Document Type : Research Paper
Growing process of industrialization in different societies, excessive expansion of industries and factories and increase transport industries, push human toward unstable development. Among these problem, massive volume of pollutions is also added to the atmosphere. Air pollution in industrial societies and cities is more intensive. Global warming is one of the major problems of 21 century. CO2 diffusion dangers in different global environmental societies has emphasized and combatting ways to that has thought. From the beginning of industrial revolution, fossil fuel burn and deforestation leads to increasing atmospheric CO2. Global warming may leads to changes like change in raining patterns, sea level expansion and wide spectrum of influences on plants, wild life and human. Gases that trap heat in atmosphere are named greenhouse gases. Existing proofs show that human activities, can increase atmospheric ability to conserve heat (greenhouse effect) and result to climate change (global warming). Increase greenhouse effects results from increase in CO2, CH4 and NOx of human activities that trap oxygen and increase temperature of the earth. These gases are include: CO2, CH4, NOx and CFC that CO2 content is more than others. (farag and others,2007) different effects has presented for greenhouse gases till now. The first effect is the effect that cause probable increase heat as a result of absorption infrared photography . Urbanity and urbanization is as one of the important land use in 21 century that according to anthropogenic reasons rapidly growing in other ecosystems. 50 percent of world population are living in cities that this process rapidly growing. Based on anticipations, urban population will reach 70 percent in 2050.urban areas, because of rapid population growing has passed from agricultural land use. Urban growing in different social, economic, political and ecologic areas leads to decrease ability of cultivated areas to produce enough foods for world population. Growing big cities leads to use of sources like energy, minerals, fuel, water, food and production great sources of sewage and scrap. This intensive ecological form and extreme use of natural sources as an important anthropogenic motivation leads to global continent change. Continent change is one of the important problems of permanent development that can have negative influence on marine and land ecosystems. Main sources of CO2 and other greenhouse gases in urban ecosystems imputes to industry and transport systems in this areas. Bad weather quality in millions of cities resulted from effluence of wide range of gases from industrial sources. In compare to rural areas, also there is more density of CO2, CH4 and ozone in urban cities. Air pollution effects on primary network of production and indirectly influence on GCC. Worry from mass volume of emitted carbon in atmosphere and its effects on continent, human and ecosystem functions continuously increase. As after these worries, in 1992 approximately all of world countries include Iran sign a convention as United Nation Continental Changes Convention that aimed to find a course of actions to balance out volume of atmospheric greenhouse gases and predict budget for this purpose and to search and survey around this problem in member’s countries of this convention in long term. Pursuant that convention, another pact in 1997 in Kyoto approved by most of industrial developed countries at which countries undertook to find solutions to balance out container of atmospheric greenhouse gases. Most suitable mentioned solution which can decrease atmospheric carbon is carbon sequestration by forests, pasture, woodland and soil. Carbon sequestration is long time storage of carbon in surface, underground or oceans in the way that decrease CO2 volume ( main greenhouse gas) of the atmosphere. Carbon sequestration in plant biomass and soils around this biomass is one of the cheapest and simplest ways to decrease CO2. Dominant vegetation cover is one of the important and effective factors in stabilization and carbon sequestration in ecosystems. Differences in vegetation diversity physiology determine absorbed carbon rate, rate of carbon transmission to the soil and loss of carbon in ecosystem. Consequently, animate and inanimate factors can determine absorption rate, stabilization rate, scale and speed of energy flow I an ecosystem by influence on vegetation diversity. Increasing CO2 and other greenhouse gases in atmosphere is the main reason of climate change. In metropolitans especially because of dense volume of industrial activities, these gases leads to pollution. Increase density of CO2 and other greenhouse gases in atmosphere are the major causes of climate changing. Intensive industrial activities especially in metropolises, can increase this gases and lead to pollution Carbon storage in the soil is one of different methods to sequestrate atmospheric carbon and preventing pollution. Storing carbon in soil is one of the different ways to trapping atmospheric carbon and reducing pollution. This study is aimed to evaluate the soil carbon storage in herb, shrub and tree covers in human made usage (city) include boulevard, urban park, industrial areas, house gardens and in agriculture, garden and pasture usages. For this propose, in the area at the west of Shiraz, from depth of 0-10 and 10-50 of mentioned usages, sampling has done in systematic random way. Statistical analyses has done based on completely unequal random pattern in the form of factorial design. Results showed that, SOC sock under tree and shrub covers in compare to herb has a considerable increase. Also cultivated gardens with 3/8 t/h carbon stock has considerable increase in carbon sequestration in compare to other land usages. According to results, increase wooding beside other covers and changing land use like changing arid land and destroyed pastures to cultivated gardens in long time can lead to increase soil carbon stock.