Aging in a long-lived clonal tree

Aspen clones — genetically identical stands spreading from a single individual — were sized and dated by genetic methods, and pollen viability was measured across clones of different estimated age.

Studied in

Populus tremuloides

Sample size

aspen clones of differing estimated ages

Older, larger clones produced markedly less viable pollen. Reproductive performance declined with the age of the genetic individual even though the stems themselves were young.

• Clone ages are estimated from size and growth rate, with wide uncertainty.
• One species; the rate of somatic mutation accumulation will differ elsewhere.
• Shows a decline in pollen viability, not the full reproductive or survival consequence.

• Asking how old a forest of one tree is

  Does a clonal tree that keeps growing new stems escape ageing altogether?

• Trees

  The oldest tree in the world depends entirely on whether you are counting a trunk or a lineage.

• Fungi

  The largest known organism is a fungus — if you accept that a genetically identical mycelium spread over 9 square kilometres is one individual.