and anthropogenic pressures on Bucharest periurban forests

Satellite Earth observation data in the visible and near-infrared (VNIR) wavelengths represent a useful source of information for forest systems monitoring through derived biogeophysical parameters (vegetation index, leaf area index, canopy cover, fraction of absorbed photosynthetically active radiation, chlorophyll content, net primary production, canopy water stress, etc.). Use of satellite remote sensing data to assess forest spatio-temporal changes due to climatic or anthropogenic stressors is an excellent example of the value of multispectral and multitemporal observations. Fusion technique was applied to time-series multispectral and multitemporal satellite imagery (NOAA AVHRR, MODIS Terra/Aqua, Landsat ETM and IKONOS satellite data) for periurban forest areas Cernica-Branesti, placed in the neighboring of Bucharest town, Romania, over 2002-2014 period.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Modeling of the high column density systems in the Lyman-Alpha forest

The Lyman-α forests observed in the spectra of high-redshift quasars can be used as a tracer of the cosmological matter density to study baryon acoustic oscillations (BAO) and the Alcock-Paczynski effect. Extraction of cosmological information from these studies requires modeling of the forest correlations. While the models depend most importantly on the bias parameters of the intergalactic medium (IGM), they also depend on the numbers and characteristics of high-column-density systems (HCDs) ranging from Lyman-limit systems with column densities log N HI /1cm -2 > 17 to damped Lyman-α systems (DLAs) with log N HI /1cm -2 > 20.2. These HCDs introduce broad damped absorption characteristic of a Voigt profile. Consequently they imprint a component on the power spectrum whose modes in the radial direction are suppressed, leading to a scale-dependent bias. Using mock data sets of known HCD content, we test a model that describes this effect in terms of the distribution of column densities of HCDs, the Fourier transforms of their Voigt profiles and the bias of the halos containing the HCDs. Our results show that this physically well-motivated model describes the effects of HCDs with an accuracy comparable to that of the ad-hoc models used in published forest analyses. We also discuss the problems of applying the model to real data, where the HCD content and their bias is uncertain.

Lyman alpha forest↗
DOE OSTI2016

Unraveling the mechanisms underlying pulse dynamics of soil respiration in tropical dry forests

Tropical dry forests are already undergoing changes in the quantity and timing of rainfall, but there is great uncertainty over how these shifts will affect belowground carbon (C) cycling. While it has long been known that dry soils quickly release carbon dioxide (CO 2 ) upon rewetting, the mechanisms underlying the so-called 'Birch effect' are still debated. Here, we quantified soil respiration pulses and their biotic predictors in response to simulated precipitation events in a regenerating tropical dry forest in Costa Rica. We also simulated the observed rewetting CO 2 pulses with two soil carbon models: a conventional model assuming first-order decay rates of soil organic matter, and an enzyme-catalyzed model with Michaelis–Menten kinetics. We found that rewetting of dry soils produced an immediate and dramatic pulse of CO 2 , accompanied by rapid immobilization of nitrogen into the microbial biomass. However, the magnitude of the rewetting CO 2 pulse was highly variable at fine spatial scales, and was well correlated with the size of the dissolved organic C pool prior to rewetting. Both the enzyme-catalyzed and conventional models were able to reproduce the Birch effect when respiration was coupled directly to microbial C uptake, although models differed in their ability to yield realistic estimates of SOC and microbial biomass pool sizes and dynamics. Lastly, our results suggest that changes in the timing and intensity of rainfall events in tropical dry forests will exert strong influence on ecosystem C balance by affecting the dynamics of microbial biomass growth.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

From individual leaves to forest stands: importance of niche, distance decay, and stochasticity vary by ecosystem type and functional group for fungal community composition

Abstract Community assembly is influenced by environmental niche processes as well as stochastic processes that can be spatially dependent (e.g. dispersal limitation) or independent (e.g. priority effects). Here, we sampled senesced tree leaves as unit habitats to investigate fungal community assembly at two spatial scales: (i) small neighborhoods of overlapping leaves from differing tree species and (ii) forest stands of differing ecosystem types. Among forest stands, ecosystem type explained the most variation in community composition. Among adjacent leaves within stands, variability in fungal composition was surprisingly high. Leaf type was more important in stands with high soil fertility and dominated by differing tree mycorrhizal types (sugar maple vs. basswood or red oak), whereas distance decay was more important in oak-dominated forest stands with low soil fertility. Abundance of functional groups was explained by environmental factors, but predictors of taxonomic composition within differing functional groups were highly variable. These results suggest that fungal community assembly processes are clearest for functional group abundances and large spatial scales. Understanding fungal community assembly at smaller spatial scales will benefit from further study focusing on differences in drivers for different ecosystems and functional groups, as well as the importance of spatially independent factors such as priority effects.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2012

Partitioning in trees and soil (PiTS) - a experimental approach to improve knowledge of forest carbon dynamics

Summary The dynamics of rapid changes in carbon (C) partitioning within forest ecosystems are not well understood, which limits improvement of mechanistic models of C cycling. Our objective was to inform model processes by describing relationships between C partitioning and accessible environmental or physiological measurements, with a special emphasis on belowground C flux. We exposed eight 7-year-old loblolly pine trees to air enriched with 13CO2 and then implemented adjacent light shade (LS) and heavy shade (HS) treatments in order to manipulate C uptake and flux. A soil pit was dug adjacent to the trees to provide greater access belowground. The impacts of shading on photosynthesis, plant water potential, sap flow, basal area growth, root growth, and soil C exchange rate (CER) were assessed for each tree over a three-week period. The progression of the 13C label was concurrently tracked from the atmosphere through foliage, phloem, roots, and soil CO2 efflux. The HS treatment significantly reduced C uptake, sap flow, stem growth and root standing crop, and resulted in greater residual soil water content to 1 m depth. Sap flow was strongly correlated with CER on the previous day, but not the current day, with no apparent treatment effect on the relationship. The 13C label was immediately detected in foliage on label day (half-life = 0.5 d), progressed through phloem by day 2 (half-life = 4.7 d), roots by day 2-4, and subsequently was evident as respiratory release from soil which peaked between days 3-6. The 13C of soil CO2 efflux was strongly correlated with phloem 13C on the previous day, or two days earlier. These data detail the timing and relative magnitude of C flux through a young pine stand in relation to environmental conditions. Refinement of belowground sampling will be necessary to adequately separate and quantify the flux of recently fixed C into roots, and fate of that new C as respiratory, mycorrhizal or exudative release, storage or partitioning into new root biomass.

09 BIOMASS FUELS↗
DOE OSTI2022

Watershed-scale liming reveals the short- and long- term effects of pH on the forest soil microbiome and carbon cycling

Soil microbial community composition routinely correlates with pH, reflecting both direct pH effects on microbial physiology and long-term biogeochemical feedbacks. For this work, we used two watershed-scale liming experiments to identify short- (2 years) and long-term (25 years) changes in the structure and function of bacterial and fungal communities in organic horizons (O e and O a ) of acid forest soils. Liming increased soil pH, extractable calcium, and soil carbon stocks, reduced biomass-specific respiration, and caused major changes in the soil microbiome in the short and long term. More taxa responded to liming in the short term (70%) than in the long term (30%), with most showing consistent directional responses at both sites. The ratio of change in relative abundance between limed and reference sites was twofold higher at the long than the short-term site, indicating that the effects of liming grew over time. Liming impacts were most pronounced in fungi, as steep declines of dominant ectomycorrhizal fungi ( Cenococcum and Russula ) occurred at both sites. Liming favoured neutrophilic bacteria over acidophilic populations according to estimated environmental pH optima. Collectively, these results demonstrate that a liming-induced change of one pH unit has an immediate and persistent effect on the structure and function of microbial communities in acid forest soils. The corresponding suppression of respiration indicates that anthropogenic alterations of soil pH, as driven by acid deposition or liming, can affect forest floor C stocks due to pH-driven shifts in community structure.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

Phosphorus rather than nitrogen enhances CO 2 emissions in tropical forest soils: Evidence from a laboratory incubation study

Ecosystem functional responses such as soil CO 2 emissions are constrained by microclimate, available carbon (C) substrates and their effects upon microbial activity. In tropical forests, phosphorus (P) is often considered as a limiting factor for plant growth, but it is still not clear whether P constrains microbial CO 2 emissions from soils. In this study, we incubated seven tropical forest soils from Brazil and Puerto Rico with different nutrient addition treatments (no addition - Control, C, nitrogen (N) or P addition only; and combined C, N, and P addition (CNP)). Cumulative soil CO 2 emissions were fit with a Gompertz model to estimate potential maximum cumulative soil CO 2 emission ( C m ) and the rate of change of soil C decomposition ( k ). Quantitative polymerase chain reaction (qPCR) was conducted to quantify microbial biomass as bacteria and fungi. Results showed that P addition alone or in combination with C and N enhanced C m , whereas N addition usually reduced C m , and neither N nor P affected microbial biomass. Additions of CNP enhanced k , increased microbial abundances and altered fungal to bacterial ratios towards higher fungal abundance. Additions of CNP, however, tended to reduce C m for most soils when compared to C additions alone, suggesting that microbial growth associated with nutrient additions may have occurred at the expense of C decomposition. Altogether, this study demonstrates that soil CO 2 emission is more limited by P than N in tropical forest soils and those effects were stronger in soils low in P.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Limited effect of ozone reductions on the 20-year photosynthesis trend at Harvard forest

Ozone (O 3 ) damage to leaves can reduce plant photosynthesis, which suggests that declines in ambient O3 concentrations ([O 3 ]) in the United States may have helped increase gross primary production (GPP) in recent decades. Here, we assess the effect of long-term changes in ambient [O 3 ] using 20 years of observations at Harvard forest. Using artificial neural networks, we found that the effect of the inclusion of [O 3 ] as a predictor was slight, and independent of O 3 concentrations, which suggests limited high-frequency O 3 inhibition of GPP at this site. Simulations with a terrestrial biosphere model, however, suggest an average long-term O 3 inhibition of 10.4% for 1992–2011. A decline of [O 3 ] over the measurement period resulted in moderate predicted GPP trends of 0.02–0.04 μmol C m -2 s -1 yr -1 , which is negligible relative to the total observed GPP trend of 0.41 μmol C m -2 s -1 yr -1 . A similar conclusion is achieved with the widely used AOT40 metric. Combined, our results suggest that ozone reductions at Harvard forest are unlikely to have had a large impact on the photosynthesis trend over the past 20 years. Such limited effects are mainly related to the slow responses of photosynthesis to changes in [O 3 ]. Furthermore, we estimate that 40% of photosynthesis happens in the shade, where stomatal conductance and thus [O 3 ] deposition is lower than for sunlit leaves. This portion of GPP remains unaffected by [O 3 ], thus helping to buffer the changes of total photosynthesis due to varied [O 3 ]. In conclusion, our analyses suggest that current ozone reductions, although significant, cannot substantially alleviate the damages to forest ecosystems.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Disentangling the long-term effects of disturbance on soil biogeochemistry in a wet tropical forest ecosystem

Climate change is increasing the intensity of severe tropical storms and cyclones (also referred to as hurricanes or typhoons), with major implications for tropical forest structure and function. These changes in disturbance regime are likely to play an important role in regulating ecosystem carbon (C) and nutrient dynamics in tropical and subtropical forests. Canopy opening and debris deposition resulting from severe storms have complex and interacting effects on ecosystem biogeochemistry. Disentangling these complex effects will be critical to better understand the long-term implications of climate change on ecosystem C and nutrient dynamics. In this paper, we used a well-replicated, long-term (10 years) canopy and debris manipulation experiment in a wet tropical forest to determine the separate and combined effects of canopy opening and debris deposition on soil C and nutrients throughout the soil profile (1 m). Debris deposition alone resulted in higher soil C and N concentrations, both at the surface (0–10 cm) and at depth (50–80 cm). Concentrations of NaOH-organic P also increased significantly in the debris deposition only treatment (20–90 cm depth), as did NaOH-total P (20–50 cm depth). Canopy opening, both with and without debris deposition, significantly increased NaOH-inorganic P concentrations from 70 to 90 cm depth. Soil iron concentrations were a strong predictor of both C and P patterns throughout the soil profile. Our results demonstrate that both surface- and subsoils have the potential to significantly increase C and nutrient storage a decade after the sudden deposition of disturbance-related organic debris. Our results also show that these effects may be partially offset by rapid decomposition and decreases in litterfall associated with canopy opening. Finally, the significant effects of debris deposition on soil C and nutrient concentrations at depth (>50 cm), suggest that deep soils are more dynamic than previously believed, and can serve as sinks of C and nutrients derived from disturbance-induced pulses of organic matter inputs.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Using remote sensing to quantify the additional climate benefits of California forest carbon offset projects

Abstract Nature‐based climate solutions are a vital component of many climate mitigation strategies, including California's, which aims to achieve carbon neutrality by 2045. Most carbon offsets in California's cap‐and‐trade program come from improved forest management (IFM) projects. Since 2012, various landowners have set up IFM projects following the California Air Resources Board's IFM protocol. As many of these projects approach their 10th year, we now have the opportunity to assess their effectiveness, identify best practices, and suggest improvements toward future protocol revisions. In this study, we used remote sensing‐based datasets to evaluate the carbon trends and harvest histories of 37 IFM projects in California. Despite some current limitations and biases, these datasets can be used to quantify carbon accumulation and harvest rates in offset project lands relative to nearby similar “control” lands before and after the projects began. Five lines of evidence suggest that the carbon accumulated in offset projects to date has generally not been additional to what might have otherwise occurred: (1) most forests in northwestern California have been accumulating carbon since at least the mid‐1980s and continue to accumulate carbon, whether enrolled in offset projects or not; (2) harvest rates were high in large timber company project lands before IFM initiation, suggesting they are earning carbon credits for forests in recovery; (3) projects are often located on lands with higher densities of low‐timber‐value species; (4) carbon accumulation rates have not yet increased on lands that enroll as offset projects, relative to their pre‐enrollment levels; and (5) harvest rates have not decreased on most project lands since offset project initiation. These patterns suggest that the current protocol should be improved to robustly measure and reward additionality. In general, our framework of geospatial analyses offers an important and independent means to evaluate the effectiveness of the carbon offsets program, especially as these data products continue improving and as offsets receive attention as a climate mitigation strategy.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2012

Forest phenology and a warmer climate - Growing season extension in relation to climatic provenance

Predicting forest responses to warming climates relies on assumptions about niche and temperature sensitivity that remain largely untested. Observational studies have related current and historical temperatures to phenological shifts, but experimental evidence is sparse, particularly for autumn responses. A five-year field experiment exposed four deciduous forest species from contrasting climates (Liquidambar styraciflua, Quercus rubra, Populus grandidentata, and Betula alleghaniensis) to air temperatures 2 and 4 C above ambient controls. Impacts of year-round warming on bud burst (BB), senescence and abscission were evaluated in relation to thermal provenance. Leaves emerged earlier in all species, by an average of 6-9 days at +2 and +4 C. Magnitude of advance varied with species and year, but was larger for the first 2 C increment than the second. The effect of warming increased with early BB, favoring Liquidambar, from the warmest climate, but even BB in northern species advanced, despite temperatures well beyond those of the realized niche. Treatment differences in BB were poorly explained by temperature sums, which increased with treatment. In autumn, chlorophyll was retained an average of 4 and 7 days longer in +2 and +4 C treatments, and abscission delayed by 8 and 13 days. Species differences in autumn responses were marginally significant. Growing seasons in the warmer atmospheres were 6 - 28 days longer, with the least impact in Quercus. Results are compared with a 16-year record of canopy onset and offset in a nearby upland deciduous forest, where BB showed similar responsiveness to spring temperatures (2 - 4 days C-1). Offset dates in the stand tracked August-September temperatures, except when late summer drought caused premature senescence. The common garden-like experimental approach provides evidence that warming alone extends the growing season, at both ends, even if stand-level impacts are complicated by other environmental factors.

aspen↗
DOE OSTI2023

Metatranscriptomics sheds light on the links between the functional traits of fungal guilds and ecological processes in forest soil ecosystems

Soil fungi belonging to different functional guilds, such as saprotrophs, pathogens, and mycorrhizal symbionts, play key roles in forest ecosystems. To date, no study has compared the actual gene expression of these guilds in different forest soils. We used metatranscriptomics to study the competition for organic resources by these fungal groups in boreal, temperate, and Mediterranean forest soils. Using a dedicated mRNA annotation pipeline combined with the JGI MycoCosm database, we compared the transcripts of these three fungal guilds, targeting enzymes involved in C- and N mobilization from plant and microbial cell walls. Genes encoding enzymes involved in the degradation of plant cell walls were expressed at a higher level in saprotrophic fungi than in ectomycorrhizal and pathogenic fungi. However, ectomycorrhizal and saprotrophic fungi showed similarly high expression levels of genes encoding enzymes involved in fungal cell wall degradation. Transcripts for N-related transporters were more highly expressed in ectomycorrhizal fungi than in other groups. Here, we showed that ectomycorrhizal and saprotrophic fungi compete for N in soil organic matter, suggesting that their interactions could decelerate C cycling. Metatranscriptomics provides a unique tool to test controversial ecological hypotheses and to better understand the underlying ecological processes involved in soil functioning and carbon stabilization.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Pervasive shifts in forest dynamics in a changing world

Forest dynamics arise from the interplay of environmental drivers and disturbances with the demographic processes of recruitment, growth, and mortality, subsequently driving biomass and species composition. However, forest disturbances and subsequent recovery are shifting with global changes in climate and land use, altering these dynamics. Changes in environmental drivers, land use, and disturbance regimes are forcing forests toward younger, shorter stands. Rising carbon dioxide, acclimation, adaptation, and migration can influence these impacts. Recent developments in Earth system models support increasingly realistic simulations of vegetation dynamics. In parallel, emerging remote sensing datasets promise qualitatively new and more abundant data on the underlying processes and consequences for vegetation structure. In combination, these advances hold promise for improving the scientific understanding of changes in vegetation demographics and disturbances.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Effects of Vegetation and Topography on the Boundary Layer Structure above the Amazon Forest

Observational data from two field campaigns in the Amazon forest were used to study the vertical structure of turbulence above the forest. The analysis was performed using the reduced turbulent kinetic energy (TKE) budget and its associated two-dimensional phase space. Results revealed the existence of two regions within the roughness sublayer in which the TKE budget cannot be explained by the canonical flat-terrain TKE budgets in the canopy roughness sublayer or in the lower portion of the convective ABL. Data analysis also suggested that deviations from horizontal homogeneity have a large contribution to the TKE budget. Results from LES of a model canopy over idealized topography presented similar features, leading to the conclusion that flow distortions caused by topography are responsible for the observed features in the TKE budget. These results support the conclusion that the boundary layer above the Amazon forest is strongly impacted by the gentle topography underneath.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

16S and ITS Amplicon Sequencing Fastq files and metadata from PARCHED Panama Tropical Forest soils, 2019-2020,

Model projections predict tropical forests will experience longer periods of drought and more intense precipitation cycles under a changing climate. Such transitions have implications for structure-function relationships within microbial communities. We examine how chronic drying might reshape prokaryotic and fungal communities across four lowland forests in Panama with a wide variation in mean annual precipitation and soil fertility. Four sites were established across a 1000 mm span in mean annual precipitation (2335 to 3300 mm). We expected microbial communities at sites with lower MAP to be less sensitive to chronic drying than sites with higher MAP; while fungal communities to be more resistant to disturbance than prokaryotes. At each location, partial throughfall exclusion structures were established over 10 x 10 m plots to reduce direct precipitation input. Raw demultiplexed sequences (bacteria, archaea, fungal) from soil samples taken from PARCHED Panama Tropical Forest throughfall exclusion experiments. Files that contain 16S are sequences from prokaryotes, ITS indicates sequences from fungi. Compressed fastq files are contained in Field_PARCHED_ITS_fastq_2020.zip, Field_PARCHED_ITS_fastq_2019.zip, Field_PARCHED_16S_fastq_2020.zip, Field_PARCHED_16S_fastq_2019.zip.There are four sites across the isthmus of Panama, each with 4 control and 4 exclusion plots. Throughfall exclusion shelters were built to intercept 50% of throughfall precipitation that hits the soil. Samples were taken on May 2019 and Jan 2020 from 0-10 cm and 10-20 cm depth approximately 9 and 18 months after shelter installation. Metadata and sample IDs for fastq files for 2019 sampling are within Field_PARCHED_Metadata_2019_ITS.csv and Field_PARCHED_Metadata_2019_16S.csv. The metadata for both 16S and ITS fastq files for January 2020 is included in Field_PARCHED_Metadata_2020.csv. No data processing or QA/QC was done on the raw data. Data processing example provided in R notebook file.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

GNSS-based Vegetation Optical Depth, Tree Sway, and Evapotranspiration data from the Niwot Ridge Subalpine Forest (US-NR1) AmeriFlux site

This data package contains data and information about Global Navigation Satellite System (GNSS)-based Vegetation Optical Depth (VOD), tree sway motion, and eddy-covariance evapotranspiration (ET) data collected at the Niwot Ridge Subalpine Forest AmeriFlux site (US-NR1). The raw GNSS data were collected between May 2022 and August 2023. Other processed datasets such as tree sway motion and ET data are also included. The goal was to study the water content within a subalpine forest and, more specifically, examine the canopy evaporation process. This data archive includes all data that were used within the following Biogeosciences discussion paper that further summarizes the research objectives and conclusions:Burns, S.P., V. Humphrey, E.D. Gutmann, M.S. Raleigh, D.R. Bowling, and P.D. Blanken, 2025: Using GNSS-based vegetation optical depth, tree sway motion, and eddy-covariance to examine evaporation of canopy-intercepted rainfall in a subalpine forest. EGUsphere [preprint],https://doi.org/10.5194/egusphere-2025-1755This data archive also supplements the 30-min Lawrence Berkeley National Laboratory (LBNL) AmeriFlux dataset for US-NR1 (i.e., https://doi.org/10.17190/AMF/1246088) and updates what was in the 2020 ESS-DIVE US-NR1 archive (https://doi.org/10.15485/1671825) to include data from the years 2020-2025. More specifically, the following updates are provided: (i) five-minute statistics (means, variances, covariances) of all data measured by the US-NR1 data system between Sep 2020 and Jun 2025 in netCDF format, (ii) the electronic logbook of US-NR1 site visits, (iii) a web calendar (in HTML format) documenting activity at the site (a replica of https://urquell.colorado.edu/calendar/), (iv) photos taken at the site between years 2020 and present day (Aug 2025), and (v) several auxiliary datasets, primary related to trees near the site, soil properties, soil moisture and soil temperature, and subcanopy radiation data. The data package is setup so that the web calendar, photos, and electronic logbook can be easily accessed on a local computer using a web browser. The provided data files are in either BINEX or SBF format (for the raw GNSS data), netCDF, CSV, ASCII, or MATLAB format. To obtain a better understanding about the archive, please start by reading the following PDF which is included within the data archive:README_ESS_DIVE_USNR1_2025_readme_first.pdf.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2026

AmeriFlux FLUXNET-1F CA-SF3 Saskatchewan - Western Boreal, forest burned in 1998

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site CA-SF3 Saskatchewan - Western Boreal, forest burned in 1998. This is the FLUXNET version of the carbon flux data for the site CA-SF3 Saskatchewan - Western Boreal, forest burned in 1998 produced by applying the standard ONEFlux (1F) software. Site Description - The 1998 burn site (F98) was in the east part of Prince Albert National Park, Saskatchewan, in the Waskesiu Fire, ignited by lightning that burned about 1700 ha in July 1998. The pre-fire forest consisted of jack pine and black spruce stands, with some intermixed aspen. The fire was severe, consuming much of the top layer of organic soil and killing all trees. In 2001, much of the regenerating vegetation consisted of aspen saplings about 1 m tall and shorter jack pine and black spruce seedlings. An overstory of dead, leafless jack pine trees dominated at a height of 18 m. Sparse grass and herbs, such as fireweed (Epilobium angustifolium L.) covered the ground. There were a large number of fallen dead trees, mostly perched above the ground and not decomposing quickly.

Amiro, Brian [University of Manitoba; Canadian For↗
DOE OSTI2026

AmeriFlux FLUXNET-1F US-Dk1 Duke Forest-open field

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-Dk1 Duke Forest-open field. This is the FLUXNET version of the carbon flux data for the site US-Dk1 Duke Forest-open field produced by applying the standard ONEFlux (1F) software. Site Description - The Duke Forest grass field is approximately 480×305 m, dominated by the C3 grass Festuca arundinacea Shreb. (tall fescue) includes minor components of C3 herbs and the C4 grass Schizachyrium scoparium (Michx.) Nash, not considered here. The site was burned in 1979 and is mowed annually during the summer for hay according to local practices. Lai, C.T. and G.G. Katul, 2000, "The dynamic role of root-water uptake in coupling potential to actual transpiration" , Advances in Water Resources, 23, 427-439; Novick , K.A., P. C. Stoy, G. G. Katul, D. S. Ellsworth, M. B. S. Siqueira, J. Juang, R. Oren, 2004, Carbon dioxide and water vapor exchange in a warm temperate grassland, Oecologia, 138, 259-274; Stoy PC, Katul GG, Siqueira MBS, Juang J-Y, McCarthy HR, Oishi AC, Uebelherr JM, Kim H-S, Oren R (2006). Separating the effects of climate and vegetation on evapotranspiration along a successional chronosequence in the southeastern U.S. Global Change Biology 12:2115-2135

Oishi, Chris [USDA Forest Service]↗