The effect of gypsum mining on arbuscular mycorrhizal fungi (AMF) was evaluated. Soil samples (10/area) were collected in four areas of a mine: native "caatinga" (CN); mine surroundings (AM); waste deposit (R) and interface between waste deposit and degraded caatinga (IN), in two periods, raining (December/2003) and dry (September/2004). Fourty two phanerogam species were registered: 25 at CN, 14 at AM, 10 at IN, and 5 at R. The CN presented higher number of plant species, spores and infectives propagules (most probable number-MPN) of AMF. Number of spores and root colonization differed between the periods. Higher sporulation occurred in the raining season, MPN of propagules and colonization were higher in the dry season. Positive correlation occurred between MPN and spores in both periods. In the raining season, MPN was negatively correlated with colonization. That was higher in the AM and R areas. The mining activity decreased plant diversity, MPN of propagules and amount of AMF spores in relation to the native caatinga.
arbuscular mycorrhizae fungi; infective propagules; root colonization
