Studies On Physiological Response Of Several Broad-Leaved Trees On Burning

This article used gasoline blowtorch on several coniferous and deciduous tree species simulated fire deal.The changes of each fire treated blades in physiological indicators were measured changes include of relative electrical conductivt, watercontent, sugar, chlorophyll fluorescence parameters. We analyzed of the fire instantaneity of physiological effects to the trees and changes of physiological indexes after fire a few time.We studied the microscopic point of view the impact of fire on plants.We compared the difference between the tree fire resistance from plant cytoplasmic membrane, antioxidant enzyme system, osmotic regulation system, chlorophyll fluorescence, moisture content in physiological aspects.Another we studied the recovery of physiological indicators after fire30d.We studied the recovery of physiological metabolism in burning trees. After burning the trees were subject to different degrees of damage, there would be a period of self-repair, if the repair was able to generate the compensation effect.It was very important to the application of prescribed fire, and promote the rapid growth of trees, as well as shorten the seedling in the choice of fire-resistant species.The main results of this study were as follows:1.It was the smallest damage to the cell membrane of Juglans mandshurica in upper trunk and lower trunk handle fire deal. It was the strongest in Faxinus mandshurica scavenging oxygen free radicals generated due to fire damage to the cell membrane.POD activity improved changed with trees and burned varies. The protein and proline content were the most improved in two burning F. mandshurica leaves.Fire resulted the decrease in three species chlorophyll content, which did not exhibit a certain regularity.It was the strongest recovery after the fire30d in F. mandshurica of antioxidant enzymes and osmotic adjustment substances contents.Phelodondrom amurense restored control levels of chlorophyll.2.The SOD and POD activity in Betula platyphylla were higher than in Quercus mongolica in upper part of the trunk and in the lower part of the trunk. The osmoregulation ability in Q.mongolica was hingher than in B. platyphylla after fire.After the fire30d, two species physiological indicators had been some recovery, but no consistent degree of recovery.3.The leaves produced by lipid peroxidation and the RWC, chlorophyll content and chlorophyll fluorescence parameters (Fv/Fo, Fv’/Fm’, qP, ETR) significantly decreased in0-10days after fire treatment. The antioxidant enzyme SOD activity, POD activity, proline content and soluble sugar content significantly increased, which showed the fire resistance of B. platyphylla. After10days of fire treatment, the damage began to recover and the content of MDA began to decline, the RWC, chlorophyll content and chlorophyll fluorescence parameter (Fv/Fo, Fv’/Fm’, qP, ETR) began to rise and reached control levels after30days of fire treatment. These showed equal compensation effects, and the content of MDA decreased to control level. The chlorophyll content and chlorophyll fluorescence parameters (Fv/Fo, Fv’/Fm’, qP,ETR) were significantly higher than control after40days of fire treatment, which showed super compensation effects. The increased leaf photosynthetic capacity repaired the damage by fire of B. platyphylla. The proline content and SOD activity were significantly higher than control, which was a delayed reaction and was beneficial for the growth of trees under stress.4.The effect in leaf membrane Pinus koraiensis more than Picea asperata in the upper half and the lower half of fires burning treatment After burning, the leaves of P.koraiensis and P. asperata had accumulated a large amount of proline, soluble sugar content also increased. Osmotic adjustment ability was stronger in P. asperata than In P. koraiensis.Fire resulted lower water content and chlorophyll content in P.asperata and P. koraiensis.The recovery showed no regularity after fire30d.5.The leaf membrane lipid peroxidation in Picea wilsonii Was less than in Picea asperata in he upper half of the trunk and lower trunk handle fire burning.The SOD and POD activity were greater in P.wilsonii than in P.asperata from antioxidant enzyme activity after two kinds of fire.The proline accumulation degree was greater in P.asperatathan in P. sylvestris from the osmotic adjustment after two kinds of fire.6.The extent of damage and lipid membranes were larged in the leaves of whole trunk fire than the roots in Pinus sylvestris.The SOD and POD activity of leaves were increased/The proline and protein content were significantly increased.Fire also led to decrease in chlorophyll content.After the fire30d, physiological indices returned to control levels.This illustrated the effect of fire on P.sylvestris was reversible and restored.After the fire30d, the SOD and POD activity increased and the proline content increased.