Biogeosciences, 13, 3847–3861, 2016 www.biogeosciences.net/13/3847/2016/ doi:10.5194/bg-13-3847-2016 © Author(s) 2016. CC Attribution 3.0 License. Spaceborne potential for examining taiga–tundra ecotone form and vulnerability Paul M. Montesano1,2, Guoqing Sun2,3, Ralph O. Dubayah3, and K. Jon Ranson2 1Science Systems and Applications, Inc., Lanham, MD 20706, USA 2Biospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA 3University of Maryland, Department of Geographical Sciences, College Park, MD 20742, USA Correspondence to: Paul M. Montesano (
[email protected]) Received: 9 November 2015 – Published in Biogeosciences Discuss.: 15 January 2016 Revised: 31 May 2016 – Accepted: 9 June 2016 – Published: 6 July 2016 Abstract. In the taiga–tundra ecotone (TTE), site-dependent tainty of height estimates in forest patches may improve de- forest structure characteristics can influence the subtle and piction of TTE form, which may help explain variable forest heterogeneous structural changes that occur across the broad responses in the TTE to climate change and the vulnerability circumpolar extent. Such changes may be related to ecotone of portions of the TTE to forest structure change. form, described by the horizontal and vertical patterns of for- est structure (e.g., tree cover, density, and height) within TTE forest patches, driven by local site conditions, and linked to ecotone dynamics. The unique circumstance of subtle, vari- 1 Introduction able, and widespread vegetation change warrants the appli- cation of spaceborne data including high-resolution (< 5 m) 1.1 TTE vegetation structure and processes spaceborne imagery (HRSI) across broad scales for examin- ing TTE form and predicting dynamics.