通过氮肥处理实验及利用红外光谱检测白泥岗珙桐（Davidia involucrata）幼树叶尖氮含量实验，探讨了将红外光谱分析应用于研究森林边缘效应的可行性，并为珙桐保护提供理论依据。结果表明:5个氮素水平处理的珙桐幼苗、叶尖和叶中均表现出明显的氮含量和傅立叶红外转换光谱差异,相关性分析表明叶尖比叶中更能反映珙桐的氮营养状况；光谱指数（A1653-A3400）/（A1653+A3400）随叶中氮含量和供氮水平的提高而提高，说明傅立叶转换红外光谱可用于检测珙桐的氮营养水平，为利用红外光谱分析珙桐氮营养水平边缘效应提供了理论基础。利用傅立叶转换红外光谱法研究白泥岗珙桐林氮素状况的边缘效应表明：在一定距离范围内珙桐氮营养水平由林外向林内逐渐上升，不同方位和不同距离珙桐氮营养水平均存在程度不同的差异，说明方位对珙桐氮素状况的影响显著；珙桐林片段化在生理上对珙桐的影响至少到达30～40m处，而林东至少到达90～100m处，说明林东人为破坏对残存的珙桐生长影响很大。实验结果与其它作者用传统方法对森林边缘氮素分布状况及植物吸收氮素状况的研究结果一致，说明利用红外光谱分析珙桐氮营养水平边缘效应是可行的。实验中还发现采样和样品前处理对结果可靠性有较大影响,样品前处理后必须保持干燥、平整。
The practicability of edge effect research with FTIR (Fourier transform infrared spectroscopy) was investigated by two experiments. In the first, Davidia involucrata seedlings were treated with nitrogen fertilizer and nitrogen content of both tip and middle parts of seedling leaves was detected with FTIR and the method of Kjeldahl. The results showed that there were significant differences in nitrogen content among five treatment levels, either between tips or between middle parts of leaves. The nutritional status could be well estimated by leaf tips in terms of nitrogen content compared with that of middle parts of leaves according to correlation analysis. Spectral index （A1653-A3400）/（A1653+A3400） was revealed to be raised with the increase in availability and of leaf content of nitrogen, which suggested that it is possible to detect the nutritional status of D. involucrata seedlings in terms of nitrogen content by FTIR. In the second, D. involucrata leaves were collected from four aspects in Bainigang, Wolong National Nature Reserve. Tips of the leaves were analyzed with FTIR. The edge effects of nitrogen status of D. involucrata in Bainigang in terms of FTIR showed that the nitrogen levels rose from border to core areas of the forest within certain distance and the average nitrogen levels varied among different aspects and distances to different extents. It suggested that the nitrogen status of D. involucrata was significantly affected by aspect. The D. involucrate fragmentation of forest would impact the regular physiology of internal trees growing at least 30 to 40 meters away from the fragmented border. The impacts were at least 90 to 100 meters from the edge. It suggested that the growth of remaining D. involucrata was impacted seriously by human activities in the east of the forest. The results were consistent with those of previous studies of nitrogen distribution and plant nitrogen absorption at the forest edge. It showed that studying edge-effect of D. involucrata with FTIR is practicable. In our experiments, we discovered that accurate results require that the sample must be kept dry and flat.
全 文 ：