Habitat loss is the dominant cause of biodiversity decline around the world, yet the complexity and stability of terrestrial assemblages related to suitable habitats have been almost unknown on a global scale.
Global.
Contemporary.
Mammalia, Aves, Reptilia, Amphibia.
We constructed gridded maps of species–habitat networks of terrestrial vertebrates based on global species distributions and a recently developed habitat type dataset. Then, we investigated the biogeographic patterns of emergent network structures and analysed network robustness to habitat loss by simulating habitat removals on a global scale.
We found that, compared with reptiles and amphibians, the species–habitat networks of mammals and birds were characterised by higher habitat diversity, connectance and modularity. All four taxonomical groups have high robustness globally, but after adjusting for species and habitat diversity, we found a variation of surplus and deficiency of network structures and robustness. Temperature and precipitation contributed most to relative network robustness globally, whereas geographical and human population factors played important roles in scattered regions on all continents.
Overall, we provide novel insights into the biogeographic patterns of species–habitat connections through a network approach, which can help to identify gaps for reestablishing species–habitat links to improve conservation outcomes.
To describe worldwide distribution of mammalian cradles and museums using the rates of phylogenetic lineage turnover as a surrogate. Additionally, we investigated the influences of current water–energy dynamics, climate instability, past climate changes and elevational ranges on the distribution of these evolutionary zones.
Global.
Current.
Terrestrial mammals.
We developed a new methodology that consists of calculating the spatial phylogenetic turnover for non-overlapping temporal segments of phylogenetic trees. By calculating the relative turnover in each tree segment, we quantified the rate of accumulation of phylogenetic turnover through time. We depicted cold and hotspots of rates of lineage turnover using bivariate maps and examined the effects of environmental factors using a path model.
The distributions of cradles and museums of biodiversity are primarily driven by water–energy dynamics. Environments with higher water availability than energetic demand predominantly act as cradles, as seen in tropical rainforests, while xeric-like environments predominantly serve as museums. Conversely, regions undergoing higher historical climate changes become cradles, such as in higher northern latitudes, while climatically stable areas function as museums. Mountains play a dual role, acting as both cradles and museums by generating new lineages along their elevation bands while simultaneously providing climate refuges for ancient mammal lineages.
Our findings demonstrate that cradles and museums are not merely a dichotomy but exist along an evolutionary continuum. Furthermore, they reveal how spatial patterns of mammalian cradles and museums are intricately shaped by biogeographical processes governed by environmental forces. Uncovering these hidden effects provides insights into the ecological mechanisms by which ongoing climate changes continually shape evolutionary assemblages over time.
Species distribution models (SDMs) are powerful tools for assessing suitable habitats across large areas and at fine spatial resolution. Yet, the usefulness of SDMs for mapping species' realised distributions is often limited since data biases or missing information on dispersal barriers or biotic interactions hinder them from accurately delineating species' range limits. One way to overcome this limitation is to integrate SDMs with expert range maps, which provide coarse-scale information on the extent of species' ranges and thereby range limits that are complementary to information offered by SDMs.
Here, we propose a new approach for integrating expert range maps in SDMs based on an ensemble method called stacked generalisation. Specifically, our approach relies on training a meta-learner regression model using predictions from one or more SDM algorithms alongside the distance of training points to expert-defined ranges as predictor variables. We demonstrate our approach with an occurrence dataset for 49 bat species covering four biodiversity hotspots in the Eastern Mediterranean, Western Asia and Central Asia.
Our approach offers a flexible method to integrate expert range maps with any combination of SDM modelling algorithms, thus facilitating the use of algorithm ensembles. In addition, it provides a novel, data-driven way to account for uncertainty in expert-defined ranges not requiring prior knowledge about their accuracy, which is often lacking. Integrating expert range maps into SDMs for bats resulted in more realistic predictions of distribution patterns that showed narrower niche breadths and smaller range overlaps between species compared to traditional SDMs. Our approach holds promise to improve assessments of species distributions, while our work highlights the overlooked potential of stacked generalisation as an ensemble method in species distribution modelling.
As global climate changes, there is a clear mismatch between the temporal and spatial characteristics of body temperature and environmental temperature, confounding the assessment of thermal stress for organisms in many ecological studies. Here, we hindcast the hourly body temperatures of intertidal molluscs to explore the differences between them and environmental temperatures (air and water temperatures) in multiple metrics of thermal stress.
Intertidal shores in East Asia (0°–45°N, 100°E–140°E).
40 years, 1980 to 2019.
Mollusca.
We collected habitat zonation data and measured the morphological characteristics of 25 intertidal molluscs living in East Asia. For three different types of intertidal molluscs (i.e., bivalves, limpets and snails), we built corresponding heat budget models (HBMs) to hindcast the hourly body temperatures from 1980 to 2019. We analysed the thermal stress of intertidal species faced in three metrics, annual extreme high temperatures (T99), seasonal daily maximum temperatures (DMT) and heatwaves, and compared them with environmental temperatures.
We found that T99 of body temperatures and their interannual warming rates are significantly higher than those of environmental temperatures. Moreover, there were non-negligible mismatches between the seasonal thermal pattern and heatwaves of body temperatures and environmental temperatures, suggesting that the deleterious impacts of global warming on intertidal species are underestimated and cannot be directly revealed by environmental temperatures.
Thermal stress patterns of body temperature were significantly different from those of environmental temperature, and the thermal stress faced by intertidal species had been persistently underestimated. These results emphasise that body temperature should be used as the appropriate metric for evaluating and predicting the impacts of global warming and weather extremes in the intertidal biological system.
Terrestrial predators play key roles in cycling nutrients, as well as limiting prey populations, and shaping the behaviour of their prey. Prehistoric, historic and ongoing declines of the world's predators have reshaped terrestrial ecosystems and are a topic of conservation concern. However, the availability of ecologically relevant predator functional traits is limited, hampering efforts to understand macroecological changes in this ecologically important functional group. Here, we present CarniTraits, a comprehensive open-access functional trait database of all late Quaternary (~130,000 ybp) terrestrial mammalian predators (149 species, ≥1 kg body mass, ≥50% vertebrate meat consumption).
Mammalian terrestrial predator functional traits including body mass, diet, scavenging, locomotion, cooperative hunting, hunting habitat, hunting method, bone consumption, temporal activity patterns, brain mass and encephalisation quotient.
Global.
Late Quaternary (the last ~130,000 years).
All late Quaternary terrestrial mammalian predators (149 species, ≥1 kg body mass, ≥50% vertebrate meat consumption).
csv.
The Kunming-Montreal Global Biodiversity Framework requires that evolutionary histories of species should be considered in conservation planning. The phylogenetic structure of species assemblages quantifies species evolutionary histories and increasingly becomes an endeavour for ecologists. Understanding the geographic patterns of phylogenetic structure of species assemblages and their drivers can provide a fundamental reference for conservation planning. Although several theoretical hypotheses based on the effects of contemporary environment, historical climate change and evolutionary niche conservatism had been widely discussed in previous studies, the relative contributions of these hypotheses on phylogenetic structure of angiosperms, especially herbaceous species, remain debated.
East Eurasia.
Angiosperms.
We compiled distributions of 43,023 angiosperm species in east Eurasia at spatial resolution (100 × 100 km2). Using this newly compiled database and a species-level phylogeny, we estimated the phylogenetic structure patterns for species with different growth forms. We explored the relationships of these patterns with contemporary environment and historical climate change to test predictions of the tropical niche conservatism hypothesis (TCH) and to compare the contribution of different hypotheses using generalised linear models and hierarchical partitioning.
We found that phylogenetic structure of angiosperms displayed significant latitudinal gradients. Notably, phylogenetic structure patterns and their drivers differed between woody and herbaceous species. Actual evapotranspiration was the best predictor of phylogenetic structure patterns for all and herbaceous species, while the mean temperature of the coldest quarter was the best predictor for woody species. The effect of historical climate change on phylogenetic structure patterns was weak.
Our results suggest that the TCH only explains the phylogenetic structure pattern of woody species, not herbaceous species. Moreover, contemporary climate influences the phylogenetic structure of angiosperms in east Eurasian by affecting herbaceous and woody species differently.
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