Stoichiometric constraints in plant species invasion in Patagonia temporary wetland

CUASSOLO, FLORENCIA; ESTEBAN, BALSEIRO; BEATRIZ, MODENUTTI

San Carlos de Bariloche

Congreso; VI Southern Connection Congress; 2010

UNCOMAHUE- INTA- CONICET

During the dry season, temporary or semi temporary wetlands are often invaded by exotic or native terrestrial plants, and when flooded, plant tissues would contribute differently to the elemental composition of the aquatic environment. Potentilla anserina is an exotic species in Patagonia and frequently invade potentially flooded areas. We aimed to analyze stoichiometric constraints of macrophytes species that colonize wetlands, examining elemental relationship (C:N:P) of vegetal tissue (shoots and roots) of three different plant species. Our results showed that C:N did not varied significantly between shoots and roots of each species. On the contrary, C:P was observed to be lower in the roots indicating a higher P allocation. In particular, P. anserina exhibited the lowest root C:P ratios (half that of the native macrophytes). The elemental composition of the vegetal tissue could depend on the presence of micorrhyzal fungi. While no infection was recorded in Carex aematorrhyncha, infection was dominated by arbuscular micorrhyzal in P. anserina and by dark sepatate endophyte in Eleocharis pachycarpa. The differences in micorrhyzal infection and elemental composition would contribute to the success of P. anserina as invader.