H2020 VULNERAWEB Project: Web platform for predicting the climate vulnerability of species
- Type Project
- Status Filled
- Execution 2020 -2022
- Assigned Budget 160.932,48 €
- Scope Europeo
- Autonomous community Madrid, Comunidad de
- Main source of financing Horizon 2020
- Project website http://www.vulneraweb.com/
How, how much, why, when, and where are species affected by climate change? The answers to these questions are key to assessing a species' vulnerability to climate change. This is the first step in developing conservation strategies. The EU-funded VULNERAWEB project aims to improve current predictions by applying the concepts of the heat death curve (TDC) and the voluntary thermal maximum (VTM). The TDC represents all possible combinations of temperature and time. The VTM represents a temperature objectively identified by organisms as stressful. The results of preliminary analyses suggest that these tools increase the power of the forecasts produced. The project will also create an online platform to guide the collection and curation of relevant data and to engage climate vulnerability experts worldwide.
To answer the first question, this MSCA project has completed the compilation of the world's largest database of animal thermal tolerances to date and of the geographic thermal boundaries for these species. Using these datasets, we conducted several analyses to identify: a) whether species' heat tolerance constrains maximum ambient temperatures at known warm edges for each species during the hottest time of year (hereafter Tmax), using different estimates of heat tolerance and Tmax; b) whether Tmax values are correlated across species' geographic thermal boundaries; and c) whether constraints will be stronger for species whose thermal tolerance is most challenged by Tmax. Heat tolerances, as measured so far, very often constrain animals' geographic thermal boundaries (e.g., Fig. 1). However, they do so in a heterogeneous manner; the constraint is always stronger for those species that face higher temperatures due to their tolerance at their warm edges.
In the figure, these taxa are represented by a red line, while species less challenged by high temperatures at their warm edges are represented by the orange and blue lines. Surprisingly, reptiles appear to be less geographically constrained by their thermal tolerance than other taxa. Moreover, many fish have reached such a high CTmax that they are freed from heat constraints on their geographic distribution, contributing to a sigmoid relationship of CTmax with Tmax that contrasts with terrestrial taxa. The relationships found undermine widespread practices for estimating species range shifts and climate vulnerability based on less useful parameters of thermal tolerance, or on purely geographic models. Global patterns of heat constraints across species' geographic ranges should be refined once potential confounders can be more thoroughly controlled (e.g., plasticity, local adaptation, biotic interactions), particularly for species groups and parameters that showed weaker correlations.
To this end, it remains essential to gather more experimental data on heat tolerance at the geographic thermal limits of species. The second problem has been addressed by comparing, for the first time, how different representations of thermal tolerance (different thermal tolerance parameters versus a time-to-death x temperature curve) might detect different geographic patterns in expected thermal vulnerability.
These studies include: a) a North American lizard, analyzing how dehydration altered its thermal tolerance; b) the geography of thermal vulnerability in tropical ants and lizards; and c) observing thermal acclimation times in tropical tadpoles.
The results of these studies suggest that the geography of thermal vulnerability estimates is highly sensitive to the parameter used and its intrinsic variability. Therefore, future reports on species' thermal vulnerability must balance the need for a complete representation of thermal tolerance—which is slow to obtain and stressful for animals because it involves multiple tolerance experiments—with the need to make useful predictions based on more practical and less stressful measures of thermal tolerance. Finally, to leverage the knowledge gained and disseminate robust and ethical methods for measuring thermal tolerance, this project led to the creation of the VulneraWeb platform (www.vulneraweb.com).
This is an online collaborative platform that uses the supercomputing power provided by the CSIC's Finis Terrae III facility (https://www.cesga.es/cesga/el-cesga/(Opens in a new window)) to map climate-vulnerable animal populations around the world (e.g., Fig. 2). Different aspects of the issue of species vulnerability to climate change and the platform's capabilities have been presented both in person and online, from local to international scales, through talks for schools, seminars, and international online conferences. The platform and its channels on Instagram (vulnerawebglobal) and Twitter (vulneraweb) have been created and updated with new features, with the participation of a gender-balanced team of international students.
In addition to uncovering new global ecogeographic rules (the heterogeneous effects of thermal tolerance on the geographic thermal limits of animal species around the world), the analyses conducted informed the most practical ways to estimate thermal vulnerability among animals, and this knowledge can now be transferred through the services offered by the platform. Currently, VulneraWeb is expanding its network and is ready to prepare reports for conservation organizations, from international to local, such as the IUCN and local municipalities currently engaged in planning their adaptation to climate change.
Accurate Climate Vulnerability Assessments (CVAs) for species are key to allocating the massive investments needed to achieve Europe's H2020 and IUCN climate adaptation targets. However, this begins with identifying locations that are climatically unsuitable for supporting a species' populations (e.g., those with excessively high temperatures).
This information identifies sites where current land use will no longer be suitable because the climate will be too extreme for the species relevant to their use (e.g., endangered species in reserves, game species, or productive breeds). This MSCA project has analyzed different ways in which heat tolerance can restrict species distributions. A central question that remains to be resolved is whether heat tolerance, as measured by scientists so far, is generally capable of identifying thermal restrictions on the geographic distribution of species. A second fundamental problem is to improve the understanding of how thermal tolerance interacts with other factors, such as the length of exposure to stressful temperatures, on thermal tolerance.
Reliable climate vulnerability (CV) forecasts for species are key to achieving the objectives of the Horizon 2020 program. However, the complexity of CV and the enormous amount of data required challenge current approaches and data availability. The most advanced forecasts use measures of species' thermal tolerance and their ability to avoid environmental overheating. However, these models are based on two fundamental premises. First, that a single combination of temperature and exposure time will induce population declines.
However, countless combinations of temperature and exposure time can, in fact, kill individuals in a population. A second premise is that known thermal tolerance parameters can identify thermal limits for species' geographic distributions. Finally, regardless of whether these premises are true or not, most species lack the data necessary to model their vulnerability to climate change. During this project, I will apply, for the first time, the concepts of the heat death curve (HDC) and the voluntary thermal maximum (VTM) to improve forecasts.
The TDC represents all possible combinations of temperature and time that cause harm to populations, and the VTM represents a temperature objectively identified by organisms as stressful. My preliminary analyses have shown that these tools multiply the effectiveness of the generated forecasts and prevent drastic biases introduced by more traditional parameters. Second, I will test, on a global scale, whether the known limits of animals' geographic distributions are determined by known measures of their thermal tolerance. Finally, to channel global efforts toward collecting the necessary data on species and generating robust forecasts, I will create an online platform to engage climate vulnerability experts from around the world through a reward-for-action system. This web platform will guide the collection and management of relevant data and provide FCV using the best available models and advice from international experts.
Climate change isn't going to hit all species populations at once, but rather will first affect the most vulnerable populations of each species, explains Agustín Camacho Guerrero, a former researcher at the Department of Conservation Ecology at the Spanish National Research Council (Opens in a new window) in Madrid. "Therefore, we need to know which species populations will be overwhelmed when exposed to rising ambient temperatures. Particularly, we need to know this across all geographic ranges where these species exist." "To make this knowledge actionable, we need accurate maps of both ambient temperatures and species' thermal tolerance—the maximum temperatures they can withstand. This way, we can know which populations are most likely to exceed tolerance in a particular location." Global platform to map species resilience The VULNERAWEB (Opens in a new window) platform, built from the ground up within the framework of the project, compiles this data to produce predictive maps of vulnerable species globally.
These can be used, for example, by nature reserve managers or others who receive public funding to protect biodiversity. Camacho (Opens in a new window), whose research was carried out with support from the Marie Skłodowska-Curie Actions Programme (Opens in a new window), began by collecting thermal tolerance data by reviewing the scientific literature on as many species as possible. These included marine fish, arthropods, amphibians, reptiles, birds, and mammals. But scientists measure thermal tolerance in different ways, which don't always identify the maximum temperatures at which species populations are viable. "For some species, we have comprehensive data on thermal tolerance. For others, we have nothing apart from the locations where they live," Camacho explains. "I had to prepare and adapt models to take this into account." A large amount of laboratory testing was also carried out prior to the project during the field trips she was part of. Different ways of measuring thermal tolerance The thermal tolerance measurements from the scientific literature were divided into three groups.
The first included experiments in which temperatures were raised to a level at which an animal loses locomotor ability. "This is called the 'critical thermal maximum,'" Camacho adds. Comparisons were made between the "critical thermal maximum" of marine fish, arthropods, amphibians, and reptiles. In a second group, temperatures that signal the limits of optimal physiological performance were recorded. "Even if an animal is capable of moving, after a higher thermal level is exceeded, the animal begins to consume too much water and energy," she notes. This group includes birds, mammals, and lizards. In a third group, thermal tolerance was identified from animal behavior, such as panting.
Different behaviors were compared within a particular group of species: lizards. To see if any of these different measures of thermal tolerance were able to predict the warmest temperatures at which species could maintain their populations, these measures were compared to the warmest temperatures recorded within each species' geographic range. The maximum temperature was recorded in the shade, in a shelter 10 cm underground, or on exposed rocks. "That's a lot of testing," Camacho says. But while some measures of thermal tolerance were poor predictors of thermal constraints in animals, others performed well and, notably, were better than simply using the species' geographic locations.
The VULNERAWEB platform now includes 1,000 species. "We see this as a 'seed' database that can be expanded," adds Camacho. Modeling Time to Death The maximum tolerable temperature isn't the only important factor; there's also the length of time animals are exposed to stressful heat. Therefore, theoretical models of the decrease in time to death as temperature increases were compared with indicators such as loss of locomotion and avoidance of heat sources. "This creates several different maps, different models, based on these different thermal parameters," says Camacho.
- AGENCIA ESTATAL CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS
- CORDIS project factsheet (pdf)
- Does heat tolerance really predict the geographic thermal limits of animals?
- The critical and voluntary thermal limits of leaf-cutter ants show complex resp…
- Phenology and plasticity can prevent clinal adaptation in thermal tolerance acr…
- Species diversity and biogeography of an ancient clade of frogs from the Guiana…
- Website of the STATE AGENCY OF THE HIGHER COUNCIL FOR SCIENTIFIC RESEARCH
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