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Download Pdf: Case Study: NatureServe's Climate Change Vulnerability Index for Species in Nevada (pg. 85)

Assessment Targets:

Nevada Natural Heritage is responsible for assessing the vulnerability of all 263 Conservation Priority species that were identified in the original Wildlife Action Plan. The species include 1 mussel, 74 snail, 40 fish, 7 amphibian, 20 reptile, 72 bird, and 49 mammal species. Once this assessment is completed, the outcome will contribute to habitat vulnerability models run by a partner organization. Nevada Natural Heritage hopes to eventually extend the vulnerabilityassessment to many more species, including plants and abundantly distributed species.

The Nevada assessment is restricted to a state-wide analysis. Developing future regional assessments that examine how species may expand into and retreat from states would be helpful to provide a more comprehensive picture of the complex changes in population size and location

taking place. Currently, though, existing funding mechanisms favor state-based approaches. The time scale for the species vulnerability assessments is mid-century. Mid-century represents a time frame that is before the major climate models and emissions scenarios begin to have widely divergent predictions, resulting in less uncertainty than for longer time horizon.

In terms of cost and time, once the distribution of natural history information on a species is researched and compiled—NatureServe has already done this for many species (available at NatureServe Explorer, http://www.natureserve.org/explorer)—it can take as little as 30–45 minutes to rank a species. The cost of this assessment will approximately $160,000.

Assessment Approach

The Nevada partners have divided the tasks according to each organization's strengths:

- The Department of Wildlife provides oversight and management of the project in coordination with the other partners. It organizes team meetings and helps solicit public comments on draft documents. The Department of Wildlife will also be responsible for interacting with the U.S. Fish and Wildlife Service to obtain formal approval for revisions to the Wildlife Action Plan.

- As stated above, the Nevada Natural Heritage Program is responsible for assessing the vulnerability of the individual Conservation Priority species to climate change.

- The Nature Conservancy will use a modeling approach to understand the vulnerability of Nevada habitats to climate change.

- The Lahontan Audubon Society will help facilitate workshops, work with the public, perform outreach activities, and help edit document drafts as they are writtten.

- The Great Basin Bird Observatory will use climate envelope models to estimate how bird distributions may shift as a result of climate change. Like the species assessments undertaken by Nevada Natural Heritage, [Image Missing] the results of these models will form input into The Nature Conservancy habitat models.Nevada Natural Heritage had a limited amount of funding and a short time frame for completing its task of reviewing the vulnerability of a large number of species. The program elected to use the Climate Change Vulnerability Index as a rapid and costefficient means of completing this task.The Index separates a species' vulnerability into two main components: exposure to climate change within its range and inherent sensitivity to climate change

(Williams et al. 2008) (see Figure C1.1). Data for these two components take the form of downscaled climate predictions across the range of the species within the assessment area (in this case, the state of Nevada) and scoring of the species against 17 factors related to its anticipated climate change sensitivity, such as dispersal ability and habitat specificity. Additional factors addressing exposure and adaptive capacity, such as natural or anthropogenic barriers to dispersal, as well as observed responses to climate change (if available)

are also included. These factors are all documented in the scientific literature to be correlates or predictors of vulnerability to climate change. The outcome is one of six possible Index categories: three Vulnerable (Extremely, Highly, and Moderately), two Not Vulnerable (Presumed Stable, Increase Likely), and one Insufficient Evidence. The Index complements standard conservation status assessments such as the NatureServe G- and S-rank system that contributed to species' designation as Conservation Priorities in the original Wildlife Action Plan. More information about the Index as well as the Index itself can be found at http://www.natureserve.org/ climatechange.Biologists from Nevada Natural Heritage used distribution and natural history information from their databases together with climate predictions downloaded from the ClimateWizard to complete assessments for all 263 Conservation Priority species. Next, they convened a panel of independent biologists familiar with Nevada wildlife to review their work and confirm or adjust how the factors were scored for each species. This process is currently ongoing and will result in final assessments that feed into habitat vulnerability models that will form another section of the revised Wildlife Action Plan.

Assessment Results

Like most of the world, Nevada will experience significant warming. Midcentury climate predictions suggest warming of 2.6 to 3.2 degrees Celsius and slight decreases or increases in precipitation in different parts of the state (Maurer et al. 2007). Results for a preliminary assessment of 216 vertebrates and mollusks listed as Conservation Priority species in the Nevada Wildlife Action Plan revealed that the Index sorted taxa into widely differing levels of vulnerability to climate change (Figure C1.2). Mollusks and fish were the most highly vulnerable groups, whereas some mammals and fish may increase their abundance or expand their ranges in Nevada as the climate warms. Demonstrated adaptation to a limited range of precipitation regimes, migration to or through a few restricted and potentially vulnerable locations or lack of regular distribution shifts in response to environmental conditions,and dependence on specific vulnerable aquatic/wetland habitats were the factors that most commonly contributed to vulnerability to climate change. Surprisingly, anticipated land-use changes designed to reduce greenhouse gas emissions as a means to mitigate climate change (such as solar, wind, and geothermal projects) are another factor contributing to vulnerability for some species due to associated habitat loss and fragmentation. Good dispersal ability, broad physical habitat requirements, migration to broad geographical areas or a tendency to shift distribution in response to environmental conditions, and demonstrated adaptation to a broad range of temperatures were the factors that most commonly decreased vulnerability. One noteworthy outcome is that the Index flagged a number of currently common species (i.e., NatureServe global conservation status rank G4 or G5) such as the American pika, bighorn sheep, and sagebrush vole as vulnerable to climate change. Thus, conservation status is not a reliable proxy for vulnerability to climate change.

Uncertainties

This assessment addressed uncertainty in two ways. One source of uncertainty concerns the differing projections by climate models of mid-century temperature and precipitation regimes in Nevada. The Nevada Natural Heritage Program addressed this uncertainty by using an average of an ensemble of 16 global circulation models as the exposure data for the Climate Change Vulnerability Index. The results therefore are not tied to any single climate model.A second source of uncertainty relates to how a particular species is scored against the Index sensitivity factors. Incomplete knowledge about a species' natural history and how it affects vulnerability for a particular factor can add uncertainty to the overall vulnerability score. The Index allows users to select more than one vulnerability value for each factor to reflect this uncertainty. The Index calculates an overall vulnerability score using an average of the values assigned for each factor, but also runs a Monte Carlo simulation to explore the probability that the overall score could change depending on what the "true" value might be for each factor scored with multiple values. The Index calculates a measure of confidence in species nformation (very high, high, moderate, or low) depending on the percentage of Monte Carlo runs that yield the same overall vulnerability score as calculated with the averaged data. For the Nevada species, the Monte Carlo simulations revealed that confidence in the Index score was very high or high for 61 percent, moderate for 27 percent, and low for 12 percent of the species (Young et al., in press).

Outcomes and Next Steps

As review of the assessments of the full set of Conservation Priority species is completed, The Nature Conservancy is assessing the vulnerability of key habitats to climate change. Subsequently, the partners will examine the Index results for each species, including the factors that most frequently led to species being categorized as vulnerable, the habitat model results, and the bird models produced by the Great Basin Bird Observatory to determine the management strategies necessary to create resilient wildlife populations and mitigate potential impacts to climate change. After receiving comments from the public, the partners will finalize the text of the climate change amendment to the Plan and submit it to the U.S. Fish and Wildlife Service for formal approval.An amended Wildlife Action Plan will not accomplish its objective unless its recommendations are put into practice. The partners responsible for preparing the climate change amendment also make up the implementation team for the Plan. As part of their work on the team, they will work to incorporate the recommendations from the Plan into ongoing private, state, and federal management activities. These actions will take many forms depending on the purview of each agency. The Nevada Natural Heritage Program will use the results of the vulnerability assessment to target particularly vulnerable species for monitoring. Comprehensive information on the locations and biological conditions of vulnerable species will contribute to proactive management decisions that could result in decreased conflicts between wildlife and development in the future. For example, monitoring data for a species that has limited dispersal ability or is encountering barriers to dispersal could provide an early indication of when translocations of populations should be considered.In conjunction with implementation activities, the partners are participating with the Heinz Center and the Wildlife Habitat Policy Research Program to use performance measures to monitor the effectiveness of management actions. For priority conservation goals, they have begun to develop logic models that pictorially describe pathways by which factors can affect a conservation goal. The models point to specific indicators that can be measured to monitor progress toward each conservation goal. This approach allows the partners to gauge their success and alter their strategies when needed, before wasting resources on ineffective actions.Challenges and Lessons LearnedOne challenge in developing the Index was deriving and calibrating criteria for diverse plants and animals. Research in the past decade has led to a substantial increase in understanding about the factors that correlate with climate change vulnerability, but analyses are typically available only for selected taxonomic groups. Assembling an interdisciplinary team to develop, test, and refine the Index proved necessary to address how the myriad natural history attributes of North American plants and animals confer increased or decreased vulnerability to climate change.

Nevada's approach of having a general biologist perform preliminary assessments and then inviting specialists to review the results in a workshop setting proved to be successful. The specialists provided a broader interpretation of the criteria, and their individual expertise with particular species went beyond information found in the published literature. The general biologist provided leadership for the process and ensured that the criteria were applied consistently across taxa. Also, an advantage to carrying out the assessments within the Nevada Natural Heritage Program was the easy access to spatial information about the locations of populations of Conservation Priority Species for calculating exposure.

Citation

(2011). Case Study: NatureServe's Climate Change Vulnerability Index for Species in Nevada - NWF.