土壤增温隔水处理对杉木幼林材管胞形态的影响

Effects of Soil Warming and Precipitation Exclusion on Tracheid Morphology of Young Chinese Firwood

采用地下管道进行土壤增温5℃与透明U型管隔离降水50%的方法,人工模拟21世纪末全球气候变暖大环境下闽西北中亚热带地区杉木的生长环境。借助生物数码显微图像分析系统测定了土壤增温隔水处理对杉木幼林材管胞形态的影响规律。结果表明,土壤增温5℃极显著降低了杉木幼林材管胞长度、宽度、腔径和长宽比,显著提高了杉木幼林材管胞壁腔比,而对杉木幼林材管胞壁厚影响不显著;隔离降水50%极显著降低了杉木幼林材管胞宽度、壁厚和腔径,极显著提高了杉木幼林材管胞长宽比,而对杉木幼林材管胞长度、壁腔比影响不显著;土壤增温5℃且隔离降水50%极显著降低了杉木幼林材管胞的壁厚,显著降低了杉木幼林材管胞的长宽比;土壤增温对杉木幼林材管胞形态的影响总体上大于隔离降水。研究结果为全球变暖大环境下杉木人工林木材品质定向培育及其合理利用提供理论依据。

The methods of using underground pipeline to increase soil temperature by 5℃and transparent U-shaped pipe to exclude precipitation by 50%were used to simulate the growth environment of Chinese fir(Cunninghamia lanceolata)in the middle subtropical region of Northwestern Fujian Province under the global warming environment at the end of the 21st century.The effects of soil warming and precipitation exclusion on the tracheid morphology of young Chinese fir wood were studied by using the system of biological digital micro image analysis.The results showed that when the soil temperature increased by 5℃,the tracheid length,width,cavity diameter and length-width ratio decreased extremely and significantly,and the tracheid wall-cavity ratio increased significantly,no significant effect was observed on the tracheid wall thickness.When the precipitation was excluded by 50%,the tracheid width,wall thickness and cavity diameter decreased extremely and significantly,while the tracheid length-width ratio increased extremely and significantly,no significant effect on the tracheid length and wall-cacity ratio was found.When both methods were adopted,the thickness of tracheids were extremely and significantly reduced,and the ratio of length to width of tracheids reduced significantly.The impact of soil warming on tracheid morphology of young Chinese fir was overall greater than that of precipitation exclusion.The results provide theoretical basis for the directional cultivation and rational utilization of wood quality of Chinese Fir in the global warming environment.