Nav: Home

Study tracks decades of life cycle changes in nonwoody plants

June 09, 2020

CHAMPAIGN, Ill. -- For 25 years, Carol Augspurger visited a patch of ancient woods near Urbana, Illinois to look at the same 25 one-square-meter plots of earth she first demarcated for study in 1993. She surveyed the plots once a week in spring and summer, tracking the major life events of each of the herbaceous plants that grew there. In fall, she visited every other week. In winter, once a month.

Over the course of her study, Augspurger made nearly 600,000 observations of 43 plant species in Trelease Woods, a 60.5-acre remnant of old-growth forest in central Illinois. She noted 10 distinct developmental stages in the plants' lives, including when they emerged in spring, how long it took them to mature, when the flowers opened and died, when the leaves began to lose their greenness and when the plants went dormant. Augspurger is a professor emerita of plant biology at the University of Illinois at Urbana-Champaign.

By tracking these events and their relationship to average daily temperature and precipitation records, Augspurger and her colleague, Illinois Natural History Survey statistician and plant ecologist David Zaya, found that some shifts in the timing of plant seasonal life cycle events correlated with temperature trends.

The findings appear in the journal Ecological Monographs.

"We marked every major life cycle event in our plants from emergence until they went dormant," Augspurger said. "And we did it for an intact community, a natural forest community."

The analysis revealed that by the end of the study in 2017, the first spring plants were emerging almost four days later in March than they had in the early 1990s. But their growing seasons were getting shorter: Dormancy was occurring six days earlier. March average temperatures got slightly cooler over the same time period, but April temperatures were rising.

Plants that emerged in late spring - typically after April 1 - were undergoing even more dramatic shifts. Their growing seasons were lengthening: The period from emergence to dormancy lasted more than 40 days longer for these plants at the end of the study than at the beginning.

"For the early species, the growing season was a little bit shorter," Zaya said. "But for the late species, the growing season was 20 days longer per decade."

The duration of leaf expansion and flowering was shorter for the late-spring plants, while senescence, their period of aging, got longer. During senescence, plants gradually decline in making sugar and transfer their energy stores underground, but they do not produce new leaves, flowers or fruit. The increasing duration of senescence corresponded with higher average temperatures in the fall.

"It may be that the late-spring species are benefiting from changing temperature trends by being able to grow and get carbon for a longer period of time in the fall," Zaya said. "This suggests that there may be winners and losers in the plant community as a result of climate change, where some plants can respond more, some can respond less."

Many of the changes seen in the plants paralleled the temperature trends, but the researchers caution that the study does not prove that changing temperatures are driving the seasonal life cycle shifts in plants. Tying any specific trend in plants to climate change is tricky, Augspurger said.

"If you look at these 25 years of Illinois weather, climate change is not happening uniformly every month of the year," she said. "The minimum temperatures are changing more than the maximums, for example, and March is not changing as much as May. It's not only that the different plant species may respond in different ways to the changes, but the weather itself is changing differently."

Regardless of the cause, the shifting patterns among plant species likely influence their interactions with herbivores, pollinators and each other, Augspurger said.

"What they do developmentally ultimately affects their ability to survive, grow and reproduce," she said. "If they're changing their period of activity, they're either going to have a shorter or longer time to gain carbon, to absorb nutrients and to put it together into making flowers, seeds and offspring. This can affect species' abundance and survival, and the health of the overall ecosystem."
The INHS is a division of the Prairie Research Institute at the University of Illinois at Urbana-Champaign.

Editor's notes:

To reach Carol Augspurger, call 217-333-1298; email

To reach David Zaya, email

The paper "Concordance of long-term shifts with climate warming varies among phenological events and herbaceous species" is available online and from the U. of I. News Bureau

University of Illinois at Urbana-Champaign, News Bureau

Related Climate Change Articles:

Mysterious climate change
New research findings underline the crucial role that sea ice throughout the Southern Ocean played for atmospheric CO2 in times of rapid climate change in the past.
Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.
Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.
Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.
Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.
A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.
Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).
Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.
Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.
Could climate change cause infertility?
A number of plant and animal species could find it increasingly difficult to reproduce if climate change worsens and global temperatures become more extreme -- a stark warning highlighted by new scientific research.
More Climate Change News and Climate Change Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at     You can read The Transition Integrity Project's report here.