Spatial Variablitity of Canopy Structure and Function in the Moist Acidic Tundra

Abstract

Understanding canopy architecture and function is important to link the effects of climate change on carbon, water, and energy exchanges between subarctic vegetation and the atmosphere. Interpreting vegetation spatial variability with satellite products alone is a challenge, due to the patchiness of vegetation in the Arctic ecosystems with transient cloud cover during the summer season that obstructs retrieval of land surface images. To compare and correlate spatial variation of vegetation with satellite data, we collected leaf area index (LAI) and hyperspectral reflectance data in Council, Alaska. To better understand canopy structure and functional variables, we further examined subarctic leaf traits by measuring C:N ratio, leaf mass area (LMA), chlorophyll content, and hyperspectral leaf optical properties. We obtained WorldView-2 Satellite data, which has 8 multispectral bands with 2 m resolution, centered on our study site. There is remarkable variation in spectral reflectance and LAI across three 100-m transects. We discuss how to upscale the information from in-situ observed canopy properties into a landscape scale in tandem with the high-resolution satellite image.