The Carbon And Water Flux And Carbon Storages Of Snail Control And Schistosomiasis Prevention Forest Ecosysteme In The Middle And Lower Reaches Of Yangtz River

The carbon sink of Snail Control and Schistosomiasis Prevention Forest in the middle and lower reaches of Yangtz River had not been researched. The dissertation analyzed the change law of the carbon and water flux and the relationship of flux and environmental factors and carbon sink and source in different time and space scales in two types of Snail Control and Schistosomiasis Prevention Forest of different structure by the eddy-covariance system. The main contents and conclusions were as follows:1. The carbon flux was well-regularited change everyday in the two forests of Anhui and Hunan Province.In daytime, the ecosystem began to absorb CO₂ at about 7:30 am, and reached to the Max. about 12:00 at noon, then went down slowly, at about 18:00, the ecosystem began to release CO₂. The value of carbon sink or source varied owing to different season and forest ecosystem. In whole year, from end of March and early of April, the Popular began to unfold leaves, and the forest ecosystem started to absorb CO₂, namely carbon sink. Then at end of October and early of November, the photosynthesis of leaves stopped by defoliation, at the same time, the forest ecosystem became a carbon source nearly.2. The relationships of carbon flux of forest ecosystem and environmental factors were as follows:1) PAR The relationship of carbon flux and PAR accorded with the model of Michaelis-Menten, namely hyperbolic relationship which carbon sink increased with the accretion of PAR. In Anhui station, when the PAR was upwards 1200 μ mol/m².s, the dots dispersed and net CO₂ exchange was among -1.0^-1.5 mg/m².s. In Hunan station, when the PAR reached about 1600μ mol/m².s, the curve came to the Max. of carbon flux, about -1.2^-1.3mg/m².s.2) Temperature In Anhui station, monthly average carbon flux of nighttime and air temperature had linear correlation, namely when the air temperature arose, the carbon flux of nighttime augmented. The nighttime flux would increase with soil temperature in 5cm deep by exponential correlation. In Hunan station, the model of the monthly average carbon flux and air temperature was the relationship of logarithmic correlation, i.e. when the plant came to growing season with the air temperature uprising, the forest ecosystem turnaround from carbon source to carbon sink. And the...