Clearcutting, or clearfelling, is a controversial forestry/logging practice in which most or all trees in a harvest area are cut down. Logging companies and forest-worker unions in some countries still support the practice for safety and economical reasons. Detractors see clearcutting as synonymous with deforestation, destroying natural habitats and contributing to global warming.
Many variations of clearcutting exist, the most common professional practices are:
Additionally, destructive forms of forest management are commonly referred to as 'clearcutting'.
Limited clearcutting can be practiced to encourage tree species that require high light intensity. Generally, a harvest area wider than double the height of the adjacent trees will no longer be subject to the moderating influence of the woodland on the microclimate. The width of the harvest area can thus determine which species will come to dominate. Those with high tolerance to extremes in temperature, soil moisture, and resistance to browsing may be established, in particular secondary successional pioneer species.
Clearcutting is sometimes used by foresters as a method of mimicking disturbance and increasing primary successional species like poplar (aspen), willow and black cherry (North America). Clearcutting has also proved to be effective in creating animal habitat and browsing areas, which otherwise would not exist without natural stand replacing disturbances such as wildfires, large scale windthrow, or avalanches.
In temperate and boreal climates, clearcutting can have an effect on the depth of snow, which is usually greater in a clearcut area than in the forest, due to a lack of interception and evapotranspiration. This results in less soil frost, which in combination with higher levels of direct sunlight results in snowmelt occurring earlier in the spring.
Clearcutting can have major negative impacts. These have been cited as: soil erosion, poor quality re-growth, increased risk of pest epidemics, increased wildfires, loss of biodiversity, and loss of economic sustainability and increased environmental instability, loss of carbon contributing to global warming and so on.Unfortunately the response of governments around the world has sometimes been to marginalize community, environmental, social and academic concerns and defer to the logging industry.
Old-growth wood often bears the scars of countless centuries, focusing interest on optimally reproductive mid-growth trees, the forest powerhouses that in most market species are 200 to 500 yearts old. In undisturbed environments, old-growth forest shelters many optimal specimens. A number of attempts have been made to ameliorate the effects of clearcutting: encouraging natural regrowth, careful selective seeding (monocropping) and burn-out. However these attempts have to date been poorly managed and sporadic, and not based on unbiased forestry science. Where resource economies do not include purposeful seeding, the resulting clearcut re-growth is always unhealthy and prone to fire damage.
Clearcut re-seeding (that is improperly planned) has all of the same negative fire and disease effects of natural regrowth clearcuts. Another reseeding disadvantage, that is extensive where managed forestry companies exceed cuts and fill in slope margins with compulsory plantings, is mono-crop disease leading to soil failure. For instance, clearcutting on steep slopes always results high soil erosion rates. Tree species that can handle higher soil acidity (associated with soil erosion) and with roots suitable to retain and partially rebuild soil, such as pine trees in monocrop plantations. Unfortunately, extensive use of pine has wiped out millions of hectares of diseased and burned re-growth forests. The pine beetle larvae lacking the checks found in old growth and are now epidemic in North America. Pine beetles burrow into re-growth pine mono-cropping and kill the trees just when they enter their productive life-cycle point of rapid growth that should last 100 to 200 years. Dead clear-cut trees are accelerants in wildfires that are removing incresing amounts of the commercially useful vegetation in their path each year.
Burnouts are not helpful, though they represent the only known option to immediately protect property in the line of active fire. It was once thought that careful clearcut burnouts set to target just certain very congested patches and only certain undergrowth flammables would limit fire damage in expanding clearcut zones. However, this did not limit wild fire incidence or extent across decades. In fact, it did create a huge cache of wild fire fuel, as forest cleaned by burnout become even more stressed by lack of biodiversity, soil erosion and disease. Burnouts are coupled with wildfire suppression. This has disastrously increased re-growth fire fuel: by putting out wild fires, what burned small four decades ago becomes accelerant for much greater fuel mass during inevitable future fires.
In British Columbia, Canada where forestry is almost exclusively clearcut, both the extent and the frequency of wild fire are increasing as a century of the practice. Leveling 80% of the available forestry resource has resulted in a biomass of flammable, unhealthy, and weedy fire fuel and pest food. In addition, in approximately one tenth of British Columbia forests, where re-seeding has been carried out to ameliorate the effects of unattended re-growth forests, destruction of tree-crop due to forest pests has resulted. Clearcutting has created problems for British Columbia that some feel will persist. It is hoped that restricting human activity into and around clear-cut may lessen current outcomes for human fatality, fire incidence, and tree-crop loss.
There are no plans for regeneration of healthy forest. Forestry companies are turning to harvest natural regrowth every twenty years or so before fire and pests hit, providing a market in small wood objects like chopsticks. No industrial attempt is made to mimic the healthy universal biodiversity of old-growth forest. When replants die out, the land is abandoned. To date, no government or science has costed and effectively assessed the complexity of restablishing biodiversity lost to clear-cut. Human beings simply complain about carnage or coddle concerns for a few isloated species. A few large corporations with a quota pointed at public placation have provided a few tiny plots of model old-growth in tourism venues. Governments claim to be protecting remote wildreness where a constant flow of cut timber is seen towed out to sea in huge carfully constructed ramps of tied logs.
Historically, human habitation has used clear-cut as a method to try and restrain a biosphere that would always recover within a few years and inundate human activity. Modern science and industrial methods have globally decimated the biodiversity that appears to sustain optimal health and survivability for life on earth. The single outlook for clear-cut is environmental devastation. We do not have the physical resource, the cultural controls or the science and technology to repair forests that we have turned into reservoirs of extinction. Any image of scorched earth under mono-crop forest's black poles in British Columbia accurately illustrates just a very small parcel of the future environment for deforested earth's undirected human population. However, this reality seems only to fuel the technocratic economies destroying environment today. Clearcutting is the ultimate deadly global conundrum to which no words can deliver justice. Our future, the coming millenium so clearly invites images of failed human economy and culture in a global desert, treeless and barren.