Climate-Wise Connectivity: How to Plan and Implement

Symposium
ROOM: Room 235 – Mesilla
SESSION NUMBER: 45
 
While the field of connectivity conservation is now several decades old, increasing landscape connectivity specifically to facilitate range shifts of wildlife and their habitats in response to climate change has recently emerged as a high priority for biodiversity conservation. Climate-wise connectivity plans must not only consider where species are moving and their original ranges, but also accommodate future species distributions and be designed to function for several decades. The purpose of this symposium is to explore how planning and implementing connectivity with the specific goal of facilitating range shifts can be and is being accomplished and outline associated challenges. Numerous modeling approaches integrating connectivity and climate change science have been developed for local to continental scales. They are planning structural or functional connectivity, connecting current to future ranges, lowland areas to mountains, climate analogs, or protected areas. Presentations will cover the theoretical aspects of climate-wise connectivity modeling and, through case-studies, will illustrate how the concepts of climate-wise connectivity can be realized on the ground. Planning and implementation projects described span multiple objectives, including to: 1) prioritize climate-wise connectivity conservation actions, 2) propose solutions to establishing climate connectivity while controlling the spread of invasive species, 3) examine climate connectivity for dispersal-limited butterflies in an agricultural landscape, 4) design connectivity to facilitate the range shift of a small mammal, and 5) illustrate a habitat restoration project designed to connect two mountain ranges.

1:10PM What Is Climate-Wise Connectivity?
  Paul Beier
Improving connectivity is the most-frequently recommended strategy for helping biodiversity cope with climate change. Climate-wise connectivity must allow species to shift their range. But how do we prioritize land to do this? Once suitable corridors or steppingstones or working landscapes are prioritized, is restoration or special management required? In this symposium, we describe the full spectrum of strategies for climate wise connectivity. At the low-tech end, we can prioritize riparian corridors. Because riparian areas are natural travel routes for many plants and animals, will remain the wettest parts of the landscape in any climate, often follow climate gradients, and (if wide enough) incorporate diverse climates and abiotic settings, they should be part of any climate-connectivity plan. The papers in this symposium will outline the more sophisticated complements to riparian corridors, which I will introduce briefly. These strategies include land facet corridors, climate gradient corridors, climate diversity corridors, mobile reserves, assisted colonization, and modeling the shift climate space of individual species. As with conventional corridors, the issue of minimum corridor width is a crucial unresolved issue.
1:30PM Integrating Connectivity and Climate Change Science to Model Connectivity – a Systematic Review
  Annika Keeley; Adina Merenlender; Patrick Huber
Abstract: While habitat connectivity research is several decades old, prioritizing landscape connectivity to facilitate range shifts in response to climate change is a new conservation challenge. We systematically reviewed the literature on modeling approaches that integrate connectivity and climate change science to analyze the emerging solutions. We identified 67 original studies and 31 essays and reviews published between 2003 and 2017. About 2/3 of the original studies (N=43) modeled connectivity yielding linear corridors, permeability rasters with prioritized grid cells, or habitat networks. The other 1/3 of the studies (N=24) assessed connectivity either with detailed population simulations, or based on empirical data. Objectives of the connectivity modeling studies included linking climate analogs, climate-based species distribution models, geomorphic features such as land facets, or riparian areas. Spatial models incorporated factors such as human land use, degree of naturalness, environmental gradients, climate velocity, current and future habitat suitability, dispersal ability and climatic hold-outs. To detect major pathways along which species ranges will shift in response to climate change, some studies (N=11) modeled current and predicted ranges of hundreds of species based on climatic preferences. Others avoided species specific approaches and/or future climate predictions to reduce uncertainty, but relied on geomorphic features, environmental gradients, or naturalness alone (N=17). With only 6 papers using more than one method, little information is available to compare the effect of different methods on linkage delineation and prioritization. To assess connectivity under climate change, studies investigated factors that influence species’ abilities to shift their ranges with climate change including climate velocity, dispersal ability, degree of landscape fragmentation, configuration of the landscape, and population size at the leading edge of the range. We will discuss advantages and disadvantages of existing approaches for integrating connectivity and climate science and summarize conclusions of studies assessing connectivity under climate change.
1:50PM Linking Landscapes and Climates: Two Approaches to Modeling Connectivity for Climate Change
  Joshua J. Lawler; Caitlin E. Littlefield; Julia Michalak; Jenny McGuire; Brad H. McRae
Improving connectivity is one of the most often recommended adaptation strategies for conserving biodiversity in a changing climate. However, it is not clear whether connecting today’s habitats for today’s species will provide the connectivity that is needed in the future. Here, we demonstrate two approaches to planning for connectivity that would potentially allow species to move in response to climate change. The first approach involves connecting patches of more intact natural landscapes with routes that allow species to move across existing climate gradients while avoiding barriers to movement. We have applied this first approach at a national scale, both to identify priority areas for conservation and to explore the degree to which species will be able to track current temperatures into the future. The second approach draws on the concept of climatic refugia and tracks shifts in climate—linking today’s climates with the locations of their future analogues. To explore how climate change will shift spatial priorities for connectivity planning, we compared the areas identified by this approach to areas highlighted by a similar analysis that focused only on connecting more intact portions of the landscape.
2:10PM Adapting Connectivity Conservation to Climate Change: A Case Study from the Pacific Northwest
  Meade Krosby
Species have historically used movement to adapt to changes in climate, shifting their ranges across landscapes to stay within climatically suitable habitat. For this reason, enhancing habitat connectivity is a leading strategy for helping wildlife respond to climate change. And yet, significant challenges remain in translating this high-level strategy into specific, on-the-ground actions. The Washington-British Columbia Transboundary Climate-Connectivity Project was initiated to help address these challenges. This project paired scientists and practitioners from both sides of the border to collaboratively identify potential climate impacts and adaptation actions for transboundary habitat connectivity, using a diverse suite of case study species, a vegetation system, and a region. Because a key project goal was to increase practitioner partners’ capacity to access, interpret, and apply existing climate and connectivity model outputs to their decision-making, participants relied on a few primary datasets that are freely available and span all or part of the transboundary region. Case study assessments revealed that climate change is likely to have significant implications for transboundary habitat connectivity. The adaptation actions identified to address potential impacts varied by case study, but fell into two general categories: those addressing potential climate impacts on existing habitat connectivity and those addressing novel habitat connectivity needs for climate-induced shifts in species ranges. In addition, project partners identified priority spatial locations for implementing these actions, as well as additional research needed to improve assessment of climate impacts and adaptation actions for habitat connectivity. The project resulted in a suite of products designed in collaboration with project partners to ensure their relevance and ease of application to decision-making. In addition, project participants emerged with enhanced capacity and a transboundary community of practice for addressing climate change and habitat connectivity in their decision-making.
2:30PM Prioritizing Corridors and Protected Area Expansions to Facilitate Species Range Shifts in Sonoma County, California
  Morgan Gray; Adina M. Merenlender
Maintaining and improving habitat connectivity through the conservation of habitat corridors is the most frequently referenced tactic for increasing resilience of reserve networks to climate change. On the ground this involves local efforts to prioritize corridors across modified landscapes at the land parcel scale. To evaluate the extent that corridors, commonly implemented by local conservation efforts to connect fragmented regional landscapes, provide increased resilience to climate change, we examined the landscape permeability and climate benefit across the Sonoma Valley Wildlife Corridor (SVWC) in Sonoma County, California. The SVWC is a critical linkage connecting Sonoma Mountain on the coast with the inland Mayacamas Range, and is highly threatened by residential and agricultural development. We quantified the potential for the SVWC to allow for wildlife movement using landscape permeability to identify the least developed areas that may facilitate wildlife movement across the linkage. The distribution and representation of climate space was examined using bias-corrected downscaled climate models to evaluate different characteristics of climate based on three distinct assumptions for improving reserve network resilience to climate change: 1) access to cooler climates; 2) maintaining continuous habitat across a diversity of climate types; and 3) maintaining access to areas with slower rates of change. We found that the SVWC has high potential for landscape permeability that would allow for free passage of wildlife if left undisturbed, and represents one of the only options for wildlife movement across the valley between the adjacent mountain ranges. Maintaining this corridor may be essential for some species in the region to adapt to climate change by shifting their distribution to cooler locations. The larger connected habitat patch that would result from conserving the Sonoma Valley Wildlife Corridor will also provide a greater overall diversity of climate types, which should be valuable for species adaptation in the future.
2:50PM Refreshment Break
3:20PM Nested Connectivity Models to Resolve Management Conflicts and Promote Climate Change Resilience Using Mule Deer and American Bullfrogs in the Sonoran Desert as Study System
  Joseph Drake; Nancy McIntyre; Kerry Griffis-Kyle
Climate change is altering connectivity of surface water for organisms, especially in arid systems. Connectivity of these resources is essential for organisms to disperse, find mates, access resources, and shift ranges in response to changing climatic conditions. Management conflicts can arise if attempts to maintain or enhance connectivity result in opening up dispersal corridors to invasive species and disease vectors to already-threatened native species. Using the mule deer (Odocoileus hemionus) and American bullfrog (Lithobates catesbeianus) as examples in a network of surface waters in the Sonoran Desert, we illustrate and propose a resolution to these conflicts. Structural and functional metrics from least-cost path analyses, graph theory, and circuit theory can be used to quantify landscape connectivity within a spatially nested framework under current and future climate-based scenarios at regional and local scales. Results indicated that climate change is likely to reduce structural and functional connectivity for these species. We demonstrate how to use this method to select sites for new water developments that promote the connectivity of habitat for the native, economically important mule deer, while fragmenting the network in key locations to halt the progress of the invasive American bullfrog. Understanding both local and regional connectivity may make the difference in solving local management conflicts and promoting regional climate change adaptability.
3:40PM Dispersal Limitation, Climate Change, and Practical Tools for Conservation in Intensively Used Landscapes
  Laura Coristine
Many species are susceptible to changing thermal regimes associated with recent climate change. While species and populations are responding to climate changes in various ways, there are indications that many species are not keeping pace. Rapid climate changes are leading to an accumulation of climate debts (or loss of climatic habitat) at continental scales. Climate change mediated shifts in distribution depend on factors such as, species-specific dispersal abilities and habitat availability. Using butterfly species as an example, we measured geographical variation in mobility across North America relative to conservation status and the intensity of human land use. We identified areas where the rate and variability of recent climatic changes have been relatively low and could be managed for conservation, potentially augmenting existing protected area networks. Using the Yellowstone to Yukon region as a case study, we outline differences between connectivity analyses that incorporate (i) human footprint, (ii) human footprint in conjunction with climate change considerations, and (iii) human footprint in conjunction with climate change considerations weighted by species mobility and richness. All three approaches yield different connectivity recommendations. Conservation management efforts to enhance climate change-related dispersal should focus on improving landscape connectivity based on species-specific mobility, richness, and climate change, as well as landscape permeability. Improving connectivity is particularly vital in areas where mobility and landscape permeability are low but species are at greatest risk of extinction.
4:00PM Multi-Scale Connectivity Approaches As a Means of Implementing Climate-Wise Connectivity Planning for the Mohave Ground Squirrel
  Thomas E. Dilts; Peter J. Weisberg; Marjorie D. Matocq; Kevin Shoemaker; Miranda Crowell; Eveline Larrucea; Kenneth Nussear; Phillip Leitner; Richard Inman; Todd Esque
Conservation planning requires synthesizing information at multiple spatial scales and accounting for the interaction between a changing climate and anthropogenic impacts. We illustrate a multi-scale approach that uses graph theory, circuit theory, and least-cost analysis to predict potential changes in both habitat amount and habitat connectivity for the Mohave ground squirrel, a California threatened species whose habitat overlaps with proposed placement of utility-scale renewable energy development. Our results highlight how potential impacts can be compared across both climate change and energy development scenarios at the range-wide scale and how habitat connectivity losses (and gains) can be evaluated relative to changes in habitat area. At the regional scale we used graph theory to identify critical conservation areas, such as core areas and stepping stones, which can be integrated into landscape-level conservation planning. At the local scale we use circuit theory to delineate finer-scale pinch points that may impede movement in critical portions of the range, including areas where range expansion is predicted to occur for the species to track its climate niche. Finally, we discuss ongoing habitat connectivity modeling work on the pygmy rabbit, a sagebrush obligate species that has experienced population declines in recent years. Our approach integrates information at three spatial scales, is useful for simultaneously assessing the impacts of both climate change and land cover change, and is applicable to both patchily and continuously-distributed habitat.
4:20PM Climate-wise Connectivity on the Kenai Peninsula, Alaska
  Tracy A. Melvin
Climate connectivity has tended to focus on maintaining or enhancing landscapes in the context of facilitating animal and plant movements into novel areas as temperature and precipitation regimes shift. It has since progressed into advances in linkages, preventing chokepoints, maintaining permeable working landscapes, and minimizing the rate of climate change species will experience as ranges contract and expand. There are instances, however, when facilitating corridors of movement should be reevaluated for potential effects on biodiversity, endemism, and forest health. This may be the case on for the 2 million-acre Kenai National Wildlife Refuge, which has undergone changes to ecosystem function from climate change, and is a leading case study in the National Fish, Wildlife and Plants Climate Adaptation Strategy (2012). Alaska has warmed 2X faster than the continental United States during the last 50 years, resulting in wetland loss, warming soils, reduced soil water, and emergence of novel ecosystems including the conversion of spruce forests to grassland savanna. Warmer temperatures have boosted populations of spruce bark beetle, enabling the native pest to devastate four million acres of forest on the peninsula and south-central Alaska over a 15-year period. Climate envelope modeling portrays a future landscape of converted alpine tundra to forest, to hardwood forests and catastrophic deforestation in the south. The Kenai Peninsula is a unique case study for climate adaptation in that it has geographical features that influence ecological trajectories, such as the 1800-m-high Kenai Mountains and 16 km isthmus that connects the peninsula to mainland Alaska acting as a both a bottleneck for climate-driven migration and conduit for introduced invasive and exotic plant species. Stewarding future landscapes on the Kenai Peninsula requires thoughtful consideration of climate-wise connectivity. Here I discuss endemism, exotic species transmissions, and current considerations of forest health in a rapidly changing environment.

 
Organizers: Annika Keeley, University of California, Berkeley, CA; Angela Larsen, University of North Carolina, Greensboro, NC; Matthew Ihnken, University of Michigan, Flint, MI; Suzie Prange, Ohio Department of Natural Resources, Athens, OH; Mary Rowland, US Forest Service, Pacific Northwest Research Station, La Grande, OR; Jan Schipper, Arizona Center for Nature Conservation/Phoenix Zoo, Phoenix, AZ; Laura Thompson, USGS National Climate Change and Wildlife Science Center, Reston, VA
 
Supported by: TWS Climate Change and Wildlife Working Group, TWS Forestry and Wildlife Working Group, TWS Biological Diversity Working Group, TWS Wildlife and Habitat Restoration Working Group

Symposium
Location: Albuquerque Convention Center Date: September 25, 2017 Time: 1:10 pm - 5:00 pm