Old Tjikko
Old Tjikko is a Norway spruce on Fulufjället in Sweden whose living trunk is young but whose root system has been estimated at about 9,560 years old.
Clonal colony: A group of genetically identical organisms produced through vegetative reproduction from a shared ancestor. Old Tjikko’s trunk is one shoot in a clone sustained by roots and successive regrowth.
Fulufjället National Park: A protected mountain landscape in Dalarna, Sweden, established as a national park in 2002. Old Tjikko grows on this mountain plateau.
Methuselah (tree): A Great Basin bristlecone pine in California, among the oldest known non-clonal trees with a verified age. Methuselah’s age is counted from its living trunk, unlike Old Tjikko’s clonal root age.
Biological individuality: The problem of defining an individual organism, especially when bodies grow, divide, or remain genetically connected. The age attributed to Old Tjikko depends on treating its connected root system as one individual.
Vegetative reproduction: A form of asexual reproduction in plants that produces new individuals from stems, roots, leaves, or other vegetative parts. New spruce stems can arise from the older plant without seeds.
Dendrochronology: The dating and study of past events using patterns in tree rings. Tree rings date the trunk’s growth, but not the full age claimed for its roots.
Pando (tree): A vast clonal colony of quaking aspen in Utah, often described as a single organism. Pando is another ancient plant clone, but it spreads across a much larger stand.
Ramet: A potentially independent physical unit of a clonal organism, such as a shoot arising from a shared genetic individual. The visible trunk is a ramet whose lifespan is far shorter than the clone’s estimated age.
Layering: A plant propagation process in which a stem forms roots while still attached to its parent plant. Branches touching the ground can root and help the spruce persist through changing conditions.
Radiocarbon dating: A method for estimating the age of once-living material by measuring its carbon-14 content. Carbon dating of root-system remains underlies the reported millennia-old age.