This Americas Program Dissertation Enhancement Grant will support the research of Mr. Marcelo Ardon Sayao, under the direction of Dr. C.M. Pringle at the Institute of Ecology, University of Georgia. Dr. Monika Springer of the University of Costa Rica will assist with some aspects of the research and will help to coordinate undergraduate student involvement at the U. of Costa Rica. The project will focus on a vital ecosystem process, the decomposition of organic matter in tropical climate streams, at the La Selva Biological Station, in Costa Rica.
In an era of human alteration to global nutrient cycles, it is critical to understand the effects of nutrients on ecosystem processes. The proposed research will improve our ability to predict how streams will respond to nutrient deposition. Specific objectives will: 1) examine effects of initial leaf litter chemistry on breakdown processes in a Neotropical lowland stream and compare the results to another tropical site and a temperate site; 2) assess the influence of interactions between litter carbon quality and dissolved nutrients on microbial and invertebrate leaf litter processing; and 3) use artificial substrates of varying carbon quality to examine microbial response to water nutrients. Funding from the Americas Program will improve this research project by allowing comparisons between tropical and temperate sites through chemical analysis of a broad range of tropical and temperate species and help to develop and enhance an artificial substrate technique. Broader impacts of this research also include strengthening relationships between Costa Rican and U.S. academic institutions through the advancement of training of graduate and undergraduate students in both countries.
