Freshwater ecology. Experimental nutrient additions accelerate terrestrial carbon loss from stream ecosystems.
Nutrient pollution of freshwater ecosystems results in predictable increases in carbon (C) sequestration by algae. Tests of nutrient enrichment on the fates of terrestrial organic C, which supports riverine food webs and is a source of CO2, are lacking. Using whole-stream nitrogen (N) and phosphorus (P) additions spanning the equivalent of 27 years, we found that average terrestrial organic C residence time was reduced by ~50% as compared to reference conditions as a result of nutrient pollution. Annual inputs of terrestrial organic C were rapidly depleted via release of detrital food webs from N and P co-limitation. This magnitude of terrestrial C loss can potentially exceed predicted algal C gains with nutrient enrichment across large parts of river networks, diminishing associated ecosystem services.
Odum School of Ecology, University of Georgia, Athens, GA 30602, USA. rosemond@uga.edu.
Amy D
AD
Rosemond
Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA.
Jonathan P
JP
Benstead
Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.
Phillip M
PM
Bumpers
Department of Biology, Coastal Carolina University, Conway, SC 29528, USA.
Vladislav
V
Gulis
Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.
John S
JS
Kominoski
Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.
David W P
DW
Manning
Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA.
Keller
K
Suberkropp
Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.
J Bruce
JB
Wallace
D031002:Acer; D018533:Biomass; D057965:Carbon Sequestration; D020387:Food Chain; D031567:Liriodendron; D009584:Nitrogen / Q000737:chemistry; D009747:Nutritional Physiological Phenomena; D010758:Phosphorus / Q000737:chemistry; D018515:Plant Leaves; D029963:Quercus; D029793:Rhododendron; D045483:Rivers / Q000737:chemistry*; D014876:Water Pollution
D010758:Phosphorus; D009584:Nitrogen