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09:38
Understanding Dissolved Organic Matter Biogeochemistry Through In Situ Nutrient Manipulations in Stream Ecosystems
Published on: October 29, 2016
In-stream biogeochemical processes of a temporary river
Ourania Tzoraki1, Nikolaos P Nikolaidis, Yorgos Amaxidis
1Department of Environmental Engineering, Technical University of Crete, 73100 Chania, Greece.
Environmental Science & Technology
|June 28, 2007
Summary
In-stream processes significantly impact the Krathis River
Area of Science:
- Environmental Science
- Hydrology
- Biogeochemistry
Background:
- The Krathis River in Greece experiences high annual flow variability.
- Transmission losses are substantial, particularly during dry periods, impacting its hydrologic and biogeochemical status.
Purpose of the Study:
- To investigate how in-stream processes influence the hydrologic and biogeochemical regime of the Krathis River estuary.
- To quantify nutrient release from river sediments and its contribution to overall nutrient flux.
Main Methods:
- Field assessments of river reach hydrology and water chemistry.
- Sediment analysis to determine nutrient content and mineralization potential.
- Monitoring of environmental factors like temperature and soil moisture.
Main Results:
- Transmission losses significantly enhance nutrient release from river sediments, contributing 11% to the dissolved inorganic nitrogen flux.
- Nitrogen species release is temperature-dependent; phosphate release is limited by low concentrations.
- Fine-grained sediments form "hot spots" that mobilize nutrients and suspended matter during fall "first flush" events.
- Sediment mineralization capacity remains significant even at 40% soil moisture.
Conclusions:
- In-stream processes, particularly sediment dynamics, play a critical role in the Krathis River's biogeochemical cycling.
- Nutrient release from sediments significantly impacts water quality and coastal zone inputs.
- Temporary rivers are sensitive ecosystems vulnerable to climate change, necessitating further study of in-stream processes.
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