不同等级石漠化地区植物群落物种多样性及优势种叶片性状对环境因子的响应

Response of plant community species diversity and leaf traits of dominant species to environmental factors in different grades of rocky desertification areas

关键词:  石漠化程度, 群落动态, 植物排序, 冗余分析, 贵州

Key words:  rocky desertification degree, community dynamics, plant ordination, redundancy analysis, Guizhou Province

摘要:

为探讨不同等级石漠化对植物群落物种多样性和优势种叶片性状的变化规律及其对环境因子的响应,该研究以无、轻度、中度和重度石漠化地区植物群落为对象,通过Shannon-Wiener多样性、Margalef丰富度、Pielou均匀度和Simpson多样性等指数以及优势种LA、LT、LDMC和 SymboldA@ ¹³C等叶片性状分析了石漠化梯度上的物种多样性和叶片性状变化规律。结果表明:36个样方共有维管植物188种,隶属69科141属。随着石漠化程度加剧,各物种多样性指数总体呈现下降趋势; 不同等级石漠化物种多样性差异:乔木层>灌木层>草本层。优势种LA随着石漠化程度的加剧呈现降低趋势,而LT、LDMC和 SymboldA@ ¹³C呈现升高趋势,不同等级石漠化优势种叶片性状具有显著差异(P<0.05)。结合CCA分析表明,土层厚度和土壤含水量是影响石漠化地区植物空间分布最主要的影响因素; 通过RDA分析显示,物种多样性指数与环境因子之间具有显著相关关系,其中速效钾、土壤含水量、碱解氮、土层厚度和有机质是影响物种多样性和优势种叶片性状的主导因素。这对西南喀斯特植被生态保护和石漠化生态系统植被恢复具有一定的理论意义和指导价值。

Abstract:

In order to find out the change rule of different grade rocky desertification(RD)on plant community species diversity and leaf traits of dominant species, and to explore its response to environmental factors. Taking plant communities in non, slight, moderate and intense RD areas as research objects, the species diversity and leaf traits change rule on RD gradient were studied by diversity indices such as Shannon-Wiener diversity, Margalef richness, Pielou evenness and Simpson diversity, and leaf traits of dominant species such as LA, LT, LDMC and SymboldA@ ¹³C. The results showed that there were 188 vascular plants belonging to 69 families and 141 genera in 36 plots. As the degree of RD intensifies, the diversity index of each species generally showed a downward trend; The diversity of RD species in different grades was arbor layer > shrub layer > herb layer. The dominant species LA decreased with the increase of RD degree, while LT, LDMC and SymboldA@ ¹³C showed an increasing trend, and the leaf traits of dominant species of different RD grades were significantly different(P<0.05). Combined with CCA analysis, soil thickness(ST)and soil water content(SWC)were the most important factors affecting the spatial distribution of plants in RD areas; Through RDA analysis, there was a significant correlation between species diversity index and environmental factors, among which available K(AK), SWC, available nitrogen(AN), ST and soil organic matter(SOM)were the dominant factors affecting species diversity and leaf traits of dominant species. The research results had certain theoretical significance and guiding value for the ecological protection of southwest karst vegetation and vegetation restoration of RD ecosystem.