Influence of land use change on amphibian species assemblages and larval development

Abstract

Land use alterations can have significant impacts on wetland ecosystems. One of the most notable impacts is altered flood regimes which can influence organisms dependent upon those waters. Amphibians, with their recent dramatic declines, are among those influenced by land use alterations. This study combined field and laboratory techniques to elucidate some of the factors influencing amphibian occurrence and survival in altered wetlands. The field component consisted of active searches and automated recording devices on fifteen headwater slope wetlands in southern Alabama. More rare and sensitive species were detected in wetlands with more forest in the surrounding area. Several species were positively associated with agricultural land use and one species (Eleutherodactylus planirostris) was positively associated with impervious surface area. A mesocosm experiment was conducted to examine the effects of altered flooding regimes on tadpole development in four different species. A species adapted to habitats with minimal water level fluctuations (Lithobates sphenocephalus) had higher survival in the control treatment and the lowest survival in the flashy, urban treatment. Hyla chrysoscelis had larger body sizes in a gradual flooding treatment than in the control or urban treatment.