黄河源高寒草甸高原鼠兔土丘的土壤风力侵蚀规律

Soil Wind Erosion Law in Ochotona Curzoniae Mound of Alpine Meadow in the Yellow River

为阐明高寒草甸退化区土壤风力侵蚀作用及土壤流失规律,以青海省河南县退化高寒草甸高原鼠兔土丘为研究对象,通过开展野外人工模拟风蚀试验,对不同风速下鼠丘土壤流失量及其养分流失规律进行分析和讨论。结果表明:(1)风蚀作用下土壤流失量均呈先快后慢的变化规律,风速从6.0 m/s逐步增加到12.0 m/s时,土壤流失量增长约6.3倍。(2)风蚀过程中鼠丘高度和直径随风蚀时间的变化较明显,其变化速率与土壤流失速率相对应,且风蚀促进土壤水分的蒸发速率,从而促进鼠丘的土壤可蚀量。(3)鼠丘土壤养分随风速和土壤流失量的增大而增大,即养分流失规律与土壤流失量的变化规律相同,其中土壤有机质、全钾、速效钾和碱解氮的流失量相对较大。研究结果表明风力侵蚀是加剧退化高寒草甸高原鼠兔爆发区土壤流失和养分贫瘠的重要因素之一。

In order to clarify the wind erosion effect and soil loss law in the degraded area of alpine meadow,the outbreak area of the Ochotona Curzoniae mound in the degraded alpine meadow of Henan County in Qinghai Province was taken as the research object.The field artificial simulated wind erosion tests were carried out with different wind speeds.The law of the soil loss and nutrient loss of the rodent mound was analyzed and discussed.The results showed that:(1) The amount of soil loss under wind erosion take a tendency of initied fast followed by slow.When the wind speed was gradually increased from 6.0 m/s to 12.0 m/s,the amount of soil loss increased by about 6.3 times.(2) The heights and diameters of the rodent mound were significantly different with time during the wind erosion process.Their changing rates corresponded to the rates of soil loss.Wind erosion promoted the evaporation rates of soil moisture,thereby promoting the soil erosion of the rodent mound.(3) The soil nutrient loss in the Ochotona Curzoniae mound increased with the increases of wind speed and soil loss,indicating that the law of nutrient loss and soil loss were the same.The loss of organic matter,total potassium,available potassium and alkali nitrogen was relatively large.These findings show that wind erosion is one of the important factors that aggravate the soil loss and nutrient infertility in the Ochotona Curzoniae outbreak area of degraded alpine meadows.