珠江三角洲城市森林植被生态系统水质效应研究

Study on the Water Quality of Urban Forest Ecogystem in the Pearl River Delta

2002—2003年对顺德大良大岭山常绿针阔混交林集水区水循环过程进行了定位监测,该林区年降水量为1628 9mm,5—9月份的降雨量占82 4%,穿透降水占降雨的85 01%,干流占3 17%,冠层截留占11 82%,冠层水文效应显著。工业区年降雨pH均值为5 27、酸雨频率67 8%;大良和龙江居民区年降雨pH均值分别为5 84、5 72,酸雨频率平均为27 1%;森林区大气降水的pH值6 31、酸雨频-、SO42-的含量小于国家I类水标准,总P(TP)、Cu、Zn含率为6 5%。森林区降水中Pb、Cd、Cl-、NO3量接近国家I类水标准。大气湿沉降化学物质经过林冠后,穿透雨的总P、K、Zn、Pb浓度分别增加了3-、Cl-、NO3-、1、2、7、1倍,Al、Ca、Cu浓度减少了89 8%、40 7%、30 5%。土壤105cm深度渗透水PO42-阴离子的总浓度相对15cm深减少33 5%;Cu、Zn、Pb、Cd浓度相对15cm深的渗透水分别减少SO4了62 5%、64 5%、38 9%、84 6%;森林土壤的储虑机制对于输出环境的径流水质量有显著改善作用。

Based on stationary observation and chemical analysis in the subtropical evergreen broad-leaved forest ecosystem at Daling Mountain in Daliang town of Shunde from 2002 to 2003, the hydrochemical cycles in the ecosystem was studied combined with their hydrologic process. The distribution of rainfall was 1 628.9 mm. The amount of rainfall from May to Sep. represented as about 82.4% of total precipitation.The amount of throughfall took 85.01%,the amount of stemflow took 3.17%,and 11.82% of annual rainfall was intercepted by the forest canopy.The average of pH of rainfall was 5.27 and the frequency of acid rain was 67.8% in industrial estate of Daling town.The average of pH of rainfall was respectively 5.84 and 5.72 and the frequency of acid rain was 27.1% in residential area of Daliang town and Longjiang town. The average of pH of rainfall was 6.31 and the frequency of acid rain was 6.5% in forest.By analyzing the water quality and the throughfall,it showed that the content of most ions in throughfall increased, the concentrations of TPKZnPb in throughfall were higher than that of those in rainfall by 4 times1 times2 times7 times1 times respectively,and the concentrations of AlCaCu were less than that of those by 89.8%40.7%30.5% respectively.