“He is alone on this windswept, low-vegetated island in the Southern Ocean, 700 kilometers south of New Zealand.” The Sitka spruce evoked by The Guardian has made a place for itself within the Guinness World Records in his capacity as“the most isolated tree on the planet”, says the British newspaper.
Its nearest neighbor grows 222 kilometers away, on the Auckland Islands, another uninhabited New Zealand archipelago.
The solitary, 30-foot-tall tree, believed to have been planted by Lord Ranfurly, a Briton who served as Governor of New Zealand from 1897 to 1904, “could help solve some climate change puzzles”, according to a team of New Zealand researchers. Specifically, this spruce could help to better understand the process of carbon dioxide absorption in the Southern Ocean.
Where did the CO go?2 ?
In 2016, researchers extracted a 5 millimeter carrot from the tree to carry out a study, the results of which have not yet been released. The analysis of these tree rings should allow them to assess the amount of CO2 stored in wood. Jocelyn Turnbull, carbon-14 dating specialist at GNS Science, the new zealand institute geological and nuclear sciences, reminds us that only half of the carbon dioxide emitted by the use of fossil fuels remains in the atmosphere. The other half goes into the oceans and soils.
“It turns out that the Southern Ocean is a carbon sink and has absorbed about 10% of the CO2 emitted by man over the past hundred and fifty years”, notes the researcher. But, raise The Guardian: “Previous studies looking at carbon uptake by the Southern Ocean have produced conflicting results.”
In general, atmospheric sampling is the best method for measuring CO concentrations.2, “but we cannot collect the air that was there thirty years ago”, observes Jocelyn Turnbull. That’s why she and her team turned to tree rings, especially those of Campbell’s Island spruce (see video below), “the southernmost tree the team could find”. The researcher points out:
“He grew much faster than anything else [dans cette région]and the rings are larger and easier to separate.”
The data it will provide may enable researchers to answer some of their questions: what is the absorption capacity of carbon sinks? Can we help them absorb more CO2 ?
Anyway, concludes the British newspaper, “Lately, the Sitka spruce, accustomed to his desert island, must feel less alone”.