growth creates land needs from smallholders in developing and least developed countries. Slash-and-burn entails the removal of all stems in a particular area. This can be a form of deforestation, when the land is converted to other uses. However, some indigenous forest peoples, for example the 19th century Forest Finns rotate over the land and it does return to forest and this would be sustainable. Slash and burn techniques are typically used by civilians in search of land for living and agricultural purposes. The forest is first clear cut, and the remaining material is burned. One of the driving forces behind this process is a result of overpopulation and subsequent sprawl. These methods also occur as a result of commercial farming. The lumber is sold for profit, and the land, cleared of all remaining brush and suitable for agricultural development, is sold to farmers. Clearcutting contrasts with selective cutting, such as high grading, in which only commercially valuable trees are harvested, leaving all others. This practice can reduce the genetic viability of the forest over time, resulting in poorer or less vigorous offspring in the stand. Clearcutting also differs from a coppicing system, by allowing revegetation by seedlings. Additionally, destructive forms of forest management are commonly referred to as 'clearcutting'. Clearcutting regeneration, harvesting or system Clearcutting can be differentiated into Clearcutting - clean felling by complete exploitation and removal of all the trees in one operation ... a harvesting method Clearcutting method - a method for regenerating an even-aged community by removing all the mature trees Clearcutting system - a silvicultural system incorporating the clearcutting method to remove (clear) the mature community over a considerable area at one time Confusion between these different uses of the term is common. Furthermore, as indicated above many variations mean technically correct usage may not be descriptive enough to know what is meant on that particular occasion. A clearcut is distinguished from selective logging where typically only a few trees per hectare are harvested in proportions dictated by management objectives. Clearcut logging is also distinct from wildland fire use, and from forest thinning. In these latter two it is common practice to leave trees that are considered undesirable, such as those that are too diseased, stunted or small to be marketable. Selective logging is usually practiced in areas with access to infrastructure. Effects on the environment Environmental groups criticize clear-cutting as destructive to water,