Research On The Numeric Dynamics Of Abies Georgei Population Under Climate Change

Although the changes of current projections of future climate associated with increases in atmospheric greenhouse gases have a high degree of uncertainty, widely attention has still been drawn on the potential effects of climatic chages on the conservation of biodiversity. The quality of habitat will be greatly effected by the vegetation distribution range and the quantity of plant population of which closely related to the climate change. It indicates that the protection of wild animal will be threatened directly if the habitat changed. Based on the project of Natural Science Foundation of China which focused on the golden monkey habitat characteristics under the climate change pressure, the study about the effects of climate change on vegetation population of the golden monkey habitat was proposed.Because different times and different altitudes provide the information about the difference of temperature and precipitation, the effects of different climate condition on Abies georgei population quantity can be investigated by comparing the Abies georgei population quantity of the same plot of1992and2012. Therefore, in this work the survival rate, mortality, age structure and survival number of Abies georgei population was studied in detail compared to show that changes have happened at different altitudes and times. Furthermore, the reasons on population changes were analyzed under different climate conditions.Compared the Abies georgei population of the1992with2012, the structure of two period of Abies georgei population belongs to the growing population, which indicates the natural forest of Abies georgei population is in good condition. But the value of2012population age structure is higher than1992, it suggests that the growth of population was indeed effected by the temperature and precipitation. In addition, the trend of two period mortality curve are almost similar which have high mortality in age of class I and II. It shows the competition of live factors, such as space, illumination and nutrient, caused high mortality.The different performance of different elevation can reflect that the increase of temperature and precipitation are good for the update of Abies georgei population at different altitude gradient. However, the increase of the density is likely to make the population competition inside the sample area for better natural forest canopy density, especially the growth significantly lower elevations.(1)The young level of Abies georgei population which distributed in low altitude region (<3750m) have appears increasing number most significantly, and the original shape with different age class distribution converts to the typical inverted J type curve. This may be due to the rise of temperature and precipitation increasing, but the young level increases at low altitude may result in the increasing of tree species distribution density, the intensity of intraspecific and interspecific competition at low altitude in the future.(2) The altitude region (3750-4000m) is the stable region of Abies georgei, without obvious change have not taken place between two period..(3) The Abies georgei population, which was distributed a few of individuals in high altitude(>4000m),has long life. The quantity of young individuals was increased on2012. Because Abies georgei population was effected by climate condition at high altitude, and the relatively open woodland advantages to Abies georgei growth.In conclusion, the population quantity characteristics of three altitude have really changed under the climate change, it indicates that the method of the comparison of the study of multiphase set up half the population structure dynamic contrast with practical. There is no shrink condition of vegetation distribution in the lower limit, and no migration phenomenon was happened at high altitude. Probably because20years interval is too small for long-lived tree species. Based on our conclusion, it is important to be able to predict likely long-term structure of Abies georgei population response to climate change. In addition, it need add the mechanism model, mountain weather data, rings response to climate change and other methods to this future study, so it can improve research on the quality of the golden monkey habitat in the future.