US Forest Research Articles

Modeling Regional Economic Contributions of Forest Restoration: A Case Study of the Four Forest Restoration Initiative

AbstractForest restoration positively affects rural economies by facilitating employment and income generation with logging, wood utilization, and other restoration activities. To investigate economic effects and modeling of forest restoration, a regional contribution analysis of the Four Forest Restoration Initiative (4FRI) in Arizona was conducted. With over 12,000 acres mechanically thinned in 2017, 4FRI treatments led to the processing of 400,000 green tons of sawlogs and biomass. Restoration activities spurred more than 900 full-time equivalent jobs in the region, $50 million in regional labor income, and affected over 140 different industry sectors in the region. When compared to the US Forest Service Treatments for Restoration Economic Analysis Tool model estimates for 4FRI economic contributions, we found that using primary data from 4FRI contractors provided more conservative results. Primary considerations for modeling forest restoration contributions include contractor surveys, appropriate investigation of the regional context, methodological transparency in bridging restoration expenditures to input-output models, and consideration of how to enhance restoration contributions.

The Development of an Organizational Safety Culture in the United States Forest Service

Abstract For over 100 years, the US Forest Service (USFS) has developed initiatives to improve safety outcomes. Herein we discuss the engineered solutions used from 1910 through 1994, when the agency relied on physical science to address the hazards of wildland fire suppression. We then interpret safety initiatives of the subsequent 25 years, as the USFS incorporated social science perspectives both into its understanding of emergency fire incidents and its mitigation of vulnerabilities across all fields of work. Tracing the safety programs using a historical sociology approach, we identify, within the agency’s narrative, three recent developments in its organizational safety culture: cultural awareness, cultural management, and cultural reorganization. This article describes how the development of top-down safety initiatives are questioned and shaped by employees who actively influence the trajectory of a safety culture in the USFS.

H-2B Guest Workers and the Critical Role They Play in US Forests

AbstractA survey of businesses that provide a variety of forest management services indicated the importance of H-2B guest workers in performing important tasks which facilitate management and sustainability of forest resources in the United States. Those workers accomplish a wide variety of tasks with tree planting being most common. Although the positions filled by those workers are first made available to US workers at government-mandated wage rates, few apply. Businesses reported that it is becoming increasingly difficult for them to secure all of their guest visas to fulfill their contacts. Although former President Donald J. Trump’s proclamation on June 22, 2020, suspending entry of workers with H-2B visas, would have resulted in approximately one million acres not being reforested by respondents in 2020, a National Interest Exemption process provided a reprieve through the end of 2020. A long-term solution is needed to ensure that there are enough H-2B workers available to continue providing these important services.

Trust is Essential to the Implementation of Adaptive Management on Public Lands

Adaptive management of natural resources explicitly incorporates learning into a process of science-based decision making. First proposed in the late 1970s, over time, adaptive management has become an increasingly common approach to management of complex social-ecological systems characterized by high uncertainty and conflict. Rangelands used for livestock production are one such system. Management outcomes of any given livestock operation are a unique combination of the local ecology found in a particular place, the management goals and approach of the operator and regulators, and regulatory requirements. Scholars have hypothesized that adaptive management can reduce conflict by allowing experimentation and increased management flexibility when there are competing viewpoints. We used a change to adaptive management for grazing allotment administration implemented by the US Forest Service in Arizona and New Mexico to evaluate this research question. We interviewed ranchers and Forest Service employees in Arizona and New Mexico to understand how they define adaptive management, what changes they experienced due to the shift to adaptive management, and their perceptions of the impacts of adaptive management. A decade after its implementation, our data show that adaptive management alone does not reduce conflict but can help reduce conflict where trust between permittees and the US Forest Service is strong. Where trust is lacking, adaptive management may strengthen existing patterns of conflict. These findings have important management implications for the use of adaptive management in the administration of public lands and as a conflict management tool.

Nonparametric Identification of First-Price Auctions with Heterogenous Bidders

In the auction literature, it is well established that bidders' asymmetry plays an important role in determining auction revenues. In this paper, we propose a nonparametric methodology to analyze first-price auctions with two popularly adopted asymmetries: heterogeneous risk preferences and asymmetric value distributions. We find that the two competing models provide distinct implications for the bid distributions conditional on heterogeneity. By modeling bidders' asymmetry as unobserved heterogeneity, we show that the conditional bid distributions are identified nonparametrically. These results enable researchers to distinguish between the two competing models. The Monte Carlo experiments demonstrate the good performance of the proposed method. In an application using the US Forest Service timber auction data, we find that the data support the model with heterogeneity in risk preference.

A Qualitative Study on the US Forest Service’s Risk Management Assistance Efforts to Improve Wildfire Decision-Making

To support improved wildfire incident decision-making, in 2017 the US Forest Service (Forest Service) implemented risk-informed tools and processes, together known as Risk Management Assistance (RMA). The Forest Service is developing tools such as RMA to improve wildfire decision-making and implements these tools in complex organizational environments. We assessed the perceived value of RMA and factors that affected its use to inform the literature on decision support for fire management. We sought to answer two questions: (1) What was the perceived value of RMA for line officers who received it?; and (2) What factors affected how RMA was received and used during wildland fire events? We conducted a qualitative study involving semi-structured interviews with decision-makers to understand the contextualized and interrelated factors that affect wildfire decision-making and the uptake of a decision-support intervention such as RMA. We used a thematic coding process to analyze our data according to our questions. RMA increased line officers’ ability to communicate the rationale underlying their decisions more clearly and transparently to their colleagues and partners. Our interviewees generally said that RMA data analytics were valuable but did not lead to changes in their decisions. Line officer personality, pre-season exposure to RMA, local political dynamics and conditions, and decision biases affected the use of RMA. Our findings reveal the complexities of embracing risk management, not only in the context of US federal fire management, but also in other similar emergency management contexts. Attention will need to be paid to existing decision biases, integration of risk management approaches in the interagency context, and the importance of knowledge brokers to connect across internal organizational groups. Our findings contribute to the literature on managing change in public organizations, specifically in emergency decision-making contexts such as fire management.

Ensuring that Science Has a Seat at the Table

With crises including devastating weather and climate disasters, scientists have an important role to play in decision-making. Shown here is a tree ridge during the 2018 Woolsey Fire in California, which burned nearly 97,000 acres and killed 3 people. Photograph: Courtesy of Peter Buschmann, US Forest Service. With the world still gripped by the coronavirus, with devastating weather and climate disasters, and with attacks on science being spread through disinformation campaigns, there has never been a greater need for scientific engagement with public policy. Leaders in the scientific community are calling for better ways to incorporate science into decision-making during periods of crisis and beyond. Despite the challenges, these leaders are cautiously optimistic that science can have a meaningful seat at the table and that it can play an integral and balanced role in decision-making for government leaders and in informing the general public. Some of the optimism stems from the promises of the Biden administration to restore scientific integrity to federal policymaking. His early appointments on climate change, energy, and environmental policy have been encouraging.

Forest Thinning in Ponderosa Pines Increases Carbon Use Efficiency and Energy Flow From Primary Producers to Primary Consumers

AbstractA better understanding of carbon use efficiency (CUE) and carbon allocation during disturbance is critical to improve simulations of the global carbon cycle and understanding future climate impacts. Forest thinning of high‐stem density, high elevation dry western US forests is becoming more common to reduce severe fire danger but there are uncertainties about how forest thinning may impact forest CUE, carbon allocation and energy flow through the food chain. In three, quarter ha stands with similar soils, elevation and climate along a forest thinning gradient near Flagstaff (AZ), we measured total net primary production (NPP of wood, fine root, and leaves), total autotrophic respiration (Ra of wood, rhizosphere, and canopy respiration), gross primary production (GPP = NPP + Ra) and large mammal herbivory (with camera traps and dung counts) over a ∼2‐year period. We found strong seasonality in all carbon cycling variables and herbivory, peaking during the warm, wet monsoon period. Carbon was produced more efficiently in the thinned stands, with carbon use efficiency (CUE = NPP/GPP) of ∼0.63, versus the unthinned stand with CUE of 0.38. GPP was similar in the two thinned stands (∼3.5 Mg C ha−1 yr−1) but was about 30% greater in the unthinned stands (5.0 Mg C ha−1 yr−1). Finally, the thinned stand had higher understory NPP, large herbivore consumption and had triple the total energy going into primary consumers. Overall, the thinning, and the return to a more natural prefire suppression forest structure, increased the CUE and energy flow from primary producers to primary consumers.

Restoration Thinning in a Drought‐Prone Idaho Forest Creates a Persistent Carbon Deficit

AbstractWestern US forests represent a carbon sink that contributes to meeting regional and global greenhouse gas targets. Forest thinning is being implemented as a strategy for reducing forest vulnerability to disturbance, including mortality from fire, insects, and drought, as well as protecting human communities. However, the terrestrial carbon balance impacts of thinning remain uncertain across regions, spatiotemporal scales, and treatment types. Continuous and in situ long‐term measurements of partial harvest impacts to stand‐scale carbon and water cycle dynamics are nonetheless rare. Here, we examine post‐thinning carbon and water flux impacts in a young ponderosa pine forest in Northern Idaho. We examine in situ stock and flux impacts during the 3 years after treatment as well as simulate the forest sector carbon balance through 2050, including on and off‐site net emissions. During the observation period, increases in tree‐scale net primary production (NPP) and water use persistence through summer drought did not overcome the impacts of density reduction, leading to 45% annual reductions of NPP. Growth duration remained constrained by summer drought in control and thinned stands. Ecosystem model and life cycle assessment estimates demonstrated a net forest sector carbon deficit relative to control stands of 27.0 Mg C ha−1 in 2050 due to emissions from dead biomass pools despite increases to net ecosystem production. Our results demonstrate dynamics resulting in carbon losses from forest thinning, providing a baseline with which to inform landscape‐scale modeling and assess tradeoffs between harvest losses and potential gains from management practices.

Can Payments for Watershed Services Help Advance Restoration of Longleaf Pine? A Critically Engaged Research Approach

Private forests in the southeastern US are critical for providing a variety of ecosystem services, including timber production and water resource protection. Restoration of longleaf pine (LLP) forests and savannas tends to enhance some ecosystem services, including water supply, over timber production. A variety of payments for watershed services (PWS) strategies have emerged to address the market failure associated with private forests and public water supply. The nature of these programs suggests that biodiversity protection may be a positive externality, or third-party benefit, to water resource protection. This paper uses a critically engaged research approach and expert interviews to investigate how PWS programs may help prevent land use change and promote LLP restoration. We also offer recommendations on how to sustain emerging efforts to implement PWS strategies while including LLP restoration objectives.

First report of leaf blight caused by Phytophthora ramorum on periwinkle (Vinca minor) in Washington State, USA.

Phytophthora ramorum (Werres, De Cock & Man in't Veld) was recovered from symptomatic foliage of periwinkle at a botanical garden in WA in March 2015. Symptoms were tan colored lesions with a dark brown margin visible on both surfaces of the leaf and were found on wounds or around leaf margins. Periwinkle is native to Europe and is commonly used for ground cover in ornamental landscapes. It is known to be invasive in US forests near the urban/wildland interface. Potential spread of P. ramorum into WA forests is of regulatory concern, as well as long distance spread to other states via nursery stock (7 CFR §301.92-2). Phytophthora ramorum was isolated from symptomatic foliage by excising leaf pieces 4-6 mm in diameter and surface-sterilizing in 0.6% sodium hypochlorite followed by two rinses in sterile water. Leaf pieces were plated on PARP medium (Ferguson and Jeffers 1999) and after 2-3 days at 20°C, slow-growing dense colonies with coralloid hyphae were isolated onto V8 agar. Colony morphology and chlamydospore production were consistent with descriptions of P. ramorum (Werres et al. 2001), except that the isolate was slower growing and had irregular, non-wildtype morphology (Elliott et al. 2018) compared to other isolates of P. ramorum. ITS and COX1 regions of mycelial DNA was amplified and sequenced to confirm the identity of P. ramorum using primers ITS1/ITS4 (White et al. 1990) and COX1F1/COX1R1 (Van Poucke et al. 2012). Sequences were submitted to GenBank (accession nos. ITS MT031975, COX1 MT031974). BLAST results showed at least 98% similarity with sequences of P. ramorum (ITS, MN540640 [98%]; COX1, EU124920 [100%]), and belonged to the NA1 clonal lineage. Pathogenicity of P. ramorum to periwinkle was confirmed by completing Koch's Postulates. Inoculum was grown on V8 agar plates at 20°C for two weeks until sporangia were abundant. A zoospore suspension was produced by flooding plates with 7 ml sterile water, incubating for 2 hours at 5°C, then for an additional hour at 24°C. Zoospores were observed under the microscope and quantified with a hemocytometer, then diluted to 2 x 105 zoospores/ml. A 10 µl droplet of inoculum was placed at one wounded and one unwounded site on six leaves on each of four plants. In addition, a set of four plants was inoculated by dipping foliage on one branch per plant into the zoospore suspension for 30 seconds. A set of four control plants were mock inoculated in the same manner using sterile water. The trial was repeated once. Inoculated plant materials were incubated in a moist chamber for 3-5 days and free moisture was present on foliage upon removal. Plants were held in a biocontainment chamber (USDA-APHIS permit # 65857) at 20C and symptom development assessed after 7 days (Figure S1). . Symptoms developed on foliage inoculated using both methods in both trials. Phytophthora ramorum was isolated once from droplet inoculated foliage at a wounded site on one plant. Reisolation onto PARP and then V8 agar was conducted from surface-sterilized symptomatic tissue and the presence of P. ramorum confirmed by observation of colony morphology and chlamydospore production. The presence of P. ramorum was also confirmed with DNA extraction from symptomatic foliage from plants from each of the two trials followed by PCR and sequencing of the COX1 gene (EU124920, 100%) (Figure S2). None of the water-inoculated controls were positive for P. ramorum. Low isolation success could be attributed to reduced pathogenicity due to being a non-wildtype isolate. Acknowledgements This work was supported by the USDA National Institute of Food and Agriculture, McIntire-Stennis project 1019284 and USDA APHIS Cooperative Agreement AP17PPQS&T00C070.

Quantifying ecological variation across jurisdictional boundaries in a management mosaic landscape

ContextLarge landscapes exhibit natural heterogeneity. Land management can impose additional variation, altering ecosystem patterns. Habitat characteristics may reflect these management factors, potentially resulting in habitat differences that manifest along jurisdictional boundaries.ObjectivesWe characterized the patchwork of habitats across a case study landscape, the Grand Canyon Protected Area-Centered Ecosystem. We asked: how do ecological conditions vary across different types of jurisdictional boundaries on public lands? We hypothesized that differences in fire and grazing, because they respond to differences in management over time, contribute to ecological differences by jurisdiction.MethodsWe collected plot-scale vegetation and soils data along boundaries between public lands units surrounding the Grand Canyon. We compared locations across boundaries of units managed differently, accounting for vegetation type and elevation differences that pre-date management unit designations. We used generalized mixed effects models to evaluate differences in disturbance and ecology across boundaries.ResultsJurisdictions varied in evidence of grazing and fire. After accounting for these differences, some measured vegetation and soil properties also differed among jurisdictions. The greatest differences were between US Forest Service wilderness and Bureau of Land Management units. For most measured variables, US Forest Service non-wilderness units and National Park Service units were intermediate.ConclusionsIn this study, several ecological properties tracked jurisdictional boundaries, forming a predictable patchwork of habitats. These patterns likely reflect site differences that pre-date jurisdictions as well as those resulting from different management histories. Understanding how ecosystem differences manifest at jurisdictional boundaries can inform resource management, conservation, and cross-boundary collaborations.

Effect magnitudes of operational-scale partial harvesting on residual tree growth and mortality of ten major tree species in Maine USA

Silvicultural systems based on partial harvesting (PH) have become increasingly common in areas historically dominated by clearcut-based systems in response to ecological and social concerns. Current knowledge about the effects of PH is based primarily on stand responses from controlled experiments from limited number of sites. A broader scope of inference is needed to fully understand the effects of PH when applied operationally at a landscape scale. We used 835 permanent monitoring plots from the US Forest Service Forest Inventory and Analysis network to quantify the effect magnitude (EM) of low- (5–40% basal area removal) and high-intensity (41–80% basal area removal) PH on the periodic diameter growth and mortality of residual trees of ten major tree species in Maine, USA. Our results showed that the EM and timing of statistically significant effect (p < 0.05) of the two intensities of PH varies across species. Tree diameter growth responses to high-intensity PH was rapid and prolonged for sugar maple (Acer saccharum) and American beech (Fagus grandifolia), while other species did not show significant responses for at least five years. High-intensity PH increased mortality of American beech, balsam fir (Abies balsamea), red spruce (Picea rubens), northern white cedar (Thuja occidentalis), and red maple (Acer rubrum), but not for other tree species. No relationship was found between species shade tolerance and species-specific response magnitude to PH in terms of diameter growth and tree- or stand-level (absolute or relative) mortality. This result suggests that species shade tolerance does not always determine the type or magnitude of response that a given species has to increased resource availability following PH and that other functional traits may be more important. Overall, the findings provide strong evidence that subsequent tree responses to PH are not consistent among contrasting species for at least 15 years following harvest and longer-term regional assessments are needed.

TreeMap, a tree-level model of conterminous US forests circa 2014 produced by imputation of FIA plot data

A 30 × 30m-resolution gridded dataset of forest plot identifiers was developed for the conterminous United States (CONUS) using a random forests machine-learning imputation approach. Forest plots from the US Forest Service Forest Inventory and Analysis program (FIA) were imputed to gridded c2014 landscape data provided by the LANDFIRE project using topographic, biophysical, and disturbance variables. The output consisted of a raster map of plot identifiers. From the plot identifiers, users of the dataset can link to a number of tree- and plot-level attributes stored in the accompanying tables and in the publicly available FIA DataMart, and then produce maps of any of these attributes, including number of trees per acre, tree species, and forest type. Of 67,141 FIA plots available, 62,758 of these (93.5%) were utilized at least once in imputation to 2,841,601,981 forested pixels in CONUS. Continuous high-resolution forest structure data at a national scale will be invaluable for analyzing carbon dynamics, habitat distributions, and fire effects.

Influence of Fluid Delivery Schedule and Composition on Fluid Balance, Physiologic Strain, and Substrate Use in the Heat

Wildfire suppression is characterized by high total energy expenditure and water turnover rates. Hydration position stands outline hourly fluid intake rates. However, dose interval remains ambiguous. We aimed to determine the effects of microdosing and bolus-dosing water and microdosing and bolus-dosing carbohydrate-electrolyte solutions on fluid balance, heat stress (physiologic strain index [PSI]), and carbohydrate oxidation during extended thermal exercise. In a repeated-measures cross-over design, subjects completed four 120-min treadmill trials (1.3 m·s-1, 5% grade, 33°C, 30% relative humidity) wearing a US Forest Service wildland firefighter uniform and a 15-kg pack. Fluid delivery approximated losses calculated from a pre-experiment familiarization trial, providing 22 doses·h-1 or 1 dose·h-1 (46±11, 1005±245 mL·dose-1). Body weight (pre- and postexercise) and urine volume (pre-, during, and postexercise) were recorded. Heart rate, rectal temperature, skin temperature, and steady-state expired air samples were recorded throughout exercise. Statistical significance (P<0.05) was determined via repeated-measures analysis of variance. Total body weight loss (n=11, -0.6±0.3 kg, P>0.05) and cumulative urine output (n=11, 677±440 mL, P>0.05) were not different across trials. The micro-dosed carbohydrate-electrolyte trial sweat rate was lower than that of the bolus-dosed carbohydrate-electrolyte, bolus-dosed water, and microdosed water trials (n=11, 0.8±0.2, 0.9±0.2, 0.9±0.2, 0.9±0.2 L·h-1, respectively; P<0.05). PSI was lower at 60 than 120 min (n=12, 3.6±0.7 and 4.5±0.9, respectively; P<0.05), with no differences across trials. The carbohydrate-electrolyte trial's carbohydrate oxidation was higher than water trial's (n=12, 1.5±0.3 and 0.8±0.2 g·min-1, respectively; P<0.05), with no dosing style differences. Equal-volume diverse fluid delivery schedules did not affect fluid balance, PSI, or carbohydrate oxidation during extended thermal work.

Quantitative Models of Fungi Interaction--based on Logistic models

As the key medium for decomposing wood fibers, fungi play a vital role in promoting the carbon cycle. The purpose of this paper is to establish mathematic models describing the process of fungi decomposing litter and wood fiber. The paper comprehensively consider the effects of temperature, moisture, location and other factors on fungal traits, and introduced the experimental data of the US Forest Service Center for Forest Mycology Research (CFMR).Based on the model of competition among populations and the modern coexistence theory, this paper establishes the competitive model between two fungi, then generalizes it to a variety of fungi and predicts the short-term and long-term effects.

Contrasting prescription burning and wildfires in California Sierra Nevada national parks and adjacent national forests

History of prescription burning and wildfires in the three Sierra Nevada National Park Service (NPS) parks and adjacent US Forest Service (USFS) forests is presented. Annual prescription (Rx) burns began in 1968 in Sequoia and Kings Canyon National Parks, followed by Yosemite National Park and Lassen Volcanic National Park. During the last third of the 20th century, USFS national forests adjacent to these parks did limited Rx burns, accounting for very little area burned. However, in 2004, an aggressive annual burn program was initiated in these national forests and in the last decade, area burned by planned prescription burns, relative to area protected, was approximately comparable between these NPS and USFS lands. In 1968, the NPS prescription burning program was unique because it coupled planned Rx burns with managing many lightning-ignited fires for resource benefit. From 1968 to 2017, these natural fires managed for resource benefit averaged the same total area burned as planned Rx burns in the three national parks; thus, they have had a substantial impact on total area burned by prescription. In contrast, on USFS lands, most lightning-ignited fires have been managed for suppression, but increasing attention is being paid to managing wildfires for resource benefit.

Experimental manipulation of fuel structure to evaluate the potential ecological effects of fire

A better understanding of how dominant fuels affect fire behavior can improve predictions and comparisons of the ecological effects of fires in forests and other ecosystems. Current methods for evaluating effects of fuel characteristics on fire behavior, including maximum temperature and heating duration, range from small-scale laboratory to large-scale field experiments. Small-scale experiments often have many replicates and high measurement precision but can lack realism, while field experiments may have few replicates and lower measurement precision, thereby making comparisons across ecosystems difficult. Here, we present a method to experimentally evaluate ecological effects of fire while maintaining realism in fuel structure. We applied the method to investigate fire behavior effects of cogongrass (Imperata cylindrica), an invasive grass with a vertical growth form that is widespread across Southeast US forests. Examining the effect of fuel structure (piled vs. standing) on fire behavior for a range of fuel loads illustrated how more realistic standing fuels produced shorter heating duration (s above 100 °C), taller flame heights, and faster spread rates compared to piled fuels. Average heating duration was ~2–4 times longer and ranged more widely when fuels were piled (80–277 s) compared to standing (41–57 s). Flame heights were ~1.4 times taller when fuels were standing than piled. These differences highlight that maintaining natural fuel structure in experimental fires produces more realistic estimates of fire behavior and effects. Consequently, not maintaining realistic vertical fuel structure could lead to overestimation of potential fire impacts related to temperature (e.g., tissue damage) but underestimate potential impacts related to flame heights, such as total engulfment of tree seedlings and saplings by fire. Altogether, our method effectively maintained fuel structure, enabling assessment of more probable fire behavior and impacts of the invasive grass than if fuels were simply piled. This approach may help further bridge the gap in realism between small-scale experiments and large-scale fires, enabling comparisons of the ecological effects of fires and fire-invasion interactions across forest ecosystems.

A Comprehensive Forest Biomass Dataset for the USA Allows Customized Validation of Remotely Sensed Biomass Estimates

There are several new and imminent space-based sensors intended to support mapping of forest structure and biomass. These instruments, along with advancing cloud-based mapping platforms, will soon contribute to a proliferation of biomass maps. One means of differentiating the quality of different maps and estimation strategies will be comparison of results against independent field-based estimates at various scales. The Forest Inventory and Analysis Program of the US Forest Service (FIA) maintains a designed sample of uniformly measured field plots across the conterminous United States. This paper reports production of a map of statistical estimates of mean biomass, created at approximately the finest scale (64,000-hectare hexagons) allowed by FIA’s sample density. This map may be useful for assessing the accuracy of future remotely sensed biomass estimates. Equally important, fine-scale mapping of FIA estimates highlights several ways in which field- and remote sensing-based methods must be aligned to ensure comparability. For example, the biomass in standing dead trees, which may or may not be included in biomass estimates, represents a source of potential discrepancy that FIA shows to be particularly important in the Western US. Likewise, alternative allometric equations (which link measurable tree dimensions such as diameter to difficult-to-measure variables like biomass) strongly impact biomass estimates in ways that can vary over short distances. Potential mismatch in the conditions counted as forests also varies greatly over space. Field-to-map comparisons will ideally minimize these sources of uncertainty by adopting common allometry, carbon pools, and forest definitions. Our national hexagon-level benchmark estimates, provided in Supplementary Files, therefore addresses multiple pools and allometric approaches independently, while providing explicit forest area and uncertainty information. This range of information is intended to allow scientists to minimize potential discrepancies in support of unambiguous validation.

Analytical review of modern studies of changes in the biotic components of the carbon cycle

The research on changes in the spatial-temporal dynamics of carbon in natural ecosystems on land is explored. The works of Russian and foreign authors on the analysis of the depositing ability of the cover are presented. Works on biomass reserves and primary production of biogeocenoses, research in the field of mathematical modeling of the carbon cycle in terrestrial ecosystems using remote sensing data are described. The article discusses modern approaches to mathematical modeling of productive processes and biological cycles of elements in plant ecosystems. The contribution of Russian and foreign authors to the spatial-temporal dynamics of carbon is analyzed. The research data in the assessment of the sequestration capacity of plant ecosystems, as the role of an ecosystem function, performing the function of a climatic ensemble of the state of the atmosphere is given. The various modeling-based methods for assessing and forecasting carbon stocks in forests, which have received international recognition, are presented, and the role of climate in managed forests in mitigating changes and predicting their carbon storage potential for the period up to 2050 under different forest management scenarios is examined. Among them: ISIS IIASA (Austria), EFIMOD + ROMUL (Russia), ROBUL (Russia), Information System for Determination and Mapping of Carbon Deposition by Forests (Russia, UGFTU), CBM-CFS3 (Canadian Forest Service), FORCARB2 (US Forest Service). The works based on the spatial model of the carbon cycle in the atmosphere - plant - soil system (A.M. Tarko) of the Computing Center of the Russian Academy of Sciences, used to assess the absorption potential in various regions of the world, are outlined.