By Amy Grotta, OSU Forestry & Natural Resources Extension – Columbia, Washington & Yamhill Counties

A free-to-grow tree coexisting with its early seral neighbors
A free-to-grow tree coexisting with its early seral neighbors

Early seral…it’s one of the biggest buzzwords in Pacific Northwest forestry these days.  But what is it? Put simply, early seral refers to the first stage in forest development following any disturbance, including wind, ice, fire or logging. An early seral, or early successional community is made up of the first colonizers of a forest opening: grasses, other herbaceous plants and broadleaf shrubs.

This biologically rich early seral stage was highlighted as a high priority at last year’s Wildlife in Managed Forests Conference (I did promise I’d eventually get back to writing about that!). It’s also an important component of the “ecological forestry” strategy that is proposed under the Wyden bill for management of federal forest lands.

There are several reasons why these early successional communities are the subject of research and policy discussion. One is their value for wildlife: these hardwood mixtures contain a high variety and abundance of foliage, fruit and pollen used by all manner of insects, birds, and larger animals. In fact, some birds rely almost exclusively on this landscape component.

Time series of early succession in the Mt. St. Helens blast zone. Credit: USDA Forest Service, Mt. St. Helens National Volcanic Monument
Time series of early succession in the Mt. St. Helens blast zone. Credit: USDA Forest Service, Mt. St. Helens National Volcanic Monument

Secondly, there’s not as much of it as there used to be. “Wait a minute”, you say, “what about clearcuts? Shouldn’t there be more early successional sites on the landscape?” The thing is, most landowners want to get trees growing again as quickly as possible; and our Forest Practice rules require it. Shrubs and grasses are seen as getting in the way of this objective, for good reason. So, in effect, the early seral stage on most private lands begins to disappear as soon as the trees are Free to Grow; by law, in six years. On the other hand, early seral communities can last decades when they evolve naturally after a big disturbance, without any trees being planted. In fact, much of the thinking behind early seral characteristics comes from research done at Mt. St. Helens, where these communities persist 30 years after the blast. In fact, as I heard one scientist put it, when it comes to early seral communities, “regeneration failure is success!”

Obviously, on private lands, regeneration failure is not what we are after! So, there’s quite a bit of research going on at OSU and within private industry about how to balance the competing objectives of growing new trees quickly while maintaining the structural characteristics of an early seral community.

Meanwhile, as a small woodland owner, you may find that your land management goals allow some room for these early seral habitats. So while we pay attention to what the science tells us, there are also examples and lessons to be learned from other woodland owners who have successfully (or unsuccessfully) tried to encourage early seral communities in their regeneration areas. This summer our Master Woodland Manager class visited a clearcut where, thanks to some careful management, the trees are free-to-grow and deciduous plants are thriving. (See photo at top of post.) Herbicides were used to control bigleaf maple clumps and to free up growing space around the trees, but shrubs such as elderberry and hazel were left to grow in spaces between the trees.

Are you a bird enthusiast? Then you might take a page from the Hayes family, who has been monitoring birds in different types of forests on their land, from mature, closed-canopy timber to “variable retention” areas where forest openings (i.e. early seral communities) were created through a partial harvest. Watch a video to see what they’ve found. Read a recent case study to learn more about the variable retention harvest featured in the video.

“Early seral” may not yet be the topic of your next dinner party. But in the conversation of forestry, it appears that this is one that’s here to stay for a while.

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One thought on “Chasing early seral

  1. Seems particularly adaptable to small woodlands where the owner’s goals may be broader or management can be readily adjusted to include wildlife habitat. Couple of thoughts:

    • Many early seral deciduous brush species are also tolerant of shade of the sort retained with timely thinning. Those tolerating partial shade include red osier dogwood, Douglas hawthorne, black twinberry, chokecherry, most of our currants, roses and blackberry kin, many of our willows, and blue elderberry. Those tolerating ¬full shade include hazelnut, oceanspray, vine maple, serviceberry, cascara, crabapple, indian plum, ninebark, red elderberry, snowberry and red huckleberry. It is possible to maintain shelter, browse, fruit, nut and seed sources within a managed largely coniferous timber stand.

    • Where bigleaf maple sprouts (of whatever age…) are an issue, sites may be regenerated with shade-tolerant conifers (cedar, spruce, hemlock, grand-fir) within the FPA rules (discuss specifics with your Stewardship Forester). The FPA rules also allow, with planning, considerable flexibility for maintaining functional meadow and transitional habitats. For federal income tax purposes, there are good biological reasons for diversity within a timber stand. And, increase in the value of the land (which may be a benefit of attention to wildlife habitat) can be considered as well as increase in timber value. (See p. 26, Ag Handbook 731; While the regulatory system limits managing for habitat, the constraints can be worked with.

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