茂兰喀斯特森林不同地形植物多样性与土壤理化特征研究

为探讨不同地形植物群落物种多样性与土壤理化特征之间的相互关系。该文以茂兰喀斯特森林为研究对象,分析了不同地形植物多样性与土壤理化特征以及两者之间的相互关系。结果表明:(1)不同地形木本植物的物种组成存在差异,坡地木本植物有35科65属78种,槽谷木本植物有38科64属89种,漏斗木本植物有35科61属84种。同时,丰富度指数、多样性指数、均匀度指数大小表现为槽谷漏斗坡地;优势度指数大小表现为坡地漏斗槽谷。(2)不同地形土壤物理性质差异性显著(P0.05),其中土壤容重和非毛管孔隙度表现为坡地槽谷漏斗,自然含水量、田间持水量、总孔隙度、毛管孔隙度等指标均表现为漏斗槽谷坡地。(3)除全K外,大多数土壤养分指标表现为漏斗显著高于槽谷、坡地,即漏斗槽谷坡地。(4)冗余分析表明,植物多样性与土壤理化性质具有相关性,不同地形植物多样性指数受土壤理化性质的影响明显。以上结果旁证了茂兰喀斯特森林地形条件的复杂性和土壤理化性质的差异性是该区小生境多样、物种组成丰富的原因之一,为喀斯特森林物种多样性维持机制提供了科学依据。

Differences of plant diversity and soil physicochemical properties in Maolan karst forest under different topographic conditions

To explore the difference and relationship between plant diversity and soil physical and chemical properties in different topography of Maolan karst forest, and to provide scientific basis for the maintenance mechanism of species diversity in Maolan karst forest. The results were as follows:(1)There were differences in species composition of woody plants in different topographies. There were 78 species of woody plants belonging to 65 genera and 35 families in hillside, 89 species of woody plants belonging to 64 genera and 38 families in valley, and 84 species of funnel woody plants belonging to 61 genera and 35 families. Mean while, the magnitude of richness index, diversity index and evenness index was valley > funnel > hillside, while the magnitude of dominance index was hillside > funnel > valley.(2)There were significant differences in soil physical properties between different topographies(P < 0.05). Among them, soil bulk density and non-capillary porosity were hillside > valley > funnel, while natural water content, field water holding capacity, total porosity and capillary porosity were funnel > valley > hillside.(3)Except for total potassium(K), most soil nutrient indicators showed that funnel was significantly higher than valley and hillside, that is funnel > valley > hillside.(4)Redundancy analysis showed that plant diversity was correlated with soil physical and chemical properties, and plant diversity indexes in different topographies were significantly affected by soil physical and chemical properties. The results indicate that the complexity of topographic conditions and the difference of soil physical and chemical properties in Maolan karst forest are one of the reasons for the diversity of microhabitats and rich species composition in this area.