不同龄组兴安落叶松林枯落物的水文效应

Hydrological Effects of Litters in Xing'an Larch Forest at Different Stand Ages

[目的] 分析大兴安岭地区不同龄组兴安岭落叶松林枯落物蓄积量持水特性，为该地区森林水文效应研究提供理论基础和重要依据。[方法] 选择不同龄组兴安落叶松天然林为研究对象，通过设置标准样地测定枯落物蓄积量，并采用浸水法测定枯落物持水特性，分析不同龄组兴安落叶松天然林枯落物水文效应。[结果] 4个龄组兴安落叶松林枯落物蓄积量变化介于28.03～34.32 t/hm^2之间，最大持水量介于87.09～109.52 t/hm^2，最大持水量表现为随着林龄增加而增加的变化趋势，且半分解层的蓄积量都大于未分解层；经统计分析，试验4个龄组兴安落叶松林枯落物未分解层、半分解层的持水量与浸泡时间之间均符合对数关系，且吸水速率与浸泡时间之间也符合指数关系；枯落物对降水的拦蓄能力总体来看，半分解层对降雨的拦蓄能力较未分解层强。[结论] 大兴安岭地区不同龄组兴安落叶松林枯落物蓄积量差异显著（除成熟林和近熟林之间），成熟林、近熟林和中林龄对于降水的拦蓄能力较幼龄林强。

[Objective] In order to provide theoretical basis for forest hydrological effect study, the experiment was conducted to investigate the growing stock and water retention capability of forest litter at different stand ages group in Daxing＇an Mountains.[Methods] We chose Xing＇an forest larch with different stand ages as the object, and set the standard sample. The method of water immersion was used to measure the water retention capability of litter. We then calculated the effective retaining content and the maximum water-holding capacity.[Results] The litter volume of four different stand age groups was from 28.03 to 34.32 t/hm^2, and the maximum water-holding capacity was from 87.09 to 87.09 t/hm^2. The maximum water-holding capacity increased with the increase of litter volume, and the maximum water-holding capacity in the half-decomposed layer was greater than that in the undecomposed layer. By statistical analysis, there was a logarithmic relationship between water capacity of undecomposed and half-decomposed layer and immersion time, and there was an exponential relationship between water absorption rate and immersion time. Overall, the rainfall interception capacity of half-decomposed layer was better than that of undecomposed layer.[Conclusion] Significant difference has been found in forest litter volume among Xing＇an larch with different ages excepting which of the mature forest and near-mature forest, the rainfall interception capacity of mature forest, near-mature forest and middle-aged forest was greater than that of young forest.