Estimating morphological parameters of Tamarix ramosissima by Digital hemispherical image in the lower reaches of heihe river, northwest China

Tamarix ramosissima is a dominant shrub and mainly contributes to total biomass in the lower reaches of Heihe River. In order to study the biomass and growth status of the shrub, we need to measure the morphological parameters. Usually, the morphological parameters are measured by field survey. However, the method is low in efficient and accurate. In this study, the hemispherical photography was used to obtain the morphological parameters of Tamarix ramosissima. The hemispherical images of Tamarix ramosissima were obtained from the top of canopy by digital camera with fisheye lens, then processed and overlaid with the calibration parameter layer to estimate the morphological parameters. The results show that the hemispherical photography had high accuracy in estimating the morphological parameters. The method is a convenient and feasible approach, and can provide a scientific data for the biomass models.