青海湖地区紫花针茅型中度与重度退化草地光能转化效率的研究

Study on the Conversion Efficiency for Solar Radiation Energy of Heavy and Moderate Degraded Grassland of Stipa Purpurea in Qinghai Lake Area

通过青海湖地区紫花针茅型中度与重度退化草地群落光能转化效率的研究,结果表明,中度与重度退化样地地上部分固定能量的季节动态基本相同,都呈“单峰”曲线,在8月下旬地上部分固定的能量达到最大值,其值分别为194188KJ/m2、872.61KJ/m2。两退化样地植物群落地上部分现存量的热值大于凋落物的热值,以植物生长旺盛期热值含量最高,枯黄期次之,返青期最低。地上部分植物量与能量固定之间呈极显著的线性正相关,地上植物量每增加1g/m2,中度与重度退化样地植物群落贮存的能量将随之分别增加18.687KJ/m2、18.055KJ/m2,在地上0￣10cm区间中度与重度退化样地固定的能量分别占地上总能量的79.25%、81.15%。中度与重度退化样地地上部分对总辐射转化率的变幅分别为-0.076￣0.13、-0.022￣0.045,对太阳总辐射的转化率分别为0.03%、0.013%。

According to the study on the conversion efficiency for solar radiation energy of heavy and moderate degraded grassland of stipa purpurea in Qinghai lake area, the results showed that seasonal dynamic of energy storage of heavy and moderate degraded plot was similar and took on single apex, the maximum value of energy storage appeared in the last ten days of August and was 194 188KJ/m^2, 872.61KJ/m^2 respectively. The caloric value of standing crop aboveground was more than that of litter fall, the caloric value was the highest on the flourishing stage of forage, the lowest during the green up period, the second on the withering stage. The phytomass aboveground had significant positive correlation of linearity with energy storage.when phytomass aboveground increased by lg/m^2, energy storage of plant community of heavy and moderate degraded plot increased by 18.055KJ/m^2, 18.687KJ/m^2 respectively. Between zero and ten eentimetres aboveground the energy storage of heavy and moderate degraded plot was 81.15%, 79.25% of total energy aboveground respectively, the amplitude of the conversion efficiency of heavy and moderate degraded plot was -0.076-0.13, -0.022-0.045 respectively, and the eoversion efficiency for solar radiation was 0.013%, 0.03% respectively.