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TITLE | Gas exchange characteristics of the invasive species Mikania micrantha and its indigenous congener M. cordata (Asteraceae) in South China |
AUTHOR | Xiong DENG South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650, P.R. China Wan-Hui YE South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650, P.R. China Hui-Ling FENG South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650, P.R. China Qi-He YANG South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650, P.R. China Hong-Ling CAO South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650, P.R. China Kai-yang XU South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650, P.R. China Yun ZHANG South China Botanic Garden, Chinese Academy of Sciences, Guangzhou 510650, P.R. China |
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ABSTRACT | In South China, the photosynthetic characteristics of an invasive exotic weed Mikania micrantha H.B. Kunth and its indigenous close congener Mikania cordata (Burm. f.) B.L. Robinson were studied. Mikania micrantha exhibited a greater biochemical capacity for photosynthesis than M. cordata, as the former had higher Vcmax and Jmax, which lead to its higher maximum assimilation rate (Amax) values. Similar light compensation point, apparent quantum yield (a), and dark respiration (Rd), suggested a similar shade-tolerance. Higher Amax, light saturating point, and CO2 saturating point give M. micrantha greater potential to acclimate to brighter environments and a larger pool of available carbon. These differences in photosynthetic characteristics could be a basis for their niche partitioning. The leaf traits of the native and invasive Mikania species were as follows: higher construction cost (CC), lower specific leaf area (SLA), as well as lower mass-based leaf N and photosynthetic nitrogen-use efficiency (PNUE) for the native species, but M. micrantha had lower area-based leaf N. The higher water use efficiency (WUE) and d13C observed in M. micrantha was probably due to its high photosynthetic capacity and not to reduced stomatal conductance, explaining the absence of any trade-off between WUE and PNUE. |
KEYWORD | Invasive species, Mikania; Nitrogen use efficiency; Photosynthetic characteristics; Specific leaf area; |
ARTICLE INFO | Botanical Bulletin of Academia Sinica, Volume 45 Number 3 July 2004, page 213-220, 8 pages |
PUBLISHER | Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, Republic of China |