杭州湾滨海湿地芦苇生物量及N、P储量动态变化

以慈溪杭州湾滨海湿地GEF项目区内芦苇(Phragmites australis)为研究对象,采用定位监测和实验室分析相结合的方法,系统分析了其地上生物量、氮、磷含量和储量在生长季节的动态变化,旨在为GEF项目的实施提供科学依据.结果发现,随着时间的推移,各器官生物量逐渐增加,叶片和地上生物量在9月份达到最大,此后又稍有降低,茎则在10月份达到最大;生长初期(4~5月份)叶片生物量氮、磷含量较高,6~7月份随着生物量剧增而迅速下降,8~9月份由于叶片生长放缓,含量又逐渐增加,此后随着叶片衰老又逐渐下降,而茎氮、磷含量在整个生长季节均呈现逐渐下降的过程;各器官氮、磷储量与生物量间存在较好的相关性,其变化趋势与生物量基本相同;叶片氮、磷储量在8月份达到最大值[分别为(10.28±3.88),(0.53±0.21)g/m2];茎和地上储量最大值则出现在9月份[分别为(7.33±2.22),(0.57±0.04),(16.48±1.07),(1.01±0.10)g/m2].

Dynamics of biomass and N,P storage of Phragmites australis in Hangzhou Bay Wetlands

Seasonal dynamics of leaf and stem biomass, as well as N, P content and N, P storage were determined in Global Environment Fund (GEF) program site, Hangzhou Bay Wetlands. With the growth of Phragmites australis, leaf and aboveground biomass increased firstly and reached the maximum value in September, then decreased. While stem biomass increased during the whole growth season. It showed higher N, P concentrations at the early stage (April~May) because of small biomass, then decreased greatly with the expanding of leaf when going into fast growing period (June~July), and increased as the leaf growth became stable (August~September), finally, decreased again with the leaf becoming senescence. But N, P content of the stem decreased gradually in whole growth period. There was a good relationship between N, P storage and biomass, and highest storage was found for leaf in August with (10.28±3.88) and (0.53±0.21)g/m2, and for stem and aboveground biomass in September, the values were (7.33±2.22), (0.57±0.04) and (16.48±1.07), (1.01±0.10)g/m2, respectively.