FORT MACLEOD, Alta. – A University of Alberta student hopes to prove native grasses can be restored one plug at a time.
Doctoral candidate Steven Tannas is working on four field study sites in southern Alberta in an effort to grow rough fescue and other native plants on well sites after the ground has been disturbed and invaded by tame species.
“Seed establishment of rough fescue has been very poor historically,” Tannas said at the Oldman Watershed Council meeting in Fort Macleod, Alta., Jan. 22.
“I don’t know if we have had instances where we successfully restored rough fescue through seeding.”
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Some of his work with transplanted grasses and greenhouse grown plant plugs is supported by Compton Petroleum Corp., a natural gas company working mostly in the eastern slopes of the Rocky Mountains.
Compton’s Kurtis Averill said landowners often complain about the destruction of native grasslands after wells are drilled and pipeline trenches are dug.
He admits restoration of native plants to well sites has not been successful.
Averill said the company is learning more about rangeland health by consulting with landowners and avoiding pristine grasslands. Before entering an area, it considers whether minimal disturbance might take place in winter or during dormant growing periods.
“We have a long way to go but we are seeing some successes,” Averill said.
The foothills represent one of the most diverse plant ecosystems in Alberta.
The region has seen invasions of tame species such as Kentucky bluegrass, bromegrasses and timothy hay. But these plants do not provide enough nutrition to livestock in winter and do not survive droughts. That’s why fescue, which has adapted to the region, must be preserved.
“What we have is reduced biodiversity and a less economical use for agriculture,” Tannas said.
Rough fescue is the dominant grass in the area and may set seeds every four or five years when conditions permit. Some plant stands could be centuries old.
However, disturbance, tillage and mowing can drive out rough fescue and allow invader species to take hold. Low moisture and poor soil fertility also affect the plants’ ability to take hold.
Seedlings can be difficult to establish because the plants’ poorly developed root systems are too small to take up adequate moisture and nutrients during a drought.
Rough fescue matures in about four years. The plants may fail if there is a nitrogen imbalance, too much or too little water, or not enough ground cover from litter.
Researchers have tried high seeding rates, transplanting mature sod and putting in plant plugs started in greenhouses, a practice that has been successful in California.
The survival rate for transplanted plants was 55 percent and nearly 80 percent for plugs.
“Some of the greenhouse plugs were actually growing at a way faster rate than these mature cuttings that we thought would have a bigger root mass,” Tannas said.
He added sawdust when planting the plugs, which seemed to provide needed litter on the soil surface, as well as nitrogen.
However, replacing native plants with plugs costs about $2 each. The price may decline if the restoration projects go to seed.
Plug survival rates at a site near Carbon, Alta., are expected to be examined this spring.
After that, researchers will have to explore whether the process can be replicated on a large scale to help repair grasslands that were invaded or degraded.
