Meeting international targets for expanding protected areas could simultaneously contribute to species conservation, but only if the distribution of threatened species informs the future establishment of protected areas.

Sea-level rise (SLR) will greatly alter littoral ecosystems, causing habitat change and loss for coastal species. Habitat loss is widely used as a measurement of the risk of extinction, but because many coastal species are migratory, the impact of habitat loss will depend not only on its extent, but also on where it occurs. Here, we develop a novel graph-theoretic approach to measure the vulnerability of a migratory network to the impact of habitat loss from SLR based on population flow through the network. We show that reductions in population flow far exceed the proportion of habitat lost for 10 long-distance migrant shorebirds using the East Asian-Australasian Flyway. We estimate that SLR will inundate 23-40% of intertidal habitat area along their migration routes, but cause a reduction in population flow of up to 72 per cent across the taxa. This magnifying effect was particularly strong for taxa whose migration routes contain bottlenecks-sites through which a large fraction of the population travels. We develop the bottleneck index, a new network metric that positively correlates with the predicted impacts of habitat loss on overall population flow. Our results indicate that migratory species are at greater risk than previously realized.

Identification of spatial gradients in ecosystem vulnerability to global climate change and local stressors is an important step in the formulation and implementation of appropriate countermeasures 1,2 . Here we build on recent work to map ecoregional exposure to future climate, using an envelopebased gauge of future climate stability-defined as a measure of how similar the future climate of a region will be to the present climate 3,4 . We incorporate an assessment of each ecoregion's adaptive capacity, based on spatial analysis of its natural integrity-the proportion of intact natural vegetationto present a measure of global ecosystem vulnerability. The relationship between intactness (adaptive capacity) and stability (exposure) varies widely across ecoregions, with some of the most vulnerable, according to this measure, located in southern and southeastern Asia, western and central Europe, eastern South America and southern Australia. To ensure the applicability of these findings to conservation, we provide a matrix that highlights the potential implications of this vulnerability assessment for adaptation planning and offers a spatially explicit management guide.Anthropogenic climate change is impacting ecosystems globally, causing changes in phenology, species composition and range shifts 5 , while increasing environmental degradation is leading to habitat fragmentation or loss. These two factors in concert are likely to result in exacerbated biodiversity decline and extinction in the near future 6 . As rates of both biodiversity loss and threats are growing 7 , the identification of spatial gradients of ecosystem vulnerability to both global and regional drivers is required for the development of effective conservation measures.There are three shortcomings in present conservation-oriented climate change assessments, regardless of their spatial scale. The first concerns vulnerability assessments, which until recently have been focused solely on the system's (extrapolated from species') exposure to future climate change, without considering that vulnerability to climate change is influenced by the system's (species') sensitivity and adaptive capacity, as well as exposure 1,2,8,9 . For conservation planning purposes, this sole focus on exposure does not always equate to the identification of areas that have the most pressing needs for adaptation, particularly those that may be relatively stable climatically but are far more vulnerable to climate change owing to other reasons (for example, present levels of vegetation intactness). The second shortcoming is that most climate change assessments have been conducted on species-specific responses, and therefore have been largely unable to inform conservation actions in terms of ecosystem-focused adaptation 10,11 . The third shortcoming