Lee Hannah

Climate change, wine, and conservation

Climate change is expected to impact ecosystems directly, such as through shifting climatic controls on species ranges, and indirectly, for example through changes in human land use that may result in habitat loss. Shifting patterns of agricultural production in response to climate change have received little attention as a potential impact pathway for ecosystems. Wine grape production provides a good test case for measuring indirect impacts mediated by changes in agriculture, because viticulture is sensitive to climate and is concentrated in Mediterranean climate regions that are global biodiversity hotspots. Here we demonstrate that, on a global scale, the impacts of climate change on viticultural suitability are substantial, leading to possible conservation conflicts in land use and freshwater ecosystems. Area suitable for viticulture decreases 25% to 73% in major wine producing regions by 2050 in the higher RCP 8.5 concentration pathway and 19% to 62% in the lower RCP 4.5. Climate change may cause establishment of vineyards at higher elevations that will increase impacts on upland ecosystems and may lead to conversion of natural vegetation as production shifts to higher latitudes in areas such as western North America. Attempts to maintain wine grape productivity and quality in the face of warming may be associated with increased water use for irrigation and to cool grapes through misting or sprinkling, creating potential for freshwater conservation impacts. Agricultural adaptation and conservation efforts are needed that anticipate these multiple possible indirect effects.

Climate Change, Connectivity, and Conservation Success

Ten years ago in the pages of Conservation Biology, Whitten et al. (2001) asked whether writing about conservation biology served as displacement behavior for biologists. Their point was that extensive destruction of forests in Southeast Asia coincided with a surge in publications about conservation in the region (Whitten et al. 2001). Were biologists writing papers because they had lost the real conservation battle? The same question applies today to climate change. Is studying climate-change biology a kind of displacement behavior for conservation professionals? Is our professional community writing so much about climate change because we have been impotent in addressing habitat loss, the real alpha male of modern conservation? It is a challenge to address future threats without allowing them to distract all attention from current action. Although each of us needs to reflect on our motivations and effectiveness, the scientific basis for action can be more objectively evaluated. Scientists have been exploring climate-change biology for approximately the same amount of time that Conservation Biology has been published. The seminal papers of Peters and others (e.g., Peters & Darling 1985) appeared as this journal was gaining prominence, and soon articles from these authors appeared in these pages. It now can be asked whether the 25 years of literature provides a sound foundation to inform action. Here the case will be made that conservation professionals now have the necessary knowledge to address climate change and habitat loss in an integrated way. Action needs to be taken quickly to avoid the threshold at which habitat loss forecloses our options to address climate change. Rapid, informed action and clear priorities can ensure that climate-change biology provides for endurance of our immediate conservation gains and is not an outlet for displacement behavior. Action in Response to Climate Change

Global Climate Change Adaptation Priorities for Biodiversity and Food Security

International policy is placing increasing emphasis on adaptation to climate change, including the allocation of new funds to assist adaptation efforts. Climate change adaptation funding may be most effective where it meets integrated goals, but global geographic priorities based on multiple development and ecological criteria are not well characterized. Here we show that human and natural adaptation needs related to maintaining agricultural productivity and ecosystem integrity intersect in ten major areas globally, providing a coherent set of international priorities for adaptation funding. An additional seven regional areas are identified as worthy of additional study. The priority areas are locations where changes in crop suitability affecting impoverished farmers intersect with changes in ranges of restricted-range species. Agreement among multiple climate models and emissions scenarios suggests that these priorities are robust. Adaptation funding directed to these areas could simultaneously address multiple international policy goals, including poverty reduction, protecting agricultural production and safeguarding ecosystem services.

Lessons from Finance for New Land-Conservation Strategies Given Climate-Change Uncertainty

Economists have developed decision-making strategies to deal with uncertainty in financial and commercial markets. Conservation professionals can use some of these strategies to increase the probability of achieving their objectives given increases in outcome uncertainty due to climate change. Protected areas designed to conserve multiple species are usually selected on the basis of current habitat quality for different species (Pressey et al. 2007) and economic factors (Costello & Polasky 2004). The most common mechanisms for designating protected areas are government decree, private purchase, and permanent easements. This deterministic conservation paradigm may not work well, however, under climate uncertainty. Scientists are considering how climate change may affect conservation outcomes (Heller & Zavaleta 2009; Mawdsley et al. 2009). Nevertheless, projections of such outcomes are uncertain because many factors that affect the value of land for conservation, such as species locations, stream flows, and disturbance regimes, will be altered by climate change. Scientists have proposed strategies to protect species as climate changes, including increasing protected-area connectivity (Williams et al. 2005), expanding reserves in areas in which both current and future climate are likely to be suitable for target species (Hannah et al. 2007), and protecting landscape diversity (e.g., Hodgson et al. 2009; Beier & Brost 2010). None of these strategies, however, evade the difficulties of decision making under uncertainty; one cannot have perfect foresight of which lands will in the future be the most effective investments for conserving species. Making optimal use of short-term conservation contracts to preserve options and use of portfolios

Climate change influences on pollinator, forest, and farm interactions across a climate gradient

Climate impact models are often implemented at horizontal resolutions (“scales”) too coarse to be readily applied in local impact assessments. However, recent advancements in fine-scale modeling are allowing the creation of impact models that can be applied to landscape-scale adaptation planning. Here, we illustrate the use of fine-scale impact models for landscape-scale adaptation planning of pollination services for six sites in Central America. The strategies include the identification of (1) potential reservoir areas that may retain bee diversity and serve as a source of recolonization after climate shocks such as droughts; and (2) potential restoration areas, where improving forest cover is likely to lead to increases in pollinator services both in the present and in the future. Coarse-scale (>1-km horizontal resolution) climatic controls on pollinator diversity and forest cover determine the general location of these areas in our six landscapes. Fine-scale (<100-m horizontal resolution) variation in climatic water deficit provides an index of forest health which can help identify intervention strategies within these zones. All sites have significant areas in which protecting or restoring forest cover is likely to enhance pollination services. The gradient in rainfall change across the study sites dictates choice of adaptation strategies.

Conservation Planning for Offsetting the Impacts of Development: A Case Study of Biodiversity and Renewable Energy in the Mojave Desert

Balancing society’s competing needs of development and conservation requires careful consideration of tradeoffs. Renewable energy development and biodiversity conservation are often considered beneficial environmental goals. The direct footprint and disturbance of renewable energy, however, can displace species’ habitat and negatively impact populations and natural communities if sited without ecological consideration. Offsets have emerged as a potentially useful tool to mitigate residual impacts after trying to avoid, minimize, or restore affected sites. Yet the problem of efficiently designing a set of offset sites becomes increasingly complex where many species or many sites are involved. Spatial conservation prioritization tools are designed to handle this problem, but have seen little application to offset siting and analysis. To address this need we designed an offset siting support tool for the Desert Renewable Energy Conservation Plan (DRECP) of California, and present a case study of hypothetical impacts from solar development in the Western Mojave subsection. We compare two offset scenarios designed to mitigate a hypothetical 15,331 ha derived from proposed utility-scale solar energy development (USSED) projects. The first scenario prioritizes offsets based precisely on impacted features, while the second scenario offsets impacts to maximize biodiversity conservation gains in the region. The two methods only agree on 28% of their prioritized sites and differ in meeting species-specific offset goals. Differences between the two scenarios highlight the importance of clearly specifying choices and priorities for offset siting and mitigation in general. Similarly, the effects of background climate and land use change may lessen the durability or effectiveness of offsets if not considered. Our offset siting support tool was designed specifically for the DRECP area, but with minor code modification could work well in other offset analyses, and could provide continuing support for a potentially innovative mitigation solution to environmental impacts.

Predicted impacts of climate warming on aerobic performance and upper thermal tolerance of six tropical freshwater fishes spanning three continents

Abstract Equatorial fishes, and the critically important fisheries based on them, are thought to be at-risk from climate warming because the fishes have evolved in a relatively aseasonal environment and possess narrow thermal tolerance windows that are close to upper thermal limits. We assessed survival, growth, aerobic performance and critical thermal maxima (CTmax) following acute and 21 d exposures to temperatures up to 4°C higher than current maxima for six species of freshwater fishes indigenous to tropical countries and of importance for human consumption. All six species showed 1.3–1.7°C increases in CTmax with a 4°C rise in acclimation temperature, values which match up well with fishes from other climatic regions, and five species had survival >87% at all temperatures over the treatment period. Specific growth rates varied among and within each species in response to temperature treatments. For all species, the response of resting metabolic rate (RMR) was consistently more dynamic than for maximum metabolic rate, but in general both acute temperature exposure and thermal acclimation had only modest effects on aerobic scope (AS). However, RMR increased after warm acclimation in 5 of 6 species, suggesting incomplete metabolic compensation. Taken in total, our results show that each species had some ability to perform at temperatures up to 4°C above current maxima, yet also displayed certain areas of concern for their long-term welfare. We therefore suggest caution against the overly broad generalization that all tropical freshwater fish species will face severe challenges from warming temperatures in the coming decades and that future vulnerability assessments should integrate multiple performance metrics as opposed to relying on a single response metric. Given the societal significance of inland fisheries in many parts of the tropics, our results clearly demonstrate the need for more species-specific studies of adaptive capacity to climate change-related challenges.