摘要
生境异质性是影响植物生长发育的重要因素。植物木质部水力系统是土壤-植物-大气连续体的主要通路,直接影响植物的基本行为和功能,同时也反映了植物对环境变化的适应性。为对比天目山3种裸子植物枝条木质部水力功能、机械和解剖结构性状在不同生境(自然生境与人工生境)的差异,揭示裸子植物对不同生境的适应机制,该研究以金钱松(Pseudolarix amabilis)、杉木(Cunninghamia lanceolata)和雪松(Cedrus deodara)为研究对象,测定枝木质部导水率、栓塞抗性(导水率损失50%时的水势)、机械以及解剖结构性状。结果发现:1)人工生境植株比自然生境植株水力效率弱,但栓塞抗性强。2)自然生境雪松木质部导水系统存在效率-安全权衡;不论自然还是人工生境杉木、金钱松木质部导水系统均无效率-安全权衡。3)人工生境雪松和金钱松木质部存在机械-安全权衡。相比人工生境,土壤水分有效性低的自然生境中,植物采用增大纹孔膜直径来提高水力效率,此外,还可通过增加木材密度、扩大管胞直径来避免栓塞带来的威胁。
Aims Habitat difference is one of the important factors affecting plant growth and development.Plant xylem hydraulic system is the main pathway of soil-plant-atmosphere continuum,which directly affects the basic behavior and function of plants and reflects the adaptability of plants to environmental changes.In the current study,the differences of xylem hydraulic function,mechanical and anatomical structure traits of three gymnosperm species in Tianmu Mountain,Zhejiang Province in different habitats(field habitat and garden habitat) were compared to reveal the adaptive mechanism of gymnosperm to different habitats.Methods We measured and compared hydraulic safety trait(water potential at 50% loss of conductivity),hydraulic efficiency(specific hydraulic conductivity) and xylem anatomy,between field and garden plants of Pseudolarix amabilis,Cunninghamia lanceolata and Cedrus deodara.Important findings 1) For all tree species,their hydraulic efficiency in garden habitats are lower than that of field habitats,but the embolism resistances are stronger,owing to the complexity of species adaptation strategies.2) No matter in field or garden habitats,there was efficiency-safety trade-off in the xylem water diversion system in Cedrus deodara,but there is no efficiency-safety trade-off in hydraulic system of P.amabilis and Cunninghamia lanceolata.3) There is a trade-off between hydraulic efficiency and mechanical strength in the xylem of P.amabilis and Cedrus deodara in garden habitat.Compared with garden habitats,in field habitats with low soil moisture availability,plants increased pit membrane diameter to improve hydraulic efficiency.In addition,in field habitat,the threat of embolism to plants could be avoided by increased wood density and expanding tracheid diameter.
作者
韩旭丽
赵明水
王忠媛
叶琳峰
陆世通
陈森
李彦
谢江波
HAN Xu-Li;ZHAO Ming-Shui;WANG Zhong-Yuan;YE Lin-Feng;LU Shi-Tong;CHEN Sen;LI Yan;XIE Jiang-Bo(State Key Laboratory of Subtropical Silviculture,College of Forestry and Biotechnology,Zhejiang A&F University,Hangzhou 311300,China;Management Bureau of Tianmu Mountain National Nature Reserve,Hangzhou 311300,China;and 3State Key Laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Ürümqi 830011,China)
出处
《植物生态学报》
CAS
CSCD
北大核心
2022年第4期440-450,共11页
Chinese Journal of Plant Ecology
基金
国家自然科学基金(31901280、31770651和41730638)。
关键词
栓塞抗性
水力效率
机械强度
木质部解剖
效率-安全权衡
cavitation resistance
hydraulic efficiency
mechanical strength
xylem anatomy
efficiency-safety trade-off
