Can we know the hydrological signature of the Paraná River floodplain vegetation, using the PULSE function?

CASCO, S.; NEIFF, J.J.

Cuiabá, Brasil

Congreso; 8th. International Wetland Conference of INTECOL Internat. Ecol. Soc).; 2008

INTECOL (Internat. Ecology Society)

Can we know the hydrological signature of the Paraná River floodplain vegetation, using the PULSE function? S. L. Casco & J. J. Neiff SUMMARY It is known and accepted that the organisms that live in floodplains are conditioned mainly for the hydrologic regime of the river. However, we have not found results that relate quantitatively the hydrological conditions of each floodplain’s topographic level with the occurrence of plants. Our hypothesis that each tree will be found in those places where the more appropriate conditions of fitras are found to fulfill its germination, growth, flowering and fructification. Inside a 50 Km long and 8.5 Km wide tract in the Paraná River (45 Km downstream of it’s junction with the Paraguay River), within the Ramsar Site Chaco, we selected 1012 sampling points. During the extraordinary flood of 1997-98 (ENSO event), we registered the topographical position of each place and also the plants that grew there. Later on, in a figure of coordinates we placed the topographical position of the occurrence of the species on the X- and Y-axes. This way we obtained the curve of distribution of each species for each topographical level and pulse regime. The species were distributed in a wide range, reaching their maximum occurrence (262) at 49.19 m.a.s.l., only 5% of the species grow in the extremes of the topographical gradient (among 44.2 m.a.s.l. and 51.8 m.a.s.l.). We postulate that each tree species and, possibly each state of growth of that species, has a hydrologic signature that can be quantified with the software PULSE.