Jonathan M. Hoekstra

Ecological Connectivity for a Changing Climate

A frequently proposed strategy to reduce the negative effects of climate change on biological diversity is to increase ecological connectivity (Heller & Zavaleta 2009)— the flow of organisms and ecological processes across landscapes (Taylor et al. 1993). Traditionally, conservation professionals have sought to maintain or restore connectivity to ensure gene flow among isolated populations and promote recolonization of vacant patches (Hanski 1998). Given the rapid emergence of connectivity enhancement as a climate-change adaptation strategy, we considered whether connectivity should be emphasized in conservation strategies as global or regional temperatures increase and what principles for connectivity enhancement could be applied to maximize the usefulness of the strategy. The best historical analogue for the ongoing rise in global temperatures occurred 55 million years ago at the Paleocene and Eocene boundary, when the average global temperature rose 5–6 ◦C in 10,000–20,000 years (Wing et al. 2005). At that time, species’ ranges shifted and subtropical cypress swamps, complete with alligators, existed on Ellesmere Island in the Arctic (Estes & Hutchison 1980). A similar rise in temperature has been projected within the next 100–200 years (IPCC 2007), two orders of magnitude faster than previous warming events. Movements of some species, however, are now restricted by human-caused fragmentation and other barriers. The primary rationale for increasing connectivity is that if the effects of land-cover fragmentation can be mitigated, this should enhance the ability of species to move into new regions as climate changes (Fig. 1), thereby decreasing the probability of extirpation or extinction. Here, increasing connectivity refers to management actions that facilitate dispersal of species among natural areas, for example, through the establishment of landscape corridors or stepping-stone reserves or through actions that increase matrix permeability. Because funds

Protecting Biodiversity when Money Matters: Maximizing Return on Investment

Background Conventional wisdom identifies biodiversity hotspots as priorities for conservation investment because they capture dense concentrations of species. However, density of species does not necessarily imply conservation ‘efficiency’. Here we explicitly consider conservation efficiency in terms of species protected per dollar invested. Methodology/Principal Findings We apply a dynamic return on investment approach to a global biome and compare it with three alternate priority setting approaches and a random allocation of funding. After twenty years of acquiring habitat, the return on investment approach protects between 32% and 69% more species compared to the other priority setting approaches. To correct for potential inefficiencies of protecting the same species multiple times we account for the complementarity of species, protecting up to three times more distinct vertebrate species than alternate approaches. Conclusions/Significance Incorporating costs in a return on investment framework expands priorities to include areas not traditionally highlighted as priorities based on conventional irreplaceability and vulnerability approaches.

Redesigning biodiversity conservation projects for climate change: examples from the field

Few conservation projects consider climate impacts or have a process for developing adaptation strategies. To advance climate adaptation for biodiversity conservation, we tested a step-by-step approach to developing adaptation strategies with 20 projects from diverse geographies. Project teams assessed likely climate impacts using historical climate data, future climate predictions, expert input, and scientific literature. They then developed adaptation strategies that considered ecosystems and species of concern, project goals, climate impacts, and indicators of progress. Project teams identified 176 likely climate impacts and developed adaptation strategies to address 42 of these impacts. The most common impacts were to habitat quantity or quality, and to hydrologic regimes. Nearly half of expected impacts were temperature-mediated. Twelve projects indicated that the project focus, either focal ecosystems and species or project boundaries, need to change as a result of considering climate impacts. More than half of the adaptation strategies were resistance strategies aimed at preserving the status quo. The rest aimed to make ecosystems and species more resilient in the face of expected changes. All projects altered strategies in some way, either by adding new actions, or by adjusting existing actions. Habitat restoration and enactment of policies and regulations were the most frequently prescribed, though every adaptation strategy required a unique combination of actions. While the effectiveness of these adaptation strategies remains to be evaluated, the application of consistent guidance has yielded important early lessons about how, when, and how often conservation projects may need to be modified to adapt to climate change.

A comparative measure of biodiversity based on species composition

In conservation planning, species richness and species endemism are the most often used metrics for describing the biodiversity importance of areas. However, when it comes to prioritizing regions for conservation actions these measures alone are insufficient because they do not reveal how similar or different the actual composition of species may be from one area to another. For comparative analysis an additional useful metric would be one that indicates the degree to which the species assemblage in one area is also represented in—or is distinct from—species assemblages of other areas. Here we describe a method for quantifying the compositional representativeness of species assemblages among geographic regions. The method generates asymmetric pairwise similarity coefficients that are then used to calculate separate measures for the representativeness and the distinctiveness of species assemblages in the regions being compared. We demonstrate the method by comparing fish communities among freshwater ecoregions of the Mississippi Basin, and then among smaller hydrological units within two individual freshwater ecoregions. At both scales of analysis, our measures of representativeness and distinctiveness reveal patterns of fish species composition that differ from patterns of species richness. This information can enhance conservation planning processes by ensuring that priority-setting explicitly consider the most representative and distinctive species assemblages.

Ecoregions with crop wild relatives are less well protected

Abstract In situ conservation of crop wild relatives (CWR) is recognised as an important factor in maintaining global food security; however, until now there has been no systematic global assessment of the protection status of this vital source of agrobiodiversity. CWR are not spread evenly across the world, but are concentrated in relatively small regions often referred to as ‘centres of food crop diversity’. To assess their global conservation status, we compared levels of habitat protection and habitat loss in centres of crop diversity against global averages for terrestrial ecoregions. Habitat protection in 34 of the worlds 825 ecoregions with the highest levels of agrobiodiversity is significantly lower than the global average - 29 ecoregions had less than 10% protection and six had less than 1% of their area under protection. Some of these ecoregions are also undergoing rapid losses in natural habitat. We outline the importance of protected areas in conserving CWR. In light of the findings, we recommend increased commitments by governments, conservation organizations and the agricultural industry to improve in situ protection of CWR in the worlds centres of crop diversity in order to protect agrobiodiveristy and improve future food security.