Functional land-use change effects on soil fungal communities in Chilean temperate rainforests

Abstract

By reducing soil organic matter and litter input, land-use changes are predicted to decrease total soil fungal diversity, but at functional levels this have been poorly studied. It is expected, though, that increasing disturbance decreases saprotrophic and mycorrhizal fungi biodiversity. This study aimed to determine the effects of land-use changes on the phylogenetic and functional diversity of soil fungi in the Southern Andes. We assessed the fungal communities of Andosol topsoil at 1 cm and 10 cm soil depth. The soil samples were obtained from a gradient of anthropogenic disturbance; specifically, plots were located within pristine forest, overstory-managed, and clearcut conditions. We used a cultivation-independent molecular barcoding approach to assess fungal diversity and identify 1,173 OTUs from which 401 were assigned to a functional guild. While we found higher phylogenetic richness in clear-cut conditions, these soils had higher relative abundances of plant pathogen fungi and lower relative abundances of saprotrophic and ectomycorrhizal fungi compared to the other treatments. The opposite pattern was found in pristine forest. Thus, fungal species richness itself does not seem to reflect ecosystem health. Interestingly though, the lower phylogenetic diversity found in pristine forest was compensated by a higher diversity of fungi involved in nutrient cycling.

The soil fungal community of native woodland in Andean Patagonian forest: A case study considering experimental forest management and seasonal effects

“…The most abundant classes in both seasons were the Agaricomycetes, followed by Leotiomycetes, Sordariomycetes, and Tremellomycetes. These results could partially overlap with the work of Marín et al (2017) and Duo Saito et al (2018). Marín et al (2017) found that in general Agaricomycetes, Dothideomycetes, and Sordariomycetes were the most abundant soil fungus classes in Nothofagus forests of Chile.…”

“…These results could partially overlap with the work of Marín et al (2017) and Duo Saito et al (2018). Marín et al (2017) found that in general Agaricomycetes, Dothideomycetes, and Sordariomycetes were the most abundant soil fungus classes in Nothofagus forests of Chile. Furthermore, Duo Saito et al (2018) found that in naked soil near glaciers the Leotiomycetes were the most common taxon, followed by Sordariomycetes, Dothideomycetes, and Eurotiomycetes.…”

“…The most abundant orders in both seasons were Agaricales (Agricomycetes) and Helotiales (Leotiomycetes), followed by Mortierellales (Mortierellomycetes) and Filobasidiales (Tremellomycetes). Agaricales, Helotiales and Mortierellales presented high percentages of abundances in other works (Lim et al, 2010;Sterkenburg et al, 2015, Zhang et al, 2016Truong et al, 2019), and Agaricales have high diversity in the Patagonian Nothofagus forests when compared with European Fagus forests (Marín et al, 2017;Godoy and Marín, 2019). Chemical properties of the soil, such as gravimetric humidity, EC, C, N, and available P, were modelers of the fungal community at different taxonomic levels (Fig.…”

“…regions to that studied in this work (Marín et al, 2017). In addition, yeasts from these groups have also been cited in soil (Mestre et al, 2014), in aquatic environments (Libkind, 2006), and in N. nervosa fruits (Fernández et al, 2012) in the region.…”

“…plant pathogens such as Ilyonectria) and other symbionts, related with high values of C and N. In summer there was an increase in the sequences of saprotrophs and ectomycorrhizal fungi, which could be related to the increase in sequences of Cortinarius, one of the most abundant genera in Nothofagaceae forest (Hewitt et al, 2018;Truong et al, 2019). Marín et al (2017) saw an inverse relationship between pathotrophs and symbiotrophs, related to the use of land; in plots with intense use (=total removal of vegetation) pathogens were more abundant, and the pristine, managed (=partial removal of vegetation) plots had higher mycorrhizal fungal abundance. Tedersoo et al (2014) recorded the effect of pH and the plant community on ectomycorrhizal fungi, and the effect of the distance from the equator and soil C/N ratio for pathogens, and suggested that the richness of fungi and functional groups is unrelated to plant diversity, with the exception of ectomycorrhizal fungi, since plant-soil feedbacks does not influence the diversity of soil fungi on a global scale.…”