Influence of Yacyretá dam on trees distribution in the Paraná floodplain

摘要: Abstract Numerous contributions indicate that the distribution of trees in floodplains is determined by hydrological dynamics and some plants are more tolerant than others to flood periods, however very little scientific information allows link regulation pulse regime dams with impacts they produce on river vegetation. We assume frequency curves floodplain a synthetic representation niche each species respect macrofactor conditions their distribution. compared two surveys vegetation: one before reservoir -in 1980-, another 2014, thirty-fourth years after building Yacyreta, same places, method 175 km stretch Upper Parana floodplain, downstream Yacyreta dam. Using as an indicator densities based dominant its relationship we establish response forest pulsing both periods. Our results during 34 years there were significant changes occurrence at site between sites. found selected show operation reservoir, despite which only statistically 40% surveyed. The our study provide criterion for analysis forests large rivers.