Abstract

ESCUTIA-LARA, Yazmín  and  LINDIG-CISNEROS, Roberto. Dynamics of Phragmites autralis and Schoenoplectus americanus in response to the addition of phosphorus and nitrogen in experimental wetlands. Bot. sci [online]. 2012, vol.90, n.4, pp.459-467. ISSN 2007-4476.

Invasive species, such as Phragmites australis, are major competitors for native species, however, very little is known about the mechanisms of invasion. In this study the interaction between P. australis with a native species, Schoenoplectus ame-ricanus, was evaluated through a split-plot experiment with addition of nutrients (nitrogen and phosphorus). For P. australis statistically significant differences (P < 0.05) were found among treatments for height, number of stems, aboveground biomass and rhizomes, while for S. americanus, statistically significant differences (P < 0.05) were found for maximum height, average height of stems and number of stems, percentage of coverage and aboveground biomass. The increase in nutrients did not allowed the displacement of S. americanus by P. australis. This result suggest that under natural conditions S. americanus could be able to compete for nutrients and not be displaced by P. australis, as longs as no disturbance occurs, because in this study the native species canopy was not altered before introducing P. australis. Our results suggest that intraspecific competition is stronger than interspecific in the absence of disturbance.

Keywords : competence; composition; disturbance; diversity; ecological restoration; nutriments.