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Rapid climate change is impacting biodiversity, ecosystem function, and human well‐being. Though the magnitude and trajectory of climate change are becoming clearer, our understanding of how these changes reshape terrestrial life zones—distinct biogeographic units characterized by biotemperature, precipitation, and aridity representing broad‐scale ecosystem types—is limited. To address this gap, we used high‐resolution historical climatologies and climate projections to determine the global distribution of historical (1901–1920), contemporary (1979–2013), and future (2061–2080) life zones. Comparing the historical and contemporary distributions shows that changes from one life zone to another during the 20th century impacted 27 million km2 (18.3% of land), with consequences for social and ecological systems. Such changes took place in all biomes, most notably in Boreal Forests, Temperate Coniferous Forests, and Tropical Coniferous Forests. Comparing the contemporary and future life zone distributions shows the pace of life zone changes accelerating rapidly in the 21st century. By 2070, such changes would impact an additional 62 million km2 (42.6% of land) under "business‐as‐usual" (RCP8.5) emissions scenarios. Accelerated rates of change are observed in hundreds of ecoregions across all biomes except Tropical Coniferous Forests. While only 30 ecoregions (3.5%) had over half of their areas change to a different life zone during the 20th century, by 2070 this number is projected to climb to 111 ecoregions (13.1%) under RCP4.5 and 281 ecoregions (33.2%) under RCP8.5. We identified weak correlations between life zone change and threatened vertebrate richness, levels of vertebrate endemism, cropland extent, and human population densities within ecoregions, illustrating the ubiquitous risks of life zone changes to diverse social–ecological systems. The accelerated pace of life zone changes will increasingly challenge adaptive conservation and sustainable development strategies that incorrectly assume current ecological patterns and livelihood provisioning systems will persist. [ABSTRACT FROM AUTHOR]

Environmental heterogeneity enhances species richness by creating niches and providing refugia. Spatial variation in climate has a particularly strong positive correlation with richness, but is often indirectly inferred from proxy variables, such as elevation and related topographic heterogeneity indices, or derived from interpolated coarse‐grain weather station data. Our aim was to develop new remotely sensed metrics of relative temperature and thermal heterogeneity, compare them with proxy measures, and evaluate their performance in predicting species richness patterns. We analyzed Landsat 8's Thermal Infrared Sensor data, calculated two thermal metrics during summer and winter, and compared their seasonal spatial patterns with those of elevation and topographic heterogeneity. We fit generalized least squares models to evaluate each variable's effect in predicting seasonal bird richness using data from the North American Breeding Bird Survey. Generally speaking, neither elevation nor topographic heterogeneity were good proxies for temperature or thermal heterogeneity, respectively. Relative temperature had a non‐linear relationship with elevation that was negatively quadratic in summer, but slightly positively quadratic in winter. Topographic heterogeneity had a stronger positive relationship with thermal heterogeneity in winter than in summer. The magnitude and direction of elevation–temperature and topographic heterogeneity–thermal heterogeneity relationships in each season also varied substantially across ecoregions. Remotely sensed metrics of relative temperature and thermal heterogeneity improved the predictive performance of species richness models, and both thermal variables had significant effects on bird richness that were independent of elevation and topographic heterogeneity. Thermal heterogeneity was positively related to total breeding bird richness, migrant breeding bird richness and resident bird richness, whereas topographic heterogeneity was negatively related to total breeding richness and unrelated to migrant or resident bird richness. Because thermal and topographic heterogeneity had contrasting seasonal patterns and effects on richness, they must be carefully contextualized when guiding conservation priorities. [ABSTRACT FROM AUTHOR]

The article discusses about the adoption of mitigation policies, adaptation policies that improve the complementarity of climatic conditions within protected areas (PAs) will help countries safeguard biodiversity. It mentions that the PAs as essential to biodiversity conservation, but their static boundaries may undermine their potential for protecting species under climate change.

Understanding how and why species respond to land‐use change is one of the central challenges in conservation biology, yet the causes of variation in the responses of species to land‐use change remain unclear. We tested whether adaptation to different abiotic environments influenced the vulnerability of bird communities to agricultural expansion in the Himalayan mountain range, which exhibits a strong east–west gradient in annual temperature variation. We did so by surveying bird communities in forest and agriculture at opposite ends of that gradient. We contrasted metrics of species richness, diversity, community composition and forest dependency across land‐use types and regions, and tested whether species' thermal sensitivity influenced their response to the replacement of forest with agriculture. Agricultural land in the relatively aseasonal east harboured significantly fewer bird species than did forests, a pattern that is starkly reversed in the highly seasonal west. For species common to both regions, eastern populations used forest ~35% more than did western populations. While western species were less constrained by temperature than eastern species, western species with narrow thermal tolerances were also more forest dependent. Selection across a stark environmental gradient on a common species pool appears to have altered the vulnerability of Himalayan birds to forest loss, with communities in the relatively aseasonal east much more sensitive to forest conversion than those in the west. Adaptation to local environmental conditions appears to mediate species' responses to land use change, with thermal specialists more vulnerable to forest loss than species with greater thermal tolerances. Species' responses to global change may differ predictably along abiotic gradients even within a single region or biodiversity hotspot, and such variation must be addressed in conservation planning. [ABSTRACT FROM AUTHOR]

Conserving mountains is important for protecting biodiversity because they have high beta diversity and endemicity, facilitate species movement, and provide numerous ecosystem benefits for people. Mountains are often thought to have lower levels of human modification and contain more protected area than surrounding lowlands. To examine this, we compared biogeographic attributes of the largest, contiguous, mountainous region on each continent. In each region, we generated detailed ecosystems based on Köppen−Geiger climate regions, ecoregions, and detailed landforms. We quantified anthropogenic fragmentation of these ecosystems based on human modification classes of large wild areas, shared lands, and cities and farms. Human modification for half the mountainous regions approached the global average, and fragmentation reduced the ecological integrity of mountain ecosystems up to 40%. Only one‐third of the major mountainous regions currently meet the Kunming‐Montreal Global Biodiversity Framework target of 30% coverage for all protected areas; furthermore, the vast majority of ecosystem types present in mountains were underrepresented in protected areas. By measuring ecological integrity and human‐caused fragmentation with a detailed representation of mountain ecosystems, our approach facilitates tracking progress toward achieving conservation goals and better informs mountain conservation. [ABSTRACT FROM AUTHOR]

The Himalayas are a global biodiversity hotspot threatened by widespread agriculture and pasture expansion. To determine the impact of these threats on biodiversity and to formulate appropriate conservation strategies, we surveyed birds along elevational gradients in primary forest and in human‐dominated lands spanning a gradient of habitat alteration, including forest‐agriculture mosaics, mixed agriculture mosaics, and pasture. We surveyed birds during the breeding season and in winter to account for pronounced seasonal migrations. Bird abundance and richness in forest‐agriculture and mixed agriculture mosaics were equal to or greater than in primary forest and greater than in pasture at local and landscape scales during both seasons. Pasture had greater abundance and richness of birds in winter than primary forest, but richness was greater in primary forest at the landscape scale during the breeding season. All 4 land‐use types held unique species, suggesting that all must be retained in the landscape to conserve the entire avifauna. Our results suggest forest‐agriculture and mixed agriculture mosaics are particularly important for sustaining Himalayan bird communities during winter and primary forests are vital for sustaining Himalayan bird communities during the breeding season. Further conversion of forest‐agriculture and mixed agriculture mosaics to pasture would likely result in significant biodiversity losses that would disproportionately affect breeding species. To ensure comprehensive conservation, strategies in the western Himalayas must balance the protection of intact primary forest with the minimization of pasture expansion. Article impact statement: Comprehensive conservation in the Himalayas requires both protecting intact primary forest and minimizing pasture expansion [ABSTRACT FROM AUTHOR]

Protected areas (PAs) that span elevational gradients enhance protection for taxonomic and phylogenetic diversity and facilitate species range shifts under climate change. We quantified the global protection of elevational gradients by analyzing the elevational distributions of 44,155 PAs in 1,010 mountain ranges using the highest resolution digital elevation models available. We show that, on average, mountain ranges in Africa and Asia have the lowest elevational protection, ranges in Europe and South America have intermediate elevational protection, and ranges in North America and Oceania have the highest elevational protection. We use the Convention on Biological Diversity's Aichi Target 11 to assess the proportion of elevational gradients meeting the 17% suggested minimum target and examine how different protection categories contribute to elevational protection. When considering only strict PAs [International Union for Conservation of Nature (IUCN) categories I-IV, n = 24,706], nearly 40% of ranges do not contain any PAs, roughly half fail to meet the 17% target at any elevation, and ~75% fail to meet the target throughout ≥50% of the elevational gradient. Observed elevational protection is well below optimal, and frequently below a null model of elevational protection. Including less stringent PAs (IUCN categories V-VI and nondesignated PAs, n = 19,449) significantly enhances elevational protection for most continents, but several highly biodiverse ranges require new or expanded PAs to increase elevational protection. Ensuring conservation outcomes for PAs with lower IUCN designations as well as strategically placing PAs to better represent and connect elevational gradients will enhance ecological representation and facilitate species range shifts under climate change. [ABSTRACT FROM AUTHOR]

Longstanding theory predicts that competitive interactions set species' range limits in relatively aseasonal, species-rich regions, while temperature limits distributions in more seasonal, species-poor areas. More recent theory holds that species evolve narrow physiological tolerances in aseasonal regions, with temperature being an important determining factor in such zones. We tested how abiotic (temperature) and biotic (competition) factors set range limits and structure bird communities along strong, opposing, temperature-seasonality and species-richness gradients in the Himalayas, in two regions separated by 1500 km. By examining the degree to which seasonal elevational migration conserves year-round thermal niches across species, we show that species in the relatively aseasonal and speciose east are more constrained by temperature compared with species in the highly seasonal west. We further show that seasonality has a profound effect on the strength of competition between congeneric species. Competition appears to be stronger in winter, a period of resource scarcity in the Himalayas, in both the east and the west, with similarly sized eastern species more likely to segregate in thermal niche space in winter. Our results indicate that rather than acting in isolation, abiotic and biotic factors mediate each other to structure ecological communities. [ABSTRACT FROM AUTHOR]

The impacts of land-use change on biodiversity in the Himalayas are poorly known, notwithstanding widespread deforestation and agricultural intensification in this highly biodiverse region. Although intact primary forests harbor many Himalayan birds during breeding, a large number of bird species use agricultural lands during winter. We assessed how Himalayan bird species richness, abundance, and composition during winter are affected by forest loss stemming from agriculture and grazing. Bird surveys along 12 elevational transects within primary forest, low-intensity agriculture, mixed subsistence agriculture, and intensively grazed pastures in winter revealed that bird species richness and abundance were greatest in low-intensity and mixed agriculture, intermediate in grazed pastures, and lowest in primary forest at both local and landscape scales; over twice as many species and individuals were recorded in low-intensity agriculture than in primary forest. Bird communities in primary forests were distinct from those in all other land-use classes, but only 4 species were unique to primary forests. Low-, medium-, and high-intensity agriculture harbored 32 unique species. Of the species observed in primary forest, 80% had equal or greater abundance in low-intensity agricultural lands, underscoring the value of these lands in retaining diverse community assemblages at high densities in winter. Among disturbed landscapes, bird species richness and abundance declined as land-use intensity increased, especially in high-intensity pastures. Our results suggest that agricultural landscapes are important for most Himalayan bird species in winter. But agricultural intensification-especially increased grazing-will likely result in biodiversity losses. Given that forest reserves alone may inadequately conserve Himalayan birds in winter, comprehensive conservation strategies in the region must go beyond protecting intact primary forests and ensure that low-intensity agricultural lands are not extensively converted to high-intensity pastures. [ABSTRACT FROM AUTHOR]

There is clear evidence that species' ranges along environmental gradients are constrained by both biotic and abiotic factors, yet their relative importance in structuring realized distributions remains uncertain. We surveyed breeding bird communities while collecting in situ temperature and vegetation data along five elevational transects in the Himalayas differing in temperature variability, habitat zonation, and bird richness in order to disentangle temperature, habitat, and congeneric competition as mechanisms structuring elevational ranges. Our results from species' abundance models representing these three mechanisms differed markedly from previous, foundational research in the tropics. Contrary to general expectations, we found little evidence for competition as a major determinant of range boundaries, with congeneric species limiting only 12% of ranges. Instead, temperature and habitat were found to structure the majority of species' distributions, limiting 48 and 40% of ranges, respectively. Our results suggest that different mechanisms may structure species ranges in the temperate Himalayas compared to tropical systems. Despite recent evidence suggesting temperate species have broader thermal tolerances than tropical species, our findings reinforce the notion that the abiotic environment has significant control over the distributions of temperate species. [ABSTRACT FROM AUTHOR]

The thermal environment limits species ranges through its influence on physiology and resource distributions and thus affects species richness patterns over broad spatial scales. Understanding how temperature drives species richness patterns is particularly important in the context of global change and for effective conservation planning. Landsat 8's Thermal Infrared Sensor (TIRS) allows direct mapping of temperature at moderate spatial resolutions (100 m, downscaled by the USGS to 30 m), overcoming limitations inherent in coarse interpolated weather station data that poorly capture fine-scale temperature patterns over broad areas. TIRS data thus offer the unique opportunity to understand how the thermal environment influences species richness patterns. Our aim was to develop and assess the ability of TIRS-based temperature metrics to predict patterns of winter bird richness across the conterminous United States during winter, a period of marked temperature stress for birds. We used TIRS data from 2013-2018 to derive metrics of relative temperature and intra-seasonal thermal heterogeneity. To quantify winter bird richness across the conterminous US, we tabulated the richness only for resident bird species, i.e., those species that do not move between the winter and breeding seasons, from the North American Breeding Bird Survey, the most extensive survey of birds in the US. We expected that relative temperature and thermal heterogeneity would have strong positive associations with winter bird richness because colder temperatures heighten temperature stress for birds, and thermal heterogeneity is a proxy for thermal niches and potential thermal refugia that can support more species. We further expected that both the strength of the effects and the relative importance of these variables would be greater for species with greater climate sensitivity, such as small-bodied species and climate-threatened species (i.e., those with large discrepancies between their current and future distributions following projected climate change). Consistent with our predictions, relative temperature and thermal heterogeneity strongly positively influenced winter bird richness patterns, with statistical models explaining 37.3% of the variance in resident bird richness. Thermal heterogeneity was the strongest predictor of small-bodied and climate-threatened species in our models, whereas relative temperature was the strongest predictor of large-bodied and climate-stable species. Our results demonstrate the important role that the thermal environment plays in governing winter bird richness patterns and highlight the previously underappreciated role that intra-seasonal thermal heterogeneity may have in supporting high winter bird species richness. Our findings thus illustrate the exciting potential for TIRS data to guide conservation planning in an era of global change. • Landsat 8 TIRS data are used to develop two new metrics of the thermal environment. • Relative temperature and thermal heterogeneity predict winter bird richness. • Thermal variables are more important for thermally sensitive species across the US. • Thermal remote sensing data from TIRS have promise to guide conservation planning. [ABSTRACT FROM AUTHOR]

Mountain treelines are thought to be sensitive to climate change. However, how climate impacts mountain treelines is not yet fully understood as treelines may also be affected by other human activities. Here, we focus on "closed‐loop" mountain treelines (CLMT) that completely encircle a mountain and are less likely to have been influenced by human land‐use change. We detect a total length of ~916,425 km of CLMT across 243 mountain ranges globally and reveal a bimodal latitudinal distribution of treeline elevations with higher treeline elevations occurring at greater distances from the coast. Spatially, we find that temperature is the main climatic driver of treeline elevation in boreal and tropical regions, whereas precipitation drives CLMT position in temperate zones. Temporally, we show that 70% of CLMT have moved upward, with a mean shift rate of 1.2 m/year over the first decade of the 21st century. CLMT are shifting fastest in the tropics (mean of 3.1 m/year), but with greater variability. Our work provides a new mountain treeline database that isolates climate impacts from other anthropogenic pressures, and has important implications for biodiversity, natural resources, and ecosystem adaptation in a changing climate. [ABSTRACT FROM AUTHOR]

Grassland ecosystems cover up to 40% of the global land area and provide many ecosystem services directly supporting the livelihoods of over 1 billion people. Monitoring long-term changes in grasslands is crucial for food security, biodiversity conservation, achieving Land Degradation Neutrality goals, and modeling the global carbon budget. Although long-term grassland monitoring using remote sensing is extensive, it is typically based on a single vegetation index and does not account for temporal and spatial autocorrelation, which means that some trends are falsely identified while others are missed. Our goal was to analyze trends in grasslands in Eurasia, the largest continuous grassland ecosystems on Earth. To do so, we calculated Cumulative Endmember Fractions (annual sums of monthly ground cover fractions) derived from MODIS 2002-2020 time series, and applied a new statistical approach PARTS that explicitly accounts for temporal and spatial autocorrelation in trends. We examined trends in green vegetation, non-photosynthetic vegetation, and soil ground cover fractions considering their independent change trajectories and relations among fractions over time. We derived temporally uncorrelated pixel-based trend maps and statistically tested whether observed trends could be explained by elevation, land cover, SPEI3, climate, country, and their combinations, all while accounting for spatial autocorrelation. We found no statistical evidence for a decrease in vegetation cover in grasslands in Eurasia. Instead, there was a significant map-level increase in non-photosynthetic vegetation across the region and local increases in green vegetation with a concomitant decrease in soil fraction. Independent environmental variables affected trends significantly, but effects varied by region. Overall, our analyses show in a statistically robust manner that Eurasian grasslands have changed considerably over the past two decades. Our approach enhances remote sensing-based monitoring of trends in grasslands so that underlying processes can be discerned. [ABSTRACT FROM AUTHOR]

Aim: The African Guineo‐Congolian (GC) region is a global biodiversity hotspot with high species endemism, bioclimatic heterogeneity, complex landscape features, and multiple biogeographic barriers. Bioclimatic and geographic variables influence global patterns of species richness and endemism, but their relative importance varies across taxa and regions and is poorly understood for many faunas. Here, we test the hypothesis that turnover in endemic amphibians of the GC biodiversity hotspot is influenced mainly by the geographic distance between grid cells and secondarily by rainfall‐ and temperature‐related variables. Location: West and Central Africa. Major Taxa Studied: Amphibians. Methods: We compiled species‐occurrence records via field sampling, online databases, and taxonomic literature. Our study used 1205 unique georeferenced records of 222 amphibian species endemic to the GC region. Patterns of species richness were mapped onto a grid with a spatial resolution of 0.5° × 0.5°. We estimated weighted endemism and tested whether endemism was higher than the expected species richness (randomization test). We quantified species turnover using generalized dissimilarity modelling to evaluate the processes underlying observed patterns of species richness in GC endemic amphibians. We explored bioregionalization using agglomerative hierarchical clustering based on the unweighted pair group method with arithmetic averages. Results: We identified seven areas within the lower GC region – forests in Cameroon, Gabon, Southern Nigeria, Equatorial Guinea, Republic of Congo, Democratic Republic of Congo, and Cote d'Ivoire – as having high species richness of endemic amphibians. The randomization test returned four major areas of significant weighted endemism: Nigeria‐Cameroon mountains, forest regions of the Democratic Republic of Congo, Cote d'Ivoire, and Ghana. Our analysis revealed five bioregions for amphibian endemism, four of which were located within the lower Guineo‐Congolian forest. Species turnover was strongly related to the geographic distance between grid cells; contributing bioclimatic variables included precipitation of the warmest quarter, mean temperature of the wettest quarter, and mean diurnal temperature range. Main Conclusions: Our results indicate that geographic distance between grid cells is the primary determinant of turnover in GC endemic amphibians, with secondary but significant effects of rainfall‐ and temperature‐related variables. Our study identifies key areas of endemic amphibian richness that could be prioritized for conservation actions. [ABSTRACT FROM AUTHOR]

Incentivizing carbon storage can be a win-win pathway to conserving biodiversity and mitigating climate change. In savannas, however, the situation is more complex. Promoting carbon storage through woody encroachment may reduce plant diversity of savanna endemics, even as the diversity of encroaching forest species increases. This trade-off has important implications for the management of biodiversity and carbon in savanna habitats, but has rarely been evaluated empirically. We quantified the nature of carbon-diversity relationships in the Brazilian Cerrado by analyzing how woody plant species richness changed with carbon storage in 206 sites across the 2.2 million km2 region at two spatial scales. We show that total woody plant species diversity increases with carbon storage, as expected, but that the richness of endemic savanna woody plant species declines with carbon storage both at the local scale, as woody biomass accumulates within plots, and at the landscape scale, as forest replaces savanna. The sharpest trade-offs between carbon storage and savanna diversity occurred at the early stages of carbon accumulation at the local scale but the final stages of forest encroachment at the landscape scale. Furthermore, the loss of savanna species quickens in the final stages of forest encroachment, and beyond a point, savanna species losses outpace forest species gains with increasing carbon accumulation. Our results suggest that although woody encroachment in savanna ecosystems may provide substantial carbon benefits, it comes at the rapidly accruing cost of woody plant species adapted to the open savanna environment. Moreover, the dependence of carbon-diversity trade-offs on the amount of savanna area remaining requires land managers to carefully consider local conditions. Widespread woody encroachment in both Australian and African savannas and grasslands may present similar threats to biodiversity. [ABSTRACT FROM AUTHOR]

Over the course of a year, vegetation and temperature have strong phenological and seasonal patterns, respectively, and many species have adapted to these patterns. High inter-annual variability in the phenology of vegetation and in the seasonality of temperature pose a threat for biodiversity. However, areas with high spatial variability likely have higher ecological resilience where inter-annual variability is high, because spatial variability indicates presence of a range of resources, microclimatic refugia, and habitat conditions. The integration of inter-annual and spatial variability is thus important for biodiversity conservation. Areas where spatial variability is low and inter-annual variability is high are likely to limit resilience to disturbance. In contrast, areas of high spatial variability may be high priority candidates for protection. Our goal was to develop spatio-temporal remotely sensed indices to identify hotspots of biodiversity conservation concern. We generated indices that capture the inter-annual and spatial variability of vegetation greenness and land surface temperature and integrated them to identify areas of high, medium, and low biodiversity conservation concern. We applied our method in Argentina (2.8 million km2), a country with a wide range of climates and biomes. To generate the inter-annual variability indices, we analyzed MODIS Enhanced Vegetation Index (EVI) and Land Surface Temperature (LST) time series from 2001 to 2018, fitted curves to obtain annual phenological and seasonal metrics, and calculated their inter-annual variability. To generate the spatial variability indices, we calculated standard deviation image texture of Landsat 8 EVI and LST. When we integrated our inter-annual and spatial variability indices, areas in the northeast and parts of southern Argentina were the hotspots of highest conservation concern. High inter-annual variability poses a threat in these areas, because spatial variability is low. These are areas where management efforts could be valuable. In contrast, areas in the northwest and central-west are where protection should be strongly considered because the high spatial variability may confer resilience to disturbance, due to the variety of conditions and resources within close proximity. We developed remotely sensed indices to identify hotspots of high and low conservation concern at scales relevant to biodiversity conservation, which can be used to target management actions in order to minimize biodiversity loss. • We present novel applications of spatial and temporal indices for conservation. • We identify spatial and inter-annual variability in vegetation greenness and LST. • MODIS EVI and LST time series capture inter-annual variability. • Landsat 8 EVI and LST texture capture spatial variability. • The spatio-temporal indices identify hotspots of high and low conservation concern. [ABSTRACT FROM AUTHOR]