Vincent Corrao, Northwest Management, Inc.
Managing a forest is pretty simple…You mark the dead and dying trees to cut, thin a few here and there and you have a nicely managed forest!! The trees look healthy, are spaced evenly and to most observers look like they are growing.
Today, silviculture, the art and science of growing trees, is combined with ecosystem management and landscape management, and when we are done with all these ideas, we say, “this is good.” The question becomes, “What is good for tree health, ecosystem stability, and the inhabitants of the forest (humans included)?”
In Europe, especially Germany and Austria where forest management has been practiced for centuries, some questions have come to the surface on tree health, soil productivity and tree growth. Multiple rotations of single species (i.e. planted spruce stands) have depleted or are suspected of depleting nutrients, and have weakened tree health, producing less growth and may not be the best management for the forest ecosystem. Over the years, the rotation of spruce and conifers was preferred over many of the hardwood species. Nutrient recycling, lost from the absence of the hardwood species and the concentration of only a few specific species has changed the productivity of the soil and consequently lessened tree growth.
Managing a forest for a large number of species with varying age classes, heights and diameters provides stability and diversity, which can be very productive for tree growth, wildlife habitat and with proper species selection be more resistant to insect and disease problems.
Managing a forest in this manner requires careful selection of the trees to leave, and protection of the seedling, sapling and pole size trees.
The crowns of the trees left in the forest should be very pointed and conical, extend 30 to 50% or more of the total tree height and should exhibit a nice green color. The regeneration should be thinned so that the healthy vigorous trees can take advantage of the thinning of the larger overstory trees and provide replacement trees as other trees fall out of the stand due to mortality or harvesting activities. This type of management requires that the trees to be left or removed be marked to insure that the management objectives are being met. Each tree species has it’s own ecology of where it like to grow and when considered, the trees will have higher growth rates. Careful selection of an experienced logging contractor with the right size equipment will make all the difference in the quality of the harvest and protection of the regeneration.
The next time you hear someone talk about silvicultural prescription, ecosystem or landscape management, ask them if there are considering the health of the individual tree, spacing of these trees, future productivity and the impact that this management will have on the forest.