Early Registration Deadline
12 February 2010

Travel Award & Grant Recipients Notified
March 2010

Authors Notified
April 2010

Schedule Posted
January 2010

Negroni-Miranda, A. ., University of Puerto Rico - Cayey/ Department of Biology, Cayey, Puerto Rico, shizenko@gmail.com
Shea, C. ., University of Vermont/ Environmental Sciences, Burlington, USA, cshea@uvm.edu
Torres, P. J., University of Georgia/ Odum School of Ecology, Athens, USA, pjtorres@uga.edu
Colon-Gaud, C. ., University of Puerto Rico - Rio Piedras/ Institute for Tropical Ecosystem Studies, San Juan, Puerto Rico, checo@ites.upr.edu
Ramirez, A. ., University of Puerto Rico - Rio Piedras/ Institute for Tropical Ecosystem Studies, San Juan, Puerto Rico, aramirez@ites.upr.edu

MACROCONSUMER EFFECTS ON STREAM BENTHOS AND ORGANIC MATTER PROCESSING IN A TROPICAL HEADWATER STREAM: ARE SHRIMPS MORE ACTIVE AT NIGHT?

Stream macroconsumers are capable of influencing ecosystem processes and properties such as leaf breakdown, benthic community structure, and resource standing stocks. While several studies have addressed the individual influences of shrimps and fishes on litter decay and benthic environments, few studies have assessed the significance of nocturnal versus diurnal behavior of these consumers on ecosystem processes. We used an electric exclusion technique to assess the effect of macroconsumers on leaf breakdown and sediment removal in five blocks along a 130m stream reach in the Luquillo LTER. Each block contained electrified day and night frames, each with corresponding controls. We found no significant differences between the rates of leaf litter decomposition (P = 0.74) or organic sediment stocks (P = 0.45) in day, night, and control treatments. Despite the lack of significant effects, day shrimp exclusions had the highest rates of leaf decomposition (k = 0.010). No clear patterns were observed for organic sediment accrual in benthic substrates. Results suggest that shrimps can be equally active both nocturnally and diurnally and can thus influence patterns in ecosystem processes.

Poster presentation

Session #:T24
Date: 06-10-10
Time: 17:30 - 19:30

Presentation is given by student: Yes