宁夏六盘山南侧森林枯落物及土壤的水文生态功能研究

Study on Eco-hydrological Function of Forest-litter and Soil in the South Side of Liupan Mountains,Ningxia Hui Autonomous Region,China

森林枯落物和土壤具有重要生态水文功能,对六盘山香水河小流域的辽东栎—少脉椴、华北落叶松林的研究表明:辽东栎—少脉椴林枯落物未分解层、半分解层的最大持水量分别为5.42、11.28 t.hm-2;华北落叶松林的对应值分别为5.72、24.51 t.hm-2。两种林分枯落物的有效拦蓄量分别为0.56和1.63 mm,即华北落叶松林枯落物的持水能力好于辽东栎—少脉椴林。但辽东栎—少脉椴林1 m土层的非毛管持水深和毛管持水深(108.15、441.02mm)远大于华北落叶松林(65.80、420.00 mm),且前者生长季1 m土层有效持水能力(267.77-327.42 mm)大于后者(133.55-227.23 mm)。从林地综合持水能力来看,辽东栎—少脉椴林的水文生态功能优于华北落叶松林。此外发现,虽然是两个不同的林分,但其1 m土层的有效持水能力的非毛管比例都是36.6%,毛管比例都是63.4%,表明在采用土壤有效持水能力、毛管贮水深、非毛管贮水深这3个指标中的任何一个评价较厚土层的总持水能力时,都将有很好的一致性。

To study the eco-hydrological function of litter and soil, a natural mixed forest of oak （ Quercus liaotungensis） and linden （Tilia paucicostata） and a plantation of larch （Larix principis-rupprechtii） in the small watershed of Xiangshuihe in south side of Liupan Mountains of Ningxia Hui Autonomous Region were selected as research stands. The results showed that： the un-decomposed （0l） and semi-decomposed litter（Of） had a water holding capacity of 5.42 and 11.28 t·hm^-2for the mixed stand, 5.72 and 24.51 t·hm^-2for the larch forest. The effective water holding depth of litter layer of these two stands were 0.56 and 1.63 mm respectively. It meaned that the litter＇ s capability of water holding For larch plantation was better than that of the mixed stand. The water holding capacities of non-capillary pores and capillary pores of 1 m soil layer were 108. 15 and 441.02 mm for the mixed stand, obviously higher than those for the larch forest （65.80 and 420.00 mm）. Moreover, the effective water holding capacity of 1 m soil layer for growing season varied between 267.77 - 327.42 mm for the mixed stand, also higher than those for larch forest（ 133.55 - 227.23 mm）. As a whole, the eco-hydrological function of forest soil of mixed stand was better than that of the larch forest. In addition, it was found that the non-capillary ratio and capillary ratio in the effective water holding capacity of 1 m soil layer were 36.6% and 63.5% for both stands. This meaned that the effective soil water holding capacity, non-capillary water holding capacity, capillary water holding capacity had the equal power as indicator in evaluating the water holding capacity of a thicker soil layer.