Unexpectedly High Beta-Diversity of Root-Associated Fungal Communities in the Bolivian Andes

Abstract

Bolivia is one of the most biologically diverse countries on the planet. Between the Andes and the Amazon drainage basin spans the Yungas, a vast forested region shown to be extremely species rich in macro-organisms. However, it remains unclear whether this high diversity is also reflected in microbial diversity. Here we assess the genetic, taxonomic and functional diversity of root-associated fungi surrounding Cinchona calisaya trees, a typical element of the intermediate altitudes of the Bolivian Yungas. We determine the relative effects of edaphic properties, climate, and geography in regulating fungal community assembly. We show that α-diversity for these fungal communities was similar to temperate and arid ecosystems, averaging 90.1 operational taxonomic units (OTUs) per sample, with reads predominantly assigned to the Ascomycota phylum and with a saprotrophic lifestyle. ß-diversity was calculated as the distance-decay rate, and in contrast to α-diversity, was exceptionally high with a rate of −0.407. Soil properties (pH and P) principally regulated fungal community assembly in an analogous manner to temperate environments, with pH and phosphorus explaining 7.8 and 7.2% of community variation respectively. Surprisingly, altitude does not influence community formation, and there is limited evidence that climate (precipitation and temperature) play a role. Our results suggest that sampling should be performed over a wide geographical and environmental range in order to capture the full root-associated fungal diversity in subtropical regions. This study sheds further light on the diversity and distribution of the world's “hidden biodiversity.”

Community structure and functional group of root‐associated Fungi of Pinus sylvestris var. mongolica across stand ages in the Mu Us Desert

“…They play important roles in ecosystem functions, by participating in a series of crucial ecological processes in terrestrial ecosystems (Fisher et al, 2012;Wehner et al, 2014). In early studies, scholars mainly focused on RAF diversity and community composition in specific habitats or host plants (Barnes, Maldonado, Froslev, Antonelli, & Ronsted, 2016a;David, Seabloom, & May, 2016). The identification of fungal functional groups was then explored, based on RAF community taxonomy, to accurately reflect the growth, development, and fitness of host plants (Nguyen et al, 2016).…”

Tree communities and soil properties influence fungal community assembly in neotropical forests

“…Macrofungi can be sensitive to decay stage of the litter (Gibertoni et al, ), which can be highly heterogeneous at a small scale and depend on leaf chemistry (Hättenschwiler, Aeschlimann, Coûteaux, Roy, & Bonal, ). As soil microfungi communities in neotropical forests are hyperdiverse and exhibit a high percentage of uncharacterized fungi (Barnes et al, ), we surely missed a great part of this diversity by focusing only on fruiting bodies. Therefore, as a first approach, barcoding herbarium collections and high‐throughput inventories of fresh fruiting bodies are necessary to document fungal diversity (Barnes et al, ; Halme, Heilmann‐Clausen, Rämä, Kosonen, & Kunttu, ), particularly in neotropical forests where large territories remain unexplored (Blackwell & Vega, ; Truong et al, ).…”

“…As soil microfungi communities in neotropical forests are hyperdiverse and exhibit a high percentage of uncharacterized fungi (Barnes et al, ), we surely missed a great part of this diversity by focusing only on fruiting bodies. Therefore, as a first approach, barcoding herbarium collections and high‐throughput inventories of fresh fruiting bodies are necessary to document fungal diversity (Barnes et al, ; Halme, Heilmann‐Clausen, Rämä, Kosonen, & Kunttu, ), particularly in neotropical forests where large territories remain unexplored (Blackwell & Vega, ; Truong et al, ). By sampling macrofungi in remote areas of French Guiana, we also unraveled factors shaping Basidiomycetes distribution in this region.…”

“…From this perspective, French Guiana largely remains an uncharted territory, and existing collections of fungi have been confined to few coastal localities. Both taxonomists and ecologists have claimed that there is an urgent need to systematically collect and document fungal specimens from undersampled areas to fill the gaps of knowledge in a region where fungal diversity may be much higher than actually known (Barnes, Maldonado, Frøslev, Antonelli, & Rønsted, ; Roy et al, ; Truong et al, ). This sampling effort could last for years, but could be guided by community‐level analysis, for example, to detect favorable habitats (Roy et al, ) or sampling periods (Braga‐Neto, Luizão, Magnusson, Zuquim, & Castilho, ) that may not appear at a first glance.…”

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“…Additionally, soil properties, in particular phosphorus, can affect the taxonomic composition of microbial communities (Buckley and Schmidt, 2001;Faoro et al, 2010;Navarrete et al, 2013). In addition, pH is known to shape microbial diversity (e.g., Osborne et al, 2011;Kuramae et al, 2012;Bates et al, 2013;Barnes et al, 2016). Different soil layers may show different patterns of biodiversity (Hinsinger et al, 2009).…”