In temperate mixed forests, dominant ectomycorrhizal (EM) tree species usually coexist with diverse arbuscular mycorrhizal (AM) understorey tree species. Here, we investigated the spatial associations between AM and EM trees in two > 20 ha temperate forest mega‐plots to better understand the observed ‘EM‐dominant versus AM‐diverse’ coexistence. Overall, we found that positive spatial associations (e.g., facilitation) were mostly related to EM trees, while negative spatial associations (e.g., inhibition) were mainly related to AM trees. Because adult EM trees tended to facilitate surrounding AM and EM saplings and other EM adults in these two forests, facilitation hotspots that stabilize AM‐EM tree coexistence should be centred around EM tree species rather than around AM tree species. Together, we propose a novel EM‐stabilization mechanism, which emphasises how, despite some species‐specific variation, EM tree species foster ‘EM‐dominant versus AM‐diverse’ coexistence in temperate mixed forests by facilitating other trees.

中文翻译：

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菌根类型调节温带森林中的树木空间关联：外生菌根树可能有利于物种共存


在温带混交林中，优势的外生菌根 （EM） 树种通常与不同的丛枝菌根 （AM） 林下树种共存。在这里，我们研究了两个 > 20 公顷温带森林巨型样地中 AM 和 EM 树之间的空间关联，以更好地了解观察到的“EM 优势与 AM 多样化”共存。总体而言，我们发现正空间关联 （例如，促进） 主要与 EM 树相关，而负空间关联 （例如，抑制） 主要与 AM 树相关。由于成年 EM 树倾向于促进周围的 AM 和 EM 树苗以及这两个森林中的其他 EM 成虫，因此稳定 AM-EM 树共存的促进热点应以 EM 树种为中心，而不是以 AM 树种为中心。我们共同提出了一种新的 EM 稳定机制，该机制强调尽管存在一些物种特异性变化，但 EM 树种如何通过促进其他树木在温带混交林中促进“EM 优势与 AM 多样性”共存。