Tim Vinge often talks about unintended consequences.
As a landscape ecologist with Alberta Environment and Sustainable Resource Development (ESRD), he is presently participating in a study that was bound to experience one or two.
The study, which began on a patch of wetland at the Evergreen Centre for Resource Excellence and Innovation in Grande Prairie, Alberta in the winter of 2011, revolves around determining the viability of reforesting wet sites that have been disturbed by oil and gas industry activity by planting black spruce saplings at those locations during the winter months.
“It’s too hard to do that in the summertime when the muskeg’s not frozen,” Vinge said of the decision to try planting the trees in the winter.
“A lot of our wetland – our bog and fen sites – are essentially inaccessible on the ground in the summer because they’re just too wet,” added Jeremy Reid, an environmental specialist with Nexen and project manager for the Land Stewardship Working Group of the Oil Sands Leadership Initiative (OSLI), the industry group participating in the study.
“Logistically, it’s extremely hard to access them,” he said.
Energy sector companies such as Nexen have other reasons for conducting this research, not the least of which is simply that they want to help disturbed sites return to their natural state.
“The regulation around reclamation has been to let it naturally regenerate,” said Reid.
“By planting trees and by using these sorts of techniques like winter planting, we’re looking to accelerate the reclamation or re-vegetation of these areas,” he continued.
“That will result in these clearings having less negative impact to biodiversity. Because, sometimes, if you leave a disturbance for a long period time, then you’ve affected habitat and you’ve affected biodiversity, and it may not be reversible.
“We’re looking at rehabilitating these disturbances as quickly as possible to have as little negative impact to biodiversity.”
The reforestation technique being tested involves a process known as mounding, whereby an excavator is used to dig a hole in the only partially frozen ground and flip that pile of soil over to create an elevated site in which to plant the trees.
“So, you have a sandwich underneath it of organic matter,” added Vinge.
“And the reason we’re doing all of that is because there’s a desire to do restoration work of linear features, which would include seismic lines, but also probably pipelines and maybe even well sites that are located on organic material,” he continued, drawing attention to the difference between mineral soils consisting of sand, silt and clay and organic soils such as muskeg.
“And do that all in one pass in the wintertime. So, rather than mounding it in the winter and then flying a bunch of planters out there in the summer, we decided to see if we could do it in concert.”
The saplings performed fairly well after their first dose of winter in 2011, despite one of Vinge’s unintended consequences.
“Planting the trees in the wintertime, they survive just fine,” he said, noting that the researchers achieved a nearly 100 per cent success rate.
“And we found that planting them deeper gave us somewhat better results than planting them shallow,” he continued.
Temperatures that fell below twenty degrees Celsius were an issue, particularly during an unanticipated cold snap late in the season.
“We lost a few of the lateral buds,” said Vinge.
“But the bigger buds seemed to survive quite well,” he added. “So, if the buds were too small, they got frozen. And if they were bigger, they didn’t. But we didn’t baby them.”
Vinge remarked that trees usually survive the winter thanks to a covering of snow.
“Potentially, if we covered them with snow as soon as we planted them, the snow would have moderated the temperature somewhat,” he suggested.
“We didn’t get a lot of snow back then.”
Vinge explained that the surviving saplings lived normally through the summer and fall, but experienced another of his unintended consequences this past winter, when temperatures in Grande Prairie climbed as high as ten degrees Celsius around late January and early February.
“I think black spruce is probably the worst for this, but it’s called red belt,” said Vinge, describing that unintended consequence.
“Red belting or desiccation,” he continued. “And what happens is the trees get exposed to some hot weather. And because they’re grown in a nursery, the needles… don’t have a lot of cuticle waxes on them yet… They’re still a little pampered from the nursery.
“And so along comes this nice weather … and the trees think it’s time to start growing. So, they open up their stomata and they release their moisture, because they’re going to start growing.”
The problem is that the roots are still stuck in the frozen ground, unable to draw the water from the soil necessary to replace the moisture that has been released from the needles.
“So, what happens is the needles turn red and they die,” said Vinge.
“This happens to trees everywhere,” he explained. “People were saying in Grande Prairie that even their larger trees got red belted because they got fooled into thinking that it’s time to grow. So, as the climate gets a little hotter or we get less snow, this becomes a real problem with first year plantations.”
The saplings on the north side of the experimental plot suffered the most from the red belting because they received direct sunlight.
“But the ones on the south side, where there’s a little more shade and snow, and it took the snow a little longer to melt, were okay,” said Vinge. “Perfectly okay. So, the winter planting didn’t have anything to do with the red belting. This phenomenon does occur [regardless].
“But it does point out a serious problem,” he continued. “Because it doesn’t matter where you put the trees, in a cut block or in a pipeline or in an oil site, if you don’t have any snow, then it becomes a serious problem, especially if you elevate them on a mound. Now they’re sticking up there, right?”
Judging by the response from both Vinge and Reid, this setback has only inspired further experimentation.
“Something we’d like to try out is different tree stocks,” said Reid. “Different sizes of trees. And maybe change the way they’re grown initially in the greenhouse. And investigate changes we can make at that stage of the process to essentially get a hardier tree in the bush to plant.
“We need as hardy a tree as possible to plant in the winter,” he added, suggesting that trees typically cultivated in a greenhouse aren’t actually well suited to winter planting because it isn’t a technique that has been used in the past.
“We’d like to follow up now with these trees,” said Vinge. “The ones that didn’t get hit – red belted – are growing just fine. They’re growing great.
“We want to do what’s called a stock trial,” he continued, echoing Reid. “So, we want to take some different trees grown in a nursery and expose them to these conditions artificially and see how they tough [it] out. So, I’m looking for some partners that would be interested in looking at how to grow a quite a bit more drought tolerant seedling.”
Vinge also plans to experiment with different ways of building the mounds.
“Whether we would have planted the trees last summer or put them in this spring, they have the potential to get red belted, unless they get a good snow cover on them,” he said. “That’s really important.
“So, what do we learn from that? We decided what we needed to do was to make the mounds somewhat lower so they’re not so high. We decided that we maybe need to make little bit of a divot in one side of the mound so that we can put our trees a little bit lower, so they’ve got the mound protecting them. Kind of like a little bit of natural shade.”
There is also potential for using different species of trees, although one possible candidate, white spruce, does tend to suffer from red belting as readily as black spruce.
“Pine, not so bad,” said Vinge.
“Maybe what we need to do is we need to hedge our bets and plant maybe some tamarack, which loses its needles, and black spruce,” he added.
Tamarack tend to occur in fens, where the water is moving, while black spruce tend to occur in bogs, where the water is stagnant. Both types of wetlands are common in areas of oil and gas industry activity in the province.
The possible solutions to the unintended consequences have seemingly given Vinge confidence in the inevitable success of the project.
“We can look at this and go, ‘This is a failure.’ It’s not a failure,” he said. “We’ve learned some really important things about snow and trees and temperature.”
Reid appears confident, too.
“We’re very happy with how the trial went in Grande Prairie,” he said. “And we operationalized the technique this past winter. We planted about between 30 and 40 thousand trees with that technique.”
Those trees were planted just southwest of Fort McMurray.
“We have a monitoring program that we’re initiating this summer.”