大青山不同植被类型保育土壤能力

Soil Conservation Capacity of Different Types of Vegetations in Daqing Mountain,Inner Mongolia

采用人工模拟降雨的方法研究了不同植被类型枯落物层和土壤层对降雨产流量的阻滞作用,从而揭示其保育土壤的能力。结果表明:在0.80～0.85 mm/min降雨强度下,不同植被类型的产沙量由大到小依次为,未封育荒草坡、油松幼龄林、已封育荒草坡、油松中龄林、虎榛子阳坡灌丛、白桦幼龄林、白桦中龄林、油松近熟林、虎榛子阴坡灌丛、白桦近熟林;在0.60～0.65 mm/min降雨强度下则为,未封育荒草坡、油松幼龄林、已封育荒草坡、白桦幼龄林、油松中龄林、虎榛子阳坡灌丛、虎榛子阴坡灌丛、油松近熟林、白桦中龄林、白桦近熟林。同一植被类型枯落物层、土壤层滞水量及保土能力均与模拟降雨强度呈反比,不同植被类型保育土壤能力由大到小为,白桦天然次生林、油松人工林、虎榛子灌丛、荒草坡。

An experiment was conducted to study the obstructing effect of litter layer and soil layer for differem types of vegeta- tions on rainfall runoff volume by the method of artificial simulation of rainfall, aiming to discuss the soil conservation ca- pacity of different types of vegetations. Results showed that, under the rainfall intensity of 0.80-0.85 mm/min, the sedi- ment yield of non-enclosed barren grassland slope was highest, followed by young Pinus tabuliformis forest, enclosed barren grassland slope, middle-aged P. tabuliformis forest, Ostryopsis davidiana shrublands on sunny slope, young Betula platyphylla forest, middle-aged B. platyphylla forest, near mature P. tabuliformis forest, O. davidiana shrublands on shady slope, and near mature B. platyphylla forest; under rainfall intensity of 0.60-0.65 mm/min, the sediment yield of non-enclosed barren grassland slope was highest, followed by young P. tabuliformis forest, enclosed barren grassland slope, young B. platyphylla forest, middle-aged P. tabuliformis forest, O. davidiana shrublands on sunny slope, O. da- vidiana shrublands on shady slope, near mature P. tabuliformis forest, middle-aged B. platyphylla forest, and near mature B. platyphylla forest. The water retention capacity and soil conservation capacity of litter layer and soil layer for the same type of vegetations were both inversely proportional with simulated rainfall intensity. The soil conservation capacity of natu- ral B. platyphylla secondary forest was highest, followed by P. tabuliformis plantation, O. davidiana shrublands, and bar- ten grassland slope.