Scientific experiments to measure the rate and effects of climate change on plants aren't matching up to what is happening in nature, a new study finds.

In fact, observations on the environment show that changes in nature is happening much faster than in the scientist's lab.

Researchers with Columbia University's Lamont-Doherty Earth Observatory, the NASA Goddard Institute for Space Studies and the University of California, San Diego, found that experiments may underestimate the true timing of flowering and leaf-making by between four and eight times.

"We were surprised at how big the difference actually was," said co-author and climate modeler Benjamin Cook, who works at Lamont Doherty and the Goddard Institute.

Phenology, the study of timing in the life of plants and animals, has been disrupted by climate change. An example is Washington, D.C.'s cherry blossoms, which now bloom about a week earlier than in the 1970s.

"This suggests that predicted ecosystem changes -- including continuing advances in the start of spring across much of the globe -- may be far greater than current estimates based on data from experiments," said Elizabeth Wolkovich, a postdoctoral fellow at the University of California, San Diego, who led the study.

The study, released in Nature, included 1,643 species on four continents. For every 1-degree-Celsius rise in temperature in an experiment, the rate of flowering and leafing would advance from 1 to 1.6 days. In nature, advances were four times faster for leafing and more than eight times faster for flowering.

Reasons for the differences in results could include genetic adaptations in plants to develop more quickly. It could also be tied to the methods researchers use to artificially warm a lab environment to mimic climate change.

The biggest relevance, Cook said, is for those working in species conservation.

"When you want to plan for climate change, what you want to know is which species will be sensitive to climate change and which won't," he said.

The researchers relied on observational data sets from citizen scientists, people without the qualifications to be a scientist who have chosen to observe and record patterns in nature. Observational sets range in duration from five to six years up to nearly 80 years.

In January, the Agriculture Department released a new plant hardiness map, the first major update since 1990. Growing zones in the United States have shifted northward, meaning many plants are now able to tolerate the climate in zones farther north than before (ClimateWire, Jan. 26).

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC., 202-628-6500