AIM: Physiological traits that approximate the fundamental climatic niche – the climatic conditions where a species can survive – are the outcome of adaptation to the environment under historical and ...current environmental constraints. If a large amount of the variation in physiological traits among species can be explained by their phylogeny rather than by contemporary environmental conditions, this would indicate phylogenetic conservatism in physiological traits, i.e. the tendency of species to retain their ancestral physiology over time. Here, we evaluate the relative contributions of phylogeny and environment to explain the variation in physiological traits of birds and mammals at the global level, as well as separately for tropical versus temperate species. LOCATION: Global. METHODS: We compiled a large data set from the literature, on the thermal traits and basal metabolic rates of 552 endotherms (255 bird and 297 mammal species) as measured in physiological experiments, along with phylogenetic, geographical and climatic data. Our analyses, which were performed separately for birds and mammals, partitioned the variation in comparative physiological data into the relative contributions of phylogenetic and environmental distance matrices. RESULTS: Overall, the current environment explained a larger amount of variation in thermal traits among species than the phylogeny. However, we found that phylogeny was much more important than current environment for explaining the variation in physiological traits in the tropics, whereas environment was more important than phylogeny in temperate species. MAIN CONCLUSIONS: While evidence for phylogenetic conservatism in physiological traits at the global level was weak, results for tropical species suggest phylogenetic conservatism in their physiological traits. These results indicate a stronger tendency in tropical species to retain their ancestral thermal traits, which might in turn imply a lower physiological adaptability of tropical species to ongoing and future climate change.
The extent to which different kinds of organisms have adapted to environmental temperature regimes is central to understanding how they respond to climate change. The Scholander–Irving (S-I) model of ...heat transfer lays the foundation for explaining how endothermic birds and mammals maintain their high, relatively constant body temperatures in the face of wide variation in environmental temperature. The S-I model shows how body temperature is regulated by balancing the rates of heat production and heat loss. Both rates scale with body size, suggesting that larger animals should be better adapted to cold environments than smaller animals, and vice versa. However, the global distributions of ∼9,000 species of terrestrial birds and mammals show that the entire range of body sizes occurs in nearly all climatic regimes. Using physiological and environmental temperature data for 211 bird and 178 mammal species, we test for mass-independent adaptive changes in two key parameters of the S-I model: basal metabolic rate (BMR) and thermal conductance. We derive an axis of thermal adaptation that is independent of body size, extends the S-I model, and highlights interactions among physiological and morphological traits that allow endotherms to persist in a wide range of temperatures. Our macrophysiological and macroecological analyses support our predictions that shifts inBMRand thermal conductance confer important adaptations to environmental temperature in both birds and mammals.
Metabolic critical temperatures define the range of ambient temperatures where endotherms are able to minimize energy allocation to thermogenesis. Examining the relationship between metabolic ...critical temperatures and basal metabolic rates (BMR) provides a unique opportunity to gain a better understanding of how animals respond to varying ambient climatic conditions, especially in times of ongoing and projected future climate change. We make use of this opportunity by testing the heat dissipation limit (HDL) theory, which hypothesizes that the maximum amount of heat a species can dissipate constrains its energetics. Specifically, we test the theory's implicit prediction that BMR should be lower under higher metabolic critical temperatures. We analysed the relationship of BMR with upper and lower critical temperatures for a large dataset of 146 endotherm species using regression analyses, carefully accounting for phylogenetic relationships and body mass. We show that metabolic critical temperatures are negatively related with BMR in both birds and mammals. Our results confirm the predictions of the HDL theory, suggesting that metabolic critical temperatures and basal metabolic rates respond in concert to ambient climatic conditions. This implies that heat dissipation capacities of endotherms may be an important factor to take into account in assessments of species' vulnerability to climate change.
Evaluating the impact of future changes in land-use and climate on species communities, especially species richness, is one of the most important challenges of current research in ecology and ...conservation. The impact of environmental changes on species richness depends on its sensitivity (
i.e
., how strongly a given level of change influences the ecological community) and its exposure (
i.e
., the amount of change that occurs). To examine the sensitivity, exposure, and potential impact of future environmental conditions on bird communities, we compiled data on bird species richness for Pakistan—a neglected region in macro- or country-scale studies. Since bird species richness strongly varies across seasons due to the seasonal occurrence of migratory species in winter, we compared both wintering (migratory plus resident species) and breeding (resident species only) bird richness. We found breeding and wintering species richness to be sensitive to temperature, precipitation and rainfed cropland by being positively related to these factors. Exposure varied regionally, with projected temperature changes being most profound in northern regions while the strongest projected precipitation changes occurred in central and southern regions. The projected impact of future environmental change were highly heterogeneous across the country and differed between the wintering and breeding communities. Overall, the most negatively impacted region was projected to be the Khyber Pakhtunkha province in the North of Pakistan, due to reductions in precipitation and rainfed cropland, resulting in a projected negative impact, especially on wintering species richness. By highlighting the regional and seasonal bird communities most at risk, our findings provide useful information for policy makers to help devise new policies for mitigating negative impacts of future environmental changes on birds within Pakistan.
What's on the horizon for macroecology? Beck, Jan; Ballesteros-Mejia, Liliana; Buchmann, Carsten M. ...
Ecography (Copenhagen),
August 2012, Letnik:
35, Številka:
8
Journal Article
Recenzirano
Odprti dostop
Over the last two decades, macroecology — the analysis of large-scale, multi-species ecological patterns and processes — has established itself as a major line of biological research. Analyses of ...statistical links between environmental variables and biotic responses have long and successfully been employed as a main approach, but new developments are due to be utilized. Scanning the horizon of macroecology, we identified four challenges that will probably play a major role in the future. We support our claims by examples and bibliographic analyses. 1) Integrating the past into macroecological analyses, e.g. by using paleontological or phylogenetic information or by applying methods from historical biogeography, will sharpen our understanding of the underlying reasons for contemporary patterns. 2) Explicit consideration of the local processes that lead to the observed larger-scale patterns is necessary to understand the fine-grain variability found in nature, and will enable better prediction of future patterns (e.g. under environmental change conditions). 3) Macroecology is dependent on large-scale, high quality data from a broad spectrum of taxa and regions. More available data sources need to be tapped and new, small-grain large-extent data need to be collected. 4) Although macroecology already lead to mainstreaming cutting-edge statistical analysis techniques, we find that more sophisticated methods are needed to account for the biases inherent to sampling at large scale. Bayesian methods may be particularly suitable to address these challenges. To continue the vigorous development of the macroecological research agenda, it is time to address these challenges and to avoid becoming too complacent with current achievements.
Aim We analysed latitudinal range, centres of distribution and northern range boundaries of dragonflies and damselflies occurring in Europe and North America with respect to larval habitat (standing ...water = lentic and running water = lotic). As lentic water bodies are thought to be less predictable in space and time than lotic habitats, species adapted to standing waters depend on effective dispersal ability for long-term survival. If species occurring in lentic habitats have a higher propensity for dispersal, then larger range sizes in lentic than in lotic species, as well as an increase in the proportion of lentic species with latitude, would be expected. Location Europe, North America. Methods Distributional and habitat data were collected from published sources for all odonates of Europe and North America. Species were assigned to lentic and lotic habitats according to the habitat of the larvae. From distribution maps we estimated the latitudinal range, centre of distribution and northern range boundary of each species. Differences in these distribution variables between lentic and lotic species were evaluated using ANOVA. We related the proportion of lentic species by latitudinal interval in Europe, and by political unit (state, province) in North America, to area, altitudinal range, longitude (only for North America) and latitude by means of generalized linear models. Results Lentic damselflies and dragonflies had larger latitudinal spans, and more northern distribution centres and range boundaries, than lotic species. The proportion of lentic species increased with latitude. These findings were consistent between continents. Main conclusions Our results support previous findings that distribution patterns of freshwater species depend on habitat preference. Evolution of dispersal propensity according to habitat characteristics is the most likely explanation. However, at present, alternative explanations, such as an increase in lentic habitats with latitude, cannot be ruled out.
AIM: Species distribution modelling (SDM) is commonly used to predict spatial patterns of biodiversity across sets of taxa with sufficient distributional records, while omitting narrow‐ranging ...species due to statistical constraints. We investigate the implications of this dichotomy for conservation priority setting in Africa, now and in the future. LOCATION: Sub‐Saharan Africa (excluding islands). METHODS: We use multivariate ordination to characterize climatic niches of 733 African amphibians, distinguishing between species eligible for large‐scale correlative SDM (≥ 10 records at 1° resolution) and those omitted due to insufficient records. Species distributions are projected under current and future climates using simple niche envelopes. Empirical priorities are derived separately on the eligible and omitted sets and compared with three existing large‐scale conservation schemes. RESULTS: Of the 733 amphibian species, 400 have too few records for correlative SDM, including 92% of those threatened with extinction (VU/EN/CR). Omitted species typically occupy topographically complex areas with cooler, wetter and less seasonal climates, which are projected to experience lower rates of climatic change. Priorities derived from omitted species have greater congruence with existing conservation schemes. Under future climate, priorities for eligible species shift towards those for omitted species. Similarly, while omitted species often lose climate space at 1° resolution, persistent populations tend to coincide with existing conservation schemes. MAIN CONCLUSIONS: Under current climate, statistical restrictions on SDM systematically downplay important sites for narrow‐ranging and threatened species. This issue spans taxonomic groups and is only partially mitigated by modelling at finer scales. Effective biodiversity conservation, now and in the future, relies on our capacity to project geographic determinants of all species, and thus, a wider range of approaches is essential. We conclude, however, that future persistence among narrow‐ and wide‐ranging species alike will be highest within sites already identified for conservation investment and that the focus on these sites ought to be maintained.
The digitalization of metrology poses a challenge to all members of the metrology community. We propose an approach for digital calibration certificates (DCCs) based on a PDF/A-3 solution that could ...be a stepping-stone towards the digitalization of metrological services. We present multiple applications of this approach by fulfilling discussed minimum requirements and satisfying needs from both customers and laboratories.
"An IPCC for biodiversity" – this is what many people were hoping for when the Intergovernmental Platform for Biodiversity and Ecosystem Services (IPBES) was founded. IPBES has had a very promising ...start – with a comprehensive conceptual framework and an ambitious work program. Its first published thematic assessment on pollinators, pollination and food production received wide attention within the scientific community and far beyond; the uptake by decision makers at national and regional levels has been impressive. However, during its last plenary session in March 2017, IPBES was confronted with difficult decisions due to insufficient financial pledges to the Platform’s Voluntary Trust Fund. Here, we discuss the potential consequences of the budget cuts as well as other challenges IPBES is facing, such as in facilitating stakeholder engagement. We encourage all biogeographers and other biodiversity scientists to engage in the IPBES process - to give IPBES a chance to flourish and thereby to give biodiversity an opportunity to remain on the global political agenda.
Aim
Until recently, complete information on global reptile distributions has not been widely available. Here, we provide the first comprehensive climate impact assessment for reptiles on a global ...scale.
Location
Global, excluding Antarctica.
Time period
1995, 2050 and 2080.
Major taxa studied
Reptiles.
Methods
We modelled the distribution of 6296 reptile species and assessed potential global and realm‐specific changes in species richness, the change in global species richness across climate space, and species‐specific changes in range extent, overlap and position under future climate change. To assess the future climatic impact on 3768 range‐restricted species, which could not be modelled, we compared the future change in climatic conditions between both modelled and non‐modelled species.
Results
Reptile richness was projected to decline significantly over time, globally but also for most zoogeographical realms, with the greatest decreases in Brazil, Australia and South Africa. Species richness was highest in warm and moist regions, with these regions being projected to shift further towards climate extremes in the future. Range extents were projected to decline considerably in the future, with a low overlap between current and future ranges. Shifts in range centroids differed among realms and taxa, with a dominant global poleward shift. Non‐modelled species were significantly stronger affected by projected climatic changes than modelled species.
Main conclusions
With ongoing future climate change, reptile richness is likely to decrease significantly across most parts of the world. This effect, in addition to considerable impacts on species range extent, overlap and position, was visible across lizards, snakes and turtles alike. Together with other anthropogenic impacts, such as habitat loss and harvesting of species, this is a cause for concern. Given the historical lack of global reptile distributions, this calls for a re‐assessment of global reptile conservation efforts, with a specific focus on anticipated future climate change.
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