造林模式对幼林期树种抵御极端寒潮能力的调控作用

[Objective]To actively respond to extreme climate change and explore afforestation modes that enhance the defense capabilities of young artificial forests against extreme low-temperature weather in southern China.[Method]This study focused on young forests of precious tree species planted after thinning in different low-quality and low-productivity artificial forests in northern Guangdong Province.By comparing the damage to four tree species in various transformation modes during different types of cold snaps,we investigated differences in frost resistance among tree species and their influencing factors in terms of cold snap characteristics,stand structure,and site conditions.[Result]In terms of cold snap characteristics,meteorological factors such as frost and strong winds occurring alongside temperature drops had a greater impact on tree species than temperature drops alone.There were differences in frost resistance among tree species.The species Castanopsis hystrix and Phoebe bournei,which are within their natural distribution areas,exhibited strong frost resistance.However,the species Eryrophleum fordii and Betula alnoidas,which were introduced northward from their distribution areas,were more affected by extreme low-temperature weather,with the degree of damage varying depending on the biological characteristics of the species.Tree species with lower cold resistance faced a higher risk of damage in clear-cutting afforestation modes compared to interplanting modes.Among various interplanting modes,the degree of damage to interplanted tree species increased as the retention density of the overlying stand decreased and as the forest gap area increased.Additionally,the shape of the forest gap had a significant impact on the degree of damage.Topography also had a noticeable effect on the degree of damage to tree species,with windward slopes such as north-facing slopes experiencing much greater damage than leeward slopes such as south-facing slopes.[Conclusion]The development of precious tree species requires a scientific and reasonable selection of afforestation modes based on an understanding of tree species adaptability.When introducing precious tree species northward from their distribution areas,the potential impact of extreme low-temperature weather should be considered.Maintaining a certain stand environment can effectively enhance the defense capabilities of these species against extreme low-temperature weather.The results of this study provide valuable insights for the cultivation of artificial forests and the improvement of forest quality in regions with frequent cold snaps.