Effects Of Air Quality On Carbon Fixation And Oxygen Release Of Common Tree Species In Beijing

In recent years,Beijing and other places are strengthening intensity to the haze governance,the frequency and intensity of heavy pollution weather is being declined,but it still do not meet the air quality standards in China.Domestic research about the relationship between haze and plants are mainly concentrate on the dust retention effect of urban plants or plant communities,but has lack research on the poor quality air's effect on the carbon fixation and oxygen release of plants.This paper takes the main greening tree species in Beijing city as the research object,on the basis to ensure the consistent environmental conditions,using test and analysis as research method,we study trees photosynthesis rate and carbon fixation and oxygen release in haze weather conditions,indicate the air pollution status on the common green tree,provide the scientific basis for city greening tree species selection,but also enrich the content of environmental biology.The result shows that:(1)On net photosynthetic rate showed a single peak curve of Jin Yinmu,Liriodendron,Sophora japonica peach,cherry and peach six species;Magnolia Tilia,Begonia,hawthorn,Prunus lannesiana and four plants showed the flowering plum Shuangfeng curve.(2)The carbon fixation and oxygen release ability of the common greening tree species in Beijing changed with season,and the common greening tree species tended to carbon fixation and oxygen release capacity in summer.(4)The common green tree trees per unit area of carbon fixation and oxygen release total order:>Begonia peach honeysuckle>the Japanese late cherry,>Liriodendron,>hawthorn,>Magnolia,>linden,>flowering plum Sophora japonica f.pendula;unit land area greening trees throughout the year the total carbon fixation and oxygen release order:Honeysuckle>prunustriloba Petai>Prunus lannesiana Hawthorn Begonia peach>cherry Tilia Magnolia>Liriodendron Sophora japonica.(5)The unit leaf area of carbon sequestration and oxygen release efficiency is the highest index of carbon fixation and oxygen release and 19.83 yuan per unit land area;carbon fixation and oxygen release efficiency is the highest and carbon fixation and oxygen release and 111.12 yuan.(6)With the decrease of air quality,the carbon fixation and oxygen release capacity of green tree species decreased in different degrees.The tree species in the most affected degree is Linden,the smallest is yulan.It shows that magnolia can still achieve good ecological effects of carbon fixation and oxygen release when air quality drops.It is not affected by air quality.Linden is affected by the serious impact on air quality,air quality decline,the loss of 34.37%Linden carbon sequestration and oxygen release.(7)The characteristic factor of gas exchange:correlation between stomatal conductance and steam rate and air quality,the air quality and the two factors were proportional to the logarithm of R2 was greater than 0.95,with a significant correlation.(8)Decreased when the species of carbon fixation and oxygen release capacity of the decline in air quality,23%-16%leaf surface is due to gas exchange caused by the decline in the rate of disgraceful and hinder the light induced,most of the rest is due to the ambient light led to a decline in plant photosynthesis weakened.(9)In order to maintain the common greening tree species of carbon fixation and oxygen release ecological benefits,eliminate the lower air quality impact on the quality of city environment,and should improve the Magnolia honeysuckle green ratio.