Aquatic macrophytes in natural and managed wetlands of Rio Grande do Sul State, Southern Brazil

Abstract

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.

Brazilian wetlands: their definition, delineation, and classification for research, sustainable management, and protection

“…The original vegetation cover of this biome has been reduced to 11.7% by Table 2. Taxonomic diversity of trees and herbaceous plants in the Amazon River floodplain (várzea) (Junk and Piedade, 1993;Wittmann et al, 2010;Wittmann, 2013), the Pantanal (Pott and Pott, 2000;Junk et al, 2006), and the freshwater wetlands of southern Brazil (Rio Grande do Sul) (Rolon et al, 2010) Amazon deforestation (Ribeiro et al, 2009). Wittmann (2012) differentiated inland wetlands of the Atlantic forest in riparian forests along streams and interfluvial montane fens, bogs, and hygrophile forests and provided a synopsis of the existing literature on forest inventories and the most common wetland tree species.…”

“…Southern freshwater wetlands belong mostly to the subclass of 'swampy wetlands covered by herbaceous plants', which occupy relatively small areas. An inventory of 260 wetlands of 0.15-10 ha revealed a low number of flood-tolerant trees and a highly diversified herbaceous aquatic and palustric flora ( Table 2, Rolon et al, 2010).…”

Morphometry and retention time as forcing functions to establishment and maintenance of aquatic macrophytes in a tropical reservoir

“…All aquatic macrophytes recorded in Ourinhos Reservoir are common in Neotropical reservoirs and lakes (Vilarrubia and Cova, 1993;Bini et al, 1999Bini et al, , 2005Neiff, 2001;Nahlik and Mitsch, 2006;Neiff et al, 2008;Martins et al, 2008;Bianchini Junior et al, 2010;Henry-Silva et al, 2010;Piedade et al, 2010;Rolon et al, 2010;Alves Ferreira et al, 2011). In the Paranapanema watershed, these species were also usually recorded in the following reservoirs: Rosana, Salto Grande, Chavantes, Piraju and Jurumirim (Henry and Nogueira, 1999;Casatti et al, 2003;Martins et al, 2008;Neves, 2008;Bianchini Junior and Cunha-Santino, 2014).…”

“…Neotropical aquatic ecosystems usually support several species of aquatic macrophytes (Neiff et al, 2008;Rolon et al, 2010;Piedade et al, 2010). The metabolic response of these organisms to abiotic factors combined with biological interactions (e.g., competition for light, herbivory, allelopathy) determine the basis of the community diversity and abundance (Lacoul and Freedman, 2006;Bornette and Puijalon, 2009).…”

Connectivity among Wetlands of EPA of Banhado Grande, RS

“…According to Rolon, Homem and Maltchik (2010) are ecosystems that remain flooded for a long enough time, allowing the establishment of soggy soils and aquatic plants.…”