This study investigates alpine ‘vegetation line' (the upper limit of continuous plant community) dynamics in the Himalayan alpine zone (HAZ) over a 24‐year timescale (1999–2022) using maximum NDVI products derived from Landsat series datasets, adjusted for sampling bias using phenological modelling. Vegetation line elevations across six regions spanning from Ladakh in the west to Bhutan in the east were analysed for temporal dynamics, spatial patterns of elevation and greening/browning trends (i.e. temporal increase or decrease in NDVI). Results revealed consistent upward shifts in vegetation lines across all regions, with rates ranging from 1.42 m year –1 in Khumbu (Nepal) to 6.95 m year –1 in Manthang (central High Mountain Asia). Initial levels of vegetation greenness generally increased from west to east. Across all study regions, greening trends were more prevalent than browning trends, while significant browning trends were observed in more easterly regions, specifically in Khumbu and Bhutan. Integration with the ERA5 dataset suggests snow depth as a key driver associated with the upward migration of vegetation lines, while variations in precipitation appear linked to the extent and intensity of browning. This study is the first to demonstrate vegetation line shifting patterns across the Himalayas at a 30 m spatial resolution, providing robust evidence of upward vegetation line movement under climate change and exploring underlying climatic trends.

Migration is challenging for birds, especially juveniles, who experience high mortality rates during migration. The challenge is exacerbated in the Anthropocene, contributing to widespread population declines. Conservation efforts focused on increasing juvenile survival could bolster population recovery. Understanding how age structure of the migrant community shifts throughout migration could inform conservation efforts and future questions of migration ecology. However, it is unknown whether the age structure of the migrant community shifts spatially or temporally during migration. To answer these questions, we first analyzed age‐related differences in migration speed and timing of departure during fall migration using 6 567 747 banding encounters, as variability in these components of migration could generate shifts in community demographics. We found widespread differences in migration speed (km d −1 ) with adults being faster than juveniles in most species, and departure timing differences tied to adult molt. Our analyses revealed shifts in community demographics, with the proportion of juveniles within the community decreasing at northerly latitudes throughout migration. We also determined that demographics have shifted over 53 years, with the proportion of juveniles increasing in the north, and decreasing in the south. Our findings contribute to our knowledge of migration ecology, and our understanding of community shifts over time.

The spatial ecology of stalk‐and‐ambush predators like the Eurasian lynx Lynx lynx depends on prey availability and environmental features, yet the relative roles of these factors remain unclear at large spatial scales. In this study, we analysed lynx habitat use across central and southern Finland using snow‐track data from the Wildlife Triangle Scheme (2016–2020) and a joint species distribution modelling framework (HMSC) to assess both environmental drivers and spatial predator–prey associations. The Finnish lynx population offers a unique opportunity to study a contiguous population with stark regional differences in prey availability, enabling inferences about environmental and prey effects on space use. Across the study area, lynx habitat use was primarily associated with structurally complex forests and terrain, as expected for a stalk‑and‑ambush predator. Overall, environmental conditions explained habitat use patterns to a greater degree in the central region than in the south, which we posit is due to differences between the regions in prey species. In the central region, habitat use by lynx and its prey, the mountain hare Lepus timidus , was similar, in contrast to the southern region, where lynx were spatially associated with roe deer Capreolus capreolus and white‐tailed deer Odocoileus virginianus , both of which showed habitat use patterns differing from those of lynx. These results indicate that lynx adjust their space use according to prey availability, while still retaining a core preference for complex habitat, as expected for a stalk‐and‐ambush predator. Our results are a clear demonstration of how the interplay between environmental conditions and community composition of prey shapes a generalist predator's habitat use and how this can contribute to overall resilience at the population level. Our study captures insights into habitat use at the landscape scale across contrasting ecological contexts, with implications for the management and conservation of large carnivores in human‐modified environments.

Climate change has widespread effects on the distribution, abundance and behavior of species around the world, leading to the reshuffling of ecological communities. However, it remains unclear whether individual species' range shifts scale up to result in communities whose rate of change lag, lead, or track the rate of climate change. We capitalized on a century‐old dataset originally collected by Joseph Grinnell and his students, plus modern resurveys, to measure long‐term compositional responses of small mammal communities to climate change in historical and modern eras across three regions in the Sierra Nevada of California (Lassen, Yosemite, Sequoia and Kings Canyon National Parks). Across this period, mean annual temperature in each region increased and mean annual precipitation decreased. We tested whether small mammal communities have shifted their composition in favor of species more adapted to hot and dry conditions, processes known as thermophilization and negative mesophilization, respectively. We found positive thermophilization rates (communities composed of more warm‐adapted species) in one of three regions, and negative mesophilization rates (communities composed of dry‐adapted species) in one of the three regions. We show that region‐specific colonization and extinction dynamics of warm‐, cool‐, wet‐ and dry‐adapted species jointly drive thermophilization and mesophilization rates, highlighting that community change arises from both species gains and losses. Importantly, thermophilization and mesophilization rates within regions lagged behind corresponding rates of climate change on average by 0.39–1.40°C and 154–301 mm. Our results suggest that the net effects of climate change can be directional at the scale of the ecological community, despite variability in individual species responses to environmental change and the varied mechanisms that govern them. Communities, like many individual species, may already be out of equilibrium with ambient climate.

Climate change is significantly affecting biodiversity, and organisms that depend on external temperature – such as ectotherms – are particularly vulnerable to these effects. Microhabitats provide refuge for species, thereby reducing exposure to thermal and hydric stress under climate change. Using a mechanistic modelling approach, we assessed how microhabitat variability and physiological traits influence activity behaviour, time spent in preferred temperature, shade selection, and water loss under different climate change scenarios on two green lizard species. We classified study area microhabitats using high‐resolution geospatial data and applied biophysical models to simulate organismal responses under current and future climate change scenarios (+2°C and +4°C). We first calibrated microhabitat‐specific microclimate models using field data and adjusting key parameters that determine surface energy balance and soil heat transfer, including surface roughness height, substrate longwave emissivity, and soil density. We then performed steady‐state ectotherm models and extracted physiological responses such as foraging and basking times, times spent in preferred temperature, selected shade, and water loss under current and projected climate scenarios. Our results revealed differences between species in terms of thermoregulatory and water‐loss dynamics: Timon lepidus showed higher foraging and basking activity, particularly in open rocky microhabitats. In contrast, Lacerta schreiberi relied more on shaded vegetated microhabitats and exhibited higher size‐corrected evaporative water loss. Foraging activity in T. lepidus increased in low‐slope areas, whereas L. schreiberi foraged more in steeper microhabitats, where both species also selected greater shade. Activity increased on south/west slopes, while shade selection was greater on north/west slopes. Activity periods may increase under warming conditions, but this may come at the cost of higher selected shade and water loss. These results go beyond recognizing the buffering role of microhabitats in climate change, by linking fine‐scale thermal and hydric variation to physiological strategies of lizard species. By integrating microclimate and ectotherm models, our work illustrates how species‐specific traits interact with microhabitat heterogeneity to shape differential vulnerability under warming conditions.

To better understand the dynamics of community resilience, it is crucial to examine the role of dominant species in maintaining ecosystem functions. Dominant species, due to their high abundance, are considered to maintain productivity after species loss. However, it remains unclear whether the community productivity can be maintained or restored by the remaining co‐dominant species after the loss of the dominant species. Therefore, we hypothesized that after the loss of dominant species, the lost productivity would be maintained by the co‐dominant species in the remaining community. This study, conducted over 13 years in an alpine grassland, investigates the compensatory responses of remaining species following the removal of each of two dominant species, Kobresia pygmaea (sedge) and Stipa purpurea (grass), both individually and in combination, under two nitrogen level scenarios. We found that while partial compensation (compensation index < 1) occurred in the remaining community, neither of the remaining dominant species effectively compensated for the loss of the removed species. Leguminous plants showed the most obvious positive response to the removal of dominant species, whereas forbs and sedges showed the most marked negative responses. In addition, fertilization does not promote the recovery of community productivity following removal of the dominant species. Our findings underscore the critical role of dominant species in sustaining productivity. In the face of the accelerating crisis of biodiversity extinction, priority should be given to protecting the dominant species and key functional groups in the region.

Protection targets for addressing biodiversity loss include protecting at least 30% of the land and ocean in ecologically representative areas, but do not specify how many or what proportion of species should be protected from extinction. Here, a systematic analysis of 77 880 marine, freshwater and terrestrial species indicates that all species could be protected in 50% of the planet; 69% in 30%; and 58% in 10%. These percentages only apply if the optimal areas for these species are protected. Thus, the ‘at least 30% by 2030' international target cannot protect more than about two‐thirds of all species even in these optimal places, but 50% could. However, over 80% of the species most endangered by extinction could be protected in 10% of the area. Furthermore, 39% of the optimal areas are in places with minimal human impact. Thus, focusing on these optimal places, in a network of protected areas selected to collectively include as many species as possible, would be a better target for conservation than a simple indicator of area protected.

Many indices based on presence‐absence data that compare two communities have been proposed, with the aim to characterize community similarity, species turnover or beta‐diversity, as well as other phenomena like community nestedness. These indices are often mathematically convertible to each other and are thus equivalent in terms of their information content. Based on this information equivalence, we classified all the indices to a few families, showing that only three families reflect ecologically relevant and directly interpretable phenomena, namely species turnover (family of Jaccard index that also includes Sørensen index of similarity), nestedness (the family of indices which compare species overlap with species richness of the species‐poor community), and the uniformity of species richness (comparing species richness of the two communities). Importantly, our analysis shows that any attempt to partition indices, including Baselga's approach to partition turnover and nestedness (i.e. to control an index for an effect of a different phenomenon), leads either to an index belonging to one of the three abovementioned families, or produces indices that do not measure any ecologically relevant phenomenon. We provide guidance on how to apply pairwise indices to make proper inference about ecological phenomena.

Escalating wildfire frequency and severity are altering wildland habitats worldwide. Yet investigations into fire impacts on wildlife habitat rarely extend to the macroecological scales relevant to species conservation and global change processes. We evaluate the effects of wildfire on habitat quality and selection by large mammals spanning three trophic levels in the Western United States. We analyze 12 years of GPS telemetry data for 2966 mule deer Odocoileus hemionus , 52 black bears Ursus americanus , and 74 cougars Puma concolor across Utah and Nevada, USA. Over 800 areas burned between 1990–2022 overlapped with the home ranges of 1892 animals, resulting in almost 23 000 km 2 of burned habitat and representing 12.8% of the total home range area for animals in our sample. Habitat suitability models for 664 mule deer, 14 black bears and 11 cougars indicated that burns improved summer home range quality for mule deer and black bears by 7% and 14%, respectively, highlighting the benefits of fires for nutrient cycling, understory herbaceous growth, and resultant caloric value for animal nutrition. When making fine‐scale movement decisions, however, mule deer avoided burned habitats, and all three species generally avoided high‐severity burns for up to 30 years post‐fire. Thus, the effects of burns on wildlife habitat selection appear to be dependent on spatial scale. Given projected increases in large, severe fires, our results suggest potential reductions in beneficial habitat for wildlife in the long term. However, our results also suggest that prescribed burns, because of their smaller spatial footprints and lower severity relative to wildfires, can benefit wildlife habitat quality through improvements in forage, cover, and other vegetation characteristics. Therefore, managing for low‐severity burns and limiting large, severe wildfires, e.g. via prescribed burns or fire control policies, could positively impact the habitat quality of these three common species and, therefore, the economic and ecosystem services they provide.