Navigation Links
New study reveals unexpected relationship between climate warming and advancing treelines
Date:8/12/2009

A new study reveals that treelines are not responding to climate warming as expected. The research, the first global quantitative assessment of the relationship between climate warming and treeline advance, is published in Ecology Letters and tests the premise that treelines are globally advancing in response to climate warming since 1900.

Treelines are the elevation or latitudinal limits where trees are capable of growth or survival and are considered to be early indicators of climate warming because they are constrained primarily by cold temperatures. Summer temperature is widely considered to be the primary control of treeline formation and maintenance, whereas winter temperatures have previously been considered less critical because of the insulative effects of snow. This study reveals how winter warming has overturned this prevailing view.

"Average temperatures have risen over the last century, with a more pronounced and rapid change at high altitudes and latitudes", said Ms. Melanie Harsch from the Bio-Protection Research Centre in New Zealand. "Within these zones, treelines are thought to be more temperature sensitive and so the rise in summer temperatures should result in an advance of treeline position."

Harsch and her co-authors conducted a multivariate meta-analysis, using a global dataset of 166 treeline sites with temperature data taken from the closest climate station to each site. The team used this data to analyse treeline advance throughout the 20th century and consider the contributing factors to that advance.

The team found that only 87 of the 166 sites (52%) had advanced while simultaneously the mean annual local temperatures had increased at 111 of the 166 sites at an average rate of 0.013˚C a year (or 1˚C in 77 years). Of the remaining sites, 77 (47%) remained stable and only two (1%) had treelines that receded. Both of the receding sites showed evidence of disturbance, indicating that regardless of form, location or degree of temperature change experienced over the last century, treeline positions have either advanced or remained static.

"Surprisingly these results reveal that treelines are not universally responding to climate warming by advancing, as expected," said Harsch, "However they demonstrate the importance of temperature on treeline advance over other factors such as disturbance, latitude, scale, elevation and distance to the ocean; none of which demonstrated strong relationships with the probability of treeline advance."

Another surprising result of this study was the association with winter, rather than summer, warming. These results provide no evidence of the prevailing view that high altitude and latitude treelines are controlled only by summer temperatures. Instead they show that treelines are more likely to advance at sites that had warmed during the winter months. It is known, at least in northern latitudes that climate-associated changes in winter conditions are on average more extreme than changes in summer conditions.

"These results show that treelines are responding to warming, but are not consistent in that only half of the sites showed signs of advance despite most sites experiencing warming. Several studies on plant species' responses to climate warming have shown mixed results and this study provides a possible explanation both winter and summer conditions control treeline position," concluded Harsch. "Our expectations of response depend upon which factors are limiting the current treeline distribution. Where summer temperature is the primary limiting factor we can expect to continue seeing advance, but at other sites treeline advance is unlikely to occur until other limiting factors are first lessened."


'/>"/>

Contact: Ben Norman
Benorman@wiley.com
44-012-437-70375
Wiley-Blackwell
Source:Eurekalert

Related biology news :

1. Childhood obesity indicates greater risk of school absenteeism, Penn study reveals
2. A study by the MUHC and McGill University opens a new door to understanding cancer
3. Study begins to reveal clues to the cause and progression of sepsis
4. Clones on task serve greater good, evolutionary study shows
5. New study warns limited carbon market puts 20 percent of tropical forest at risk
6. New study examines how rearing environment can alter navigation
7. Study links cat disease to flame retardants in furniture and to pet food
8. New continent and species discovered in Atlantic study
9. Study shows link between alcohol consumption and hiv disease progression
10. Feeling hot, hot, hot: New study suggests ways to control fever-induced seizures
11. Study finds environmental tests help predict hospital-acquired Legionnaires disease risk
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/3/2016)... 2016 Das DOTM ... Nepal hat ein 44 Millionen ... Kennzeichen, einschließlich Personalisierung, Registrierung und IT-Infrastruktur, an ... und Implementierung von Identitätsmanagementlösungen. Zahlreiche renommierte internationale ... teilgenommen, aber Decatur wurde als konformste und ...
(Date:5/24/2016)... May 24, 2016 Ampronix facilitates superior patient care by providing unparalleled technology ... LCD display is the latest premium product recently added to the range of products ... ... ... 3d Imaging- LCD Medical Display- Ampronix News ...
(Date:5/3/2016)... 3, 2016  Neurotechnology, a provider of high-precision ... Automated Biometric Identification System (ABIS) , a complete ... MegaMatcher ABIS can process multiple complex biometric transactions ... of fingerprint, face or iris biometrics. It leverages ... and MegaMatcher Accelerator , which have been ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... June 23, 2016 , ... UAS LifeSciences, one of ... their brand, UP4™ Probiotics, into Target stores nationwide. The company, which has been ... Target to its list of well-respected retailers. This list includes such fine stores ...
(Date:6/23/2016)... 2016 Houston Methodist Willowbrook Hospital has ... Association to serve as their official health care ... Willowbrook will provide sponsorship support, athletic training services, ... coaches, volunteers, athletes and families. "We ... Association and to bring Houston Methodist quality services ...
(Date:6/23/2016)... FRANCISCO , June 23, 2016   EpiBiome ... has secured $1 million in debt financing from Silicon ... ramp up automation and to advance its drug development ... its new facility. "SVB has been an ... beyond the services a traditional bank would provide," said ...
(Date:6/23/2016)... Apellis Pharmaceuticals, Inc. today announced positive ... its complement C3 inhibitor, APL-2. The trials were ... studies designed to assess the safety, tolerability, pharmacokinetics ... healthy adult volunteers. Forty subjects were ... dose (ranging from 45 to 1,440mg) or repeated ...
Breaking Biology Technology: