Global changes in response to human encroachment into natural habitats and carbon emissions are driving the biodiversity extinction crisis and increasing disease emergence risk. Host distributions are one critical component to identify areas at risk of viral spillover, and bats act as reservoirs of diverse viruses. We developed a reproducible ecological niche modelling pipeline for bat hosts of SARS-like viruses (subgenus Sarbecovirus ), given that several closely related viruses have been discovered and sarbecovirus–host interactions have gained attention since SARS-CoV-2 emergence. We assessed sampling biases and modelled current distributions of bats based on climate and landscape relationships and project future scenarios for host hotspots. The most important predictors of species distributions were temperature seasonality and cave availability. We identified concentrated host hotspots in Myanmar and projected range contractions for most species by 2100. Our projections indicate hotspots will shift east in Southeast Asia in locations greater than 2°C hotter in a fossil-fuelled development future. Hotspot shifts have implications for conservation and public health, as loss of population connectivity can lead to local extinctions, and remaining hotspots may concentrate near human populations.
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Future of the human climate niche
All species have an environmental niche, and despite technological advances, humans are unlikely to be an exception. Here, we demonstrate that for millennia, human populations have resided in the same narrow part of the climatic envelope available on the globe, characterized by a major mode around ∼11 °C to 15 °C mean annual temperature (MAT). Supporting the fundamental nature of this temperature niche, current production of crops and livestock is largely limited to the same conditions, and the same optimum has been found for agricultural and nonagricultural economic output of countries through analyses of year-to-year variation. We show that in a business-as-usual climate change scenario, the geographical position of this temperature niche is projected to shift more over the coming 50 y than it has moved since 6000 BP. Populations will not simply track the shifting climate, as adaptation in situ may address some of the challenges, and many other factors affect decisions to migrate. Nevertheless, in the absence of migration, one third of the global population is projected to experience a MAT >29 °C currently found in only 0.8% of the Earth’s land surface, mostly concentrated in the Sahara. As the potentially most affected regions are among the poorest in the world, where adaptive capacity is low, enhancing human development in those areas should be a priority alongside climate mitigation.
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- Award ID(s):
- 1637171
- NSF-PAR ID:
- 10170263
- Date Published:
- Journal Name:
- Proceedings of the National Academy of Sciences
- Volume:
- 117
- Issue:
- 21
- ISSN:
- 0027-8424
- Page Range / eLocation ID:
- 11350 to 11355
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Biological invasions are usually examined in the context of their impacts on native species. However, few studies have examined the dynamics between invaders when multiple exotic species successfully coexist in a novel environment. Yet, long‐term coexistence of now established exotic species has been observed in North American lady beetle communities. Exotic lady beetles
Harmonia axyridis andCoccinella septempunctata were introduced for biological control in agricultural systems and have since become dominant species within these communities. In this study, we investigated coexistence via spatial and temporal niche partitioning amongH. axyridis andC. septempunctata using a 31‐year data set from southwestern Michigan, USA. We found evidence of long‐term coexistence through a combination of small‐scale environmental, habitat, and seasonal mechanisms. Across years,H. axyridis andC. septempunctata experienced patterns of cyclical dominance likely related to yearly variation in temperature and precipitation. Within years, populations ofC. septempunctata peaked early in the growing season at 550 degree days, whileH. axyridis populations grew in the season until 1250 degree days and continued to have high activity after this point.C. septempunctata was generally most abundant in herbaceous crops, whereasH. axyridis did not display strong habitat preferences. These findings suggest that within this regionH. axyridis has broader habitat and abiotic environmental preferences, whereasC. septempunctata thrives under more specific ecological conditions. These ecological differences have contributed to the continued coexistence of these two invaders. Understanding the mechanisms that allow for the coexistence of dominant exotic species contributes to native biodiversity conservation management of invaded ecosystems. -
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Premise The functional significance of leaf margins has long been debated. In this study, we explore influences of climate, leaf lobing, woodiness, and shared evolutionary history on two leaf margin traits within the genus
Pelargonium .Methods Leaves from 454 populations of
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MAT ), but often in patterns opposite those previously reported: species were more likely to be toothed with warmer temperatures, particularly for unlobed and highly lobed leaves. In contrast, tooth density was best predicted by the interaction ofMAT and the season of most rain; density declines with temperature as consistent with expectations, but only in winter‐rain dominated areas. Woody and nonwoody species withinPelargonium have similar associations between tooth presence/absence andMAT , contrary to the expectation that patterns within nonwoody species would be insignificant.Conclusions We conclude
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1073/pnas.1910114117
