SREL Reprint #2178

Information length: spatial and temporal parameters among stream bacterial assemblages

J Vaun McArthur1 and R. Cary Tuckfield2

1Savannah River Ecology Laboratory, Aiken, South Carolina 29802 USA
2Westinghouse Savannah River Company, Savannah River Technology Center, Aiken, South Carolina 29808 USA

Abstract: Bacteria, while known to be an integral part of all ecosystems, are seldom studied except as a single taxonomic unit. Few ecological studies even acknowledge the extraordinary functional and species diversity of bacteria. Recent research has elucidated some important facts about bacteria in stream ecosystems. For instance, the dynamics of bacterial genornes within a stream suggest that populations of these organisms are more stable temporally than spatially. We develop predictive models and testable hypotheses based on the information spiraling concept to describe the ecology of stream bacteria and to define 2 new terms: colonization distance and information length. Colonization distance (Dc) is the maximum distance downstream from original colony establishment at which a new colony of bacteria can be established. Information length (L1) is defined as the maximum length over whidi a gene has an effect on an ecosystem process independent of a specific host. These terms are modeled relative to the average temporal energy load (joules/min) in the stream. Energy inputs that exceed biologically defined limits of use result in ecosystem energy leaks regardless of information length. Our models predict that information length should be shorter in montane streams than in Coastal Plain streams of southeastern USA. Furthermore, assuming equal average energy load between streams, the stream with the largest energy load variance will leak more energy downstream. Therefore, temperate streams should be less efficient than tropical streams at utilizing energy within a reach.

Keywords: information spiraling concept, information length, colonization distance, energy load, bacteria, lotic

SREL Reprint #2178

McArthur, J V. and R.C. Tuckfield. 1997. Information length: spatial and temporal parameters among stream bacterial assemblages. Journal of the North American Benthological Society 16:347-357.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).