1) Data collection method: In April 2018, scientific researchers from the Xinjiang Institute of Ecology and Geography of China Academy of Sciences went to southern, central and central and eastern Tajikistan to conduct systematic surveys and samples on the plant composition, productivity, soil nutrients, soil microorganisms, etc. of the winter, spring, summer and autumn pastures. Through family questionnaire surveys, we learned in detail the composition characteristics and quantity of livestock, grazing methods, family income, grassland protection awareness, etc. Based on comprehensive consideration of the survey results, 17 typical degraded and enclosed grassland sample sites were selected, and a 1m×1m sample square was randomly arranged for plant and soil survey and sampling. 2) Species composition analysis method of grassland plant community: Measure the coverage of vegetation species by visual inspection, select the tallest plant and shortest plant of the same plant, and use a tape measure to measure the height of the plant from the root of a single plant 1- 2 cm away from the ground to the highest point at the top of the plant. Measure the height of the plant, and record the highest and lowest heights of the plant; 3) Grassland above-ground biomass analysis method: Collect the above-ground parts of the plants in the small sample square (the parts above the roots 1- 2 cm from the ground), weigh and record their fresh weight, and then take them back to the laboratory. The fresh grass is dried at a constant temperature of 65 ℃ in an oven for more than 48 hours until the weight does not change. At this time, the dry weight is weighed and calculated as the above-ground dry weight biomass.

Data collection, processing and processing records are based on the "National Technical Specifications for Survey and Evaluation of Ecological Status-Field Observation of Grassland Ecosystem"(HJ 1168-2021). From sample point selection, sample site setting, preliminary preparation for survey, survey sampling, and indoor analysis, the data quality is controlled throughout the process. Data quality control before investigation: Through careful analysis of grassland degradation, 17 representative typical grassland ecosystems were selected. At the same time, a systematic survey and sampling specification plan was formulated, and based on this plan, technical training was provided to all personnel involved in field survey and sampling to reduce human error as much as possible. Data quality control during investigation and sampling: The collection of soil samples shall be carried out in accordance with the soil sample collection specifications, and attention shall be paid to the numbering of standard clear samples to facilitate sample pretreatment and analysis and testing in the laboratory. After completing the investigation of each sample party, investigators immediately checked the original recorded data so that problematic data could be corrected in a timely manner. After the field investigation is completed, investigators and recorders further check the completed sample data and supplement relevant information; the paper version of the data is entered into the computer and then checked again, and the paper data is properly preserved. Indoor analytical testing and post-test data quality control: After the soil samples are brought back to the laboratory, the pretreatment of the samples is quickly completed. Then, according to the experimental schedule and referring to standard analysis methods, the sample testing work is completed on time and with quality. After the test of each indicator is completed, the experimental data will be entered into the computer in time, and at the same time, it will be checked for abnormal values. The compiled data set is first self-checked by the experimenter and then delivered to the experts for final review and revision to ensure the authenticity and reliability of the data set.