Microbes, as the planet's most abundant and diverse organisms, drive soil functions globally and are vulnerable to environmental stressors triggered by global change. Yet, knowledge regarding the impacts of multiple environmental stressors on their functional profiles as well as the consequences for soil functionality largely remains unknown. Here, we analyze two global-scale datasets including information on soil metagenomics and multiple environmental stressors. We find that across terrestrial ecosystems worldwide, up to 60% of all functional genes significantly shift when soil microbes experience the high-level of concurrent stressors. In this regard, the relative abundances of genes involved in microbial growth are negatively linked to the increasing number of stressors. Conversely, those genes linked to stress resistance and energy production exhibit positive responses. Taken together, our findings highlight a significant restructuring of global soil functional microbiomes in response to multiple environmental stressors. Consequently, such restructuring drives community-level shifts in matter and energy reallocations, thereby impacting the maintenance of soil functionality under the projected global change.

Aridity alters soil carbon (C), nitrogen (N) and phosphorus (P) stoichiometry, yet the implications of these processes for soil microbial functional traits and potentials at the genomic level remain poorly synthesized. Here we combine measurements of soil C, N and P pools and ratios with shotgun metagenomes from 200 natural ecosystems spanning major biomes worldwide. Across sites, increased aridity is associated with lower soil C:N and N:P (and C:P) ratios and with a coordinated shift in microbial functional potential. Genes linked to catabolic resource acquisition-including carbohydrate-active enzymes and pathways for degradation of plant litter and organophosphorus compounds-are declined as C becomes relatively scarce. In contrast, genes supporting anabolic investment in growth and drought resistance, such as RNA transcription, protein synthesis and intracellular transport, are increased. These patterns indicate that aridity-related change in soil elemental ratios is coupled to a broad shift from catabolic to anabolic strategies in soil microbiomes. By linking soil elemental ratios to microbial functional traits across biomes, our study provides a framework for anticipating how climate-driven drying may reorganize microbial metabolism with consequences for carbon and nutrient cycling.

Past temperature reconstructions offer valuable insights into the impact of climate change on the global climate-human-vegetation system. Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are recognized as effective temperature proxies, particularly in lakes and peatlands, where they are well preserved. However, their reliability as palaeothermometers can be compromised by factors beyond air temperature, especially in drylands. This study investigates the recently compiled Arid Central Asian (ACA) brGDGT surface Data Base, a regional dataset consisting of 753 surface samples from the drylands of ACA. The distribution of brGDGTs in relation to climate and environmental variables was analysed to explore their potential as reliable temperature proxies, mainly focusing on brGDGTs methylation (MBT), cyclisation (CBT), and isomer (IR) indices. The brGDGT-based palaeothermometer is a promising tool for understanding past climates, but our comparison between an ACA-centred database and a worldwide continental surface sample database reveals several challenges. Drylands exhibit extreme climate and soil/lacustrine properties, amplifying the impact of confounding factors on brGDGT-based relationships with mean annual air temperature. Salinity emerges as the dominant factor influencing brGDGT variance, followed by sample type, pH, and aridity, all of which contribute significantly. These factors interact in complex ways, with the salinity effect varying between soil and lacustrine deposits. For sample physicochemical conditions, the IR6+7Me ' index is best for salinity, and IR6Me is most suitable for pH reconstruction. Thus, the MBT5Me '-temperature relationship is limited in ACA, particularly for lacustrine samples, and MBT6Me ' does not offer a better solution under hyper- to semi-arid conditions. Sub-calibrating models for specific environmental conditions such as salinity and aridity improves the accuracy of temperature reconstructions. Furthermore, the difference between MBT5Me ' and MBT6Me ' provides a promising proxy to assess aridity. Although the brGDGT signal in drylands is influenced by multiple controlling factors, it remains a valuable tool for understanding past climate and environmental conditions, especially when accounting for the complex interactions between these factors based on each study's unique physicochemical and bioclimatic context. Further research, incorporating a broader range of surface samples alongside comprehensive soil and climate data, holds the potential to enhance the accuracy of brGDGT-based climate reconstructions.

Soil-borne microbiomes harbour vital genetic resources, encompassing gene richness and dissimilarity, an indicator of the degree of diversity and distinctiveness exhibited by the gene repertoire of the soil microbiome. These genetic resources underlie key microbial traits and enzyme profiles that support terrestrial ecosystem functioning, including nutrient cycling, plant productivity and soil health. Despite their importance, global patterns and protection status of such resources remain poorly resolved. Here we compile 1,609 soil metagenomes to map global patterns of microbial functional gene richness and dissimilarity. Hotspots of gene dissimilarity concentrate in tropical regions, whereas gene richness hotspots are more widely distributed. Areas combining both high richness and dissimilarity are rare, covering only 5.5% of the terrestrial surface of the Earth, while drylands emerge as prominent hotspots for microbial traits and enzyme profiles. Fewer than 25% of hotspots for soil microbial genetic resources fall within designated protected areas. Notably, the global patterns of soil microbial functional profiles are largely decoupled from those of bacterial and fungal taxonomic diversity, suggesting that taxon-based conservation policies may not adequately safeguard belowground genetic resources. Our work provides an actionable baseline to integrate soil microbial genetic resources into global biodiversity targets and protected-area planning. Soil microbiomes harbour diverse genetic resources that underpin their capacity to provide crucial ecosystem services (for example, nutrient cycling). Here the authors map global hotspots of soil microbial genetic resources from 1,609 soil metagenomes to inform actionable targets for their protection.

Drivers of non-native plant success in drylands are poorly understood. Here we identify functional differences between dryland native and non-native perennial plants and assess how biotic, abiotic and anthropogenic factors shape the success of the latter. On the basis of plant community and functional trait data from 98 sites across 25 countries, we report a total of 41 non-native plant species at 31 sites. Non-natives tend towards faster growth strategies than natives. Non-native plant richness is higher at sites with greater grazing pressure and under environmental conditions associated with higher soil fertility, decomposition and fungal richness-conditions that tend to occur in less arid regions-and lower where native plant and herbivore richness are greater. Non-native plant cover correlates positively with grazing pressure and negatively with native plant richness. Taken together, our results suggest that non-native plant success in drylands is facilitated when high grazing pressure coincides with elevated resource availability. Such context-dependence of non-native plant success and linkages with native plant and herbivore diversity highlight the need for managing grazing and conserving biodiversity across the world's drylands.

Forest disturbance alters habitat structure and strongly influences saproxylic beetle communities in boreal forests. We investigated how disturbance type and severity shape beetle diversity and community composition in the boreal forests of the Green Zone surrounding Ulaanbaatar, Mongolia. Using a fully factorial design (three forest types × four disturbance severity levels) sampled over three years, we quantified species richness, Shannon diversity, total abundance, and the abundance of fire-favoured beetles. Disturbance type, severity, and their interaction significantly influenced all response variables. Burnt forests supported higher diversity, richness, and abundance—particularly of fire-favoured taxa—than insect-damaged forests. Abundance of fire-favoured beetles declined from high-severity to control conditions, whereas Shannon diversity peaked at moderate disturbance, consistent with increased habitat heterogeneity. Differences in species richness were comparatively modest. Indicator species analyses highlighted the prominence of xylophagous taxa, particularly Buprestidae and Cerambycidae, under higher disturbance severity. Community composition differed markedly among disturbance types, with both disturbance-related variables and stand structural attributes jointly shaping assemblages. Our results highlight the importance of disturbance-generated post-disturbance habitat structures, particularly deadwood, in maintaining saproxylic biodiversity. Conservation-oriented forest management should prioritize the retention of post-disturbance substrates, especially following moderate to high-severity disturbances, to sustain biodiversity under increasing natural and anthropogenic impacts.

Abstract Sustainable management of pastoral landscapes is essential for conserving steppe biodiversity and preventing desertification. In the arid grasslands of Central Asia, livestock overgrazing is a major driver of habitat degradation, yet the ecological responses of terrestrial arthropods, key components of these ecosystems, remain poorly understood. We tested how cessation of domestic grazing affects beetle assemblages by comparing traditionally grazed sites with sites ungrazed for short (<5 years) and long (>10 years) periods in western Mongolia. In addition to composition, we assessed responses of beetle species by their functional traits such as body size, dispersal mode and trophic guild. In total, 986 individuals representing 106 beetle species were recorded. Community composition differed significantly among all management categories, with the strongest separation between grazed and short‐term cessation sites. On the other hand, functional composition of beetles did not differ between the sites with different ungrazing regimes, although trait‐based analyses revealed that short‐term cessation (<5 years) was associated with large‐bodied species. Our findings suggest that traditional nomadic grazing is associated primarily with shifts in species composition, while functional structure appears comparatively stable and may be shaped by additional environmental factors in Mongolian steppes. Management approaches that favour short‐term grazing cessation or spatially heterogeneous grazing (e.g., rotational or patch grazing) may help maintain habitat heterogeneity and support insect diversity in steppe ecosystems.

Anthropogenic biodiversity decline threatens the functioning of ecosystems and the many benefits they provide to humanity1. As well as causing species losses in directly affected locations, human influence might also reduce biodiversity in relatively unmodified vegetation if far-reaching anthropogenic effects trigger local extinctions and hinder recolonization. Here we show that local plant diversity is globally negatively related to the level of anthropogenic activity in the surrounding region. Impoverishment of natural vegetation was evident only when we considered community completeness: the proportion of all suitable species in the region that are present at a site. To estimate community completeness, we compared the number of recorded species with the dark diversity-ecologically suitable species that are absent from a site but present in the surrounding region2. In the sampled regions with a minimal human footprint index, an average of 35% of suitable plant species were present locally, compared with less than 20% in highly affected regions. Besides having the potential to uncover overlooked threats to biodiversity, dark diversity also provides guidance for nature conservation. Species in the dark diversity remain regionally present, and their local populations might be restored through measures that improve connectivity between natural vegetation fragments and reduce threats to population persistence.

Forest fires are part of taiga ecosystem dynamics in northern Mongolia. We studied beetle diversity and community structure in 98 plots at five sites in different forest types (light taiga, mixed taiga, dark taiga, floodplain forest) and under different fire regimes. Each plot included five pitfall traps, one soil and litter sampling and recording of environmental variable measurements. We used Hill numbers, GLMM and RDA to evaluate the data. In total, we collected 2692 individuals of 130 species and 72 genera of beetles, mainly Carabidae, Staphylinidae, Silphidae, and Leidodidae, with Pterostichus eximius occurring in 60% of all plots. Forest fires had a significant effect on diversity and community structure of Coleoptera at the local level. However, in all data, the effects of site and forest type outweighed the influence of fire. An RDA explained 32% of the variation in community patterns with the effects of fire and environmental parameters. RDA1 scores differed significantly by fire regime, suggesting different species composition of post-fire communities. Hylobius abietis, Byrrhus pilula and Leiodes sp2 were identified as indicator species for fire plots. Protection of beetle refugia is critical for successful habitat recolonization, but is threatened by the post-fire salvage logging practices common in Mongolian forestry. (c) 2024 National Science Museum of Korea (NSMK) and Korea National Arboretum (KNA). Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).

Amid global challenges like climate change, extinctions, and disease epidemics, science and society require nuanced, international solutions that are grounded in robust, interdisciplinary perspectives and datasets that span deep time. Natural history collections, from modern biological specimens to the archaeological and fossil records, are crucial tools for understanding cultural and biological processes that shape our modern world. At the same time, natural history collections in low and middle-income countries are at-risk and underresourced, imperiling efforts to build the infrastructure and scientific capacity necessary to tackle critical challenges. The case of Mongolia exemplifies the unique challenges of preserving natural history collections in a country with limited financial resources under the thumb of scientific colonialism. Specifically, the lack of biorepository infrastructure throughout Mongolia stymies efforts to study or respond to large-scale environmental changes of the modern era. Investment in museum capacity and training to develop locally-accessible collections that characterize natural communities over time and space must be a key priority for a future where understanding climate scenarios, predicting, and responding to zoonotic disease, making informed conservation choices, or adapting to agricultural challenges, will be all but impossible without relevant and accessible collections.

Saproxylic beetles, as primary decomposers in forest ecosystems, play a crucial role in the decomposition of dead wood. However, there is a significant gap in understanding the extent of assemblages and damage caused by these insects, which is essential for managing the quality and utilization of dead wood resources in natural forests. This study employed the Bevan damage classification system to quantify the severity of saproxylic beetle damage to fallen trees, focusing on the boreal forest in the Green zone of Ulaanbaatar, the capital of Mongolia. A factorial design was used to assess the influence of forest landscape (north vs. south mixed forest), tree species (Siberian spruce Picea obovata and Siberian pine Pinus sibirica), and decay class (1-4) on beetle damage indices, abundance and feeding guilds (cambium consumers, wood borers, predators, parasitoids, and detritivores). Our findings reveal that decay class significantly affects beetle abundance and damage severity with early stages showing the highest values. Cambium consumers and wood borers were more abundant in decay class 1 (DC1) for downed spruce, with Ips typographus (24.7%) and Tetropium castaneum (15%) causing the most damage. For the Siberian pine, Monochamus galloprovincialis (9.8%) and Judolia sexmaculata (13.3%) were the most damaging in DC1 followed by Pityogenes conjunctus (10%). The results suggest that Siberian spruce may be more susceptible to saproxylic beetle damage than the Siberian pine, with structural features such as bark cover branch size and wood moisture playing a critical role, especially in early decay stages. Based on our findings, we recommend decay-stage-specific management approaches, particularly targeting early decay stages (DC1-DC2) where beetle damage is most severe. Practical strategies include early detection of freshly downed trees, bark removal to reduce suitable habitat for cambium consumers, and on-site processing techniques such as bark gouging or mechanical debarking. These methods allow deadwood biomass to be retained in the forest while reducing pest pressure, offering a viable alternative to salvage logging. Such approaches are especially relevant in protected areas, where they can support both pest control and biodiversity conservation objectives. However, given the geographic scope limited to boreal forests of Ulaanbaatar, caution should be exercised in extrapolating these recommendations to other regions without further study.

The origins and prehistory of domestic sheep (Ovis aries) are incompletely understood; to address this, we generated data from 118 ancient genomes spanning 12,000 years sampled from across Eurasia. Genomes from Central Türkiye ~8000 BCE are genetically proximal to the domestic origins of sheep but do not fully explain the ancestry of later populations, suggesting a mosaic of wild ancestries. Genomic signatures indicate selection by ancient herders for pigmentation patterns, hornedness, and growth rate. Although the first European sheep flocks derive from Türkiye, in a notable parallel with ancient human genome discoveries, we detected a major influx of Western steppe-related ancestry in the Bronze Age.

Rhizospheric microbiomes differ between active and dormant plants due to changes in root activity and exudate production, especially under environmental stress. In arid regions, native plants such as Potaninia mongolica Maxim enter dormancy to survive harsh conditions. However, rhizospheric microbial and chemical differences between active and dormant states of plants remain poorly described. This study investigated rhizospheric microbial communities and soil chemical changes in the case of active and dormant P.mongolica plants. Rhizospheric soil samples were collected, and soil texture and chemical variables were analyzed. High-throughput sequencing targeting the 16S rRNA and ITS regions was conducted to profile bacterial and fungal communities, respectively. Results showed that the dominant fungal phyla were Ascomycota and Basidiomycota, while Proteobacteria and Actinobacteria were the dominant bacterial phyla in both plant states. Although bacterial diversity did not differ significantly between active and dormant plants (p > 0.05, Welch’s t-test), fungal diversity was significantly different. Among soil chemical variables, total nitrogen was notably elevated in the rhizosphere of dormant plants (mean = 7.93; SD = 5.91). These findings reveal differences in fungal community structure and nitrogen levels in the rhizosphere between active and dormant plant states. Understanding these interactions contributes to our knowledge of desert plant microbiome dynamics and may inform the use of microbial indicators or amendments to support vegetation restoration in arid environments.

Mineral-associated organic carbon (MAOC) constitutes a major fraction of global soil carbon and is assumed less sensitive to climate than particulate organic carbon (POC) due to protection by minerals. Despite its importance for long-term carbon storage, the response of MAOC to changing climates in drylands, which cover more than 40% of the global land area, remains unexplored. Here we assess topsoil organic carbon fractions across global drylands using a standardized field survey in 326 plots from 25 countries and 6 continents. We find that soil biogeochemistry explained the majority of variation in both MAOC and POC. Both carbon fractions decreased with increases in mean annual temperature and reductions in precipitation, with MAOC responding similarly to POC. Therefore, our results suggest that ongoing climate warming and aridification may result in unforeseen carbon losses across global drylands, and that the protective role of minerals may not dampen these effects..

Changes in climate and grazing intensity influence plant-community compositions and their functional structure. Yet, little is known about their possible interactive effects when climate change mainly has consequences during the growing season and grazing occurs off growing season (dormant season grazing). We examined the contribution of trait plasticity to the immediate responses in the functional structure of plant community due to the interplay between these two temporally disjunct drivers. We conducted a field experiment in the northern Mongolian steppe, where climate was manipulated by open-top chambers (OTCs) for two growing seasons, increasing temperature and decreasing soil moisture (i.e., increased aridity), and grazing was excluded for one dormant season between these two growing seasons. We calculated the community-weighted mean (CWM) and the functional diversity (FD) of six leaf traits. Based on a variance partitioning approach, we evaluated how much of the responses in CWM and FD to OTCs and dormant season grazing occur through plasticity. The interactive effect of OTCs and the dormant season grazing were detected only after considering the role of trait plasticity. Overall, OTCs influenced the responses in CWM more than in FD, but the effects of OTCs were much less pronounced where dormant season grazing occurred. Thus, warming (together with decreased soil moisture) and the elimination of dormant season grazing could interact to impact the functional trait structure of plant communities through trait plasticity. Climate change effects should be considered in the context of altered land use, even if temporally disjunct.

Earth harbours an extraordinary plant phenotypic diversity(1) that is at risk from ongoing global changes(2,3). However, it remains unknown how increasing aridity and livestock grazing pressure-two major drivers of global change(4-6)-shape the trait covariation that underlies plant phenotypic diversity(1,7). Here we assessed how covariation among 20 chemical and morphological traits responds to aridity and grazing pressure within global drylands. Our analysis involved 133,769 trait measurements spanning 1,347 observations of 301 perennial plant species surveyed across 326 plots from 6 continents. Crossing an aridity threshold of approximately 0.7 (close to the transition between semi-arid and arid zones) led to an unexpected 88% increase in trait diversity. This threshold appeared in the presence of grazers, and moved toward lower aridity levels with increasing grazing pressure. Moreover, 57% of observed trait diversity occurred only in the most arid and grazed drylands, highlighting the phenotypic uniqueness of these extreme environments. Our work indicates that drylands act as a global reservoir of plant phenotypic diversity and challenge the pervasive view that harsh environmental conditions reduce plant trait diversity(8-10). They also highlight that many alternative strategies may enable plants to cope with increases in environmental stress induced by climate change and land-use intensification.

Perennial plants create productive and biodiverse hotspots, known as fertile islands, beneath their canopies. These hotspots largely determine the structure and functioning of drylands worldwide. Despite their ubiquity, the factors controlling fertile islands under conditions of contrasting grazing by livestock, the most prevalent land use in drylands, remain virtually unknown. Here we evaluated the relative importance of grazing pressure and herbivore type, climate and plant functional traits on 24 soil physical and chemical attributes that represent proxies of key ecosystem services related to decomposition, soil fertility, and soil and water conservation. To do this, we conducted a standardized global survey of 288 plots at 88 sites in 25 countries worldwide. We show that aridity and plant traits are the major factors associated with the magnitude of plant effects on fertile islands in grazed drylands worldwide. Grazing pressure had little influence on the capacity of plants to support fertile islands. Taller and wider shrubs and grasses supported stronger island effects. Stable and functional soils tended to be linked to species-rich sites with taller plants. Together, our findings dispel the notion that grazing pressure or herbivore type are linked to the formation or intensification of fertile islands in drylands. Rather, our study suggests that changes in aridity, and processes that alter island identity and therefore plant traits, will have marked effects on how perennial plants support and maintain the functioning of drylands in a more arid and grazed world. In global drylands, soils tend to be more fertile beneath tree, shrub and grass islands. Soil fertility was greater beneath taller and wider plants but was unaffected by either grazing pressure or the type of herbivore.

Increases in the abundance of woody species have been reported to affect the provisioning of ecosystem services in drylands worldwide. However, it is virtually unknown how multiple biotic and abiotic drivers, such as climate, grazing, and fire, interact to determine woody dominance across global drylands. We conducted a standardized field survey in 304 plots across 25 countries to assess how climatic features, soil properties, grazing, and fire affect woody dominance in dryland rangelands. Precipitation, temperature, and grazing were key determinants of tree and shrub dominance. The effects of grazing were determined not solely by grazing pressure but also by the dominant livestock species. Interactions between soil, climate, and grazing and differences in responses to these factors between trees and shrubs were key to understanding changes in woody dominance. Our findings suggest that projected changes in climate and grazing pressure may increase woody dominance in drylands, altering their structure and functioning.