Light Reflectance, Transmittance, and Utilization Efficiency of Leaves of Mikania micrantha and Interspecies Comparison within the Same Community
薇甘菊叶片对光反射、透射和利用效率及其与同群落植物之比较研究

We measured the light transmittance, reflectance and photosynthetic capacity of leaves of Mikania micrantha and 19 other species of plants (herbal and woody sp.) in the same community. M. micrantha and other plants were similar in transmittance and reflectance spectra and showed no apparent differences in the relation between leaf-optical and photosynthetic-related in the same community. On average, the leaf reflectance and leaf transmittance were higher for this weed than for herbs and then woody species, and the optical vegetation parameters of SR680, SR750 and PRI were lower for M. micrantha than for other herbs and woody species. However, the photosynthetic capacity of M. micrantha (light use efficiency , photosynthetic water-use efficiency, electron transportation rate and net photosynthetic rate) was close to or somewhat higher than that of other species. Moreover, leaves of M. micrantha reflected or transmitted much more light in summer than in winter, which favors the release of redundant light in summer and absorption of more light in winter. These strategies for light utilization by M. micrantha adapt to the strong light environment above the vegetation surface (where M. micrantha is generally grown) , and may favor the rapid invasion of this weed in new habitats.