Composición de las comunidades de hongos micorrícicos arbusculares en diferentes usos de suelo en el Caldenal, Argentina

Abstract

Arbuscular mycorrhizal fungi (AMF) are mutualistic symbionts associated with most terrestrial plants. HMA communities vary in composition and life histories and are affected by land use and management. The caldén forests (Prosopis caldenia Burkart) in the province of San Luis have suffered a considerable reduction in their area. Currently, its relics are part of a landscape made up of forests and lands cultivated with Medicago sativa L. (alfalfa) and Eragrostis curvula (Schrad.) Nees (weeping lovegrass), key forage species for livestock production in the region. Considering the ecological and economic importance that these land uses have for the region, the objective of this work was to analyze whether the diversity of AMF is affected by the change in land use from caldén forest to alfalfa or weeping lovegrass plots and whether there are indicator species for each use. Four plots of permanent forest were established, 4 of alfalfa and 4 of weeping lovegrass. Soil samples were taken from each plot, the physicochemical characteristics were determined and the AMF spores were extracted. The composition of the spore communities was different in each land use. The AMF morphospecies richness did not showed differences between forest and alfalfa but show differences with weeping lovegrass. Total abundance, spore abundance of ruderal and stress-tolerant species were significantly higher in alfalfa. In addition, 2 indicator species were identified in alfalfa, 1 in forests, and 2 in weeping love grass. This study provides evidence suggesting that land-use change in Caldenal significantly alters the composition of AMF spore communities and may have a negative effect on this endemic forest.