湖南省冷水江市大嵊山大气污染与马尾松衰亡

DECLINING OF PINUS MASSONIANA IN RELATION TO AIR POLLUTIONIN DASHENGSHAN, LENGSHUIJIANG, HUNAN

作者对湖南省冷水江市大嵊山大气污染与马尾松衰亡进行了研究，研究结果表明大气综合污染指数在３个研究点上分别为１．００（对照）、１．７６和２．２３。而以林分密度、林分非衰亡率、针叶长度、针叶干重、马尾松平均高、平均胸径等因子计算出的林分外貌综合得分从１７３．９下降到１４３．５和１３２．５。在一年四季，马尾松针叶中叶绿素含量也是清洁区显著高于污染区，而叶绿素ａ／ｂ值则是污染区的高，峰值较正常的提前。马尾松在受到大气污染作用后，针叶中营养元素含量呈下降趋势，尤其是氮。根据树于解析发现大气污染对马尾松高生长和胸径生长都具有抑制作用，但并不表现出同步效应，对高生长的抑制有一个滞后现象，时间在２～３年。另外，大气污染对马尾松的结果影响很大，污染区的马尾松单株拥有球果数仅为清洁的２５％，用灰色系统理沦对马尾松材积与相关影响因子进行关联度分析发现，材积与综合污染指数的倒数有很好的关联件，关联度达到了０．７７３。

The coniferous forest in the subtropical zone of China is suffering from very severe decline. The paper studied the declining pattern of polluted P. massonlana stand in terms of stand characters, tree growth, physiological properties and contents of nutrients such as nitrogen, phosphorus and potassium of the needles. The results indicated that the number of chlorotlc individuals increased with air pollution. The weight of needles and the number of corns per tree in the polluted site respectively, the contents of chlorophyll and nutrltlve elements of the needles in the polluted slies were lower than In the nonpolluted site.In addition, the growth values of the height, diameter and volume of the pine in the polluted slies were lower than those of pine In the nonpolluted site.