|Ettema, Christian - UNIVERSITY OF GEORGIA|
|Coleman, David - UNIVERSITY OF GEORGIA|
Submitted to: Soil Biology and Biochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 10, 1999
Publication Date: December 10, 1999
Citation: Ettema, C.H., Lowrance, R.R., Coleman, D.C. 1999. Riparian soil response to surface nitrogen input: the indicator potential of free-living soil nematide populations. Soil Biology and Biochemistry 1625-1638. Interpretive Summary: One of the most important human alterations of global ecological conditions has been the huge increase in available nitrogen (N) introduced into terrestrial and aquatic ecosystems through industrial N fixation for agriculture. Certain ecosystems such as wetlands and riparian zones are known to be effective at trapping N. Much of the trapping ability or ability to act as an N sink is due to uptake of N by vegetation and micro- bial removal of N by denitrification. Unfortunately, long-term enrichment of ecosystems with N may lead to N saturation and a decrease in ability of ecosystems to remove or trap N and thus a decrease in water quality improvement function of the ecosystem. These changes may be manifested through changes in microbial dynamics and microbial biomass in soil of the affected ecosystem. Nematodes are among the most diverse and abundant groups of organisms in soil ecosystems. Because of their abundance and widespread occurrence in soils, a number of programs such as the USEPA Environmental Monitoring and Assessment program have suggested using nematodes as indicators of soil ecosystem health. Part of the assessment of soil ecosystem health involves assessment of effects of long-term, chronic N enrichment. Results from an N addition experiment indicate that nematodes can probably be used as indicators of N enrichment and potential N saturation when combined with other ecosystem measures. These results mean that more tools are available to scientists to assess the long-term changes in terrestrial ecosystems due to human mediated N enrichment.