Evaluating the effects of upstream lakes and wetlands on lake phosphorus concentrations using a spatially-explicit model

Tao Zhang, Patricia A. Soranno, Kendra Spence Cheruvelil, Daniel B. Kramer, Mary Tate Bremigan, Arika Ligmann-Zielinska

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


Lake phosphorus concentrations are strongly influenced by the surrounding landscape that generates phosphorus loads and water inflow to lakes, and the physical characteristics of the lake that determine the fate of these inputs. In addition, the presence, connectivity, and configuration of upstream lakes and wetlands likely affect downstream lake phosphorus concentrations. These freshwater landscape features have only sometimes been incorporated into phosphorus loading models, perhaps because of the need for spatially-explicit approaches that account for their location and hydrologic configuration. In this paper, we developed a lake phosphorus concentration model that includes three modules to estimate phosphorus loading, water inflow, and phosphorus retention, respectively. In modeling phosphorus loading and water inflow, we used a spatially-explicit approach to address their export at sources and their attenuation along flow-paths. We used 161 headwater lakes for model calibration and 28 headwater lakes for model validation. Using the calibrated model, we examined the effects of upstream lakes and wetlands on downstream lake phosphorus concentrations. To examine the effects of upstream lakes, we compared the output of the calibrated model for three additional datasets (208 lakes in total) that contained increasing area of upstream lakes. To examine the effect of upstream wetlands, we used the calibrated model to compare flow-path cell series that contained wetlands and those that did not. In addition, we simulated catchments in which all wetlands were converted to forest and recalculated downstream lake phosphorus concentrations. We found that upstream lakes decreased the phosphorus concentrations in downstream lakes; and, counter-intuitively, we found that wetlands increased phosphorus concentrations in most downstream lakes. The latter result was due to the fact that although wetlands reduced phosphorus loads to downstream lakes, they also reduced water inflow to downstream lakes and thus increased the phosphorus concentration of inflows to lakes. Our results suggest that when modeling lake phosphorus concentrations, freshwater features of the landscape and their spatial arrangement should be taken into account.

Original languageEnglish (US)
Pages (from-to)1015-1030
Number of pages16
JournalLandscape Ecology
Issue number7
StatePublished - Aug 2012
Externally publishedYes

Bibliographical note

Funding Information:
Acknowledgments Financial support for this work was provided by the Center for Water Sciences at Michigan State University (MSU). We thank Katie Droscha for assembling the lake nutrient and LULC datasets, and C. Emi Fergus for help with the literature related to wetland effects and comments on earlier drafts. Thanks to Sarah AcMoody, Justin Booth, and Dave Lusch at MSU’s Remote Sensing and GIS Outreach and Research Services for consultation and creation of some of the databases used in this study as well as for catchment delineations and LULC summaries. We also thank the anonymous reviewers for their valuable comments and suggestions.

Copyright 2012 Elsevier B.V., All rights reserved.


  • Distance-attenuation effect
  • Flow-path
  • Lake phosphorus concentration
  • Spatially-explicit modeling
  • Upstream lake
  • Wetland


Dive into the research topics of 'Evaluating the effects of upstream lakes and wetlands on lake phosphorus concentrations using a spatially-explicit model'. Together they form a unique fingerprint.

Cite this