title: Photosynthesis, nitrogen allocation and specific leaf area in invasive Eupatorium adenophorum and native Eupatorium japonicum grown at different irradiances.
abstract: The mechanisms underlying biological invasions are still not well elucidated. In this study, ecophysiological traits of invasive Eupatorium adenophorum and native E. japonicum were compared at 10 irradiances in field. I hypothesized that the invader may allocate a higher fraction of leaf nitrogen (N) to photosynthesis and have higher light-saturated photosynthetic rate (P(max)) and specific leaf area (SLA) than E. japonicum. The invader had a significantly higher ability to acclimate to high irradiance than E. japonicum, while it showed a similar shade-tolerant ability. The invader indeed allocated a higher fraction of leaf N to photosynthesis than E. japonicum, which, with its high leaf N content (N(A)), resulted in a higher N content in photosynthesis (N(P)), contributing to its higher biochemical capacity for photosynthesis and P(max). However, the invader had a significantly lower SLA than E. japonicum, contributing to its higher P(max) but increasing its area-based leaf construction cost. The abilities to acclimate to a wider range of irradiance and to allocate a higher fraction of leaf N to photosynthesis, and the higher P(max), N(A), N(P) and leaf area ratio may contribute to the invasion of the invader. High SLA is not always necessary for invasive species.
authors.affiliation: Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, 88 Xuefu Road, Kunming, Yunnan Province 650223, China. fyl@xtbg.ac.cn
authors.forename: Yu-Long
authors.initials: YL
authors.lastname: Feng
mesh_terms: D004579:Electron Transport / Q000528:radiation effects; D036602:Eupatorium / Q000254:growth & development* / Q000528:radiation effects*; D008027:Light; D009584:Nitrogen / Q000378:metabolism*; D010788:Photosynthesis / Q000528:radiation effects*; D018515:Plant Leaves / Q000378:metabolism* / Q000528:radiation effects*; D054046:Plant Stomata / Q000528:radiation effects
chemical_list: D009584:Nitrogen