If all you have is a hammer…
January 24th, 2008 fmorgan…everything looks like a nail. This is a phrase I think about a lot because it says that if our tool collection is small, we often “fix” things in a manner that doesn’t make sense.
After all these years, I am now seeing how often forestry practices are, quite frankly, very primative. It is almost as though forestry engineers are being brought kicking and screaming into the idea of maintaining existing ecosystems instead of just having a job identifying trees and marking them for harvest.
As an example, CATIE has been researching for 10 years here in Costa Rica how to grow mahogany without attracting a certain moth that lays its eggs in the tips of the young trees so that when they hatch, the larvae bore into the tip. CATIE now has results that look good, and we are using the methods they have researched. Since the damage to the tree occurs on the tip and only occurs twice a year, it works fine to prune after the damage. Also, planting inside brush helps a lot too, since the moth overflies the trees. After the mahogany tree is 6 meters tall, there is no more problem.
Various trials were done, but I was truly surprised that they didn’t try two that seem to be pretty safe bets. One would be to use a dormant spray to smother the eggs when first laid. You can predict almost to the week when the moths will lay their eggs, so a dormant spray could be very effective. Dormant spray is used in the North a lot for fruit trees. The other idea is to use bat houses to concentrate predators in the area. The photo below shows the type of bat houses we’re making. They will be mounted on rough posts that go all the way inside that the bats can climb up on.
I don’t know yet if these two approaches will work, but I really shouldn’t have been surprised that they weren’t tried. Forestry often resembles a horse with blinders, in that there is very little interaction with other fields, like growing fruit trees and organic farming. I do believe this is because forestry, up until recently, has been focused almost entirely on harvesting and managing existing forests, not in rebuilding forests.
It is so interesting to me that there are so many possibilities for learning inside our plantations and forest. A common question I get is how long do I think I will be interested in planting trees. The answer is probably forever, since there is so much to learn and so much to discover. You would think growing trees would be simple and in some ways it is, but there is so much room for improvement!