广西珍珠湾桐花树群落凋落物碳输出动态研究

Carbon Output Through Litter Fall in the Aegiceras corniculatum Mangrove Community in Zhenzhu Bay of Guangxi,China

于2013年开展广西珍珠湾桐花树群落的凋落物及碳输出动态研究.结果表明:桐花树群落年凋落重量为371.124g/m2.4个季度大小顺序为:秋季(160.457g/m2)>冬季(101.722g/m2)>夏季(74.658g/m2)>春季(34.287g/m2).各组分比例分别为:叶50.9%、果实20.7%、枝19.8%及花8.6%.叶凋落量在2月和10月各有1个峰值;枝凋落量集中于11月,受偶然事件影响;花、果凋落量分别集中在4月至6月、8月至9月,均为每月数量最高的组分.桐花树群落年凋落物碳输出量为165.655g/m2,各组分及月总碳输出的规律与凋落物重量一致.相关分析表明:凋落物不同组分与生态因子相关关系差异较大,花凋落物重量及其碳输出量与月均气温、水温显著相关,与风力、盐度无显著相关;叶、枝及月总凋落物重量及其碳输出量与4级以上风力显著相关,而与月均气温、水温、盐度无显著相关.

Abstract ： A study on the dynamics of litter fall and carbon output in Aegiceras corniculatum mangrove community was carried out in Zhenzhu Bay of Guangxi through the whole year of 2013.The results showed that the annual total litter fall weight was 371.124 g/m^2 ,which was very low in this study site and the world as well. And the seasonal litter fall weight followed the decreasing order of autumn （160.457 g/m^2 ）〉winter （101.722 g/m^2 ）〉summer（74.658 g/m^2 ）〉spring （34.287 g/m^2 ）.The annual total litter fall weight located 50.9% in leaf,20.7% in fruit,19.8% in twig and 8.60//oo in flower respectively.Two peak values of leaf litter fall weight occurred in February and October respectively,while the highest twig litter fall weight bloomed on November,the highest flower litter fall weight on April until June,and the highest fruit litter fall weight on August and September.The annual total carbon output through litter fall reached 165.655 g/m^2.The carbon output of each components and monthly total followed the same order as that of litter fall weight.The correlation analysis showed that the sum of flower litter fall weightand its carbon output correlated significantly with monthly mean air temperature and water temperature,while not with wind degree and salinity; and the leaf, twig and monthly total litter fall weight, and theirs carbon outputs correlated significantly with the percentage of 4-and- above wind degree in one month, while not with the monthly mean air temperature, water temperature and salinity.