Knowledge of the genetic diversity of species in a biological community is useful for assessing the ecological and evolutionary processes that define the structure and dynamics of that community. We investigated the potential relationship between the trans-specific genetic diversity (or genetic diversity across tree species) and the diversity of tree species in a tropical subdeciduous forest. The nucleotide variation of the concatenated regions ITS 1 and ITS 3 (ITS1-3) was used to determine the trans-specific genetic diversity of 19 species of trees in five local communities at El Ocote Biosphere Reserve (REBISO), Chiapas, Mexico. Tree diversity was obtained by counting individual trees within 0.1 ha circular plots in each locality. The relationship between trans-specific genetic diversity and species diversity was established through simple linear regressions between genetic diversity parameters and community diversity. A correlation matrix was built with genetic distances (Kimura’s two-parameter model) and differences in species diversity between communities. A significant relationship was observed between nucleotide diversity (π) and species richness (Sp), and a negative association between haplotype diversity and gamma diversity (γ). Our results show species-rich and genetically diverse tree communities and a weak association between trans-specific genetic variation and species diversity in tree communities at REBISO. This research suggests a possible ecological and genetic relationship within each community. Genetic diversity values may provide an important degree of variation upon which environmental selection pressures could operate, which may be helpful to face the current environmental modifications associated with climatic change.

了解生物群落中物种遗传多样性的知识对于评估定义该群落结构和动态的生态和进化过程很有用。我们调查了跨特定物种的遗传多样性（或跨树种的遗传多样性）与热带落叶林中树种多样性之间的潜在关系。串联区域ITS 1和ITS 3（ITS1-3）的核苷酸变异用于确定墨西哥恰帕斯州El Ocote生物圈保护区（REBISO）五个地方社区中19种树的反式遗传多样性。通过对每个地区0.1公顷圆形图中的单个树木进行计数来获得树木多样性。通过遗传多样性参数和群落多样性之间的简单线性回归，建立了跨物种遗传多样性和物种多样性之间的关系。建立了具有遗传距离（Kimura的两参数模型）和群落之间物种多样性差异的相关矩阵。核苷酸多样性（π）与物种丰富度（Sp），以及单倍型多样性和γ多样性（γ）之间的负相关。我们的研究结果表明，REBISO的树种群落中物种丰富且遗传多样，而跨物种遗传变异与树种多样性之间的关联性较弱。这项研究表明每个社区内部可能存在生态和遗传关系。遗传多样性值可能会为环境选择压力提供重要的变化程度，这可能有助于应对当前与气候变化有关的环境变化。