Aims Tree species can shape soil fauna communities by modifying both soil environment and litter properties, but their independent influences remain poorly understood due to natural covariation.
Methods To disentangle the drivers of soil and litter properties, we conducted a litter reciprocal transplant experiment in a subtropical common garden established in 2012, selecting three tree species with distinct litter properties: Castanopsis (Castanopsis carlesii, evergreen broadleaf), fir (Cunninghamia lanceolata, evergreen coniferous), and sweetgum (Liquidambar formosana, deciduous broadleaf). Over a completely broadleaf litter decomposition period from March to October 2024, soil fauna communities were monitored across all plantation-litter combinations.
Important Findings We found that Entomobryidae dominated soil fauna community, and saprophages were the most abundant functional group (46.76%) regardless of plantation types and litter types. Tree-mediated soil environment rather than litter was the primary driver of total fauna abundance (57.10% variation explained), taxon number (78.60%), diversity (68.90%), and evenness (72.40%). Compared with other plantation types, the Castanopsis forest stand supported a higher soil fauna abundance. Litter properties exhibited another considerable explanatory power for soil fauna abundance (42.90%). Higher soil fauna abundance was detected in sweetgum than fir litter, with marked differences at early/middle decomposition stages (29–63 days). Predators/saprophages were more sensitive to changes in habitat conditions than herbivores/omnivores. Key regulators of tree species on soil fauna during litter decomposition included soil moisture and nitrogen content in soil environment as well as mass remaining and carbon content in litter properties. These findings advance understanding of tree species effects on soil fauna, supporting subtropical forest biodiversity conservation and sustainable management.

Anthropogenic habitat fragmentation is a major driver of biodiversity loss in terrestrial ecosystems. However, its effects on species interaction networks remain poorly understood, especially for soil microbial communities. Using 23 grassland fragments within an agricultural mosaic of the agro-pastoral ecotone of northern China, we investigated the cascading effects of habitat fragmentation on soil microbial networks mediated by biodiversity. We found that habitat fragmentation negatively influenced soil microbial diversity and networks primarily by reducing patch area. Larger patches supported higher species richness and more complex and stable networks of soil bacteria and fungi. Habitat fragmentation induced reduced patch area had no direct effect on network complexity and stability, but indirectly decreased network complexity and stability by decreasing the species richness of soil bacteria and fungi. Our findings demonstrate that habitat fragmentation not only declines soil microbial biodiversity but also simplifies and destabilizes soil microbial networks in the agro-pastoral ecotone of northern China. We suggest that examining soil microbial network patterns in remnant habitats can provide valuable insights into the ecological consequences of habitat fragmentation beyond biodiversity loss.

The plasticity of both sexual reproduction and clonal growth is crucial for the adaptation of clonal plant populations, with trade-offs often observed between these two ecological processes. Vegetative ramets are essential for clonal growth, yet their role in regulating the plasticity of sexual reproduction, especially under nitrogen (N) enrichment, remains poorly understood. A series of field and pot experiments were conducted to test how vegetative ramets affect the plasticity in sexual reproduction within a clonal fragment (units of reproductive ramet with different number of vegetative ramets), in perennial Leymus chinensis under N application. Results showed that the densities of both vegetative and total ramets exhibited a significant increase in response to rising N concentrations. Throughout all N concentrations in situ, L. chinensis population predominantly consisted of independent reproductive ramets that were not physically connected to vegetative ramets. Furthermore, N application increased the proportion of reproductive ramets that connected with a greater number of vegetative ramets. Independent reproductive ramets exhibited generally the poorest sexual reproductive characteristics across all N concentrations. Resource translocation between ramets was bidirectional with net translocation preferentially flowing toward vegetative ramets during the milk-ripe stage. N application produced only a limited enhancement of sexual reproductive traits. Our study provides the first comprehensive explanation for the poor sexual reproduction of L. chinensis from the perspectives of clonal fragment types and the nutrient supply mechanisms underlying its predominantly vegetative propagation strategy. We further elucidate the underlying factors contributing to the poor sexual reproduction performance but high plasticity via nutrient translocation among ramets in situ.

Land use is widely regarded as a major driver of biodiversity loss, yet its effects on mountain ecosystems remain unclear and may be inconsistent across spatial scales due to pronounced environmental heterogeneity. However, few studies have simultaneously quantified multi-scale (α, β and γ) diversity responses to land use along mountain gradients. We hypothesized that under certain levels of disturbance, traditional land use (e.g. agriculture, planted forestry, and secondary forestry) can enhance environmental and landscape heterogeneity, thereby sustaining or even increasing diversity at specific spatial scales rather than uniformly reducing it. In the Hengduan Mountains, a global biodiversity hotspot with complex topography and long-standing traditional land use, We quantified plant α (species richness), β (species turnover), and γ diversity (regional species pool) across different vegetation belts under varying land use intensity (LUI). We found that land use significantly reduced α by 21.7% (P < 0.001) but increased β by 5.9% (P < 0.05) and γ by 16.3% (P < 0.05) relative to natural forests. These effects varied with elevation: α diversity increased at low elevations by 32.8% (P < 0.05) but declined at mid- and high elevations. Both β and γ diversity showed unimodal response to LUI, peaking at moderate intensity (0.2–0.4). Precipitation mediated α and γ responses, whereas altitude governed β diversity responses, indicating biodiversity responses to land use are mediated by distinct ecological processes operating across spatial scales. PLS-SEM further showed that γ diversity was driven mainly by β diversity rather than α diversity. These findings challenge conventional wisdom that land use impacts are uniformly negative and highlight the importance of maintaining moderate land use intensity and landscape heterogeneity to conserve regional biodiversity in mountainous landscapes.

Aims
Spatial heterogeneity of key soil resources is fundamental to grassland ecosystem stability and strongly shaped by livestock grazing. Existing research has largely prioritized single livestock species, leaving our understanding of how different species and assemblages regulate soil resources and their spatial patterns relatively limited. This study aims to evaluates the effects of diverse livestock assemblages on key soil resources in alpine grasslands.
Methods
We conducted an eight-year controlled grazing experiment in the alpine grasslands of the Qinghai-Tibet Plateau to evaluate the impacts of yak alone, Tibetan sheep alone, and mixed grazing (ratios of 1:2, 1:4, and 1:6) on key soil properties and their spatial heterogeneity.
Important Findings
Our results indicated that soil available nitrogen, water content, and bulk density were the key physicochemical properties driving changes in plant and microbial communities under grazing. Grazing by Tibetan sheep alone induced the greatest increase in the spatial heterogeneity of soil available nitrogen and compaction (59.41% and 34.76%), whereas grazing by yaks alone caused the most significant rise in the spatial heterogeneity of soil water content (67.24%). Trampling and excretion by livestock accounted for 56.65% to 76.16% of the variation in soil heterogeneity, exerting a stronger influence than the spatial heterogeneity of vegetation communities. These findings highlight the pivotal role of different livestock assemblages in regulating the spatial heterogeneity of key soil resources in alpine grasslands and suggest that future adaptive management must fully consider the specific impacts of different livestock assemblages on soil resources and ecosystem dynamics.