间伐和林分类型对森林凋落物储量和土壤持水性能的影响

  目的  探讨间伐和林分类型对森林凋落物储量及土壤持水效能的影响，为提高不同林分类型水源涵养功能提供科学依据。  方法  以浙江省建德市3个小流域的间伐与未间伐杉木Cunninghamia lanceolata林和阔叶林为对象，野外采集凋落物与土壤(0~10、10~30、30~60 cm)样品，测定凋落物的储量、持水率和持水量以及土壤的容重、孔隙度和持水量。  结果  杉木林间伐较未间伐的凋落物储量降低了25.2%(P＜0.05)，而凋落物最大持水率和有效拦蓄率分别增加了24.4%和47.1%(P＜0.05)；间伐对阔叶林凋落物储量无显著影响，但凋落物最大持水量和有效拦蓄量分别比未间伐的增加了42.5%和42.2%(P＜0.05)；凋落物持水性能总体表现为间伐林分高于未间伐林分。间伐显著提高了杉木林10~60 cm土壤非毛管孔隙度和非毛管持水量(P＜0.05)；间伐显著增加了阔叶林30~60 cm土层土壤非毛管孔隙度(P＜0.05)及0~10、30~60 cm土层土壤非毛管持水量(P＜0.05)；间伐杉木林各土层土壤最大持水量均显著高于间伐阔叶林(P＜0.05)，并且间伐杉木林0~60 cm土层土壤最大持水量(3 775.19 t·hm?2)高于其他林分。  结论  间伐显著提高了森林凋落物的持水能力和土壤的持水性能，其中间伐杉木林凋落物及土壤整体的水源涵养功能最强。图3表5参考24

Effects of thinning and stand types on litter stock and soil water-holding capacity

Objective]This study aims to explore the effects of thinning and stand types on forest litter stock and soil water-holding capacity,and to provide scientific basis for evaluating water conservation function of different forest stands.Method]Two forest types(Cunninghamia lanceolata forest and broad-leaved forest)and two types of thinning(thinning C.lanceolata forest and thinning broad-leaved forest)in three small river basins in Jiande City,Zhejiang Province were taken as the research objects.Litter and soil(0-10,10-30,30-60 cm)were collected in the field,and the water immersion method was used to analyze the influence of thinning on the forest litter stock and water-holding capacity of different forest stands.Three standard plots(20 m×20 m)were selected in each forest stand for litter collection and soil sampling.The litter stock,water-holding capacity and water absorption rate,as well as the soil bulk density,porosity and water-holding capacity were determined.The statistic data of litter and soil characteristics were analyzed using one-way ANOVA and Duncan.Result]The litter stock of thinning C.lanceolata forest decreased by 25.2%(P<0.05),while the maximum waterholding rate and effective retention rate of litter increased by 24.4%and 47.1%,respectively(P<0.05).Thinning had no significant effect on litter stock in broad-leaved forests,but the maximum water-holding capacity and effective retention capacity of litter increased by 42.5%and 42.2%(P<0.05)respectively,compared with those without thinning.The overall water-holding capacity of litter in thinning forest was higher than that in normal forest.Thinning significantly increased non-capillary pores porosity and water-holding capacity of non-capillary pores in 10-60 cm soil layer of C.lanceolata forest(P<0.05).Thinning significantly increased soil non-capillary pores porosity and non-capillary water-holding capacity in 30-60 cm soil layer,as well as those in 0-10 and 30-60 cm soil layer of broad-leaved forest(P<0.05).The maximal water-holding capacity of each soil layer in the thinning C.lanceolata forest was significantly higher than that in the thinning broad-leaved forest,and the maximal water-holding capacity of 0-60 cm(3775.19 t·hm^-2)of the thinning C.lanceolata forest was higher than that of other forest stands.Conclusion]Thinning significantly improves the water-holding capacity of forest litter and soil,and the water conservation function of litter and soil in the thinning C.lanceolata forest is the strongest among the four treatments for two stands.