Effects of artificial reservoirs on evapotranspiration and bird´s fauna

Abstract

San Luis is an Argentine province whose semi-arid climate led to the construction of artificial water bodies throughout its territory, generating concern about the environmental and hydrological effects, on a local and regional scale, that these reservoirs could cause. In this sense, evapotranspiration (ET), the main water loss in any ecosystem, represents an important part of the water balance. Likewise, bird communities respond to the presence of new water mirrors, where the humidity represents one of the most relevant variables determining the vegetation composition and food availability. For this reason, ET was related to bird richness and abundance in this study, using ET as a surrogate of humidity. Thus, based on remotely sensed ET data, the time-space dynamics of the ET were determined before and after the construction of the reservoirs, obtaining space thresholds of their impact. In addition, the bird’s composition, and abundance were related to water mirrors here and correlated with the ET and vegetation dynamics. Results indicate an increase in the ET means values up to 500 m from the reservoir’s banks. New water mirrors, higher ET values, and heterogeneous habitats with moderate disturbance correlate to high bird diversity. Reservoirs used for touristic purposes are related to new urbanizations and generalist birds.