杉木天然林和人工林涵养水源功能研究

Studies on the Water Conservation Functions of Cunninghamia lanceolata Natural Forest and Plantation

通过对杉阔天然混交林、天然杉木林和杉木人工林的林冠层、林下植被层、枯枝落叶层和土壤层水源涵养功能的研究,结果表明:两种天然林总持水量分别比人工林高699 18t·hm-2和337 67t·hm-2,天然林具有更好的涵蓄水分功能。林分不同层次的持水量大小顺序为:土壤层>枯枝落叶层>林冠层>林下植被层,土壤层是森林涵蓄降水的主要场所,其贮水量占林分总贮水量的90%以上。天然林地上部分各层次的持水量分配较为均匀,而杉木人工林林冠层持水量大大高于林下植被和枯枝落叶层的持水量,这种结构不利于削弱林内降雨侵蚀力,土壤也较为板结,渗透功能较差。

The results show that the total waterholding capacities of Cunninghamia lanceolata and broadleaved natural mixed forest and natural C.lanceolata forest are 69918t/hm2 and 33767t/hm2 higher than the plantation total waterholding capacity,the natural forest possesses the better function of conserving and depositing the water.The waterholding capacity of the soil layer is >that of the litter layer>that of the canopy layer>that of the vegetation layer under the stands,the soil layer is the place for forest's conserving and depositing the precipitation,the waterholding capacity accounts for 90% and more of the total waterholding capacity.The waterholding capacity distribution to every natural forest layers above the ground is relatively uniform,whereas the canopy layer waterholding capacity of C.lanceolata plantation is greatly higher than the waterholding capacities of undervegetation and litter layer So protecting the natural forests in our province possesses the important significance for reducing flood and waterlogging calamities.