Bryophytes are primary producers in crucial global ecosystems, significantly contributing to carbon cycling through photosynthesis. Systematic understanding of photosynthesis of bryophytes and influencing factors will provide new perspectives and pathways for the ecosystem carbon cycling and carbon neutrality. However, current research on photosynthesis of bryophytes and its influencing factors remains poorly studied. Based on systematic literature search and analysis, this review indicates a mean maximum net photosynthetic rate (A_max) of 29.61 nmol CO₂ g^-1 s^-1 in bryophytes, about 20% of that in vascular plants, showing significant interspecific differences and intraspecific variations. Mass-based Amax follows the order: Thalloid liverworts > Acrocarpous mosses > Pleurocarpous mosses > Sphagnum mosses > Leafy liverworts. Key factors regulating bryophyte photosynthetic capacity are examined, including plant structure and morphology, anatomical features (e.g., cell wall thickness), environmental factors (light, water, temperature), and colony structure (numerical density, colony mass per unit area, leaf area index). Future studies are needed to investigate: (1)how photosynthetic capacity varies across the phylogenetic spectrum of bryophytes; (2) how the mechanisms underlying colony structure influence bryophyte photosynthesis can be determined; (3)how the interactive effects of multiple factors on bryophyte photosynthesis can be studied; and (4)how bryophyte photosynthesis and carbon sequestration potential vary across large spatiotemporal scales.

Tree height and radial growth, key to forest productivity and carbon sink capacity, however, their responses to warming may differ. Here, we review the main observation methods for tree height and radial growth, compare detection techniques employed in both warming manipulation experiments and field observations, and systematically summarize the ecological and physiological mechanisms by which warming affects these growth processes. Overall, due to technical limitations in continuous tree height measurement, most studies have focused on radial growth responses to warming, while evidence on tree height growth remains limited. Mechanistically, tree height growth is primarily regulated by hormone signaling in apical meristem and photosynthate allocation strategies. In contrast, tree radial growth depends more on cambial activity and non-structural carbohydrate storage, making it more sensitive to drought stress and carbon balance regulation. Warming primarily affects tree height and radial growth by altering carbon allocation, water-use efficiency, nutrient uptake, and phenological timing. Its effects show substantial heterogeneity across latitudes, tree functional traits, and environmental conditions. The key priority for future research is to strengthen the integration of high-resolution monitoring technologies such as LiDAR for height growth and automated dendrometers for radial growth, while emphasizing the interactions and legacy effects between warming and key limiting factors such as water and nutrient availability. These approaches will improve predictive capacity for forest productivity and offer a theoretical foundation for adaptive carbon sink management under global warming.

Global warming profoundly affects the nitrogen (N) cycle in forest soils, but the direction of its impact (promotion or inhibition) on soil N mineralization processes (ammonification and nitrification) in different forest types and its temperature sensitivity (Q₁₀) remain unclear. This study selected Pinus massoniana mixed conifer-broadleaf forest (PLL) and Lithocarpus glaber-Cyclobalanopsis glauca evergreen broad-leaved forest (LCC) in the hilly areas of central-southern Hunan Province. Using a constant-temperature incubation method at 10, 25, 30, and 40 ℃, the net ammonification rate (N_AR), net nitrification rate (N_NR), and net N mineralization rate (N_MR) in the 0—10 cm and 10—20 cm soil layers were measured. The relationship between the mineralization rate and temperature was fitted by an exponential model to calculate Q₁₀, and the relationships with biological and abiotic factors were analyzed. The results showed that: (1) The interaction between temperature and forest type and soil depth was significant, manifested as: the N_AR, N_NR, and N_MR of LCC were generally significantly higher than those of PLL, and the differences varied with soil depth and temperature (especially for N_NR); the N_AR and N_MR of both forest soils increased significantly with increasing temperature, while NNR reached a peak at 30 ℃ and then decreased; all rates decreased with increasing soil depth, and the advantage of soil mineralization rate in the surface layer (0-10 cm) was more significant at high temperatures; the activity of soil ammonia-oxidizing microorganisms was the strongest at 30～40 ℃, while the activity of nitrifying microorganisms was the strongest at 10～25 ℃, resulting in a decrease in N_NR at high temperatures (40 ℃). (2) The N_AR-Q₁₀ (2.00—2.01) and N_MR-Q₁₀ (2.01—2.02) of all soil layers in PLL were significantly higher than those in LCC (1.89—1.95 and 1.93—1.94), indicating that the N transformation in PLL soil was more sensitive to warming. Only in the 10—20 cm soil layer of LCC was the N_AR-Q₁₀ significantly higher than that in the surface layer (0—10 cm) soil. (3) N_AR was mainly regulated by the carbon-nitrogen ratio of the litter layer and soil total nitrogen; N_NR and N_MR were mainly driven by microbial biomass phosphorus (MBP) and total nitrogen in the litter layer; N_AR-Q₁₀ was mainly affected by MBP and urease activity; while N_MR-Q₁₀ was mainly regulated by soil inorganic nitrogen. In conclusion, warming significantly promoted the N mineralization process in subtropical forest soils (except for NNR at >30 ℃), and the Q₁₀ of N mineralization in PLL soil was higher than that in LCC. LCC showed higher N mineralization rates and lower temperature sensitivity, highlighting the importance of protecting existing natural forests for maintaining the stability of the soil N cycle and responding to climate change. This study provides a scientific basis for understanding the response mechanism of the soil N cycle in subtropical forests to climate change and optimizing forest management measures.

Aims Interspecific competition is a key process regulating plant community assembly and productivity, and nitrogen and phosphorus availability are major factors influencing interspecific competitive interactions among wetland plants. However, systematic understanding of the differences between aboveground and belowground competition, especially under nitrogen and phosphorus enrichment conditions, remains limited, hindering predictions of wetland community dynamics. Methods We conducted a greenhouse experiment with two plant species, coexisting and habitat-similar dominant perennial species in the Poyang Lake, Carex cinerascens and Phalaris arundinacea. Experimental treatments included four competition treatments (no competition, aboveground competition [AGC], belowground competition [BGC], and both competition) and four nutrient conditions (control, nitrogen addition [N], phosphorus addition [P], and combined nitrogen–phosphorus addition [NP]). Aboveground and belowground biomass of both species were measured under each treatment to evaluate biomass allocation strategies. Relative interaction index (RII) under different nutrient conditions were calculated to assess the effects of nutrient inputs on interspecific competition. Important findings 1) BGC was the primary driver of growth and biomass allocation, with C. cinerascens showing a strong BGC advantage and maintained overall dominance by allocating more biomass to aboveground parts, whereas P. arundinacea was suppressed by BGC and allocated more biomass to belowground parts to alleviate this suppression; 2) N addition reduced the BGC advantage of C. cinerascens, P addition alleviated the suppressive effects of BGC to P. arundinacea, and NP addition enhanced its competitive advantage while reducing inhibition of P. arundinacea, resulting in increased total biomass; 3) The effects of nutrient inputs on interspecific competition were primarily driven by interactive effects of AGC and P addition on belowground biomass, and by interactive effects of BGC and N addition on aboveground biomass. Conclusions Nutrient addition can alter interspecific competitive relationships between plant species, but only synchronous changes in nitrogen and phosphorus availability can enhance total biomass while maintaining table biomass proportions between the two species . Therefore, under future nutrient-enrichment scenarios, coordinated regulation of nitrogen and phosphorus is critical for sustaining productivity and diversity in wetland plant communities.

Aims This study employs multisource satellite remote sensing data to evaluate vegetation damage on Hainan Island following the 2024 super typhoon Capricorn, while investigating the relationship between typhoon trajectory and vegetation impairment to establish scientific foundations for post-disaster restoration. Methods Through Sentinel-2 remote sensing imagery analysis of NDVI combined with spatial overlay analysis of typhoon trajectories, this research elucidates the spatiotemporal differentiation of damage mechanisms and vegetation response dynamics. Important findings After the typhoon passed through the island in September 2024, the average NDVI across the entire island decreased by 8.74% (relative to the pre-disaster baseline value). Analysis of imaging pixel coverage showed that 66.21% of the area experienced vegetation degradation, with obvious structural damage to forestland and shrub communities. As of March 2025, after a 6-month natural recovery period, systematic restoration showed a polarized trend: in the continuously degraded areas (70.85%), the average NDVI decreased by another 8.07% compared with the initial stage of the disaster (with a total decrease of 16.11%). The recovery gradient characteristics of vegetation functional groups are distinct: the damage sensitivity follows the order of mangroves > forestland > shrubs > grasslands > croplands > bare land/sparse vegetation; the recovery resilience intensity is expressed as mangroves > forestland > croplands > grasslands and shrubs > bare land/sparse vegetation. Overall, seasonal fluctuations are a significant influencing factor for the continuous decline of vegetation NDVI, with a contribution rate of 56.20%, while typhoons are an important driver of the negative growth of NDVI, with a contribution rate of 38.30%. This study provides detailed data support for the accurate assessment of large-scale vegetation damage on Hainan Island caused by extreme weather and post-disaster recovery.

Aim Ephemeral rivers are important ecological corridors and biological refuges in arid regions, but the interactive effects of elevation and ephemeral rivers on plant community structure and distribution in arid regions remain unclear. Therefore, this study focuses on the West Tugou and Daquan River basins within the Dunhuang Basin in the arid region of Northwest China. It investigates the differences in individual plant size, species distribution, and community structure inside and outside the ephemeral rivers, and explores whether there are interactive effects between ephemeral rivers and elevation gradients on plant communities. Method The Mann–Whitney U test was used to compare the differences in plant community characteristics between the upstream and downstream of the ephemeral river. A multi-level mixed-effects model was employed to analyze and investigate the interactive effects of the river and altitude on the plant community. A generalized additive model was utilized to identify the nonlinear characteristics of the altitude response. The Wilcoxon signed-rank test was used to assess whether there was a significant shift in the upper and lower limits of the distribution of common species. Important findings 1) The ephemeral river broke through the vertical zonation distribution of species under the water and heat limitations of the arid area. It not only increased the number of species (the total number of species within the river was 1.9–2.7 times that of the outside), but also significantly reduced the lower limit of species distribution in the river channel (p < 0.05) for the Xitugou river. The Daquan River also showed a downward trend, but the upper limit of species distribution in both river basins did not show a comprehensive upward movement. 2) The Mann-Whitney U non-parametric test showed that the average plant height and crown width inside both rivers were significantly higher than those outside (p < 0.05). In the West Tugou area, vegetation coverage was significantly greater inside the river than outside (p < 0.05), whereas in the Daquan River area, plant density was significantly greater outside the river than inside (p < 0.05); other community characteristics showed no statistically significant differences. 3) As the altitude increases, the average height and average canopy width of plants inside and outside the river decrease, while the vegetation coverage and plant density increase. Moreover, the decrease or increase in the river area is more significant. 4) The mixed effect model indicates that altitude and river location jointly drive the changes in vegetation coverage, plant density, and community structure. The average height is mainly influenced by altitude, reflecting the nonlinear regulation of hydrological and geomorphic processes on community formation in different altitude zones.

Abstract Aims Rheum tanguticum is a famous medicinal plant in China. The adaptability of its ex-situ conservation was analyzed and evaluated by biological characteristics, ecological stoichiometric characteristics and medicinal ingredients, which provided theoretical basis for resource conservation and introduction and return R. tanguticum. Methods The present study was based on the wild and ex-situ conservation investigation, using independent samples t-test to analyze the differences in seed germination rate, nutrients of soil, plant leaf traits, photosynthetic indexes, ecological stoichiometric characteristics and nutrient recycling efficiencies and medicinal ingredient content of the roots of R. tanguticum in the Liupan Mountain and ex-situ conservation area, in order to explore the adaptability of ex-situ conservation of R. tanguticum. Important findings There was no significant difference between the ex-situ conservation area and the wild distribution area of R. tanguticum for leaf size, photosynthetic indexes, ecological stoichiometry characteristics and their ratios, while the mean value of N:P was less than 14 in both places, indicating that R. tanguticum might Nitrogen limitation existed. The nutrient resorption efficiencies of C and K of R. tanguticum was not significant difference between live in the ex-situ conservation area and wild distribution area, but there was significant differences in the nutrient recovery efficiencies of N and P. R. tanguticum could reproduce normally in the ex-situ conservation area, and the germination rate was not different from that of the wild distribution area. The contents of free anthraquinone and total anthraquinone in the 2-year-old root of R. tanguticum in the ex-situ conservation area were significantly higher than those of the wild distribution area, which were in accordance with the standard of the pharmacopoeia. In addition, a total of 3257 metabolites were identified in root of 2-year-old R. tanguticum from wild and ex-situ conservation, including 1029 no significantly different metabolites and 2246 differential metabolites. The chemical classification and enrichment pathways of the no significantly different and different metabolites did not show significant differences. Metabolites related to medicinal components such as aloe-emodin, rhein and emodin were not significantly different between ex-situ conservation and wild R. tanguticum. Conclusion After ex-situ conservation, R. tanguticum adapts to the ex-situ habitat in this study , grows well, and the quality of its effects does not change.

Aims The survival and growth of woody plant seedlings are regulated by a complex interplay of multiple environmental factors. However, how the forest canopy regulates understory herbaceous cover and microclimate to subsequently influence seedling survival and growth remains poorly understood. Methods This study investigated seedlings of three dominant species, Malus sieversii, Juglans regia, and Prunus armeniaca, in wild fruit forests in the Tianshan Mountains through five consecutive years of field surveys and microclimate monitoring. Important findings Our results show that canopy cover indirectly influenced the survival of seedlings of the three wild fruit tree species by regulating understory microclimate and herbaceous cover. Among these factors, herbaceous cover was an important determinant of seedling survival,existing negative effects on seedlings of M. sieversii and P. armeniaca, while demonstrating a positive effect on seedlings of J. regia. In terms of seedling growth, the key limiting factors differed among species. The growth of seedlings of M. sieversii was mainly affected by soil pH and herbaceous cover; the growth of seedlings of J. regia was primarily associated with herbaceous cover and mean temperature of the growing season; whereas the growth of seedlings of P. armeniaca was mainly constrained by mean temperature of the growing season. In conclusion, canopy cover regulates the survival and growth of wild fruit tree seedlings through multiple direct and indirect pathways, and the responses of seedlings of different tree species to biotic and abiotic factors differ significantly. The conservation and restoration of wild fruit forests should fully consider the differential responses of seedlings for different tree species to environmental factors and adopt targeted habitat management measures in the Tianshan Mountains.

Aims：This study aims to elucidate the annual growth dynamics of landscape trees under urban environmental conditions in Shenyang and their response to meteorological factors, thereby providing a reference for the cultivation and maintenance of ornamental tree species in Shenyang and the Northeast China region. Methods：This study employed the micro-core technique to monitor the radial growth dynamics of two urban tree species, Picea koraiensis and Phellodendron amurense, over two consecutive growing seasons (2023-2024) in Shenyang. The growth data were analyzed alongside meteorological data to elucidate the trees' response mechanisms to environmental factors. Important findings：Our investigation yielded two principal findings: (1) Cambial reactivation in both species initiated between late April and early May. The phase of cell enlargement and subsequent secondary wall thickening commenced approximately one week post-reactivation. Radial growth culminated in July, with complete growth cessation occurring by early to mid-October. The mean annual growth duration was quantified as 176 days for Picea koraiensis and 168 days for Phellodendron amurense. (2) The onset of cambial activity was positively correlated with rising temperature and precipitation early in the growing season. In contrast, the timing of growth cessation was independent of the reactivation chronology. Temperature was identified as the predominant environmental factor governing the radial growth dynamics of both species. This research provides a systematic characterization of the sp-temporal patterns of xylem development (xylogenesis) and the associated response mechanisms to environmental cues in Picea koraiensis and Phellodendron amurense within Shenyang's urban ecosystem. The insights gained offer a scientific basis for refining cultivation protocols and implementing precision silvicultural management for urban landscape trees across Shenyang and the Northeast China region.

To optimize stand management, enhance water regulation and carbon sequestration functions, this study explored the response mechanisms of water use efficiency (WUE) to key water-related factors in plantation ecosystems. A typical Platycladus orientalis plantation ecosystem in the mountainous area of Beijing was selected as the study site. Based on eddy covariance observations and the TEA model for evapotranspiration partitioning, ecosystem scale WUE (WUE_ET) and canopy scale WUE (WUE_T) were derived to analyze their temporal dynamics and the regulation mechanisms of water-related factors. During the growing season, the mean values of WUE_ET and WUE_T were 5.93±2.03 and 7.65±2.42 g C·kg^–1 H₂O, respectively, with consistent variation patterns. Vapor pressure deficit (VPD) was identified as the dominant factor controlling both WUE_ET and WUE_T: across different soil water content (SWC) quantiles, both indices exhibited significant negative sensitivities to VPD, primarily due to enhanced evapotranspiration (ET) and transpiration (T) under higher VPD, while gross ecosystem productivity (GEP) was not significantly suppressed. When SWC<0.20 m³·m⁻³, the negative sensitivity of WUE_T to VPD was stronger than that of WUE_ET. In contrast, under varying VPD conditions, both WUE_ET and WUE_T showed weak sensitivities to SWC, likely because GEP, ET, and T responded similarly to SWC changes, weakening its regulatory effect on WUE. With increasing air temperature (T_a) and photosynthetically active radiation (PAR), the negative sensitivity of WUE_ET and WUE_T to VPD gradually declined, while their sensitivity to SWC remained low. This study highlights the dominant role of atmospheric drought in regulating WUE across multiple scales in plantation forests, providing a scientific basis for developing precise water-management strategies and enhancing carbon-sink functionality in mountainous plantation ecosystems.

Aims By investigating plant responses to weathered bedrock moisture under varying soil water conditions, this study provides theoretical foundations for refining plant water-use mechanisms, with significant implications for understanding drought resistance strategies and ecohydrological processes. Methods This study selected Koelreuteria paniculata, Juniperus chinensis, and Pinus tabulaeformis as model species for a pot-based controlled experiment with two soil moisture treatments (10% and 20% volumetric water content). The experimental design involved precise regulation of moisture levels and stable isotopic compositions in both soil and weathered bedrock layers, along with controlled water exchange at their interface. Soil moisture sensors were deployed to monitor hydrological dynamics in these layers, while thermal dissipation probes (TDP) measured trunk sap flow density. Strategic sampling of plant xylem, soil, and weathered bedrock was conducted for hydrogen and oxygen stable isotope analysis (δ²H and δ¹⁸O). The isotopic signatures were subsequently quantified using the MixSIAR model to determine plant water-source partitioning among potential reservoirs. Important findings (1) With progressive drought duration, weathered bedrock moisture exhibited a declining trend under both 10% and 20% soil moisture treatments, with variation ranges of 2.99–4.44% and 0.93–3.10%. (2) Sap flow density of all species showed a consistent "initial decline followed by recovery" pattern under both treatments, with significantly higher values under 20% soil moisture. Notably, a significant positive correlation between daily mean sap flow density and bedrock moisture was observed only under 10% soil moisture (p < 0.05). (3) The contribution rate of bedrock water to three species increased significantly with drought progression. The contribution range under 10% soil moisture (33.8–52.5%) was significantly higher than under 20% soil moisture (27.8–45.1%). These findings collectively demonstrate plants' active ecological adaptation strategy of exploiting bedrock moisture to mitigate drought impacts, providing both theoretical and practical insights for vegetation restoration and water resource management in arid regions.

Abstract Aims The stoichiometriy of plant leaves, twigs, and fine roots are key indicators for characterizing whole-plant adaptive strategies and for revealing the mechanisms underlying plant-environment interactions. Investigating the interrelationships among leaf-twig-root stoichiometriy in desert plants, as well as their differences in environmental adaptability, is essential for advancing our understanding of plant resource allocation strategies. Methods In this study, we selected 20 desert plant species from the Baijitan region of Ningxia and measured the concentrations of carbon (C), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) in the leaves, twigs, and fine roots of 77 individuals. Important findings (1) Leaf C concentrations were significantly lower than those in twigs and fine roots, whereas the N, P, K, Ca, and Mg concentrations of twigs and fine roots were significantly lower than those of leaves. (2) Network analysis showed that the overall network parameters—edge density, average path length, diameter, average clustering coefficient, and modularity—were 0.40, 1.75, 4, 0.59, and 0.11, respectively; a total of 54 element-element pairs exhibited significant correlations. (3) Leaf K concentration and twigs C concentration exhibited the highest degree and closeness centrality, identifying them as hub elements within the network. Twigs showed the highest element degree, indicating that they function as the key hub organ. (4) Variance partitioning revealed that soil pH, total C, and total P had the strongest effects on the stoichiometry of leaves, twigs, and fine roots, respectively; soil total N had the greatest influence on leaf and twigs N concentrations, whereas soil pH most strongly affected fine-root C concentration. This study systematically uncovers the element coordination network among leaves, twigs, and roots of desert plants in the Baijitan region and elucidates their response mechanisms to soil environmental factors, providing new theoretical support for understanding desert plant ecological adaptation from a multi-element perspective. Our findings further highlight the need to incorporate key elements such as K, Ca, and Mg when examining plant stoichiometry, in order to more comprehensively reveal the coordinated regulation of C, N, P, K, Ca, and Mg across different organs and their roles in environmental adaptation.

Aims The ecological protection and restoration in the fragile dry-hot valleys have consistently garnered attention. However, how soil nutrients and stoichiometric characteristics respond to both artificial and natural restoration treatments across different altitude gradients in the dry-hot valleys remain unclear, especially regarding long-term effects. Methods The changes in soil environment (pH, moisture), soil nutrients (carbon, nitrogen, and phosphorus) and stoichiometric ratio (C:N:P) of degraded savanna in the dry-hot valleys of Yuanmou, Yunnan Province following 10 years of different vegetation restoration treatments have been examined across various altitude gradients. Important findings Soil moisture and nutrients under different restoration treatments changed significantly with the seasons. Compared to degraded forest, both artificial and natural restoration treatments significantly enhanced soil moisture and nutrients. However, the two restoration treatments promoted different nitrogen forms: artificial restoration increased NO3--N, while natural restoration promoted NH4+-N. The two artificial restoration treatments exhibited altitude-dependent. The Acacia confusa forest at mid altitude was more conducive to soil nutrients accumulation, whereas the Leucaena leucocephala forest at high altitude proved to be more beneficial. Soil stoichiometric ratios further demonstrated this interaction between restoration method and altitude. At mid altitude, the C:N of Leucaena leucocephala forest was significantly lower (9.96 in dry and 9.85 in rainy season, P < 0.05) than other treatments. At high altitude, the natural restoration showed significantly higher C:N (17.95) and N:P (13.08) during the dry season (P < 0.05). In general, natural restoration was more effective in soil nutrients accumulation than artificial restoration. It is recommended that natural restoration be adopted as the primary strategy, artificial restoration must adhere to altitude-specific tree species selection . These findings offer practical guidance for vegetation restoration and subsequent sustainable forest management in degraded ecosystems in dry-hot valleys.

Aims The rhizosphere microbial community, as a distinct group of microorganisms, serves as a key driver of nutrient cycling and energy flow within soil ecosystems, playing an essential role in maintaining ecosystem stability and functionality. As an integral component of the rhizosphere, the rhizosheath harbors a unique microbial community. However, the relationship between the rhizosheath microbial community and soil physicochemical properties may be closer than that observed in the broader rhizosphere. Methods This study focused on the perennial grass Stipagrostis pennata in the Gurbantunggut Desert. Using high-throughput sequencing, we analyzed microbial communities in the rhizosheath and bulk soil and constructed co-occurrence networks to elucidate community structure and its associations with environmental factors. Important findings The results indicated that the rhizosheath enhanced the diversity of soil microbial communities. Co-occurrence network analysis and linear regression models of soil bacteria and fungi revealed that, relative to bulk soil, the rhizosheath increased the complexity and stability of microbial co-occurrence networks. Furthermore, results from random forest and Mantel tests showed that the rhizosheath substantially reinforced the associations between microbial communities and soil physicochemical properties. Further analysis revealed that, during the transition from rhizosheath to bulk soil, network complexity was more sensitive to changes in soil physicochemical properties. Collectively, this study provides new insights into the complex interactions between rhizosheath-associated microbial communities and soil processes within the rhizosphere ecosystem.

Aims As a typical ecologically fragile zone in northern China, the Hexi Corridor is plagued by vegetation degradation and serious soil nutrient loss. As a key sand-fixing species in the Hexi Corridor, the degradation of Haloxylon ammodendron poses a serious threat to the ecological security of the region. The research about differences in soil microbial community characteristics and the influencing factors of artificial forests under different degradation levels was carried out, which can help to formulate reasonable restoration strategies. Methods In this study, the changes of soil physicochemical properties and microbial community diversity of artificial Haloxylon ammodendron forests under different degradation levels were analyzed in order to clarify the trend of microbial diversity and the key factors controlling the distribution of microbial communities in the degradation process of the forest land. Important findings The results showed that: (1) The content of Actinobacteriota, Chloroflexi and Acidobacteriota in bacteria increased significantly with the deterioration of forest land, while the content of Basidiomycota in fungi increased and then decreased, and the content of Chytridiomycota decreased and then increased; (2) The diversity of soil bacteria at moderate and heavy degradation was significantly higher than that of undegraded forest land, and the diversity of fungi was significantly higher than the rest of the degradation levels at slight degradation; (3) Soil organic carbon, total nitrogen, and total phosphorus were the main factors affecting the composition of soil bacterial communities in artificial Haloxylon ammodendron forests, while pH of soil, total nitrogen and water content were the main factors affecting the composition of fungal communities in forests. The study shows that there are differences in soil environmental factors affecting the composition and structure of soil microbial communities in artificial Haloxylon-ammodendron forests at different degradation levels. Therefore, when developing restoration strategies for degraded forests, differentiated ecological restoration strategies should be adopted based on the analysis of region-specific environmental drivers.

Cypripedium palangshanense is a plant species with an extremely small population (PSESP) listed among China's first batch of prioritized protected species. Difficulties in population regeneration and unclear mechanisms of endangerment highlight the urgent need for systematic community ecology research to inform its scientific conservation. Through examination of herbarium specimens and literature, combined with systematic field surveys and laboratory experiments, this study presents the first comprehensive analysis of its distribution, habitat, community structure, and reproductive capacity. The results show that: (1) Its distribution is confined to the Minshan and Daba Mountain ranges, with 15 confirmed extant populations (an increase of 9 compared to previous records), a vertical distribution range of 2365–2936 m, and a highly fragmented spatial pattern. (2) Its typical habitat is the shady, moist understory of subalpine coniferous forests with a thick moss layer. A total of 157 vascular plant species belonging to 48 families and 95 genera were recorded within its associated communities. The life-form spectrum is dominated by deciduous shrubs and perennial herbs, and the flora exhibits a North Temperate background intermixed with tropical elements. (3) TWINSPAN classification divided these communities into 6 association groups and 10 associations, indicating its ability to occur as a companion species across various coniferous forest types. (4) It exhibits an extremely low ratio of viable seeds from sexual reproduction (ca. 14.4%) and lacks clonal reproductive capacity, resulting in weak natural population regeneration. (5) All populations are subjected to high-intensity natural disturbances (landslides, debris flows, and flooding) and anthropogenic pressures (grazing and road construction). This study systematically clarifies the community ecological characteristics and severe survival threats faced by C. palangshanense, providing key scientific evidence for developing in situ conservation, habitat restoration, and artificial propagation strategies.