放牧压力下高寒草甸夏秋草场潜在生产力的研究

Analysis of the potential productivity of summer autumn Kobresia humilis meadow under grazing

采用最优控制理论研究矮嵩草草甸能量动态分室模型的潜在生产力，通过放牧强度随时间的最优变化，使作为目标函数的累积采食量最大。结果指出：夏秋的高寒草甸在常放牧压力下，采食地上生活部分的最优放牧强度为２５．９０ｋＪ／（ｍ２ｄ），其最大累积采食量为３．２６８ＭＪ／ｍ２。采食地上生物量的最优放牧强度为２５．９４ｋＪ／（ｍ２ｄ），其最大累积采食量为３．６３１ＭＪ／ｍ２。在变放牧压力下，最优放牧强度的最大累积采食量为８．７４９ＭＪ／ｍ２。是常放牧压力下的２．５倍。

It has been analysed by applying optimal control theory to the compartment modelling of energy dynamics in Kobresia humilis meadow, the productivity being regarded as the objective function to be maximize through optimization of the time course of stocking rate. Computing of modelling system provided an inference base to support a recommendation concerning the stocking rate and accumulated intake. The recommendation is as follows: under constant grazing, the optimal stocking rate is 25.90kJ/(m 2d) with the maximal accumulated intake 3.268MJ/m 2 the optimal stocking rate is 25.94 kJ/(m 2d) with the maximal accumulated intake 3.631MJ/m 2 . Under variable grazing, the maximal accumulated intake is 8.749MJ/m 2 as 2.5 times as constant grazing.