Search

Permafrost degradation has been widely reported on the Tibetan Plateau (TP). However, directly observed evidence of permafrost thawing processes and degradation rates are very limited, although it is expected to be prevalent near the periphery of a permafrost area. Here, we report permafrost changes and disappearance in the Qilian Mountains (northeastern TP) based on three boreholes instrumented along a 100 m transect during 2014–2021. Our results show that permafrost has significantly degraded in the study area: the mean downward thawing rate from the permafrost table was about 0.16 m per year while the mean upward thawing rate from the permafrost base was about 0.23 m per year. We estimate the mean lateral degradation rate of permafrost in this area was ∼4.14 m per year. More dramatically, the 1.5 m thick permafrost layer at one of the boreholes thawed completely between April of 2018 and December of 2019. Our results indicate that changes in climatic condition may have played only a limited role in controlling the active layer thickness in the vicinity of the altitudinal limit of permafrost; moisture content and soil conditions play key roles in site-specific permafrost thawing. This study provides new quantitative insights for understanding changes near the altitudinal limit of permafrost, and we suggest that land surface models or Earth system model studies of the lateral heat exchanges should be implemented in order to better represent permafrost thawing processes.

The Qilian Mountains (QLMs) serve as a vital ecological security barrier in the northwest China, determining the optimal fractional vegetation cover (FVC) of different land-use types is crucial for ecological restoration and protection. Based on the normalized vegetation index, meteorological data, soil data and land-use data, the InVEST model, bivariate spatial autocorrelation and elastic analysis, we calculated the water conservation, soil conservation and carbon storage, analyzed the spatio-temporal distribution characteristics of FVC and ecosystem services (ES) and the correlation between them. This study aims to evaluate the optimal FVC of the different land-use types and vegetation restoration’s effect on it in the QLMs. The results showed that the FVC and ES showed an increasing trend from 2000 to 2020, with a spatial distribution pattern of high values in the southeast and low values in the northwest. There was a significant and positive correlation between FVC and ecosystem service functions (p

In this paper， the ability of CMIP6's 10 global climate models to simulate the historical climate change of Qilian Mountains is tested by using a variety of test parameters.We found that the CESM2-WACCM model has the best simulation effect on projection of climate variation in Qilian Mountains.Therefore， the variation characteristics of temperature， precipitation and humidity in Qilian Mountains from 2020 to 2064 are analyzed under three emission scenarios.They are low， medium and high emission scenario.The results are as follows： （1） In the next half century， the temperature at northern part of Qilian Mountains will be higher， lower at the southern part and higher at both ends， the possibility of heating up is high， the characteristics of warm winter are more obvious than that of warm summer.Comparing the future rise amplitude of Qilian Mountains temperature under different scenarios， it is found that under the high emission scenario， the temperature rises most significantly in winter and summer， while the rise amplitude of medium emission scenario is the lowest.（2） In the future， the precipitation in Qilian Mountains will increase in summer， and the possibility of "humidification" is relatively large.Especially under the scenario of high emission， the intensity of "humidification" is the highest in the eastern part of Qilian Mountains， and it is consistent with the water vapor convergence area shown by the divergence of water vapor flux.（3） The future water vapor variation in Qilian Mountains expressed by atmospheric specific humidity show that atmospheric humidity is more likely to increase in summer， and the variation in southern Qilian Mountains is obvious than that in Northern Qilian Mountains， especially in the scenario of high emission， the East will become more humid in the future， which is consistent with the increase of future precipitation in Qilian Mountains.

Long time series of annual land cover with fine spatio-temporal resolutions play a crucial role in studying environmental climate change, biophysical modeling, carbon cycling models, and land management. Despite a strong consistency exhibited by several publicly available medium to fine resolution global land cover datasets, significant discrepancies exist at the regional scale; moreover, only every 5/10 year land cover were available. Consequently, high-quality annual land cover datasets before 2000 are unavailable in China. In this study, we proposed a deep learning-based method by integrating multiple remote sensing data from different platforms with historical high spatial resolution land cover datasets (CNLUCC) to derive the 30 m annual land cover maps from 1980 to 1990 for Qilian Mountain. First, the super-resolution generative adversarial network models for upscaling the 5.5 km AVHRR NDVI to 250 m were established by employing the AVHRR and MODIS NDVI data with the same year as input, and the early time series AVHRR NDVI data were subsequently upscaled to 250 m through the above models. Second, the breaks for the additive seasonal and trend (BFAST) change detection algorithm was applied to the upscaled time series NDVI data to detect the change time of different land cover types. Third, the CNLUCC data in 1980 and 1990 were updated to annual land cover datasets from 1980 to 1990 and the annual mapping results provided insights into the dynamic processes of urbanization, deforestation, water bodies, and farmland from 1980 to 1990. Finally, comprehensive analysis and validation were carried out for evaluation and an overall accuracy of 77.26% for the land cover product in 1986 was achieved.

The Qilian Mountains are situated on the northeastern margin of the Tibetan Plateau and serve as the leading edge of the plateau's northeastward expansion. The Menyuan Basin, characterized by typical basin landforms, provides valuable insights into the region's neotectonic activity and geomorphic evolution. As a representative mountain basin located in the central part of the Qilian Mountains, the Menyuan Basin's development pattern and geomorphic features are closely linked to tectonic activity. This study aims to investigate the variations in tectonic activity and their underlying causes along the north margin fault and different zones of the Menyuan Basin. To achieve this, 30 m resolution digital elevation model (DEM) data and ArcGIS spatial analysis technology were employed to extract the hypsometric integral (HI) and hypsometric integral curve (HC) of 15 rivers that traverse the northern edge of the basin. Subsequently, kriging interpolation was utilized to obtain the spatial distribution characteristics of HI within the basin. The findings reveal that HI values generally exhibit higher values on the western side and lower values on the eastern side of the Menyuan Basin, with the turning point (Laohugou) of the northern fault at the Menyuan Basin serving as the boundary. By combining the distribution of HI with field investigation results of active structures, it is observed that the eastern fault has extended into the basin's interior, giving rise to a series of active reverse fault–fold zones. This phenomenon may be attributed to changes in fault trends and the presence of northeastward faults. Additionally, a high HI anomaly is detected near Qingshizui Town in the basin's interior. Based on previous electromagnetic detection results, it is inferred that a buried fault exists within the basin. Furthermore, the study demonstrates that most rivers exhibit peak fluctuations in the stream length–gradient index (SL) at a specific position upstream of the main fault, indicating a strong correlation between the location of SL fluctuations and the position of the fault intersecting the river. In other words, tectonic activity can exert a significant influence on SL. Abnormal fluctuations near lithological transitions may suggest that local changes in lithology also impact the stream length-gradient index. The comprehensive analysis underscores the substantial differences in geomorphic development between the eastern and western sections of the northern edge of the Menyuan Basin, primarily controlled and influenced by the active structures in this region. Moreover, the aforementioned geomorphic parameters serve as sensitive indicators for evaluating tectonic activity.

Desertification poses a serious threat to ecosystem health, and with global changes, the variability and uncertainty of ecological functions in semi-arid alpine regions are increasing. A pressing issue is quantifying how desertification affects the soil system functions in these areas. However, empirical evidence is still lacking in exploring the interaction between desertification degradation gradients and soil functions under natural conditions by coupling soil physicochemical properties, soil microbiota, and vegetation. For this purpose, we conducted a survey sampling of soil and vegetation at five sites with no, light, moderate, severe and extremely severe desertification in Qinghai Area of Qilian Mountains National Park, China. We introduced a new concept soil health stability (SHS) to represent the actual health status of soil systems in semi-arid alpine regions and assessed the impact of desertification on this stability. We observed that the intensification of desertification has led to a significant decrease in soil organic matter, relative abundance of soil microorganisms, and plant factors. The contributions of plant factors and soil microbiota to SHS showed a negative correlation with the degradation gradient. SHS varied across different degradation gradients, rather than following a single linear relationship, with a relatively rapid decline in the transition from non-desertification to moderate desertification. Our work emphasizes that the coupled contributions of soil physicochemical properties, soil microbiota, and vegetation to SHS. It calls for intensified prevention and treatment of mild and moderate desertification, while providing new methods and deeper scientific understanding for accurately evaluating soil system functions in semi-arid alpine regions.

The linear regression， Mann-Kendall trend test and Morlet wavelet transform were used to make a detailed analysis on the temporal dynamics and spatial patterns of temperature and precipitation.The temperature and precipitation monitoring data from 12 meteorological stations in the northern slope of Qilian Mountains and its adjacent areas during the period from 1965 to 2018.The results revealed that： （1） The multi-annual mean， maximum and minimum temperatures fluctuated with increase rates of 0.33 ℃·（10a）-1， 0.44 ℃·（10a）-1 and 0.21 ℃·（10a）-1， the temperature changed dramatically in 1998.The multi-annual mean and maximum precipitation fluctuated with increase rates of 4.28 mm·（10a）-1， 16.98 mm·（10a）-1， while the minimum value fluctuated with decrease rates of -4.30 mm·（10a）-1， there was a sudden change in precipitation from less to more in 1971 and 1994.The seasonal variation trend of temperature and precipitation was consistent and continued to rise， and there has a significant increase feature in winter.The interdecadal evolution of the two shows an increasing trend in the 1990s.（2） On the whole， the temperature and precipitation decreased from southeast to northwest， forming a spatial pattern with Zhangye and Gaotai as the dividing line， the temperature and humidity increased faster in the east， and the temperature and humidity increased slower in the west.The overall climate showed a warming and humidity trend.（3） The annual mean temperature has a strong period of 13-year and a period of 6a and 27-year in the scale of 54-year， and there are strong significant periods of 8-year and 20-year and small-scale change periods of 2-year and 27-year.

To explore the morphological differences among different geographic populations of Gymnocypris chilianensis, 29 measurable traits and 13 landmarks on 191 individuals of 10 geographic populations were collected from three different inland water systems, i.e., Shiyang River, Heihe River, and Shule River, in Qilian Mountains, China. Multivariate statistical methods were used to compare morphological differences among the populations, such as principal component analysis, cluster analysis, discriminant analysis, and visual analysis of landmark data. The results showed that: (1) There were significant morphological differences between groups of G. chilianensis. The Shiyang River basin differs significantly from populations in the other two basins. (2) The inter-population differences were mainly reflected in the length of the trunk and tail, and the difference between trunk and caudal fin had the most obvious characteristics, proving the tail being the main direction of variation. This research provides an effective theoretical basis for the fine management and accurate protection of G. chilianensis germplasm resources. [ABSTRACT FROM AUTHOR]

Precipitation around the Qilian Mountains has close relationship with developing of large-scale circulation system and orographic cloud forced by complex topography in this region.The present work compares synoptic pattern and relevant physical parameters as well as development mechanism of two type precipitation processes around the Qilian Mountains such as CASE1 which occurred during July 19 -20， 2018 and CASE2 which occurred on August 28， 2018 with observed data and high resolution data from WRF model version 3.8.1.Synoptic analyses show that CASE1 precipitation process is the result of interaction between favorable large-scale and local topography， CASE2 is mainly a precipitation process induced by local topography and no significant large-scale circulation system in this process.Results of diagnosis analyses indicate that CASE1 has characteristics such as sufficient water vapor supply， obviously unstable of the stratification， high effective convective energy （1064.84 J·kg-1）， strong vertical shear of the horizontal wind （27.6 m·s-1）， Richardson number （Ri） less than 0 and strong vertical ascending motion et al.before precipitation， which caused the formation of larger area and persistent precipitation process.However， the stratification in CASE2 is more stable than that in CASE1， and the maximum of MCAPE （546.15 J·kg-1） is about half of that in CASE1， the maximum horizontal wind vertical shear （17.37 m·s-1） is far less than that of CASE1， and Richardson number is greater than 0 in the precipitation stage， which means it is a weak convective precipitation process and precipitation rate is relatively smaller as well as and relatively short duration.

Based on ERA5 reanalysis data and CLDAS land grid precipitation data from the National Meteorological Information Center， a systematic WRF numerical simulation and precipitation mechanism diagnosis of a typical systematic precipitation process in the Qilian Mountains are carried out in this paper.The dynamic diagnosis results of the circulation background field show that the interaction between the mesoscale upper trough system and the local lower flow around and flow over provides important dynamic conditions.The mesoscale dynamic uplift in front of the trough caused by the development of the upper trough determines the distribution of the heavy precipitation belt during the precipitation process， while the lower flow around and flow over provide direct dynamic conditions for local heavy precipitation.The further diagnosis results of water vapor transport and budget show that the water vapor source of this precipitation mainly comes from the Sichuan Basin.The flow around will transport abundant water vapor for the precipitation area in front of the windward slope， and the flow over will promote the reverse gradient transport of water vapor along the terrain height and converge near the precipitation center.In the stage of heavy precipitation， the vertical transport of water vapor contributes the most to the water vapor budget， followed by the convergence of water vapor， and the local variation of water vapor can be basically ignored.Finally， the diagnostic results of atmospheric stratification characteristics show that when both atmospheric dynamic conditions and water vapor conditions are conducive to precipitation， combined with the enhancement of the instability of low and medium tropospheric stratification， it is easier to trigger convection and enhance precipitation in front of the windward slope.

Qilian Mountains (QM) is an important ecological security barrier in China and has been significantly affected by climate change, it is therefore of great importance and necessity to project its future climate change using high-resolution climate models because of mountainous areas in the QM and relatively few targeted simulation analyses. In this study, we used the simulations of the regional climate model REMO with 25 km spatial resolution, driven by three different global climate models (MPI-ESM-MR, NorESM1-M, and HadGEM2-ES), to evaluate how annual and seasonal mean surface air temperature and precipitation in the QM are likely to change for three future periods (2011–2040, 2041–2070, and 2071–2100) under two representative concentration pathways (RCP2.6 and RCP8.5). The REMO model, shows noticeable cold and wet biases compared to observations for the reference period (1971–2000) and air temperature simulation outperforms precipitation simulation. The REMO simulations exhibit a warm and wet centre around lake, indicating that the simulation are likely influenced by lake. Projections under RCP2.6 show regional warming reaching 1.74 °C during 2011–2100, characterized by an initial increase and a decrease afterwards. Under RCP8.5, air temperatures increase monotonously from 2011 to 2100, with a warming magnitude of 5.36 °C for 2071–2100 relative to 1971–2000. The overall change in regional-average annual precipitation is not evident during 2011–2100, with some increases or decreases in certain time periods. In the 2071–2100 both the strongest warming and precipitation increase are projected to occur in winter under both scenarios, while precipitation in summer and autumn is projected to decrease in the east of the QM for the three future periods. The results suggest that the QM is likely to experience drought conditions in warm seasons in the future, which could impact agricultural and livestock production.

Background: Mining activities are known to exert significant effects on the structure and function of grassland ecosystems. However, the role of mining grasslands restoration in altering the plant community and soil quality remains poorly understood, especially in alpine regions. Here, we investigated species diversity in grasslands with dynamic changes and different restoration levels in the Tianzhu alpine mining area locating in the Qilian Mountains.Methods: The plant community structure and species composition of the grasslands with different restoration levels were analyzed by the sample method. We used five different restoration levels: very low recovered degree (VLRD), low recovered degree (LRD), medium recovered degree (MRD), and high recovered degree (HRD), and selected natural grassland (NGL, CK) as the control.Results: Plant community structure and species composition were significantly higher than those under the VLRD in the Tianzhu alpine mining area (p < 0.05), with HRD > MRD > LRD > VLRD. There were 11 families, 18 genera, and 17 species of plants, mainly in the families of Leguminosae, Asteraceae, Gramineae, Rosaceae, and Salicaceae; among them, Salicaceae and Gramineae played a decisive role in the stability of the community. The ecotype community showed that perennial herbaceous plants were the most dominant, with annual herbaceous plants being the least dominant, and no tree and shrub layers were observed; the dominance index was the highest in VLRD at 0.32, the richness index was the highest in HRD at 2.73, the diversity of HRD was higher at 1.93, soil pH and EC showed a decreasing trend, and SMC, SOC, TN, NO3-N, NH4-N, AN, TP, and AP content showed an increasing trend with the increase of grassland restoration.Conclusion: In summary, with the increase of restored grassland in the Tianzhu alpine mining area, plant diversity gradually increased and plant community structure gradually diversified, which was close to the plant diversity of NGL. The protection of partially VLRD and LRD grasslands in the mining area should be emphasized, and the mine grassland should be used rationally and scientifically restored.

Surface albedo plays a pivotal role in the Earth's energy balance and climate. This study conducted an analysis of the spatial distribution patterns and temporal evolution of albedo, normalized difference vegetation index (NDVI), normalized difference snow index snow cover (NSC), and land surface temperature (LST) within the Qilian Mountains (QLMs) from 2001 to 2022. This study evaluated the spatiotemporal correlations of albedo with NSC, NDVI, and LST at various temporal scales. Additionally, the study quantified the driving forces and relative contributions of topographic and natural factors to the albedo variation of the QLMs using geographic detectors. The findings revealed the following insights: (1) Approximately 22.8% of the QLMs exhibited significant changes in albedo. The annual average albedo and NSC exhibited a minor decline with rates of −0.00037 and −0.05083 (Sen's slope), respectively. Conversely, LST displayed a marginal increase at a rate of 0.00564, while NDVI experienced a notable increase at a rate of 0.00178. (2) The seasonal fluctuations of NSC, LST, and vegetation collectively influenced the overall albedo changes in the Qilian Mountains. Notably, the highly similar trends and significant correlations between albedo and NSC, whether in intra-annual monthly variations, multi-year monthly anomalies, or regional multi-year mean trends, indicate that the changes in snow albedo reflected by NSC played a major role. Additionally, the area proportion and corresponding average elevation of PSI (permanent snow and ice regions) slightly increased, potentially suggesting a slow upward shift of the high mountain snowline in the QLMs. (3) NDVI, land cover type (LCT), and the Digital Elevation Model (DEM, which means elevation) played key roles in shaping the spatial pattern of albedo. Additionally, the spatial distribution of albedo was most significantly influenced by the interaction between slope and NDVI. [ABSTRACT FROM AUTHOR]

An increase in extreme temperature events could have a significant impact on terrestrial ecosystems. Reanalysis temperature data are an important data set for extreme temperature estimation in mountainous areas with few meteorological stations. The ability of ERA5-Land reanalysis data to capture the extreme temperature index published by the Expert Team on Climate Change Detection and Indices (ETCCDI) was evaluated by using the observational data from 17 meteorological stations in the Qilian Mountains (QLM) during 1979–2017. The results show that the ERA5-Land reanalysis temperature data can capture well for the daily maximum temperature, two warm extremes (TXx and TX90p) and one cold extreme (FD0) in the QLM. ERA5-Land’s ability to capture temperature extremes is best in summer and worst in spring and winter. In addition, ERA5-Land can capture trends in all extreme temperature indices except the daily temperature range (DTR). The main bias of ERA5-Land is due to the difference in elevation between the ground observation station and the ERA5-Land grid point. The simulation accuracy of ERA5-Land increases with the decrease of elevation difference. The results can provide a reference for the study of local extreme temperature by using reanalysis data.

Cosmic-ray neutron sensors (CRNS) are a powerful tool for measuring soil moisture on a hectometer scale, and mobile cosmic-ray neutron technology holds significant importance for upscaling soil moisture. However, vegetation strongly affects with CRNS soil moisture measurements. Variations in vegetation over time change how the CRNS is affected, which is more challenging than a stable vegetation cover, particularly during CRNS roving, where one crosses many vegetation covers. To correct vegetation, we hypothesized that Normalized Difference Vegetation Index (NDVI) can represent vegetation hydrogen pools. From 2020 to 2023, at the 74 plots with varying vegetation cover near the Qilian Mountains, the experiments for soil moisture measurements were conducted in shrubs, forests, deserts, farmlands, and grasslands using a Cosmic-ray Neutron Rover. The measured neutron intensity clearly varied across different landscapes, and the calibrated parameter N0 differed among 74 plots. The variations in vegetation cover resulted in low measurement accuracy for CRNS. All three NDVI vegetation correction methods (NDVI-θNDVI method, NDVI-NDVIave method, and NDVI-N0 method) offered by the study could improve accuracy of soil moisture measurements. In the optimal NDVI-N0 method, the relationship between NDVI and N0 was established using a power function y = 373.9 (x + 0.015)−0.136 (R2 = 0.77), which had the capability to decrease the root mean square error between oven-dried and measured soil moisture from 0.093 to 0.032 g g−1 in our study area. Employing NDVI instead of biomass for CRNS vegetation correction can substantially reduce workload and effectively enhance CRNS soil moisture measurements, showing the potential for upscaling soil moisture.

The Qilian Mountains (QLM) act as an "ecological security barrier" in western China, impacting the downstream ecosystems and water resource utilization. However, the hydrological evolution of the QLM during the last millennium remains controversial, and their ecological response to climate change is poorly understood. We present a pH record based on the brGDGTs (branched glycerol dialkyl glycerol tetraethers) of a 14C-dated sediment core from Lake Maozangtianchi in the QLM. We combined this record with element contents determined by scanning XRF and grain size to reconstruct the summer monsoon precipitation variability over the last 900 years. We also reconstructed the history of eco-environmental changes from the total n -alkane contents. On centennial scales, local precipitation exhibited peaks during the intervals of 1100‒1300 CE and 1750‒2000 CE, as well as between 1400‒1750 CE. Additionally, abrupt decreases in precipitation occurred during the transition from the Medieval Warm Period (MWP) to the Little Ice Age (LIA) (1300‒1400 CE). This pattern coherent with other hydroclimatic records from the monsoonal margin of northern China, likely resulted from the combined impact of the El Niño‒Southern Oscillation on tropical Pacific sea-surface temperatures and the meridional shift of the Intertropical Convergence Zone. In addition, a coupled relationship between plant biomass in the Lake Maozangtianchi watershed and fluctuations in monsoon precipitation was observed, with higher plant biomass during 1100‒1200 CE, 1750‒1900 CE, and 1950‒2000 CE, and lower biomass during 1200‒1400 CE and 1900‒1950 CE. However, during 1400‒1750 CE, plant biomass exhibited a minor increasing trend, deviating from its usual correlation with monsoon precipitation. Despite precipitation usually being the primary climatic factor influencing plant biomass in the QLM, during the LIA, nutrients transported by dust and decreased evapotranspiration became pivotal in bolstering plant growth. Our research emphasizes the significant moderating effects of exogenic dust on vegetation changes in alpine ecosystems. [ABSTRACT FROM AUTHOR]

Long time series of annual land cover with fine spatio-temporal resolutions play a crucial role in studying environmental climate change, biophysical modeling, carbon cycling models, and land management. Despite a strong consistency exhibited by several publicly available medium to fine resolution global land cover datasets, significant discrepancies exist at the regional scale; moreover, only every 5/10 year land cover were available. Consequently, high-quality annual land cover datasets before 2000 are unavailable in China. In this study, we proposed a deep learning-based method by integrating multiple remote sensing data from different platforms with historical high spatial resolution land cover datasets (CNLUCC) to derive the 30 m annual land cover maps from 1980 to 1990 for Qilian Mountain. First, the super-resolution generative adversarial network models for upscaling the 5.5 km AVHRR NDVI to 250 m were established by employing the AVHRR and MODIS NDVI data with the same year as input, and the early time series AVHRR NDVI data were subsequently upscaled to 250 m through the above models. Second, the breaks for the additive seasonal and trend (BFAST) change detection algorithm was applied to the upscaled time series NDVI data to detect the change time of different land cover types. Third, the CNLUCC data in 1980 and 1990 were updated to annual land cover datasets from 1980 to 1990 and the annual mapping results provided insights into the dynamic processes of urbanization, deforestation, water bodies, and farmland from 1980 to 1990. Finally, comprehensive analysis and validation were carried out for evaluation and an overall accuracy of 77.26% for the land cover product in 1986 was achieved. [ABSTRACT FROM AUTHOR]

Soil fungi play important roles in nutrient cycling and energy flow in forest ecosystems. To investigate the impact of altitude on soil physicochemical properties and enzyme activity and to reveal the altitudinal distribution pattern of soil fungal communities, this study focused on surface soil at different altitudes (2 400, 2 500, 2 600, 2 700, 2800 m) in the Beishan Forest Farm, Qinghai Province. High-throughput sequencing technology was used to analyze the diversity and richness of fungal communities and explore the main factors influencing the soil fungal community structure. Fifteen phyla, 59 classes, 144 orders, 302 families, and 633 genera of soil fungi were discovered across the five altitudes. At the phylum level, the dominant fungal communities were Ascomycota, Basidiomycota, and Mortierellomycota. The richness index (Ace, Chao index) and diversity index (Shannon index) of soil fungal communities generally increase with altitude. The soil organic carbon content, moisture content, andα-glucosidase activity increase with altitude. The urease activity first decreases, then increases, and then decreases with altitude. Redundancy analysis showed that soil physicochemical properties and enzyme activity jointly explained 81. 23% of fungal community variation, and soil nitrate nitrogen content, total phosphorus content, and pH value were the main influencing factors of soil fungal community richness differences. [ABSTRACT FROM AUTHOR]