LAND USE AND LAND COVER CHANGE AS A DRIVER OF ECOSYSTEM DEGRADATION ACROSS BIOMES

The expansion and intensification of agricultural production in human-dominated landscapes threaten efforts to sustain natural ecosystems and maintain agricultural production in a changing climate. Long-term use of agricultural lands, combined with conversion of natural ecosystems for agricultural production, can rapidly degrade the health of remaining natural ecosystems. The fundamental goal of this dissertation was to assess the impacts of anthropogenic degradation on stocks and sequestration of carbon. Although degradation alters a range of ecosystem services, case studies of ecosystem degradation in this dissertation focus on reductions in vegetation productivity, carbon stocks, and the extent of natural forest cover as a result of human activity. Time series of satellite remote sensing data were used to track forest and rangeland degradation in the southwestern United States, forest carbon emissions from cropland expansion in the Brazilian Cerrado, and fire-driven forest conversion for oil palm plantations in Southeast Asia. Three major themes link the regional case studies: expansion and intensification of agricultural production, market demand and certification, and agricultural management in response to climate variability. Conclusions from the dissertation underscore the widespread influence of land management on vegetation productivity and forest carbon stocks. In the Southwest United States, reductions in net primary production on managed lands were higher in forested landscapes than other cover types. In contrast, Native American Indian Reservations, often considered to be more degraded, actually had smaller absolute reductions in net primary productivity during 2000-2011. Multi-year droughts in the southwest present new challenges for managing forests and rangelands, and climate projections suggest dry conditions will intensify in the coming century. In Southeast Asia, industry-led efforts to certify sustainable palm oil production were evaluated using satellite data on fires and forest loss. Rates of fire-driven deforestation and total fire activity declined following certification, highlighting the potential for certification to reduce ignitions during El Niño years and protect remaining fragments of lowland and peat forest. Aligning certification criteria for sustainable palm oil with satellite monitoring capabilities may help accelerate compliance with environmental legislation and market demands for deforestation-free products. In Brazil, government and industry actions to limit Amazon deforestation have largely overlooked the neighboring Cerrado biome. Forest carbon emissions from deforestation for soy expansion in the Cerrado increased substantially after the implementation of the Soy Moratorium in the Brazilian Amazon, partially offsetting recent reductions in Amazon deforestation carbon emissions. The success of policies to support sustainable agricultural production therefore depends on efforts to minimize cross-biome leakage and the ability to monitor compliance and unintended consequences. Solutions for management must also confront the growing influence of climate variability. Time series of satellite data may allow early detection of degradation impacts and support efforts to mitigate the influence of sustained agricultural production on natural systems. Changes in vegetation carbon stocks from ecosystem degradation varied across case studies, underscoring the diverse nature of direct and indirect drivers of degradation across different land use systems. Direct human drivers of ecosystem degradation in the southwest United States from management of livestock grazing resulted in gradual changes in vegetation productivity, whereas mining and oil extraction areas showed large and permanent reductions. Forest carbon emissions from agriculture expansion in the Cerrado were a one-time process, as native vegetation is cleared for cropland expansion. In contrast, the carbon emissions from Southeast Asia’s forest and peatland conversion involve both sudden and gradual processes, as carbon accumulation in oil palm plantations partially compensates for emissions from forest conversion. Overall, this research made contributions to understanding of the regional impacts of human activity and the potential for climate change mitigation from sustainable land use practices in human-dominated landscapes

Effect of oil palm sustainability certification on deforestation and fire in Indonesia.

Many major corporations and countries have made commitments to purchase or produce only "sustainable" palm oil, a commodity responsible for substantial tropical forest loss. Sustainability certification is the tool most used to fulfill these procurement policies, and around 20% of global palm oil production was certified by the Roundtable on Sustainable Palm Oil (RSPO) in 2017. However, the effect of certification on deforestation in oil palm plantations remains unclear. Here, we use a comprehensive dataset of RSPO-certified and noncertified oil palm plantations (∼188,000 km2) in Indonesia, the leading producer of palm oil, as well as annual remotely sensed metrics of tree cover loss and fire occurrence, to evaluate the impact of certification on deforestation and fire from 2001 to 2015. While forest loss and fire continued after RSPO certification, certified palm oil was associated with reduced deforestation. Certification lowered deforestation by 33% from a counterfactual of 9.8 to 6.6% y-1 Nevertheless, most plantations contained little residual forest when they received certification. As a result, by 2015, certified areas held less than 1% of forests remaining within Indonesian oil palm plantations. Moreover, certification had no causal impact on forest loss in peatlands or active fire detection rates. Broader adoption of certification in forested regions, strict requirements to avoid all peat, and routine monitoring of clearly defined forest cover loss in certified and RSPO member-held plantations appear necessary if the RSPO is to yield conservation and climate benefits from reductions in tropical deforestation

An irrigated area map of the world (1999) derived from remote sensing

Remote sensing / Mapping / GIS / Irrigated sites / Estimation

Global Characterization and Monitoring of Forest Cover Using Landsat Data: Opportunities and Challenges

The compilation of global Landsat data-sets and the ever-lowering costs of computing now make it feasible to monitor the Earth's land cover at Landsat resolutions of 30 m. In this article, we describe the methods to create global products of forest cover and cover change at Landsat resolutions. Nevertheless, there are many challenges in ensuring the creation of high-quality products. And we propose various ways in which the challenges can be overcome. Among the challenges are the need for atmospheric correction, incorrect calibration coefficients in some of the data-sets, the different phenologies between compilations, the need for terrain correction, the lack of consistent reference data for training and accuracy assessment, and the need for highly automated characterization and change detection. We propose and evaluate the creation and use of surface reflectance products, improved selection of scenes to reduce phenological differences, terrain illumination correction, automated training selection, and the use of information extraction procedures robust to errors in training data along with several other issues. At several stages we use Moderate Resolution Spectroradiometer data and products to assist our analysis. A global working prototype product of forest cover and forest cover change is included

Corrigendum: Assessing the potential additionality of certification by the Round table on Responsible Soybeans and the Roundtable on Sustainable Palm Oil (2016 Environ. Res. Lett. 11 045003)

ISSN:1748-9326ISSN:1748-931

Assessing the potential additionality of certification by the Round table on Responsible Soybeans and the Roundtable on Sustainable Palm Oil

Multi-stakeholder roundtables offering certification programs are promising voluntary governance mechanisms to address sustainability issues associated with international agricultural supply chains. Yet, little is known about whether roundtable certifications confer additionality, the benefits of certification beyond what would be expected from policies and practices currently in place. Here, we examine the potential additionality of the Round table on Responsible Soybeans (RTRS) and the Roundtable on Sustainable Palm Oil (RSPO) in mitigating conversion of native vegetation to cropland. We develop a metric of additionality based on business as usual land cover change dynamics and roundtable standard stringency relative to existing policies. We apply this metric to all countries with RTRS (n = 8) and RSPO (n = 12) certified production in 2013–2014, as well as countries that have no certified production but are among the top ten global producers in terms of soy (n = 2) and oil palm (n = 2). We find RSPO and RTRS both have substantially higher levels of stringency than existing national policies except in Brazil and Uruguay. In regions where these certification standards are adopted, the mean estimated rate of tree cover conversion to the target crop is similar for both standards. RTRS has higher mean relative stringency than the RSPO, yet RSPO countries have slightly higher enforcement levels. Therefore, mean potential additionality of RTRS and RSPO is similar across regions. Notably, countries with the highest levels of additionality have some adoption. However, with extremely low adoption rates (0.41% of 2014 global harvested area), RTRS likely has lower impact than RSPO (14%). Like most certification programs, neither roundtable is effectively targeting smallholder producers. To improve natural ecosystem protection, roundtables could target adoption to regions with low levels of environmental governance and high rates of forest-to-cropland conversion.ISSN:1748-9326ISSN:1748-931

Assessing the potential additionality of certification by the Round table on Responsible Soybeans and the Roundtable on Sustainable Palm Oil

Multi-stakeholder roundtables offering certification programs are promising voluntary governance mechanisms to address sustainability issues associated with international agricultural supply chains. Yet, little is known about whether roundtable certifications confer additionality, the benefits of certification beyond what would be expected from policies and practices currently in place. Here, we examine the potential additionality of the Round table on Responsible Soybeans (RTRS) and the Roundtable on Sustainable Palm Oil (RSPO) in mitigating conversion of native vegetation to cropland. We develop a metric of additionality based on business as usual land cover change dynamics and roundtable standard stringency relative to existing policies. We apply this metric to all countries with RTRS ( n  = 8) and RSPO ( n  = 12) certified production in 2013–2014, as well as countries that have no certified production but are among the top ten global producers in terms of soy ( n  = 2) and oil palm ( n  = 2). We find RSPO and RTRS both have substantially higher levels of stringency than existing national policies except in Brazil and Uruguay. In regions where these certification standards are adopted, the mean estimated rate of tree cover conversion to the target crop is similar for both standards. RTRS has higher mean relative stringency than the RSPO, yet RSPO countries have slightly higher enforcement levels. Therefore, mean potential additionality of RTRS and RSPO is similar across regions. Notably, countries with the highest levels of additionality have some adoption. However, with extremely low adoption rates (0.41% of 2014 global harvested area), RTRS likely has lower impact than RSPO (14%). Like most certification programs, neither roundtable is effectively targeting smallholder producers. To improve natural ecosystem protection, roundtables could target adoption to regions with low levels of environmental governance and high rates of forest-to-cropland conversion