Future battlegrounds for conservation under global change

Tien Ming Lee Walter Jetz () Receive free email alerts when new articles cite this article - sign up in the box at the top right-hand corner of the article or click here References Email alerting service To subscribe to Proc. R. Soc. B go to: http://rspb.royalsocietypublishing.org/subscriptions Future battlegrounds for conservation under global change Tien Ming Lee and Walter Jetz* Ecology, Behavior and Evolution Section, Division of Biological Sciences, University of California, San Diego, 9500 Gilman Drive MC0116, La Jolla, CA 92093-0116, USA Global biodiversity is under significant threat from the combined effects of human-induced climate and land-use change. Covering 12% of the Earths terrestrial surface, protected areas are crucial for conserving biodiversity and supporting ecological processes beneficial to human well-being, but their selection and design are usually uninformed about future global change. Here, we quantify the exposure of the global reserve network to projected climate and land-use change according to the Millennium Ecosystem Assessment and set these threats in relation to the conservation value and capacity of biogeographic and geopolitical regions. We find that geographical patterns of past human impact on the land cover only poorly predict those of forecasted change, thus revealing the inadequacy of existing global conservation prioritization templates. Projected conservation risk, measured as regional levels of land-cover change in relation to area protected, is the greatest at high latitudes (due to climate change) and tropics/subtropics (due to land-use change). Only some high-latitude nations prone to high conservation risk are also of high conservation value, but their high relative wealth may facilitate additional conservation efforts. In contrast, most lowlatitude nations tend to be of high conservation value, but they often have limited capacity for conservation which may exacerbate the global biodiversity extinction crisis. While our approach will clearly benefit from improved land-cover projections and a thorough understanding of how species range will shift under climate change, our results provide a first global quantitative demonstration of the urgent need to consider future environmental change in reserve-based conservation planning. They further highlight the pressing need for new reserves in target regions and support a much extended northsouth transfer of conservation resources that maximizes biodiversity conservation while mitigating global climate change. 1. INTRODUCTION According to the Millennium Ecosystem Assessment (MA), the greatest threat facing biodiversity is the combined effect of landscape modification due to agricultural development, urbanization and forestry practices, and accelerated climate change (MA 2005). First studies have assessed the patterns and relative immediacy of future environmental change impacts on biodiversity (Sala et al. 2000) and key taxa (e.g. vascular plants, butterflies and birds; Warren et al. 2001; van Vuuren et al. 2006; Jetz et al. 2007), but availability of data has limited scale and generality of results. This may compromise the effective protection of threatened biodiversity and ecosystem services and further exacerbate the current gross disparities between global conservation priorities and funding ( James et al. 1999; Halpern et al. 2006). With approximately 12% of the Earths terrestrial surface formally protected against direct anthropogenic land-cover conversion (Chape et al. 2005), protected areas are crucial for conserving biodiversity and ecosystems, sustaining local livelihoods and supporting natural ecological processes beneficial to human well-being (Balmford et al. 2005; Naughton-Treves et al. 2005). However, current reserves are unlikely to be effective in buffering against Electronic supplementary material is available at http://dx.doi.org/10. 1098/rspb.2007.1732 or via http://journals.royalsociety.org. global climate change impacts as climate and habitat types shift in space. Recent warming has already affected some species geographical or altitudinal ranges with clear consequences for species protection ( Walther et al. 2002; Parmesan & Yohe 2003; Wilson et al. 2005). But to date reserve planning has hardly considered the consequences of rapid climate change on biodiversity protection (but see Williams et al. 2005). This may jeopardize the long-term persistence of species within reserves, particularly those experiencing range shifts (Lovejoy 2005). The effectiveness of the global reserve network in protecting habitats and maintaining representative species diversity has previously been evaluated in relation to past human land-use change (Rodrigues et al. 2004b; Hoekstra et al. 2005). However, whether retrospective evaluations of protected area performance will continue to offer guidance about the future effectiveness of biodiversity protection remains untested. This has serious ramifications for effective long-term conservation planning. Here, we undertake a first global assessment of the impact of future environmental change on the protection of biodiversity. We address the following questions critical to the successful prioritization of future conservation efforts. What is the geography of past and projected environmental change in relation to the existing reserve network? Are patterns of past human land-use change useful indicators of environmental change projected for T. M. Lee & W. Jetz Future global conservation frontlines the future? How do patterns of future conservation risk relate to current-day conservation value to determine conservation need? And how is conservation need distributed across regions worldwide and associated with critical national attributes such as governance and wealth? We base this first assessment on projections of future landcover change, the current-day reserve network and present distribution of terrestrial vertebrates across biomes and nations of the world. This allows us to relate the exposure of current-day biodiversity and its protection to projected change, but it does not address potential shifts in species distribution under climate change, a quandary that is beyond the scope of this study. Potential range shifts near impossible to quantify with full certaintywould modify our specific results, but unlikely overcome the strong patterns of exposure that emerge or invalidate the conceptual connections we develop. We use land-cover projections across four socioeconomic scenarios as provided by the MA. These scenarios are possible futures devised to compare four possible conditions in 2100 ( MA 2005). They use plausible ranges of future greenhouse gas emissions and growth of human populations and economies to estimate the extent to which regions may be affected by anthropogenic climate change and agricultural/urban expansion. Four scenarios were developed that follow two principal development paths, one in which the world (...truncated)