Mapping Wildland Values and Climate Change Vulnerability
Undeveloped natural areas—also known as wildlands—aren’t just empty land: these areas are essential for the health and sustainability of the environment and the ecosystems it supports. Benefits from wildlands include habitat for diverse plant and animal species, water and air purification, and outdoor recreation for people. Conserving wildlands and their assets has been an important conservation goal for decades.
Historically, conservationists have focused on protecting plants and animals within reserves such as national parks and wilderness areas. They also work to restore degraded lands that might be missing key features or species. For example, conservationists have worked to re-establish open, park-like forests of ponderosa pine, and reintroduced wolves to Yellowstone National Park. However, climate change and some other problems—invasive species, for instance—cross reserve boundaries and create moving targets for restoration, leading many ecological scientists to rethink traditional conservation strategies.
Can nature take care of itself?
Wilderness advocates and most conservation scientists have long held that nature can take care of itself. They assert that a "hands off" strategy may be the best way to maintain all of nature’s diversity.
Impacts related to climate change, though, are causing some to question that idea. Can nature take care of itself as conditions change, or when exotic species such as gypsy moths, cheatgrass, or kudzu invade? Or must we intervene and manage nature?
Establishing restoration benchmarks in a changing climate
Restoration ecologists who work to restore degraded lands sometimes struggle to establish benchmarks. What does "restoration" look like in different locations? What targets should they set? Many efforts aim to re-establish the original suite of species that existed at a site before humans developed lands, harvested species, introduced exotics, and dammed rivers. However, some ecologists argue that a historical target for restoration is no longer valid as climate changes. After all, it makes little sense to attempt to restore species to areas in which they can no longer survive. These ecologists suggest that we should plan for the future instead; they recommend planting species suited to the projected climate conditions of tomorrow.
The need for a diverse portfolio
All of these arguments have led some to question the concept of naturalness altogether, and ecologists find they must wrestle with some philosophical questions. Ideally, they hope to sustain all of nature’s diversity and the services humans draw from it. Realistically, they recognize this may not be possible in the face of climate change.
Greg Aplet and Peter McKinley, ecologists at the non-profit conservation organization The Wilderness Society, increasingly recognize that no single approach to conservation is universally applicable. They've come to believe that a diverse portfolio of conservation strategies makes the most sense, in part because it enables them to nurture a range of options that span the range of uncertainty for future conditions.
A national assessment for wilderness protection and restoration
Working with data sources from AdaptWest, the U.S. Forest Service, the U.S. Geological Survey, the U.S. Census Bureau, NatureServe, and others, scientists at The Wilderness Society led by ecologist Travis Belote conducted a national assessment of conservation values and climate change vulnerability. Their goal was to determine where to emphasize certain strategies—from wilderness protection to novel restoration approaches—based on the existing conditions of the land as well as projected future climate conditions.
In the assessment, Belote quantified and mapped conservation values for lands based on several factors:
- How much human modification the land has experienced (a measure of its "wildness"),
- How important the land is as a natural linkage between protected areas,
- How well the land's ecosystems are represented within existing protected areas, and
- Whether a place is rich in rare and endemic species.
When combined, these factors produce a composite map of wildland conservation values. The map highlights wild, connected places that encompass a comprehensive range of ecosystems or rare species: it shows patterns that can help identify conservation priorities and provide a quantitative estimate of land's existing value.
Incorporating climate change projections
Overlaying mapped wildland values with climate change projections can provide guidance about which conservation strategies might be emphasized in an area, and how a chosen strategy might be tailored based on projections of future climate conditions.
Belote used the following projections to assess climate change vulnerability:
- Climate velocity (how far species will have to move to keep up with climate change),
- Climate dissimilarity (how different the climate is expected to be),
- Projected shifts in species and biomes (regions of the world with similar climate, animals, and plants), and
- Geophysical diversity.
The combination of wildland values and climate vulnerability represented in the map can help ecologists decide where to emphasize restoration, innovation, and protection in reserves. In other words, the combined information can help conservationists decide where to implement which conservation strategy within their portfolios.
Applying the assessment
In areas with low wildland values and low climate vulnerability (yellow, lower left), the assessment recommends that conservationists emphasize restoration that maintains a focus on historical components of nature. These areas are likely more degraded and altered, are not critical for connecting protected areas, or are already well-represented in protected areas. These regions may not experience much impact from climate change, so a historical model for restoration may be appropriate.
Areas with low wildland values and high vulnerability (red, upper left) may benefit from an emphasis on more innovative approaches. These areas have lower values, have experienced more degradation, and are expected to experience greater impacts from climate change. In these areas, attempting historical restoration may be less useful because the future climate is expected to be very different than the past. Therefore, innovative approaches to conservation such as planting “off-site” native species that are better suited to the projected future climate may be successful.
In areas where wildland values are high and climate vulnerability is low (green, lower right), traditional wilderness-like protection may suffice. These places are still relatively wild and intact, are important for connecting protected areas, and are composed of habitat types not already well-protected in reserves. Climate in these places may be relatively stable and wilderness-like reserves may provide sufficient refuge for both plants and animals. Establishing reserves where we observe nature’s solutions to climate or other challenges may be most relevant and important to emphasize in these areas.
Areas where both wildland conservation values and climate vulnerability values are high (dark blue, upper right) present a challenge. These important lands are relatively intact, important corridors, and are underrepresented in protected areas, but they may experience substantially new conditions as climate changes. Given the uncertainties associated with climate change and the unintended consequences of management, it isn’t easy to identify a single best solution. In these areas, the assessment recommends considering all three adaptation strategies: restoration, innovation, and observation. Zones allocated to each strategy would maintain connectivity and protect ecosystems from other stressors, but would apply adaptation options consistent with each strategy to address the observed impacts of climate change. In other words, the assessment recommends that conservation managers work to alleviate or prevent potential stressors to nature, but also recognize they that intervention and flexible management plans may be necessary to address the challenges of climate change.
Fostering a climate-resilient national wildlands system
The national assessment identifies priorities for traditional conservation strategies, recommending where to protect, connect, and restore wildlands. By incorporating climate change models, the approach can also identify where to emphasize different climate adaptation strategies and where to spread risk among multiple strategies. Ultimately, this approach can help foster a national wildlands system that’s more prepared to handle the projected consequences of climate change.
As natural resource managers embark on updating land management plans, the assessments and frameworks presented here may provide important data to help manage for resilient landscapes. A number of climate adaptation frameworks are being proposed, and analyses such as this one conducted by The Wilderness Society may provide empirical evaluations that protect wildland conservation values while acknowledging the need for management interventions in lands relatively vulnerable to the impacts of a changing climate.
- Aycrigg, J. L., A. Davidson, L. K. Svancara, K. J. Gergely, A. McKerrow, and J. M. Scott, 2013: Representation of Ecological Systems within the Protected Areas Network of the Continental United States. PLoS ONE 8(1):e54689.
- Aycrigg, J. L., C. Groves, J. A. Hilty, J. M. Scott, P. Beier, D. A. Boyce, D. Figg, H. Hamilton, G. Machlis, K. Muller, K. V. Rosenberg, R. M. Sauvajot, M. Shaffer, and R. Wentworth, 2016: Completing the System: Opportunities and Challenges for a National Habitat Conservation System. BioScience XX: 1–11.
- Belote, R. T., M. S. Dietz, B. H. McRae, D. M. Theobald, M. L. McClure, G. H. Irwin, P. S. McKinley, J. A. Gage, and G. H. Aplet, 2016: Identifying Corridors among Large Protected Areas in the United States. PLoS ONE 11(4):e0154223.
- Carroll, C., J. J. Lawler, D. R. Roberts, and A. Hamann, 2015: Biotic and Climatic Velocity Identify Contrasting Areas of Vulnerability to Climate Change. PLoS ONE 10(10): e0140486.
- Jenkins, C. N., K. S. Van Houtan, S. L. Pimmc, and J. O. Sexton, 2015: US protected lands mismatch biodiversity priorities. Proceedings of the National Academy of Sciences of the United States of America, 112(16), 5081–5086.
- Theobald, D. M., 2013: A general model to quantify ecological integrity for landscape assessments and US application. Landscape Ecology 28:1859–1874.