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Understanding Dissolved Organic Matter Biogeochemistry Through In Situ Nutrient Manipulations in Stream Ecosystems
Published on: October 29, 2016
Decoupling the direct and indirect effects of nitrogen deposition on ecosystem function
Pete Manning1, John E Newington, Helen R Robson
1Natural Environment Research Council Centre for Population Biology, Department of Biological Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire SL5 7PY, UK. p.manning@imperial.ac.uk
Ecology Letters
|August 24, 2006
Summary
Elevated nitrogen (N) deposition directly impacts plant growth and ecosystem function more than indirect effects from plant community changes. Long-term carbon storage may decrease under high nitrogen conditions.
Area of Science:
- Ecology
- Environmental Science
- Biogeochemistry
Background:
- Terrestrial ecosystems face significant alterations due to increased nitrogen (N) inputs.
- Disentangling direct N effects on plant physiology and soil biogeochemistry from indirect effects via plant community shifts is complex.
Purpose of the Study:
- To experimentally decouple and quantify the direct and indirect effects of nitrogen deposition on ecosystem functioning.
- To assess the contributions of these effects to changes in carbon, nitrogen, and water cycling.
Main Methods:
- Established model terrestrial ecosystems with high and low nitrogen deposition rates.
- Planted both high and low nitrogen plant community compositions within these ecosystems.
- Quantified impacts on plant physiology, soil biogeochemistry, and ecosystem cycling.
Main Results:
- Direct effects of nitrogen on plant growth were found to be the dominant driver of ecosystem responses.
- High nitrogen plant species composition led to reduced long-term carbon storage.
- Nitrogen deposition significantly altered carbon, nitrogen, and water cycling.
Conclusions:
- Direct impacts of nitrogen deposition on ecosystem function are substantial compared to indirect effects from plant community changes.
- Management strategies for nitrogen deposition should prioritize understanding and mitigating direct physiological effects.
- Long-term ecosystem carbon sequestration may be compromised by shifts in plant community composition under elevated nitrogen.
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