What's happening at the Clear Lake Nature Preserve?
July 26, 2017
The Clear Lake Nature Preserve including Brennan Woods is open! The preserve was closed to the public a few months in the spring of 2017 during a selective tree harvest. Even though the preserve is open, the land looks quite different after the tree harvest and after the prescribed fire we completed earlier in the year on the preserve. More recently, some residents and visitors are noticing the brown field on the west side of the preserve.
Not surprisingly, some are asking, why all this activity?
We're glad you are interested! Here are the reasons and the vision. Converting the 46-acre, Clear Lake Nature Preserve & Brennan Woods to its former open oak woodland continuum (meaning the preserve includes an oak savannah ecosystem that gradually becomes an open oak woodland ecosystem) requires all these steps--a selective harvest, a prescribed fire, and vegetation management.
Under the direction of a forestry consultant, over the last several months, large equipment has removed carefully selected trees. A variety of sizes, including large mature trees, and various species, including cottonwood, a variety of oaks, hickory, maple, black cherry, bigtooth aspen and others, were removed to open up the canopy and convert the forest back to an open oak woodland. Around 200 trees were removed with over half being cottonwood trees. While they are native to our area, they are not desirable in the oak woodland ecosystem. Timber harvesting is used as a management tool to change the light levels in the forest, to stimulate regeneration, and to change the very structure of the forest. It can be controversial, it can be hard to understand, and it can be ugly!
When timber is harvested, the process looks and is somewhat chaotic. Bits of the tree, like the tops, remain, temporary access trails are installed, erosion occurs, and occasionally residual trees are damaged or taken out in the process. Now that the harvest is completed, the tops and remaining debris will deteriorate and add important nutrients back into the soil and in the meantime serve as habitat for wildlife. The temporary trails will revegetate and the overall erosion was minimal. The timing of the harvest was intentionally done in late spring, early summer to allow time for vegetation to reestablish helping to minimize the potential for erosion.
Removing these carefully selected trees will help us reach our restoration goal of opening up the canopy to allow more light to reach the forest floor. Before the harvest, the canopy was so thick that oak saplings, for example, could hardly receive enough sunlight to grow for natural oak tree regeneration. The prescribed fire earlier in the year helped to remove a thick leaf litter layer, creating more ideal growing conditions for native understory plants, including baby oak trees!
Next steps? Vegetation management will continue over the next few years. Activities will include herbiciding, seeding, cutting and pulling, mowing, and prescribed fire. The large patch of brown field on the west side of the preserve was sprayed, by a licensed professional, with herbicide. Native seed will be dispersed, replacing the non-native vegetation currently there. Over time, this portion of the preserve will be restored to a native oak savanna.
What's the longterm vision? In addition to the restoration activities, our summer intern, Jonathan Moss, with the guidance of our Lands Committee and input from the community, is designing a hiking trail through the preserve. We are determining the location of a small parking area, the location of the trailhead and how many trailheads we should offer, signage locations and wording, and other aspects of the trail installation. Our goal in creating the trail is to help protect important features of the preserve while encouraging exploration and enjoyment of this beautiful property.