It is a cornerstone of Oregon’s forest practices rules. Requiring landowners to promptly replant trees after a timber harvest means future Oregonians will enjoy the same forest resources we do today, including wood products, healthy watersheds, recreational opportunities, and thriving fish and wildlife habitat.
In a typical year, Oregon forest landowners plant about 40 million seedlings every year. And far more trees are planted each year than are harvested.
Oregon tree planting crews enjoy a rare clear, sunny morning in February's coastal mountain range. Despite the cold and taxing terrain, the planting goes on.
Landowners must complete replanting of harvested ground within two years.
Within six years of harvest, the young trees must be “free-to-grow.” That means they are vigorous and tall enough to out-compete grass and brush, and will grow into a new forest.
Trees per acre.
Depending on the site, the rules require that at least 100 to 200 trees per acre survive during reforestation, but landowners typically plant about 400 seedlings per acre.
Differences in eastern Oregon.
The law also requires successful reforestation in eastern Oregon; however, natural seeding reduces much of the need for hand planting.
Nurseries, many of which are in Oregon, produce millions of healthy, high-quality seedlings, grown from seeds harvested from native tree species that match the planting area’s latitude and elevation.
You may have seen the statistic in some of OFRI’s educational media and other places that about three trees are planted for every one harvested in Oregon. The three-to-one ratio we use in our educational media, falls roughly in the middle of the low and high ends of the tree planting to harvesting ratio spectrum in Oregon. It’s important to note that our tree planting to harvesting ratio estimate mostly applies to western Oregon. The reason for that is western Oregon’s Douglas-fir dominant forests are where the most clearcutting followed by mass tree planting takes place.
Planting is commonly done on a 10’ x 10’ spacing, which equals 436 trees per acre (tpa). Some landowners plant a bit tighter and some plant a bit wider, but 436 tpa is a good average to use.
A 50-year-old stand of Douglas-fir trees with no commercial thinning has about 150 tpa at harvest, so 436 divided by 150 equals 2.9, or nearly three trees planted for each one harvested. A stand of 70-year-old trees with no commercial thinning has about 110 tpa at harvest. If you divide 436 by 110 that equals 3.96, or nearly four trees planted for each one harvested.
There are many variables based on landowner goals and site characteristics. Read our blog to get a clearer picture of the ratio between planted trees and harvested trees in Oregon.
Reforestation is an essential part of active forest management. Before harvest, foresters determine the best plan of action to ensure the regrowth of a healthy forest. Sometimes this means immediate replanting, while other times it means leaving trees as seed sources. Where appropriate, seedlings of several different tree species are planted to maintain diversity in a working forest.
Seedlings are planted while they are dormant, to take advantage of cool, wet weather conditions that promote good root development. This means seedlings are typically planted from winter into early spring by crews of reforestation workers who plant each new tree by hand.