THE YEAR IN ECOLOGY AND CONSERVATION BIOLOGY, 2009 Climate Change Adaptation Strategies for Resource Management and Conservation Planning Joshua J. Lawler College of Forest Resources, University of Washington, Seattle, Washington Recent rapid changes in the Earth’s climate have altered ecological systems around the globe. Global warming has been linked to changes in physiology, phenology, species distributions, interspecific interactions, and disturbance regimes. Projected future cli- mate change will undoubtedly result in even more dramatic shifts in the states of many ecosystems. These shifts will provide one of the largest challenges to natural resource managers and conservation planners. Managing natural resources and ecosystems in the face of uncertain climate requires new approaches. Here, the many adaptation strategies that have been proposed for managing natural systems in a changing climate are reviewed. Most of the recommended approaches are general principles and many are tools that managers are already using. What is new is a turning toward a more agile management perspective. To address climate change, managers will need to act over different spatial and temporal scales. The focus of restoration will need to shift from historic species assemblages to potential future ecosystem services. Active adaptive management based on potential future climate impact scenarios will need to be a part of everyday operations. And triage will likely become a critical option. Although many concepts and tools for addressing climate change have been proposed, key pieces of information are still missing. To successfully manage for climate change, a better un- derstanding will be needed of which species and systems will likely be most affected by climate change, how to preserve and enhance the evolutionary capacity of species, how to implement effective adaptive management in new systems, and perhaps most importantly, in which situations and systems will the general adaptation strategies that have been proposed work and how can they be effectively applied. Key words: adaptation; adaptive management; climate change; conservation planning; management; scenario planning; triage ◦ Introduction jected to rise between 3 and 12 Cbytheendof the century (IPCC 2007b). Precipitation pat- Over the past century, global average annual terns are also projected to change, although temperatures have risen 0.7◦C (IPCC 2007b). the direction, magnitude, and confidence sur- In the Arctic, temperatures have risen at ap- rounding precipitation projections vary by re- proximately twice that rate. This trend is very gion and season. likely to continue into the future, as global aver- These changes have profound implications age surface temperatures are projected to rise for the Earth’s natural systems. Recent climatic between 1.1 and 6.4◦C by 2100, and temper- changes have been linked to decreases in snow- atures at the high northern latitudes are pro- pack (Groisman et al. 2001; Mote 2003), in- creases in the frequency and severity of large wildfires (Westerling et al. 2006), and rising sea levels (IPCC 2007b). These changes in Address for correspondence: Joshua J. Lawler, College of Forest Re- sources, University of Washington, Box 352100, Seattle, WA 98105. turn have the potential to alter the timing and [email protected] magnitude of stream flows, the structure and The Year in Ecology and Conservation Biology, 2009: Ann. N.Y. Acad. Sci. 1162: 79–98 (2009). doi: 10.1111/j.1749-6632.2009.04147.x C 2009 New York Academy of Sciences. 79 80 Annals of the New York Academy of Sciences composition of vegetation communities, and sive species will emerge, and ecosystem func- the nature of coastal systems. As temperatures tions will be altered. and sea levels continue to rise, many ecosys- Plants, corals, and other organisms have tems will undergo significant changes. Coastal clear physiological responses to climate change. wetlands will be inundated, alpine zones will Increased atmospheric CO2 concentrations shrink, and some wetlands, ponds, and lakes can result in increased water-use efficiency in will dry up (IPCC 2007a). plants. Because different species will respond Many ecological systems are already show- differently to increased CO2, differential in- ing the effects of recent climatic changes creased water-use efficiencies will likely result in (Walther et al. 2002; Parmesan and Yohe 2003; shifts in competitive relationships and changes Root et al. 2003; Parmesan 2006). The most in plant communities (Policy et al. 1993). Many well documented changes include changes in corals are extremely sensitive to changes in tem- phenology, species distributions, and physiol- perature. Increases of just a few degrees for even ogy. Recent phenological changes have been a short period can result in bleaching (a loss of observed in many different ecological systems the coral’s symbiotic zooxanthellae and their (Sparks and Carey 1995). Spring events, for ex- photosynthetic pigments). Extensive bleaching ample, have been occurring 2.3 days earlier events have occurred during the past 20 years per decade over the last century (Parmesan in several regions around the globe (West and and Yohe 2003). Plants are flowering and fruit- Salm 2003). Several species of fish also have ing earlier (Cayan 2001), birds are laying eggs well-documented thermal thresholds for sur- earlier (Brown et al. 1999; Crick and Sparks vival at different life stages (e.g., McCullough 1999), and some amphibians are mating ear- 1999; Moyle 2002). Even small changes in tem- lier (Beebee 1995; Gibbs and Breisch 2001). perature have the potential to affect population Changes in phenology have the potential to dynamics and habitat use for many species. decouple interdependent ecological events, re- Managing natural systems in the face of such sulting in changes in species interactions, com- widespread change is a daunting task. Perhaps munity composition, and ecosystem function- the largest challenge for mangers is making de- ing (Stenseth and Mysterud 2002). cisions based on limited and often highly un- The paleoecological record indicates that certain projections of future climate impacts species have shifted their geographic ranges (Lawler et al. in press-b). Over the past 10 to in the past in response to changes in climate 20 years, researchers have begun to suggest (Brubaker 1989; Davis and Shaw 2001). More ways that managers and planners can begin recent records indicate that species have also to address climate change. Here, I summa- shifted their distributions in response to re- rize these recommendations. I begin with an cent climate change. Many species of plants, overview of the general, largely conceptual, rec- birds, butterflies, and amphibians have shifted ommended adaptation strategies. I go on to their distributions in patterns and at rates that describe some of the more specific suggestions are consistent with recent climatic changes that have been made for addressing climate (Parmesan 2006). In general, these species are change in freshwater, marine, and terrestrial shifting their ranges upward in elevation and systems. Although many of the recommended poleward in latitude (Parmesan et al. 1999; approaches for addressing climate change are Thomas and Lennon 1999; Seimon et al. 2007; already used to manage resources and protect Lenoir et al. 2008). In a few cases, popula- biodiversity, effectively implementing these ap- tion and even species extinctions have been at- proaches will require new perspectives. I con- tributed to recent climatic changes (Pounds et al. clude with a brief discussion of the most press- 1999). As species move in response to climate ing research needs for successfully developing change, new communities will form, new inva- and implementing adaptation strategies. Lawler: Climate Change Adaptation Strategies 81 General Strategies for Addressing toxicity of pesticides or the infection rates and Climate Change severity of diseases (Kumaraguru and Beamish 1981). Likewise climate change may increase The vast majority of the proposed strategies competitive pressure from invasive species, as for managing resources in a changing climate some invasive species may benefit from in- are general concepts. These concepts can be creased atmospheric CO2 concentrations or loosely grouped into three basic types of strate- changes in temperature or precipitation, allow- gies: those promoting resistance, resilience, and ing them to spread and/or outcompete native change (Millar et al. 2007). Resistance is the abil- species (Dukes and Mooney 1999; Schlesinger ity of a system to remain unchanged in the face et al. 2001; Zavaleta and Royval 2001; Rahel of external forces. Resilience can be defined as and Olden 2008). the ability of a system to recover from pertur- Environmental stresses may also reduce bations (Holling 1973). A resilient system will the resilience of individuals and populations change in response to external forces but will to climate change. For example, Drosophila return to its original state. With respect to cli- melanogaster exposed to parasitic attacks while mate change, systems that are more resilient are in the larval stage were more susceptible to those that are better able to adapt to changes desiccation that those not exposed to para- in climate. Resilient systems will continue to sitic attacks (Hoang 2001). Similarly,streamside function, albeit potentially differently, in an al- salamanders, Ambystoma barbouri, exposed to the tered climate. Less resilient systems will