Temperature increases causing tropical forests to blossom

Jul 08, 2013
New research shows that temperature influences tropical flowering
Temperature and/or precipitation are better predictors of tropical flowering than cloudiness. Credit: STRI Archives

A new study led by Florida State University researcher Stephanie Pau shows that tropical forests are producing more flowers in response to only slight increases in temperature.

The study examined how changes in temperature, clouds and rainfall affect the number of flowers that produce. Results showed that clouds mainly have an effect over short-term seasonal growth, but longer-term changes of these forests appear to be due to temperature. While other studies have used long-term data, this is the first study to combine these data with direct estimates of cloud cover based on .

The results of the study, "Clouds and Temperature Drive Dynamic Changes in Tropical Flower Production," was published July 7 in the journal Nature Climate Change.

"Tropical forests are commonly thought of as the lungs of the earth and how many flowers they produce is one vital sign of their health," said Pau, an assistant professor in Florida State's Department of Geography. "However, there is a point at which forests can get too warm and flower production will decrease. We're not seeing that yet at the sites we looked at, and whether that happens depends on how much the tropics will continue to warm."

U.S. Geological Survey Senior Scientist Julio Betancourt, who was not involved in the study, described Pau's research as "clever."

"It integrates ground and over nearly three decades to tease apart the influence of temperature and cloudiness on local flower production," Betancourt said. "It confirms other recent findings that, in the tropics, even a modest warming can pack quite a punch."

Pau led a team of international researchers who studied seasonal and year-to-year flower production in two contrasting tropical forests—a seasonally dry forest on Barro Colorado Island, Panama, and an "ever-wet" forest in Luquillo, Puerto Rico.

The seasonally dry site, according to Pau, has been producing more flowers at an average rate of 3 percent each year over the last several decades, an increase that appears to be tied to warming temperatures.

"We studied flowers because their growth is a measure of the reproductive health and overall growth of the forests, and because there is long-term data on flower production available," Pau said.

The amount of sunlight reaching tropical forests due to varying amounts of cloud cover is an important factor, just not the most important when it comes to flower production.

"Clouds are a huge uncertainty in understanding the impacts of climate change on tropical forests," Pau said. "Both sites still appear to respond positively to increases in light availability. Yet temperature was the most consistent factor across multiple time-scales.

"With most projections of future climate change, people have emphasized the impact on high-latitude ecosystems because that is where temperatures will increase the most," Pau said. "The tropics, which are already warm, probably won't experience as much of a increase as high-latitude regions. Even so, we're showing that these tropical forests are still really sensitive to small degrees of change."

Explore further: China insists wealthy countries should improve emission targets

More information: Paper: Clouds and temperature drive dynamic changes in tropical flower production, DOI: 10.1038/nclimate1934

Related Stories

Scientists discover that rainforests take the heat

May 30, 2013

South American rainforests thrived during three extreme global warming events in the past, say paleontologists at the Smithsonian Tropical Research Institute in a new report published in the Annual Review ...

Are tropical forests resilient to global warming?

Mar 10, 2013

Tropical forests are less likely to lose biomass – plants and plant material - in response to greenhouse gas emissions over the twenty-first century than may previously have been thought, suggests a study published online ...

Recommended for you

Rio's Olympic golf course in legal bunker

10 hours ago

The return of golf to the Olympics after what will be 112 years by the time Rio hosts South America's first Games in 2016 comes amid accusations environmental laws were got round to build the facility in ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

deatopmg
1.9 / 5 (12) Jul 08, 2013
It couldn't possibly be due to CO2 fertilization, could it?
deepsand
3.5 / 5 (11) Jul 08, 2013
Someone doesn't understand the issues re. temperatures vs. CO2 and their effects on plants very well.
Howhot
4.5 / 5 (8) Jul 08, 2013
If I was a forest, I would love the extra CO2! A natural response would be to grow more, Shorter winter times would increase the growing time and possible make for earlier blooms.
From the article
"It integrates ground and satellite observations over nearly three decades to tease apart the influence of temperature and cloudiness on local flower production,"
Apparently that has a big influence on growth.

There is a catch with this of course, that being the changing weather patterns created from adding more greenhouse gasses into the atmosphere and the global effects of that.