抚育间伐对麻栎次生林枯落物持水性的影响

Effects of Thinning on Litter Water Holding Capacity of Quercus acutissima Secondary Forest

抚育间伐作为森林经营的一项重要手段,能够影响枯落物持水性能。以桥山林区麻栎次生林为对象,通过典型取样法、烘干法、浸泡法,探讨了不同间伐强度(未间伐、间伐15%—轻度间伐、间伐25%—中度间伐、间伐35%—重度间伐)对样地内枯落物持水效应的影响。结果表明:(1)间伐使枯落物总储量减少,随着间伐强度提高分解层储量先增多后减少,中度间伐时最多(3.833t/hm^2),轻度间伐次之(21.838t/hm^2);(2)轻度间伐下枯落物最大持水量最高(7.60mm),重度间伐强度下最小(6.21mm);(3)轻度间伐下枯落物总有效拦蓄量及分解层有效拦蓄量都最大,分别为56.79,38.56t/hm^2,未分解层有效拦蓄量为18.21t/hm^2,仅次于未间伐样地(22.59t/hm^2);(4)不同间伐强度下枯落物吸水速率随浸水时间的增加逐渐减小,且两者均显著相关,轻度间伐强度下吸水速率均最大。以上结果表明,轻度间伐能提高麻栎次生林枯落物持水性能,可为桥山林区麻栎次生林森林抚育间伐提供参考。

As an important means of forest management,thinning can affect the water holding capacity of litter.In order to evaluate the relationship between thinning intensity and the water-holding capacity of litter layer,the natural secondary Quercus acutissima of Qiaoshan Mountains in the south area of the Loess Plateau was used as our study area.Three plots with thinning intensities of 15%,25%and 35% were established and plot that have not been thinned was selected as the control check（CK）.The typical sampling method,drying method,soaking method were used to examine the effect of thinning intensity on the water-holding capacity of litter layer.The results showed as the follows.（1）the thinning reduced the total litter reserves,with the increase of the thinning intensity,the amount of the decomposed layer increased firstly and then decreased,the middle thinning（3.833 t/hm^2）being the most and following the light thinning（21.838 t/hm^2）;（2）under light thinning,the maximum water-holding capacity of the litter was the highest（7.60 mm）and it was the lowest under the heavy thinning（6.21 mm）;（3）light thinning plot saw the highest number of modified interception in litter layer（56.79 t/hm^2）and in decomposed layer（38.56 t/hm^2）and the second highest number in un-decomposed layer（18.21 t/hm^2）;（4）the water-absorbing rate was significantly correlated in all three thinning plots.In conclusion,light thinning can improve water-holding capacity of the natural secondary Quercus acutissima.The conclusion can be used as reference for the close-to-nature management of secondary forest of Quercus acutissimain Qiaoshan forest zone.