Research On The Sensitivity Of Roadside Typical Plants To Vehicle Exhaust

Subject: Research on the Sensitivity of Roadside Typical Plants to Vehicle EmissionsMajor: Vehicle Operation EngineeringSupervisor: Professor Shiwu LiIn construction of road filling and excavating destroyed the surface layer soil, and has made rock exposed, which has seriously affected the original vegetation of restoration. The slope where no vegetation is easy to receive washout because of the rain, and which arises the soil erosion or the unstable slope harm. The former people u-sually make sure the slope stability or no erosion by protective project, but recently with the people environmental protection consciousness enhancement, in the world more and more countries began to pay attention to highway biotechnique and emphasized the deference nature, melting in the periphery environment, restored the original natural vegetation and the landscape as far as possible, embodiment the ecology and environmental protection consciousness.At present, the road ecological restored technology has developed to a zoology combined with sight system. It emphasized the road planting which should overall evaluation ecology function,the landscape beautification function,the peripheral environment coordination function,the transportation attached facility function and so on. The perfect union causes the highway construction and the nature mergeing into a harmonious whole. These days, the virescence vegetation useed for zoology comeback are almost what are able to endure leanness ones and strong adaptability local plants or which can't bring other species invasion of plants from abroad. The vegetation suffer from many severe influences, for example: there is short of water on field and nobody takes care of them, and dig and fill in the road construction have also aggravate the environment or decrease nutrition of soil, moreover the vehicle exhaust in road transport has the bad influence to the vegetation. Therefore, not only the temperature,the moisture,the sunshine, but also the exhaust gas of vehicles has influenced the comeback of ecology at roadside. Because of the exhaust emissions,the leak gas at crank case,the evaporate of fuel from traveling vehicle produce lot's of poison gas, such as: nitrous oxide(CO), hydrocarbon(HC), nitrogen oxygen compound(NOx),particle and so on. Such poison gas enters the plant through air hole at leaf. After the noxious gas enters the plant organization, they could disturbed the function of enzyme, hindered plenty of metabolism. At the same time, the virulent material also may further decompose or take part in photosynthesis, produces the new deleterious substance.further aggrieve the cell and the organization of the plant, bring up further damage. Becauseof the very effect of the vegetation in the road ecology stable, so that it's vital to find the strongest resistance exhaust vegetation.In the article vegetation in the exhaust fume experiment is mainly from a section of highway of Jiangyan, analyzing the growth index and physiological index during and after the exhaust fume experiment, and then finding out the most resistant vegetation to exhaust.First, according to the design traffic of the freeway of Jiangyan, and we computed the force of source from the exhaust. And based on the uprightness of the wind direction and the road, roadside exhaust density is to the greatest, evaluating it.The result indicated even if this kind of exhaust achieved to the greatest density, there is little bad effect to the vegetation.Therefore it's impossible to make sure roadside vegetation resistant to observe its growth. So it's effective and immediate means to find the best resistant vegetation by fast fumed experimentation.And then, make sure the acute injury threshold value to determine the density of the fume examination.The general expression formula of injury threshold value is: Density×Time. We increased exhaust fume and reduced the test time to receive threshold values of several egetation and make the minimum value as the present threshold of all the plant.At last, take the examination according to the test outline.make sure the growth index, after the examination we analyse the growth index of four plant according to the synthesis growth target appraisal law,the multi objective quality synthetic evaluation law,endures patiently the exponential method and the acute injury performance symptom law. has carried on the quality synthetic evaluation to four kind of plants.Through this article research analysis,All uses smokes greatly was mad the density reduction smoked was mad the time the means obtain several kind of plant's threshold values, chooses minimum value to take all plants the threshold value then basis already determined the experimental plan carries on smokes is mad processing, the determination growth physiology target, after all experiments had ended carries on the growth physiology target the analysis, then used the synthesis growth target appraisal law, the multi objective quality synthetic evaluation law, endures patiently the exponential method, the acute injury performance symptom law has carried on the quality synthetic evaluation to four kind of plants.Through the research, make the contrast between the data from plants in normal process and the data from plants in the different stress of exhaust. After research to analye the datas of the growth index and physiological index, the result is that the best resistant plant is zisuihuai, in the next place is spiraea,white orpine and yellow orpine in four kind of typical vegetations from jiangyan highway.This paper research the influence from vehicle emissions to vegetations, we not only chose the physiological index but also to choose the growth index to carry on the appraisal to the plant, and make sure the plant's injury threshold through further research, which make shue the research content more perfect, and the result is near to reality. The research achievement will provide the reference use for the vegetation grow at roadside.