By PAUL HETZLER

What do you call a dairy farmer who spends decades improving the genetics of a herd, then abruptly sells all the best animals to start a new herd from scraggly, unproven stock? Crazy, perhaps, or foolish at the very least (or maybe someone with gambling debts). Under normal circumstances, no livestock farmer culls their best animals to start over with random ones.

Yet it’s common for woodlot owners to sell all the large, well-formed trees during a timber sale and leave nothing but small and defective trees to regenerate the next forest. OK, so my metaphor isn’t perfect—nobody shows up with a tank of liquid nitrogen to help with your tree breeding program—but it’s a reasonable comparison in a lot of ways.

Genetic variation in trees works just like it does in other organisms. If you take a thousand seedlings, some are going to have a slight genetic advantage. Maybe they are more efficient at photosynthesis, or they’re less apt to develop weak (narrow) branch attachments that are prone to breakage. When an unusually straight, fast-growing tree rises head and shoulders above its peers, it’s generally more than mere chance—that tree probably has something the others don’t, and that’s the one you want seeding the next forest.

The multigenerational process of choosing superior genetics in trees is called silviculture. Ideally a forester marks defective trees to cull for firewood, and marks some of the mature trees for harvest. She or he intentionally leaves some of the very best trees for seed.

This kind of timber production is sustainable in both an economic and ecological sense. Not only does the overall gene pool improve, but periodic select harvesting creates openings in the forest canopy, increasing habitat diversity as it releases understory trees.

Many forest owners have heard of silviculture but continue to practice what some foresters call “silver-culture,” maximizing short-term gain at the expense of long-term forest health. The prevailing opinion seems to be that doing the right thing for the environment will hurt you financially. Although that may be true in some instances, it is definitely not the case in forestry.

SUNY College of Environmental Science and Forestry Professor Dr. Ralph Nyland stresses that forestry is a very long-term endeavor. He believes we have to start thinking much farther into the future. Dr. Nyland illustrates why good forestry make the most cents—and dollars—in the following example:

Assume you and your neighbor have identical 100-acre woodlots with salable timber (everything 16” in diameter and larger) worth $20,000. Your neighbor goes for a diameter-limit cut and gets that entire amount. But you mark a select cut, harvesting $10,000 worth of timber and leaving trees of equivalent value standing. It sounds like your neighbor made out better, right?

The next time you can harvest is fifteen years later. By that time, your timber is worth $34,000. You harvest half, leaving $17,000 worth standing. Your neighbor doesn’t have enough salable timber for a harvest yet.

Thirty years after the first cut, your neighbor again has salable timber valued at $20,000. Their total income plus residual value after 30 years is $40,000. Your timber, though, is now worth $77,000, which means that your total income plus residual value after 30 years is $104,000. Now we have two winners, both you and your woodlot.

OK, what do you call a poultry farmer who kills the goose that lays one golden egg each day just to get his hands on two or three gilded ova all at once? Well, for starters you’d call them fictional, but also dumb as a rock. Don’t manage your woodlot like that.

Good forestry will give you a healthy woodlot and a healthy bank account. “Silver-culture” will give you bad metaphors, less money and fewer good trees.

Paul Hetzler is a forester and horticulture and natural resources educator with Cornell Cooperative Extension of St. Lawrence County.