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Efforts to mitigate climate change through the Reduced Emissions from Deforestation and Degradation (REDD) depend on mapping and monitoring of tropical forest carbon stocks and emissions over large geographic areas. With a new integrated use of satellite imaging, airborne light detection and ranging, and field plots, we mapped aboveground carbon stocks and emissions at 0.1-ha resolution over 4.3 million ha of the Peruvian Amazon, an area twice that of all forests in Costa Rica, to reveal the determinants of forest carbon density and to demonstrate the feasibility of mapping carbon emissions for REDD. We discovered previously unknown variation in carbon storage at multiple scales based on geologic substrate and forest type. From 1999 to 2009, emissions from land use totaled 1.1% of the standing carbon throughout the region. Forest degradation, such as from selective logging, increased regional carbon emissions by 47% over deforestation alone, and secondary regrowth provided an 18% offset against total gross emissions. Very high-resolution monitoring reduces uncertainty in carbon emissions for REDD programs while uncovering fundamental environmental controls on forest carbon storage and their interactions with land-use change.

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As the rate and extent of environmental change increases, traditional perspectives on ecosystem management and restoration are being juxtaposed with approaches that focus on the altered settings now being encountered or anticipated. We suggest that a combination of traditional and emerging frameworks is necessary to achieve the multiple goals of ecosystem management, including biodiversity conservation and provision of other ecosystem services such as food and fiber production, recreation, and spiritual enrichment.An effective approach entails a move away from partitioning the environment into dichotomous categories (eg natural/unnatural, production/conservation, intact/degraded). Instead, landscapes are increasingly characterized by a complex mosaic of ecosystems or "patches" in varying states of modification, each of which delivers various combinations of services and presents assorted management challenges and opportunities. These patches interact and affect broader-scale processes (such as water flows and animal migrations), necessitating the urgent development of a conservation and restoration strategy that recognizes these rapid spatial changes.Here, we focus on an emerging framework that differentiates patches according to the degree of change from a historical state (resulting from altered abiotic factors and biotic compositions), the likely extent to which such changes are reversible, and the effect of altered patches on other patches within the landscape (WebPanel 1). This framework, derived from recent research on novel ecosystems (Hobbs et al. 2009, helps to identify the relative values of ecosystems in different conditions and the management options available in each case. As seen from a landscape perspective, this framework provides a comprehensive approach to decision making and management, including much-needed prioritization of resource allocations.n Managing the whole landscape Recent analyses have highlighted the need for management and restoration efforts to go beyond site-focused interventions and to consider landscape and regional scales (Mentz et al. 2013). Ecosystem managers increas- REVIEWS REVIEWS REVIEWSManaging the whole landscape: historical, hybrid, and novel ecosystems The reality confronting ecosystem managers today is one of heterogeneous, rapidly transforming landscapes, particularly in the areas more affected by urban and agricultural development. A landscape management framework that incorporates all systems, across the spectrum of degrees of alteration, provides a fuller set of options for how and when to intervene, uses limited resources more effectively, and increases the chances of achieving management goals. That many ecosystems have departed so substantially from their historical trajectory that they defy conventional restoration is not in dispute. Acknowledging novel ecosystems need not constitute a threat to existing policy and management approaches. Rather, the development of an integrated approach to management interventions can provide options that are in tune with ...

Airborne light detection and ranging (LiDAR) is fast turning the corner from demonstration technology to a key tool for assessing carbon stocks in tropical forests. With its ability to penetrate tropical forest canopies and detect three-dimensional forest structure, LiDAR may prove to be a major component of international strategies to measure and account for carbon emissions from and uptake by tropical forests. To date, however, basic ecological information such as height-diameter allometry and standlevel wood density have not been mechanistically incorporated into methods for mapping forest carbon at regional and global scales. A better incorporation of these structural patterns in forests may reduce the considerable time needed to calibrate airborne data with ground-based forest inventory plots, which presently necessitate exhaustive measurements of tree diameters and heights, as well as tree identifications for wood density estimation. Here, we develop a new approach that can facilitate rapid LiDAR calibration with minimal field data. Throughout four tropical regions (Panama, Peru, Madagascar, and Hawaii), we were able to predict aboveground carbon density estimated in field inventory plots using a single universal LiDAR model (r 2 = 0.80, RMSE = 27.6 Mg C ha -1 ). This model is comparable in predictive power to locally calibrated models, but relies on limited inputs of basal area and wood density information for a given region, rather than on traditional plot inventories. With this approach, we propose to radically decrease the time required to calibrate airborne LiDAR data and thus increase the output of high-resolution carbon maps, supporting tropical forest conservation and climate mitigation policy.