Forests in a Changing Environment

May 23, 2011

Forests in a Changing Environment

Gerald Barnes, MA (Cottage Grove, OR), President of TIE, Inc, and forest geneticist. "Climate change and forest changes."

Jerry Barnes is President of Tree Improvement Enterprises of Cottage Grove, Oregon, and a frequent Sharon Kleyne Hour guest.

Barnes explained that to quickly return a forest to productivity following a timber harvest, you need to replant. If you use seedlings bred (but not genetically modified) to grow fast and straight and resist draught, you can reduce the interval to the next harvest and the trees will be far more valuable. If you also thin the forest at intervals, wood growth will be concentrated into fewer, larger trees.

Tree seedlings should be returned to the site from which the seed was taken. This is a function of latitude-longitude, elevation and aspect (the direction the slope faces). For commercial reforestation purposes, major forest production areas are divided into "seed zones."

Interestingly, you can grow US trees in New Zealand, using the same seed zones. New Zealand is located the same distance south of the equator as Oregon is north of the equator and the climate is similar. In the Southern Hemisphere, north slopes are sunny and south slopes are shady. In the Northern Hemisphere, the opposite is true.

Regarding the changing global environment, forests are certainly part of the environment and health forests are important to everyone. Drastically altering the forestation pattern over a large area (or a small area), can have far reaching effects.

In our changing environment, while there may be a warming trend, there are also greater extremes and many severely cold episodes. Cycles of warming and cooling, both short and long, are natural and constant in Earth's history.

Chlorophyll is the green in plants that release pure oxygen into the air. It is the atmosphere's only source of pure oxygen and it sustains nearly all life on Earth. Oxygen production and weather moderation (not timber) are the major roles of forests. With greater population, more oxygen is required, which will not be replaced by ground cover such as grass or shrubs. The world's human population is growing by a million people a week.

Forests are like crops but bigger and slower growing. Expanding the world's forest base will expand the world's free oxygen. We also need more urban green. Trees have a huge influence on the hydrological cycle.