Variable Effects of Nutrients, Productivity, Consumption and the Food Pulse on Floodplain River Ecosystems

Texas A&M Research Foundation, College Station TX

Investigators

Abstract

ABSTRACT P.I. Kirk O. Winemiller Institution: Texas A & M University Proposal Number: DEB-0089834 This research addresses the importance and strength of mechanisms involved in feedbacks and interactions among major components of lower food webs in floodplain river ecosystems. The work will explore how temporal heterogeneity due to seasonal flood pulses influences these food webs. Floods lead to a nutrient pulse into aquatic ecosystems that varies over time and over space. These floods may cause time lags in the reciprocity of consumer resource interactions, so that donor-control does not dominate the system continuously. A series of fish exclosure/enclosure experiments will be used to explore fish effects on alge and particulate organic matter over the annual hydrocycle. Experiments will be conducted during three phases of the hydrocycle. The research will be completed in South American tropical riverine floodplains. The work will be significant in enhancing scientific understanding of the relative effects of donor vs. consumer control in relation to ecosystem dynamics and it will help elucidate how ecosystems link species to landscapes.