New research tracks successes in growing full-sized sagebrush
Recent research by a team from the Quinney College of Natural Resources, in collaboration with Bayer, has begun to develop strategies to improve sagebrush rehabilitation – but it has required outside-the-box thinking.
Perhaps in a fit of justifiable frustration, managers are increasingly using greenhouse-grown sagebrush seedlings to rehabilitate pastures in the western United States — but this kind of transplanting effort can have unreliable results, even with the added cost of feet on the ground to stimulate the young. Plants in the soil. So when managers at Bayer’s Soda Springs Idaho Site, which includes a 2,400-acre working ranch (Fox Hills Ranch), had a slightly strange idea, Eric Thacker and Carrie Veblen of USC’s Wildlands Resources Department were ready to explore.
Worldwide, 10% to 20% of dryland ecosystems are now considered severely degraded, making it essential to find ways to rebuild these complex, slow-growing plant communities. Sagebrush is a foundational type. It provides cover and food for a variety of native birds, animals and insects.
But the small, ephemeral sage seeds do not spread long distances on their own and do not remain viable for long on the ground. When disturbance removes mature plants from large areas of land, reestablishing them requires a living, local source of seed. Scattering hundreds of thousands of sage seeds over multiple seasons often creates only a few plants that are well isolated enough to produce seeds on their own. This leaves wide, vulnerable gaps, where invasive weeds can settle into the home and plunder available resources.
Have they tried planting full-sized wild sagebrush in degraded areas — just as a rosebush or peach tree would in the garden — to serve as a seed source, asked Joe Via, an environmental reclamation specialist at Bayer. Via identified a plot of land where the company’s mining activities were scheduled to expand, and offered up large mountain sagebrush plants (which would have to be removed anyway) to trial planting on an area of land slated for restoration at Fox Hills Ranch.
Liz Bailey, a master’s student at USU who shouldered the brunt of the work on the project, said this approach opened new horizons for sagebrush restoration. The team knew that extracting mature sagebrush plants and moving them to a new area would require an incredibly labor intensive effort. They also realized that this effort would certainly be expensive compared to seeds or sagebrush seedlings – but given the miserable rates of successful establishment typically recorded for these other projects, the costs are still reasonable, especially when counting surviving plants as the measure of success, rather than Try just an acre.
After removing non-native plants from the experimental area and seeding the area with a variety of plant species, the team grew sagebrush in three comparison methods — from seed, from greenhouse seedlings, and by transplanting wild sagebrush plants — and tracked the survival rates of each. Strategy over several years. After the third year, the survival rate of plants grown in the greenhouse was only 14%, while 85% of the cultivated sage survived.
Although other studies have shown better success using plants grown in greenhouses, success rates tend to vary widely depending on local conditions, says Bailey, which is part of the problem.
“This really showed that established wild plants planted with an intact root ball can be used to obtain high rates of early establishment of large mountain sagebrush,” Bailey said. “Although there is still a chance that the taproot will be cut off when digging up mature plants for planting, the remaining roots can remain in contact with the soil and keep the plants alive.”
Harvesting wild plants close to the project site (from about 7 miles away) may have contributed to the higher survival rates, she said. Native plants have the opportunity to develop local adaptations – such as increased drought and frost resistance, specialized growth rates and other competitive advantages over seeds from abroad that are not locally adapted.
The cost per surviving plant also leans in favor of the transplanting strategy, despite the increased effort required, at about half the price of seedlings ($3.68 per mature wild plant alive versus $7.95 per surviving greenhouse seedling).
The team is now tracking how these plants expand their territories, whether mature sagebrush plants will continue to serve as productive seed sources after they are moved, and whether these new plants will survive and thrive.
Bayer shared information and progress with other federal, state, and local management agencies, and held field trips to allow others to see the successes and challenges of the project. Continued monitoring will allow the team to understand the long-term trajectory of the ecosystem in this slow-growing environment, and they will take every year they can to monitor where the sagebrush is growing.
(Tags for translation)Utah State University
