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Washington, DC, United States

Caviglia-Harris J.L.,Salisbury University | Toomey M.,ASRC Federal InuTeq | Harris D.W.,Salisbury University | Mullan K.,University of Montana | And 3 more authors.
Journal of Land Use Science | Year: 2014

Land uses that replace tropical forests are important determinants of terrestrial carbon storage and biodiversity. This includes secondary forest growth after deforestation, which has been integrated into the REDD+ (Reducing Emissions from Deforestation and Forest Degradation) concept as a means to enhance current forest carbon stocks. Incorporating secondary forest into climate change mitigation efforts requires both accurate measurements and a means to target interventions to achieve additionality. We demonstrate how remote sensing and household survey data can be combined to meet these requirements in 'old frontiers' of the Brazilian Amazon and introduce the idea that annual land-cover transitions - measured at the pixel level and over time - can serve as leading indicators of secondary forest regrowth. The patterns we observe are consistent with the suggested tension between equity and additionality in REDD+: the poorest households on the poorest quality lots already allow forest regeneration. Policy interventions to encourage regeneration are likely to have the greatest additional impact on higher quality lots owned by better capitalized households. © 2014 © 2014 Taylor & Francis.

Huang S.,ASRC Federal InuTeq | Dahal D.,Stinger Ghaffarian Technologies SGT Inc. | Dahal D.,Eros | Liu H.,Washington State University | And 6 more authors.
Canadian Journal of Forest Research | Year: 2015

The albedo change caused by fires and the subsequent succession is spatially heterogeneous, leading to the need to assess the spatiotemporal variation of surface shortwave forcing (SSF) as a component to quantify the climate impacts of high-latitude fires.Weused an image reconstruction approach to compare postfire albedo with the albedo assuming that no fires had occurred. Combining the fire-caused albedo change from the 2001–2010 fires in interior Alaska and the monthly surface incoming solar radiation, we examined the spatiotemporal variation of SSF in the early successional stage of approximately 10 years. Our results showed that although postfire albedo generally increased in fall, winter, and spring, some burned areas could show an albedo decrease during these seasons. In summer, the albedo increased for several years and then declined again. The spring SSF distribution did not show a latitudinal decrease from south to north as previously reported. The results also indicated that although the SSF is usually largely negative in the early successional years, it may not be significant during the first postfire year. The annual 2005–2010 SSF for the 2004 fire scars was –1.30, –4.40, –3.31, –4.00, –3.42, and –2.47 W·m−2, respectively. The integrated annual SSF map showed significant spatial variation, with a mean of –3.15 W·m−2, a standard deviation of 3.26 watts per square metre (W·m−2), and 16% of burned areas having positive SSF. Our results suggest that boreal deciduous fires would be less positive for climate change than boreal evergreen fires. Future research is needed to comprehensively investigate the spatiotemporal radiative and nonradiative forcings to determine the effect of boreal fires on the climate. © 2015, National Research Council of Canada. All rights reserved.

Vacquie L.A.,Toulouse Jean Jaures University | Houet T.,Toulouse Jean Jaures University | Sohl T.L.,U.S. Geological Survey | Reker R.,ASRC Federal InuTeq | Sayler K.L.,U.S. Geological Survey
Journal of Mountain Science | Year: 2015

Over the last decades and centuries, European mountain landscapes have experienced substantial transformations. Natural and anthropogenic LULC changes (land use and land cover changes), especially agro-pastoral activities, have directly influenced the spatial organization and composition of European mountain landscapes. For the past sixty years, natural reforestation has been occurring due to a decline in both agricultural production activities and rural population. Stakeholders, to better anticipate future changes, need spatially and temporally explicit models to identify areas at risk of land change and possible abandonment. This paper presents an integrated approach combining forecasting scenarios and a LULC changes simulation model to assess where LULC changes may occur in the Pyrenees Mountains, based on historical LULC trends and a range of future socio-economic drivers. The proposed methodology considers local specificities of the Pyrenean valleys, sub-regional climate and topographical properties, and regional economic policies. Results indicate that some regions are projected to face strong abandonment, regardless of the scenario conditions. Overall, high rates of change are associated with administrative regions where land productivity is highly dependent on socio-economic drivers and climatic and environmental conditions limit intensive (agricultural and/or pastoral) production and profitability. The combination of the results for the four scenarios allows assessments of where encroachment (e.g. colonization by shrublands) and reforestation are the most probable. This assessment intends to provide insight into the potential future development of the Pyrenees to help identify areas that are the most sensitive to change and to guide decision makers to help their management decisions. © 2015, Science Press, Institute of Mountain Hazards and Environment, CAS and Springer-Verlag Berlin Heidelberg.

Wylie B.,U.S. Geological Survey | Rigge M.,ASRC Federal InuTeq | Brisco B.,Canada Center For Remote Sensing | Murnaghan K.,Canada Center For Remote Sensing | And 2 more authors.
Remote Sensing | Year: 2014

A warming climate influences boreal forest productivity, dynamics, and disturbance regimes. We used ecosystem models and 250 m satellite Normalized Difference Vegetation Index (NDVI) data averaged over the growing season (GSN) to model current, and estimate future, ecosystem performance. We modeled Expected Ecosystem Performance (EEP), or anticipated productivity, in undisturbed stands over the 2000-2008 period from a variety of abiotic data sources, using a rule-based piecewise regression tree. The EEP model was applied to a future climate ensemble A1B projection to quantify expected changes to mature boreal forest performance. Ecosystem Performance Anomalies (EPA), were identified as the residuals of the EEP and GSN relationship and represent performance departures from expected performance conditions. These performance data were used to monitor successional events following fire. Results suggested that maximum EPA occurs 30-40 years following fire, and deciduous stands generally have higher EPA than coniferous stands. Mean undisturbed EEP is projected to increase 5.6% by 2040 and 8.7% by 2070, suggesting an increased deciduous component in boreal forests. Our results contribute to the understanding of boreal forest successional dynamics and its response to climate change. This information enables informed decisions to prepare for, and adapt to, climate change in the Yukon River Basin forest. © 2014 by the authors.

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