Effects of flooding duration on species richness, floristic composition and forest structure in river margin habitat in Amazonian blackwater floodplain forests: implications for future design of protected areas

摘要: Rivers in central Amazonia experience annual water-level fluctuations of up to 14 m, flooding vast areas adjacent forest for periods ranging from a few 270 days per year. At different sites, variation the duration and type results mosaic habitats that includes lakes, grasslands, forests, streams. To study effects flood on plant species richness floristic composition, two river margin sites were surveyed rivers Jau Taruma-Mirim. Both are seasonally flooded by blackwaters, plots made at topographic levels (lower, middle upper slopes). All woody plants with DBH > 5cm inventoried five 10 × 40 m each three levels, which varied length mean water level. Plant did not vary significantly between but composition substantially. both exhibited distinctive distribution patterns respect site. Differences dominant probably relate ability withstand seasonal flooding, although other edaphic factors associated may also be important, especially less-dominant, locally rare, habitat generalist species. Species overlap among was highly variable 15% 43%. Knowledge about complex pattern distributions is important preservation diverse flora blackwater forests creation future conservation management plans design protected this ecosystem will maintain biodiversity.