Biological communities and ecosystem function in restored and natural prairie wetlands / by Lauren Elisa Bortolotti.

Thesis(Ph.D.)--University of Alberta.

Includes bibliographical references.

quantified greenhouse gas (GHG) fluxes from the open water of three restored and natural prairie wetlands and used both CO2 fluxes and net ecosystem production (NEP; measured using the diel oxygen technique) to assess the metabolic status (i.e., net autotrophic or heterotrophic) of prairie wetlands. GHG emissions tended to be high, but variable. The recently restored wetland emitted more CO2 and methane than either the older restored or natural wetland, and only the latter showed extensive CO2 uptake. CO2 supersaturation was a less reliable indicator of wetland metabolic status than NEP, especially at daily timescales, owing to the confounding influence of geochemical processes on CO2 concentrations.
I measured ecosystem metabolism, including NEP, gross primary production (GPP), and ecosystem respiration (ER) in three restored and natural prairie wetlands and identified the drivers of these rates. Photosynthetically active radiation, temperature, proxies of water column stratification, and SAV abundance were the main drivers of metabolism within wetlands. However, the recently restored wetland differed from the other sites in that chlorophyll a (chl a) and TP were also drivers of GPP and NEP. Among-wetland differences in NEP rates were determined by a combination of wetland state (i.e., clear water or turbid) and the degree to which emergent vegetation subsidized ER. GPP and ER were highest in the older restored wetland followed by the natural and recently restored wetlands. The GPP gradient across sites was explained by the abundance of SAV whereas the ER gradient by the abundance of substrates for microbial respiration (dissolved organic carbon, sediment OC).
To date, this body of research represents one of the most comprehensive examinations of the recovery of biological communities after wetland restoration in the Canadian Prairie Pothole Region and is the first to look at ecosystem metabolism in this system. My work suggests thatoplankton communities showed little relationship to restoration state, but taxonomic composition of macroinvertebrate and SAV communities were different in recently restored wetlands. The consistent resemblance of older restored wetlands to natural wetlands suggests that recovery of the abiotic environment and many biological communities is possible within ~10 years. years of restoration, a result with direct implications for management.
I quantified greenhouse gas (GHG) fluxes from the open water of three restored and natural prairie wetlands and used both CO2 fluxes and net ecosystem production (NEP; measured using the diel oxygen technique) to assess the metabolic status (i.e., net autotrophic or heterotrophic) of prairie wetlands. GHG emissions tended to be high, but variable. The recently restored wetland emitted more CO2 and methane than either the older restored or natural wetland, and only the latter showed extensive CO2 uptake. CO2 supersaturation was a less reliable indicator of wetland metabolic status than NEP, especially at daily timescales, owing to the confounding influence of geochemical processes on CO2 concentrations.
I measured ecosystem metabolism, including NEP, gross primary production (GPP), and ecosystem respiration (ER) in three restored and natural prairie wetlands and identified the drivers of these rates. Photosynthetically active radiation, temperature, proxies of water column stratification, and SAV abundance were the main drivers of metabolism within wetlands. However, the recently restored wetland differed from the other sites in that chlorophyll a (chl a) and TP were also drivers of GPP and NEP. Among-wetland differences in NEP rates were determined by a combination of wetland state (i.e., clear water or turbid) and the degree to which emergent vegetation subsidized ER. GPP and ER were highest in the older restored wetland followed by the natural and recently restored wetlands. The GPP gradient across sites was explained by the abundance of SAV whereas the ER gradient by the abundance of substrates for microbial respiration (dissolved organic carbon, sediment OC).
To date, this body of research represents one of the most comprehensive examinations of the recovery of biological communities after wetland restoration in the Canadian Prairie Pothole Region and is the first to look at ecosystem metabolism in this system. My work suggests that many attributes of prairie wetlands recover after restoration, though more work is needed to better characterize the effects of restoration on ecosystem metabolism and to understand how broadly applicable these findings are to the rest of the Prairie Pothole Region.