高寒矮嵩草草甸地上生物量和叶面积指数的季节动态模拟

Seasonal Dynamics Model of Aboveground Biomass and Leaf Area Index on Alpine Kobresia humilis Meadow in Qinghai-Tibet Plateau

基于2007年中国科学院海北高寒草甸生态系统定位站植被和气象观测资料,探讨了高寒矮嵩草草甸群落叶面积指数、地上生物量的季节动态变化及其数学模型,分析了叶面积指数与地上生物量的相互关系,以及气象条件对叶面积指数和地上生物量的影响。结果表明,高寒矮嵩草草甸群落植被生长期地上生物量的季节动态变化可以用Logistic回归模型拟合;植被叶面积指数的季节动态变化可以用三次函数曲线拟合,叶面积指数受温度和降水量的影响明显,与植物生长期日平均气温≥3℃的积温和降水累积量分别有三次函数的拟合关系,而考虑与积温和降水累积量的综合关系可用二元二次函数拟合;同时,叶面积指数与地上生物量之间有二次函数的拟合关系。

Based on the alpine Kobresia humilis meadow vegetation and weather data obtained at Haibei Alpine Meadow Ecosystem Research Station,CAS in 2007,we discussed the seasonal dynamic changes of the Leaf Area Index （LAI） and Aboveground Biomass （AB）,analyzed and simulated the correlation between LAI and AB,as well as the influence of climate on the process of LAI and AB. The results showed that during the plant growing season,the seasonal dynamic variation of AB could be fitted by the Logistic Regression model,and the seasonal dynamic variation of LAI could be fitted perfectly by cubic function LAI showed significant correlation with temperature and precipitation and they could be modeled by a binary quadratic function. The relationship of LAI and AB could be stated with a quadratic function.