Document: JAM-3-21-1

The effects of prey and top-predator addition on the inquiline community of the pitcher plant, Sarracenia purpurea.

KNEITEL, J.M.* and T.E.MILLER

Department of Biological Science, Florida State University, Tallahassee, FL 32306-1100 ¹

Abstract:
The relative effects of top-down and bottom-up control in communities continues to be a central question in community ecology. One current view is that the role of each of these forces is determined by the nature of the interactions among species within intermediate trophic levels. The effects and interactions between top-down and bottom-up forces were the focus of this study using the inquiline communities found in the water-filled leaves of the pitcher plant, _Sarracenia purpurea_. A press field experiment was conducted in which the abundances of resources (dead ants) and the top-predators (larvae of the mosquito, _Wyeomiia smithii_) were each maintained at three levels in a factorial design for 22 days. Abundances of mites, rotifers, protozoans, and bacteria all increased significantly with prey addition. Protozoan and bacteria species richness also increased with increasing resource levels. Increases in top-predator density decreased rotifer abundance and bacteria species richness. Top-down and bottom-up forces both had strong, but different, effects on the abundance and richness of intermediate trophic levels with no apparent interactions between them. The abundance and richness of the whole inquiline community is resource limited, whereas predator limitation targets a particular set of groups.

Keywords: _Sarracenia purpurea_, inquiline community, top-down, bottom-up, press experiment

This abstract is being presented at: 11:10 AM in session:
Symposium # 19: Carnivorous Plants as Model Ecological Systems.