Thursday, September 1, 2011

Field Going to Oaks

Not all of my management units are large. This place is no more than a clearing among the trees. Many years ago, I removed some cedars in an attempt to let in sunlight, so I could evaluate the possibility of this growing into a quality prairie opening. Before my intervention, it was well on its way to becoming a cedar thicket. Cedar thickets provide a lot of interesting life forms, but Blue Jay Barrens has no shortage of cedar thickets and I was hoping for something a little bit more uncommon.

Several years of ample sunlight resulted in a profusion of deciduous tree seedlings, with a high number of oak species. Oak are declining in many areas and I began to contemplate managing this site toward becoming a stand of mixed oak. I’ve now decided that managing for oaks may be the best choice.

Despite many years of sunlight, very few prairie species have developed. Those that did were species that were already abundant in large open fields. Quality oak trees seem a much better alternative than a small, isolated prairie of low species diversity.

Oaks that were freed from crowding by my earlier cedar clearing efforts have now gained some considerable height. Now that I’m managing for oak, I’m well pleased with the progress these trees have made.

One hundred feet away is the seed source for all of these small oaks. A cluster of about 30 large oaks dominate the crown of a low hill. Soil conditions in the clearing are identical to those enjoyed by the mature oaks, so their seedlings should prosper.

The total area of cedar thicket surrounding the clearing is about one-half acre. Several small oak saplings are trying to maintain themselves in shade beneath the cedar tops. Gradual removal of the cedars should allow the oaks to gain strength and begin to increase in size.

These cedars have suffered greatly from heavy ice and snow loads. If left in place they would eventually fall. There’s never been any doubt that the cedars would be cleared. The question has been how I would try to direct the plant growth that would result from the cedar’s absence.

Other cedars have lost their tops. Large broken tree tops are quite heavy. I’ve seen them fall from the tree like giant spears and stab their jagged ends into the ground. It’s quite shocking to find what looks like a twenty foot tall dead tree where nothing was growing the day before. I use a rope and pulley arrangement to bring down the tree top before I fell the tree. I would hate to be the recipient of one of those falling spears.

So, this opening is now destined to become an oak woods. Management won’t be much different than that required for a prairie. I’ll cut cedars and remove other woody growth. The main difference will be that I’ll leave the oaks and do what I can to insure their survival. It’ll be another 15 or 20 years before the trees become so thick that sun loving plants begin to dwindle. If a rare prairie species shows itself in that time, I’ll just have to change my management goals and start removing the oaks. It’s good to have a definite goal in mind, so I can be more confident in my management decisions for the site.

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