By Jessica Robertson, (Science Features) 5/2/12
As the climate has warmed, many plants are starting to grow leaves and bloom flowers earlier. A new study published in the journal, Nature, suggests that most field experiments may underestimate the degree to which the timing of leafing and flowering changes with global warming.
Understanding how plants are responding to climate change will help develop more accurate indicators of spring, forecast the onset of allergy season or the chances of western wildfires, manage wildlife and invasive plants, and help inform habitat restoration plans.
In this new study, scientists evaluated the sensitivity of plants to changes in temperature using two sources: experimental plots versus historical observations from natural sites.
The experiments analyzed in this study were conducted by artificially inducing warming in small study plots, and then measuring plant responses. The historical observations entailed long-term monitoring of multiple species at natural ecological research sites without any manipulation. The date of leafing and flowering was synthesized for dozens of warming experiments and monitoring sites across the Northern Hemisphere.
Scientists conclude that compared to warming experiments, historical monitoring shows temperature sensitivity to be four times greater for leafing and over eight times faster for flowering.