Spellmeier, Jaqueline  Périco, Eduardo  Haetinger, Claus  Freitas, Elisete Maria  Morás,  Ana Paula de Borba  <br/><br/>
Effect of Grazing on the Plant Community of a Southern Brazilian Swamp 

<br/><br/> Publicação on-line; 40 ref.; 1 table; 4 illus.; Summary (En) 
<br/><br/> <br/><br/>ABSTRACT<br/><br/>Swamps have high biological diversity and are the largest producers of biomass. However, such<br/>ecosystems are threatened by human activities. This study analyzes the plant community structure<br/>of two swamp sites, with and without grazing. A total of 200 sample units with 0.25 m2 were<br/>distributed every 13 m to determine diversity, the Importance Value Index (IVI), and coverage.<br/>Fifty species and 18 families were recorded. Luziola peruviana Juss. ex. JF Gmel had the highest<br/>IVI, accounting for 62.57% of the relative coverage in cattle-influenced sites. In the portions<br/>without cattle, Commelina diffusa Burm.f. had the highest IVI (24.33). The Shannon and Pielou<br/>indexes were 2.18 nats.ind.–1 and 0.56, respectively, decreasing to 1.62 nats.ind.–1 and 0.47 in<br/>grazing sites. There was less richness in the cattle grazing area, with a single species accounting<br/>for a high percentage of coverage, indicating the possible role of grazing on the plant community<br/>structure.<br/><br/>Keywords: diversity indexes, phytosociology, wetlands. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>PÂNTANO<br/>PASTEJO<br/>ECOLOGIA<br/>VEGETAÇÃO