遥感用于森林生物多样性监测的进展

随着物种和栖息地的丧失,全球范围的生物多样性保护已经成为迫切的需要。航空航天技术的迅猛发展使遥感成为能提供跨越不同时空尺度监测陆地生态系统生物多样性的重要工具,这方面的研究在欧美等国已经有了小范围的开展,在国内刚刚起步。国外关于生物多样性遥感探测的方法基本有3种:1.利用遥感数据直接对物种或生境制图,进而估算生物多样性;2 .建立遥感数据的光谱反射率与地面观测物种多样性的关系模型;3.与野外调查数据结合直接在遥感数据上进行生物多样性指数制图。研究表明,物种直接制图法只能应用于较小的范围;生境制图的方法,应用广泛,技术相对成熟,研究范围局限于几百公里的范畴,但不能获取生境内部的多样性信息。光谱模型技术目前正处于探索阶段,对于植被复杂、生物多样性高的地域,具有较大的应用潜力。在遥感数据上直接进行生物多样性制图在加拿大已经得到了应用。

Progress on measuring forest biodiversity with remote sensing technique

As the rates of habitat and species destruction continue to rise, the need for conserving biodiversity has become increasingly imperative worldwide during the last decade. With development of the space technology, remote sensing has been a useful tool for monitoring the land surface at different temporal and spatial scales. This paper reviews the application of remote sensing in assessing the forest biodiversity. The existing studies of species biodiversity using remote sensing could be categorized into three types: the first was direct mapping of individual plants or habitat with the remote sensing data, and predictions of species biodiversity based on these maps; the second technique involves establishing of direct relationships between spectral radiance values recorded by remotely sensed data and species biodiversity from field observations; and thirdly, using the classification technique to gain the biodiversity indices from remote sensing data based on the a priori model built upon the field observations, geographic factors and remote sensing. The first method was widely used and more suitable for biodiversity monitoring. Mapping habitat with remote sensing could be used at larger spatial scales, but mapping individual species has been restricted to the much smaller scales with the high-resolution remote sensing images. The relationship model may be useful for the higher levels of species diversity, and can be applied at the national scale. The improved method has been tested in Canada, with favorable outcomes.