：Soil ciliates, crucial components of grassland ecosystems, serve as sensitive bioindicators of soil health and disturbance. This study investigates ciliate communities across four grassland use types on the Qinghai-Tibetan Plateau (QTP): seasonal and continuous grazing in natural grasslands (SGG and CGG), artificial perennial Elymus nutans Griseb. grasslands (PEG), and artificial annual Avena grasslands (AAG). Using live observation techniques, we identified 114 ciliate species from 10 classes and 21 orders, with Haptorida and Sporadotrichia emerging as dominant groups. Our findings reveal that grazing grasslands harbor greater endemic ciliate species richness compared to AAG. SGG and CGG exhibited significantly higher ciliate diversity (Shannon, Simpson, and Margalef indices) than other use types, while PEG and SGG supported higher ciliate abundances. Low Jaccard similarity indices between grassland types indicate distinct ciliate communities, reflecting management-induced environmental heterogeneity. Redundancy analysis identified above-ground biomass and soil pH as primary drivers of ciliate community structure. Notably, seasonal grazing (SGG) promoted the highest ciliate diversity, suggesting its potential as a sustainable management practice for maintaining soil health on the QTP. This research provides crucial insights into the relationship between land management and soil microbial diversity in high-altitude grasslands. Our findings support the implementation of moderate grazing practices to enhance soil quality and ecosystem resilience on the QTP, with implications for sustainable management of similar ecosystems worldwide.

Different grazing practices can have varying impacts on soil properties and soil microbial communities, which are critical for maintaining productivity and functions of grasslands and the overall ecosystem. The Qinghai-Tibetan plateau (QTP) is the largest high-altitude grazing region on earth, and has three different grazing practices, including seasonal grazing (SG), continuous grazing (CG), and exclosure grazing (EG) for 10 years. Vegetation, soil properties from two different depths (0-0.15 and 0.15-0.30 m) and soil microbial communitiesin the surface soil layer (0-0.15 m) were measured in triplicate plots within each grazing practice. The soil conditions in the SG site were the best, the CG site was the worst, while the EG site was intermediate. Dry aboveground biomass, soil organic carbon, total nitrogen, and total phosphorus content under SG were 838 g/m2, 20.73g/kg, 1.74 g/kg, and 0.20 g/kg, respectively, and under CG were 8.80 g/m2, 8.07g/kg, 1.07 g/kg, 0.16 g/kg, respectively. There was no significant difference in the α-diversity of soil bacteria and fungi among the three grazing practices. However, the bacterial communities were significantly different from each other; only the fungal community under EG was significantly different from the other grazing practices. While the relative abundance of Basidiomycota under SG was significantly higher than that under EG, no difference was observed in the relative abundance of Ascomycota, Zygomycota, and unclassified_k_Fungi among the three grazing practices. Compared to SG, CG and EG significantly increased the relative abundance of Actinobacteria, Gemmatimonadetes, Verrucomicrobia, and Nitrospirae, but decreased the relative abundance of Proteobacteria and Bacteroidetes.

Drought, a natural hazard, greatly damages environment, agriculture, hydrology and thus, economy and our society at large. The national-scale variation and propagation characteristics of different types of droughts are critical for developing strategies and policies, while information is limited in China. This research investigated the evolution and propagation characteristics of three types of droughts using standardized indices; Standardized Precipitation Index (SPI), Standardized Soil Moisture Index (SSI) and Standardized Runoff Index (SRI) representing meteorological, agricultural and hydrological droughts based on precipitation (PPT), soil water storage (SWS) and baseflow-groundwater runoff (BGR), respectively at multi-timescales in different sub-regions of mainland China over 1948-2010. The most appropriate probability density distributions of PPT, SWS and BGR were selected for the calculation of drought indices and wavelet analysis was used to reveal their periodical characteristics. Modified Mann-Kendall trend test was used to compare the trend among drought indices. Pearson correlation coefficients were calculated to identify the lags of SPI with SSI and SRI. In general, SPI showed an agreement with the historical severe or extreme drought events at different sub-regions. The main periods of SSI were closer to SPI than SRI, indicating stronger connections of agricultural drought with meteorological drought. A weaker connection between meteorological and agricultural/hydrological droughts at shorter timescales was observed in northwestern arid and semi-arid regions. The propagation from meteorological to agricultural or hydrological droughts were well denoted by the lagged time (months) from SPI to SSI or SRI at a timescale ranged from 0 (mostly located in south China) to 5 months (mostly located in northeastern China) for certain timescale. The study provides crucial information and guidance to the policy makers in developing drought management strategies at regional to national scale and their critical time of action.