The Maritime Antarctica region has terrestrial ecosystems dominated by lichens and mosses, representing important ecological indicators of climate change. However, little is known about environmental factors that shape regional cryptogam communities at local scale. In this study we analyse changes in species richness, species composition and coverage of representative cryptogam communities across a pedoenvironmental gradient in Maritime Antarctica. We hypothesized that soil texture and chemical properties shape variations in species richness and composition. We selected fifteen different pedoenvironments, where 20 plots (20 × 20 cm) were sampled for obtaining phytosociological parameters of cryptogamous communities, and in each plot a composite topsoil sample was collected to determine chemical and physical soil properties. We then evaluated the main effects of soil attributes on the richness and composition of cryptogam species using direct gradient analysis and linear models. The ecological value of species was determined, allowing to identify the type of plant community and species associations in each pedoenvironment. Differences in species composition, richness and coverage were detected along the pedoenvironmental gradient. The model analysis showed that soil fertility has significant effects on species composition, but not on species richness. Based on gradient analysis, variability on soil fertility and nutrient contents were important pedoenvironmental filters for cryptogam communities in Maritime Antarctica. This study reveals that small-scale heterogeneity contributes to specific associations along pedoenvironmental gradients. We conclude that soil attributes drive the composition pattern of cryptogam species and also the type of communities present.

中文翻译：

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南极洲海洋象岛沿土壤环境梯度的隐花藻群落的多样性和物种关联

南极洲海洋地区拥有以地衣和苔藓为主的陆地生态系统，是气候变化的重要生态指标。然而，关于在当地范围内塑造区域密码社区的环境因素知之甚少。在这项研究中，我们分析了南极洲海洋土壤环境梯度中代表性隐花植物群落的物种丰富度、物种组成和覆盖范围的变化。我们假设土壤质地和化学特性会影响物种丰富度和组成的变化。我们选择了 15 个不同的土壤环境，其中采样了 20 个地块（20 × 20 cm）以获得隐花孢子群落的植物社会学参数，并在每个地块中收集复合表土样品以确定土壤化学和物理特性。然后，我们使用直接梯度分析和线性模型评估了土壤属性对密码学物种丰富度和组成的主要影响。确定物种的生态价值，从而确定每个土壤环境中的植物群落类型和物种关联。沿土壤环境梯度检测到物种组成、丰富度和覆盖率的差异。模型分析表明，土壤肥力对物种组成有显着影响，但对物种丰富度没有影响。基于梯度分析，土壤肥力和养分含量的变异性是南极洲沿海隐花植物群落的重要土壤环境过滤器。这项研究表明，小规模的异质性有助于沿着土壤环境梯度的特定关联。