Impact of Multiple Ecological Stressors on a Sub-Arctic Ecosystem: No Interaction Between Extreme Winter Warming Events, Nitrogen Addition and Grazing.

ABSTRACT: Climate change is one of many ongoing human-induced environmental changes, but few studies consider interactive effects between multiple anthropogenic disturbances. In coastal sub-arctic heathland, we quantified the impact of a factorial design simulating extreme winter warming (WW) events (7 days at 6-7°C) combined with episodic summer nitrogen (+N) depositions (5 kg N ha-1) on plant winter physiology, plant community composition and ecosystem CO2 fluxes of an Empetrum nigrum dominated heathland during 3 consecutive years in northern Norway. We expected that the +N would exacerbate any stress effects caused by the WW treatment. During WW events, ecosystem respiration doubled, leaf respiration declined (-58%), efficiency of Photosystem II (Fv/Fm) increased (between 26 and 88%), while cell

SUBMITTER: Bokhorst S 

PROVIDER: S-EPMC6284199 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature