Sandra Brown

• PhD
• Senior Researcher at Winrock International

Background Locating terrestrial sources and sinks of carbon (C) will be critical to developing strategies that contribute to the climate change mitigation goals of the Paris Agreement. Here we present spatially resolved estimates of net C change across United States (US) forest lands between 2006 and 2010 and attribute them to natural and anthropog...

Publication details, including instructions for authors and subscription information: The carbon market is touted as offering developing countries major new opportunities to achieve sustainable development while simultaneously helping the global community to combat climate change. The prospect is that implementing carbon offset projects and program...

Aim: The accurate mapping of forest carbon stocks is essential for understanding the global carbon cycle, for assessing emissions from deforestation, and for rational land-use planning. Remote sensing (RS) is currently the key tool for this purpose, but RS does not estimate vegetation biomass directly, and thus may miss significant spatial variati...

Aim: The accurate mapping of forest carbon stocks is essential for understanding the global carbon cycle, for assessing emissions from deforestation, and for rational land-use planning. Remote sensing (RS) is currently the key tool for this purpose, but RS does not estimate vegetation biomass directly, and thus may miss significant spatial variatio...

The focus of land-use related efforts in developing countries to reduce carbon emissions has been on slowing deforestation, yet international agreements are to reduce emissions from both deforestation and forest degradation (REDD). The second ‘D’ is poorly understood and accounted for a number of technical and policy reasons. Here we introduce a co...

A sourcebook of methods and procedures for monitoring and reporting anthropogenic greenhouse gas emissions and removals associated with deforestation, gains and losses of carbon stocks in forests remaining forests, and forestation

There is general consensus that carbon (C) sequestration projects in forests are a relatively low cost option for mitigating climate change, but most studies on the subject have assumed that transaction costs are negligible. The objectives of the study were to examine transaction costs for forest C sequestration projects and to determine the signif...

Ambiguous definitions and metrics create risks for forest conservation and accountability.

Mapping the aboveground biomass of tropical forests is essential both for implementing conservation policy and reducing uncertainties in the global carbon cycle. Two medium resolution (500m -- 1000m) pantropical maps of vegetation biomass have been recently published, and have been widely used by sub-national and national-level activities in relati...

A strong consensus is building on the need to slow the rate of climate change. Emissions must be reduced, and where emission reductions are not financially feasible, mechanisms need to be in place to allow investment in reductions in neighboring areas, neighboring countries, and across the Earth. Forests have a large potential role to play in this...

Policies to reduce emissions from deforestation would benefit from clearly derived, spatially explicit, statistically bounded estimates of carbon emissions. Existing efforts derive carbon impacts of land-use change using broad assumptions, unreliable data, or both. We improve on this approach using satellite observations of gross forest cover loss...

The Regional Greenhouse Gas Initiative for the northeastern states of the U.S. allows for terrestrial carbon (C) sequestration offsets generated by afforestation activities only. This paper estimates the maximum potential quantity and associated costs of increasing the storage of carbon by afforestation of existing agricultural land in the 11 state...

Developing countries are required to produce robust estimates of forest carbon stocks for successful implementation of climate change mitigation policies related to reducing emissions from deforestation and degradation (REDD). Here we present a "benchmark" map of biomass carbon stocks over 2.5 billion ha of forests on three continents, encompassing...

Stand tables from forest inventories representing more than 22 × 106 ha of forests in tropical Asia were used to estimate aboveground biomass (point and 99% confidence interval). The mean inventory-based biomass for moist forests (225 Mg/ha) was lower than that reported by direct measurements for mature forests in the same region (350 Mg/ha), where...

To determine the present and future role of tropical tree plantations in the global carbon budget, data on rates of plantation establishment and their commercial volumes, by species groups and age-classes, were gathered and converted to biomass and ultimately to carbon fluxes. The rate of plantation establishment has increased dramatically since th...

To accurately and precisely measure the carbon in forests is gaining global attention as countries seek to comply with agreements under the UN Framework Convention on Climate Change. Efforts to mitigate the climate change from the Reduced Emissions from Deforestation and Degradation (REDD) depend on the ability of mapping and monitoring forest area...

Background/Question/Methods Deforestation and forest degradation in developing countries significantly impacts the accumulation of greenhouse gases in the atmosphere. Although tropical deforestation and forest degradation are significant contributors to carbon emissions, activities to reduce such emissions were not accepted under the Kyoto Protocol...

International negotiations on the inclusion of land use activities into an emissions reduction system for the UN Framework Convention on Climate Change (UNFCCC) have been partially hindered by the technical challenges of measuring, reporting, and verifying greenhouse gas (GHG) emissions and the policy issues of leakage, additionality, and permanenc...

REDD+ projects have played a limited role in the voluntary carbon market. This has not been for lack of interest by investors, but rather the result of the slow process by which methodologies are being developed and approved for the monitoring, reporting, and verification of offsets. Differences in the methodology process among different registries...

Climate change is occurring with greater speed and intensity that previously anticipated. All effective environmentally and socially sound mitigation efforts need to be employed to effectively address this global crisis. Land Use, Land Use Change and Forestry (LULUCF) projects can provide significant climate change mitigation benefits as well as po...

The motivations for substantive inclusion of forest carbon in greenhouse gas abatement efforts are strong. For starters, forest carbon projects can be implemented immediately and do not need any new technologies, and the science behind estimating their carbon benefits is robust. Secondly, the projects are unique in that they can positively impact t...

The Nature Conservancy participated in a Cooperative Agreement with the Department of Energy (DOE) National Energy Technology Laboratory (NETL) to explore the compatibility of carbon sequestration in terrestrial ecosystems and the conservation of biodiversity. The title of the research project was “Application and Development of Appropriate Tools a...

No mandatory national program currently exists to mitigate climate change in the US Consequently, voluntary programs and mandatory state-level programs are multiplying to allow users to register emission-offset activities, creating multiple often contradictory measurement and recording standards.For the land use sector we examined a hypothetical pr...

A number of studies have suggested that incentives for carbon sequestration could lead to longer rotation periods for even-aged managed forests. In this article we examine the potential costs and quantity of sequestered carbon from extending rotation ages in softwood forests of the southern and western USA. A model of optimal rotations when carbon...

International discussions on reducing emissions from deforestation and degradation (REDD) as a greenhouse gas (GHG) abatement strategy are ongoing under the United Nations Framework Convention on Climate Change (UNFCCC). In the light of these discussions, it behooves countries to be able to determine the relative likelihood of deforestation over a...

Down and dead-wood plays an important ecological role in forest ecosystems, and the decomposition of this material may contribute significantly to forest net ecosystem production. Dead-wood decomposition can be measured in three ways: measuring variability in density over a chronosequence of dead-wood, measuring density changes during a time series...

EXECUTIVE SUMMARY Nitrogen fertilizers represent the dominant cause of greenhouse gas emissions from agricultural crop production. In 2007 nitrous oxide from agricultural soil management was responsible for 3.4% of net US emissions. The purpose of the study was to develop a methodology that could be used to calculate emission reduction offsets from...

Reducing carbon emissions from deforestation and degradation in developing countries is of central importance in efforts to combat climate change. Key scientific challenges must be addressed to prevent any policy roadblocks. Foremost among the challenges is quantifying nations' carbon emissions from deforestation and forest degradation, which requi...

Forests, grasslands and agricultural lands across the United States play an integral role in the carbon balance of the nation. Trees and plants take up carbon dioxide—the major greenhouse gas—and store the carbon in leaves, branches, trunks, stems, and roots. Protecting terrestrial ecosystems or improving the way they are managed can reduce carbon...

Amounts and costs of potential terrestrial carbon sequestration are provided at the county level for 11 states that make up the Northeast region of the United States. Activities analyzed include afforestation of both cropland and pasture, no-till agriculture, non-cultivated crops, restocking of forest lands, extending rotations for timber extractio...

The complexities inherent in land use, land-use change and forestry (LULUCF) activities have led to contentious and prolonged debates about the merits of their inclusion in the 2008–2012 first commitment period of the Kyoto Protocol. Yet the inclusion of these activities played a key role in agreement on the general framework of the Kyoto Protocol,...

In response to the United Nations Framework Convention on Climate Change (UNFCCC) process investigating the technical issues surrounding the ability to reduce greenhouse gas (GHG) emissions from deforestation in developing countries, this paper reviews technical capabilities for monitoring deforestation and estimating emissions. Implementation of p...

Many pathways have been proposed for including land use in a post-2012 climate agreement. Several involve new accounting structures which are quite different from the rules established in the Marrakech Accords and related decisions. However, a mechanism based largely on the structure agreed for the first commitment period also has its benefits. Thi...

Although forest conservation activities, particularly in the tropics, offer significant potential for mitigating carbon (C) emissions, these types of activities have faced obstacles in the policy arena caused by the difficulty in determining key elements of the project cycle, particularly the baseline. A baseline for forest conservation has two mai...

Development in the tropics usually is associated with deforestation, and it is important to understand the dimensions of this development, its driving factors, and possible mitigation schemes. Global interest in tropical forests is more and more focused on their role in the global carbon cycle from the perspective of carbon emissions produced by de...

The complexities inherent in land use, land-use change and forestry (LULUCF) activities have led to contentious and prolonged debates about the merits of their inclusion in the 2008–2012 first commitment period of the Kyoto Protocol. Yet the inclusion of these activities played a key role in agreement on the general framework of the Kyoto Protocol,...

This paper develops a forestland management model for the three states in the South Central United States (Arkansas, Louisiana, and Mississippi). Forest type and land-use shares are estimated to be a function of economic and physical variables. The results suggest that while historically pine plantations in this region have been established largely...

The Nature Conservancy is participating in a Cooperative Agreement with the Department of Energy (DOE) National Energy Technology Laboratory (NETL) to explore the compatibility of carbon sequestration in terrestrial ecosystems and the conservation of biodiversity. The title of the research project is ''Application and Development of Appropriate Too...

The biomass carbon (C) stock of forests is one of key parameters for the study of regional and global carbon cycles. Literature reviews shows that inventory-based forest C stocks documented for major countries in the middle and high northern latitudes fall within a narrow range of 36-56 Mg C ha(-1) with an overall area-weighted mean of 43.6 Mg C ha...

Tropical forests hold large stores of carbon, yet uncertainty remains regarding their quantitative contribution to the global carbon cycle. One approach to quantifying carbon biomass stores consists in inferring changes from long-term forest inventory plots. Regression models are used to convert inventory data into an estimate of aboveground biomas...

Global deforestation and forest degradation rates have a signifi cant impact on the accumulation of greenhouse gases (GHG) in the atmosphere. The Food and Agriculture Organization estimated that during the 1990s 16.1 million hectares per year were affected by deforestation, most of them in the tropics. The Intergovernmental Panel on Climate Change...

The Nature Conservancy is participating in a Cooperative Agreement with the Department of Energy (DOE) National Energy Technology Laboratory (NETL) to explore the compatibility of carbon sequestration in terrestrial ecosystems and the conservation of biodiversity. The title of the research project is ''Application and Development of Appropriate Too...

Previous work found that tree turnover, biomass, and large liana densities increased in mature tropical forests in the late 20th century, indicating a concerted shift in forest ecological processes. However, the findings have proved controversial. Here, regional-scale patterns of tree turnover are characterized, using improved datasets available fo...

Widespread recent changes in the ecology of old-growth tropical forests have been documented, in particular an increase in stem turnover (pan-tropical), and an increase in above-ground biomass (neotropical). Whether these changes are synchronous and whether changes in growth are also occurring is not known. This chapter reports assesses changes fro...

Given the interest in implementing land-use change and forestry projects for mitigating carbon dioxide emissions, there is potentially a large demand for a system to measure carbon stocks accurately and precisely in a cost-effective manner. As terrestrial ecosystems tend to be heterogeneous, a large number of sample plots could be needed to attain...

Effects of human impacts on fine roots and soil organic matter of a pine forest in subtropical China were studied by comparing treatment (harvesting understory and litter according to practice of local people) and control (no harvest) plots in a pine forest from 1990 to 1995. During this studied period, the total amount of material harvested by thi...

Much uncertainty in estimating root biomass density (RBD, root mass per unit area) of all roots regionally exists because of methodological difficulties and little knowledge about the effects of biotic and abiotic factors on the magnitude and distribution pattern of RBD. In this study, we collected field data of RBD from 22 sites along the Tibetan...

Human occupation of the Panama Canal Watershed has affected its land cover for the past century. A rule-based model was developed and applied to estimate changes in land use and subsequent carbon emissions over the next twenty years in the Eastern Panama Canal Watershed (EPCW). Projections show that the highest percent change in land use for the ‘n...

Global deforestation and forest degradation have led to massive loss of biodiversity and decline of ecosystem services. Against this prospect, it is important not only to protect, but also to restore forest ecosystems. The paper analyzes the current and future role of the restoration of forests and degraded lands starting with the definition of var...

Global deforestation and forest degradation rates have a significant impact on the accumulation of greenhouse gases (GHG) in the atmosphere. The Food and Agriculture Organization estimated that during the 1990s 16.1 million hectares per year were affected by deforestation, most of them in the tropics. The Intergovernmental Panel on Climate Change (...

Mathematical proofs show that rate estimates, for example of mortality and recruitment, will decrease with increasing census interval when obtained from censuses of non‐homogeneous populations. This census interval effect could be confounding or perhaps even driving conclusions from comparative studies involving such rate estimates. We quantify thi...

This paper develops methods for estimating leakage from forest-based carbon projects that seek to reduce carbon emissions from timber harvesting in tropical forests. A theoretical framework is presented in which a specific country, in this case Bolivia, is treated as a supplier to the global timber market. Leakage is measured, over a 30- to 50-year...

Previous work has shown that tree turnover, tree biomass and large liana densities have increased in mature tropical forest plots in the late twentieth century. These results point to a concerted shift in forest ecological processes that may already be having significant impacts on terrestrial carbon stocks, fluxes and biodiversity. However, the fi...

Several widespread changes in the ecology of old-growth tropical forests have recently been documented for the late twentieth century, in particular an increase in stem turnover (pan-tropical), and an increase in above-ground biomass (neotropical). Whether these changes are synchronous and whether changes in growth are also occurring is not known....

The Nature Conservancy is participating in a Cooperative Agreement with the Department of Energy (DOE) National Energy Technology Laboratory (NETL) to explore the compatibility of carbon sequestration in terrestrial ecosystems and the conservation of biodiversity. The title of the research project is ''Application and Development of Appropriate Too...

One of the most challenging technical issues associated with project-based mechanisms is that of leakage. A conceptual framework is proposed for the identification and analysis of leakage potentially generated by a project. The categorization of leakage based on the actors responsible for their manifestation is proposed, which divides sources of le...

Through a cooperative agreement with the National Energy Technology Laboratory, The Nature Conservancy is implementing the Climate Action Project Research Initiative to: 1) improve carbon inventory estimates during both planning and implementation phases of projects; 2) devise standardized approaches to estimate project carbon benefits at a reasona...

To investigate the impact of human disturbance and subsequent recovery on soil nitrogen processes, nitrogen availability during different seasons and at two soil depths in disturbed, rehabilitated and mature forests in tropical China was estimated using the ion exchange resin (IER) bag method. Soil total mineral N (NH4+N+NO3−N) varied significant...

To participate in the potential market for carbon credits based on changes in the use and management of the land, one needs to identify opportunities and implement land-use based emissions reductions or sequestration projects. A key requirement of land-based carbon (C) projects is that any activity developed for generating C benefits must be additi...

Presently, the Clean Development Mechanism of the Kyoto Protocol does not allow for crediting of projects that offset carbon dioxide emissions by preventing emissions elsewhere through averted changes in land use (or forestry). Part of the criticism of these types of projects was that projections of "without-project" baselines lacked the scientific...

The paper analyses the role that forests and forest policies may have on reducing greenhouse gas (GHG) emission reduction. It focuses on the integration of forest measures (afforestation, reforestation and forest management) on the provisions of the Kyoto Protocol and the impediments to the implementation of a system of direct incentives to support...

This review places into context the role that forest ecosystems play in the global carbon cycle, and their potential interactions with climate change. We first examine the natural, preindustrial carbon cycle. Every year forest gross photosynthesis cycles approximately one-twelfth of the atmospheric stock of carbon dioxide, accounting for 50% of ter...

The global carbon cycle is significantly influenced by changes in the use and management of forests and agriculture. Humans have the potential through changes in land use and management to alter the magnitude of forest-carbon stocks and the direction of forest-carbon fluxes. However, controversy over the use of biological means to absorb or reduce...

The many opportunities for mitigating atmospheric carbon emissions in developing countries include reforesting degraded lands, implementing sustainable agricultural practices on existing lands and slowing tropical deforestation. This analysis shows that over the next 10 years, 48 major tropical and subtropical developing countries have the potentia...

Worldwide, there are many pilot forestry projects that are under some stage of implementation, and much experience has been gained from them with respect to measuring, monitoring, and accounting for their carbon benefits. Forestry projects have been shown to be easier to quantify and monitor than national inventories, partly because not all pools n...

Large pieces of standing or fallen dead wood, known as coarse woody debris (CWD), play important roles in temperate forest carbon and nutrient cycles, and affect the abundance and distribution of many classes of organisms. CWD biomass and inputs are poorly documented in tropical rain forests (TRF), and the causes for their variation at landscape-sc...

Over the past century almost every ecosystem on Earth has come under the influence of changes in atmospheric composition and climate caused by human activity. Tropical forests are among the most productive and extensive ecosystems, and it has been hypothesized that both the dynamics and biomass of apparently undisturbed, old-growth tropical forests...

To accurately and precisely measure the carbon in forests is gaining global attention as countries seek to comply with agreements under the UN Framework Convention on Climate Change. Established methods for measuring carbon in forests exist, and are best based on permanent sample plots laid out in a statistically sound design. Measurements on trees...

To improve estimates of the state and change in C pools due to changes in land use in tropical forests of Africa, we combined spatially explicit estimates of biomass C density, obtained by modelling in a geographical information system (GIS), with new data on the area of forests (woody formations with a minimum of 10% crown cover) reported at subna...