The Research Of Carbon Cycle In The East District Of Zhengzhou Ecosystem

Climate warming is one key issue of global change and plays an important role on carbon cycling in terrestrial ecosystem.According to the forcast of IPCC, the associated impact of the CO2 concentration and greenhouse gas will cause the increase of global average temperature which will be 0.2℃every ten years.C limate warming will bring a series of environmental problems,such as rise of sea level ,the space-time distributing of precipitation and so on ,which will gradually influence the global environment.As the carbon source and sink,the terrestrial ecosystem has close and complicated relation with global climate warming.This is the resarchful stress of global changes.This experiment was conducted in the east area of Zhengzhou city, typical terrestrial ecosystem in this as the subject investigated.CO2 source/sink relation of terrestrial ecosystem in this region is studied systematically based on field-study data in the field ,and carbon reserves in whole region was estimated.At last ,the carbon circle model is established.The conclusions are as follows:1.Carbon souce/sink relation(1)Field ecosystemThere are certain differences among the fixation quantity of CO2 of different types of field ecosystems.All field ecosystem are carbon source,i.e net discharge of CO2 during the 11 hours at night.In the daytime,all the field ecosystem is carbon sink.The research shows: the corn ecosystem act as carbon sink from 9 to 20 clock ,and as carbon source since 21clock.The corn ecosystem has the bigger capability of CO2 net fixation with the fixation quantity of 36.45g/m2 per day.The soil respiration of paddy ecosystem is puniness ,the average quantity of which is 107mg/(m2.h),CO2 net fixation is 22.75 g/m2 per day.(2)Forestland ecosystemPoplar ecosystem server as carbon source,i.e net discharge of CO2 during the 11 hours at night.In the daytime ,along with the change of temperature and the light intensity ,poplar ecosystem change from carbon source to carbon sink .The CO2 net fixation of poplar ecosystem is 4.139 g/m2 per day. The willow ecosystem act as carbon source from 19 to 8 clock the next day .In the daytime ,except 13 clock,it is carbon sink all the time . The CO2 net fixation of willow ecosystem is 6.90g/m2 per day.2.Estimation of carbon pool(1)The research shows:the whole ecosystem of Zhengzhou east distraction fix 116 thousand tons of CO2 through photosynthesis,and discharge 57.2 thousand tons of CO2 to air through respiration ,which means that most of the plant-fixed carbon is released into air in the progress of respiration. The quantity of little fall is 21.9 thousand tons every years.The assimilated carbon mostly are set free into air through respiration and little fall ,the cumulation of carbon is only the little part.(2)The result shows: the carbon reserves of the ecosystem we studied is 947.3 thousand tons ,including 800.7 thousand tons in soil ,8.7 thousand tons in virescence plants,and 137.9 thousand tons in crop-forest ecosystem in suburb.The carbon reserves of soil account for 84.5% of the totall carbon quantity, which is the primary carbon pool .So,the change of carbon quantity of soil will cause the dynamic change of the whole distraction. The source of soil carbon pool is little fall ,therefore ,the quantity and discompisition of little fall will directly affect the carbon reserves of soil.