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Simulation Of Climate Change Impact On Grassland Ecosystem In Inner Mongolia

Posted on:2008-01-27Degree:MasterType:Thesis
Country:ChinaCandidate:W P ShengFull Text:PDF
GTID:2120360215978086Subject:Science of meteorology
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Inner Mongolia, most land of which is covered with natural grassland, is in the middle of Eurasia. It becomes the sensitive zone of global climate change because of the rigorous physical geography, fiercely fluctuant climate, and the complicated socioeconomic conditions. To analyze the change of main climate factors, grassland distribution, grassland net primary production(NPP), as well as the soil organic carbon (SOC) in Inner Mongolia is important to the reasonable utilization of grassland and the economic development in the minority nationality area under future climate conditions. Firstly, the changes of annual mean temperature, precipitation and other climate factors in Inner Mongolia were analyzed based on the data from 2011 to 2100 which is the output of PRECIS. Secondly, the kinds of grassland were plotted depending on the Ivanov humidity index and the spatial change of each kind of grassland was analyzed. Finally, the NPP and SOC were calculated by the CENTURY model, and then the changing trend and the relationship between them and climate factors for every kind of grassland were analyzed. The conclusions are as following:I. The annual mean temperature would increase by 0.7℃, 0.2℃; 3.4℃, 1.2℃; 6.3℃, 1.9℃in 2020s, 2050s and 2080s under A2 and B2 scenarios, with the same distribution pattern of baseline, while the annual precipitation would decrease by 121.9 mm, 132.9 mm; 90.9 mm, 118.5 mm; 50.4 mm, 104.7 mm, with increase in low value areas but decrease in high value ones. The west part of Inner Mongolia would be warmer and wetter, while the north-east part would be warmer and drier by the collaboration of temperature and precipitation under the climate change.II. The areas of typical steppe and desert steppe would increase, but the area of meadow steppe would decrease under the future climate change scenario. The temperate grassland would broaden west to the desert area and north-east to the forest area, and it is more evident that the meadow steppe moves north in A2 scenario, but the desert steppe moves west under B2 scenario.III. Compared with the baseline years, the NPP would increase in all kinds of grassland under the both scenarios. The increase of meadow steppe is the most, while the typical steppe is the least, and the increase under A2 scenarios is more than that under B2 scenario. The fertilization effert of CO2 is most obvious in desert steppe and most slender in meadow steppe. The linearity relationship between NPP and the annual precipitation is more notable than that between NPP and the mean temperature.IV. There are different SOC responses to climate change depending on different types of grassland. The SOC of meadow steppe would be increasing all through 2011 to 2100, while the SOC of desert steppe would increase first and then decrease, under the climate change scenario. And the typical steppe under A2 senario is the same with the desert steppe, but it has a same trend with the meadow steppe under B2 senario.The grassland ecosystem in Inner Mongolia is still a carbon sink under the climate change.
Keywords/Search Tags:Climate Change, Inner Mongolia, CENTURY Model, Net Primary Production (NPP), Soil Organic Carbon (SOC)
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