Forest Ecosystems

Written by Peter Kolb, University of Montana

A photo a forest landscape in the United States. Photo courtesy of Peter Kolb, University of Montana

Forest ecosystems are the combination of species, geology, topography, and climate tied together by physical and biotic processes specific to any one site, and most importantly occupied by trees as the dominant vegetation. A forest ecosystem may be as small as a tree branch microsite where mosses, insects, and microscopic organisms interact or as large as the boreal forest that encircles the Earth at northern latitudes. The larger it is, the more complex the potential interactions. Considering that a thimble of forest topsoil may contain more than 20,000 individual organisms, completely understanding how each species in a forest influences and interacts with others is a daunting if not impossible task. On the other hand, much is known about larger organisms such as trees and how they function, interact with, and influence their surroundings. Forest management or “forestry” is one of the oldest forms of agricultural practice, stemming from the need of human occupants to capture and cultivate tree species to supply their basic needs such as food, shelter, clothing, and heat.

The study of these systems can be broken down into specific topics such as forest soils, dendrology, regeneration, hydrology, ecology, physiology, genetics, entomology, pathology, microbiology, biochemistry, horticulture, harvesting, wildlife, measuring, engineering, wood products, etc., and within each of these disciplines are further refined research specialties. The amount of information available is incredible, and it would take more than several lifetimes to study them all, yet the quantity of knowledge we are gaining from current research adds significantly to that knowledge every year. Forests can be managed successfully to be sustainable and meet specific objectives. Forests can also be left alone to let natural processes determine the future. Trees have been

Diagram of various components that comprise forest ecosystems in the United States. Illustration courtesy of Peter Kolb, University of Montana.

around for millions of years and are thus highly diverse and adaptable. At the same time, a tree species on a particular site can be very dependent on a certain level of climatic stability because they lack the ability to uproot and move to where conditions are better. Climate change, as a phenomenon either influenced by nature or humans, has the potential to change forests and their inhabitants dramatically and thereby directly impact the humans that depend on these ecosystems for clean air, water, wood, psychological well-being, recreation, and multiple other resources. Humans have the potential of either positively or negatively influencing the future of global forest ecosystems.

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