赤红壤丘陵水土流失区马尾松纯林改造效益分析

ECO-BENEFITS FROM IMPROVING THE PURE PINUS MASSONIANA FOREST IN AN ERODED HILLY LATERIC RED SOIL AREA

马尾松纯林改造是当前植物生态和林业工作的一项迫切、重要的内容。经赤红壤丘陵水土流失区近６ 年的马尾松、红锥混交试验研究， 发现松、锥混交林在生长量、林地凋落物现存量、林地表层土壤养分含量和含水量、小气候环境， 以及林下植物物种多样性等方面均比纯松林有着明显的改善或提高， 不失为一种适宜南亚热带赤红壤丘陵水土流失区的优良混交形式，

A 6 year(1992～1997) experiment on of Pinus massoniana and Castanopsis hystris mixed forest in an eroded hilly lateric red soil area showed that the mean height growth, radial growth, individual volume increment, and stock of the mixed forest increased by 3 85%, 18 75%, 42 11% and 18 69%, respectively,as compared with these of a pure P. massoniana stand under the same conditions. Furthermore, the former had 3 1 t/hm 2 of litter standing crop, 2 48 times more than the latter. The contents of organic matter, total N and P, available N, P and K at 0～20 cm layer of the soil under the mixed forest increased by 354%, 357%, 9 5%, 73 3%, 9 9%, 15 5%, respectively, as compared with those of the pure forest. Meanwhile, the moisture contents at 0～20cm and 20～40cm layers of the soil in the mixed forest were 54 1% and 36 3%, respectively, more than in those in the pure forest, the maximum air temperature and surface temperature, the daily amplitude of air temperature and that of surface temperature in mix forest decreased by 1 6℃, 1 4℃, 1 6℃ and 2 2℃, whereas the relative humidity increased by 8 6%. The plant species and individuals in mix forest were more abundant and complicated than in the pure forest. The results indicate that mix P. massoniana with C. hystris is a suitable way for improving the pure P. massoniana forest.