西南山区典型森林枯落物储量及持水能力

目前西南山区枯落物水源涵养能力的研究主要集中在单点尺度上,其结果难以用于评估整个西南山区枯落物储量及持水能力。本研究整理了2004—2021年西南山区站点尺度的研究结果,对比分析了西南山区3种典型森林(共16个研究点,70个数据)枯落物储量及持水特性。结果表明: 针叶林、阔叶林、针阔混交林枯落物持水过程整体变化趋势一致,均可分为3个阶段:迅速吸水→逐渐减慢→趋于稳定。但不同森林类型各阶段吸水速率和持续时间不同,阔叶林吸水速率最快,针叶林吸水速率最慢且达到稳定时所需时间最长。不同林型枯落物储量之间差异不显著,3种林型枯落物总储量介于8.26～8.82 t·hm^-2,半分解层枯落物储量显著的空间差异性造成了枯落物总储量显著的空间差异性。3种森林枯落物总最大持水量介于17.85～19.87 t·hm^-2,枯落物最大持水率介于200.6%～228.0%。不同森林枯落物最大持水量与枯落物储量均呈显著正相关。3种森林枯落物总有效拦蓄量介于11.66～12.29 t·hm^-2,枯落物总有效拦蓄率介于128.1%～145.2%。西南山区3种林型2种分解程度枯落物储量及持水能力差异均不显著。

Litter storage and water-holding capacity of typical forests in mountainous area of Southwest China

Current studies on water conservation capacity of litter in the mountainous area of Southwest China (MASC) mainly focus on local scale. Such results are difficult to evaluate the storage and water-holding capacity of litter in the whole MASC. In this study, the results of site-scale research in the MASC from 2004 to 2021 were collated (a total of 16 research sites and 70 data), as well as the storage and water-holding characteristics of litters of three typical forests in the MASC were compared and analyzed. The results showed that the water-holding processes of litter in coniferous forest, broadleaved forest and mixed forest were similar, which could be divided into three stages: rapid water absorption, gradual slowing, and stable. The absorption rate and duration of different forests were different in each stage. The broadleaved forest had the fastest water absorption rate, while coniferous forest had the slowest with the longest duration to reach stability. There was no significant difference in litter storage among diffe-rent forest types. The total litter storage of coniferous forest, broadleaved forest and mixed forest ranged from 8.26 to 8.82 t·hm^-2. The significant spatial variations of litter storage in semi-decomposed layer resulted in that of total litter storage. The total maximum water-holding capacity of litters of the three forests ranged from 17.85 t·hm^-2 to 19.87 t·hm^-2, and the maximum water-holding rate of litter ranged from 200.6% to 228.0%. There was a positive correlation between the maximum water-holding capacity and litter storage in different forests. The total effective retention capacity of three forest litters ranged from 11.66 to 12.29 t·hm^-2, while the total effective retention rate of three forests ranged from 128.1% to 145.2%. There were no significant differences in litter storage and water holding capacity among three forest types with two decomposition degrees in MASC.