Influence of transient storage on stream nutrient uptake based on substrata manipulation
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Quantification of the transient storage zone (As) has become critical in stream biogeochemical studies addressed to examine factors controlling nutrient uptake. It is expected that higher As may enhance the interaction between nutrients and biota and thus, increase nutrient uptake. However, results from the literature are controversial. We hypothesized that besides of the size of As, the intrinsic physical and biological characteristics of stream structures that generate As are also relevant for nutrient uptake. We performed 24 additions of phosphate, ammonium, and chloride in four reaches of a man-made channel where we introduced three types of naturally colonized substrata packs (mud, sand and cobbles) to modify As. We estimated ammonium and phosphate uptake coefficients in both the main channel and As using a solute transport model (OTIS-P) and compared the results among reaches with different substrata types. The introduction of substrata packs decreased water velocity and increased As similarly among treatments. Nutrient uptake coefficients in the main channel were similar among reaches with different type substrata packs; however, nutrient uptake coefficients measured in As differed among them as well as the ratio between ammonium and phosphorus uptake coefficients in As, which were 1.6 in reaches with mud packs and 0.02 in reaches with sand or cobble packs. Results obtained in this study suggest that the contribution of As in nutrient uptake not only depends on the size of As but on the type of materials used to increase As, and thus, have biogeochemical implications on restoration projects aimed to modify channel morphology.
KeywordsNutrient cycling Transient storage Nutrient assimilation Ammonium Phosphorus Stream
The authors would like to thank Daniel von Schiller and Simone Mariani for their comments and discussions on earlier drafts that helped to develop the paper, Rob Runkel for his help on the use of OTIS-P, and Susanna Pla for her laboratory assistance. Financial support was provided by the European Union through the EURO-LIMPACS project (ref. GOCE-CT-2003-505540, http://www.eurolimpacs.ucl.ac.uk), by the Spanish Government through the NICON project (ref. CGL2005-07362-C02), and by the National Science Foundation (EAR 04-09534 and EAR 08-38338).
- APHA (1998) Standard methods for the examination of water and wastewater, 19th edn. American Public Health Association, Washington, DCGoogle Scholar
- Gordon ND, McMahon TA, Finlayson BL (1992) Stream hydrology: an introduction for ecologists. Wiley, ChichesterGoogle Scholar
- Mulholland PJ, Tank JL, Sanzone DM, Wollheim WM, Peterson BJ, Webster JR, Meyer JL (2000) Nitrogen cycling in a forest stream determined by a 15N tracer addition. Ecol Monogr 70:471–493Google Scholar
- Runkel RL (1998) One-dimensional transport with inflow and storage (OTIS): A solute transport model for streams and rivers. US Geological Survey Water-Resources Investigation report 98-4018. US Geologica, Survey, Denver. Available from http://co.water.usgs.gov/otis
- Webster JR, Mulholland PJ, Tank JL, Valett HM, Dodds WK, Peterson BJ, Bowden WB, Dahm CN, Findlay S, Gregory SV, Grimm NB, Hamilton SK, Johnson SL, Martí E, Mcdowell WH, Meyer JL, Morrall DD, Thomas SA, Wollheim WM (2003) Factors affecting ammonium uptake in stream: an inter-biome perspective. Freshw Biol 48:1329–1352CrossRefGoogle Scholar