Old-growth forests


Importance of old-growth forests

"The provision for true old growth should be regarded as an essential activity of forestry, just as the provision for wood, wildlife, recreation, and water."
Minnesota Society of American Foresters, Old-growth Task Force (May 1992)

Old-growth forests are a unique, nearly vanished piece of Minnesota's history and ecology. They are the remnants of the plant life that once covered 51% of the state's forested regions, and their harvest delivered immense wealth to individuals and the government, speeding the development of the state's early economy.

Today, ecologically significant old-growth forests are protected from harvest and represent new valves in modern forest management. Old-growth forests can be compared to similar but harvested forests, and conclusions can be reached about the effect of harvest on soils, plant and animal life, the rate of tree growth, and many other parts of a forest's ecology. This kind of research can help improve forest management approaches aimed at supplying wood reliably to the economy while guaranteeing a healthy ecosystem for future harvest and enjoyment.

Old-growth white pine and red pine forest near Grand Rapids, Minnesota, <em>circa</em> 1900.
Old-growth white pine and red pine forest near Grand Rapids, Minnesota, circa 1900.

Old-growth trees harvested and ready for market, circa 1900.
Old-growth trees harvested and ready for market, circa 1900.

Modern white pine harvesting.
Modern white pine harvesting.

A second value of old-growth forests to modern forest management is to recreate in scattered locations the conditions found in Minnesota's forests of the 1850's, before large-scale commercial logging began. Old-growth forests provide unique habitat, sheltering species which do better in old forests than young, and serving as genetic reservoirs--just some of the benefits researchers have discovered.

Unique habitat

Species benefits

 

Genetic reservoirs

Supercanopy red pine towers over its neighbors.
Supercanopy red pine towers over its neighbors. (photo by Jon Rosales)

We are just beginning to understand the full implications of preserving genetic diversity. But what is understood points toward the importance of genetic diversity for forest health, forest research, and forest restoration and conservation.