摘要
构建异质和同质两种养分环境,选择3个杉木(Cunninghamia lanceolata)优良家系作试验材料,并以马尾松(Pinus massoniana)为参照,通过量化分析不同养分环境中植株生长量、干物质积累和分配、根系形态、养分吸收和利用效率等,研究杉木家系对异质养分环境的适应性反应差异。结果表明,3个杉木参试家系对不同养分环境的生长反应差异显著,‘锦屏45’家系在异质养分环境中苗高生长量大、干物质积累量多、根系发达,而‘龙15’和‘靖398’两个家系则在同质养分环境中表现较好。杉木不同家系的根系均主要在异质养分环境之贫养斑块中大量增生,根系形态可塑性与觅养精确性较低。作为参照的马尾松,对异质养分环境反应敏感,根系广布性大、觅养精确性高。在3个参试杉木家系中,‘龙15’和‘靖398’对异质养分环境的生长反应敏感度低,根系生理可塑性一般,而‘锦屏45’对异质养分环境的生长反应敏感度较高,根系生理可塑性较高。试验观测到不同杉木家系在异质养分环境中根系N、P、K吸收效率通常低于同质养分环境。在富养斑块中的根系养分吸收效率明显低于贫养斑块,这与马尾松在富养斑块中根系养分吸收效率较高有很大的差异。然而杉木家系在富养斑块中根系的养分含量却不同程度地高于贫养斑块或与之相近。‘锦屏45’家系在异质环境中生长表现显著地优于同质养分环境,除因其具有较高的根系生理可塑性外,还与较多比例的干物质和营养元素分配至地上部分、根冠比较小有关。
Aims Chinese fir （ Cunninghamia lanceolata）, an important tree of timber plantations in South China, is a fast-growing coniferous species with high yield and quality of wood. Since the forest soil in South China is highly heterogeneous in nutrients, our objective is to study responses of Chinese fir to soil heterogeneity.
Methods We used pot experiments under heterogeous and homogeneous environments to study tree growth, dry matter accumulation and allocation, root morphology and nutrient absorption efficiency of three open-pollinated varieties of C. lanceolata （‘Long 15＇, ‘Jinping 45＇ and ‘Jing 398＇ ） to detect the differences in their adaptability to the heterogenous nutrient environment.
Important findings The three varieties were significantly different in their adaptability to the heterogenous nutrient environment and in their response to soil patches. ‘Jinpin 45＇ exhibited higher plant height, higher biomass accumulation and more developed roots in the heterogeneous environment than homogeneous environment, but ‘Long 15＇ and ‘Jing 398＇ grew better in the homogeneous environment. Although the responses of the three varieties were different, roots proliferated mainly in poor patches. ‘Jinping 45＇ showed high root physiological plasticity in the heterogeneous environment, but ‘Long 15＇ and ‘Jing 398＇ were low and average, respectively, in the hererogeous environment. The root concentration of N, P and K in the heterogeous environment （poor-patch） was lower than in the homogeneous environment （rich-patch） ; this is different from Pinus massoniana, which had high nutrient absorption. However, concentration of nutrients was not lower in rich-patch than poor-patch. Further more, it can be inferred that ‘Jinping 45＇ grew better in the heterogeneous environment than the homogeneous environment not only because of physiological plasticity but also because of a larger portion of biomass and nutrients distributed to leaves.
出处
《植物生态学报》
CAS
CSCD
北大核心
2008年第1期189-196,共8页
Chinese Journal of Plant Ecology
基金
国家自然科学基金项目(30571482)
关键词
杉木
家系
异质养分环境
适应性
Cunninghamia lanceolata, varieties, heterogeneous nutrient environment, adaptability
