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Midwest woodlands have expanded and retreated throughout time. Cooler, wetter decades have reduced the impact of fire and encouraged forest expansion while warmer and drier periods have done the opposite. In more recent times, buckthorn (Rhamnus cathartica) arrived in the area, became highly invasive, and is dramatically impacting forest composition. In the big picture, there are few things that stay the same.
Site before buckthorn removal
Cutting the buckthorn
Treating cut stumps with herbicide
Site after buckthorn removal
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One of the essential services offered at PRI is woodland management. Typically that begins with buckthorn removal and goes on to include native tree and shrub thinning or planting, ground layer species enhancement, and fire management.
The project featured here is a perfect example of this kind of work. At the time of settlement (1860s) this woods was actually a savanna. Subsequent grazing probably maintained its open character for the next 80 to 100 years but also significantly changed the ground layer composition. Once the cattle were removed, the savanna quickly became woods by filling in with all kinds of weedy but native trees and shrubs. Then came buckthorn, which aggressively began to establish a dense population throughout the understory, essentially excluding the true native species from regenerating.
Our objectives at this site were threefold. First, clear out and kill the buckthorn. This was a matter of cutting, piling, burning and stump treating—just plain hard work, really. Some removal and cleanup of weedy native species was also done at this time. The next phase was to re-establish the ground layer vegetation. Greenhouse produced plugs were added along with whatever woodland seed could be found. The third step was to simply develop a good, long-term management strategy that would focus on the end objective of either woods or savanna. In either case, some controlled burning will be part of the plan.
The photos illustrate the short-term results. Continued buckthorn control will be necessary and fire management will be used every 4-5 years, probably in the fall, to maintain and improve this unique woodland plant community.
For more information on woodlands, visit the woodland page in our resource library.
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