Effects Of Simulative Of Climate Change On The Features Of Fargesia Rufa In Different Nitrogen Levels

Such human activity as the combustion of fossil fuel,deforestation and land use have not only exacerbated global warming,but also increased atmospheric nitrogen deposition.The IPCC report showed that the concentration of CO2in the atmospheric will rise to700μmol·mol-1and the average global temperature will rise by1.8to4.0℃by the end of this century.The emissions of nitrogen compounds will rise by1.34to1.62times by the year of2020contrasted with that of2000.At present,the reports on the physiological response of plants to environment and climate change concentrated on single factor and the interaction between them is rarely studied.Besides,the simulation of climate change and nitrogen deposition on alpine ecosystem vegetation and physiological characteristics of still have rarely been reported. Subalpine vegetation ecosystem is located in the mountains and canyons in the eastern Tibetan Plateau, and the plants there response to the global climate more sensitively.ln view of this, a closed growth chamber system was adopted in this experiment.The response of Fargesia rufa Yi to the elevation of CO2concentration (about700μmol·mol-1,EC),temperature(+2℃, ET) and their interaction were studied with the concentration of nitrogen of6.5mmolL-1N and without nitrogen.The main results are as follows:1) The SLA of leaves from Fargesia rufa increased by5.62%under the condition of ET processing without nitrogen and decreased4.05%and3.94%respectively under the condition of EC and ECT processing;the difference is not significant but the SLA of leaves decreased significantly under the condition of ET,EC and ECT processing with nitrogen.2) The content of water in the leaves from Fargesia rufa decreased by4.10%,2.25%and4.02%respectively under the condition of EC,ET and ECT processing without nitrogen. The content of water decreased obviously by3.00%,3.12%and3.88%respectively under the condition of EC,ET and ECT processing with nitrogen.At the same time,the water content decreased with varying degree with nitrogen and the water content decreased obviously under the condition of CON and ET processing and there is slight decrease under the condition of EC and ECT processing.3) Regardless of nitrogen application whether or not,The total carbon in the leaves from Fargesia rufa all increased under the condition of EC,ET,and ECT processing.The total carbon in the leaves from Fargesia rufa increased slightly under the condition of ET processing with nitrogen but decreased under the condition of ET and ECT processing.At the same time,the nitrogen concentration increased obviously by10.91%、7.09%and17.02%,but the phosphorous concentration in the leaves changed slightly.4) The soluble protein content increased apparently under the condition of ET processing especially when the system is with nitrogen and the content is33.18(±0.56)mg·g-1.The content of soluble protein decreased notablely under the condition of EC and ECT processing and increased apparently under the condition of EC,ET and ECT processing with nitrogen.5) The soluble sugar,starch,fructose,sucrose and cellulose content in the leaves increased apparently under the condition of EC,ET and ECT processing without nitrogen and among those starch content increased most and the content of tannin and lignin changed little. The soluble sugar,starch,fructose,sucrose,cellulose,tannin and lignin content in the leaves increased with different degree under the condition of EC,ET and ECT processing with nitrogen. The content of sucrose and cellulose increased apparently and the soluble sugar changed little with nitrogen,but the content of starch decreased apparently and the content of tannin and lignin decreased slightly.The range for Fargesia rufa growing in the system with elevated CO2,temperature and nitrogen to adapt the environment espanded,and at the same time, a variety of carbohydrate content increased apparently,but the water content decreased. The response of the SLA,carbon,nitrogen, phosphorous and soluble sugar in the leaves to different treatment is various.The response mechanism for Fargesia rufa to elevated CO2,temperature and nitrogen also is diffenent and more complex when they effect together.