The Research On The Frost Damage And Germination Rate Of Eucalyptus In Huanjiang County,Guangxi Province

Guangxi is China's largest area of eucalyptus plantations provinces,in recent years,the eucalyptus develops northward and to higher altitudes,making it suffer the higher risk of the low temperature damage,especially frost damage.However,We still lack the sufficient knowledge and comprehensive understanding about such situation.On31th,Dec,2018,Guangxi Huanjiang Maonan Autonomous County suffer low temperature and freezing rain,making young eucalyptus stop growth.This research regard different month of growth of the eucalyptus as samples,conducting a comprehensive survey on the extent of the disaster and post-disaster affected germination rate,analyze the data and show changes in ground diameter,forest age,elevation,slope direction,slope and frost damage index and germination rate,demonstrate that the relationship of biological factor,topographical factors with frost damage and germination rate,the conclusion showing below.?1?From 31th,Dec,2018 to 3^rd,Jan,2019,the duration of low temperature and freezing rain makes the growth of eucalyptus?4 months to 18 months?from the altitude 400 to the altitude 900 suffer severe frost damage,of which the extent from moderate to severe.?2?The forest age and ground diameter have significant effects on the degree of frost damage and post-disaster germination rate.The forest age and ground diameter of the stand were significantly negatively correlated with the freeze damage level and the freeze damage index,and showed a significant positive correlation with the post-disaster germination rate.the increase of the forest age and ground diameter is conducive to enhancing the anti-freezing ability of the eucalyptus and improving the germination ability after the disaster.?3?The elevation,slope direction and slope of the woodland also have a significant effect on the degree of frost damage and post-disaster germination rate.In general,there is a significant positive correlation between altitude and the degree of freezing damage of Eucalyptus,and a significant negative correlation with post-disaster germination rate.There was a significant positive correlation between the slope and the degree of freezing damage of the Eucalyptus,but a significant negative correlation with the post-disaster germination rate.From gentle slopes to steep slopes and steep slopes,the degree of freezing damage was significantly enhanced,and the germination rate after the disaster was significantly reduced.?4?According to the research,the afforestation of Eucalyptus should be avoided the altitude of above 500 and the slope degree from 30to 40.Although the germination rate is 88.67%in the affected forests with4-18 months of forest age,the average germination rate can reach 88.67%.However,further research is needed to be made whether it can be free from the disaster it has suffered.