Abstract
Proper assessment of ecological data must consider uncertainty. However, reported estimation of uncertainty in calculated values of nutrient spiraling indices is rare. Interpretations based on single values of spiraling indices, may therefore be unwittingly flawed. We investigated the sources of analytical uncertainty in the nutrient concentrations used to calculate two spiraling indices, uptake length (S w ) and uptake velocity (V f ), and used Monte Carlo Simulation (MCS) to estimate the resultant uncertainty in index values. We also examined the effect of the level of nutrient enrichment on the magnitude of index uncertainty. Outcomes under high and low nutrient uptake capacity were compared by performing nutrient addition experiments in two streams with contrasting ambient nutrient concentrations. We found that small differences (or uncertainties) in the average plateau nutrient concentration resulted in large uncertainties in spiraling indices. The uncertainty resulted from a combination of small differences in nutrient concentrations between upstream and downstream stations (particularly for the low uptake case), the low nutrient concentration added into the stream, and the sample matrix and storage. The stream with low nutrient uptake capacity had larger relative uncertainties in S w than when the nutrient uptake capacity was high. The presence of such errors demands that S w and V f values should be reported with uncertainty, rather than the normal practice of a single calculated value.
Similar content being viewed by others
References
Anagnostopoulou PI, Koupparis MA. 1986. Automated flow-injection phenol red method for determination of bromide and bromide salts in drugs. Anal Chem 58(2):322–6
APHA. 1998. Standard methods for the examination of water and wastewater. American Public Health Association, American Water Works Association, Water Pollution Control Federation, Washington DC
Bernhardt ES. 2002. Lessons from kinetic releases of ammonium in streams of Hubbard Brook Experimental Forest. Verh Int Ver Limnol 28:429–33
Bernhardt ES, Likens GE. 2002. Dissolved organic carbon enrichment alters nitrogen dynamics in a forest stream. Ecology 83(6):1689–700
Carpenter SR. 2002. Ecological futures: building an ecology of the long now. Ecology 83(8):2069–83
Carpenter SR, Ludwig D, Brock WA. 1999. Management of eutrophication for lakes subject to potentially irreversible change. Ecol Appl 9(3):751–71
Davis JC, Minshall GW, Robinson CT, Landres P. 2001. Monitoring wilderness stream ecosystems. General Technical Report RMRS-GTR-70. Ogden, UT: US Department of Agriculture, Forest Service, Rocky Mountain Research Station. 137 p
De Bièvre P. 1997. Measurement results without statements of reliability (uncertainty) should not be taken seriously. Accredit Qual Assur 2:269
Dodds WK, Lopez AL, Bowden WB, Gregory S, Grimm NB, Hamilton SK, Hershey AE, Marti E, McDowell WH, Meyer JL, Morrall D, Mulholland PJ, Peterson BJ, Tank JL, Valett HM, Webster JR, Wollheim W. 2002. N uptake as a function of concentration in streams. J North Am Benthol Soc 21:206–20
Doyle MW, Stanley EH, Harbor JM. 2003. Hydrogeomorphic controls on phosphorus retention in streams. Water Resour Res 39(6):1–17
Fedra K, Van Straten G, Beck MB. 1981. Uncertainty and arbitrariness in ecosystems modeling: a lake modelling example. Ecol Model 13:87–110
Fisher SG, Sponseller RA, Heffernan JB. 2004. Horizons in stream biogeochemistry: flowpaths to progress. Ecology 85:2369–79
Gardolinski PCFC, Grady H, Achterberg EP, Gledhill M, Tappin AD, House WA, Worsfold PJ. 2001. Comparison of sample storage protocols for the determination of nutrients in natural waters. Water Res 35(15):3670–8
Hall RO Jr., Bernhardt ES, Likens GE. 2002. Relating nutrient uptake with transient storage in forested mountain streams. Limnol Oceanogr 47(1):255–65
Hart BT, Freeman P, McKelvie ID. 1992. Whole-stream phosphorus release studies: variation in uptake length with initial phosphorus concentration. Hydrobiologia 235/236:573–84
Harvey JW, Wagner BJ, Bencala KE. 1996. Evaluating the reliability of the stream tracer approach to characterize stream-subsurface water exchange. Water Resour Res 32(8):2441–51
Hatt B, Fletcher TD, Walsh CJ. 2004. The influence of urban density and drainage infrastructure on the concentrations and loads of pollutants in small streams. Environ Manage 34:112–24
Horwitz W, Kamps LR, Boyer KW. 1980. Quality assurance in the analysis of foods for trace constituents. J Assoc Official Anal Chem 63(6):1344–453
Hudson R, Fraser J. 2002. Alternative methods of flow rating in small coastal streams. Forest Research Extension Note EN-014 (Hydrology). Vancouver Forest Region
Ludwig D. 1996. Uncertainty and the assessment of extinction probabilities. Ecol Appl 6(4):1067–76
Kotlash AR, Chessman BC. 1998. Effects of water sample preservation and storage on nitrogen and phosphorus determinations: implications for the use of automated sampling equipment. Water Res 32(12):3731–37
Loehle C. 1987. Errors of constructions, evaluation, and inference: a classification of sources of error in ecological models. Ecol Model 36:297–314
Marti E, Sabater S. 1996. High variability in temporal and spatial nutrient retention in Mediterranean streams. Ecology 77(3):854–69
Mulholland PJ, Tank JL, Webster JR, Bowden WB, Dodds WK, Gregory SV, Grimm NB, Hamilton SK, Johnson SL, Marti E, McDowell WH, Merriam JH, Meyer JL, Peterson BJ, Valett HM, Wollheim WM. 2002. Can uptake length in streams be determined by nutrient addition experiments? Results from an interbiome comparison study. J North Am Benthol Soc 21(4):544–60
Mulholland PJ, Tank JL, Sanzone DM, Webster JR, Wollheim WM, Peterson BJ, Meyer JL. 2000. Ammonium and nitrate uptake lengths in a small forested stream determined by 15N tracer and short-term nutrient enrichment experiments. Verh Int Ver Limnol 27:1320–5
Newbold JD, Elwood JW, O’Neill RV, Winkle WV. 1981. Measuring nutrient spiraling in streams. Can J Fish Aquat Sci 38:860–3
Payn RA, Webster JR, Mulholland PJ, Valett HM, Dodds WK. 2005. Estimation of stream nutrient uptake from nutrient addition experiments. Limnol Oceanogr Methods 3:174–82
Peterson BJ, Wollheim WM, Mulholland PJ, Webster JR, Meyer JL, Tank JL, Marti E, Bowden WB, Valett HM, Hershey AE, McDowell WH, Dodds WK, Hamilton SK, Gregory S, Morrall DD. 2001. Control of nitrogen export from watersheds by headwater streams. Science 292:86–90
Pielke Jr. RA, Conant RT. 2003. Best practices in prediction for decision-making: lessons from the atmospheric and earth sciences. Ecology 84(6):1351–8
Ramsey MM. 1998. Sampling as a source of measurement uncertainty: techniques for quantification and comparison with analytical sources. J Anal Atomic Spectrom 13:97–104
Robert PR, Casella G. 2004. Monte Carlo statistical methods. New York: Springer
Runkel RL. 2002. A new metric for determining the importance of transient storage. J North Am Benthol Soc 21(4):529–543
Simon KS, Townsend CR, Biggs BJF, Bowden WB. 2005. Temporal variation of N and P uptake in 2 New Zealand streams. J North Am Benthol Soc 24:1–18
Snowling SD, Kramer JR. 2001. Evaluating modeling uncertainty for model selection. Ecol Model 138:17–30
Spiegelhalter D, Thomas A, Best N, Lunn D. 2004. Winbugs Version 1.4.1. User Manual. http://www/mrc-bsu.cam.ac.uk/bug (last accessed 30 July 2006)
Stream Solute Workshop. 1990. Concepts and methods for assessing solute dynamics in stream ecosystems. J North Am Benthol Soc 9:95–119
Sulfikar, Grace MR, Hart BT. 2006. Can nutrient spiraling measurements detect seasonal pattern of nutrient use? A case study in Lyrebird Creek, a forested stream in The Dandenong Ranges, Victoria. Water, air and soil pollution: focus 6:403–411
Taylor SL, Roberts SC, Walsh CJ, Hatt BE. 2004. Catchment urbanization and increased benthic algal biomass in streams: linking mechanisms to management. Freshw Biol 49:835–51
Thompson M, Ellison SLR. 2005. A review of interference effects and their correction in chemical analysis with special reference to uncertainty. Accredit Qual Assur 10(3):82–97
Valett HM, Crenshaw CL, Wagner PF. 2002. Stream nutrient uptake, forest succession, and biogeochemical theory. Ecology 83(10):2888–901
Webster JR, Meyer JL. 1997. Organic matter budgets for streams: a synthesis. J North Am Benthol Soc 16:141–61
Wilcock RJ, Scarsbrook MR, Costley KJ, Nagels JW. 2002. Controlled release experiments to determine the effect of shade on nutrient retention in a lowland stream. Hydrobiologia 485(1–3):153–62
Wintle BA, McCarthy MA, Volinsky CT, Kavanagh RP. 2003. The use of Bayesian model averaging to better represent uncertainty in ecological models. Conserv Biol 17(6):1570–90
WSC. 2001. NATA-certified quality assurance protocol for flow injection analysis. Water Studies Centre, Monash University, Australia
ACKNOWLEDGMENTS
The authors wish to acknowledge the helpful advice given by Dr Emily Bernhardt and two anonymous reviewers on an earlier version of this manuscript. We thank Shane Perryman for technical advice and suggestions, and A. Saefumillah, Z. Fikar, K. Lansdown, K O’Dea, S. Hall, S. Ammade, Quyen, W. Diah, B. Rumhayati, B. Atkinson, and E. Harbott for assistance with fieldwork. This study was partially funded by an Australian Development Scholarship (Sulfikar).
Author information
Authors and Affiliations
Corresponding author
Electronic Supplementary Material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Hanafi, S., Grace, M., Webb, J.A. et al. Uncertainty in Nutrient Spiraling: Sensitivity of Spiraling Indices to Small Errors in Measured Nutrient Concentration. Ecosystems 10, 477–487 (2007). https://doi.org/10.1007/s10021-007-9031-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10021-007-9031-1