中文摘要：

为了探究华北土石山区常见乔木林地枯落物的持水能力,利用2014年7月在北京密云半城子流域的油松林、侧柏林和刺槐林林下采集的枯落物,采用烘干浸泡的方法进行枯落物持水能力分析,定量比较3种林地枯落物储量,持水特性和拦蓄变化规律。结果表明：1）3种林地枯落物总储量表现为油松林（24.40 t/hm^2）〉刺槐林（19.68 t/hm^2）〉侧柏林（9.58 t/hm^2）,其总储量要高于一般林地;总厚度表现为油松林（3.57 cm）〉刺槐林（3.30cm）〉侧柏林（1 cm）。2）最大持水量表现为阔叶林高于针叶林,其中刺槐林（48.77 t/hm^2）〉油松林（40.27 t/hm^2）〉侧柏林（15.81 t/hm^2）,刺槐林与油松林差异性不显著,而侧柏与二者差异性显著。最大持水率表现出相同的规律,刺槐林（388.15%）〉油松林（276.49%）〉侧柏林（211.40%）,三者差异性极显著,其中油松林的最大持水量和持水率低于全国平均水平。3）枯落物层的持水量、吸水速率与浸水时间分别符合对数函数和指数函数,而刺槐林持水量和吸水速率较大,推断出阔叶林在集中降水条件下的蓄水能力更强。枯落物有效拦蓄量与持水功能表现一致。均为阔叶林优于针叶林,有效拦蓄量表现为：刺槐林（46.80 t/hm^2）〉油松林（38.72 t/hm^2）〉侧柏林（14.19 t/hm^2）。从枯落物总储量、最大持水量和最大持水率、有效拦蓄量等多个因素的计算判断出,半城子流域的枯落物呈现出针叶林枯落物量大但水文效应低,阔叶林量小但水文效应好的特征。因此,在林地树种配置与管理上,可以从枯落物的水文效应上考虑,提高流域林种结构的空间优化。通过研究枯落物的水文特性,可为当地造林树种选择和水源涵养生态服务评价提供理论基础和数据参考。

英文摘要：

In order to explore the water-holding capacity of forest litter in rocky mountain regions of northern China,we selected litters in three types of pure forest,i. e.,Pinus tabulaeformis,Robinia pseudoacacia and Platycladus orientalis in Banchengzi Basin,Beijing,as research objects. The litters were dried in oven and soaked in water in July 2014. At the same time,we analyzed the litter waterholding capacity and compared the litter reserves,water holding features and intercept water change in these forests. The results showed that： 1） the total amount of litters in three types of forest followed the order of Pinus tabulaeformis（ 24. 40 t / hm^2） 〉Robinia pseudoacacia（ 19. 68 t/hm^2） 〉Platycladus orientalis（ 9. 58 t / hm^2）. The total thickness of litter in Pinus tabulaeformis forest（ 3. 57 cm） was the highest,followed by Robinia pseudoacacia forest（ 3. 30 cm）,and the least was in Platycladus orientalisforest（ 1 cm）. 2） The maximum water-holding amount of broad-leaved forest was higher than that of coniferous forest,ranked as Robinia pseudoacacia forest（ 48. 77 t / hm^2）〉 Pinus tabulaeformis forest（ 40. 27 t/hm^2） 〉Platycladus orientalis forest（ 15. 81 t/hm^2）; the difference was not significant between Robinia pseudoacacia forest and Pinus tabulaeformis forest,but was significant between Platycladus orientalis forest and the other two types of forest. The maximum water-holding rate followed the order of Robinia seudoacacia forest（ 388. 15%） Pinus tabulaeformis forest（ 276. 49%） Platycladus orientalis forest（ 211. 40%）,with significant differences among them. The maximum water-holding amount and rate of Pinus tabulaeformis forest were all lower than the national average level. 3） The relationship between water absorption,water absorption rate and immersion time conformed to logarithmic function and exponential function, respectively. In the first half hour of water absorption, water absorption rate increased rapidly,and then tended to be stable over time