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Updated: Mar 6, 2026
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Understanding Dissolved Organic Matter Biogeochemistry Through In Situ Nutrient Manipulations in Stream Ecosystems
Published on: October 29, 2016
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Nutrient addition accelerates leaf breakdown in an alpine springbrook
1Department of Limnology, EAWAG/ETH, Überlandstrasse 133, CH-8600 Dübendorf, Switzerland, , , , , , CH.
Oecologia
|March 18, 2017
Summary
Nutrient enrichment significantly accelerated organic matter breakdown in alpine streams. Increased leaf decomposition was linked to greater shredder insect feeding, highlighting nutrient impacts on stream ecosystems.
Area of Science:
- Ecology
- Environmental Science
- Aquatic Biology
Background:
- Organic matter breakdown is crucial for stream ecosystem functioning.
- Nutrient availability can influence decomposition rates and food web dynamics.
- Alpine spring ecosystems are sensitive to environmental changes.
Purpose of the Study:
- To investigate the impact of nutrient enrichment (phosphorus and nitrogen) on leaf litter decomposition in an alpine springbrook.
- To determine the role of macroinvertebrates and microbial communities in nutrient-mediated decomposition.
Main Methods:
- Alder leaf packs were used as a substrate for decomposition.
- Slow-release fertilizer briquettes were added to enrich leaf packs with phosphorus and nitrogen.
- Decomposition rates were quantified by mass loss, and fungal biomass and macroinvertebrate communities were assessed.
Main Results:
- Nutrient-enriched leaf packs decomposed significantly faster (k=0.0284 day⁻¹) than unfertilized ones (k=0.0137 day⁻¹), showing 30% greater mass loss.
- Fungal biomass and aquatic hyphomycete sporulation were similar between treatments, suggesting microbial activity was not the primary driver of accelerated decomposition.
- Fertilized packs supported significantly higher numbers and biomass of macroinvertebrates, particularly shredding stoneflies.
Conclusions:
- Nutrient enrichment enhances organic matter breakdown in alpine springbrooks.
- Increased shredder macroinvertebrate feeding, stimulated by nutrient addition, is the main driver of accelerated leaf decomposition.
- These findings underscore the sensitivity of alpine stream ecosystems to nutrient inputs.
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