Effects Of Climate Change On Distribution Of Larix Gmelinii In Northeast China

Based on the geographic distribution information of Larix gmelinii from forest form map obtained by field survey in1980s,1990s and the beginning of the21st century, with the12main climatic factors fitted by climate data modeled with RegCM3, using the model MAXENT-V3.3.3k developed by MAXENT principle as well as ArcGIS spatial analysis technique, the evolvement trend in suitability and geographic distributions of Larix gmelinii under climatic change scenario of AIB in21st century were predicted and analyzed.After the unsuitable area was filtrated by the data of land use in2000which is from<The land use Data of1km×1km grids in China (1980s,1995,2000)> obtained from Data Center for Resources and Environmental Sciences Chinese Academy of Sciences, according to the statistical principles and the description of probability from the Fourth Assessment Report of the International Panel on Climate Change(IPCC), the suitability class of distribution of Larix gmelinii was given by the existence probability (P):P<0.05(unsuitability),0.05≤P<0.33(low suitability),0.33≤P<0.66(middle suitability), and0.66≤P≤1(high suitability).The value of the area under the ROC curve (AUC) reached0.926, which indicated predictive accuracy of model achieved the "Excellent" level and the model can be used to research the relationship between climate change and potential distribution of Larix gmelinii in future. The prediction results show that the MAXENT model is able to point out the climatic key factors affecting distribution of Larix gmelinii including average maximum temperature in spring, annual mean temperature, precipitation in spring, precipitation in May, and their accumulated percent contribution is over to96%. Filtrated prediction results show that the suitable area of distribution of Larix gmelinii in2000includes forest areas of Daxing’anling and Xiaoxing’ anling, Hulunbuir League and Xing’an League of Inner Mongolia and the northeast of Changbai Mountain. Once air temperature arises continually and precipitation increases slowly, its distribution areas shift towards north and east The overall movement from the beginning of this century to the end of this century is about3.37°to north and0.47°to east. The original suitable areas are reduced substantially in size to separate from the overseas distribution areas and become a secluded forest zone around the center of suitable areas in region of Daxing’anling. At the end of the century, the suitable area in region of Xiaoxing’ anling and Changbai mountain will be vanished and the total areas will reduce approximately71.2%compared to the area which is under current climate conditions.