宁夏六盘山林区几种主要森林植被生态水文功能研究

Study on Different Forestry Vegetation's Eco-hydrological Function in Liupan Mountain of Ningxia China

从森林冠层、枯枝落叶层、土壤层等方面分析了六盘山林区水源涵养林油松、华北落叶松、辽东栎、红桦、李灌丛及杂灌丛6种森林生态系统在水文过程中的作用。试验结果表明:各植被类型的林冠层截留各不相同,在雨季(6～9月)辽东栎和华北落叶松的截留率相当,红桦的最小。各种植被类型的冠层月截留率除红桦外都是6月份最大,7,8,9三个月截留率呈波动状下降,但均为7月份的截留量最多,而红桦在6,7,8月份的截留率相当,9月份的较小;枯落物最大持水深以红桦的最大,灌丛类型的最小;土壤水文特性各异,0～80cm土层平均容重以红桦的最小,油松的最大,总孔隙度以红桦的最大,油松的最小,非毛管孔隙度以杂灌丛的最大,华北落叶松的最小,从土壤持水深看,0～80cm土层的杂灌丛土壤最大持水量最大,油松的最小;0～80cm土壤毛管持水量以华北落叶松的最大,红桦的次之,李灌丛的最小。同时对山区的降水特性进行了研究,发现降水量随海拨高度增加降水量增加,平均每100m抬升雨量5 28%,至海拨2640m以后降水量又开始下降,平均每100m递减4 27%。

The ecohydrological function of Liupan mountain forests ecosystem, which is called water restraint forests, is analyzed from the canopy interception, litter layer and soil layer. The result indicates that the canopy interception of vegetations is very different. In the rain season (6～9 months), the interception rate of Queicus liaotungensis forest and Larix principris-upper-chtii forest is almost equal and the interception rate of Betula albo-sinensis forest is minimal. The June canopy interception rate of Queicus liaotungensis forest, Larix principris-upper-chtii forest and Pinus crassifolia forest is maximum, and the July, August and September's canopy interception rate descend fluctuantly,but the June,July, August interception rate of Betula albo-sinensis forest is almost equal and the September's interception rate is minimum. The maximum holding water capacity of Betula albo-sinensis forest's litter layer is maximal and the shrub forest is minimal. The average weight per volume of 0～80 cm soil layer in the Betula albo-sinensis forest is minimal and the Pinus crassifolia forest is maximum, but the total porosity percent is reverse. Non-capillary pore percent of mixed shrub forest is maximal and Larix principris-upper-chtii forest's is minimal. The 0～80 cm maximum holding water capacity of mixed shrub forest is maximal to 477.5 mm depth and Pinus crassifolia forest is minimal to 418.8 mm depth. We also study the precipitation character of mountain and discover that precipitation will increase 5.28% when the altitude of mountain ascends one hundred meters and the precipitation reach the maximal value in the altitude of (2 640) m, but in the altitude of 2 640～2 931 m,the precipitation will decrease 4.27% per hundred meters.