COTTONWOOD SURVEY AND RESTORATION
SUMMARY
The Elk River Alliance is running a multi-year landscape-level restoration program to improve riparian areas impacted by agriculture and development. Cottonwoods are beautiful deciduous trees native to North America, well known for releasing fluffy seeds that fall like snowflakes in the early summer. They provide shade and food for animals, stabilise river banks, and slow down floodwaters. Unfortunately, land-use such as urban development, agriculture, and infrastructure often competes for space with cottonwood forests. To address the loss of floodplain forest, the Elk River Alliance is running an ecosystem-scale cottonwood assessment and restoration project in the Elk Valley.
GOAL
Improve riparian habitat for fish and wildlife, decrease streambank erosion, and mitigate downstream flood risks.
OBJECTIVE
Plant 20,000 cottonwood trees and native seedlings by 2027.
METHODOLOGY
STEP 1
Site Assessment
COMPLETE
Conduct a valley-wide assessment of cottonwood extent and riparian zone degradation to determine areas in most need of restoration. Conduct site visits to evaluate efficacy of restoration efforts.
STEP 2
Land Securement
COMPLETE
Collaborating with landowners and partner organisations to put in place agreements for restoration efforts. Once sites are chosen, site-specific restoration prescriptions are developed to guide restoration efforts and ensure maximum success.
STEP 3
Fencing & Planting
IN PROGRESS
Installation of 100x50m fence plots to prevent browsing by herbivores. Engaging volunteers to help with livestake collection, planting, and maintenance.
STEP 4
Monitoring & Maintenance
2026-2027
Monitoring of plants to determine survivorship and growth rates. Maintaining fencing to ensure it keeps out herbivores. After 10-20 years fencing will be removed.
PROJECT SITES
Big Ranch
The Nature Trust of BC acquired the 483.9 hectare Big Ranch property between 1990-2003 with the goal of conserving critical elk habitat in the Elk Valley. To accomplish the mutual goals of habitat improvement, ERA and NTBC are working together to develop restoration plans.
Big Ranch Restoration Project Funders: Environment and Climate Change Canada, Columbia Basin Trust, Habitat Conservation Trust Foundation, Fortis BC, TD Friends of the Environment Foundation
Elk Valley Lodge
The Elk Valley Lodge is owned by a private property owner who gave ERA permission to conduct restoration work with an aim to decrease erosion rates, and therefore property loss.
Elk Valley Lodge Restoration Project Funders: Columbia Basin Trust, Habitat Conservation Trust Foundation, Fortis BC, TD Friends of the Environment Foundation
Hosmer Gravel Pit
Since 2017, ERA and the Nature Conservancy Canada have collaborated to restore this gravel pit into a naturalised wetland. Work to date includes planting cottonwoods and native species and installing a grazer exclusion plot. This site will be considered for more restoration work after the remaining sites are complete.
Morrissey Meadows
The Morrissey Meadows Conservation Area was acquired by the Nature Conservancy Canada in 2018 with the goal of improving wildlife movement corridors in the Elk Valley. Adjacent to Hwy 3, this area has potential to be a vital passage for terrestrial species. NCC has conducted extensive restoration work, including the construction of a backchannel for fish and wildlife, and the planting of riparian trees to improve streambank stability. ERA is partnering with NCC to construct more fencing and plant more riparian vegetation.
Morrissey Meadows Project Funders: Columbia Basin Trust, Habitat Conservation Trust Foundation, Fortis BC, TD Friends of the Environment Foundation
(click image to expand)
APPROACH
LIVESTAKING METHODOLOGY
Livestaking is a method of re-planting cuttings from native, resilient vegetation into degraded or eroded areas. Livestakes ~6ft in height are cut from existing groves and inserted 4-6ft into the ground, ensuring the roots reach the water table. As these live stakes take root and grow, they contribute to the restoration of soil structure, prevent erosion, and enhance biodiversity. This method is particularly effective in riparian zones, wetlands, and degraded lands, where it acts as a cost-effective and environmentally friendly solution. ERA plans to monitor livestake survival and determine restoration success.
Livestake planting will be partially completed using a “waterjet stinger”, which uses high-pressure water to dig into soft soils. This is not only a fast way of creating holes for planting, but has the added benefit of inundating the soil with water, which spurs on initial root development.
GRAZER EXCLUSION FENCING
Grazing by herbivores, such as elk, deer, and moose, is a common cause of livestake establishment failure. Grazers will eat plants before they are mature enough to withstand herbivory, thereby negating restoration efforts. To improve the long-term outcomes of restoration work, ERA is installing 100×50 m grazer exclusion plots. After trees are mature (in 15-20 years) the fencing will be removed so wildlife can enjoy the newly restored area.
BACKGROUND INFORMATION
WHY COTTONWOODS?
Black cottonwoods (Populus trichocarpa) are a native species of deciduous tree that naturally thrive in moist soils around wetlands and riparian zones. They are some of the first saplings to dominate riparian zones after flood events or as the stream bank naturally recedes.
In the Elk Valley, many cottonwood forests have been removed to develop agricultural pasture fields for ranching, and so many ecological benefits of cottonwoods have been lost.
Cottonwoods are a relatively hardy species, and can be replanted by taking “live-stake” cuttings and planting them in the ground. This makes them a perfect tree for restoration efforts.
HABITAT IMPROVEMENT
Cottonwood branches form a dense canopy that provides shade for wildlife during the summer heat. The understory brush of cottonwood stands is a perfect habitat for elk, bears, birds, and many other terrestrial animals. Importantly, canopy overhanging creeks and rivers can decrease water temperatures which is vital for fish like trout.
ECOSYSTEM BENEFITS OF RIPARIAN VEGETATION
1. Food and Habitat of Fish and Wildlife
Terrestrial wildlife, including grizzly bears, elk, moose, eagles, and osprey, use cottonwood trees as a habitat. Cottonwood leaves and understory plant growth provide animals with food. Large trees that fall into the stream create large woody debris, which is a key habitat for fish like the Westslope cutthroat trout.
2. Shaded Refuge from the Summer Heat
With climate change, summer temperature extremes are only expected to get hotter. Ensuring fish and wildlife have plenty of shaded areas is essential to their survival. For aquatic environments, shade can decrease water temperatures by 3-5C, which is a critical difference for cold-water fish who experience signs of heat stress above 20C.
3. Aquatic Nutrient Input
Leaf litter and fallen branches form the basis of nutrient cycles, which support entire foodwebs.
4. Streambank Stabilisation Decreases Water Sediment
Tree roots reinforce stream banks, decreasing erosion rates; removing trees therefore increases aquatic sediment levels. Sediment in water is natural, but excess sediment can be a stressor for aquatic animals. Particles clog the gills of fish and insects, making it harder to breathe. Additionally, sediment fills in spaces between rocks, removing a vital habitat for benthic invertebrates and young fish.
STREAMBANK STABILISATION
Plant roots act like rebar, holding the soil in place and slowing erosion rates. In this way, riparian vegetation protects properties from being lost to the river.
SHALLOW GRASSES DON’T PROTECT STREAMBANKS
Agricultural fields have grasses with shallow root systems, which are prone to being undercut by fast currents. The roots of riparian plants, including trees, shrubs, and grasses, penetrate and bind the soil, creating a cohesive matrix that helps prevent erosion. By restoring cottonwood trees in these areas, we protect property from being washed into the river.
In the image below, you can see a former agricultural field in Sparwood. During the flood of 2013, a large portion of this area was washed into the stream.
FLOOD MITIGATION
Riparian vegetation can decrease flood impacts by absorbing the energy of flood water.
In floodplains, where high waters frequently exceed the riverbanks, cottonwood trees and the understory shrubs decrease water velocity and “hold on” to floodwater. A healthy riparian ecosystem includes backchannels and wetlands full of riparian plants. These areas provide space for water during flooding events, decreasing water velocity and therefore downstream flood damage. In the image below you can see how much water backchannels and wetlands were holding during the 2013 flood.
GET INVOLVED
Sign up to volunteer!
Join us in planting plants and restoring the ecosystem.
Please note, restoration days often consist of hard manual labour outdoors.
PARTNERS AND FUNDERS
FUNDERS
PARTNERS
