不同海拔的长白山岳桦叶片反射光谱研究

通过对长白山不同海拔下岳桦叶片反射光谱的研究,探讨岳桦叶片对高山环境的适应机制.结果表明:不同海拔间岳桦叶片光谱反射率及光谱指数有较大差异.在1750～2000m海拔梯度内,叶绿素归一化指数(chlNDI)显示;岳桦叶片叶绿素相对含量先升高再降低;光化学反射指数(PRI)显示岳桦叶片光合有效辐射利用效率在2000m处最...

Spectral reflectance of Betula ermanii at different altitudes in the Changbai mountains

The leaf spectral reflectance of the Betula ermanii along an altitudinal gradient in the Changbai mountains was measured in an attempt to reveal underlying physiological mechanisms of environmental adaptation of Betula ermanii. The results showed significant differences in the spectral reflectance at different elevations, and the spectral indices also varied significantly. From 1 750 m to 2 000 m, the chlorophyll normalized difference index (chlNDI) indicated that chlorophyll concentrations increased at first and then decreased. Photochemical reflectance index (PRI) indicated lower PAR use efficiency at 2 000 m than lower elevations. Carotenoid index (CAI) indicated that the carotenoid concentrations at 1 750, 1 900 and 2 000 m had no significant difference. In addition, both chlorophyll concentrations and PAR use efficiency in the timberline were higher than those at 2 000 m, while the carotenoid concentration was lower than that at 2 000 m. Hence, we conclud that physiological conditions and stress are different at different elevations, and near 1 900 m is the best region for the growth of B. ermanii; the surroundings above the timberline is unsuitable for the growth and development, thus, higher elevation limits its distribution.