Growing seasons are getting longer, a phenomenon partially explained by increasing global temperatures. Recent reports suggest that a strong correlation exists between warming and advances in spring phenology but that a weaker correlation is evident between warming and autumnal events implying that other factors may be influencing the timing of autumnal phenology. Using freely rooted, field-grown Populus in two Free Air CO2 Enrichment Experiments (AspenFACE and PopFACE), we present evidence from two continents and over 2 years that increasing atmospheric CO2 acts directly to delay autumnal leaf coloration and leaf fall.
Taylor, Gail; Tallis, Matthew J.; Giardina, Christian P.; Percy, Kevin E.; Miglietta, Franco; Gupta, Pooja S.; Gioli, Beniamin; Calfapietra, Carlo; Gielen, Birgit; Kubiske, Mark E.; Scarascia-Mugnozza, Giuseppe E.; Kets, Katre; Long, Stephen P.; Karnosky, David F. 2008. Future atmospheric CO2 leads to delayed autumnal senescence. Global Change Biology. 14: 264-275.