关键词：
间伐;穿透雨;树干茎流;华北落叶松;宁夏六盘山
摘 要：
量化间伐强度和林分特征对降雨分配的影响,可为基于水文基础的森林管理提供科学依据。利用传统水文学方法,在宁夏六盘山香水河小流域华北落叶松人工林设置4个间伐强度的处理与未经过间伐的对照林分,进行穿透雨、树干茎流对比。结果表明:研究期间总降雨量为507.2 mm,华北落叶松对照林分穿透雨量为56.6%,穿透雨量随着间伐强度增大而增大,分别占总降雨量的62.1%、60.9%、68.6%和74.5%;树干茎流量随着间伐强度增大而减小,分别占总降雨量的0.91%、0.73%、0.54%、0.37%和0.36%;与对照相比,截留量分别减少5.3%、4.0%、11.5%和17.3%。穿透雨量与叶面积指数、郁闭度、胸高断面积和林分密度都呈线性负相关,这些变量和总降雨量形成的指数方程(T=Rea X)可以很好地模拟穿透雨量(R2=0.95)。华北落叶松林为30年左右时,间伐强度为43.0%~53.4%(林分密度844~1 033株/hm2)是增加六盘山地区华北落叶松穿透雨量的最优范围,有利于实现林分结构稳定和区域用水安全等多重要求。
译 名：
Effects of thinning intensity on throughfall and stemflow of Larix principis-ruprecitii plantations
作 者：
CAO Gongxiang;WANG Yunni;WANG Yanhui;XU Lihong;JI Meng;Inner Mongolia Academy of Forestry Science;Research Institute of Forest Ecology,Environment and Protection,Chinese Academy of Forestry,Key Laboratory of Forestry Ecology and Environment of the State Forestry Administration;
单 位：
CAO Gongxiang%WANG Yunni%WANG Yanhui%XU Lihong%JI Meng%Inner Mongolia Academy of Forestry Science%Research Institute of Forest Ecology,Environment and Protection,Chinese Academy of Forestry,Key Laboratory of Forestry Ecology and Environment of the State Forestry Administration
关键词：
thinning;;throughfall;;stemflow;;Larix principis-ruprecitii plantation;;Liupan Mountains in Ningxia
摘 要：
[Background] Quantifying the effects of different forest thinning intensities and stand structure on the partitioning of rainfall aims at providing scientific evidences in the forest management based on hydrology. [Methods] The designed experiment included 5 plots with the same slope orientation in a small catchment named Xiangshuihe of Liupan Mountains,Ningxia. All of the plots,with equal areas of 30 m × 30 m,were on a slope and were laid out in a homogeneous Larix principisruprecitii plantation. One plot was not thinned and the other plots were thinned at four different intensities: 14. 1%,37. 4%,43. 0% and 53. 4%,respectively. Twenty throughfall collectors( diameter20 cm) for each plot were mechanically arranged and the throughfall under canopy in each rainfall eventwas collected from May to October 2012. Stemflow was also measured in each rainfall event in the growing season of 2012. In each treatment,2 diameter classes were defined after thinning,and one representative sample tree per diameter class was selected for each. The bark on each sample tree was scraped off to smooth the surface in preparation for the fitting of a plastic collar. After the plastic collars were attached,plastic tubes were inserted into small holes located in the lowest part of the collars to collect the water in containers. The throughfall and stem-flow,was measured 17 times during the experiment time. Differences in the accumulated values of throughfall and stemflow among the treatments were analyzed with ANOVA. [Results]During the experiment period,the bulk rainfall was 507. 2 mm,and the throughfall of L. principis-ruprecitii plantation in the control accounted 56. 6% of total precipitation; whereas throughfall increased significantly with the increase of thinning intensity,and was62. 1%,60. 9%,68. 6% and 74. 5% of the bulk rainfall,respectively corresponding to the thinning intensity of 14. 1%,37. 4%,43. 0% and 53. 4%. Stemflow decreased significantly with the increase of thinning intensity, and was 0. 91%,0. 73%,0. 54%,0. 37% and 0. 36% of the bulk rainfall,respectively corresponding to the thinning intensity of 14. 1%,37. 4%,43. 0% and 53. 4%. The canopy interception decreased 5. 3%,4. 0%,11. 5% and 17. 3%, respectively while compared with the control. Total throughfall was negatively and linearly correlated to the leaf area index,forest coverage,basal area,and tree density. In contrast,throughfall was modelled by considering these variables together with bulk rainfall in a multiple exponential expression( T = Rea X),which simulated the throughfall with R2= 0. 95. [Conclusions]The results and prediction accuracy of the model may offer scientific basis for forest management based on hydrological basis. When the L. principis-ruprecitii was about 30 a,the thinning intensities was 43. 0%-53. 4%( Stand density: 844-1 300 Trees/hm2) was the optimal range for increasing the throughfall in Liupan Mountains. Such ideal stand structure will be conducive to realizing the multiple goals,including the stable stand structure and regional water safety.
