The oldest known tree has been found in a mountainous region of Sweden, near the country’s border with Norway. According to scientists at Umeå University, the newest claimant to the “oldest tree” throne is 9,500 years old.

The Norway spruce is the fourth generation of a much older ancestral tree. Spruce trees can generate through root branches, producing genetically identical clones. Each successive trunk can survive about 600 years. As the previous one dies, a new stem may emerge from the roots, much like redwoods and some other conifers. In the same area, other spruces have been dated at more than 8,000 years old. Fulu Mountain in Dalarna is the site of this auspicious discovery.

The Norway spruce is an important conifer in Europe. A hardy and resilient tree, it can accommodate all but the driest climates. It also tolerates high winds and tends to be quite disease resistant. Often fast-growing, Norway spruces are used in the timber industry and with reforestation projects. As a result, they thrive throughout much of the world, and have been popular as a Christmas tree variety. However, because the needles tend to drop soon after cutting, these trees are less commonly sold in recent years. The bark is resinous and exudes burgundy pitch, which is used in varnish and other applications.

For years, the oldest trees were thought to be North American bristlecone pines, at 4,500 to 5,000 years old. Both kinds of ancient tree are relatively small, existing for millennia as almost bush-like individuals. But recent warming trends have caused the Swedish spruces to grow more rapidly - probably contributing to the discovery by making the trees more obvious. Most Norway spruces can grow to be very large, depending on soil type and other growing conditions.

Tree ages are established through carbon-14 dating. Plants take in carbon dioxide and incorporate the carbon atoms into their tissues. By measuring the amount of radioactive carbon-14 - one of the normally occurring forms - it is possible to calculate the time since the material was alive (and taking in new carbon).

Understanding the qualities that make some tree species more long-lived and tenacious can inform forestry and conservation practices. In this case, the ability to produce new main trunks has enabled spruce trees to withstand fluctuating climate conditions.