Newswise — If you’ve noticed that spring seems to be arriving earlier, forcing blooms to burst and leaves to unfurl sooner than expected, scientists may have found one of the reasons. An international research team that includes Steven Travers, assistant professor of biological sciences at North Dakota State University, Fargo, N.D., USA, has shown that experiments underpredict how plants respond to climate change. The research, which included 22 institutions in the U.S., Canada, Sweden, Switzerland and the United Kingdom, is being published in an advance online issue of the journal Nature.
The research team analyzed 50 plant studies on four continents. The notable research results show that the timing of flowering and leafing plants, due to global warming, appears to be much greater than previously estimated in warming experiments.
“The data suggest that the advances in the start of spring worldwide could be much greater than previously estimated,” said Dr. Travers. “We know that plants are shifting the timing of flowering and leafing all over the world in response to climate change, with potentially important ecological effects, but we are basing predictions of how much timing is shifting and what future communities will look like on the outcome of artificial warming experiments over short periods of time,” he said.
“Instead, our study found that plants are shifting more dramatically across the globe than predicted by the artificial experiments. Thus, to better understand the ecological consequences of climate change, we need to establish more long-term observatory networks of plants in the field and improve artificial warming experiments,” said Dr. Travers.
Such findings could have significant implications for predicting global models of future climate change. How plants respond to climate change plays an important role in water supply, crop pollination and ecosystems.
Known as phenology, biologists study the timing of annual plant events, since they provide very visible and consistent responses to climate change. Ecologists use long-term historical records to track the leafing and flowering of plants. But ecologists often have to also use experiments in field plots to estimate how plants respond to temperature.
The research team created new global databases and then compared how sensitive the plants were to temperature, documenting the degree to which plants shift the timing of leafing and flowering with warming. Calculations were made from experiments and then compared to long-term monitoring records.
For more than two decades, scientists have used warming experiments to extrapolate future climate conditions. The approach rests on a critical but little-tested assumption that plant responses to experimental warming match the long-term responses to global warming. The group of researchers tested that assumption to assess how effective warming experiments are for long-term forecasting and prediction.
Researchers found that experiments underpredicted the plants’ responses to temperature by more than fourfold, when compared with long-term historical records. The group compared 1,634 species based on long-term observations and short-term warming experiments, with research results noted in the paper “Warming experiments underpredict plant phenological responses to climate change.”
The results of this research show that using experiments and historical data may be providing a less than full picture of climate change. Improving the design of warming experiments is expected to be crucial, according to researchers involved in the study.
Lead author Elizabeth Wolkovich at the University of British Columbia led the interdisciplinary team of scientists while she was a postdoctoral fellow at the University of California, San Diego, along with assistant professor of biology Elsa Cleland.
The research was conducted as part of the Forecasting Phenology Working Group supported by the National Center for Ecological Analysis and Synthesis (EF-0553768), with additional support from National Science Foundation grants DBI-0905806, IOS-0639794, DEB-0922080 and the National Sciences and Engineering Research Council of Canada CREATE Training Program.
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
Nature is a weekly international journal publishing the finest peer-reviewed research in all fields of science and technology on the basis of its originality, importance, interdisciplinary interest, timeliness, accessibility, elegance and surprising conclusions. Nature is the world’s most highly cited interdisciplinary science journal, according to the 2010 Journal Citation Reports Science Edition (Thomson Reuters, 2011)
North Dakota State University, Fargo, is a student focused, land-grant, research university – an economic engine that educates students, conducts primary research, creates new knowledge and advances technology. NDSU is among the top 108 universities in the country with very high research activity, as determined by the Carnegie Commission on Higher Education. http://www.ndsu.edu/research
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