The world's loneliest tree stands on an island 700 kilometres south of New Zealand. Sitka spruce on uninhabited Campbell Island is considered the "world's loneliest tree". A team of researchers in New Zealand says that this tree will help to find the secrets of climate change.
The nine-meter-tall mushroom holds the Guinness World Record for the "farthest tree" on Earth. It is the only tree on the scrubby, windswept island in the Southern Ocean, 700 km south of New Zealand. It is the only tree within a radius of 222 km; Its nearest neighbour grows in the Auckland Islands.
Prior to the Campbell Island spruce, the Tree of the Ténéré in Niger was said to be the most isolated tree on the planet, until it was killed by a driver in 1973.
It is believed that the Sitka spruce was planted by Lord Ranfurly, New Zealand's then governor, in the early 1900s – hence its nickname the Ranfurly tree.
Studies have not been able to confirm its exact age, however, and Guinness World Records notes that although it is popularly referred to as the world's loneliest tree, "there is no universally recognized precise definition of what constitutes a 'tree'".
It is also classified as an invasive species and some scientists would be happy to see it go. But for radiocarbon science leader at GNS Science, Dr Jocelyn Turnbull, the tree could be a valuable tool to understand what is happening with the uptake of carbon dioxide in the Southern Ocean.
"Of the CO2 that we produce from burning fossil fuels and put into the atmosphere, only about half stays there and the other half goes into the land and the ocean," Turnbull said.
"It turns out the Southern Ocean - one of those carbon sinks - has taken up about 10% of all the emissions that we have produced over the last 150 years."
Turnbull has been working with New Zealand's Deep South National Science Challenge, the Antarctic Science Platform and the National Institute for Water and Atmospherics to understand what is happening to carbon in the Southern Ocean.
"You can't collect air that was there 30 years ago, because it is not there anymore," Turnbull said.
“So we came up with this idea of using tree rings. Plants, when they grow take carbon dioxide out of the air by photosynthesis and they use that to grow their structures and the carbon from the air ends up in the tree rings.”
This is helpful when there is an abundance of established trees, but those are a rarity in the Southern Ocean. Enter the Sitka spruce – the southernmost tree the team could find that would offer up good data. "It's grown a lot faster than anything else [in that region] and the rings are bigger and easier to separate out and get a record from."