| The carbon balance(sink and source)has been a hot topic in the recent scientific research.Cities are an important place for human production and living and also a place which consumes a large amount of energy and releases a lot of carbon dioxide.According to the statistics,about four fifths of the world's carbon sources come from urban areas.Urban areas are a special component and one of the important links in the study of global carbon cycling.Meanwhile,the residential areas,as an important place for human activities,are also an important component of the urban ecosystem.The carbon sink and carbon source in the residential areas has a great influence on the emission and absorption of carbon dioxide in the urban ecosystem.This thesis takes Kunming as the subject of study,selecting the green plants in the residential areas as themain carbon sink and human social activities as the main carbon source.The estimation model of carbon budget was constructed by field observation,literature consulting,surveys and interviews.The author's aim is to quantitatively analyze the structural and changing characteristics of carbon sink and carbon source in different seasons and different residential areas,and identify the main driving factors that affect the carbon budget.The findings will help us to understand the driving effect of human social activities on the carbon cycling and provide scientific support for carbon management.These data and results may provide scientific basis for building low-carbon communities,green space systems of the residential areas in Kunming and improving the residential environment.The main conclusions can be drawn as follows:(1)From the perspective of space,the leaf area index,average photosynthetic rate,daily carbon fixation per unit leaf area and daily carbon fixation per unit land area of plants in Lidaojiayuan were higher than that in Fenglanguoji residential quarters.In terms of season changes,the leaf area index,average photosynthetic rate,daily carbon fixation per unit leaf area and daily carbon fixation per unit land area of similar plants in summer were greater than that in winter.(2)The total of daily net carbon fixation of afforestation plants in winter and summer were 75.29 kg and 185.17 kg respectively in Fenglanguoji residential quarters.They were 254.74 kg in winter and 452.14 kg in summer respectively in Lidaojiayuan residential quarters.The total of daily net carbon fixation in Lidaojiayuan was larger than that in Fenglanguoji residential quarters.The total of daily net carbon fixation in summer was greater than that in winter.(3)The total of carbon emission in winter and summer were 4719.95 kg and 4304.97 kg respectively,the total of per capita carbon emissions were 2.21 kg and 2.02 kg respectively,the total of carbon emissions per unit area were 0.24 kg and 0.22 kg respectively in Fenglanguoji residential quarters.The total of carbon emission in winter and summer were 5908.19 kg and 5375.90 kg respectively,the total of per capita carbon emissions were 2.16 kg and 1.96 kg respectively,the total of carbon emissions per unit area were 0.16 kg and 0.14 kg respectively in Lidaojiayuan residential quarters.In the carbon source structure,the carbon emissions of life activities in two residential areas are both the largest.The total of carbon emission in Lidaojiayuan was smaller,and the total of per capita carbon emissions was larger than that in Fenglanguoji residential quarters.The total of carbon emission,per capita carbon emissions and carbon emissions per unit area in winter were greater than that in summer.(4)In terms of carbon budget,the net carbon increment in winter and summer were 4644.66 kg and 4119.8 kg respectively,per capita carbon budget were 2.18 kg and 1.93 kg respectively,per unit area carbon budget were 0.23kg and 0.21kg respectively,the proportion of carbon source to carbon sink were 62.69:1 and 25.25:1 respectively in Fenglanguoji residential quarters.The net carbon increment in winter and summer were 5653.45 kg and 4923.76 kg respectively,per capita carbon budget were 2.07 kg and 1.80 kg respectively,per unit area carbon budget were 0.15 kg and 0.13 kg respectively,the proportion of carbon source to carbon sink were 23.19:1 and 11.89:1 respectively in Lidaojiayuan residential quarters.The net carbon increment in Lidaojiayuan were smaller,and the per unit area carbon budget and proportion of carbon source to carbon sink were larger than that in Fenglanguoji residential quarters.The proportion of carbon source to carbon sink in winter were greater than that in summer.(5)As far as factors influencing carbon budget are concerned,the major factors in carbon sink were light intensity,leaf area index and vegetation types while the density of population was the major factor in carbon source. |
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