Unravelling the distribution of mycorrhizal plants in the Colombian páramos

Abstract

AbstractThe tropicalpine páramo stands out as a unique biodiversity hotspot located in the northern Andes. Over the last decades, páramo plants and animals have been increasingly studied, yet a critical knowledge gap remains on their microbial ecology. Given the crucial importance of mycorrhiza in structural and functional communities, our study aimed to explore their geographic distribution in the Colombian páramos. Specifically, we used information about their host plants as a proxy and modelled their current distribution to unravel spatial patterns related to mycorrhizal status and mycorrhizal types. We constructed species distribution models for 440 vascular plant species representatives of the Colombian páramos using a combination of climatic and edaphic variables. Then we stacked the models following species classification into their mycorrhizal type: arbuscular, ectomycorrhizal, ericoid, orchid, and non-mycorrhizal. Our results suggest that the abundance of mycorrhizal species decreases with increasing elevation and in the west-to-east direction. The arbuscular type of mycorrhiza is chiefly dominant and spreads out widely throughout the Colombian páramos. The other types showed singular patterns, with (i) species having ericoid mycorrhiza being abundant in both the southern (Nariño–Putumayo) and the northern páramos (Sierra Nevada–Perijá); (ii) species with orchid mycorrhiza being abundant in the Western Cordillera and overall at low elevations, (iii) ectomycorrhizal species being absent, and (iv) non-mycorrhizal species being widely spread and reaching high elevations. Our study highlights the potentially high level of mycorrhization of this alpine system and contributes new spatial and environmental information towards a better understanding of mycorrhizal biogeography in tropical mountains.