海南次生林与人工林林下土壤水分物理特性比较

Comparison of Soil Hydro-Physical Properties Under Secondary Forest and Artificial Forest in Hainan

为评价速生人工林的土壤环境效应,文章对比分析了海南昌江县次生林、桉树人工林和相思树人工林的土壤水分物理性质。结果表明:(1)在0~60 cm次生林土壤容重最小,其次是桉树林,相思林最大,总孔隙度、毛管孔隙度、毛管/非毛管孔隙度比值、饱和持水量、毛管持水量、田间持水量以及毛管/饱和含水量大小顺序均表现为次生林>桉树林>相思林;(2)桉树林、相思林与次生林0~60 cm土壤贮水能力相差较大;(3)3种林分间同一层土壤容重、土壤总孔隙度、毛管孔隙度、非毛管孔隙度、土壤毛管/非毛管孔隙度比值、饱和持水量、毛管持水量、田间持水量、贮水能力的方差分析结果显示,除底层达到显著差异(p<0.05)或极显著差异(p<0.01)外,其余3层均不显著,各层土壤毛管含水量/饱和含水量比值差异不显著(p>0.05);(4)3种林分土壤容重随土壤深度增大而增大,总孔隙度、毛管孔隙度、饱和持水量、毛管次生林以及田间持水量均随土层厚度增加而减少;(5)次生林的土壤容重、孔隙特征、持水性以及贮水能力随土壤深度变化,但差异均不显著(p>0.05);而桉树林和相思林的所有观测土壤物理变量的深度差异均达到极显著水平(p<0.01)或显著水平(p<0.05)。

In order to evaluate the soil environmental effects of fast-growing plantations,the soil hydro-physical properties of secondary forest,eucalyptus plantation and acacia plantation in Changjiang County,Hainan Province were compared and analyzed.The results showed that:①The soil bulk density of secondary forest was the smallest in 0~60 cm,followed by eucalyptus forest,and acacia forest was the largest.The order of total porosity,capillary porosity,capillary/noncapillary porosity ratio,saturated water holding capacity,capillary water holding capacity,field water holding capacity and capillary/saturated water content was secondary forest>eucalyptus forest>acacia forest.②The soil water storage capacity of 0~60 cm soil layer in eucalyptus forest,acacia forest and secondary forest was quite different.③The variance analysis results of soil bulk density,total soil porosity,capillary porosity,non-capillary porosity,soil capillary/non-capillary porosity ratio,saturated water holding capacity,capillary water holding capacity,field water holding capacity and water storage capacity in the same layer among the three stands showed that except for the significant difference(p<0.05)or extremely significant difference(p<0.01)in the bottom layer,the other three layers were not significant,and the ratio of capillary water content to saturated water content in each layer was not significant(p>0.05).④The soil bulk density of the three forests increased with the increase of soil depth,while the total porosity,capillary porosity,saturated water holding capacity,capillary secondary forest and field water holding capacity decreased with the increase of soil thickness.⑤The soil bulk density,pore characteristics,water holding capacity and water storage capacity of secondary forest changed with soil depth,but the difference was not significant(p>0.05).The depth difference of all observed soil physical variables between Eucalyptus forest and Acacia forest reached extremely significant level(p<0.01)or significant level(p<0.05).