Wildlife Connectivity for Dynamic Landscapes (hosted by TWS)

Habitat fragmentation and degradation are two of the greatest threats to habitat availability and quality, posing a direct risk to species’ persistence and consequently, to biodiversity. As anthropogenic features alter the landscape, connectivity for wildlife may be reduced. Establishing or preserving functional landscape connectivity allows for movement and gene flow among populations, increasing the likelihood of population persistence in such fragmented environments. Further, connectivity can support recovery of populations after events such as fire and disease outbreaks. Traditionally, landscape connectivity modeling has relied on methods that assume a static environment. In recent years, more research has focused on capturing the true dynamic nature of landscapes and wildlife movement for connectivity planning. This symposium will explore some of the advances that have been made in modeling and conservation approaches reflecting environmental variability related to extreme events, climate change, as well as land-use shifts and expanding urbanization.

1:10PM Building Landscape Resilience through Climate Connectivity
  Morgan Gray
Connectivity between natural areas is crucial to mitigate climate change effects on biodiversity across human-modified landscapes. Conservation practitioners rely on high-resolution data and local knowledge to prioritize and secure linkages that offer connectivity benefits today and under future climate scenarios. Identifying locations that enhance year-round climate connectivity is particularly important in species-rich and topographically-diverse areas like Mediterranean landscapes. However, climate connectivity is often evaluated using average temperature data as input, which fails to capture seasonal temperature extremes. To evaluate climate connectivity across a human-modified and topographically-diverse landscape, we constructed linkages between protected lands in California and compared their climate benefit under future scenarios using summer, winter, and average temperature. We generated linkages using high-resolution landscape and climate models, and conducted parcel-scale assessments to inform local implementation. Land managers advised on analytical framework and reviewed model predictions through ongoing, iterative engagement. Our results showed disparate spatial trends and climate benefit predictions for seasonal temperatures not apparent in the average temperature analyses. Average temperature forecasts under-predicted locations of seasonal warming by mid-century, with cooler summer temperatures coastward and cooler winter temperatures inland and upslope. Cooling linkages also differed by season; linkages offering the greatest climate benefit connected interior lands access to coastal habitat in summer, and lowland areas access to high-elevation areas in winter. Climate forecasts that include seasonal temperature extremes can improve connectivity planning in topographically-diverse landscapes by identifying specific linkages that can meet the climate needs of wildlife year-round. Collaborating with land managers allowed us to refine project design, ground-truth model outputs, and create data products that facilitate parcel-scale conservation action (e.g., acquisition, restoration). Our approach provides a template for building social and physical landscape linkage networks to advance regional climate connectivity implementation across multiple jurisdictions, land ownership types, and management goals.
1:30PM Connectivity Planning Under Uncertainty: A Scenario-Based Approach to Climate Connectivity
  Megan Jennings, Erin Conlisk, Emily Haeuser, Rebecca Lewison
Habitat connectivity is essential to climate-smart landscape strategies and strengthens ecosystem resilience to additional stressors such as habitat fragmentation, and disturbance. Connectivity allows for wildlife movement among patches of suitable habitat, reduces the risk of extinction for small populations, and maintains gene flow in patchy landscapes. In coastal southern California, connected conservation networks have been established over the last 25 years to protect natural communities and prevent further habitat fragmentation that would threaten long-term ecosystem viability and persistence. Despite this conservation history, implementation of climate-smart connectivity through reserve design, acquisition, and restoration has lagged. To facilitate decision making under uncertainty, we developed a scenario-based focal species approach to model, assess, and prioritize landscape linkages. For this assessment, we used a novel complement of ensemble species distribution models and connectivity models linked with dynamic metapopulation models to advance connectivity planning accounting for climate change, land-use shifts, and uncertainty. We applied these methods to each species for four climate scenarios and prioritized landscape linkages across the region to assemble a single, multispecies linkage network. The prioritization included not only a climate consensus value from the scenarios and biological importance derived from the metapopulation models, but also incorporated connectivity and habitat metrics as well as feasibility considerations. Once linkages were prioritized for each species, those with highest values were selected for inclusion in the multispecies network. Finally, land facet or landform linkages were modeled and those static landscape features that were not already represented were integrated into the network. This methodology provides a robust approach to adaptive planning and conservation decision- making under uncertainty. By combining climate considerations with connectivity and landscape metrics, this framework can support efforts to preserve biodiversity and proactive planning to help keep common species common under climate change.
1:50PM Modeling Habitat Connectivity to Enable Adaptation to Climate Change Impacts in California
  Dick Cameron, Carrie Schloss, Dave Theobald
Changes in climate have already driven shifts in distribution for some plants and animals. Managing protected areas in the face of accelerating and unpredictable environmental changes will be increasingly difficult without some characterization of habitat connectivity between these areas. Here we present a generalized model that prioritizes areas important for “climate connectivity” in California using a moving-window implementation of the Circuitscape model. This approach assesses the full landscape and connects climate “analogs” or areas of similar climate characteristics by traversing lands with low anthropogenic influence that also have a diversity of microclimatic conditions. This microclimatic diversity may provide live-in habitat for species as distributions gradually shift or may provide reduced exposure to extreme heat and water scarcity at shorter time scales. Nearly half of the linkages identified under current climate conditions were also identified as climate linkages. This approach to planning for climate connectivity can be used to evaluate the effectiveness of conservation actions to promote adaptation to climate change. Conserving or restoring these lands will provide greater assurance that California’s biodiversity will persist in the face of changing conditions.
2:10PM Modeling Seasonal Connectivity and Simulating Movement in a Developing Landscape
  Kathy Zeller, David Wattles, Laura Conlee, Stephen DeStefano
Many species adjust their habitat use and movement in relation to food availability, energetic and reproductive states, and human activity. This may result in changeable inferences about movement and connectivity during different seasons and times of day. Modeling these differences is important in understanding intra-annual variability in connectivity for species and the implications of different management actions on species persistence. We used GPS-telemetry collar data on black bears (Ursus americanus) to model movement and connectivity across the Commonwealth of Massachusetts for day and nighttime periods during spring, summer, and fall. We modeled movement with a multi-scale step selection function for each individual bear and estimated relative probability of movement for these different season/diel periods by projecting the step selection functions across the state. We combined the individual probability surfaces into a single predictive surface for each season/diel period using a spatially-weighted approach. We then used the inverse of these probability surfaces to estimate resistance. We modeled connectivity with resistant kernels, factorial least-cost paths, and by simulating the movement of individuals across the landscape. We assessed changes in connectivity among seasonal/diel periods as well as changes in predicted road crossing locations. Because the black bear population in Massachusetts is growing and expanding toward the greater Boston metropolitan area, we were also interested in predicting future bear movement patterns by incorporating different development and land use change scenarios into our resistance surfaces. Our results highlight intra-annual dynamism in connectivity and how future landscape change may affect black bear movement.
2:30PM Corridors for Climate Change Resiliency – Principles, Models, and Implementation
  Annika Keeley
Habitat loss and fragmentation are causing the loss of biodiversity worldwide, and climate change is exacerbating this problem. Connected protected and conserved areas are key for the effective conservation and management of biodiversity. Climate-wise connectivity specifically facilitates species range shifts in response to climate change. Concepts to design corridors to improve climate resilience include (1) connecting climate-analog sites, (2) reducing climate velocity in corridors by maximizing microclimate diversity and incorporating refugia in corridors, and (3) providing wide, live-in corridors between protected areas. A number of structural climate-wise connectivity modeling approaches are available, including climate-gradient corridors, land facet corridors, and naturalness-based corridors. Focal species-based models find climate-stable corridors or connect current to future habitat. Because it is unclear whether the connectivity priority areas resulting from different modeling approaches overlap or complement each other, we compared four approaches that have been applied to parts or all of California. Two model landscape structural connectivity, while the two others model connectivity for focal species. The variation in the modeling approaches, objectives, inputs, and landscape representations strongly affects modeled connectivity outputs, resulting in low agreement among areas prioritized for connectivity. Therefore, connectivity models should be selected based on the conservation objectives; a combination of models that represent different connectivity elements may be best. While modeling is important, it is only one part of connectivity conservation plans which are prepared to promote conservation action. An examination of attributes of plans from around the world revealed that nine factors influence plan implementation, including partnerships with stakeholders, leadership continuity, the existence of enabling legislation, focal species matched to the connectivity conservation plan objectives, sound science underlying the corridor designs and prioritization, adequate funding, and public outreach. Data on climate change velocity, refugia, and animal movement paths can be important for justifying connectivity projects with climate resilience objectives.
2:50PM Refreshment Break
3:20PM A Patch is Not a Population: Spatio-temporal Perspectives on Connectivity Dependent Processes
  Joseph Drake, Xavier Lambin, Chris Sutherland
The spatial distribution of species’ abundance and occurrence is an emergent property of connectivity, which has become a central metric for understanding ecological theory and applied conservation science, wildlife management, and landscape ecology. Understanding connectivity’s role in species persistence will be increasingly important in the face of continuing natural and escalating anthropogenic changes to communities, climate, and habitat. In general, the definition of connectivity is agreed upon. There is a structural component relating to the distribution of suitable and unsuitable habitat, and a functional component that relates to movement (often contextually through the landscape matrix). Connectivity, as a measure, should consider the interaction of both components. Although implied by ‘movement’, the distribution and abundance (or occurrence) of the focal organism, which itself is a spatio-temporally dynamic property of a landscape, is regularly overlooked when quantifying connectivity driven processes, such as dispersal. The ability to accurately quantify connectivity’s influence has be a longstanding challenge, further exacerbated by the underlying ecological processes and landscape scales across which connectivity plays out for populations. Drawing largely from recent advances in metapopulation ecology and incorporating developments from landscape ecological paradigms with spatially explicit hierarchical modeling, a promising novel framework for developing ecologically realistic, demographically informed connectivity metrics emerges. This framework can address current limitations of the reigning static connectivity paradigm.
3:40PM Synergism of Land-Use Change and Hydroclimatic Variability on Connectivity Dynamics in a Dryland System
  Mirela Tulbure, Robbi Bishop-Taylor, Mark Broich
Land use change and hydroclimatic variability affect spatiotemporal landscape connectivity dynamics, which are important for species movement, particularly in dryland landscapes affected by humans. Changes in land-use can strongly influence dispersal potential over time. However, prior research has mainly focused on the impacts of dynamics in the distribution of potential habitats, without incorporating resistance to movement due to changes in land use. To assess how changing land use and hydroclimatic variability affected landscape connectivity across time, we compared and contrasted 4 different scenarios, varying resistance to movement due to land-use change and habitat dynamics due to climate simultaneously and only one at a time. We used 8 time-steps of historical land-use together with a time series of surface water habitats derived from satellite data (1992-2011) over an ecologically significant and internationally relevant dryland region, the Murray-Darling Basin. We employed circuit theory to assign landscape features with ‘resistance’ costs that indicate their resistance to ecological movement for water-dependent organisms and network analysis based on graph theory. We show that land-use is important in determining landscape connectivity at local scale, whereas hydroclimatic variability dominated landscape connectivity at the basin scale. Areas where land-use played an important role in decreasing landscape connectivity coincided with areas where land-use changed from production from natural environments or irrigated agriculture to dryland agriculture. Our findings pinpoint areas where land-use change plays an important role in determining landscape connectivity and will help with prioritizing areas for management intervention. This is important as land-use can be managed more effectively compared to climate-mitigation actions, which may be intractable.
4:00PM Assessing Agreement Among Climate and Non-Climate Connectivity Networks in the Western U.S.
  Tristan Nunez
Prioritizing areas that provide ecological connectivity has become a central strategy in efforts to adapt to climate change. However, a wide variety of approaches have been proposed to assessing connectivity for climate change. How well do these different approaches agree with each other, both theoretically and spatially? In addition, many connectivity models and maps have been developed that do not explicitly account for climate-driven movements. Do non-climate connectivity networks also provide connectivity for climate change? We identify and describe areas of agreement among differing approaches to modeling and mapping corridor networks for species moving in response to climate change. We also assess the agreement of these areas to other corridor networks in the region that do not explicitly address climate change. These climate connectivity consensus maps can inform conservation investments and management intended to facilitate species movement both in the present and future.
4:20PM If You Remove It, What’s to Come: Predicting Ecological Outcomes of Removing Dams and Reconnecting Rivers
  Ryan Bellmore, George Pess, Jeffrey Duda, Jim E. O’Connor, Amy East, Melissa Foley, Andrew Wilcox, Jon Major, Patrick Shafroth, Sarah Morley, Christopher Magirl, Chauncey Anderson, James Evans, Christian Torgersen, Laura Craig
Dams can fragment river networks by severing the downstream transport of materials, and the up- and down-stream movement of organisms. In recent decades, however, there has been a proliferation of dam removals in the United States and Europe. One of the desired outcomes of many of these removals is to recovery of aquatic and riparian ecosystems by reconnecting rivers. To investigate this common objective, we synthesized information from empirical studies and ecological theory into conceptual models that depict key physical and biological linkages driving ecological responses to removing dams. We define models for three distinct spatial domains: upstream of the former reservoir, within the reservoir, and downstream of the removed dam. Emerging from these models are response trajectories that clarify potential pathways of ecological transitions in each domain. We illustrate that the responses are controlled by multiple causal pathways and feedback loops among physical and biological components of the ecosystem, creating recovery trajectories that are dynamic and nonlinear. In most cases, short-term effects are typically followed by longer-term responses that bring ecosystems to a new and frequently predictable ecological condition, which may or may not be similar to what existed prior to impoundment.
4:40PM Regional to National Connectivity Modeling Efforts: Examples and Lessons Learn
  Samuel Cushman
Given rapid changes to ecosystems at broad scales it has become urgently important to conduct assessments of wildlife population distribuiton, abundance, connectivity, gene flow and genetic diversity across political and geographical boundaries. In this talk I present overview and summaries of three large-scale habitat and connectivity modeling assessments across multi-State extents in the Western United States. The first example is from the Great Plains Landscape Conservation Cooperative, where we conducted the first LCC-wide assessment and prioritiztion of core areas and corridors for three species of native wildlife. The second example is from the Great Basin LCC, where we conducted a large-scale assessment of habitat quality, population core areas and corridors for eight species of native wildlife. The final example is the New Mexico Wildlife Linkage Assessment project which we completed in 2018 for the State of New Mexico, and which included assessing core areas and corridor location, strength and importance for five species across the full extent of the state. I discuss lessons learned and provide insights into approaches to effectively implement broad-scale habitat and connectivity assessments using rigorous empirical data and powerful modeling methods.

Organizers: Kathy Zeller, Megan Jennings
Supported by: TWS Spatial Ecology and Telemetry Working Group and Biodiversity Working Group

Location: Reno-Sparks CC Date: October 2, 2019 Time: 1:10 pm - 5:00 pm