Duchicela Jessica, Bever James D, Schultz Peggy A
Universidad de las Fuerzas Armadas-ESPE, Departamento de Ciencias de la Vida, Sangolquí 171103, Ecuador.
Indiana University, Biology Department, Bloomington, IN 47405, USA.
Plants (Basel). 2020 Jan 7;9(1):74. doi: 10.3390/plants9010074.
The establishments of new organisms that arrive naturally or with anthropogenic assistance depend primarily on local conditions, including biotic interactions. We hypothesized that plants that rely on fungal symbionts are less likely to successfully colonize remote environments such as oceanic islands, and this can shape subsequent island ecology. We analyzed the mycorrhizal status of Santa Cruz Island, Galapagos flora compared with the mainland Ecuador flora of origin. We experimentally determined plant responsiveness and plant-soil feedback of the island flora and assessed mycorrhizal density and soil aggregate stability of island sites. We found that a greater proportion of the native island flora species belongs to families that typically do not associate with mycorrhizal fungi than expected based upon the mainland flora of origin and the naturalized flora of the island. Native plants benefited significantly less from soil fungi and had weaker negative soil feedbacks than introduced species. This is consistent with the observation that field sites dominated by native plant species had lower arbuscular mycorrhizal (AM) fungal density and lower soil aggregate stability than invaded field sites at the island. We found support for a mycorrhizal filter to the initial colonization of the Galapagos.
新生物的建立，无论是自然抵达还是在人为协助下抵达，主要取决于当地条件，包括生物相互作用。我们假设，依赖真菌共生体的植物不太可能成功定殖于偏远环境，如海洋岛屿，而这可能会塑造后续的岛屿生态。我们分析了加拉帕戈斯群岛圣克鲁斯岛植物群与原产于厄瓜多尔大陆植物群相比的菌根状况。我们通过实验确定了该岛屿植物群的植物响应性和植物 - 土壤反馈，并评估了岛屿地点的菌根密度和土壤团聚体稳定性。我们发现，与基于原产大陆植物群和该岛屿归化植物群的预期相比，该岛屿本地植物群中属于通常不与菌根真菌共生的科的物种比例更高。本地植物从土壤真菌中获得的益处明显少于外来物种，并且其负向土壤反馈也较弱。这与以下观察结果一致：在该岛屿，以本地植物物种为主的实地地点比被入侵的实地地点具有更低的丛枝菌根（AM）真菌密度和更低的土壤团聚体稳定性。我们发现有证据支持菌根对加拉帕戈斯群岛初始定殖存在过滤作用。
