基于RS与GIS的乔木层物种多样性分布格局——以辽东山区水源涵养林为例

Distribution pattern of tree layer species diversity based on RS and GIS:A case study of water conservation forests in montane regions of eastern Liaoning Province of China

根据ETM^＋遥感影像与实地考察数据，通过建立乔木层物种多样性反演模型及模型地面验证等方法，对辽东山区水源涵养林乔木层物种多样性分布格局及其在不同海拔高度和坡向上的分布状况进行了研究。结果表明：归一化植被指数（NDVI）、湿度（TC3）和绿度（TC2）与Shannon—Wiener多样性指数相关性较高，3个植被指数-9Shannon．Wiener多样性指数的回归模型可靠（R^2=0．637，P〈0．01）。地面验证结果表明，模型能解释乔木层物种多样性的69．38％；乔木层物种多样性指数主要集中在1．0-2．2，并符合“中间海拔高度膨胀”理论；坡向对乔木层物种多样性分布的影响体现在东北坡出现高物种多样性的可能性最大，验证了由于坡向导致的水热差异，从而影响物种多样性的结论。

Based on the ETM ^＋ remote sensing images and field investigation data, an inversion model for the tree layer species diversity was established and verified, and used to study the distribution pattern of tree layer species diversity of water conservation forests at different altitudes and aspects in the montane region of eastern Liaoning Province. In the study area, there was a high correlation between the Shannon-Wiener diversity index and the normalized difference vegetation index （NDVI）, humidity （TC3 ）, and green vegetation index （TC2）. The regression mod- el of Shannon-Wiener diversity index and the three vegetation indices was reliable （R^2 = 0. 637, P 〈0. 01 ）. Field verification indicated that this inversion model could explain 69.38% of the tree layer species diversity. The tree layer species diversity was mainly within the range of 1.0- 2.2, and presented ＂a high swelling at mid altitude＂. The effects of aspect on the distribution of tree layer species diversity mainly exhibited in the greatest probability of high species diversity occurred on northeast slope, which verified the viewpoint that aspect induced the differences in water and heat conditions, and thus, affected species diversity.