甘肃马鹿冬季放牧践踏作用及其对土壤理化性质影响的评价  

Evaluation on trampling of grazed Gansu wapiti (Cervus elaphus kansuensis Po cock) and its effects on soil property in winter grazing land

作　　者：侯扶江[1] 任继周[2] 

机构地区：[1]兰州大学草地农业科技学院甘肃草原生态研究所 [2]中国农业科学院草原生态研究所,兰州730020

出　　处：《生态学报》2003年第3期486-495,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金重点资助项目 ( 39630 2 5 0 );国家自然科学基金重大研究计划资助项目 ( 90 1 0 2 0 1 1 )资助~~

摘　　要：确定了草地上路径的密度、宽度、深度和土壤容重等 5项放牧家畜践踏作用的观测指标 ,用该 5个指标构建了 2个践踏综合指数 ,定量了甘肃马鹿冬季放牧的相对践踏强度 ,其可信度和可行性较高。定义了放牧践踏强度 ,根据冬季牧场载畜量和践踏综合指数确定了甘肃马鹿的绝对践踏强度和放牧强度。草地生长季土壤水分随践踏增强而减少 ,对放牧践踏的敏感性随着生长季推移逐渐降低。 0～ 40 cm土层全氮和速效氮含量 ,以及 0～ 2 0 cm土层速效磷、全盐和有机质含量 ,随践踏强度增加而减少 ,0～ 2 0 cm土层全磷呈逐渐增多趋势。 0～ 40 cm土层水分和速效氮含量对践踏的敏感性随土层加深而上升 ,0～ 30 cm土层全氮含量对家畜践踏的敏感性高于 0～ 1 0 cm土层 ,0～ 1 0 cm土层速效磷含量对践踏的敏感性高于 1 0～ 2 0 cm土层。土壤子系统对放牧践踏作用的耐受性表现为土壤理化性状之间相互关系的稳定性。冬季牧场践踏强度梯度上 ,土壤质量综合指数的的变化存在拐点 ,对应着草地从稍形过牧到明显过牧和短花针茅在群落中的次优势种地位。Animal trampling plays more important role than defoliation and excrement in gra ssland, but there were few studies on trampling and no quantitative index of tra mpling intensity available. Five characteristics of the path trampled by grazed Gansu wapiti in winter grazing land were quantitatively identified as the measur ing indices of trampling intensity. Density, width and depth of path and soil bu lk density in path decreased, and number of plant in path increased as grazing p ressure reduced. Soil bulk density and density of path was more susceptible than width of path to grazing. On the base of the above 5 indices, two comprehensive indices of trampling intensity i.e. Comprehensive Trampling Index 1 and Compreh ensive Trampling Index 2 were established and they were used to quantify trampli ng intensity of grazing. Trampling intensity of grazing was defined as the accum ulated weight of grazed animal which live body weight was multiplied by their gr azing time in the definite area of grassland. The absolute trampling intensity a nd grazing intensity in different sites of winter grazing land were quantified o n the basis of both livestock carrying capacity and Comprehensive Trampling Inde x. The soil water content at early stage in winter grazing land was more susceptibl e to trampling than at middle stage of herbage growing season and was the least susceptible in late stage. Total nitrogen and available nitrogen in 0～40 cm soi l profile reduced with the increased trampling intensity in winter grazing land as well as the contents of available phosphorus, total salt and organic matter i n 0～20 cm soil profile while total phosphorus in 0～20cm soil profile increased . The susceptibility of soil water and available nitrogen to trampling increased with the depth of soil layers in 0～40cm soil profile. Total nitrogen in 0～30c m soil layers was more susceptible to trampling than that in 0～10cm soil layer. And there was higher susceptibility of available phosphorus to trampling in 0～ 10cm soil la

关 键 词：甘肃马鹿 放牧 践踏强度 践踏综合指数 耐受阈值 理化性质 土壤 

分 类 号：S812[农业科学—草业科学]