Figure 4. A descriptive model showing the effects of midseason warming.

The degree to which early and late species show a phenological advancement may depend on the timing of warming and not necessarily the amount of warming. In year 2, relative to year 1, warming “ramps-up” early in the season, allowing both the early taxon (requiring 100 GDDs) and the late taxon (requiring 500 GDDs) to experience a significant phenological advancement. In year 3, however, the advancement occurs later in the season, leading to only the later species experiencing a significant advancement.