INFORMATION LENGTH - SPATIAL AND TEMPORAL PARAMETERS AMONG STREAM BACTERIAL ASSEMBLAGES

Bacteria, while known to be an integral part of all ecosystems, are se ldom studied except as a single taxonomic unit. Few ecological studies even acknowledge the extraordinary functional and species diversity o f bacteria. Recent research has elucidated some important facts about bacteria in stream ecosystems. For instance, the dynamics of bacterial genomes within a stream suggest that populations of these organisms a re 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: co lonization distance and information length Colonization distance (D-c) is the maximum distance downstream from original colony establishment at which a new colony of bacteria can be established. Information len gth (L-l) is defined as the maximum length over which a gene has an ef fect on an ecosystem process independent of a specific host. These ter ms are modeled relative to the average temporal energy load (joules/mi n) in the stream. Energy inputs that exceed biologically defined limit s of use result in ecosystem energy leaks regardless of information le ngth. Our models predict that information length should be shorter in montane streams than in Coastal plain streams of southeastern USA. Fur thermore, assuming equal average energy load between streams, the stre am with the largest energy load variance will leak more energy downstr eam. Therefore, temperate streams should be less efficient than tropic al streams at utilizing energy within a reach.