基于鱼眼镜头的林冠郁闭度简易测量方法

为探究一种精度高、操作简便，成本低、便携性高的郁闭度观测方法和设备，于2008年8月在水土保持与荒漠化防治教育部重点实验室方山试验站土桥沟流域进行了对比观测试验，提出了采用鱼眼镜头获取林分冠层图像，应用Photoshop软件测定林分郁闭度的新方法（CCPS法），并以冠层分析仪所测28个固定样地的郁闭度值为基准值，对CCPS法所获冠层图像客观性和方法的系统偏差、精度和稳定性进行检验与测试，探讨了不同测量高度、林冠选择方式和林木主干对郁闭度测量结果的影响。结果表明:建立多边形林冠测量范围，其测量精度可达99.43%；在距地面90～130 cm高度范围内测量结果最为稳定，且便于操作；林木主干使郁闭度测量值均偏大，尤其对针叶林影响较大；该方法的稳定系数可达92.86%。 

Simplified approach to measure canopy closure based on fish lenses

This study provides a new approach to measure the canopy closure (CCPS),which is simple,with high accuracy,low cost,easy to handle and portable. In August of 2008,the comparison study was done in Tuqiaogou watershed of Fangshan Field Station of Key Laboratory of Soil and Water Conservation & Desertification Combating. We used canopy digital images from fish-eye lenses and analyzed them using Photoshop software. Twenty eight sample sites were selected to test their canopy closure. Based on the data from cano...