Joel C. Trexler Jennifer Richards Daniel L. Childers David Lee A. L. Edwards Leonard J. Scinto Krish Jayachandran Gregory E. Noe Ronald D. Jones Evelyn Gaiser 2005 <p><span>Few studies have examined long-term ecological effects of sustained low-level nutrient enhancement on wetland biota. To determine sustained effects of phosphorus (P) addition on Everglades marshes we added P at low levels (5, 15, and 30 μg L</span>⁻¹<span>&nbsp;above ambient) for 5 yr to triplicate 100-m flow-through channels in pristine marsh. A cascade of ecological responses occurred in similar sequence among treatments. Although the rate of change increased with dosing level, treatments converged to similar enriched endpoints, characterized most notably by a doubling of plant biomass and elimination of native, calcareous periphyton mats. The full sequence of biological changes occurred without an increase in water total P concentration, which remained near ambient levels until Year 5. This study indicates that Everglades marshes have a near-zero assimilative capacity for P without a state change, that ecosystem responses to enrichment accumulate over time, and that downstream P transport mainly occurs through biota rather than the water column.</span></p> application/pdf 10.2134/jeq2005.0717 en ACSESS Cascading ecological effects of low-level phosphorus enrichment in the Florida Everglades article