海南省两种人工林林下物种多样性与土壤水分物理性质的关系

Relationship between Plant Species Diversities and Soil Hydro-Physical Properties in Two Plantations in Hainan Province

通过测定和比较分析海南桉树人工林和橡胶人工林的林下植物多样性、土壤水分物理特性以及林下物种多样性与土壤水分物理性质的关系,结果表明:(1)桉树林下植物种类共有22种,分属14科20属,橡胶林下植物种类共有25种,分属15科22属。(2)两种森林的土壤容重总体表现为表层小于底层,表土层中桉树林的土壤容重均大于橡胶林,而中下层的土壤容重是前者小于后者;土壤总孔隙度均随深度增加呈减小趋势,在表土层中,橡胶林土壤总孔隙度大于桉树人工林,而在底土层中两种林型接近;橡胶林的毛管孔隙度随土层增加呈递减趋势,桉树林是先减小后增加;在表土层,两种林型的土壤非毛管孔隙度表现为橡胶林大于桉树林,在底土层两种林型基本一致。两种森林的土壤毛管持水量、最大持水量、土壤田间持水量、土壤排水能力均为:橡胶林大于桉树林。(3)与橡胶林相比,桉树林植物多样性与土壤物理特性相关性较小,而负相关程度较高;土壤毛管孔隙度、排水能力对桉树林下物种多样性起促进作用,而非毛管孔隙度、田间持水量起抑制作用;橡胶林物种多样性与毛管孔隙度及非毛管孔隙度呈正相关,与最大持水量、田间持水量及排水能力呈负相关。因此,橡胶林下物种多样性、土壤水分物理特性均优于桉树林,控制两种人工林林下物种多样性大小的土壤水分因子是不同的。

Plant species diversity,soil hydro-physical properties,and relationship between plant species diversity and soil hydro-physical properties in Eucalyptus plantation and Rubber plantation in Hainan Province were studied.There were fourteen families,twenty genera and twenty-two species of plants in Eucalyptus plantation and fifteen families,twenty-two genera,twenty-five species of plants in Rubber plantation.Soil bulk density of the surface layer in two plantations was less than the underlying layer.Soil bulk density of the surface soil of Eucalyptus plantation was higher than that of Rubber plantation,while in the middle and deep soil layers,the former was less than the latter.Total soil porosity in two plantations decreased from upper soil layer to deeper soil layer,and the total soil porosity of the Rubber plantations in the topsoil was greater than that in Eucalyptus plantations,and in the deeper soil layer,it was almost same in two plantations.Soil capillary porosity in the Rubber plantation decreased with the increasing of soil depth,but it first decreased and then increased in the Eucalyptus plantation.In the surface soil,soil non-capillary porosity of the Rubber plantation was greater than that of Eucalyptus plantation,but in the deeper soil layer,it＇s not different in two plantations.Maximum water holding capacity,capillary moisture capacity,field water holding capacities and discharge moisture capacity of the Rubber plantation were higher than the Eucalyptus plantation.The correlation between plant diversity and soil physical properties in Eucalyptus plantation was less than that in Rubber plantation,while as for the negative correlation the former was higher than the latter.In Eucalyptus plantation,soil capillary porosity,drainage capacity played a positive role in promoting species diversity,other than the capillary porosity,field capacity inhibiting.In Rubber plantation,non-capillary porosity and capillary porosity had the positive effect on species diversity,while the maximum water holding capacity,field water holding capacity and drainage capacity had the negative effect.Therefore,in the Rubber plantation,species diversity and soil hydro-physical properties are better the Eucalyptus plantation,and different soil hydro-physical factors of two plantations limit their own species diversities.