两种生境常绿和落叶树种叶片氮素分配及与光合能力的关系  

Leaf nitrogen allocation of evergreen and deciduous broad-leaved tree species and their relationships with photosynthetic capacity in the two habitats

作　　者：刘微[1] 李德志[1,2,3] 纪倩倩[1] 陈惠娟[1] 赖苏雯[1] 耿松[1] 贠小涛 陈青青[1] 

机构地区：[1]华东师范大学生态与环境科学学院,上海200241 [2]华东师范大学上海市城市化生态过程与生态恢复重点实验室,上海200241 [3]浙江天童森林生态系统国家野外科学观测研究站,浙江宁波315114

出　　处：《生态科学》2015年第1期1-8,共8页Ecological Science

基　　金：国家自然科学基金资助项目(31170387和31370435)

摘　　要：以天童国家森林公园太白山顶旷地生境和木荷林林下生境18种主要常绿与落叶树种为对象,研究了单位面积叶干重(LMA)、单位叶干重氮含量(N_(mass))、叶细胞壁氮素分配比率(N_(cw)/N_m)和单位叶干重最大净光合速率(A_(mass))在2个生境中的差异及各指标间的关系。结果表明:1)旷地生境各树种间的LMA显著高于林下生境,A_(mass)则显著低于林下生境,N_(mass)、Ncw)/Nm在两种生境中差异不显著;落叶树种具有较小的LMA、较小的Ncw/Nm及较高的A_(mass),未受到光抑制;常绿种具有较大的LMA和Ncw/Nm,在旷地受到显著光抑制。2)2种生境中LMA与N_(mass)、A_(mass)呈显著负相关,与Ncw/Nm呈显著正相关,N_m与A_(mass)呈显著正相关。3)从林下生境到旷地生境,常绿树种表现为维持生长、延长叶寿命为主的适应策略,而落叶树种表现为以提高资源利用效率为主的适应策略。Four leaf functional trait indexes [leaf dry mass per area（LMA）, leaf nitrogen concentration per unit mass（N（mass））, leaf nitrogen allocation proportion in cell wall（N（cw）/Nm） and mass-based maximum photosynthetic rate（A（mass））] were measured in 18 evergreen and an deciduous broad-leaved tree species from Taibai mountain-peak open habitat and from Schima superba forest understory habitat in Tiantong National Forest Park. The results showed that Amass of the trees was lower but LMA was higher in the open habitats than those in the understory habitats. Nmass and N（cw）/Nm of the trees were not significantly different between the two habitats; deciduous tree species possessed smaller LMA, N（cw）/Nm and higher Amassthan evergreen species, and the photoinhibition happened severely in open habitat for the evergreen tree species. More nitrogen was used to protect the photosynthetic system and defense system. LMA was negatively correlated with Nmass and Amass, while it was positively correlated with N（cw）/Nm; Amass and Nmass were positively correlated in both habitats. Our results indicated in the understory habitat, the evergreen tree species showed adaptive strategies characterized by persistence and maintaining survival, extending leaf lifespan and increasing N investments in cell walls, but in the open and dry habitat the deciduous tree species showed adaptive strategies characterized by high nitrogen-use efficiency.

关 键 词：常绿树种 落叶树种 氮素分配 光合能力 适应策略 

分 类 号：S723.132.1[农业科学—林木遗传育种]