高寒草地鼠兔干扰下不同地表类型的土壤属性特征

为探究高原鼠兔(Ochotona curzoniae)活动对高山草甸土壤理化性质和生物活性的影响,以青海省果洛藏族自治州玛沁县为研究区,选取受高原鼠兔影响的草地为研究对象,根据有无鼠兔扰动和有鼠兔扰动下的不同地表特征,将有无鼠兔扰动的地表划分为4种类型,分析了4种地表类型土壤理化性质和生物学性质,并采用主成分分析方法对不同地表类型草地进行土壤质量评价。结果表明:(1)存在鼠兔扰动草地,洞口裸斑处土壤含水率、容重增加,土壤机械组成出现砂粒化发展趋势,土壤速效养分浓度升高,洞口裸斑处土壤碱解氮含量较扰动草地增加了41.31%,有机质含量和阳离子交换量在洞口裸斑处最高。(2)4种地表类型土壤酶活性均有不同程度的差异,蔗糖酶活性在不同地表类型下无显著差异,洞口裸斑处脲酶含量最高为3.31 mg/(d·g),磷酸酶和过氧化氢酶的活性在有鼠兔扰动下的3种地表类型均显著增加。(3)通过对不同地表类型土壤质量进行评价,得分排序为:Ⅲ>Ⅳ>Ⅱ>Ⅰ,鼠兔频繁活动的洞口裸斑处土壤质量较佳。鼠兔扰动对土壤性质影响显著,不同地表类型土壤质量存在差异。因此,鼠兔扰动改变了鼠洞周边土壤性质,使其物理化学性质发生显著变化。研究结果对进一步认识高原鼠兔扰动影响下的草地土壤性质变化具有重要支撑作用,也为青藏高原生态系统的管理与保护提供参考。

Soil Properties of Different Surface Types Disturbed by Plateau Pika in Alpine Meadow

In order to explore the effects of plateau pika(Ochotona curzoniae)activities on soil physicochemical properties and biological activities of alpine meadow, we selected the meadow affected by plateau pika in Maqin County, Qinghai Province as the research area. Four types of meadow soil were sampled according to the different land surface influenced by pika disturbance. The physical and chemical properties and biological properties of four meadow soils were analyzed. And the principal component analysis was used to evaluate the soil quality of different surface types of grassland. The results show that:(1)soil moisture content and bulk density increase due to pika disturbance; nutrient contents increase in the soil due to the influence of pika, organic matter and cation exchange capacity are the highest at the bare spot of the cave;(2)the soil enzyme activities in four types of sites are different; the highest urease content was 3.31 mg/(d·g)at the bare spot of the cave mouth, and phosphatase and catalase increase significantly in all three types of ground surface disturbed by pika; to summarize, the disturbance of pika can alter the physical-chemical properties of the grassland soil in Qinghai-Tibet Plateau;(3)through the evaluation of soil quality of different surface types, the scores are as follows: type Ⅲ>typeⅣ>typeⅡ >type I; the soil quality in the bare spot of the hole where the pika frequently moves is better; the disturbance of pika has a significant effect on soil properties, and there are differences in soil quality among different surface types. The results of this study are of great importance to further understand the effects of plateau pika disturbance on the soil properties of alpine grassland, and can provide reference for the management and protection of the Qinghai-Tibet Plateau ecosystem.