Rees Gareth, Brown Ian, Mikkola Kari, Virtanen Tarmo, Werkman Ben
Scott Polar Research Institute, University of Cambridge, Lensfield Road, Cambridge CB2 1ER, United Kingdom.
Ambio. 2002 Aug;Spec No 12:56-62.
This paper discusses some of the difficulties in establishing the location of the Arctic treeline and forest line on a circumpolar basis, and the contribution that remote sensing, particularly from spaceborne platforms, can make in resolving them. Spaceborne techniques can provide spatial resolutions as fine as a few meters, although the requirements for regional or global coverage are likely to limit the resolution to 30 to 100 m. Since this will preclude the identification of individual trees, the definition of the treeline will be based on statistical parameters estimated from satellite images. The optimum criteria for these parameters remain to be determined. Most remote-sensing observations that are suited to the measurement of the distribution of vegetation, and identification of its type, are based on the visible and near-infrared (VIR) parts of the electromagnetic spectrum, although there is increasing interest in the use of active microwave (radar) techniques. We discuss the basis of both types of approach and the techniques that follow from them, and present 3 case studies from the Russian Arctic.
本文讨论了在环北极基础上确定北极树木线和森林线位置时遇到的一些困难，以及遥感技术，特别是星载平台遥感技术在解决这些问题方面所能做出的贡献。星载技术可以提供低至几米的空间分辨率，不过对区域或全球覆盖范围的要求可能会将分辨率限制在30至100米。由于这将无法识别单棵树木，树木线的定义将基于从卫星图像估算出的统计参数。这些参数的最佳标准仍有待确定。大多数适用于测量植被分布及其类型识别的遥感观测都是基于电磁光谱的可见光和近红外（VIR）部分，尽管人们对使用有源微波（雷达）技术的兴趣与日俱增。我们讨论了这两种方法的基础以及由此衍生出的技术，并展示了来自俄罗斯北极地区的3个案例研究。
