Comparisons of water and peat chemistries of a post-harvested and undisturbed peatland with relevance to restoration

Peat harvesting has altered site water and peat chemistry at the Seba Beach peatland through removal of surface bog peat, moving the site back in the fen-to-bog succession time sequence. The post-harvested site is more similar to a moderate-rich fen in water and peat chemistry than the bog that it was originally. The exposure of fen peat has resulted in significantly higher concentrations for almost all water and peat chemical components compared to the neighboring natural bog. During five years of sampling this study found no significant differences between years in the water and peat chemistry within the natural area. A few significant yearly differences were found in the harvested area water chemistry, while the harvested area peat chemistry had many significant yearly differences. Several patterns were noted in the nitrogen concentrations in the harvested field. First, the harvested site had significantly higher concentrations of aqueous NH4+-N and NO3--N, as well as available NO3-N in the peat, compared to the neighboring natural area. A variety of possible factors, such as increased aeration, high pH values, and low vegetation cover may account for these high nitrogen concentrations. Second, peat nitrogen concentrations seem to be affected by soil moisture. Harvested areas with high soil moisture had high concentrations of available NH4-N and lower available NO3-N concentrations, while drier areas had high concentrations of available NO3-N and lower available NH4-N concentrations. Third, the concentrations of these nutrients in the harvested area did not remain static over the years. In the peat, available NO3-N concentrations were significantly reduced in 1995, and in the well samples, NH4+-N was significantly reduced in 1994 and 1995 compared to earlier years. This research shows that the chemistry of the harvested site has significantly changed from the original bog ecosystem. As the site is more similar to a moderate-rich fen, ombrotrophic bog species are unlikely to thrive on this site.