晋西黄土区典型林分枯落物层水文生态特性研究

选择山杨栎类次生林（以下简称次生林）、刺槐林、侧柏林、油松林为研究对象,通过样地调查,结合室内浸泡方法,对比分析枯落物（未分解层、半分解层）的水文特征指标,研究典型林分枯落物层水文生态特性。结果表明：（1）枯落物厚度为3.93~4.95 cm,刺槐林最大,油松林最小;蓄积量为次生林最大（19.28 t/hm²）,侧柏林（18.03 t/hm²）和刺槐林（17.57 t/hm²）次之,油松林最小（14.73 t/hm²）,未分解层蓄积量小于半分解层。（2）枯落物最大持水量（率）为30.92~61.31 t/hm²（197%~320%）,次生林最大,依次为刺槐林、侧柏林,最小为油松林。（3）枯落物有效拦蓄存在显著差异（P>0.05）,表现为次生林（31.29 t/hm²） > 刺槐（22.20 t/hm²） > 侧柏（18.19 t/hm²） > 油松（13.94 t/hm²）,有效拦蓄率为107%~173%。（4）在浸水2 h内,枯落物持水量和吸水速率变化以次生林与刺槐林最为迅速,半分解层较未分解层变化迅速;持水过程中,两者与时间分别呈对数函数（R²>0.89）和幂函数关系（R²>0.99）。在4种林地中,次生林林下枯落物水文生态潜力最优,油松纯林最差,表现为次生林 > 刺槐 > 侧柏 > 油松。刺槐是除次生林外的3种人工林中最优林种。建议研究区内合理优化恢复树种配置,以提高水文生态功能。

Hydrological and Ecological Characteristics of Typical Stand Litter Layer in the Loess Region of Western Shanxi Province

In this paper, the secondary forests of Populus and Quercus (hereinafter referred to as secondary forests), Robinia pseudoacacia forest, Platycladus orientalis forest, and Pinus tabulaeformis forest were selected as the research objects. Through sample survey and indoor immersion method, to compare and analyze the hydrological characteristics of litter (undecomposed layer, semi-decomposed layer), and study the hydrological and ecological characteristics of litter layer in typical forest stands. The results showed that: (1) The thickness of litter is 3.93 to 4.95 cm. The largest was R. pseudoacacia forest, and the smallest was P. tabulaeformis forest.The largest volume was secondary forest (19.28 t/hm²), followed by P. orientalis forest (18.03 t/hm²) and R. pseudoacacia forest (17.57 t/hm²), the smallest was P. tabulaeformis forest (14.73 t/hm²).The accumulation of undecomposed layers was less than that of semi-decomposed layers. (2) The maximum water holding capacity (rate) of litter was 30.92 to 61.31 t/hm² (197% to 320%), the secondary forest was the largest, followed by R. pseudoacacia forest, P. orientalis forest, and the smallest was P. tabulaeformis forest. (3) There was a significant difference in effective storage of litters (P>0.05), which was represented by secondary forest (31.29 t/hm²) > R. pseudoacacia (22.20 t/hm²) > P. orientalis (18.19 t/hm²) > P. tabulaeformis (13.94 t/hm²). The effective storage rate was 107% to 173%. (4) Within 2 hours of immersion, the water holding capacity and water absorption rate of litter in secondary forest and black locust forest changed most rapidly. The semi-decomposed layer changed faster than the undecomposed layer. In the process of holding water, the two had logarithmic function (R²>0.89) and power function relationship (R² > 0.99) with time. Among the four types of forest land, the hydrological potential of litter in secondary forests was the best, and that of pure P. tabulaeformis forest was the worst. The potential of hydrological characteristics was secondary forest > R. pseudoacacia > P. orientalis > P. tabulaeformis. R. pseudoacacia was the best forest species among the three plantations except secondary forest. It is recommended to reasonably optimize the restoration of tree species allocation in the study area to improve hydrological and ecological functions.