Cellon Oak: Can Trees Live Forever?

Cellon OakCellon Oak is the largest and maybe the oldest Live Oak tree in Florida but how old is she really?  Estimates range from 300-500 years old, maybe older.  There is no way to determine the age without killing the tree.  So her true age will remain a mystery.Follow Phillip@majikphil
What we do know is that she was around long before any human alive today and she will likely survive hundreds of years after we are all returned to stardust.  She is far enough inland that climate change (rising sea level) should not affect her and she is protected by her own park today.  Like other protected old trees in the South she has lightning rods and has been mildly engineered to support one of her huge trailing limbs that would have otherwise broken from the tree long ago.  Cellon Oak also appears extremely healthy, also like other very old, protected trees in the Deep South.

The huge 10+ acre manicured lawn around Cellon Oak can make the tree look kind of average, until you see a human adjacent to the tree for scale.  Then she is massive.

The size and scale of Cellon Oak kind of begs the question:  Can Trees Live Forever?  And of course there has been recent scientific research into the longevity of very old trees.  

For me, I like to think that these trees might live another 1000 years.  They give me hope for the earth that I might not have without them.  Humanity seems to find a way to destroy everything it touches so finding these very old survivors makes me feel like maybe we'll survive this epoch too.

One negative that I saw on two recent visits was the spread of development in the general area of LaCross, Florida (just north of Gainesville).  The urban sprawl of Gainesville now reaches out to tiny LaCross.

There is a massive beehive in one of the limb scars on the backside of Cellon Oak.  I've been visiting the tree for years and the hive is larger every year.  The bees' survival also gives me hope for nature's ability to survive.

Mammoth Oak is currently considered the Florida Challenger for largest live oak.  Mammoth Oak is located perilously close to US 441 in The Villages area of Central Florida.  If you notice in the image above the large powerlines along 441 are visible in the background.

While Mammoth Oak is in a protected area (Lake Griffin State Park), it does not benefit from lightning rods or other artificial supports and there are many competing trees around this giant.

A lot of the major limbs of Mammoth Oak have been trimmed off over the years, rather than propped up or wired up like other great old trees.  I visit Mammoth Oak several times a year and I have never encountered another hiker under her limbs, so I consider that a positive in terms of her long term survival.  She is also located relatively close to the guard station at the entrance to the state park.  I would hope she is close enough that a guard would notice any nefarious activities near the great tree.

Scientists are asking the same question about big and old trees:

Can Trees Live Forever?

Some trees can live for thousands of years, but we will not be around long enough to really know whether they can die of old age. 

Trees do not pay taxes. Some seem to avoid death as well. Many of the world’s most ancient organisms are trees, including a 3,600-year-old cypress in Chile and a sacred fig in Sri Lanka that was planted in the third century B.C. One bristlecone pine known as Methuselah has been alive for nearly five millenniums, standing in a forest in what is now called California.

But according to a Sergi Munné-Bosch paper published in the journal Trends in Plant Science, time ravages us all in the end. The paper, “Long-Lived Trees Are Not Immortal,” argues that even the most venerable trees have physiological limits — though we, with our succinct life spans, may never be able to tell.

We think Dr. Munné-Bosch is too cynical because none of us will live long enough to see if he really is correct, regardless, read more on his research below.

Said to be Tokyo's oldest Ginkgo Biloba tree at perhaps 750-1200 years old it is located on the grounds of the Zenpuku-ji Buddhist Temple.

Dr. Munné-Bosch, a plant biologist at the University of Barcelona, wrote the article in response to a January study on ginkgo trees, which can live for over a thousand years. The study found that 600-year-old ginkgos are as reproductively and photosynthetically vigorous as their 20-year-old peers. Genetic analysis of the trees’ vascular cambium — a thin layer of cells that lies just underneath the bark, and creates new living tissue — showed “no evidence of senescence,” or cell death, the authors wrote.

Dr. Munné-Bosch said he found the paper “very interesting,” but disagreed with how some readers of the study in popular media and beyond had interpreted it.

“In my opinion at least, there is no immortality,” he said.

Those tree species that can live for centuries or millenniums have a lot of tricks for staying youthful. They have simple body plans, and develop modularly, so they can replace parts they lose. They also build on their own dead tissue, which provides support and volume at a low metabolic cost. The trunk of a very old tree might be 95 percent dead, Dr. Munné-Bosch said, a strategy used also by other plants.

The remains of a giant sequoia that fell in Sequoia and Kings Canyon National Park in 2011.

For these reasons, it’s much more likely that such a tree will die of external causes than age-related ones. In some populations, this can result in “negative senescence” — a phenomenon where the durability of older trees means they actually have a greater chance of survival than younger ones, Dr. Munné-Bosch said.

Still, “everything seems to indicate” that individual trees are mortal, he said.

But others have a different take.

“A modular organism such as a tree could hypothetically live forever,” said Peter Brown, a forest scientist who runs an ancient tree database called the OldList. “I don’t think there is any real physiological or anatomical limitation for them not to just keep going.”

Bristlecone pines in the Twisted Forest near Brian Head, Utah. Some bristlecones are thousands of years old.Sean Gallup/Getty Images

In practice, though, “something always comes along” and interrupts, whether that’s a windstorm, a logging harvester or a swarm of bark beetles, or lightning, he said. Many trees on the OldList won the placement lottery, Dr. Brown said — they’re rooted deep into rocks, hard to get to with an ax, and far enough from other trees that pests can’t spread.

Dr. Munné-Bosch points to some potential limits. For instance, the vascular tissue that ginkgos produce gets thinner and thinner each year. At some point, it could become too thin to function, killing the tree, he said.

Ginkgos also suffer more physiological stress as time goes by, along with a depleted supply of growth hormone. Despite their miraculous vascular cambiums, “it’s probable that even ginkgo trees may die from ‘natural causes,’” said Richard Dixon, one of the authors of January’s ginkgo paper.

Dr. Brown and Dr. Munné-Bosch agree that the question is almost impossible to answer experimentally. Very old trees are rare, and the same tricks that allow for their long-term survival make them hard to find. (The oldest age group in the ginkgo study contained just three trees, all younger than 700.) So it’s difficult to design a comprehensive study on them.

Plus, our own life spans are simply too short. Even if a scientist dedicated her whole career to very old trees, she would be able to follow her research subjects for only a small percentage of their lives. And a long enough multigenerational study might see its own methods go obsolete.

For these reasons, Dr. Munné-Bosch thinks “we will never prove” whether long-lived trees experience senescence, he said. So in his own experimental work, he now focuses on shrubs with more manageable life spans, of around 30 years.

“I think at the end,” he said, “we have to accept that we will all die.”

The world's largest tree is the General Sherman, a Giant Sequoia.  The tree stands 275 feet tall and has a base of over 36 feet in diameter.Look for the men climbing (in red) on this Giant Sequoia. The tree is located in Sequoia and Kings Canyon National Park.

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