Arbuscular mycorrhizal fungi and bacterial communities across selective logging, low-flooded forest and conserved Mayan Forest

Abstract

Promoting biological conservation requires expanding our understanding of species distributions, biodiversity, and their responses to anthropogenic impacts, including unexplored environments that could serve as biological refugia. In the Yucatán Peninsula, Mexico, forestry relies on selective logging practiced under sustainable communal management that is biologically interconnected with seasonally flooded forests. Despite being an important environment for specialized flora, fauna, and carbon storage, soil biodiversity remains insufficiently understood. This study aimed to evaluate and compare the diversity and community composition of bacterial and arbuscular mycorrhizal fungi (AMF) across contrasting environments within a vegetation gradient: selectively logged, (six years post-harvest), conserved, and seasonally flooded low-stature forests by integrating environmental DNA analyses (16S and 18S rRNA genes for bacteria and AMF, respectively) with morphological characterization of AMF glomerospores. AMF community composition (environmental DNA sequences) significantly differed between selective logging and low-flooded forests. Bacterial diversity was similar across sites, but richness was higher in the selective logging. Conserved forest had higher Actinobacteria abundance, while low-flooded forest had more Verrucomicrobia. Additionally, selective logging showed higher Chloroflexi diversity. Despite these differences, bacterial and glomerospores community structures were similar across sites. Redundancy analysis revealed no significant differences between soil chemistry and microbial community structure. Our findings suggest that selective logging maintains soil microbial diversity. Furthermore, seasonally flooded forests harbor distinct AMF assemblages, potentially including undescribed taxa, highlighting their value as unique reservoirs of belowground biodiversity. These microbial patterns may influence key soil functions, such as nutrient cycling and soil carbon dynamics.