Material Spiraling in Stream Corridors: A Telescoping Ecosystem Model

摘要: Stream ecosystems consist of several subsystems that are spatially distributed concentrically, analogous to the elements a simple telescope. Subsystems include central surface stream, vertically and laterally arrayed saturated sediments (hyporheic parafluvial zones), most distal element, riparian zone. These zones hydrologically connected; thus water its dissolved suspended load move through all these as it flows downstream. In any given subsystem, chemical transformations result in change quantity materials transport. Processing length is subsystem required “process” an amount substrate equal advective input. Long processing lengths reflect low rates material cycling. provides dimension each cylindrical element telescope specific (for example, stream), instance, nitrate), process (denitrification, for example). Disturbance causes increase. decreases during succession following disturbance. The whole stream-corridor ecosystem consists nested extend retract, much would telescope, response disturbance regime. This telescoping model (TEM) can improve understanding retention running systems; is, their “nutrient filtration” capacity. We hypothesize by flooding alters this capacity proportion both intensity relative effect on subsystem. expect more zone) show highest resistance floods. contrast, we predict postflood recovery functions such (that resilience) will be decrease laterally. Resistance resilience inversely correlated separated. further cross-linkages between adjacent enhance system whole. Whole-ecosystem retention, transformation, transport viewed function extent, lateral vertical linkage,