• Energy Research

AbstractWhile the effects of climate (long‐term, prevailing weather) on species abundance, range and genetic diversity have been widely studied, short‐term, localized variations in atmospheric conditions (i.e., weather) can also rapidly alter species’ geographical ranges and population sizes, but little is known about how they affect genetic diversity. We investigated the relationship between weather and range‐wide genetic diversity in a marsupial, Bettongia gaimardi, using dynamic species distribution models (SDMs). Genetic diversity was lower in parts of the range where the weather‐based SDM predicted high variability in probability of B. gaimardi occurrence during 1950–2009. This is probably an effect of lower population sizes and extinction–recolonization cycles in places with highly variable weather. Spatial variation in genetic diversity was also better predicted by mean probabilities of B. gaimardi occurrence from weather‐ than climate‐based SDMs. Our results illustrate the importance of weather in driving population dynamics and species distributions on decadal timescales and thereby in affecting genetic diversity. Modelling the links between changing weather patterns, species distributions and genetic diversity will allow researchers to better forecast biological impacts of climate change.

AbstractWhile the effects of climate (long‐term, prevailing weather) on species abundance, range and genetic diversity have been widely studied, short‐term, localized variations in atmospheric conditions (i.e., weather) can also rapidly alter species’ geographical ranges and population sizes, but little is known about how they affect genetic diversity. We investigated the relationship between weather and range‐wide genetic diversity in a marsupial, Bettongia gaimardi, using dynamic species distribution models (SDMs). Genetic diversity was lower in parts of the range where the weather‐based SDM predicted high variability in probability of B. gaimardi occurrence during 1950–2009. This is probably an effect of lower population sizes and extinction–recolonization cycles in places with highly variable weather. Spatial variation in genetic diversity was also better predicted by mean probabilities of B. gaimardi occurrence from weather‐ than climate‐based SDMs. Our results illustrate the importance of weather in driving population dynamics and species distributions on decadal timescales and thereby in affecting genetic diversity. Modelling the links between changing weather patterns, species distributions and genetic diversity will allow researchers to better forecast biological impacts of climate change.

Biodiversity is essential to human well-being, but people have been reducing biodiversity throughout human history. Loss of species and degradation of ecosystems are likely to further accelerate in the coming years. Our understanding of this crisis is now clear, and world leaders have pledged to avert it. Nonetheless, global goals to reduce the rate of biodiversity loss have mostly not been achieved. However, many examples of conservation success show that losses can be halted and even reversed. Building on these lessons to turn the tide of biodiversity loss will require bold and innovative action to transform historical relationships between human populations and nature.

Biodiversity is essential to human well-being, but people have been reducing biodiversity throughout human history. Loss of species and degradation of ecosystems are likely to further accelerate in the coming years. Our understanding of this crisis is now clear, and world leaders have pledged to avert it. Nonetheless, global goals to reduce the rate of biodiversity loss have mostly not been achieved. However, many examples of conservation success show that losses can be halted and even reversed. Building on these lessons to turn the tide of biodiversity loss will require bold and innovative action to transform historical relationships between human populations and nature.

Hibernation is an important energy- and water-conserving strategy in many endotherms. Global warming is changing species’ phenology and hibernation patterns, but whether such changes are beneficial or harmful depends on the species’ life-history traits, physiology, morphology and behaviour. Mechanistic niche models can be used to make strong inferences on such responses by explicitly quantifying the consequences of changed hibernation patterns for energy and water requirements. However, they have yet to be adapted to heterothermic species. Here, we address this problem by extending the endotherm biophysical model of the NicheMapR package to capture torpor. We show how this model accurately predicts the energy requirements of hibernating animals that vary greatly in size, from microbats to bears. We then used this approach to assess the effect of climate change on the critically endangered hibernator, the mountain pygmy possum (Burramys parvus). Specifically, we contrasted conditions for the year 2010 with two future climate-change scenarios (2 °C or 4 °C of average warming) for: (i) patterns in the energetic and water requirements of hibernation and future changes; (ii) the advantage conferred by hibernating compared to not hibernating for the species’ energy and water requirements; and (iii) the areas across southeast Australia that could continue to support hibernation. We projected a 11-43% reduction in hibernation hours for the mountain pygmy possum for our two climate change scenarios compared to 2010. This increased their physiological maintenance requirements for energy (4-21%) and water (10-34%). If the possums did not hibernate at all, we calculated that they would need to consume between 77-110% more energy and 48-72% more water annually. This energetic and hydric advantage of hibernation declined with climate change. Currently occupied areas and unoccupied Tasmania were found to be the only areas in Australia suitable for hibernation under a 4° warming scenario. Our results indicate that climate change will have a profound impact on the duration and patterns of hibernation, a key survival strategy, for the mountain pygmy possum. Our framework for analysing changing hibernation patterns provides a new and general way to test the vulnerability and plasticity of hibernating endotherms facing global change.

Hibernation is an important energy- and water-conserving strategy in many endotherms. Global warming is changing species’ phenology and hibernation patterns, but whether such changes are beneficial or harmful depends on the species’ life-history traits, physiology, morphology and behaviour. Mechanistic niche models can be used to make strong inferences on such responses by explicitly quantifying the consequences of changed hibernation patterns for energy and water requirements. However, they have yet to be adapted to heterothermic species. Here, we address this problem by extending the endotherm biophysical model of the NicheMapR package to capture torpor. We show how this model accurately predicts the energy requirements of hibernating animals that vary greatly in size, from microbats to bears. We then used this approach to assess the effect of climate change on the critically endangered hibernator, the mountain pygmy possum (Burramys parvus). Specifically, we contrasted conditions for the year 2010 with two future climate-change scenarios (2 °C or 4 °C of average warming) for: (i) patterns in the energetic and water requirements of hibernation and future changes; (ii) the advantage conferred by hibernating compared to not hibernating for the species’ energy and water requirements; and (iii) the areas across southeast Australia that could continue to support hibernation. We projected a 11-43% reduction in hibernation hours for the mountain pygmy possum for our two climate change scenarios compared to 2010. This increased their physiological maintenance requirements for energy (4-21%) and water (10-34%). If the possums did not hibernate at all, we calculated that they would need to consume between 77-110% more energy and 48-72% more water annually. This energetic and hydric advantage of hibernation declined with climate change. Currently occupied areas and unoccupied Tasmania were found to be the only areas in Australia suitable for hibernation under a 4° warming scenario. Our results indicate that climate change will have a profound impact on the duration and patterns of hibernation, a key survival strategy, for the mountain pygmy possum. Our framework for analysing changing hibernation patterns provides a new and general way to test the vulnerability and plasticity of hibernating endotherms facing global change.

Large vertebrates affect fire regimes in several ways: by consuming plant matter that would otherwise accumulate as fuel; by controlling and varying the density of vegetation; and by engineering the soil and litter layer. These processes can regulate the frequency, intensity and extent of fire. The evidence for these effects is strongest in environments with intermediate rainfall, warm temperatures and graminoid-dominated ground vegetation. Probably, extinction of Quaternary megafauna triggered increased biomass burning in many such environments. Recent and continuing declines of large vertebrates are likely to be significant contributors to changes in fire regimes and vegetation that are currently being experienced in many parts of the world. To date, rewilding projects that aim to restore large herbivores have paid little attention to the value of large animals in moderating fire regimes. Rewilding potentially offers a powerful tool for managing the risks of wildfire and its impacts on natural and human values. This article is part of the theme issue ‘Trophic rewilding: consequences for ecosystems under global change’.