How mounds are made matters: implications for seismic line restoration in peatlands
Presenter: Kimberly Kleinke, University of Waterloo
The boreal forest of western Canada is fragmented by seismic lines created for oil and gas exploration. These linear disturbances have large-scale consequences for wildlife and other elements of ecosystem function. Currently, the most common method for seismic line restoration is mechanical mounding. Mechanical mounding uses a backhoe to dig and flip the peat to create mounds with the purpose of providing drier microsites for tree growth. In uplands, mechanical mounding has shown to improve tree growth and survival. In peatlands, however, this method of mounding also changes important peatland functions such as hydrology and ground-layer plant diversity. New mounding methods that keep the peat profile intact and preserve existing vegetation may improve substrate quality and peatland restoration success. To compare the effects of different mounding methods on substrate quality, we collected peat cores from two sites in Alberta. These were analyzed for C/N ratios, δ13C, δ15N, and Fourier transform infrared (FTIR) spectroscopy humification indices. Both sites represent several seismic lines crossing poor fens. One site was treated with mechanical mounding, while the other was treated with two new mounding methods that keep the peat profile intact. Mechanical mounding was found to create mounds with high degrees of decomposition, indicating lower substrate quality. There was no statistical difference in measured substrate properties between the new mounding methods and reference natural hummocks. By preserving the peat profile, new mounding methods may improve seismic line restoration by maintaining natural substrate quality.