The effects of resource subsidy duration in a detritus-based stream ecosystem: a mesocosm experiment

1. Most resource subsidies are temporally variable, dynamically affecting the consumer populations, community structures, and ecosystem functions of recipient ecosystems. Temporally variable resource subsidies are characterized by the duration, magnitude, timing, and frequency of resource subsidy inputs. These different characteristics may have different mechanisms by which to affect recipient ecosystems.

2. Few studies have examined the duration of resource subsidy inputs on recipient ecosystems, although there exist previous studies focusing on magnitude, timing, and frequency.

3. We provide the first experimental test of the effects of subsidy duration on a stream ecosystem by using an outdoor mesocosm experiment, in which we directly manipulated the subsidy duration (pulsed vs. prolonged) of terrestrial invertebrate input into the mesocosm.

4. Given the same overall amount of terrestrial invertebrate subsidy were added, a prolonged subsidy allowed large-stage fish to effect...