DECLINING OF PINUS MASSONIANA IN RELATION TO AIR POLLUTIONIN DASHENGSHAN, LENGSHUIJIANG, HUNAN
湖南省冷水江市大嵊山大气污染与马尾松衰亡

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.