Dec 26, 2017

Global warming leads to more uniform spring phenology across elevations

Yann Vitasse, Constant Signarbieux, Yongshuo H. Fu
Proceedings of the National Academy of Sciences
  • States that a famous American entomologist, Andrew D. Hopkins, estimated in 1920 the progressive delay in tree leaf-out with increasing latitude, longitude, and elevation, a phenomenon referred to as “Hopkins’ bioclimatic law”
  • States that in the early 1960s, the elevation-induced phenological shift (EPS) was approximately 34 days’ delay for every 1,000-meter increase in elevation, conforming to Hopkins’ bioclimatic law
  • Shows, based on massive ground observations in the European Alps, that the shift has reduced by 35% to 22 days' delay for every 1,000-meter increase in elevation
  • Finds that under similar spring temperatures, the EPS was substantially reduced in years when the previous winter was warmer
  • Concludes that winter warming is likely to be responsible for this strong reduction in the EPS and future climate warming may strengthen this trend