草地改良对陆地生态系统养分的影响——以福建省建瓯市牛坑龙草地生态系统试验站为例  

The Effects of Grassland Improvement on Terrestrial Ecosystem's Nutrients:A Case Study of Jian'ou Niukenglong Grassland Ecosystem Experimental Station

作　　者：朱连奇[1] 许叔明[1] 陈沛云[1] 

机构地区：[1]河南大学环境与规划学院,开封475001

出　　处：《地理学报》2003年第5期703-711,共9页Acta Geographica Sinica

基　　金：河南省自然科学基金课题(0311051700);河南省高校青年骨干教师项目~~

摘　　要：以福建省建瓯市牛坑龙草地生态系统试验站为例,研究了土地覆被类型从荒坡地到人工草地的转变所引起的陆地生态系统养分含量和营养元素循环系数的变化。结果表明,随着土地覆被类型由荒坡地到人工草地的转变,陆地生态系统土壤中N、P、K的含量增加,而Al的含量逐渐降低;植被中的养分也经历了从无到有的历程,整个陆地生态系统养分贮存量的变化中N、P、K总量增加,而Al的总量减少。在陆地生态系统的两个群落中,所有元素的循环系数都发生了相应变化,这种变化是陆地生态系统对土地覆被类型变化的一种响应。This paper studies the effects of grassland improvement on distributions and circulations of nutrients in terrestrial ecosystems, taking Jian'ou Niukenglong Grassland Ecosystem Experimental Station as a case. During two years experiment, the land cover types had been transformed from desert slope-land to grasslands. The experimental results indicate that with the increase in vegetation coverage, the soil total concentrations of nitrogen, phosphorus, and potassium grow rapidly, but that of aluminum decreases obviously. The increases in the total concentrations of nitrogen, phosphorus, and potassium are mainly the consequences of changes of the factors affecting soil evolution, e.g., soil moisture, and changes of soil evolution processes, e.g., weathering rate and decrease of soil erosion. The changes are caused by land coverage growth during the processes of land cover change from desert slope-land to grassland. Conversely, with the change of the land cover types, the increase of land coverage, the activity of aluminum accelerated as well, the down-penetration and lateral penetration of aluminum have been strengthened. Therefore, the loss of aluminum within the experimental terrestrial ecosystem was inevitable, and the total concentration and content of aluminum in the soil have become smaller and smaller, though the growth of grass has been absorbing some amounts of aluminum. Land cover change also affects the circulations of nutrients in terrestrial ecosystem, for the purpose of study on nutrient circulations, we choose plant's absorption, litter and reservation of nutrients to establish the index to indicate the situations of nutrient circulations within terrestrial ecosystems. The results made it clear that in the two land cover types, i.e., two grassland ecosystems, the sequence of nutrient circulation indices are N>K>P>Al in Chamaecrista rotundifolia (pers) green + Pasalum thunbergii and P>N>K>Al in Glycine max var. + Pasalum thunbergii. On the basis of the study, we can conclude that land cover change affec

关 键 词：士地覆被变化 陆地生态系统 营养元素含量 营养元素循环 

分 类 号：S812[农业科学—草业科学] X171.1[农业科学—畜牧学]