套种模式对水土保持效应的影响

Effects of planting models on soil and water control

在东江中上游低效水土保持林的改造中, 营建了不同套种模式的水保林,效益监测结果表明,乔灌草模式、乔灌模式和马尾松纯林模式中,以乔灌草模式的水土保持效果为最佳。乔、灌、草层分别对降水的截留和吸附,以及大量的地上枯落物具有强大的持水能力,有效地减少了雨滴直接冲刷地表,使得乔灌草模式的土壤侵蚀明显减少,套种4a后土壤侵蚀模数降为 960t/(hm2·a),约为乔灌模式的1/3和马尾松纯林的l/5;同时使土壤蓄水能力提高,土壤肥力状况得到改善。

Three models, mixed planting trees with shrubs and grass, mixed planting trees only with shrubs and the control, weretested to establish foret for soil and water control on a gu1ly erosion 1and in upper area of Dongjiang river.The effect monitoringshowed that mixed planting trees with shrubs and grass was the best treatment. Mixed planting trees with shrubs and grass increasedwater ho1ding and interception capacity by forest, increased 1itter amount on soil surface to reduce rain drop striking to soil. It alsoreduced the total amount of soil erosion. Soil erosion 4 years after planting was 960t/(km2·a), 1/3 of the soil erosion in the treatmentof mixed p1anting trees on1y with shrubs and l/5 of the soil erosion in the control.