Tree planting and natural regeneration contribute to the ongoing effort to restore Earth's forests. Our review addresses how the plant microbiome can enhance the survival of planted and naturally regenerating seedlings and serve in long-term forest carbon capture and the conservation of biodiversity. We focus on fungal leaf endophytes, ubiquitous defensive symbionts that protect against pathogens. We first show that fungal and oomycetous pathogen richness varies greatly for tree species native to the United States ( n = 0–876 known pathogens per US tree species), with nearly half of tree species either without pathogens in these major groups or with unknown pathogens. Endophytes are insurance against the poorly known and changing threat of tree pathogens. Next, we review studies of plant phyllosphere feedback, but knowledge gaps prevent us from evaluating whether adding conspecific leaf litter to planted seedlings promotes defensive symbiosis, analogous to adding soil to promote positive feedback. Finally, we discuss research priorities for integrating the plant microbiome into efforts to expand Earth's forests.

中文翻译：

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通过植物微生物组促进重新造林：来自植物圈的视角

植树造林和自然更新有助于持续恢复地球森林。我们的综述探讨了植物微生物组如何提高种植和自然再生幼苗的存活率，并有助于长期森林碳捕获和生物多样性保护。我们专注于真菌叶内生菌，这是普遍存在的防御性共生体，可以抵御病原体。我们首先表明，美国本土树种的真菌和卵菌病原体丰富度差异很大（每个美国树种 n = 0-876 种已知病原体），近一半的树种要么没有这些主要类群的病原体，要么带有未知病原体。内生菌是抵御鲜为人知且不断变化的树木病原体威胁的保险。接下来，我们回顾了植物叶际反馈的研究，但知识差距使我们无法评估向种植的幼苗中添加同种落叶层是否会促进防御共生，类似于添加土壤以促进正反馈。最后，我们讨论了将植物微生物组整合到扩大地球森林的努力中的研究重点。