ENTERPRISE, Ore. — Putting up a small ponderosa pine timber sale didn’t pan out for managers of Eastern Oregon’s Zumwalt Prairie Preserve, so they hired sawyers to fall the trees strategically for the benefit of wildlife.
Tucked into the north-facing slope of one of the Zumwalt Prairie’s sleeping volcanoes known as The Buttes are a handful of acres of ponderosa pine, a forest inhabited by cougars, deer, elk, small mammals and birds of all sorts.
Ponderosa is a fire-tolerant species and in the absence of regular intervals of wildfire, stands grow too dense for ample sunlight to reach fruiting shrubs like Hawthorn, chokeberry, snowberry and gooseberry, which serve as food and cover for the savannah sparrow, grasshopper sparrow and other grassland ground-nesting birds.
Zumwalt Prairie Preserve manager Jeff Fields said the initial focus was opening up the stand, first with prescribed fire in 2014. However, not enough of the trees were killed, so to thin the forest even further he said he talked to a couple of loggers about buying the trees he wanted removed. The price of pine wasn’t profitable, so they turned him down.
“Access isn’t easy — it didn’t pencil out,” Fields said.
Still faced with an overstocked stand, one of the contractors with whom he consulted suggested dropping the trees and leaving them on the forest floor in such a way that the brushy branches would protect the fruiting shrubs from being eaten by the prairie’s herds of elk.
Eric Sinclair, a logger and urban arborist, said he suggested a method he had seen used in a city setting. A tree is felled at the sawyer’s chest height, eliminating the crushing blow of the lower trunk onto a flower bed or sidewalk.
“We nicknamed it the Daisy Patch, because you can fall a tree without damaging the surrounding landscape,” Sinclair said.
When executed perfectly, the butt of the tree and its stump are still connected, looking like the notch in furniture joined with mortise and tenon.
Sinclair said he and fellow logger Pat Doherty watched You Tube videos of the technique before applying it to the tiny ponderosa forest.
According to Doherty, the videos also showed the mortise and tenon cut used in a Midwest forest where sawyers were attempting to protect aspen stands.
“We came up with the idea of trying to corral off certain parts of the forest with trees that needed to come out anyway,” Doherty said.
The mortise and tenon cut worked best, Doherty said, when falling a tree on level ground or slightly uphill. If a tree had big, strong, heavy limbs on the falling side, its butt would catapult out of the notch.
Another challenge, especially for these experienced sawyers, was the technique isn’t good for directional falling.
Doherty said, “You can’t really a steer tree with it — and if the limbs brushed the canopy it would grab the tree, twist it and pop it off the stump. It’s a moody cut — when it goes just right it goes really well. Watching a 90-foot tree drop in place is really cool to watch.”
Sinclair agreed that the mortise and tenon cut was a good skill to have in the tool box.
“It was good overall — a little more tedious and time-consuming, though the end result was really neat,” Sinclair said. “The butt of the tree should stay up off the ground for a long time, protecting the shrubs.”
Opening the pine forest to more light and protecting fruiting shrubs was part of a larger body of conservation work on the prairie paid for, in part, by Oregon Watershed Enhancement Board. The Nature Conservancy and Clint Krebs, a Zumwalt Prairie cattle and sheep rancher, also contributed money and labor for the grant’s other objectives — spring developments, watering troughs, solar pumps and hardware as well as electric fencing to protect the springs.
The state funding required before and after activity monitoring.
“Whatever we do, whether it’s water development, weed management or prescribed fire in the grasslands, it is all to improve habitat quality for native bird species,” Fields said.