草原矿区土壤环境损害基线评估判定的应用研究——以内蒙古草原矿区为例

草原生态环境损害评估鉴定中，土壤基线是重要的评价标准。如何确定土壤基线，寻找适宜的基线判定方法，进而判定草原土壤的受损害程度，已成为草原生态系统损害评估鉴定、生态系统保护及修复工作中的关键。基于科学、务实、准确的原则，对内蒙古2个草原矿区土壤的总有机质（TOM）、N、P、K含量进行采样分析，采用历史数据法、参考点位法和统计点位法来判定土壤基线。结果表明，胜利矿区土壤养分均值与参考点位法基线值差异较小，采矿对胜利矿区土壤养分含量未见直接的影响。宝日希勒矿区土壤中TOM含量均值明显低于3种方法得出的基线值，N、K均值与参考点位法基线值相似，P均值位于3种基线值之间。可见采矿对宝日希勒矿区土壤中TOM的含量造成了直接影响，对N、P、K含量未见直接的影响。最适宜该地区的方法取决于样本质量和评估尺度，建议以参考点位法为主，历史数据法和统计点位法作为验证工具，3种方法共同使用。

Baseline assessment of grassland soil in mining area: A case study in the Inner Mongolia grassland

Soil baseline is regarded as an important indicator in the assessment of grassland ecological and environmental damage. How to determine the soil baseline, find the suitable method, and determine the damage degree of soil have become the key point of grassland protection and ecological assessment. In this study, we selected three methods to determine the soil nutrients baseline (total organic matter (TOM), N, P, and K) in Shengli mining area of Xilin Gol Grassland and Baorixile mining area of Hulun Buir Grassland in northern China based on practical and accurate criteria. The soil nutrients'' baselines were analyzed by historical data method, reference site method, and the statistical method. The results showed relatively small difference between the soil nutrient level of Shengli mining area and its soil baseline of reference site method. The content of K was disturbed by mining but its average had not decreased significantly compared with the baseline values, so mining activities had no direct impact on the soil nutrient level of Shengli mining area. The average content of TOM in the soil of Baorixile mining area was obviously lower than the baselines of the three methods. The average contents of N and K were similar to the baseline of reference site method, and the average content of P was in the range of three baselines. As a result, mining had a direct impact on the content of TOM in the soil of Baorixile mining area, but no direct impact on the content of N, P, and K. All three methods could be used to determine the grassland soil baseline, but the results were different, and each method had its own advantages and disadvantages. Historical data method reflected the actual historical state of the grassland in the study area, and could be used as a comparative standard for the assessment and identification of ecological environment damage, but it lacked consideration of natural evolution and other factors. Reference site method was most effective when areas with the same natural conditions and ecological function were available, which could be very hard to find in reality. The calculation process of statistical method was prompt and convenient, and its utilization of data was quite high, whereas it was not suitable for the grassland area with high degree of human interference. The most appropriate method for baseline determination may depend on the availability of sample data and evaluation scale. Reference site method would be preferred, while historical data method and statistical method can be the substitutes. It is recommended to use multiple methods together to verify the result.