Studies On Physiological Effects Of Burning On Trees

Quercus mongolica,Faxinus mandshurica,Phelodondrom amurense,Juglansmandshurica and Betula platyphylla, which are important trees in the northeastern area, havequite high economic and ecological value. Firing damage to trees in both side, but alsoconducive to the growth of trees side. At present, people adopt the way of planned firing,which shows that people have realized the advantages of firing. This paper studied fire's effectson trees' physiology and then studied firing's effects on trees' growth Through a fire test andfield sampling of physiological indicators, from which the fire-resistance physiological indexwas found, In order to offer scientific base for the choice of the trees that bear fire. Throughmeasuring the fired trees leaves physiological index and gas exchanging index, conclusionswere drawn as follows:1. The several studied factors of the directly fired leaves of trees, including the respectiveconductance, the contents of MDA, the activity of SOD and POD, and the contents ofPro, all increased to different extent.2. The changes of the physiological index of the new growing leaves after different firingtreatments are different from each other because of the different kinds of trees and do not havea certain rule.3. After burning, Pn of the new growing leaves all apparently increased in the three kindsof fire treatments of the following trees, F. mandshurica,Pamurense,J. mandshurica andB.platyphylla,, and the fire treatment of the leaves and branches of Q. mongolica, except thefire treatment of the stems of Q. mongolica.4. Samples from the open fields: the contents of the new growing leaves of the fired Q.mongolica, larch and birch apparently decreased, compared with the unfired trees. Theactivity of SOD and POD of the fired tree' leaves of Q. mongolica obviously increased, whilethe activity of SOD and POD of larch_and birch apparently decreased. At the same time, thecontents of Pro of the fired trees' new growing leaves of Q. mongolica, larch and birch allobviously increased.5. The study ensured that MDA is the fire-resistance index.