Disturbance and land use effect on functional diversity of the arbuscular mycorrhizal fungi

The arbuscular mycorrhizal fungal diversity in Mexico has not been intensively studied. Although some studies have reported the presence of 29 % of the reported species in the world, the knowledge regarding their functional diversity is poor. The aim of this study was to evaluate the impact of the disturbance on arbuscular mycorrhizal fungi (AMF) functional diversity. Three sites at the Biosphere Reserve Los Tuxtlas in the state of Veracruz were selected for this study, according to the disturbance gradient and the land use: Lpez Mateos (LM), San Fernando (SF), and Venustiano Carranza (VC) (with low, medium and high disturbance, respectively). The land use in each site includes milpa and pasture. High percentages of root colonization, spore abundance and spore viability were found on LM soils. Additionally, 100 % of the pasture soils have a high mycorrhizal infective potential (MIP). In addition, the fungi consortiums coming from that site promote the highest mycorrhizal growth response (MGR), with increases ranging from 74.1 to 194.6 % over the control treatment. SF soils had high percentages of root colonization and spore viability, whereas only 20 % of these soils had a high MIP, and their MGR promoted increases ranged from 14.6 to 120.4 % over the control. Soils from VC had the lowest percentages of root colonization and spore viability. Only 10 % of the soils had high MIP, and their MGR was not better than the control. These results indicate that the soil disturbance or use changes negatively affect the functionality of AMF.