关键词: 桉树人工林, 冻害, 地理范围, 耐寒性, 中国南方

Abstract:

Eucalypt forest plantations were seriously subjected to a great catastrophe which was caused by heavy snow and freezing rain over eight provinces in southern China in early 2008. Afterwards，surveys were carried out to examine the severity of damage to eucalypt forest plantations and the tolerance of different species to the extreme low temperatures. It was found that the freezing disaster mainly happened to eucalypt plantations which were located in geographic areas with latitudes between 24°15′ to 26°54′ N and longitudes 104° to 118° E，and altitude from 300 to 600 m. however，the plantations were established in southern Hunan and Jiangxi and，those in northern Guangxi and Guangdong provinces，most seriously damaged. Individual trees in the plantations were mostly bent towards the ground or broken up by heavily accumulated snow or ice，the bark burst open and shots with foliage froze. Variation was also found in the ability tolerant to low temperature between different genotypes，for example，clone DH201-2 of hybrid Eucalyptus grandis×E. camaldulensiswas much less tolerant than clone DH32-29 of E. urophylla×E. grandis and GL9，a clone of E. grandis×E. urophylla，and E. dunnii and E. grandis were more cold tolerant as well. A caution was made that extreme temperature be carefully taken into consideration of strategy for developing eucalypt plantations in the future and potential risks exist in northward extension of planting areas.

Key words: eucalypt plantations, freezing damage, geographic areas, cold tolerance, southern China