Spring 1996
MANAGING MIXED FORESTS --- PROFITABLY
North Central Forest Experiment Station - March 1996
How can you manage forests to make money and have healthy mixes of trees? That's an important question for a lot of hardwood forest owners in the Midwest. Most landowners want to know the best ways to manage their forestland. Since everyone has a different idea of what "best" means, the methods that work for one don't always work well for another. Landowners want to make money (at least every now and then), but they also value the rich diversity in hardwood forests.
NC's Forest Economics unit in East Lansing studies problems just like this. They look for practical and profitable ways to increase forest productivity. They compare the costs and benefits of managing the region's public and private forests to meet landowners' goals. They estimate the economic potential of the region's forests to produce timber and other forest benefits. And they develop information and tools to help forest owners compare their options and maximize value. Their goal, simply put, is to find and evaluate the most productive and profitable ways to manage forests.
But back to the question of how landowners can manage their forests to get good payoffs and maintain the tree mixtures they value. Research economists Mike Vasievich and Jeff Niese teamed up with Terry Strong, research forester at the Rhinelander lab, to study the question. The three looked at the tradeoffs between profits and some measures of biodiversity like tree species richness.
They found some answers on NC's Argonne Experimental Forest in northern Wisconsin. Forty years ago, researchers there set up studies to compare harvesting methods. The experiments were rich with biological data, but no one had ever looked at how profitable the treatments were or how species diversity changed. Like Wall Street analysts, the scientists set about figuring growth, comparing costs, projecting prices, and calculating return on investment. They were searching for evidence that some methods of harvesting might be both more profitable and produce better mixtures.
Here's what they found:
Clearcutting, an appealing approach for some landowners interested in a quick payoff, produced one of the highest levels of tree species richness, but had the worst long-term economic performance. Shelterwood cutting (another even-age management silvicultural practice) also produced excellent species richness but was much more profitable than clearcutting.
Timber stands that were not cut at all became dominated by sugar maple and had the lowest tree species richness.
The partial cutting strategies (various levels of individual tree selection harvests and diameter limit cutting) produced a range of results, but the medium selection harvest was the clear winner. Cutting back to 75 square feet per acre produced high species richness and the highest profits over the four decades.
These results can be applied to the 10 million acres of northern hardwood forests in the Lake States. This research is only one example of how our social scientists find answers to people's questions about important economic and biological tradeoffs in forests. Small private landowners and large public forest managers can use their research to manage in a cost-effective and profitable way and achieve other goals together on the same landscape.