Bryophytes are primary producers in crucial global ecosystems, significantly contributing to carbon cycling through photosynthesis. Systematic understanding of photosynthesis of bryophytes and the influencing factors will provide new perspectives and pathways for the ecosystem carbon cycling and carbon neutrality, which has theoretical and practical significance. 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 and intraspecific variations. Mass-based A_max follows the order: Thalloid liverworts > Acrocarpous mosses > Pleurocarpous mosses > Sphagnum mosses > Leafy liverworts. Key factors regulating bryophyte photosynthetic capacity are further examined, including plant structure and morphology, anatomical features (e.g., cell wall thickness), environmental factors (light, water, temperature), and colony structure (colony 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) the mechanisms underlying colony structure influencing bryophyte photosynthesis; (3) how the interactions of multiple factors affect bryophyte photosynthesis; and (4) how bryophyte photosynthesis and carbon sequestration potential vary across large spatiotemporal scales.

Tree height growth and radial growth are key indicators of forest productivity and carbon sink capacity, but their responses to warming may differ. In this review, we summarize the main methods for observing tree height and radial growth, compare the detection techniques used in both warming manipulation experiments and field observations, and systematically examine the eco-physiological mechanisms underlying the effects of warming on these growth processes. Overall, due to technical limitations in continuous tree height measurement, most studies have focused on radial growth responses to warming, whereas 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, radial growth depends more on cambial activity and non-structural carbohydrate storage, making it more sensitive to drought stress and carbon balance regulation. Warming influences height and radial growth mainly by altering carbon allocation, water-use efficiency, nutrient uptake, and phenological timing. The effects vary significantly across latitudes, tree functional traits, and environmental conditions. Future research should prioritize integrating high-resolution monitoring technologies, such as LiDAR for height growth and automated dendrometers for radial growth, with a focus on the interactions and legacy effects between warming and key limiting factors such as water and nutrient availability. Such efforts will improve our capacity to predict forest productivity and provide a theoretical basis for adaptive carbon sink management under global warming.

Aims Global warming profoundly affects the nitrogen (N) cycle in forest soils; however, its direction (promotion or inhibition) and temperature sensitivity (Q₁₀) on soil N mineralization processes (ammonification and nitrification) across different forest types remain unclear.

Methods This study investigated a Pinus massoniana mixed needleleaf-broadleaf forest (PLL) and a Lithocarpus glaber-Cyclobalanopsis glauca evergreen broadleaf forest (LCC) in the hilly region of central-southern Hunan Province. Using a constant-temperature incubation method at 10, 25, 30, and 40 °C, the net ammonification rate (N_AR), net nitrification rate (N_NR), and net N mineralization rate (N_MR) were measured in the 0-10 cm and 10-20 cm soil layers. The relationship between the mineralization rate and temperature was modeled using an exponential function to calculate Q₁₀, and its relationships with biological and abiotic factors were analyzed.

Important findings 1) The interaction between temperature, forest type, and soil depth was significant. Specifically: the N_AR, N_NR, and N_MR of LCC were generally significantly higher than those of PLL, and the differences varing by soil depth and temperature, particularly for N_NR; the N_AR and N_MR of both forest soils increased significantly with increasing temperature, while N_NR peaked at 30 °C 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 highest at 30-40 °C, whereas the activity of nitrifying microorganisms was the strongest at 10-25 °C, resulting in a decrease in N_NR at high temperatures (40 °C). 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 N transformation in PLL soil was more sensitive to warming. Only in the 10-20 cm soil layer of LCC, the N_AR-Q₁₀ was significantly higher than the surface layer (0-10 cm). 3) N_AR was mainly regulated by the carbon-nitrogen ratio of the litter layer and soil total nitrogen content; N_NR and N_MR were mainly driven by microbial biomass phosphorus (MBP) and total nitrogen contents in the litter layer; N_AR-Q₁₀was mainly affected by MBP content and urease activity; whereas N_MR-Q₁₀ was mainly regulated by soil inorganic nitrogen content. In conclusion, warming significantly promoted N mineralization process in subtropical forest soils (except for N_NR at > 30 °C), and the Q₁₀ of N mineralization in PLL soil was higher than in LCC. LCC showed higher N mineralization rates but lower temperature sensitivity, highlighting the importance of preserving existing natural forests to maintain soil N cycle stability 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 for optimizing forest management strategies.

Aims Interspecific competition is a key process regulating plant community assembly and productivity, and nitrogen (N) and phosphorus (P) availability are major factors influencing these competitive interactions among wetland plants. However, systematic understanding of the differences between aboveground and belowground competition, especially under N and P enrichment conditions, remains limited, hindering predictions of wetland plant community dynamics.

Methods We conducted a greenhouse experiment with two plant species, Carex cinerascens and Phalaris arundinacea, coexisting and habitat-similar dominant perennial species in the Poyang Lake. Experimental treatments included four competition treatments (no competition, aboveground competition (AGC), belowground competition (BGC), and full competition) and four nutrient conditions (control, N addition, P addition, and combined NP addition. Aboveground and belowground biomass of each species was measured under each treatment to evaluate biomass allocation strategies. Relative interaction index 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 plant parts, whereas P. arundinacea was suppressed by BGC and allocated more biomass to belowground plant 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, while NP addition enhanced its competitive advantage with reducing inhibition of P. arundinacea, and resulting in increases in biomass of each species and in 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. Nutrient addition can alter interspecific competitive relationships between plant species, and only synchronous changes in N and P availability can enhance total biomass while maintaining their biomass proportions between the two species. Therefore, under future nutrient-enrichment scenarios, coordinated regulation of N and P is critical for sustaining productivity and diversity in wetland plant communities.

Aims This study employs multisource satellite remote sensing data to evaluate the damage to vegetation on Hainan Island following the 2024 super typhoon “Yagi”. By investigating the relationship between typhoon trajectory and vegetation impairment, we aim to establish scientific foundations for post-disaster restoration.

Methods Through analysis of normalized difference vegetation index (NDVI) from Sentinel-2 combined with spatial overlay analysis of typhoon trajectories, this research elucidates the spatiotemporal difference of vegetation response dynamics and damage mechanisms.

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 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 diverging 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 biome-dependent: the damage sensitivity is highest in mangroves, followed by treecover > shrub > grassland > cropland > bare land/sparse vegetation; the resilience also follows a similar trend, with mangrove > forestland > cropland > grassland、shrub > bare land/sparse vegetation. Overall, seasonal fluctuations are a significant influencing factor for the continuous decline of vegetation NDVI, with a contribution of 56.20%, while typhoons are an important driver of the decrease of NDVI, with a contribution 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.

Aims Temporary rivers are important ecological corridors and biological refuges in arid regions, but the interactive effects of altitude and temporary rivers on plant community structure and distribution in arid regions remain unclear. This study focuses on the Xitugou 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 temporary rivers channel, and explores whether there are interactive effects between temporary rivers and altitude gradients on plant communities.

Methods The Mann-Whitney U test was used to compare the differences in plant community characteristics between the upstream and downstream of the temporary rivers. A multi-level mixed-effects model was employed to analyze and investigate the interactive effects of the river and altitude on the plant communities. 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 temporary rivers broke through the vertical zonation distribution of species under the water and heat limitations of the arid area. They did not affect the upper limit of species distribution in both river basins, but increased species richness (the total species richness within the river was 1.9-2.7 times that of the outside) and significantly reduced the lower limit of species distribution in the Xitugou river channel. 2) The Mann-Whitney U non-parametric test showed that the average plant height and crown width inside both river channels were significantly higher than those outside. In the Xitugou area, vegetation coverage was significantly greater inside the river channel than outside, whereas in the Daquan River area, plant density was significantly greater outside the river channel than inside; other community characteristics showed no statistically significant differences. 3) As the altitude increases, the average height and average crown width of plants inside and outside the river channel decreased, while the vegetation coverage and plant density increased. Moreover, the decrease or increase in the outside river channel was more significant. 4) The mixed-effects model indicates that the changes in vegetation coverage, plant density, and community structure depend jointly on altitude and river location. The average height is mainly influenced by altitude, reflecting the nonlinear regulation of hydrological and geomorphic processes on community formation in different altitude zones. As key ecological refuges in arid regions, temporary rivers, together with altitude, shape plant community structure and spatial distribution patterns.

Aims Rheum tanguticum is a well-known medicinal plant in China. This study evaluated the adaptability of its ex-situconservation based on biological characteristics, ecological stoichiometric characteristics, and medicinal components, with the aim of providing a theoretical basis for resource conservation, introduction and reintroduction of R. tanguticum.

Methods Based on investigation of wild and ex-situ conserved populations, independent samples t-test were used to analyze the differences in seed germination rate, soil nutrients content, plant leaf traits, photosynthetic parameters, ecological stoichiometric characteristics, nutrient resorption efficiencies, and root medicinal component contents of R. tanguticum between wild distribution area in Liupan Mountains and the ex-situ conservation area, in order to assess its adaptability to ex-situ conservation.

Important findings Rheum tanguticum in the ex-situ conservation area reproduced normally, and its seed germination rate did not differ from that in the wild populations. There were no significant differences in leaf traits, photosynthetic parameters, ecological stoichiometric characteristics, and their ratios between the two habitats, while the mean nitrogen phosphorus ratio was less than 14 at both sites. The carbon nutrient resorption efficiency did not differ significantly between the two habitats, whereas nitrogen and phosphorus resorption efficiencies showed significant differences. The contents of both free anthraquinone and total anthraquinone in roots from the ex-situ conservation area were significantly higher than those from the wild distribution area, meeting the standards of the Pharmacopoeia of the People’s Republic of China (2025 edition). Furthermore, a total of 3 275 metabolites were identified in the roots from both the wild and ex-situ conservation areas, including 1 029 non-significantly different metabolites and 2 246 differential metabolites. There were no significant differences in the chemical classification and enrichment pathways between the non-differential and differential metabolites, indicating the stability of the synthesis and regulation pathways of key medicinal components. In addition, principal component analysis showed significant differences in soil nutrient status and plant water physiological status between the ex-situ conservation area and wild distribution area. Correlation analysis showed that the soil pH was significantly negatively correlated with the soil organic carbon content, and that the soil available nitrogen content was significantly negatively correlated with relative water content of the leaves, and that the nitrogen content of the leaves was significantly negatively correlated with the phosphorus content, and that the soil available phosphorus content was significantly negatively correlated with the contents of free anthraquinone and total anthraquinone in roots. Ex-situ conserved R. tanguticum exhibited good growth performance, maintains stable medicinal quality, and showed successful adaptation to the ex-situ habitat in Liupan Mountains.

Aims The survival and growth of woody plant seedlings are regulated by a complex set of environmental factors. However, it remains unclear how the forest canopy affects understory herbaceous cover and microclimate, and how these in turn shape seedling survival and growth.

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 influences the survival of seedlings of the three wild fruit tree species by regulating understory microclimate and herbaceous cover. Among these factors, herbaceous cover is an important determinant of seedling survival, exerting negative effects on seedlings of M. sieversii and P. armeniaca, but a positive effect on J. regia seedlings. In addition, the key factors limiting seeding growth varied among species. M. sieversii seedling growth was mainly affected by soil pH and herbaceous cover. Juglans regia seedling growth was primarily associated with herbaceous cover and mean temperature of the growing season, whereas P. armeniaca seedlings growth was mainly constrained by mean temperature of the growing season. In conclusion, the forest canopy regulates the survival and growth of wild fruit tree seedlings through multiple direct and indirect pathways, resulting in species-specific responses to biotic and abiotic factors. Therefore, conservation and restoration of the Tianshan wild fruit forests should account for these differential responses and adopt targeted habitat management measures.

Aims This study aims to elucidate the intra-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 sp.ecies in Shenyang and the broader Northeast China region.

Methods This study employed the micro-core technique to monitor the radial growth dynamics of two landscape tree species, Picea koraiensis and Phellodendron amurense, across two consecutive growing seasons (2023-2024) in urban area of 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 intra-annual growth duration was quantified as 176 d for Picea koraiensis and 168 d for Phellodendron amurense, respectively. (2) Early warming and precipitation at the onset of the growing season promote the initiation of cambial activity. In contrast, the timing of growth cessation was independent of the timing of cambial reactivation. Temperature was identified as the predominant environmental factor governing the radial growth dynamics of both species. This research provides a systematic characterization of the spatio-temporalpatterns of xylem development (xylogenesis) and the associated response mechanisms to environmental cues in Picea koraiensis and Phellodendron amurense within Shenyang’s urban ecosystem. The findings provide a reference for research on intra-annual growth dynamics as well as the cultivation and maintenance of urban landscape trees in Shenyang and the broader Northeast China region.

Aims Clarifying the response mechanisms of water use efficiency (WUE) in plantation forests to key hydrological drivers can provide a scientific basis for optimizing stand management and enhancing water regulation and carbon sequestration functions.

Methods To address the unclear response mechanisms of water use efficiency at different scales in plantation ecosystems to key hydrological drivers, this study focuses on a typical Platycladus orientalis plantation ecosystem in the mountainous region of Beijing. Based on eddy covariance observations and the Transpiration Estimation Algorithm (TEA) model for evapotranspiration partitioning, ecosystem scale WUE (WUE_ET) and canopy scale WUE (WUE_T) were derived to analyze their dynamics and the regulatory mechanisms of water-related factors.

Important findings 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 temporal 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 showed significant negative sensitivities to VPD, primarily due to VPD-induced increases in evapotranspiration (ET) and transpiration (T), 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 different VPD quantiles, both WUE_ET and WUE_T showed weak sensitivity to SWC, mainly 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 advances our understanding of plant water-use mechanisms, with significant implications for informing drought resistance strategies and ecohydrological processes.

Methods This study used Koelreuteria paniculata, Juniperus chinensis, and Pinus tabuliformis as model species (with mean heights of 2.42, 1.97, and 2.11 m, and basal diameters of 7.46, 5.85, and 6.53 cm, respectively) for controlled pot experiment with soil and weathered bedrock layers and 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 layers, along with controlled water exchange at their interface. Soil moisture sensors were deployed to monitor hydrological dynamics in these layers, and thermal dissipation probes (TDP) to quantify water uptake rate. Strategic sampling of plant xylem, soil, and weathered bedrock was conducted for hydrogen and oxygen stable isotope compositions (δD 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) Water uptake of all species showed a consistent pattern of an initial decrease followed by an increase over time 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. (3) The contribution rate of bedrock water to water uptake of all species increased significantly with drought progression. The range of contribution 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 adaptation strategy of exploiting bedrock moisture to mitigate drought, providing practical insights for selecting resilient species and guiding water resource management in arid regions.

Aims The elemental composition of plant leaves, stems, and roots is a key indicator of plant adaptive strategies and provides important insights into plant-environment interactions. It is essential to clarify the relationships among multiple elements in different organs of plants in arid regions and their responses to environmental factors, in order to understand plant resource allocation strategies and adaptive mechanisms.

Methods In this study, 20 plant species from eight sites in Baijitan, Lingwu, Ningxia, were investigated. A total of 77 individual samples were collected, and the contents of carbon (C), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) in leaves, stems, and fine roots were measured.

Important findings (1) Carbon concentrations in leaves were significantly lower than those in stems, whereas N, P, K, Ca, and Mg concentrations in stems and fine roots were significantly lower than those in leaves. (2) The variability of concentrations in leaves, stems, and fine roots decreased with increasing mean concentrations among these elements. (3) Network analysis showed that the overall network parameters, including edge density, average path length, diameter, average clustering coefficient, and modularity, were 0.40, 1.75, 4.00, 0.59, and 0.11, respectively, with 54 element-element pairs showing significant correlations. (4) Leaf K and stem C contents exhibited the highest values of degree and closeness centrality, serving as hub elements in the network. (5) Leaf N, K, and Mg, stem N, and fine-root C, P, and K showed significant responses to soil factors. Overall, this study systematically revealed the multi-element network structure of leaves, stems, and roots in plants from an arid area and explored the differential responses of organ-level elemental traits to soil factors. These findings provide new empirical evidence for understanding plant ecological adaptation strategies from a perspective of multi-element integration and highlight the importance of incorporating key elements, such as K, in studies of arid ecosystems.

Aims Ecological restoration in fragile dry-hot valleys remains a critical challenge. Although vegetation restoration is known to improve degraded soils, the long-term effects of different restoration approaches (artificial vs natural) on soil nutrient dynamics and stoichiometric ratios across altitudinal gradient remain poorly understood.

Methods We examined decade-long changes in soil properties (pH, moisture), nutrient content (carbon (C), nitrogen (N), and phosphorus (P)) and stoichiometric ratio (C:N:P) in a degraded savanna ecosystem in the dry-hot valleys of Yuanmou, Yunnan, under contrasting restoration treatments (artificial plantations vs natural regeneration) at altitude gradient.

Important findings Both restoration approaches significantly enhanced soil moisture and nutrients levels compared to degraded controls, though seasonal variability was pronounced. Restoration type differentially influenced nitrogen forms: artificial restoration favored NO- 3-N accumulation, while natural restoration promoted NH+ 4-N. Treatment efficacy was elevation dependent. Mid elevation: Acacia confusa plantations showed more conducive nutrient accumulation, whereas in high-elevation Leucaena leucocephala plantations were effective. Soil stoichiometric ratios revealed clear treatment at different elevation interactions. The natural restoration exhibited significantly higher C:N (17.95) and N:P (13.08) during the dry season at high elevations. The Leucaena leucocephala plantations at mid-elevations was significantly lower C:N ratios (9.96 and 9.85 in dry and rainy season, respectively. In general, natural restoration was more effective in soil nutrients accumulation than artificial restoration. We recommend prioritizing natural regeneration, with artificial restoration employing elevation-specific species selection (A. confusa at mid-elevations, L. leucocephala at higher elevations). These findings provide actionable insights for restorating degraded dry-hot valleys ecosystems.

Aims The rhizosheath is a specialized plant-derived, root-associated structure that facilitates plant adaptation to heterogeneous soil environments while recruiting distinct microbial communities. These microbial communities enhance nutrient uptake by plant roots and improve soil physicochemical properties, thereby contributing to the stability and functioning of soil ecosystems. However, the interactions between rhizosheath microbial communities and key soil environmental factors remain poorly understood.

Methods This study investigated the perennial grass Stipagrostis pennata inhabiting the Gurbantünggüt Desert. Using high-throughput sequencing, we characterized microbial community features in the rhizosheath and bulk soil and constructed co-occurrence networks to explore the relationships among community diversity, network complexity, stability, and soil factors.

Important findings Results showed that Ascomycota and Basidiomycota were the dominant fungal phyla in both rhizosheath and bulk soil environments; however, significant compositional differences were observed at the bacterial phylum and genus levels, as well as at the fungal genus level. Compared with bulk soil, the rhizosheath displayed significantly higher microbial α-diversity, β-diversity, network complexity, and stability. Specifically, bacterial and fungal community complexity in the rhizosheath increased by 171.29% and 301.35%, respectively, while stability increased by 18.46% and 51.02%, respectively. Linear regression analyses showed that microbial diversity was significantly and positively correlated with network complexity and stability. Moreover, results from the random forests and Mantel tests indicate that, compared to bulk soil, the presence of rhizosheath enhances the explanatory power of soil factors for microbial communities, with this effect being more pronounced in bacterial communities. In summary, this study provides new theoretical insights into the role of rhizosheaths in supporting desert plant adaptation and offers a scientific basis for desert vegetation conservation and ecological restoration.

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 grades was carried out, which can help to formulate reasonable restoration strategies.

Methods In this study, the changes in soil physicochemical properties and microbial community structure of artificial Haloxylon ammodendron forests under different degradation levels were analyzed in order to clarify the response 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 relative abundance of Actinobacteriota, Chloroflexi and Acidobacteriota in bacteria increased significantly with the deterioration of forest land, while the relative abundance of Basidiomycota in fungi increased and then decreased, and the relative abundance 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 contents were the main factors affecting the composition of soil bacterial communities in artificial Haloxylon ammodendron forests, while pH of soil, total nitrogen and water contents 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) and is listed among China’s first batch of priority protected species. Difficulties in population regeneration and unclear mechanisms of endangerment highlight an urgent need for systematic community ecology research to support its scientific conservation. Based on examinations 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 restricted to the Minshan, Qionglai and Daba Mountain ranges, with 15 confirmed extant populations (an increase of nine compared with previous records), a vertical distribution range of 2 365-2 936 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 with mixed tropical elements. (3) TWINSPAN classification divided these communities into six association groups and ten associations, indicating that C. palangshanense can occur as a companion species across various coniferous forest types. (4) It exhibits an extremely low proportion 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 characteristics and severe survival threats faced by C. palangshanense, providing key scientific evidence for developing in situ conservation, habitat restoration, and artificial propagation strategies.