Collaborative Research: Response of Tropical Stream Ecosystem Structure and Function to Amphibian Extinctions

Drexel University, Philadelphia PA

Investigators

Abstract

Abstract. Amphibians represent an important energetic link between aquatic and terrestrial habitats, particularly in the tropics where diversity and abundance are very high. Tadpoles feed on algae and organic materials and transfer energy and nutrients from aquatic to terrestrial habitats when they emerge as frogs, and frogs transfer energy and materials back when they return to water to breed. However, amphibian populations have declined dramatically around the world, including massive losses in 13 Latin American countries in the last 20 years. Most declines involve disappearances of over 75% of amphibians at a given site. This research will examine the consequences of amphibian declines on tropical streams by investigating how losses alter stream biodiversity, energy flow in streams, in-stream and streamside food webs, and energy exchange between streams and terrestrial habitats. This will be accomplished through intensive comparisons of stream communities, food webs, and energy flow patterns in Panamanian highland streams with natural amphibian populations and nearby streams where amphibians have recently disappeared. Preliminary studies suggest that amphibian declines will have large-scale effects on streams, including changes in community structure, shifts to increased importance of algal energy sources, reduced downstream transport of organic materials, and reduced energy transfer from streams to terrestrial habitats. Broader impacts. The broader implications of this research are that findings will be relevant to an urgent problem (i.e. amphibian declines) influencing many regions. The proposed research will also provide opportunities for students from Latin America and the U.S. to work on an important, large-scale environmental issue and will further collaboration between the 3 institutions involved and other scientists researching related issues in the tropics.