WETLAND DEPENDENCY DRIVES TEMPORAL TURNOVER OF BIRD SPECIES BETWEEN HIGH AND LOW WATER YEARS IN FLOODPLAIN WETLANDS OF THE PARANÁ RIVER

LORENZÓN, R.E.; RONCHI-VIRGOLINI, A. L.; BLAKE, J.

ECOHYDROLOGY

JOHN WILEY & SONS INC

Lugar: New York; Año: 2019 vol. e217

1936-0584

Temporal turnover of species between predominantly aquatic and terrestrialphases of floodplains, a process that helps maintain the high bird diversity of riverfloodplain systems, could be driven by dependency of species on wetlands. To assess this, we compared the bird assemblages of river-floodplain systems at 60 sites along the Paraná River during the non-breeding seasons of 2011, when water levels were predominantly high (high-water year), and 2012, when levels were predominantly much lower (low-water year). Birds were sampled by point counts repeated four times during each year at each site. We tested whether temporal patterns differed between wetland-dependent and non-wetlanddependent birds because these groups show positive and negative relationships, respectively, with water-level increases. Species composition varied between years. Ten of the 14 species associated with high water levels in 2011 were waterbirds and 11 of the 14 species associated with lower water levels (2012) were non-wetland species. Species richness and abundance per site of waterbirds and abundance of wetland species were higher during the high-water year than in the low-water year. Species richness, abundance and diversity per site of non-wetland birds were, on the other hand, higher during the lowwater year than in the high-water year. Species turnover between predominantly high- andlow-water periods did not respond to shorter-term water-level fluctuations within each year. In conclusion, our results show that degree of wetland dependence drives bird species turnover as a function of water-level fluctuations, showing the importance of hydrological variability for bird conservation in river-floodplain systems.