A study on the freeze injury to trees in the area of Kunming in the winter of 1982

There was low temperature to-6.8℃(on Dec.21) that seldom occurred in the area of Kunming historically(at least for half a century).It damaged many trees,some 58 families including 180 species,however the injury was not serious.Among all the damaged trees,64% of them were slightly injured.The respondant degree of the vegetative parts of the trees to the low temperature,or the order of the damaged parts of the trees is from the leaf blade,to the annual shoot,then the biennial shoot,then the trinnial shoot,finally to the bole,and from the aboveground parts to the underground parts in turn.There are mainly two types of the morphological features of tho early freeze injury to the leaf blade,i.e.,litter spot and spot-piece.The blade is damaged from leaf flesh(vein islet) to vein,and from veinlet to thick vein.The freeze injury has close relations with the organic age,position and wooden level,in fact,it is virtually based on the water content.In this paper,the damaged condition of 180 species of woody plants in the area is recorded and it is preliminarily analysed from ecology anti florology.