MYCORRHIZAL FUNGI IN CHACO FOREST FRAGMENTS: DIVERSITY AND EFFECTS ON NATIVE AND EXOTIC PLANT SPECIES

GRILLI G.; URCELAY CARLOS; GALETTO LEONARDO

Jäneda

Conferencia; Departmental conference dedicated to the 120th anniversary of Theodor Lippmaa; 2012

Global changes have been related to alterations on the biodiversity of ecosystems in the last decades. Among these global changes, forest fragmentation process promotes modifications to plant community structure and functioning. In turn, these changes in plant community are related to biological invasions, another threat to biodiversity. However, whether forest fragmentation is related to soil properties and organisms (i.e., mycorrhizal fungi), in a direct way (whit reduction in forest fragment size) or indirect (through changes in vegetation), and whether this variation in soil fungi affects vegetative and reproductive plant development remains largely unknown. This study was performed in a fragmented landscape at Córdoba Province in Central Argentina. Studied species were two abundant annual ruderal Euphorbia herbs (Euphorbia acerensis and Euphorbia dentata, native and exotic, respectively). Forest fragmentation was negatively related to mycorrhizal root colonization and to Arbuscular Mycorrhizal Fungi (AMF) diversity, and positively related to soil nutrients concentration. Also, plant development in ruderal species (i.e., native and exotic) was negatively related to mycorrhizal colonization while forest fragment size increases. AMF negatively affect vegetative and reproductive development in native hosts and inconsistently affect exotic host development at the greenhouse. Forest fragmentation could be affecting soil nutrient availability, which in turn might be affecting plant-fungi interaction and AMF community composition. Therefore, this could lead changes on vegetation due to AMF might be affecting traits host directly related to ecological processes (i.e., competition, pollination, etc.). Moreover, differential effects between native and exotic hosts might be pointing out the importance of mycorrhizal fungi on biological invasions at fragmented landscape.