Ensuring reclaimed land matches the boreal landscape

vegetation trends in reclaimed areas in the oil sands

Every year, Syncrude reclaims many hectares of land previously used to support its mining operations. So much so, that more than 4,700 hundred hectares have now been returned back to a productive state.

Much of this land is now home to the wide variety of plants and animals you would expect to see in the region’s natural undisturbed landscape. How do we know this? Through research that describes the plant communities on its reclaimed land and their patterns of change over time.

“The study shows that reclaimed sites are demonstrating promising and accelerating patterns of convergence,” says Craig Farnden, Syncrude’s revegetation research specialist. “This type of monitoring is really valuable for informing future improvements to reclamation practices and policies.”

The study analyzed data from as many as 39 years of vegetation monitoring, beginning with Gateway Hill, Syncrude’s first fully reclaimed site which was planted in 1983. The study’s intent is to evaluate the degree to which species compositions are converging toward those typical of comparable growing sites on the surrounding un-mined landscape.

While it’s not the only metric of reclamation success, it is an important one. Particularly how understory plant communities develop as trees on reclaimed sites grow and expand their crowns. Reduced light levels, increased demands on water and nutrients, and dampening of micro-climatic extremes such as frost all have effects on the understory growing environment.

These effects shift the competitive balance in the understory away from early invading species that are favoured by open canopy conditions to those species that are better adapted to competing for resources under a closed forest canopy. The study shows a relatively slow start to the appearance of “target” species—the 193 native Boreal species observed in the report for natural reference plots. So far, 113 (or 58 per cent) of those target species have been detected on Syncrude’s reclaimed lands. 

For the oldest reclamation plots established in the 1980s, there is an initial lag of as many as 25 years, but this lag is reduced over subsequent decades. Some newer reclaimed locations already have caught up to their earlier counterparts, and have target species richness similar to that found on natural sites.
Craig says that, based on the data, the outlook is positive for its reclaimed sites to reach convergence. 

“This is because our reclamation practices have evolved over time. For example, we no longer apply an intensive agronomic approach to our reclamation. Instead, we’ve changed to practices which better conserve plant propagules in reclamation soils and better facilitate native species immigration. Our practices are setting the stage for nature to do what it does. Through this work we are meeting the expectations that neighbours and regulators place on Syncrude to do it right.”

Interested in other stories like these? Check out
•    Eyes on the sky
•    The beauty beneath the fen
•    A vision for former mine sites

Be in the know! Sign up for COSIA innovation news.