Long-term phosphorus assimilative capacity in freshwater wetlands: A new paradigm for sustaining ecosystem structure and function

Published

Journal Article

Statistical analysis of a North American Wetland Database (NAWDB) allowed us to develop a mass loading model that was used to separate P assimilative capacity (defined as P absorption with no significant ecosystem change and no elevated P output) from storage capacity (maximum storage) in wetlands. Our analysis indicates that, given ample supplies of other nutrients, average P assimilative capacity (PAC) in North American wetlands is near 1 g m-2 yr-1. From this analysis, we proposed a 'One Gram Assimilative Capacity Rule' for P loadings within natural freshwater wetlands if long-term storage of P, maintenance of community structure and function, and low P effluent concentrations are required. An Everglades test site supports our hypothesis that natural wetlands will lose native species, become P saturated in a few years, and export unacceptable amounts of phosphate when phosphorus loading exceeds PAC. Moreover, our findings clearly demonstrate that even P-limited wetlands have the capacity to assimilate low levels of P loadings without significant changes in ecosystem structure and function.

Full Text

Duke Authors

Cited Authors

  • Richardson, CJ; Qian, SS

Published Date

  • May 15, 1999

Published In

Volume / Issue

  • 33 / 10

Start / End Page

  • 1545 - 1551

International Standard Serial Number (ISSN)

  • 0013-936X

Digital Object Identifier (DOI)

  • 10.1021/es980924a

Citation Source

  • Scopus