Since human activities have an unprecedented role in increasing atmospheric concentrations of greenhouse gases (GHG) and in the resulting global temperature rise, different mitigation activities of GHG emissions are needed. The mining industry is associated with major environmental issues, including GHG emissions and the establishment of tailings sites (TS), which induce important land-use change. In order to bring these sites closer to their initial state, the revegetation of TS should then promote reforestation instead of using herbaceous plants.
The aim of this study is to build specific growth and yield curves and determine the long-term carbon storage of two active and reforested TS, Niobec (Saint-Honoré, QC, Canada) and ArcelorMittal (Fermont, QC, Canada), and one abandoned TS, the Lac Jeannine mine (Gagnon, QC, Canada). The main objective of this study is to determine if the recognized growth and yield tables in QC are valid on these mine sites, to enable the long-term prediction of tree growth and carbon stocking on reforested TS. As the ArcelorMittal mine is beyond the northern limit of allowable cuts, its surroundings were studied to determine the expected local growth signal. The three TS are non-acid, amended with different organic matter sources and reforested. The growth and yield of planted Pinus banksiana and Picea mariana were established by stem analyzes with trees from the three TS. The CBM-CFS3 model was used to determine the ecosystems rate of carbon sequestration based on these built-in yield curves.
Results/Conclusions
Preliminary results indicate that trees planted on the ArcelorMittal TS have a particular growth rate, especially because of the wind factor. As the mature trees harvested in the immediate environment of the mine were found typical of an even-aged stand, it is hardly practical to draw conclusions on their potential as proxy for long term growth and yield of plantations on this TS. It seems therefore necessary to find more representative proxy sites to establish tree growth and yield on a TS located beyond the allowable cuts zone. Trees planted in the early 1990s on the abandoned Lac Jeanine TS show promising potential in this regard, this site being located nearby the ArcelorMittal site, with comparable climate and tailings characteristics.
The poster will also provide the growth and yield results from a 30 year-old Pinus banksiana plantation at the Niobec TS, and its potential as a longer term predictor of growth and carbon sequestration capacity on Niobec’s new TS development.