Journal articleIFPRI3; ISI; CRP2; CRP5; E Building ResilienceEPTD; PIMPRCGIAR Research Program on Policies, Institutions, and Markets (PIM); CGIAR Research Program on Water, Land and Ecosystems (WLE

The magnitude and pace of global change demand rapid assessment of nature and its contributions to people. We present a fine-scale global modeling of current status and future scenarios for several contributions: water quality regulation, coastal risk reduction, and crop pollination. We find that where people’s needs for nature are now greatest, nature’s ability to meet those needs is declining. Up to 5 billion people face higher water pollution and insufficient pollination for nutrition under future scenarios of land use and climate change, particularly in Africa and South Asia. Hundreds of millions of people face heightened coastal risk across Africa, Eurasia, and the Americas. Continued loss of nature poses severe threats, yet these can be reduced 3- to 10-fold under a sustainable development scenario.

21There is a growing pressure of human activities on natural habitats, which leads to 22 biodiversity losses. To mitigate the impact of human activities, environmental policies are 23 developed and implemented, but their effects are commonly not well understood because 24 of the lack of tools to predict the effects of conservation policies on habitat quality and/or 25 diversity. We present a straightforward model for the simultaneous assessment of terrestrial 26and aquatic habitat quality in river basins as a function of land use and anthropogenic 27 threats to habitat that could be applied under different management scenarios to help 28 understand the trade-offs of conservation actions. We modify the InVEST model for the 29 assessment of terrestrial habitat quality and extend it to freshwater habitats. We assess the 30 model reliability in a severely impaired basin by comparing modeled results to observed 31 terrestrial and aquatic biodiversity data. We believe that the developed model can be useful to assess potential levels of 37 biodiversity, and to support conservation planning given its capacity to forecast the effects 38 of management actions in river basins. 39 40 Keywords: anthropogenic threats; biodiversity; environmental management; habitat quality; 41 scenario analysis; river basin. 42 43 3

The agricultural expansion and intensification required to meet growing food and agri-based product demand present important challenges to future levels and management of biodiversity and ecosystem services. Influential actors such as corporations, governments, and multilateral organizations have made commitments to meeting future agricultural demand sustainably and preserving critical ecosystems. Current approaches to predicting the impacts of agricultural expansion involve calculation of total land conversion and assessment of the impacts on biodiversity or ecosystem services on a per-area basis, generally assuming a linear relationship between impact and land area. However, the impacts of continuing land development are often not linear and can vary considerably with spatial configuration. We demonstrate what could be gained by spatially explicit analysis of agricultural expansion at a large scale compared with the simple measure of total area converted, with a focus on the impacts on biodiversity and carbon storage. Using simple modeling approaches for two regions of Brazil, we find that for the same amount of land conversion, the declines in biodiversity and carbon storage can vary two-to fourfold depending on the spatial pattern of conversion. Impacts increase most rapidly in the earliest stages of agricultural expansion and are more pronounced in scenarios where conversion occurs in forest interiors compared with expansion into forests from their edges. This study reveals the importance of spatially explicit information in the assessment of land-use change impacts and for future land management and conservation.ecosystem services | deforestation | agricultural expansion | fragmentation | edge effects

Carbon stock estimates based on land cover type are critical for informing climate change assessment and landscape management, but field and theoretical evidence indicates that forest fragmentation reduces the amount of carbon stored at forest edges. Here, using remotely sensed pantropical biomass and land cover data sets, we estimate that biomass within the first 500 m of the forest edge is on average 25% lower than in forest interiors and that reductions of 10% extend to 1.5 km from the forest edge. These findings suggest that IPCC Tier 1 methods overestimate carbon stocks in tropical forests by nearly 10%. Proper accounting for degradation at forest edges will inform better landscape and forest management and policies, as well as the assessment of carbon stocks at landscape and national levels.