Acta Limnologica Brasiliensia
versão On-line ISSN 2179-975X
ROLON, Ana Silvia; HOMEM, Henrique Flores e MALTCHIK, Leonardo. Aquatic macrophytes in natural and managed wetlands of Rio Grande do Sul State, Southern Brazil. Acta Limnol. Bras. (Online) [online]. 2010, vol.22, n.2, pp. 133-146. ISSN 2179-975X. http://dx.doi.org/10.4322/actalb.02202003.
AIM: This study gathers the main results obtained from studies regarding dynamic of aquatic macrophyte community in natural and managed wetlands of Southern Brazil. We analyzed the aquatic macrophytes diversity in wetlands of Southern Brazil, the environmental factors that determine the structure of the aquatic macrophyte community in fragmented wetlands, the effects of floods on the dynamics of macrophytes, and the contributions to the rice field for the conservation of aquatic macrophytes; METHODS: The information was obtained from several researches carried in several spatial scales and different wetlands types over the last 10 years in Southern Brazil; RESULTS: The studies have reported the occurrence of approximately 250 species of aquatic macrophytes. Wetland area, habitat diversity, altitude and hydroperiod were determinant for macrophyte richness and composition in wetlands of Southern Brazil. Furthermore, flood events, long or short-term ones, are strongly associated to the structure of the aquatic macrophyte community. The rice field systems of Southern Brazil (crops and irrigation channel) shelter a representative number of species of macrophyte found at natural wetlands in this region. The agricultural practices adopted over rice cultivation cycle in the rice fields have influenced the macrophyte richness and biomass. The different hydrological management practices adopted after the harvesting period (presence or lack of water surface) did not influence the macrophyte richness and biomass, however it influenced the species composition; CONCLUSIONS: The increasing process of wetland degradation (e.g. fragmentation, flood control and rice field expansion) presents a threat to the conservation aquatic macrophyte species.
Palavras-chave : aquatic plant; diversity; conservation; Neotropical region.