The Research Of The Anti Freeze Disaster Ability Of Forest Ecosystem

The current management for the forest disasters main around to research the disaster warning and control. Warning means discover and take steps as soon as possible after alerm apprearing, in order to nip it in the blossom while not cause the disaster. Control means how to remedial and stop the disaster's further spread and expansion after disaster occuring. Those are the intermediate and post management for the disasters. To reduce the disaster incidence, the strongest weapon is reinforcing the self-defense ability to the disasters object and environment. Of course, prior management become the most effective measures. Therefore, the study of forest anti-disaster ability has very important practical significance.This article aims at the influence of different factors on the degree of analysis to identify key factors, and to guide future forest restoration measures to improve the forest's ability and prevent freezing. what is a reasonable regulation and protecting the existing forest resources and guidance to forest management is a great of significance. However, the affected individual has a forest area of?The hazards and their different characteristics, and that laws of the various regions of forest governance and control of anti-freeze is not the same.This article based on LiuYang city's forest ecological system, through researching to the related factors of the forest ecosystem anti-freeze disaster ability, that uses variety methods to screen main factors, and seeks relevant laws, and puts forward corresponding improving methods. The research details are as follows:1. This article uses two mathematical statistics-cluster analysis and multivariate statistical analysis methods to study the anti freeze disaster ability of forest ecological system, not only can quantify reflect the healthy condition of different types of forestland, but also can accurately reflect the influence of the main factor of the forest ecological system anti-freeze disaster ability. Compare with the analytic hierarchy process which be used a lot at present, the index weight calculation is more objective, and avoids the error caused by the subjective factors.2.This article based on the sample survey datas from the actual situation, through geography soil factor, forest stand factors and measure tree factors those three points to put forward the related factor of the forest ecosystem anti freeze disaster ability, this index system can reflect the anti freeze disaster ability of the different types of forest ecosystems of LiuYang city. And it easy to use, easy to operate.3.Through the principal component cluster analysis and multivariate statistical analysis methods, it prove the forest ecosystems anti freeze disaster ability is the interaction result between multiple factors. Through comparative analysing and assessing different forest types, and different plantation age forest ecosystems's snow disaster loss status, it prove that: the freeze disaster main happen in the height elevation; break is the common type of the freeze disaster, expecially stand out on the immature timber and ripe forest; the thin soil layer will worse turn over than the thick soil; the elevation is higher, the damage is more heavier; the windward mouth are worst-hit than the head wind mouth; the shady slope are worst-hit than sunny slope; the large steep hill be worst hit than the gentle slope; the forest will be worse damaged which have the large scale of small density stand and China fir; China fir and pine pure forest may worse hit than the other stand, thus it prove the mingled forest usual worse damaged than the pure forest; the exotic tree species are worst hit than the local tree species; immature timber and overmature forest are worst-hit.; the short trees are worse hit than the high tree; the width crown trees are worse hit than the narrow crown trees; the simple forest colony are serious hit. The main reason is that the structure of the mixed forest stand are complex. There are many mix undergrowth, and it with certain gradient relation between the forest's varieties of trees and height of trees, then the whole anti-snow pressure system be formed, thus it improves the anti-snow pressure ability of the mixed forest. At high altitudes, the large snow storms,low temperature,freeze injury make the snow breaking the wood more; while for the nearly ridge steep, the worse site condition the soil depletion,the shallow soil horizon the large wind and snow pressure may let the forest become top-heavy and then be root out, it easy to cause the turn pocket,conversely and other disasters; by the sun, the sunny slope with the high temperature, the snow melt faster, the forest be less snow pressure; for the large density forest stand, the big diameter trees with a large proportion, the slender tree stem, they anti-snow pressure ability are obvious worse; for the immature timber, it under high vigorous growth period, the tree stem with large taperingness, so the anti-snow ability is worse, the nearly ripe forest with the largest the crown diameter, so the snow pressure are also the biggest.4. through to analysis the affected situation, present the following six disaster recovery programs:①lead,select and plant cold resistant species;②clear the injury trees and plant new trees;③plant mixed forest, recover the forest ecological system structure;④proceed the forest transform, speed up the succession process;⑤strengthen the forest stand tending, maintain the ecological environment and heterogeneity;⑥pay more attention on the forest pest prevention.In the course of this article, the authors think it should be noted:①the modeling process should be to minimize the subjective nature of man:②model is based on the information that should come directly from the objective environment, that is taken from the survey data;③the premise of the loss of principal information, it uses dimension less as much as possible, but orthogonal to each other, independent new variables. At the same time, the resilience of forest ecosystems is not only reflected in the natural ecological level, but also reflected in other areas, such as many of our researchers advancing the social, economic and other indicators. This article has not yet set foot in these areas of research, which is also the research gaps. Hope that in future studies, can form a comprehensive evaluation system to quantify resilience.