structural:reformatting
Old Tjikko is an approximately 9,566 years-old Norway spruce, located in the Dalarna province in Sweden. Old Tjikko originally gained fame as the "world's oldest tree". Old Tjikko is, however, a clonal tree that has regenerated new trunks, branches and roots over millennia rather than an individual tree of great age. Old Tjikko is recognized as the oldest living Picea abies and the fourth-oldest known clonal tree. The age of the tree was determined by carbon dating of genetically matched plant material collected from under the tree, as dendrochronology does not work for clonal trees. The trunk itself is estimated to be only a few centuries old, but the plant has survived for much longer due to a process known as layering, or vegetative cloning.