Identifying Climate Refugia Research Articles

Pre-drought effects on northern temperate trees and vine invasion in forest gaps hindering regeneration

Northern temperate coniferous forests serve as crucial connectors between boreal and temperate forests, yet they are vulnerable to various stressors such as climate change and human activities. Severe drought poses a significant threat to plant species within these forests, prompting recent research into its impacts. However, many studies lack explicit definitions of post-disturbance vegetation processes and fail to identify potential interactions with disturbance factors, necessitating comprehensive discussions. This study examines the effects of drought on tree growth patterns of the main dominant species in northern temperate regions: Abies nephrolepis and Picea jezoensis, along with two commonly associated Betula ermanii, and Quercus mongolica. Additionally, new disturbance factors in forests inhabited by these species (A. nephrolepis and P. jezoensis) were evaluated based on community classification. The study sites were located in the Mt. Baekdu (Changbai) and South Korea regions, which are positioned at the southern limit of the phytogeographical patterns of target species. Results indicate that A. nephrolepis and P. jezoensis exhibit high levels of recovery and resilience, while B. ermanii and Q. mongolica demonstrate high resistance. Species-specific responses align with drought intensity, with resistance, recovery, and resilience decreasing notably with increasing pre-drought radial growth. South Korean forests, the invasion of the vine species Tripterygium regelii after the death of A. nephrolepis in the overstory vegetation threatens the regeneration of new trees. However, certain environmental factors, such as high rock exposure and dense overstory canopy, limit vine invasion. Based on the results, pre-drought radial growth emerges as a key determinant in how trees respond to drought. Additionally, the results suggest the potential for new disturbances to emerge in forest gaps due to overstory vegetation mortality induced by global warming. These findings contribute to a deeper understanding of increasing drought stress, aid in identifying climate refugia, and inform conservation priorities based on habitat characteristics.

Prioritizing conservation efforts based on future habitat availability and accessibility under climate change.

The potential for species to shift their ranges to avoid extinction is contingent on the future availability and accessibility of habitats with analogous climates. To develop conservation strategies, many previous researchers used a single method that considered individual factors; a few combined 2 factors. Primarily, these studies focused on identifying climate refugia or climatically connected and spatially fixed areas, ignoring the range shifting process of animals. We quantified future habitat availability (based on species occurrence, climate data, land cover, and elevation) and accessibility (based on climate velocity) under climate change (4 scenarios) of migratory birds across the Yangtze River basin (YRB). Then, we assessed species' range-shift potential and identified conservation priority areas for migratory birds in the 2050s with a network analysis. Our results suggested that medium (i.e., 5-10km/year) and high (i.e., ≥ 10km/year) climate velocity would threaten 18.65% and 8.37% of stable habitat, respectively. Even with low (i.e., 0-5km/year) climate velocity, 50.15% of climate-velocity-identified destinations were less available than their source habitats. Based on our integration of habitat availability and accessibility, we identified a few areas of critical importance for conservation, mainly in Sichuan and the middle to lower reaches of the YRB. Overall, we identified the differences between habitat availability and accessibility in capturing biological responses to climate change. More importantly, we accounted for the dynamic process of species' range shifts, which must be considered to identify conservation priority areas. Our method informs forecasting of climate-driven distribution shifts and conservation priorities.

Cold-water habitats, climate refugia, and their utility for conserving salmonid fishes

Anthropogenic climate change is warming global temperatures, with significant implications for salmonid fishes that depend on the availability of cold water during one or more life stages. Along the southern range extents of many species, and elsewhere that warm temperatures are increasingly problematic, identification and protection or restoration of habitats that may serve as climate refugia where local populations can persist is emerging as an important conservation tactic. In this perspective piece, we address the concept and utility of climate refugia—drawing a distinction with the more commonly considered thermal refuges—describe technological advances that enable accurate temperature mapping and species distribution modeling in lotic environments, and outline key uncertainties and opportunities to chart a constructive path forward on a topic that will continue to grow in importance. Identifying climate refugia is not a panacea for salmonid conservation, but we argue that there are tangible benefits to doing so, not the least of which are the options it affords for thinking and acting strategically within the context of a changing climate this century.

Targeting current species ranges and carbon stocks fails to conserve biodiversity in a changing climate: opportunities to support climate adaptation under 30 × 30

Protecting areas for climate adaptation will be essential to ensuring greater opportunity for species conservation well into the future. However, many proposals for protected areas expansion focus on our understanding of current spatial patterns, which may be ineffective surrogates for future needs. A science-driven call to address the biodiversity and climate crises by conserving at least 30% of lands and waters by 2030, 30 × 30, presents new opportunities to inform the siting of new protections globally and in the US. Here we identify climate refugia and corridors based on a weighted combination of currently available models; compare them to current biodiversity hotspots and carbon-rich areas to understand how 30 × 30 protections siting may be biased by data omission; and compare identified refugia and corridors to the protected areas database to assess current levels of protection. Available data indicate that 20.5% and 27.5% of identified climate adaptation areas (refugia and/or corridor) coincides with current imperiled species hotspots and carbon-rich areas, respectively. With only 12.5% of climate refugia and corridors protected, a continued focus on current spatial patterns in species and carbon richness will not inherently conserve places critical for climate adaptation. However, there is ample opportunity for establishing future-minded protections: 52% of the contiguous US falls into the top quartile of values for at least one class of climate refugia. Nearly 27% is already part of the protected areas network but managed for multiple uses that may limit their ability to contribute to the goals of 30 × 30. Additionally, nearly two-thirds of nationally identified refugia coincide with ecoregion-specific refugia suggesting representation of nearly all ecoregions in national efforts focused on conserving climate refugia. Based on these results, we recommend that land planners and managers make more explicit policy priorities and strategic decisions for future-minded protections and climate adaptation.

Identifying climate refugia and its potential impact on Tibetan brown bear (Ursus arctos pruinosus) in Sanjiangyuan National Park, China.

Climate change has direct impacts on wildlife and future biodiversity protection efforts. Vulnerability assessment and habitat connectivity analyses are necessary for drafting effective conservation strategies for threatened species such as the Tibetan brown bear (Ursus arctos pruinosus). We used the maximum entropy (MaxEnt) model to assess the current (1950–2000) and future (2041–2060) habitat suitability by combining bioclimatic and environmental variables, and identified potential climate refugia for Tibetan brown bears in Sanjiangyuan National Park, China. Next, we selected Circuit model to simulate potential migration paths based on current and future climatically suitable habitat. Results indicate a total area of potential suitable habitat under the current climate scenario of approximately 31,649.46 km2, of which 28,778.29 km2 would be unsuitable by the 2050s. Potentially suitable habitat under the future climate scenario was projected to cover an area of 23,738.6 km2. Climate refugia occupied 2,871.17 km2, primarily in the midwestern and northeastern regions of Yangtze River Zone, as well as the northern region of Yellow River Zone. The altitude of climate refugia ranged from 4,307 to 5,524 m, with 52.93% lying at altitudes between 4,300 and 4,600 m. Refugia were mainly distributed on bare rock, alpine steppe, and alpine meadow. Corridors linking areas of potentially suitable brown bear habitat and a substantial portion of paths with low‐resistance value were distributed in climate refugia. We recommend various actions to ameliorate the impact of climate change on brown bears, such as protecting climatically suitable habitat, establishing habitat corridors, restructuring conservation areas, and strengthening monitoring efforts.

Congruence between future distribution models and empirical data for an iconic species at Joshua Tree National Park

AbstractU.S. national parks protect a natural heritage of global significance; those parks, especially those in the arid southwest, are threatened by climate change. Identifying climate refugia within our national parks using not only statistical models, but also validating predictions using robust field data should provide focus for managers in their stewardship of parks’ biological resources. In the region surrounding Joshua Tree National Park (JTNP), which straddles the Colorado and Mojave deserts in southern California, previous research has predicted the widespread demise of its namesake iconic species, the Joshua tree (Yucca brevifolia) due to climate change. In order to assess whether climate refugia exist for Joshua trees in the future at JTNP, we employed both field measurements and statistical models. We used current distribution point data together with historic climate data, to match conditions when the existing Joshua trees established, in order to predict the distribution of continuously suitable conditions (refugia) at the end‐of‐century. While the high and moderate mitigation could result in refugia for approximately 19% and 14% of the original area within JTNP, respectively, the business‐as‐usual scenario indicated an almost complete elimination of Joshua trees from the park. In order to validate model predictions, using teams of community scientists, we measured the demographic patterns of Joshua tree stands from low to upper elevations within JTNP. Recruitment within stands shows a strong concordance with modeled climate refugia; high‐recruiting stands were within or closer to modeled refugia and in areas with lower climatic water deficit, higher precipitation, and lower maximum temperature than low‐recruiting stands. These findings most importantly indicate the importance of regional to global mitigation strategies for carbon emissions, as reflected in the difference between maintenance of refugia vs. an almost complete elimination of the species from the park by the end‐of‐century. This also underscores the need to protect areas predicted to support refugia from multiple management threats. Rather than an ominous prediction of extinction, climate refugia provide land stewards with targets for focusing protective management, giving desert biodiversity places to weather the future.

Identifying climate refugia and its potential impact on small population of Asian elephant (Elephas maximus) in China

Climate change is anticipated to alter both wildlife distributions and their movement patterns, due to shifts, loss, and fragmentation of habitat, increasing the risk of extinction for many endangered species. Therefore, climate change must be integrated into wildlife conservation strategies. Using the case study of Asian elephants in China, we used the maximum entropy model to assess habitat suitability by incorporating current and future (2050s) bioclimatic and environmental variables. We then delineated climate refugia where suitable habitat overlapped under both scenarios. Then, we use circuit theory model to analyse potential movement by elephants (through measuring current flow), by linking current habitats and future habitats. Our results showed that current suitable habitat covers an area of about 5228.18 km2, of which 45.71% is projected to be lost by 2050 due to climate change, leaving 2836.76 km2. Just 327.2 km2 new suitable habitat was projected in 2050s. Climate refugia covered 2509.56 km2, and were mainly located in Mengyang and Shangyong reserves and their surrounding regions. Moreover, maps connecting suitable habitats under current and 2050s identified different regions delineated as important for the potential movement of elephants, which mainly distributed in regions of climate refugia. We proposed various actions to ameliorate the predicted impacts of climate change on Asian elephant, including protecting suitable habitat within regions where elephant are currently distributed, establishing corridors between areas where elephant are distributed, creating cross-boundary protected areas, and translocating elephants. This approach could be applied to the conservation planning of other wildlife, especially for umbrella species that support high biodiversity.

Identifying Climate Refugia: A Framework to Inform Conservation Strategies for Agassiz's Desert Tortoise in a Warmer Future

Abstract Agassiz's desert tortoise, Gopherus agassizii, faces threats from climate change. With limited mobility to move long distances to more-suitable habitat as climate change advances, whether protecting tortoises in situ or translocating them out of harm's way, a critical conservation task is identifying refugia, lands that will remain suitable under the current climate and the projected, end of the 21st Century warming and drying. While researchers have modeled tortoise habitat suitability, they have done so at coarse scales and did not identify climate refugia that may become apparent only with a fine-scale approach. It is at that scale that managers can implement measures that will foster habitat protection for tortoises throughout their current range. In this case study, we employed fine-scale habitat suitability modeling to identify current habitat and climate refugia within and surrounding the Marine Corps Air Ground Combat Center (MCAGCC) at Twentynine Palms, California. We modeled nearly 284,...

Climatic characterization of forest zones across administrative boundaries improves conservation planning

Aim This paper demonstrates methods to extend standardized vegetation zone descriptions and mapped distributions across political boundaries. An extended climate niche for North America's Coastal Douglas-fir (CDF) forest zone is determined and projected to evaluate its potential distribution under a changing climate and to identify climate refugia for conservation planning. Location Pacific Northwest temperate rain forest in British Columbia (BC), CA, and nearby Washington (WA) and Oregon (OR), US. Methods Using a combination of ecosystem polygon mapping and ecological plot data with climate interpolation tools, forests characterized as CDF under BC's biogeoclimatic ecosystem classification system were identified in the neighbouring US. Current (baseline) limits to CDF distribution were identified and used to map its potential distribution and climate refugia under future climate conditions using ensemble Global Climate Model projections. Results The extended CDF climate niche covers 76 725 km2 under baseline conditions, with the majority of the area in the Pacific Northwest US. The extended CDF forest zone includes a vegetation assemblage consistent with existing definitions of BC's CDF moist maritime subzone, but also an additional vegetation assemblage representing a drier maritime subzone. Projections of future climate suggest a northerly shift (~150 km) and a decrease (−91.5%) in overall CDF area. Climate refugia are projected for discontinuous patches of CDF forest on Vancouver Island and adjacent mainland. Conclusions This project combined georeferenced ecological plot data and digital maps, thereby facilitating the international mapping of ecosystem distributions in adjacent administrative areas that do not currently use the same ecosystem classification and mapping systems. This approach and the concept of climate niche definition, distribution and persistence are applicable to the management, restoration and conservation of plant communities, particularly in evaluating future ecosystem range shifts and disruptions associated with a changing climate. The potential for dramatic reductions in the range of the Coastal Douglas-fir zone, with persistence in <15% of its current area, suggest that most of the extended CDF zone is marginally suitable for the characteristic CDF ecosystems and that slight shifts in climate or disturbance regime may greatly alter the character of the vegetation. The full climatic niche for British Columbia's Coastal Douglas-fir forest zone is determined from its mapped distribution and georeferenced plot data in the neighbouring USA. A new subzone is characterized, and the potential distribution of the extended zone is projected under a changing climate to identify climate refugia. For sensitive ecosystems with multi-jurisdictional distributions, this approach helps focus conservation efforts.