海南岛尖峰岭游耕农业及热带林采伐的生态后果

ECOLOGICAL CONSEQUENCES OF SHIFTING CULTIVATION AND TROPICAL FOREST CUTTING IN JIANFENGLING, HAINAN ISLAND

本文对海南岛尖峰岭半落叶季雨林带的游耕农业及热带山地雨林不同采伐方式与更新方法的生态后果进行了对比实验与调查研究。观测结果说明,游耕农业耕垦期的小气候急剧恶化,水土流失严重,涵水能力降低,地力趋向减退,撩荒期有所好转。采育择伐的更新与生态后果优于径级择伐,更显著优于皆伐。对热带森林的保护与利用对策,提出了建议。

The ecological consequences of shifting cultivation in the semideciduous monsoon forest zone and different methods of catting and regeneration in the mountain rain forest zone have been studied in Jiaruengling, Hainan Island. Permanent plots have been set up to observe the rainfall, throughfall, interception, seepage, run-off, soil fertility and microclimate. The variations after forest cutting on hilly lands and the ecological changes after shifting cultivation have been analyzed. During the cultivation period, ecological conditions worsened, and during the period out of cultivation the conditions improved. Deterioration was due to the increases in air and soil temperatures, the decrease in relative air humidity, the decreases in capability of soil water storage and soil fertility; and. the loss of soil and water. Following regeneration and the shifting of cultivation, the tending selection cutting was the best and the diameter limit cutting was better than clearcutting. Forest conservation and utilization were also discussed from point of view of soil and water loss.