Working paper 19: Understory seeding in southwestern forests following wildfire and ecological restoration treatments

Shrubs, grasses, sedges, and forbs form the understory of ponderosa pine and pinyon-juniper ecosystems. They cover the natural openings in these two ecosystems - openings that were much more extensive historically than they are today. While restoration treatments in these ecosystems typically focus on trees, it is also important to restore the natural diversity and productivity of the understory plant community because a healthy understory provides wildlife habitat and fuel for low-intensity fires that maintain forest structure. Restoring a healthy understory may require little or a great deal of effort, depending upon the site conditions and site history.Many sites still support some native understory species, either living or in the seedbank, in which case thinning of overstory trees and conducting some prescribed fires is often enough to promote the growth of a healthy understory. In situations where the treated area is adjacent to a weed-free area with a highly diverse understory, it may be possible to simply let nature reseed the treated site. Still other sites lack native understory species and their seeds, in which case it may be necessary to reintroduce those species as either seeds or seedlings. In this working paper, we cover this last situation - one where active seeding is needed.