Analysis On Soil Respiration Of Vegetation Community And Its Effect Factors In Sand Land

As a very important link in carbon cycle of terrestrial ecosystem, and soil respiration is becoming a hot issue currently. The object of research is that to reaserch the soil respiration of Sand plant Community in the Sand Land which located in Semi-arid region. A serice factors, included soil respiration rate, soil temperature,soil moisture, Soil mineral elements, soil microbial carbon and nitrogen, as well as aboveground and underground biomass at different times and different locations, are measured to analysis soil respiration variation characteristics in various types of sand. In order to provide scientific basis for carbon study on Semi-arid region, correlation factor for selection and scheduling key factors of soil respiration are investigated. And the main results are as follows:First of all,soil respirations in different seasons have different characteristics of diurnal variation curve in the Sand Land. Double peak curves of soil respirations are appeared in May and July, while single peak in presented in October. With the enhancement of growth aboveground and underground biomass, the speed of soil respiration is increasing. From shifting sand land to fixed sand land. Soil respiration is influenced by the incrasing soil compaction, soil total phosophorus and other factors.The totally trend of daily average value of soil respiration is shown that the value of season discrepancy is higher than various kinds of sand land.For the second, environmental factors affect soil respiration process in the Sand Land. According to present studies, the orders of 53 environmental influenced factors are as follows:vegetation community structure and soil moisture>Soil mineral elements, soil microbial carbon and nitrogen> soot length density and Soil mineral elements>soil physical properties and soil microbial carbon.soil physical properties common factors are shown as:F物1>F物2>F物2.soil mineral elements content common factor are expressed as:F矿1>F矿2>F矿3.for soil microbial common factor, the order is:F微1>F微2>F微3.vegetation community structure common factors are pointed as:F植1>F植2.Finally, the tendency of soil respiration daily rate is consistented with its environmental factors, affected the soil respiration process in the Sand Land. The totally trend of all factors of soil respiration, included vegetation community structure, soil moisture, soil mineral elements content, soil microbial nitrogen, and root length density, etc,shown that the value of season discrepancy is higher than various kind sand land. However, it can not be found in the weakest influence factors of soil physical properties and soil microbial carbon. According to the date of analyze, the vegetation biomass and coverage factors are the key factors of influence soil respiration process.