A recently published study from research on the Malheur National Forest is powerful evidence that the ongoing effort to restore ailing public forests in Northeastern Oregon through selective logging is working.

Also known as “thinning,” this tactic has been one of the main tools for forest managers since logging that included, or even concentrated on, older, larger trees was largely curtailed in the early 1990s.

That transition to today’s emphasis on thinning overcrowded forests was spurred by multiple issues, including legal challenges by groups that want to preserve remaining old-growth forests, federal Endangered Species Act listings, and the dwindling acreage of old-growth forests.

Over the past few decades, the U.S. Forest Service, which manages most of the public forests in this corner of Oregon, has focused on removing trees from forests which, based on historical records, had more trees growing than in the past.

In some places, thickets of fir trees, which have taken advantage of the mostly successful firefighting strategies over the past century or so, have encroached in areas once dominated by ponderosa pines.

Elsewhere, the composition of the forest remains primarily ponderosa, but an excessive number of trees competing for a finite supply of water and soil nutrients has stunted the trees’ growth and made them more susceptible to insects, disease and, as our increasingly smoky summer skies show, wildfire.

The basic idea with thinning is to reduce the tree density, removing mainly the smaller trees and, in the case of stands where firs have encroached, giving priority to cutting that species. The goal is to help the remaining trees, particularly ponderosa pines and, in places, tamaracks and Douglas-firs, grow faster. Those species, and in particular ponderosas and tamaracks, are naturally more resistant to insects, disease and fire.

A research team led by James Johnston of the Oregon State University College of Forestry has been studying the effects of thinning, in 2014 and 2015, on a 7,200-acre section of the Malheur National Forest. This is a ponderosa pine forest.

The researchers, from OSU and the Forest Service, found plentiful evidence that the thinning benefited not only those trees, but the wider forest ecosystem.

Trees grew faster after thinning, according to the study. They also produced larger amounts of carbohydrates, which Johnston said suggests the trees will be more resilient against insects and other threats.

The researchers also documented more diversity in grasses, forbs and shrubs on the forest floor.

Johnston’s study is the latest evidence that the thinning projects going on across the region — including the long-term East Face project along the Elkhorn Mountains from the Anthony Lakes Highway north to near La Grande — are beneficial.

Those projects are expensive, though, in part because the trees cut are mainly small ones that have little or no commercial value.

Congress should strive to boost budgets for forest restoration, which is needed on hundreds of thousands of acres across the region.