基于CASA模型的人工植被生物量的估算及特征分析

利用改进的CASA模型,结合Landsat TM遥感影像及气象数据,估算榆林飞播林2010年7月的植被净初级生产力。通过实测植被生物量,验证CASA模型在研究区的估算结果。结果表明:CASA模型适用于榆林飞播林植被净初级生产力估算;CASA模型估算的不同地区NPP区别明显,榆林市横山县与榆阳区交界处的植被NPP值最高,其值介233.21～414.15gC/m2之间;榆林飞播林生态系统属于较低生产力的生态系统;沙柳的NPP水平最高,以柠条+沙柳+沙蒿为播种模式的人工林地生物量最高;除沙柳、花棒和沙蒿外,其他飞播植物生物量与含水量无明显的相关性;不同飞播年代的同种植被生物量与含水量、土壤养分以及气候等因素之间具有密切的相关性。

Estimation and Characteristics Analysis of Artificial Vegetation Biomass Based on CASA Models

Using the improved CASA(Carnegie-Ames-Stanford Approach)model,combining with Landsat TM remote sensing image and meteorological data,the net primary productivity(NPP)of Yulin aerial seeding forest was estimated in July 2010.By use of the measured vegetation biomass,the estimation results of CASA model could be verified.The results indicated that CASA model can be applied to estimation of the NPP in the Yulin aerial seeding forest.The differences of the NPP among different areas which are estimated by CASA model were marked,the highest NPP found at the junction of Henshan and Yuyang,the value is between 233.21 and 414.15gCm-2;Ecological system of Yulin aerial seeding forest belongs to low productivity ecological system.The level of Salix psammophila NPP is the highest,In the artificial forest land,the planting pattern of biomass of Korshinsk Peashrub,Salix psammophila and Dester Wormwood is the largest.In addition to Salix psammophila,Hedysarum scoparium and Dester Wormwood,there is no significant correlation between plant biomass and water content.There exists close correlation between biomass and the factors which include water content,soil nutrient and climate of the same vegetation in different aerial years.