Analysis On Fire Resistance Of 15 Tree Species In Hohhot

Garden plants play an important role in purifying air,reducing urban heat island effect and beautifying environment.Landscape plants are the main body of urban environment,and the fire resistance research is an integral part of fire prevention and disaster avoidance of green space evaluation.Hohhot got rich resource in garden plant,and also has strong regional characteristics,it has significant advantages in the development of biological fire prevention research.In landscape architecture,the fire resistance of plants can be adjusted by screening tree species,selecting tree species with strong fire resistance to form a "Green Barrier" area could reduce fire spreading and regulate the comprehensive fire resistance of landscape,so that it will reduce the risk of urban garden fire and also provide basis for identifying high-risk landscape.This thesis takes Hohhot as the research area and selected15 kinds of arbor tree species as the research object,by using experimental analysis,fitting analysis,principal component analysis method to get the comprehensive fire resistance capability of 15 arbor tree species via experimental analysis of the biological,ecological,physical and chemical properties and pyrolysis characteristics of functional leaves and branches of arbor species,and ranking the 15 tree species by grade classification,and finally provide the theoretical basis for the selection and planting of high-quality fire-resistant tree species and the safe green ecology construction.Conclusions are as follows:1.Through the investigation,research and evaluation on the biological and ecological characteristics of the 15 garden plants,the order of fire resistance is as follows: Morus alba,Chaenomeles,Betula platyphylla,Padus racemosa,Armeniaca sibirica,Sophora japonica,Acer ginnala,Quercus wutaishansea,Acer truncatum,Sabina chinensis,Platycladus orientalis,Picea meyeri,Pinus bungeana,Pinus armandii and Pinus tabuliformis.2.The study of the internal physical and chemical properties of tree species shows that: There are obvious differences in water content,ash content,calorific value,ignition point and ignition time indicator among the tissue and organ of arbor tree species.The experiment result shows that the moisture content of leaves is higher than that of branches and so is the ash content;The calorific value of each arbor tree species is about 38 MJ·kg-1;The burning point of the garden tree species organ is relatively stable,concentrated at about 110?except cherry-apple tree.Considering the two organs of arbor tree species to fix the 5 index weight,including absolute dry moisture content,ash content,calorific value,ignition point and ignition time by using principal component analysis to screening the tree species with strong fire resistance are Sophora japonica,mulberry,cherry-apple tree,apricot and Acer truncatum.3.To study and research the weight loss behavior of 15 tree species by thermogravimetric analysis from the aspects of thermogravimetric rate and thermogravimetric rate curve,the result shows that the pyrolysis reaction of the samples in air atmosphere is characterized by water analysis period,rapid pyrolysis period and carbonization period.Based on the index analysis of thermal stability and pyrolysis characteristic of the organ,leaves and branches of arbor tree species,the tree species with strong fire resistance were selected as: Sophora japonica,Morus alba,Chaenomeles,Armeniaca sibirica,Acer truncatum,Acer ginnala,Padus racemosa,Betula platyphylla,Quercus wutaishansea,Platycladus orientalis,Picea meyeri,Pinus bungeana,Sabina chinensis,Pinus armandii,Pinus tabuliformis.4.According to the biological,ecological,physical and chemical properties and thermogravimetric behavior of arbor tree species,the fire resistance of 15 tree species was ranked from strong to weak as follow: Morus alba,Chaenomeles,Sophora japonica,Armeniaca sibirica,Acer ginnala,Acer truncatum,Betula platyphylla,Padus racemosa,Quercus wutaishansea,Picea meyeri,Platycladus orientalis,Sabina chinensis,Pinus armandii,Pinus bungeana,Pinus tabuliformis.5.The result shows that these tree species Morus alba,Chaenomeles,Sophora japonica,Armeniaca sibirica,Acer ginnala,Acer truncatum have strong fire resistance and could be selected as "Green Artificial Barrier" among the 15 arbor tree species.The results provided theoretical basis for the construction of high-quality fire prevention forest belt in Hohhot.