低效林改造对土壤理化性质及水源涵养功能的影响

Effects of reconstruction of low-benefit stands on the soil physical and chemical properties and water conservation function

通过调查分析广西苍梧县低效马尾松、湿地松纯林经采取异龄混交荷木、大叶栎等阔叶树种的改造措施后土壤理化性状及水源涵养功能,表明：1）低效林改造后,林地土壤养分含量得到提高,土壤物理性状得到改善;2）林地土壤水分状况和渗透性能得到显著提高;3）与低效马尾松纯林（2 166 t/hm2）和湿地松纯林（2 075 t/hm2）相比,马尾松＋荷木、湿地松＋荷木和湿地松＋大叶栎林地土壤蓄水量显著提高,分别达到2 543、2 506和2 483 t/hm2;4）0~20 cm土层土壤理化性状改善幅度大于20~40 cm土层。低效林混交荷木、大叶栎后,改造效果明显,是低效林改造措施之一。

Soil physical and chemical properties and water conservation function of five forest stands was investigated in Changwu County,Guangxi Province,including two low-benefit stands（Pinus massoniana stand and Pinus elliottii stand）,and three reformed mixed stands（mixed stand of Pinus massoniana and Schima superba,mixed stand of Pinus elliottii and Schima superba,mixed stand of Pinus elliottii and Castanopsis fissa）.The results show as the follows： 1） Compared with low-benefit stands,reformed mixed stands show a significant increase in soil mineral elements contents and physical properties.2） The water status and soil percolation capacity have a significant increase in reformed mixed stands than that in low-benefit stands.3） Compared with Pinus massoniana stand（2166t/hm2） and Pinus elliottii stand（2075t/hm2）,there are significant improvement in water conservation function in reformed mixed stands.The water storage amount of mixed stand of Pinus massoniana and Schima superba is 2543t/hm2,2506t/hm2 in the mixed stand of Pinus elliottii and Schima superba,and 2483t/hm2 in the mixed stand of Pinus elliottii and Castanopsis fissa.4） Magnitude of the increases of soil physical and chemical properties vary with soil depth,being larger in the 0-20cm layer than 20-40cm layer.Soil nutrition,physical properties and water conservation function are significantly improved in three reformed mixed stands.It is one of the effective measures to reconstruction for low-benefit stands that Schima superba or Castanopsis fissa is planted in low-benefit stands.