天坑森林植物群落叶功能性状、物种多样性和功能多样性特征

以天坑内部-边缘-外部森林植物群落为研究对象，通过调查植物的群落结构、叶功能性状，探究天坑内外森林植物群落叶功能性状、物种多样性和功能多样性变化特征及其内在关联，为深入了解负地形森林生态系统的功能和恢复退化喀斯特地区的植被提供一定参考。研究结果如下：（1）比叶面积（SLA: 198.75 cm2/g)）、叶面积（LA: 42.70 cm2）、叶磷含量（LPC: 1.70 g/kg）和叶钾含量（LKC: 10.27 g/kg）在天坑内部最高，叶组织密度（LTD: 0.32 g/cm3）和叶干物质含量（LDMC: 0.41 g/g）在天坑外部最高，天坑内外森林均易受到磷限制，表明随天坑内部-边缘-外部生境变化，植物对环境的适应机制和生存策略发生了部分调整，物种的防御策略增强，生长投入策略减弱。（2）Shannon-Wiener指数（2.82）、Simpson指数（0.92）和Pielou’s均匀度指数（0.87）均以天坑外部最高，功能丰富度（1.05）、功能离散度（1.88）和Rao’s二次熵（4.52）以天坑内部最高，表明随天坑内部-边缘-外部生境的变化，植物功能性状的差异减少，物种分布及其功能性状分布总体上更为均匀、物种数量增多。（3）物种多样性指数之间、功能多样性指数之间存在较强的相关性，表明物种多样性指数之间、功能多样性指数之间存在不同的制约关系。（4）叶功能性状与物种多样性、功能多样性的相关性强，物种多样性和功能多样性之间相关性较弱，表明叶性状对生态学过程的变化较为敏感，叶功能性状与物种多样性之间存在较强的耦合关系。

Leaf functional traits, species diversity and functional diversity of plant community in Tiankeng forests

To explore leaf functional traits, species diversity, and functional diversity characteristics and correlation of plant community in Tiankeng forests will help to build the context of leaf traits, species diversity, and functional diversity research context, and further understand the process and functions of the ecological system in the negative terrain forest, and provide a scientific basis for restoration and reconstruction of the vegetation in degraded karst areas. This paper takes the woody plant community in three habitats (the inside of Tiankeng, the fringe of Tiankeng, and the outside of Tiankeng) of Dashiwei Tiankeng Group as the object, to study the leaf functional traits, species diversity, functional diversity characteristics and their interactions, through community investigation and leaf functional traits measurement. The results are as follows:(1) woody plant grown in the inside of Tiankeng shows the highest specific leaf area (SLA:198.75 cm²/g), leaf area (LA:42.70 cm²), leaf phosphorus content (LPC:1.70 g/kg) and leaf potassium content (LKC:10.27 g/kg), in the outer of Tiankeng presents the highest leaf tissue density (LTD:0.32 g/cm³) and leaf dry matter content (LDMC:0.41 g/g), and the growth of woody plant is limited by P in Tiankeng forests and nearby karst forests. With the variation of habitats from the inner to the outer of Tiankeng, partial adjustments are made in the adaption mechanism and survival strategy of the woody plant. A quick defense strategy on investment for the species increases, while a slow growth strategy on investment of species is weak. (2) Shannon-Wiener index (2.82), Simpson index (0.92) and Pielou''s evenness index (0.87) in the outside of Tiankeng are the highest, and the functional richness index (1.05), function dispersion index (1.88) and Rao''s quadratic entropy index (4.52) in the inside of Tiankeng are the highest. With the variation in the inner-edge-outer habitats of Tiankeng community, the differences in plant functional traits reduce, the range of species distribution and functional traits are steady, and the individual of species increases. (3) There is significantly correlated to each species diversity and functional diversity, indicating that there are different restrictive relationships between species diversity and functional diversity. (4) The leaf functional traits are significantly correlated with species diversity and functional diversity, and the correlation between species diversity and functional diversity is weak, indicating that leaf traits are more sensitive to variation of ecological processes and there is a strong coupling relationship between leaf functional traits and species diversity.