One of the most important responsibilities of the USDA Forest Service is to restore forests following disturbances such as wildfire, harvest, and invasions by insects, diseases, and other stressors. Establishing plants in disturbed areas helps prevent soil erosion, create wildlife and pollinator habitat, protect watersheds, and develop forests for recreation, timber, and other uses.
The Forest Service National Center for Reforestation, Nurseries, and Genetic Resources (RNGR) program provides technical support and expertise to help with every step in the reforestation chain. Nationwide, there are approximately 1,500 forest and conservation nurseries producing over one billion seedlings annually to be outplanted on federal, state, tribal, private, and industrial lands. Six Forest Service nurseries grow about 25 million seedlings annually for the agency’s 155 national forests and 20 grasslands.
Seedlings of the correct species, genetics, and size are grown in nurseries to match the location and environment of their designated restoration site. Nursery staff package the seedlings and place them in cooler or freezer storage until conditions at their designated restoration sites are favorable for outplanting. Ideal conditions and planting dates vary depending on location and are important for ensuring seedlings have the greatest possibility for establishment, survival, and growth. For example, a coastal site has relatively mild temperatures and high soil moisture, so planting can occur as early as January. A high-elevation mountain site, however, may have a lot of snow, below-freezing temperatures, and frozen soil, so planting cannot occur until late spring. In the arid Southwest, planting occurs during the summer monsoon season when soil moisture is highest.
Prior to planting, foresters prepare the site by clearing debris and competing vegetation. During planting, seedlings must be handled very carefully and protected from temperature extremes, drying out, and physical damage. Planters select a suitable planting spot, dig the hole to the proper depth, gently place the seedling in the hole, and then tamp the soil around the seedling’s roots. Some sites require extra measures to give seedlings the best chance for survival, such as dipping seedling roots in water right before planting, installing mesh tubing to protect from deer or elk browsing, or fertilizing to improve soil conditions. Foresters monitor restoration sites for a few years to check whether seedling survival meets targets. If survival is too low, then the site will be scheduled for replanting.
Along with seed collection (see Seeds – The Heart and Start of a Forest) and seedling production (see Nurseries – Growing Future Forests), outplanting is a critical link in the reforestation chain that contributes to nationwide ecosystem restoration efforts. The Forest Service RNGR program helps ensure this chain remains intact.