Journal Article Arctic Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. climate change ITEX Ice Letter Soil Toolik Lake bryophytes carbon cycle climate constraint cumulative impacts diversity earth system model eddy covariance geoecological mapping gross primary productivity ice-rich permafrost ice-wedge polygons infrastructure law of minimum lichens photo-interpretation photosynthetic seasonality remote sensing thermokarst tundra vegetation change