Microsites play a very important role in biodiversity, naturally occurring seedling regeneration, and tree canopy establishment in natural forests. Microsite variability and availability in forests can provide a range of different biotic and abiotic growing conditions for plants to establish in. The changes of the growing conditions in microsites is due to variation in microtopography, soil types, pre-existing vegetation communities, and disturbance regimes, among other factors (Zenner et al. 2007). Understanding the factors influencing the forest understory establishment is a crucial component to forest restoration, because the understory is the foundational component of functioning forest ecosystems. |
The mining of oil sands entails severe disturbances of natural forests. Reclaiming these disturbed sites and returning them back to a natural state can be challenging since it requires building the entire site from scratch. This includes placing cover soils and planting seedlings, all while trying to restore the native vegetation and natural functions of forest ecosystems. Current land reclamation sites are constructed flat with not much microtopography variability, which could be restricting to potential niche differentiation, the establishment of native vegetation communities, and the creation of optimal growing conditions for planted seedlings. Furthermore, salvaged forest floor materials used for forest land reclamation contains plant propagules that could support a more diverse native vegetation understory. However, often these native species are not maintained in the harsh growing conditions of reclamation sites, and end up being replaced by ruderal, competitive, and often non-native species which can dominate sites for many years before a tree canopy can develop. Previous studies have shown that introducing different site construction practices that increase the variability of microtopography can help with the establishment of more native species originating in the soil bank, as well as reduce the competition of ruderal species (Melnik et al. 2017). |