大青山不同植被下的地表径流和土壤侵蚀

Surface runoff and soil erosion of different vegetations in Daqing Mountain,Inner Mongolia

该文以内蒙古大青山6种植被为对象,在不考虑林冠层作用的条件下,于2006—2007年用人工降雨方法,以地表径流和土壤侵蚀为指标,研究不同植被条件下地表的产流产沙状况,并就降雨因子、坡度、凋落物、地被物、土壤等因子与产流产沙的相关性进行探讨,以期为大青山生态环境建设和植被恢复与保护提供依据。结果表明:①4种林地间凋落物特性和土壤物理特性差别较大,白桦山杨林的减流减沙功能最好,落叶松林次之,油松林最差;②6种植被的水土保持功能不同,差别较大,产沙量大小依次为油松林>未封育荒草坡地>落叶松林>虎榛子林>已封育荒草坡地>白桦山杨林,油松林的产沙量是白桦山杨林的21.8倍;③坡度、降雨强度和降雨量对产流产沙影响较大,随坡度、降雨强度和降雨量的增大而增加;④降雨季节不同,产流量也不同,主要取决于活地被物层干燥度和凋落物层自然含水率;⑤对于荒草坡地,产流量与坡度和降雨量相关性较大,产沙量与径流量和降雨量相关性较大;对于森林植被,产流量与凋落物厚度和降雨量相关性较大,产沙量与径流量和凋落物厚度相关性较大。

In order to provide some useful information for construction of environment and restoration and protection of vegetation, by artificial rainfall trial, surface runoff and soil erosion were chosen as measurement indices to study runoff-sediment-yielding characteristics about six vegetations without regard to the function of canopy interception in Daqing Mountain, Inner Morgolia during 2006--2007. In the experiment, rainfall factors, gradient, litter, vegetation coverage and soil were examined. The correlation between the listed effect factors and surface runoff, soil erosion was also discussed. The results show： 1 ） There were differences on the soil physical characters and litter characters in four kinds of forests and their sequence was mixed forest of Betula platyphyUa and Populus davidiana 〉 Larix principis-rupprechtii forest 〉 Ostry opsisdavidiana shrub 〉 Pinus tabulaeformis forest. 2 ） The function of controlling soil erosion was different in six vegetations and the sequence of sediment production was P. tabulaeformis forest 〉 unenclosed waste grassland 〉 L. principis- rupprechtii forest 〉 O. opsisdavidiana shrub 〉 enclosed waste grassland 〉 mixed forest of B. platyphyUa and P. davidiana and the amount of P. tabulaeformis forest was 21.8 times larger than that of mixed forest of B. platyphylla and P. davidiana. 3）The gradient, rainfall amount and rainfall intensity had great effects on surface runoff and soil erosion and the amount of surface runoff and soil erosion was increased with the augment of gradient, rainfall intensity and rainfall amount. 4） The amount of surface runoff was different in distinct rainfall season, which mainly depended on the natural water content of litter layers and the dryness degree of live cover layers. 5） For waste grassland, the runoff amount was highly correlated with gradient and rainfall and the soil erosion amount was highly correlated with runoff and rainfall. For forest vegetation, the runoff amount was highly correlated with thickness of litter and rainfall and the soil erosion amount was highly correlated with runoff amount and thickness of litter.