Study On The Material Properties Of Pinus Sylvestris Var.Mongolica In Different Fire Extents

Forest fire is one of the important factors in forest ecosystem,it can burn forests,pollute the environment,disturb the balance of forest ecosystem,but also can remove forest litter,release nutrients which storage in biological bodies and accelerate material circulation Of forest ecosystem.In this paper,Pinus sylvestris L.var.mongolica Litv.which growing in Honghuaerji Forestry Bureau burned area were took as test object,the material properties of different parts in the downed logs and burned trees and healthy trees of Pinus sylvestris were determined,and the pit structure of duct cells in xylem were observed under the electron microscope.The IBM SPSS Statistics 22 as the software analysis verified the experimental result analysis,effects of different fire degree on the material properties of Pinus sylvestris.The results are as follows:1.There were significant differences among the contents of organic extracts、the contents of the alkali extract、the contents of total cellulose、the contents of cid-insoluble lignin and acid-soluble lignin in the phloem of the downed logs and burned trees and healthy trees of Pinus sylvestris.2.There were no significant differences among the contents of organic extracts、the contents of ashes and the contents of pentosan of xylem in burned trees and healthy trees,and the contents of organic extracts、the contents of the alkali extract and the contents of total cellulose of parks between burned trees and healthy trees of.3.There were significant difference between the content of alkali extract,the content of lignin and acid insoluble lignin of the xylem in burned trees and healthy trees.4.There were significant difference in the contents of organic extracts of the xylem between the downed logs and healthy trees;There were no significant differences in the contents of acid-insoluble lignin between the downed logs and healthy trees.5.There were significant difference in the contents of acid-insoluble lignin、the contents of total cellulose and the contents of organic extracts of the xylem,and the contents of organic extracts、the contents of alkali extract and the contents of total cellulose of the parks between the downed logs and burned trees;There were no significant differences in the content of alkali extract of the xylem between the downed logs and burned trees.6.There were significant difference in the contents of hot water extract、the contents of Ash and the contents of pentosan,the contents of acid-insoluble lignin,the contents of acid-soluble lignin of the park among the downed logs、burned trees and healthy trees;There were no significant differences in the contents of acid-soluble lignin of the xylem between the downed logs、burned trees and healthy trees.7.The pit shape of condult cell of the xylem in the downed logs deformated,and the fungal hyphae winded the pit;The pit shape of condult cell of the xylem in burned trees was smooth and complete,was same with the pit shape of condult cell of the xylem in healthy trees,which proves that the fire was not damaged the pits of condult cell of the xylem.