In Alberta, to release liability of an upstream oil and gas site on forested lands it must meet the criteria laid out in the 2010 Reclamation Criteria for Wellsite’s and Associated Facilities for Forested Lands (ESRD, 2013). This criterion lists requirements for landscape, soil and vegetation parameters that will obtain equivalent land capability. These guidelines do not cover oil sands areas due to the complete removal of the upper 30m requiring complete reconstruction of the environment, versus reclamation or restoration.
The main challenges in meeting the aforementioned criterion is the vegetation requirements, specifically the required woody stem count and percent cover of native herbaceous species. Planting of woody species is a successful strategy for achieving sufficient woody stem count, however increasing herbaceous cover is difficult due to the lack of readily available seed in large quantities and the lack of understanding of effective seeding practices (Schoonmaker et al., 2014). Finding a more viable option for achieving native herbaceous species cover has the potential to reduce costs by providing a much higher success rate for establishment and by reducing the number of years it takes for certification to take place. Additionally, if the hitchhiker planting method is successful it could be a cost-saving alternative for revegetation of the massive area of land already disturbed by oil sands operations.
The objective of this section of the study was to determine the effects of companion planting a native herbaceous species with a white spruce seedling. The previous research demonstrated that viable stocktypes were able to be produced, and that they could successfully establish on sites with varying soil and landscape characteristics. Measuring shoot and root characteristics, as well as vegetation composition, allowed for an assessment of the ecosystem similar to that done during detailed site assessments for reclamation certification.
Research questions to be addressed within this project:
What is the effect of stock type on the growth of the native forb species, while co-grown with spruce?
Does the established forb impact vegetation dynamics (reduce competition) of other undesirable species in the immediate vicinity of the white spruce seedling?
Can we produce mixed-container stock of white spruce that is comparable or better than singly produced white spruce seedlings?
Hypothesis:
The native forb species will be thriving after two growing seasons in the treatments where it was sown in early, and cover will be reduced in later sow dates due to increased competition from the spruce.
Establishment of the forb will reduce the number of invasive species present in the immediate vicinity of the white spruce seedling, primarily due to physical occupation of space.
The optimal stock type for growth of both the white spruce seedling and native forb, based on the greenhouse trial (10 week, 615A) will demonstrate root and shoot characteristics after two growing seasons that are comparable to the control stock type. The earlier sow dates and smaller stock size will result in reduced spruce growth due to competition.