Forests make up a significant part of our biosphere, (the part of the earth and atmosphere that supports life). Forests also affect the earth’s climate. Forestry practices can influence the affect that forests have on global climates.
Global Carbon Cycle Carbon, the most common element, occurs naturally in the atmosphere as carbon dioxide. Plants, and in particular, forests, use photosynthesis to convert carbon dioxide to plant biomass. Through decomposition and respiration, carbon regularly cycles through the lithosphere (earth's crust), hydrosphere (surface water) and atmosphere.
As forests grow they use carbon dioxide from the atmosphere to create vegetation. As a result of their respiration, plants release oxygen for animals and humans to use. When trees die naturally or are harvested through forestry, their ability to convert carbon dioxide to carbon is destroyed, and that carbon dioxide remains in the atmosphere, where it contributes to a build up of "Greenhouse Gases" (mainly carbon, water and nitrogen).
The much talked about "Greenhouse Effect" is thought to be causing the earth’s climate to change. The two main contributors to the Greenhouse Effect are the burning of fossil fuels, (oil, natural gas, coal and wood) and deforestation. When fossil fuels are burned they release stored carbon into the atmosphere, and with increasing rates of deforestation, fewer trees are available to remove the carbon dioxide from the atmosphere. In recent history, the burning of fossil fuels and deforestation are occurring at such rates that the increased carbon in the atmosphere is contributing to changing global temperatures and climate.
Forestry Forests act as a carbon bank by storing carbon in vegetation, detritus (decaying organic material) and soil. A carbon sink is a forest in which carbon stocks are increasing. A forest is considered a carbon source when its carbon stocks are decreasing.
Sound forest management practices can remove carbon from the atmosphere by protecting existing forests that are carbon sinks, reducing soil disturbances and increasing forest growth rates. Forestry practices such as silviculture and the management of natural occurrences such as insects, diseases and fire, can also increase or diminish the effects of climate change by influencing the rate of carbon uptake and storage.
When trees are harvested or die due to insect infestations, fire or disease, carbon is released into the atmosphere. Harvesting trees requires using machinery that burns fossil fuels and release more carbon into the atmosphere. The planting and regeneration of forests, creates a sink for carbon through photosynthesis and the storage of carbon in trees in roots, branches and trunks.