Exploring the impact of land use change and seasonality on arbuscular mycorrhizal fungi communities in the Caldén District, Argentina

ONTIVERO R. E.; RISIO, L. V.; IRIARTE, H. J.; LUGO M. A.

Leticia

Simposio; III International Symposium of the Mycorrhizal Symbiosis in South America.; 2023

Instituto SINCHI-Amazonas, Colombia, Universidad Nacional de Colombia, South American Mycorrhizal Research Network

Arbuscular mycorrhizal fungi (AMF) are mutualistic symbionts that form biotrophic associations with the majority of terrestrial plants. In the province of San Luis (Argentina), the native endemic forests of Caldén (Neltuma caldenia) have experienced a significant reduction in their original extent due to the expansion of agricultural and livestock activities. This study aimed to investigate the diversity of AMF communities in various plots located in forests dominated by native vegetation, particularly Neltuma caldenia Forest (here after Forest), as well as in Weeping Grass (Eragrostis curvula) pastures, Alfalfa (Medicago sativa), and Soybean (Glycine max) monocultures. Soil samples were collected from each plot during two seasons (winter and summer), and the AMF diversity parameters, along with the physical and chemical characteristics of the soil, were analyzed. The results revealed that the Forest plots exhibited the highest AMF diversity, followed by Alfalfa, Weeping Grass, and Soybean monoculture. The diversity and abundance of AMF displayed contrasting variations among the different plots. Seasonality had differential influences on the different plots (land uses). During the summer season, the Forest and Alfalfa plots displayed the highest average richness, signifying a greater AMF diversity. In contrast, the Soybean plots exhibited the highest average abundance of AMF spores during the same season, indicating a higher population density. These variations are likely attributed to the disturbances associated with the replacement of natural vegetation and the intensity of agricultural and livestock activities. It has been demonstrated that agricultural and livestock activities can differentially influence the dynamics of native AMF communities.