Study On Dynamic And Environment Impact Factor Of Ecosystem Phptosynthesis And Respiration Of Wuliangsuhai Lakeside Zone

Carbon cycle of Wetland ecosystem is an important branch of carbon cycle of terrestrial ecosystem, it has become a big hot spot to the research of global change and cycle of terrestrial ecosystem.The text studies diurnal dynamic and dynamics of the growing season of Net CO2 Exchange, Total respiration, Photosynthesis of Nitraria sibirca Pall.、Suaeda glauca Bunge、Scirpus triqueter L.、Phragmites australis (Cav.)Trin. community and environment factors with LI-7000 H2O/CO2 infrared analyzer external homemade gas chamber method in lakeside of Wuliangsuhai in September 2013. The study is helpful to further understanding the process of carbon cycle of the lakeside ecosystem, provides valuable reference to correctly estimate carbon library of the lakeside zone ecosystem. The results were as follows:1.In the growing season, ecosystem Net CO2 Exchange, Total respiration and Total photosynthetic showed obvious spatial heterogeneity in wetland ecosystem of lakeside of Wuliangsuhai.2.During the growing season, diurnal dynamic of Net CO2 Exchange rate of lakeside zone ecosystem showed unimodal curve, the difference of characteristics of diurnal dynamic of Net exchange of different communities was very obvious; generally, absorption peak of Ecosystem net exchange appeared before noon, maximum (lowest) of diurnal net absorption is about-5.37μmol*m-2*s-1; peak of Ecosystem net exchange rate appeared in July; radiation intensity was the main environmental factors to affect net exchange rate of lakeside, and temperature was different influences of different communities.3.During the growing season, diurnal dynamic of Ecosystem respiration rate of lakeside wetland showed unimodal curve; peak time of Respiration rate was at noon or later; peak of Respiration rate and peak of temperature was the basic synchronization; the growing season dynamic of Respiration rate of different communities and ecosystem was the basic synchronization, peak of Total respiration rate showed in July, and the lowest showed in September; temperature was the main environmental impact factors of Respiration rate of lakeside zone ecosystem.4.During the growing season, diurnal dynamic of Ecosystem total photosynthetic rate also showed the obvious features of the diurnal change; the growing season dynamic of different community and ecosystem was the basic synchronization, presented a single-peak curve, the maximum Total photosynthetic uptake value showed in July; Photosynthesis intensity of communities was obviously different, on the length scales of day and season, Photosynthetic intensity of Phragmites australis (Cav.)Trin. and Scirpus triqueter L. was much higher than Nitraria sibirca Pall. and Suaeda glauca Bunge. community.