Small-scale variation in a pristine montane cloud forest: evidence on high soil fungal diversity and biogeochemical heterogeneity

Abstract

Montane cloud forests are fragile biodiversity hotspots. To attain their conservation, disentangling diversity patterns at all levels of ecosystem organization is mandatory. Biotic communities are regularly structured by environmental factors even at small spatial scales. However, studies at this scale have received less attention with respect to larger macroscale explorations, hampering the robust view of ecosystem functioning. In this sense, fungal small-scale processes remain poorly understood in montane cloud forests, despite their relevance. Herein, we analyzed soil fungal diversity and ecological patterns at the small-scale (within a 10 m triangular transect) in a pristine montane cloud forest of Mexico, using ITS rRNA gene amplicon Illumina sequencing and biogeochemical profiling. We detected a taxonomically and functionally diverse fungal community, dominated by few taxa and a large majority of rare species (81%). Undefined saprotrophs represented the most abundant trophic guild. Moreover, soil biogeochemical data showed an environmentally heterogeneous setting with patchy clustering, where enzymatic activities suggest distinctive small-scale soil patterns. Our results revealed that in this system, deterministic processes largely drive the assemblage of fungal communities at the small-scale, through multifactorial environmental filtering.

Colombian coffee (Coffea arabica L.) plantations: a taxonomic and functional survey of soil fungi

“…Saprotrophs were among the abundant trophic modes with a high number of species with low prevalence (i.e., <25%) and low abundance per site (i.e., <10%) that were grouped as "other. " Dominance of saprotroph was reported earlier in tropical forests and coffee plantations suggesting that saprotrophs are key players in nutrient cycling (Looby and Treseder, 2018;Velez et al, 2021). Among the surveyed farms, we found that Ascomycotan Arachnotheca glomerata (Onygenaceae) and Basidiomycotan Geastrum spp.…”

“…This pathogen is not a menace in productive plantations and has rarely been reported in coffee plantations (Duong et al, 2020;Lu et al, 2022b). Apiotrichum and Fusarium were among the dominant genera, and this finding was previously reported in coffee plantations and montane forest (Arias and Abarca, 2014;Velez et al, 2021). Apiotrichum and Fusarium have been described as devastating pests affecting coffee production in Africa, where they usually infect mature trees and affect S2).…”

“…Mortierellomycota is frequently represented in investigations of soil fungi. It has been identified among generalist fungi of cropping systems (Toju et al, 2018;Grzadziel and Gałazka, 2019;Wang et al, 2021), and among the most characteristic micro-fungal species in montane cloud forest (Velez et al, 2021). Mortierellomycota became highly dominant in soils after the addition of organic amendments (Li et al, 2018(Li et al, , 2021, and high soil P availability negatively affected Mortierellomycota abundance (Detheridge et al, 2016;Orrù et al, 2021).…”

Trichoderma Diversity in Mexico: A Systematic Review and Meta-Analysis

“…However, only Trichoderma ceraceum was reported in this ecosystem, according to our review [103]. Velez et al (2021) [104] identified six morphotypes of Trichoderma in Mexican mountain cloud forests, but they did not identify these strains at the species level.…”

Soil microbes support Janzen’s mountain passes hypothesis: The role of local-scale climate variability along a tropical montane gradient

“…We expected that the local-scale soil climatic variables would play more critical roles than soil chemistry and vegetation in shaping bacterial and fungal diversity patterns and composition along the tropical elevational gradient, thereby supporting the Janzen’s hypothesis ( Frindte et al, 2019 ; Ma et al, 2022 ). Likewise, we expected that soil microbial communities would respond to the unique climate in cloud forests and hold a unique pattern in diversity and composition compared with other forests in the mountain ( Zimmermann et al, 2009 ; Velez et al, 2021 ).…”