Research On Biomass And Carbon Storage Of Dominant Plant Communities In Poyang Lake Wetlands

This paper is started from the survey of dominant plant communities in Nanji wetland national nature reserve,where lies in the south of Poyang lake.6 kinds of donimant plant communities were selected to study:Cynodondactylon?Linn.?Pers,Triarrhena lutarioriparia L Liu,Carex cinerascens Kükenth.,Zizania latifolia?Griseb.?Stapf,Phragmites communis?Cav.?Trin.ex Steud,Phalaris arundinacea Linn.As our study,we collected plant communities samples monthly to analyze characteristics of different plant communities ofbiomass and carbon storage in species and components?leaves,stems,withered and roots?.Furthermore,systematically carried out dynamic changes of plant communities biomass,carbon storage and its allocation,the study is significant to further evaluate the carbon balance of Poyang lake wetland,and to provide basic data and scientific basis for the response of wetland plant community in Poyang lake to water level change.The main results as follows:?1?The aboveground biomass of dominant plant community in spring srowth?April?in Nanjishan Wetland were:Phalaris arundinacea Linn(1158.51g·m^-2)>Triarrhena lutarioriparia LLiu(971.8g·m^-2)>Phragmites communis?Cav.?Trin.ex Steud(557.65g·m^-2)>CarexcinerascensKükenth.(545.77g·m^-2)>Cynodondactylon?Lin n.?Pers(329.42g·m^-2)>Zizanialatifolia?Griseb.?Stapf(284.48g·m^-2),among which the aboveground biomass of Phalaris arundinacea Linn community was the largest,and the aboveground biomass of Zizania latifolia?Griseb.?Stapf community was the smallest.?2?The aboveground biomass of dominant plant community in Nanjishan Wetland was changed in seasons,the aboveground biomass continuously decreased from autumn to winter.On the contrary,plant biomass was on the rise through the spring.In terms of biomass distribution of various components in the plant community,the stems?leaves?>withered in the autumn and winter seasons,and the opposite in spring;there was a significant positive correlation between plant community stem and leaf biomass mass fraction,and the stem?leaf?was negatively correlated with the biomass quality score of withered biomass.?3?The underground root biomass of dominant plant community in spring srowth?April?intheNanjiwetlandwereCarexcinerascensKükenth.(1296.44g·m^-2)>Triarrhena lutarioriparia L Liu(555.25g·m^-2)>Cynodondactylon?Linn.?Pers(537.36g·m^-2)>Phalaris arundinacea Linn(341.6g·m^-2)>Zizanialatifolia?Griseb.?Stapf(338.67g·m^-2)>Phragmites communis?Cav.?Trin.ex Steud(284.48g·m^-2).Among them,the underground biomass of Carex cinerascens Kükenth.community was the largest,accounting for 71.4%of the total biomass of Carex cinerascens Kükenth.community.In general,the underground biomass of plant community was positively correlated with the total biomass of the community,and the seasonal variation trend of underground biomass was opposite to that of aboveground biomass.?4?There was a negative correlation between the biomass and the underground biomass of dominant plant community in the Nanjishan wetland.In terms of root-shoot ratio,6 kinds of plant community rootshoot ratio in April were:Carex cinerascens Kükenth.community?2.38?>Cynodondactylon?Linn.?Pers community?1.63?>Zizania latifolia?Griseb.?Stapf community?1.03?>Triarrhenalutarioriparia L Liu?0.65?>Phragmites communis?Cav.?Trin.ex Steud?0.51?>Phalaris arundinacea Linn community?0.96?,Each community root-shoot ratio was changed obviously,it was the biggest in the fall and winter,while the smallest in the spring.?5?The total carbon content of 6 kinds of plant community in spring srowth?April?intheNanjishanwetlandwere:CarexcinerascensKükenth.community(581.37gC·m^-2)>Phalaris arundinacea Linn community(168.59gC·m^-2)>Cynodondactylon?Linn.?Pers community(333.66gC·m^-2)>Triarrhena lutarioriparia L Liu community(417.54gC·m^-2)>Phragmites communis?Cav.?Trin.ex Steud community(300.89gC·m^-2)>Zizania latifolia?Griseb.?Stapf community(229.29gC·m^-2).The result shows:significant seasonal differences are found in the allocation of the plant organs,most of plant community carbon content are concentrated in the underground root part in the fall and winter,,especially the proportion of root carbon content in Cynodondactylon?Linn.?Pers community and Carex cinerascens Kükenth.community were the largest,respectively accounted for60%,79%.