The world's most isolated tree has a radiocarbon spike in its 1965 growth ring marking peak nuclear testing. Some scientists propose using this as the formal start of the Anthropocene epoch, the moment humanity's impact became permanently recorded in living tissue worldwide.
A sentinel in the Southern Ocean
On Campbell Island, a remote outpost 700 kilometers south of New Zealand, stands a single Sitka spruce (Picea sitchensis). This organism holds the Guinness World Record for the "remotest tree" on Earth. Its nearest arboreal neighbor is over 222 kilometers away on the Auckland Islands. The species is native to the west coast of North America, from Alaska to California, making this specimen the only one known in the Southern Hemisphere. Its presence here is entirely artificial. Lord Ranfurly, the governor-general of New Zealand, is believed to have planted the spruce sometime between 1901 and 1907 during an expedition.
The tree survives in a harsh environment, battered by the winds of the "Furious Fifties" latitudes. Campbell Island receives rain on an average of 325 days per year, with gales occurring on 100 of those days. Despite these conditions, the spruce grows at a rate five to ten times faster than native shrubs. The tree is about 9 meters tall, but its shape is unusual, appearing more like a large cauliflower than a typical conifer. This is likely because staff from a former meteorological station on the island periodically cut its top off to use as a Christmas tree.
A record of the atomic age
The tree's remote location makes it an exceptional scientific instrument. In 2014, researchers extracted a core sample to analyze its growth rings. They were looking for a specific marker: a spike in atmospheric radiocarbon (Carbon-14). Above-ground thermonuclear weapons tests in the 1950s and early 1960s released large amounts of this isotope into the atmosphere. Plants absorb carbon through photosynthesis, meaning this "bomb spike" became recorded in living tissues worldwide.
The analysis, led by Chris Turney of the University of New South Wales, found a distinct peak in Carbon-14 within the tree's growth ring for the period between October and December 1965. This date marks the moment the radiocarbon pulse, which peaked in the Northern Hemisphere in 1964, fully circulated and reached the remote Southern Ocean. The presence of this clear, global signal in such an isolated organism shows the worldwide reach of human activity. Because Campbell Island is so far from industrial centers, the signal is unambiguous. This finding has led scientists to propose using the 1965 radiocarbon spike as the "golden spike"—a definitive global marker, or Global Boundary Stratotype Section and Point (GSSP)—for the beginning of the Anthropocene epoch.
💡Fun Facts
The tree is often called the "Ranfurly Tree" after Lord Ranfurly, the New Zealand governor who likely planted it in the early 20th century.
The tree is effectively sterile; as a solitary specimen, it has no mate for pollination and has never produced viable cones or seeds.
Campbell Island is a UNESCO World Heritage site, recognized for its unique flora, including large "megaherbs" with enormous leaves and flowers, and as an important breeding ground for the southern royal albatross.
Before this spruce gained the record, the world's most isolated tree was the Tree of Ténéré, an acacia in the Sahara Desert, which was destroyed by a truck driver in 1973.
Campbell Island is a protected National Nature Reserve. Access is strictly controlled by the New Zealand Department of Conservation and requires a special permit.
Admission
Visits are possible only via a small number of permitted expedition cruise operators. Prices for these multi-day voyages are substantial.
Accessibility
The island is reached by a sea journey of at least two days from mainland New Zealand through the notoriously rough Southern Ocean. Landings are by Zodiac boat, and the terrain is rugged and undeveloped.