by Ann Lezberg, Technical Advisor, Wildlands Restoration Volunteers and John Giordanengo, Projects Director, Wildlands Restoration Volunteers

(Continued from the green line, Volume 19, Number 2, summer, 2008)


Most of the following definitions are provided by the USDA-NRCS, Plant Materials Center, Aberdeen, ID. This is not a comprehensive list of willow or riparian-related terms, but are common terms found in the literature related to willows, riparian restoration, stream ecology, etc.
Aggradation: To fill and raise the level of the bed of a stream by deposition of sediment.
Alluvial: Deposited by running water.
Bankfull Discharge: The discharge corresponding to the stage at which the natural channel is full. This flow typically has a recurrence interval of 1.5 to 2 years.
Best Management Practices: A practice used to reduce the impacts from a particular land use.
Bioengineering: The integration of living woody and herbaceous materials along with organic and inorganic materials to increase the strength and structure of soil.
Buffer: A vegetated area of grass, shrubs, or trees designed to capture and filter runoff from surrounding land uses.
Canopy: The overhead branches and leaves of vegetation.
Capillary Fringe: The distance water is wicked upwards above the water table by capillary action in the soil.
Coir: A woven mat of coconut fibers used for various soil erosion control applications; Biodegrades after a period of a few years.
Degradation: The process of by which stream beds lower in elevation; opposite of aggradation.
Deposition: The settlement of material out of water.
Geomorphology: The geologic study of the evolution and configuration of land forms.
Habitat: The area or environment in which an organism lives.
Incised Channel: A stream that has cut its channel into the bed of a valley.
Reach: A short length of stream that has similar physical and biological characteristics.
Riparian Area: A riparian area is an ecosystem situated between aquatic and upland environments and is characterized by greater soil moisture than adjacent upland areas. Riparian areas are periodically influenced by flooding.
Root to Shoot Ratio: the dry weight of root biomass divided by the dry weight of shoot biomass. A plant that has a greater biomass of leaves and stems, compared to the biomass of its roots, would have a low root to shoot ratio. A low root to shoot ratio is considered an unhealthy condition for many plants.
Scour: Erosive action of flowing water in a stream.
Substrate: The mineral and organic material that from the bed of a stream.
Thalweg: A longitudinal line that follows the deepest part of the channel of a stream.
Watershed: An area of land that drains into a particular river or stream, usually divided by topography.
Wattle: A sausage-like bundle of plant cuttings used to stabilize stream banks and other slopes.


Auble, G.T., Roelle, J.E., and A. Timberman. 2006. Riparian willow restoration at Arapaho National Wildlife Refuge. The green line online 17:4.
Bentrup, G. and Hoag, J.C. 1998. The Practical Streambank Bioengineering Guide. USDA-Natural Resources Conservation Service Plant Materials Center. P.O. Box 296. Aberdeen, ID 83210.             (208) 397-4133      .
Gage, E.A., and D. J. Cooper. 2004. Controls on willow cutting survival in a montane riparian area. Journal of Range Management 57:597-600.
Hoag, J.C. 2007. How to plant willows and cottonwoods for riparian restoration. TN (Technical Note) Plant Materials No. 23. USDA Conservation Services, Boise, Idaho. 22 pp.
Schaff, S.D., Pezeshki, S.R., Shields, F.D., Jr . 2002. Effects of pre-planting soaking on growth and survival of black willow cuttings. Restoration Ecology 10:267-274.
Walter, J., Hughs, D., and D. Moore. 2005. Streambank revegetation and protection: a guide for Alaska (step-by-step fliers).
Zierke, M. 1994. Riparian/ Wetland Project Information Series No. 5: Collection, establishment and evaluation of unrooted woody cuttings to obtain performance tested ecotypes of native willows and cottonwoods. United States Department of Agriculture – Natural Resources Conservation Service, Plant Materials Center, Aberdeen, ID.


WRV is a 501(c)(3) tax exempt organization whose mission is “to foster a community spirit of shared responsibility for the stewardship and restoration of public lands in Northern Colorado, and beyond.”
Our work began in 1999, when about 20 volunteers planted willows to improve wetland habitat around a pond in Boulder County. As of May 2008, WRV has completed 144 stewardship projects, contributing over 97,000 volunteer hours, valued at over $1,700,000 toward the care and restoration of Colorado public lands.
We restore streams and wetlands, build or maintain trails, obliterate old roads, restore areas burned by wildfire, remove invasive weeds, collect native seeds, and much more. We work from the prairie up to high alpine country.
The greatest impact of our work reaches beyond the thousands of hours of volunteer labor on the ground. WRV provides skills, education, tools, and a vision of hope that catalyzes people to fall in love with wild places and realize that they can work together to restore those places and make a real difference in the world.

Colorado Riparian Association