South-facing slope |
East-facing slopeFor the vegetation assessment, Permutational analysis of variance (PERMANOVA) statistical tests were performed (alpha=0.05). The PERMANOVA test was chosen because the vegetation data does not usually have a normal data distribution and has many dependant variables. On the south slope, both the hilled and ridged treatments were significantly different from the control treatment in terms of vegetation cover. This suggests that microtopography could have an effect on the vegetation community in restoration sites that have stressed growing conditions such as the south-facing slope. |
South-facing slope |
East-facing slope |
Figures 14 and 15 explain the average height of all planted species per microtopographical treatment in 2018 on the south and east slopes, respectively.
On the south slope, both aspen and jack pine responded significantly to a change in microtopography in the treatments. White spruce did not have a treatment effect. This can explain the role of the increase of microtopography. Trembling aspen is a taller species compared to jack pine and white spruce because it is an earlier regeneration species and a taller species in general in the early establishment years. This growth response could be due to better growing conditions in the treatments with a high variability of microsites. |
This could also be explained by the hilled and ridged treatment having reduced competition with ruderal species, and having more bare ground than the control treatment (see ordination plots above).
On the east slope, there was no microtopography treatment effect for any of the planted species. This could be explained by the trees being planted one year later than the south slope, and the planted trees requiring an establishing period. Another probable cause could be due to the site's milder conditions compared to the south slope. Since the south slope is a very stressed site due to the amount of solar energy it receives, creating microsites can be beneficial to introduce relief at a larger scale. |