Table of Contents
The destruction of wetlands in the early years has resulted to major disasters in the modern days. This has led to the realization of the importance of wetlands and rehabilitation is taking place. The major benefits of wetlands to the ecosystem benefits include flood control, water purification, ground water replenishment, climate change mitigation and adaptation and others as discussed in the main text. The effects of deforestation are categorized as environmental and economic effects. The environmental effects include soil erosion, disruption of the water cycle, loss of biodiversity, climatic change flooding and drought (International Institute for Environment & Development, 1996). Soil erosion results from the soil exposure to the sun, thereby making it very dry and eventually infertile. These and other cases are fully discussed in the paper together with their mitigation measures.
Environmental Impact of Wetland Destruction and Deforestation
A wetland is an area of land covered with water, which may be permanent or seasonal, the covered area adapts some distinct characteristics separate from any other ecosystem. These distinct characteristics are the vegetation, soils and water. The vegetation is purely aquatic and the soils are hydric (International Institute for Environment & Development, 1996). The water can be saltwater, freshwater or brackish and the plants will adapt to the water type. A wetland can be naturally occurring or be a constructed one. Constructed wetland is mostly established for wastewater treatment processes. They are highly adapted to treating of raw sewage, domestic sludge, mining wastes and industrial and agricultural effluents. The effluent flows in a series of ponds which have special plants and microphytes. It should be noted that the functions of a natural wetland and an artificial wetland vary greatly (Boersema, 2010).
There are four major types of wetlands which include swamps, marshes, bogs and fens. Examples of the major wetlands of the world include the Amazon basin, the Pantanal, and the West Siberian lowland (International Institute for Environment & Development, 1996).
It is also worth noting that the following rivers form wetland in their course to avoid flooding: the Nile river in Africa, the Mississippi river in the U.S.A, the Amazon river in South America, and the Yangtze river in China among others (Boersema, 2010). These wetlands will normally vary greatly in their characteristics. These variations are caused by differences in topography, hydrology, the vegetation and human activities present in a specific wetland.
The various wetlands of the world are distinguished from each other based on the hydrology. water type. salter or fresh wetland, the soils and their characteristics including the mineral composition, the biota and fauna and the algae composition. These characteristics distinguish the various wetlands of the world like those occurring in the shorelines and those found in the inland and define the environmental importance of that specified wetland in relation to the environment where it occurs (International Institute for Environment & Development, 1996).
The major benefits or functions of wetlands are lean more in the ecosystem benefits than the economic benefits which may be realized by conversion of a wetland into agricultural land. The ecosystem benefits include flood control, water purification, ground water replenishment, climate change mitigation and adaptation, home to flora and fauna, shoreline stabilization and storm protection (Hancock, 1999). The wetland will control flooding in the rainy season and communities downstream will be saved from the effects of flooding. The effects of flooding are being experienced in the communities which converted their wetland into arable land which leads to property destruction and loss of lives by flood water, evident in many parts of Africa and Asia (Liotta & Kepner, 2008).
On water purification the wetlands filter chemicals from fertilizers and pesticides used in agricultural fields upstream to neutralize their effects, the wetland will also oxygenate the waste to help in sustaining the lives of aquatic animals like fish (Hancock, 1999). Ground water replenishment is another important function of the wetland, naturally occurring wetlands allow water to infiltrate to the underground replenishing the underground storage, this process is gradual and it is designed to supply enough water all seasons even when there are no rains. The ground water is later harnessed by the drilling of boreholes and wells which account to over 50% of the human water supply both in domestic and agricultural sectors (International Institute for Environment & Development, 1996).
On shoreline protection, the mangrove which usually grows on the shoreline will reduce the speed and height of waves and flood water during the storms. The mangrove will normally migrate to the shoreline on different periods to remain adjacent to the boundary with water (Hancock, 1999). The economic benefits derived from the wetland ecosystem include wetland products like medicinal herbs, recreational, tourism and the cultural values associated with wetlands. These economic benefits will earn the country or community some revenue though overexploitation should be avoided (Liotta & Kepner, 2008).
Environmental Effects Resulting from Wetlands Destruction
Human life cannot exist without the interactions of the species in biological systems, yet we live in a period of the greatest loss of plant and animal species since the historical extinction of the Jurassic period 65 million years ago. It is estimated that 50,000 species of animals and plants disappear each year due to expanding agriculture, tropical deforestation, and human settlement among others. Human activities have a great impact on the environment including clearing agricultural land, massive land air and water pollution, urban and suburban development (Boersema, 2010). Environmental impact of wetland destruction includes reduced water quality, increased floods, depletion of underground water storage and supply, loss of bio productivity and natural habitat for millions of animal species, loss of economic and financial aspects, missed recreational and cultural opportunities associated with wetlands (National Research Council, 1987).
Wetlands filter and retain significant percentages of nitrates such as ammonium phosphorous and sediment loads. Natural wetlands are also effective in removing contaminants such as pesticides, landfill leachate and dissolved heavy metals from water runoff and chlorinated compound. The destruction of wetlands has resulted to the effects of the above pollutants causing harm to the ecosystem and the humans at large. The presence of wetland greatly reduces the effects of flooding in the inland. Several hurricanes have resulted in loss of lives and destruction of properties worth billions of dollars in the USA. A good example is the 2005 hurricane season where the Gulf coastal landscape and associated infrastructure were crippled by wind, tidal surge and floods. In 1993 in the USA the Mississippi river flooded causing infrastructure damage estimated to over $16 billion. A study by the Wetland Initiative showed that the rehabilitation of the 100 year flood plain in the upper Mississippi would increase the storage capacity of the wetland to 39 million acre feet of flood water which is equivalent to the volume that caused the flood damage (International Institute for Environment & Development, 1996).
Wetland ability to recharge the aquifers is another great benefit of maintaining our wetlands. Boreholes drilled in the early 70’s have dried due to declining water table. The small wetland of the USA or the plays are useful in recharging the Ogallala aquifer which provides groundwater used for agricultural purposes and also provide drinking water in the plains (Liotta & Kepner, 2008). Mixtures of vegetation and shallow water zones provide habitats for a variety of plants, insects, amphibians, reptiles, fish, birds, shellfish and mammals (Hancock, 1999). These species rely on the wetlands for survival and derive their food, shelter and breeding grounds from it. Interference and destruction of wetlands have resulted in the extinction of many of these species in many parts of the world (Boersema, 2010).
There are many commercial products harvested in the wetlands such as rice, peat, hay, timber and medicinal herbs. The coastal wetlands provide buffers that protect the commercial and industrial infrastructure which include ports and oil and gas processing structures. Without the wetlands the above infrastructure will be rendered absolute in a few years.
The recreational and cultural opportunities are the major source of revenue and it is estimated that 82 million Americans took part in recreational activities in 2001 spending approximately $ 108 billion. Without proper utilization and maintenance of the wetlands the local governments will end up losing millions of dollars in revenue (National Research Council, 1987).
Forests and Their Environmental and Economic Importance
Forests are defined as areas of the world covered with trees. The tree cover of the world is currently at 30% though originally the forests covered 50% of the earth. This is as a result of continued deforestation, land degradation and human encroachment among other factors (Hancock, 1999). The classification of the forests varies and the following classifications are accepted worldwide: hardwood or softwood forests, natural or man-made forest or classified according to the variation in ecosystem and the biomass that exist in them such boreal forests, temperate forests, tropical and subtropical forests. The boreal forests are evergreen and coniferous, they occupy the subarctic zone. Temperate forests support both the broad-leafed deciduous trees and the evergreen coniferous forests. The tropical forests include the moist forests, the dry forests and the coniferous forests. The dominant climate and the major characteristic of the tree cover area used here to derive the above classification through tree physiognomy, which classifies forests based on the physical structure and overall tree development stage (National Research Council, 1987).
The importance and use of forests are many and human beings come to direct or indirect effects with products of forests every day. The following are the major benefits of the forests and prove why we need to conserve our forests. Forests are the only natural air purifiers, they absorb the carbon dioxide we excrete and convert it into oxygen which we need for breathing and lighting. This shows that without trees and vegetation human beings would find it hard to exist. Forests retain massive amounts of water during rains preventing runoffs and soil erosion. The retained water is allowed to seep into the ground slowly, hence recharging the underground water storage which keeps our rivers flowing all seasons and makes sure our wells and boreholes do not run dry during the hot weather. The effects of deforestation have been worst felt in the world with rivers drying up and massive loss of fertile soil due to erosion and common flooding (Boersema, 2010).
Forests are the habitants of biodiversity. Forests are homes for millions of animal species ranging from insects, animals, bacteria and fungus among others. The species find their food and shelter in the forest and are protected from extinction. Forests are also valuable for humans since they are a source of food and some of the tree species have medicinal values. Scientists have searched the forests for specific herbs which have curative qualities and this has led to the discovery of new medicines to the advantage of human beings. The forest communities have also found refuge in the woods over the years (National Research Council, 1987).
The economic importance of forests is endless from the timber which we use in our homes and offices to the tourist and recreational sites that the forests offer to boost our national income. Forests also offer the best sites for movie and cinema production. Other uses vary from one forest type to another like the mangrove forest which protects the coastal line from the effects of tidal waves during storms, the wetland forests which will purify the waters and add nutrients to the water (Hancock, 1999). These and other benefits show why we need to conserve our wetlands and forest cover. The effects of neglecting and abusing the wetland and forests through human activities like deforestation, conversion, encroachment are resulting in massive environmental degradation and this is being witnessed by loss of biodiversity, flooding, climate change among others (National Research Council, 1987).
Environmental Impact of Deforestation
Deforestation is caused by multiple factors. Most of these are short-term economic factors characterized by corruption in government institutions, wealth and power as people scramble for the resources offered by the forests, rapid increase in population growth and urbanization is the major cause of deforestation in the countries. Urban construction is one of the leading factors of deforestation. As we erect new structures, we cut down trees to be used as building materials, furniture and paper products. Urbanization has also led to clearing of the forests to accommodate expanding cities and villages resulting in massive deforestation (Hancock, 1999).
Search for arable land is also a result of deforestation as people clear forest to grow crops and build ranches. Areas cleared of forests are considered virgin lands and have high amounts of nutrients which produce huge harvests on the first years of cultivation. Grazing land is the factor leading to deforestation as people clear forests looking for grazing fields to sustain their huge herds of animals. Overgrazing and overstocking usually go hand in hand as greedy farmers try to maximize their profits with few resources. This is evident in the African continent where huge parcels of land were cleared in the 1980’s to allow the pastoralist communities expand the farming activities (Clare, 1990).
Firewood and charcoal burning as communities search for fuel is another factor. This is mostly done in developing countries as firewood and charcoal are the farm sources of fuel for cooking and heating purpose. The emergence of commercial charcoal burners resulted to massive deforestation as the businessmen tried to maximize their profits by producing more charcoal and firewood without consideration of the environment. There are other commercial activities that are attributed to deforestation such as clearing of forests to build highways and roads, oil and mineral exploration, slash and burn farming techniques and acidic rain. This leads to loss of forest cover which is the home to the wildlife resulting in the extinction of our beloved animal specifies (Hancock, 1999).
The effects of deforestation are categorized as the environmental and economic effects. The environmental effects include soil erosion, disruption of the water cycle, loss of biodiversity, climatic change, flooding and drought. Soil erosion results from the exposure of the soil to the sun thereby making it very dry and eventually infertile. The soil loses its nutrients such as nitrogen and when the rain falls, the topsoil and nutrients are washed away since there is no vegetation to hold the runoff which sweeps away the fertile soil with it.
The loss of diversity is the other key environmental effect of deforestation. Around a 100 of animal species and plants are lost everyday due to deforestation in the tropical rainforests. The animal species do not only lose their habitat and the protective cover but they are quickly facing extinction (Clare, 1990). The forest cover maintains the water cycle by drawing ground water with their roots which is then released to the atmosphere. A large part of the water that rotates in the rainforests is held up by the plants and when cut down the climate around that area dries up. The trees prevent runoff water and aid the soil in absorbing the water, hence maintaining the desirable levels in the water table. When the trees are cut runoff is rampant resulting in depletion of the underground water resources (Liotta & Kepner, 2008).
The climatic changes result when during deforestation the trees are burnt down or allowed to rot which results to release of carbon that is stored in the trees as carbon dioxide. This results to a greater concentration of carbon dioxide in the atmosphere which causes global warming. Trees are the major store for carbon dioxide as they absorb carbon dioxide from the atmosphere and use it to produce carbohydrates, fats and proteins which make up the trees (Clare, 1990).
Possible remedies include: for every tree cut we should plant three, water catchment areas should be strictly isolated from human being, strict laws governing deforestation should be enacted globally, planting of fast growing trees such as exotic soft woods for the commercial industry and lastly diversification from wood and charcoal as the main sources of fuel and embrace renewable energy sources such as wind and solar which are clean energy sources.
A case study of Brazil shows the full magnitude of deforestation. A few decades ago Brazil had more than 600,000 square kilometers of forest but most of it has now been lost due to deforestation. Brazil constitutes around 60% of Amazon rain forest which makes its attractive for exploitation. By 2006 Brazil had lost more than 150,000 square kilometers from the initial 600,000 square kilometers in the 1970’s (Boersema, 2010). This area is equivalent to the total area of Greece. This destruction resulted from overgrazing or search of pastures where farmers with thousand of cattle let them graze at the forest destroying the leaves and stems of trees which they feed on. Another factor is the human activities where humans collect rubber in large quantizes destroying trees. This has resulted to the loss of valuable species, desertification and global warming (International Institute for Environment & Development, 1996).
Zimbabwe is another example of a country that has lost its forest cover due to deforestation. Land clearance for search of arable land constitutes the biggest factor of deforestation in Zimbabwe where it is estimated that 23 million hectares are lost annually (Clare, 1990). The economic imbalance and poor governance contributed much to the deforestation with the oppressed poor putting pressure on the environment as a survival tactic. This has resulted to heavy flooding, soil erosion and imbalance in the ground water supply mechanisms.