Comparison Study On Four Climate-Vegetation Relationship Models

Based on technology of Digital Earth,and 958 materological stations' data from 1950s to 1980s (including longitude,latitude,elevation,mean monthly and annual temperatures,mean monthly and annual precipitation,sun radiation,radiation rate,and wind speed,etc.),the effectiveness and accordance of four climate-vegetation relationship models (Penman model,Thornthwaite model,Holdridge Life Zone System,and Kira method) on China is compared. The results indecate that:(1) Penman model has KAPPA index value over 50 percent on both Temperate Steppe and tibetan plateau. It works well in tibetan plateau and is valuable in this area. (2) Thornthwaite model reaches 39.2 percent in tropical rain forests and seasonal rain forests. This would compensate the ineffectiveness of Holdridge Life Zone System in this area. (3) Holdridge Life Zone System is best one in whole terrestrial of China based on first level of vegetation division of China. But it may fail in tropical area,like west seasonal rain forests and rainforests (52) by the second level of vegetation division of China,west steppe (63),tibetan plateau temperate desert (86) and tibetan temperate steppe (84). (4) Kira method works comparably well to Holdridge Life Zone System in subtropical evergreen forest area. In low elevation and humid/semi-humid area,it works moderately well,but would far from the ground earth when applied in temperate desert and tibetan platou.Those four classification models work well in first class of Chinese Vegetaion Division. The KAPPA value of Holdridge Life Zone System,at high value of 0.57,would probably more effective than the others. But in specific area,like tibetan plateau,all of those models need to be refined or consider more elements and factors. This research also points out that the concept and technology of Digitall Earth would promote and push forward the climate-vegetation relationship research,especially in climate-vegetation factors,climatically parameters and modeling parameters,real time dynamic monitoring,effectively managing the magnitude data of climate-vegetation relationship information and supporting the mainframe of Functional Types Modeling Library.