城镇生活污水排放对红树林植物群落凋落物的影响

EFFECT OF WASTEWATER DISCHARGE ON LITTER PRODUCTION OF A MANGROVE SWAMP

利用凋落物收集网研究城镇生活污水排放对红树林植物群落凋落物的影响 .所研究的红树林群落年总凋落物量为 1198.91gm-2 ,其中叶片和繁殖物部分共占 90 %左右 .总凋落物量具有明显的季节变化模型 ,凋落物的高峰期落在多雨的夏季 ,尤其是 8月份 .污水排放一年期间 ,排污样带和对照样带之间红树林的总凋落物量以及凋落叶中的总有机碳、总氮、总磷水平没有显著的差异 ,污水排放没有导致红树林植物群落的凋落物量发生明显的变化 .月凋落物量 (Y/gm-2 )与月降水量 (X1/mm)、月平均气温 (X2 /℃ )的回归公式分别为Y =0 .174X1+ 6 4.2 15 ,r=0 .6 3 和Y =7.0 5 3X2 - 5 8.435 ,r=0 .6 1 ,相关极显著 .图 4表 3参 2

Litter production in a mangrove swamp was estimated by litter trapping in 2 sites, one receiving wastewater (Site A) and the other used as control (Site B). Annual litter productfion was about 1 198 g m -2 , with leaf and reproductive materials accounting for 90% of total litter production. A distinct seasonal pattern was found with peak litter fall occurring in summer rainy season, particularly, in August. No significant difference in litter production and concentrations of organic carbon, N, P in litter leaves was found between sites A and B. These preliminary results indicated that one year sewage discharge did not produce any apparent impact on litter falling of mangrove community. Monthly litter falling ( Y /g m -2 ) was positively correlated with monthly precipitation ( X 1/mm) and with monthly mean air temperature ( X 2/℃), ). The regression equations were Y = 0.174 X 1+64.215, r =0.63 ** and Y =7.053 X 2-58.435, r = 0.61 ** , respectively, showing a greatly significant relation. Fig 4, Tab 3, Ref 20