濒危连香树种群性比和雌雄株功能性状的差异

雌雄异株植物种群性比偏倚和性别间功能性状的差异可能对种群维持产生不利影响,目前的研究很少关注雌雄异株濒危植物的性别差异.本文调查了四川小寨子沟国家级自然保护区内天然连香树种群性比并比较其雌雄株之间的形态、光合能力、水分和养分利用效率差异.结果发现,连香树种群性比显著偏雌(F/M=1.97;x^2 =4.46,P=0.035),雌株的胸径、冠幅、最大光合速率、表观量子效率、最大羧化效率、比叶面积、叶氮含量及水分、氮和磷利用效率分别比雄株高44.50%、27.94%、20.11%、50%、21.14%、14.32%、14.86%、158.7%、19.74%和28.03%,而其气孔导度、胞间CO2浓度、蒸腾速率和光补偿点分别低20.83%、24.61%、56.11%和44.44%,表明该地连香树种群存在性别偏倚且性别间已呈现出性别二态性,这可能是其濒危的重要原因,建议在探讨其濒危机制中应该考虑性别的因素.

Sex ratio and sexual difference of functional traits in the endangered plant Cercidiphyllum japonicum

MA Wen-bao;LIAO Cheng-yun;JI Hui-juan;CHEN Xue;DONG Ting-fa(Ecological Restoration and Conservation of Forests and Wetlands Key Laboratory of Sichuan Province, Sichuan Academy of Forestry, Chengdu 610081, China;Sichuan Forestry Inventory and Planting Institute, Chengdu 610081, China;Sichuan Jiangyou Middle School, Jiangyou 621700, Sichuan, China;Key Laboratory of Southwest China Wildlife Resources Conservation, Ministry of Education, College of Life Sciences, China West Normal University, Nanchong 637009, Sichuan, China)