Relating structure to function: determining functionally-relevant descriptors of biogeochemical structure for denitrification in six central Pennsylvania wetlands

The concepts of ecosystem structure and function provide a potentially useful framework for the successful maintenance and restoration of wetland ecosystem services. The paradigm that degradation of structure results in reduced function has been well demonstrated for wetland ecosystem services such as the provision of habitat or flood storage. However, this paradigm has not been well tested for biogeochemical wetland functions such as denitrification. To be able to relate descriptions of structure that would be relevant to denitrification, we measured a number of descriptors of biogeochemical structure of shallow groundwater in a case study of three good condition and three poor condition headwater riparian wetlands in central Pennsylvania. In each wetland, twenty shallow groundwater piezometers were located in a 400m2 plot. Water samples were gathered in May, early October, and late October of 2012 and analyzed for pH, temperature, DO, DOC, nitrate, and total nitrogen. _These variables, known to be important for denitrification, were used in a cluster analysis to identify distinct functional habitats for denitrification. These functional habitats were then compared with denitrification model results using the denitrification subroutine of the DeNitrification-DeComposition (DNDC) model, and also with potential denitrification rates determined at the wetlands using the push-pull method.

Contact

  Christopher Fernandez
  cwf123@psu.edu