亚热带典型人工林土壤酸化特征及其生物学机理初步分析

对亚热带典型人工林土壤pH和酸化生物学机理的研究表明:荒草地种植马尾松和木荷20年以后土壤的pH发生了变化,在0 ～ 60 cm处降低了0.12～0.47个单位；垂直方向上在距离树干10 cm处马尾松0～20cm土层pH低于木荷,20～60 cm土层pH大于木荷；水平方向上随着与树干距离的增加土壤pH受树木影响的程度逐渐降低,距离树干20 cm处土壤pH受树木的影响最大.树干茎流雨可能是树干基部附近土壤加速酸化的重要因素,根系的分布及其对盐基阳离子的吸收是造成马尾松和木荷土壤剖面出现酸化差异的主导因素.

Characteristics of soil acidification and primary study of biological mechanism of typical forest plantation in subtropical China

Studies on the soil pH and biological mechanism of typical forest plantation in subtropical China showed that the chemical properties of soil changed noticeably after the Pinus massoniana and Schima superba were planted for 20 years in waste grassland. Compared to the waste grassland, soil pH was lower 0.12-0.47 unit in Pinus massoniana and Schima superba. In the vertical direction, soil pH at the depth of 0-20 cm under Pinus massoniana was lower than that of Schima superba, while the result was contrary at the 20-60 cm layer in soil profile at 10 cm away from the main stem. In the horizontal direction, the influence of trees on soil pH became gradually weaker with the increase of distance to the main stem. Topsoil pH value was the lowest at 20 cm apart from the main stem. A lot of H+ was input to the soil near the main stem by stemflow, which may decrease topsoil pH value. The cations uptake and redistribution by the trees were the dominant mechanism of soil acidification in the soil profile, and the difference in root distribution and cations uptake between Schima superba and Pinus massoniana were main reasons for pH change in soil profiles.