Monday, January 11, 2010

 Oldest Living Palmer's Oak- Jurupa Oak sets world record

 Jurupa Mountains, Calif., USA -- The Jurupa Oak, which belongs to the species Quercus palmeri or Palmer's Oak, has been around for 13,000 years , setting the world record for the oldest living Palmer's Oak.

   Photo: Professor Jeffrey Ross-Ibarra with the Jurupa Oak that grows by cloning itself. (enlarge photo)

   That's 1,000 years older than a previously identified Palm Springs creosote bush that was thought to be the oldest plant in California, 8,000 years older than bristlecone pines and 10,000 years older than the redwoods.

   The oak is made up of a community of cloned bushes and scientists believe it has managed to survive the extreme effects of climate change by regenerating.

   “Ring counts show that the Jurupa Oak is growing extremely slowly,” stated UC Davis student Michael May. “At its current rate of about 1/20th of an inch (1.27mm) per year, it would have taken at least 13,000 years for the clone to reach its current size. And it could be much older.”

  That means the Oldest Living Palmer's Oak has been standing on that hillside “through massive biotic changes”, says co-author Dr Andrew Sanders. “This literally appears to be a last living remnant of a vanished woody vegetation that occupied the inland valleys at the height of the Ice Age.”

  The Jurupa Oak, which belongs to the species Quercus palmeri or Palmer's Oak, is named after the windswept Jurupa hills where it lives.

   This species of trees usually occur in cooler and wetter regions. The strange location of the Jurupa was the first clue for the team that it might have unusual origins.

   “Palmer’s Oak normally occurs at much higher elevations, in cooler, wetter climates. In contrast, the Jurupa Oak scrapes by in dry chaparral, wedged between granite boulders and stunted by high winds, atop a small hill in plain sight of suburban backyards,” said Professor Jeffrey Ross-Ibarra of the University of California Davis.

   Study leader, Jeffrey Ross-Ibarra, said: 'Palmer’s Oak normally occurs at much higher elevations, in cooler, wetter climates.

   'In contrast, the Jurupa Oak scrapes by in dry chaparral, wedged between granite boulders and stunted by high winds, atop a small hill in plain sight of suburban backyards.'

   The team also discovered that the oak didn't produce any fertile acorns, suggesting an unconventional form of growth.

   Genetic testing revealed the tangled cluster of stems was in fact a single individual, according to their study published in online journal PLoS ONE.

   Clonal growth occurs after a fire, when resprouts form around the base of burned stems. Over time, wood in the centre degrades, and new resprouts form after additional fires, leaving behind the haphazard collection of stems visible today.

   Because no new stems arise from acorns, the organism can only have achieved its current size - more than 25 yards long - through this method of resprouting.

   Scientists from the University of California were therefore able to work out the age of the clone by estimating its rate of growth from the rings in the stems.

   Co-author Andrew Sanders, said: 'This literally appears to be a last living remnant of a vanished woody vegetation that occupied the inland valleys at the height of the Ice Age.'

   Related world records:  Nature world records

   Monday, January 11, 2010