Abstract：
The ecological and evolutionary processes shaping community structure and functions of microbial symbionts are known to be scale-dependent. Nonetheless, understanding how the relative importance of these processes changes across spatial scales, and deciphering the hierarchical metacommunity structure of fungal endophytes has proven challenging. We investigated metacommunities of endophytic fungi within leaves of an invasive plant (Alternanthera philoxeroides) across wide latitudinal transects both in its native (Argentina) and introduced (China) ranges to test whether metacommunities of fungal endophytes were structured by different drivers at different spatial scales. We found Clementsian structures with seven discrete compartments (distinctive groups of fungal species with coincident distribution ranges), which coincided with the distribution of major watersheds. Metacommunity compartments were explicitly demarcated at three spatial scales, that is, the between-continent, between-compartment, and within-compartment scales. At larger spatial scales, local environmental conditions (climate, soil, and host plant traits) were replaced by other geographical factors as principal determinants of metacommunity structure of fungal endophytes and community diversity-function relationships. Our results reveal novel insights into the scale dependency of diversity and functions of fungal endophytes, which are likely similar for plant symbionts. These findings can potentially improve our understanding of the global patterns of fungal diversity.
摘要：
已知形成微生物共生体的群落结构和功能的生态和进化过程取决于规模。尽管如此，了解这些过程的相对重要性在空间尺度上是如何变化的，并破译真菌内生菌的分层元系统结构已被证明具有挑战性。我们调查了入侵植物（空心莲子草）叶片中内生真菌的群落，该植物在其本地（阿根廷）和引进（中国）范围内的广泛的纬度样例，以测试真菌内生真菌的群落是否由不同的驱动因素在不同的空间尺度上构成。我们发现了具有七个离散区室的克莱门特结构（具有一致分布范围的独特真菌种类），这与主要流域的分布相吻合。在三个空间尺度上明确划分了元社区隔间，也就是说,大陆之间，隔间之间，和隔间内的秤。在更大的空间尺度上，当地环境条件(气候，土壤,和寄主植物性状）被其他地理因素取代，成为内生真菌的群落结构和群落多样性-功能关系的主要决定因素。我们的结果揭示了真菌内生菌多样性和功能的尺度依赖性的新见解，这可能与植物共生体相似。这些发现可能会提高我们对真菌多样性全球模式的理解。
