Poster Details
MACROINVERTEBRATE RESPONSE TO CHANGES IN FLOW REGIME IN TROPICAL HEADWATER STREAMS OF COSTA RICA
Predictions of global climate change suggest extreme events will increase in their intensity and frequency. In parts of Costa Rica, the likelihood of drought and higher temperatures during El Niño cycles may increase, although during La Niña events these areas will likely receive increased rainfall and flooding. To provide insights into these possible changes we are quantifying the effects of seasonal flow variation on the macroinvertebrate communities within two headwater streams, one intermittent and the other perennial, in the Puntarenas province of Costa Rica. We are sampling macroinvertebrates monthly over the course of a year using surber and grab samples. Preliminary results show that invertebrate abundance increased as the rainy season progressed, although declined at the end of the season, during the period of highest annual rainfall. Abundance was greatest in leaf litter microhabitats, where Chironomidae and the black fly Simulium spp. were dominant. Invertebrate abundance also tended to increase in pools during peak rainfall. These observations provide insights into the potential resistance and resilience of macroinvertebrate communities to extreme events in neotropical headwater streams.
Darixa Hernandez Abrams (Primary Presenter/Author), US Army Corps of Engineers, darixa.hernandez@uga.edu;
Scott Connelly ( Co-Presenter/Co-Author), University of Georgia, scottcon@uga.edu;
Seth Wenger ( Co-Presenter/Co-Author), University of Georgia, sethwenger@fastmail.fm;