东灵山油松林和辽东栎林下土壤资源和光资源的空间特征

油松林和辽东栎林是中国暖温带具有代表性的森林植被林型。为揭示油松林和辽东栎林下土壤资源和光资源的空间特征,在东灵山相应植被下各设置一条100 m样线,利用HH 2高精度土壤水分仪(美国生产)沿样线每隔1 m测定土壤水分含量,并分析相应点土壤有机质含量;利用H em iV iew林冠分析系统每隔10 m测定森林的叶面积指数、林冠覆盖度、林冠均匀性、光资源状况;采用半方差方法分析土壤水分和有机质的空间异质性。(1)油松林与辽东栎林的叶面积指数、林冠覆盖度、辐射因子和林下光资源没有显著差异,但油松林林冠均匀性显著小于辽东栎林。(2)辽东栎林的间接辐射因子与林下总辐射呈显著正相关(R2=0.466,p=0.030),而油松林的间接辐射因子与总辐射无显著相关(R2=0.203,p=0.191)。(3)光资源的数量及其组成在油松林和辽东栎林下的变化非常相似,但光资源的组成与林冠特征的关系在两种森林间存在差异。(4)油松林下土壤水分和土壤有机质含量低于辽东栎林,但异质性恰好相反;油松林下这两种因子不具有显著的空间自相关性,而辽东栎林下具有显著的空间自相关性。(5)自然条件下,10 m尺度的林下辐射强弱与土壤水分之间并不存在显著负相关。

Spatial characteristics of soil moisture and organic matter and light in Pinus tabulaeformis forest and Quercus liaotungensis forest on Dongling Mountain, Beijing, China

Pinus tabulaeformis forest and Quercus liaotungensis forest are among the most important vegetation in warm temperate region in China.In each forest,one transect of 100 m was set up in Dongling Mountain,Beijing,China and soil moisture,soil organic matter and light intensity were measured along the transects.Soil moisture and soil organic matter were measured along the transects at interval of 1 m.The HemiView Digital Canopy Analysis System was used to study leaf area index,canopy coverage,canopy uniformity,site light factors and radiation beneath canopy at interval of 10 m along transects.Semivariogram analysis and coefficient of variance(CV) were employed to reveal the spatial heterogeneity pattern of soil moisture and soil organic matter.There were no significant differences between the pine forest and the oak forests in terms of leaf area index,canopy coverage,and light intensities above and beneath canopy.The canopy uniformity of the pine forest was significantly lower than that of the oak forest.Positive correlations were found between indirect site light factor and total radiation beneath canopy in the pine forest(R~2=0.466,p=0.030),while the opposite was true in the pine forest(R~2=0.203,p=0.191).The quality and composition of the pine forest and oak forest were highly similar while the relationship between the composition of light and the canopy characters varied with forest types.Both soil moisture and organic matter in the pine forest were lower compared to oak forests and their heterogeneity in term of coefficient of variance was larger.Soil moisture and organic matter exhibited significant spatial autocorrelation in the oak forest, whereas did not in the pine forest.No significant negative relationship was found between the radiations beneath canopy and water content at the scale of 10m.