Topographic complexity supports the maintenance of a high diversity of microhabitats, which may act as important ‘safe havens’ – or microrefugia – for biodiversity. Microrefugia are sites with specific environmental conditions that facilitate the persistence of species during environmental changes and exhibit unique eco-evolutionary dynamics. However, our knowledge about how topographic complexity and related eco-evolutionary selective forces influence the functional and phylogenetic signatures of species assemblages in microrefugia is very limited. Although the conceptual framework on the systematic integration of plant functional traits into the study of refugia is well established, more empirical studies on functional trait composition and functional diversity in refugia are urgently needed for more effective conservation. Here we analyzed the distribution of various plant functional traits and phylogenetic patterns in microhabitats (south- and north-facing slopes, and bottoms) of 30 large topographic depressions (i.e. doline microrefugia) and microhabitats of the surrounding plateaus in two distant forested karst regions. We found that plant assemblages in the understory of dolines and their surroundings are characterized by unique functional values and combinations of traits. Doline bottoms had the highest functional diversity among doline microhabitats and supported plant assemblages with considerably different trait compositions from the plateaus. Bottoms also had the highest phylogenetic diversity. These results suggest that topographic complexity in forested dolines has a significant effect on the distribution of plant functional traits in the understory. High functional and phylogenetic diversity in doline bottoms can have important consequences for the long-term survival of plant populations, highlighting that these microhabitats may provide a higher resilience and support an adaptive community-level response to natural and anthropogenic stressors. Understanding mechanisms that drive the survival of species within microrefugia is required to determine the best conservation and management strategies.

中文翻译：

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地形复杂性驱动微避难所林下植物群落的性状组成以及功能和系统发育多样性：保护的新见解


地形复杂性支持维持高度多样化的微生境，这些微生境可能成为生物多样性的重要“避风港”或微避难所。微型避难所是具有特定环境条件的地点，这些地点促进了物种在环境变化期间的持久性，并表现出独特的生态进化动态。然而，我们对地形复杂性和相关的生态进化选择力如何影响微避难所中物种组合的功能和系统发育特征的了解非常有限。尽管将植物功能性状系统地整合到避难所研究中的概念框架已经建立，但迫切需要对避难所的功能性状组成和功能多样性进行更多的实证研究，以实现更有效的保护。在这里，我们分析了 30 个大型地形洼地（即 doline microrefugia）的微生境（朝南和朝北的斜坡和底部）和两个遥远的森林喀斯特地区周围高原的微生境中各种植物功能性状和系统发育模式的分布。我们发现 dolines 林下及其周围环境中的植物组合具有独特的功能值和性状组合的特征。在 Doline 微生境中，Doline 底部具有最高的功能多样性，并支持与高原具有相当不同性状组成的植物组合。Bottoms 的系统发育多样性也最高。这些结果表明，森林 doline 的地形复杂性对林下植物功能性状的分布有显着影响。 doline 底部的高度功能和系统发育多样性会对植物种群的长期生存产生重要影响，突出表明这些微生境可能提供更高的复原力并支持对自然和人为压力源的适应性群落水平反应。需要了解驱动微型避难所内物种生存的机制，以确定最佳保护和管理策略。