Poster #13

Arbuscular mycorrhizal fungi and dark septate endophytes in Brazilian semiarid forests and savannas along a water-stress gradient
NCF XIMENES, AMB DE BRITO, KHP GOMES, IL DA CRUZ, A ABRAHÃO
Departamento de Biologia, Universidade Federal do Ceará, Avenida Mister Hull, S/N - Campus do PICI, Fortaleza - CE, Brasil, 60440-900

Plant-associated fungi, such as arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) can increase plant tolerance to drought stress, and extend nutrient acquisition beyond the rhizosphere. These associations are especially important in semiarid zones with irregular rainy seasons, where the short favorable window of opportunity for resource acquisition limits plant growth. We evaluated the root fungal colonization of 60 species and soil spore abundance in four sites along a water-stress gradient in NE Brazil, where the Thorntwaite aridity index varied from 27 (driest) to 80% (most humid). We observed greater AMF colonization and spore abundance at the driest sites. Within the second driest site, we also evaluated DSE colonization, and found that all the 16 species assessed were colonized by DSE. The Brazilian semiarid zone is prone to desertification, since tree overharvest and poor soil management has led to strong soil erosion (sometimes >1 m). Recovering the native plant cover with their associated AMF and DSEs will help mitigate climate change and prevent further desertification.