DeforestationIntroductionDeforestation,clearanceorclearingis the removal of a forest or stand of trees where the land is thereafter converted to a non-forest use.[1]Examples of deforestation include conversion of forestland to farms, ranches, or urban use.The termdeforestationcan be misused when applied to describe a tree harvesting method in which all trees in an area are removed (clear cutting). However intemperate climates, this method is in conformance withsustainable forestrypractices, and correctly described asregeneration harvest.[2][not in citation given]Intemperate mesic climates, natural regeneration of forest stands often will not occur in the absence of disturbance, whether natural or anthropogenic.[3]Furthermore, biodiversity after regeneration harvest often mimics that found after natural disturbance, including biodiversity loss after naturally occurring rainforest destruction.[4][5]Deforestation occurs for many reasons: trees are cut down to be used or sold as fuel (sometimes in the form ofcharcoal) or timber, while cleared land is used aspasturefor livestock, plantations of commodities and settlements. The removal of trees without sufficientreforestationhas resulted in damage tohabitat,biodiversityloss andaridity. It has adverse impacts onbiosequestrationof atmosphericcarbon dioxide. Deforestation has also been used inwarto deprive the enemy of cover for its forces and also vital resources. Modern examples of this were the use ofAgent Orangeby the British military in Malaya during theMalayan Emergencyand the United States military in Vietnam during theVietnam War. As of 2005, net deforestation rates have ceased to increased in countries with a per capitaGDPof at least US$4,600.[6][7]Deforested regions typically incur significant adversesoil erosionand frequently degrade intowasteland.Disregard of ascribed value, lax forest management and deficient environmental laws are some of the factors that allow deforestation to occur on a large scale. In many countries, deforestation, both naturally occurring and human induced, is an ongoing issue. Deforestation causesextinction, changes to climatic conditions,desertification, and displacement of populations as observed by current conditions and in the past through the fossil record.[4]More than half of all plant and land animal species in the world live in tropical forestsCausesAccording to the United Nations Framework Convention on Climate Change (UNFCCC) secretariat, the overwhelming direct cause of deforestation is agriculture.Subsistence farmingis responsible for 48% of deforestation;commercial agricultureis responsible for 32% of deforestation;loggingis responsible for 14% of deforestation and fuel wood removals make up 5% of deforestation.[9]Experts do not agree on whether industrial logging is an important contributor to global deforestation.[10][11]Some argue that poor people are more likely to clear forest because they have no alternatives, others that the poor lack the ability to pay for the materials and labour needed to clear forest.[10]One study found that population increases due to high fertility rates were a primary driver of tropical deforestation in only 8% of cases.[12]Other causes of contemporary deforestation may includecorruptionof government institutions,[13][14]theinequitabledistribution of wealth and power,[15]population growth[16]andoverpopulation,[17][18]andurbanization.[19]Globalizationis often viewed as another root cause of deforestation,[20][21]though there are cases in which the impacts of globalization (new ows of labor, capital, commodities, and ideas) have promoted localized forest recoveryIn 2000 the United NationsFood and Agriculture Organization(FAO) found that "the role of population dynamics in a local setting may vary from decisive to negligible," and that deforestation can result from "a combination of population pressure and stagnating economic, social and technological conditions."[16]The degradation of forest ecosystems has also been traced to economic incentives that make forest conversion appear more profitable than forest conservation.[23]Many important forest functions have no markets, and hence, no economic value that is readily apparent to the forests' owners or the communities that rely on forests for their well-being.[23]From the perspective of the developing world, the benefits of forest as carbon sinks or biodiversity reserves go primarily to richer developed nations and there is insufficient compensation for these services. Developing countries feel that some countries in the developed world, such as the United States of America, cut down their forests centuries ago and benefited greatly from this deforestation, and that it is hypocritical to deny developing countries the same opportunities: that the poor shouldn't have to bear the cost of preservation when the rich created the problem.[24]Some commentators have noted a shift in the drivers of deforestation over the past 30 years.[25]Whereas deforestation was primarily driven by subsistence activities and government-sponsored development projects liketransmigrationin countries likeIndonesiaandcolonizationinLatin America,India,Java, and so on, during late 19th century and the earlier half of the 20th century. By the 1990s the majority of deforestation was caused by industrial factors, including extractive industries, large-scale cattle ranching, and extensive agriculture.Aims & ObjectivesForests are the lungs of the environment. They pump huge amounts of oxygen in the atmosphere which forms the basic need of almost all living forms on the earth. These forests are depleting day-by-day with an alarming rate. Human intervention is causing degradation and depletion of forests in many ways. Globally, every twenty minutes 1200 acres of forest are destroyed (Conservation International, 2000). Forest degradation is characterized by a reduction in forest quality and biomass by an opening up of the canopy (Joshi, 2006).Change detection is the process of identifying change in the state of an object or phenomenon by observing it at different times (Singh, 1989).It is extremely essential to monitor forest cover changes and find remedial measures to control deforestation after studying the reasons for forest cover depletion. Hence, detecting deforestation and other types of Land Cover Change (LLC) and determining factors contributing to it are important, as this could be a first step in controlling forest loss and is necessary in comprehensive forest management planning and formulation of appropriate forest policy (Grainger, 1993).Forest cover in hilly terrain is important from the ecological considerations. Recognizing this fact, the National Forest Policy (1988) aims at maintaining two thirds of the geographical area in hills of the country under forest and tree cover (SFR, 2009).

Need of DeforestationAt the current rate at which the rain forests are being destroyed, there will be no more rain forest in 30 years. In the last four decades, the demand for precious tropical hardwoods has multiplied nearly 25 times. People will continue to want them for furniture, woodworking and cabinetry, musical instruments, shipbuilding, and construction. Unfortunately, this means that the rain forests will not last unless something drastic occurs. Not only is the demand driving the extinction of the worlds rain forests, but so is the population increase in the tropics, the fastest population growth area in the world. In 1950, about 2.7 billion people lived in the world. In 2003, that many people lived in the tropics alone.Tropical hardwoods can only grow in a very narrow band of the world, and several of the most popular can only grow where the mean annual temperature is between 71 and 81 degrees Fahrenheit. They also need lots of rain, sometimes more than 6 feet per year. Except for the rain (which is not bad in Costa Rica, since it usually only happens for part of the day), most people would love to live where it is 75 degrees year round. People thrive where tropical trees thrive.Much of the deforestation has come from clear-cutting the forest to raise cattle for beef. (Cows like tropical temperatures, too.) Unfortunately, this is very short term, because clear-cutting causes massive loss of topsoil and degradation of the streams and the environment. Pretty soon, the land no longer supports cattle, because it has lost its fertility. Then the farm is moved to the next area, and another section of the forest is clear-cut. It is our craving for cheap beef that has created this cycle, and it is hard to be self-righteous when we understand that the people in the tropics are just trying to survive. Although growing tropical hardwoods is vastly more profitable than growing cows, you do not get any money back for at least 6 years, which is way too long if you need the money in order to eat.Another issue is the poaching of trees from the forests. Since a mature hardwood log can bring in two to three times the average annual income in Costa Rica, the temptation is enormous to cut whatever trees are left. Imagine the temptation to yourself if you could get more than three times your annual income by harvesting one tree! Many of the people who are poaching were loggers in the past. As it was their job to cut down trees, it is hard for them to understand that they shouldn't do it any more.Currently, 99% of tropical hardwoods sold are taken from virgin, old growth, tropical rain forest. Only 1 to 2% of the wood is currently harvested from plantations. This cannot continue much longer, or, as stated before, within a few more decades, there will be no more tropical rain forest from which to harvest.Presentation of Dataeforestation is ongoing and is shapingclimateandgeography.[27][28][29][30][31]Deforestation is a contributor toglobal warming,[32][33]and is often cited as one of the major causes of the enhancedgreenhouse effect. Tropical deforestation is responsible for approximately 20% of world greenhouse gas emissions.[34]According to theIntergovernmental Panel on Climate Changedeforestation, mainly in tropical areas, could account for up to one-third of totalanthropogeniccarbon dioxideemissions.[35]But recent calculations suggest that carbon dioxide emissions from deforestation and forest degradation (excludingpeatlandemissions) contribute about 12% of total anthropogenic carbon dioxide emissions with a range from 6 to 17%.[36]Deforestation causes carbon dioxide to linger in the atmosphere. As carbon dioxide accrues, it produces a layer in the atmosphere that traps radiation from the sun. The radiation converts to heat which causes global warming, which is better known as the greenhouse effect.[37]Plants removecarbonin the form ofcarbon dioxidefrom theatmosphereduring the process ofphotosynthesis, but release some carbon dioxide back into the atmosphere during normal respiration. Only when actively growing can a tree or forest remove carbon, by storing it in plant tissues. Both the decay and burning of wood releases much of this stored carbon back to the atmosphere. In order for forests to take up carbon, there must be a net accumulation of wood. One way is for the wood to be harvested and turned into long-lived products, with new young trees replacing them.[38]Deforestation may also cause carbon stores held in soil to be released. Forests can be either sinks or sources depending upon environmental circumstances. Mature forests alternate between being net sinks and net sources of carbon dioxide (seecarbon dioxide sinkandcarbon cycle).In deforested areas, the land heats up faster and reaches a higher temperature, leading to localized upward motions that enhance the formation of clouds and ultimately produce more rainfall.[39]However, according to the Geophysical Fluid Dynamics Laboratory, the models used to investigate remote responses to tropical deforestation showed a broad but mild temperature increase all through the tropical atmosphere. The model predicted