Sapwood mycobiome varies across host, plant compartment and environments in Nothofagus forests from Northern Patagonia

Abstract

Global forests are increasingly being threatened by altered climatic conditions and increased attacks by pests and pathogens. The complex ecological interactions among pathogens, microbial communities, tree hosts and the environment are important drivers of forest dynamics. Little is known about the ecology of forest pathology and related microbial communities in temperate forests of the southern hemisphere. In this study, we used next‐generation sequencing to characterize sapwood‐inhabiting fungal communities in North Patagonian Nothofagus forests and assessed patterns of diversity of taxa and ecological guilds across climatic, site and host variables (health condition and compartment) as a contribution to Nothofagus autecology. The diversity patterns inferred through the metabarcoding analysis were similar to those obtained through culture‐dependent approaches. However, we detected additional heterogeneity and greater richness with culture‐free methods. Host species was the strongest driver of fungal community structure and composition, while host health status was the weakest. The relative impacts of site, season, plant compartment and health status were different for each tree species; these differences can be interpreted as a matter of water availability. For Nothofagus dombeyi, which is distributed across a wide range of climatic conditions, site was the strongest driver of community composition. The microbiome of N. pumilio varied more with season and temperature, a relevant factor for forest conservation in the present climate change scenario. Both species carry a number of potential fungal pathogens in their sapwood, whether they exhibit symptoms or not. Our results provide insight into the diversity of fungi associated with the complex pathobiome of the dominant Nothofagus species in southern South America.

Exploring Rubiaceae fungal endophytes across contrasting tropical forests, tree tissues, and developmental stages

“…Leaves harbored more robust and rich assemblages than sapwood, although the latter is considered rich in organic nutrients and is a target of many different organisms (63). We observed little overlap between foliar and sapwood endophytes, suggesting spatial heterogeneity across plant compartments (64–66).…”

Diversity, Community Structure, and Antagonism of Endophytic Fungi from Asymptomatic and Symptomatic Mongolian Pine Trees

“…Differing findings in Scots pine ( P. sylvestris ) were reported by Blumenstein et al [ 6 ], suggesting that diversity indices did not exhibit statistical differences between disease classes, indicating a similar mycobiome in Scots pine of different health classes at the already diseased (Diplodia tip blight) forest site. It appears that host species and tree genotype may influence the composition and community structure of the tree mycobiome [ 44 , 45 ].…”

Insights into Ecological & Evolutionary Processes via community metabarcoding

“…To understand these relationships, Molina et al. (2022) tested the role of climate, site, and host variables in structuring sapwood‐inhabiting fungal communities across a gradient of climatic, seasonal and site factors in the North Patagonian Nothofagus forests. The results supported their hypothesis that host identity and site were the major drivers of fungal community structure.…”