Five years of land surface phenology in a large-scale flooding and draining manipulation in a coastal Arctic ecosystem

Abstract

This study was motivated by the knowledge gap for observing the complex interplay between surface hydrology and plant phenology in arctic landscapes and was conducted as part of a large scale, multi investigator flooding and draining experiment near Barrow, Alaska (71{degrees}1701\" N, 156{degrees}3548\" W) during 2005 - 2009. Hyperspectral reflectance data were collected in the visible to near IR region of the spectrum using a robotic tram system that operated along a 300m transects during the snow free growing period between June and August, 2005-09. Interannual patterns of land-surface phenology (NDVI) unexpectedly lacked marked differences under experimental conditions. Measurement of NDVI was, however, compromised for presence of surface water. Land-surface phenology and surface water was negatively correlated, which held when scaled to a 2km by 2km MODIS subset of the study area. This result suggested that published findings of greening of the Arctic may relate to a drying of the Arctic i.e. reduced surface water in vegetated high-latitude landscapes where surface water is close to ground level.