by David Harrison
What do aspen have to do with restoring wild salmon? More than you might think. I found out while visiting The Nature Conservancy’s Dunstan Homestead Preserve.
I arrived at the preserve early one May morning, greeted by a wonderful contrast of spring colors. The yellow-green of the floodplain grasses, to the dark green of the pines and deep blue of the sky. The river was swollen with recent rainfall and snowmelt.
Along the banks, Dunstan caretaker Jerry Ebeltoft shared the Conservancy’s efforts here with my group: work to restore four and a half river miles to improve spawning habitat for native fish. Because it has never had hatcheries (ensuring fish are genetically pure), the John Day River is a key resource for recovery of wild salmon in the Columbia Basin.
Named for the Dunstan family who homesteaded the site in 1888, the preserve lies along the Middle Fork of Oregon’s John Day River, providing refuge to spring Chinook salmon and summer steelhead.
A former dairy ranch, the land has undergone a variety of alterations over the years, including construction of a rail line across it. These changes altered water flow in the river and on its floodplain, negatively impacting the wild fish that are born and bred — and that return to reproduce — here.
Since acquiring the property in 1990, Conservancy ecologists have been busy working to restore healthier conditions to the river and surrounding landscape. Among the first steps was building log bars to provide hiding places for small fish fleeing predators, and to redirect the river’s channel back where it had been prior to settlement.
Other, perhaps more surprising, strategies include work to reestablish trees along the river's banks.
Over the years, elk and deer populations have increased throughout the region, resulting in much higher numbers than previously existed. Among the effects? A cascade of negative impacts on local flora and fauna.
You see, browsing by elk and deer prevents alders and aspen from growing, and that leads to decreased shade by the river. This causes river water to warm, creating inhospitable conditions for salmon and other fish (last summer’s flows reached a sweltering 83 degrees).
To construct cool refuges, Conservancy staff and volunteers — with the help of contractors and heavy equipment — dug pools in the river, providing an escape from the warmer, shallower portions of the channel.
But healthy rivers and the fish that live there need more than cool water lined with seedlings to thrive. Taller trees equal better shade, which means improved habitat.
Alders and aspen need to grow high enough that elk and deer can’t reach tender leaves and stems. To that end, fences were wrapped around saplings, and black plastic tarps were placed on the ground to prevent competition from other sprouts.
After a morning spent walking the preserve and discussing strategies to restore it, a picnic lunch back at the homestead hit the spot. Basking in sunshine and stunning scenery, a pair of western bluebirds posed for us on a fence, and Lewis’s woodpeckers landed on a dead tree nearby. A yellow warbler sang down by the river, and tree and violet-green swallows wheeled overhead.
The setting could not have been better and, thanks to the impressive restoration work we’d seen, we were full of hope for the future of this incredible river, its surroundings and all of the wildlife it supports.
The Nature Conservancy’s actions at Dunstan — and with neighbors along the river, including the Warm Springs Tribe and U.S. Forest Service — have already improved conditions for salmon and steelhead. With time and additional projects, the future of wild fish here should only get brighter (with the necessary shade, of course).
December 29, 2010
David Harrison, a radiologist living in Salem, serves on The Nature Conservancy's Oregon Board of Trustees.