河西走廊井泉灌区农户生态系统能流、物流特征及其效应的研究

运用生态学的系统分析方法,以河西走廊井泉灌区养殖业集约化程度较高的农户生态系统为对象,对系统的能量流动和物质循环特征以及初次级生产的生态效率进行分析,并对畜牧业在系统中的地位和作用进行客观评价。结果表明,系统开放程度高,投入、产出高;结构不合理,潜伏着一定的不稳定性和生态脆弱性。系统可食畜产品和可食农产品的商品率分别为93.93％和30.76％。初级生产光能利用率为0.49％,辅助能、氮和磷的产投比分別为3.11,0.79和0.49。次级生产饲料能、氮和磷的转化率分别为11.02％,19.19％和15.62％,由初级产品干物质转化为动物蛋白质的效率为2.58％。畜牧业已成为系统中不可缺少的组成部分。

Features and Effects of Energy Flow and Nutrient Cycle in a Farm Ecosystem in well and Spring Water Irrigated Area in Hexi Corridor

The feature of energy flow, nutrient cycle and the ecological efficiency of primary and secondary production in the farm ecosystem, in which animal husbandry was higher intensive, in the area irrigated with water from well and spring in Hexi Corridor was analysed with the method of systematic analysis.The role and position of animal husbandry in the ecosystem were evaluated objectively. The result showed that the degree of opening,input and output in the system were higher; the structure of the system was not very rational, and there were latent unstability and ecological failling The commodity ratio of the available animal product and crop product was 93.93％ and 30.76％,respectively;the efficiency of conversion from solar energy to primary product energy was 0.49％; the ratio of output to input of subsidy energy,nitrogen and phosphorus of the crop system was 3.11, 0.79 and 0.49, respectively; the efficiency of conversion of seed energy, nitrogen and phosphorus of the livestock subsystem was 11.02％,19.19％ and 15.62％,respectively, and the efficiency of conversion from dry matter of primary product to animal protein was 2.58％. It is concluded that the animal husbandry is the important and indispensable component in the farm ecosystem.