天全县几种退耕还林类型林地土壤理化性质年际动态变化研究

Dynamic Variation of Physical and Chemical Properties of Soil in Different Patterns of Returning to Forest

研究了四川盆周山地几种不同退耕还林类型（三倍体毛白杨林、桤木林、杉木林、杂交竹林）下0-40cm土层的物理性质和化学性质2002-2005年的年际变化动态，结果表明：不同类型林分林地土壤的理化性质都得到了很大程度的改善，其变化的程度是：杉木林〉三倍体毛白杨林〉桤木林〉杂交竹林，且基本上都是土壤上层变化大于土壤下层。这说明，不同的植被类型对土壤的改良作用也是有明显区别的，不同退耕还林模式下的林地土壤理化性质与林地的林分类型有明显的相关性。另外，通过对土壤理化性质进行纵向比较可以看出，在退耕还林初期（前5年），不同类型林分对土壤的改良速率是有明显差异的，总体表现为：杉木林〉三倍体毛白杨林〉桤木林〉杂交竹林。

Study on dynamic changes of 0 - 40 cm soil physical properties and chemical properties from 2002 to 2005 in different patterns of turning to forest in hills of Sichuan basin resulted that both the physical and chemical properties improved as follows： Chinese fir 〉 triploid Populus tomentosa 〉 Alnus cremastogyne 〉 bamboo, and the first layer （0 - 20 ） improved better than the second layer （20 - 40 ）, which meant that different vegetation types had different effect on soil improvement and had obvious correlation to the soil＇s physical and chemical properties. Moreover, comparison on the soil＇s physical and chemical properties from 2002 to 2005, indicated that in the first 5 years, soil improvement rate had difference as follows： Chinese fir 〉 triploid P. tomentosa 〉 Alnus cremastogyne 〉 bamboo.