Monday, April 14, 2008

Willows in a (still) Winter Wonderland

Last year, The Nature Conservancy completed a restoration project on its Flat Ranch Preserve (located 15 miles west of West Yellowstone), to reduce river sediments in the Henry’s Lake Outlet. These sediments clog up rivers and reservoirs, and were recognized as one of the greatest threats to spawning trout in the famous Henry’s Fork. The Conservancy and the Henry’s Fork Foundation took an artificially straightened portion of the Henry’s Lake Outlet and diverted back into its historic, meandering channel. Although “spring has sprung” in parts of Idaho, it’s still a “winter wonderland” at Henry’s Lake—meaning that now is the time to collect willows to stabilize the banks on the protection project. East Idaho conservation manager Chet Work files this report:

The outlet restoration project we completed last year is in need of bank stabilization. Not having water in the creek for the last 60 years has made some of the banks vulnerable to the pressures of moving water. As we bring river flows back to the channel this spring, we will need to begin working on stabilizing the banks with vegetation. Grasses and forbs do pretty well, but their roots are relatively shallow and can be undercut. We need to get woody (deep rooted) vegetation back on the banks and willows are the best!
Willows, like many deciduous plants have the ability to resprout from clippings, segments of branches and stems. Similarly, willows are difficult to regrow from seed so it makes sense to use clippings. Willows are also highly prone to hybridization when grown from seed. Though it is possible to identify individual species of willow, many times we have hybrids that are tough to classify. Because we do not want to introduce new hybrids to our ranch, we go get clippings from the restoration area.

Like all deciduous plants, willows lose their leaves and go "dormant" during the winter. The best success for clipping is to cut a dormant plant and as it wakes up it will re-sprout roots and leaves all at once. Cutting a clipping in the summer will only kill the clipping. So we have to do this before they wake up for the season, hence the need for snowmobiles.

Our goal is 500 new willows. Half of our clippings will go to a a group called Upper Valley Natives to be grown into 5-foot willows in 5-gallon pots. In late summer they will deliver 200 willows (of our exact species) to us and we will dig holes and drop them in. The other 300 are currently in a walk-in freezer, hopefully staying dormant. When the weather heats up and we can get out on the ground we will drill small holes for these clippings in the stream bank using a pressure washer, and will insert them into the holes. The success for these "water jet" plants is much lower than the greenhouse variety, but so is the cost. I hope you can visit Flat Ranch Preserve this season, and see the results of our willow planting and stream restoration efforts. –Chet Work, East Idaho conservation manager

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