Pando Aspen: A huge, ancient clonal tree spanning millennia

A recent study has provided new insights about Pando, the colossal trembling aspen clone in Fishlake National Forest, Utah, suggesting that this enormous organism could be as old as 80,000 years. The study, conducted by Rozenn Pineau, a researcher at Utah State University, reveals Pando’s potential age by examining its unique clonal growth pattern and genetic mutations, suggesting the organism may have grown since the earliest human migrations out of Africa . The study, currently posted on bioRxiv for peer review, examines the mutation rate in Pando’s genome, with estimates ranging between 16,000 and 80,000 years.

The largest living organism in the world

Pando, which means ‘I spread’ in Latin, holds the title of the world’s largest organism, covering an area of ​​over 40 hectares and containing approximately 47,000 stems. This enormous clonal colony developed from a single root system connecting each stem, making Pando not only a vast area, but also the heaviest living organism on the planet. According to According to Paul Rogers, director of the Western Aspen Alliance, the genetic continuity of the aspen’s root system allows it to withstand environmental changes. Rogers noted that no previous study had confirmed Pando’s age, making this study an important milestone in understanding the organism’s ancient origins.

Genetic findings and ecological challenges

Pineau’s research highlights that Pando’s mutational spread is less than expected, with nearby stems showing limited genetic diversity despite spatial proximity. This suggests a surprising level of genetic stability in Pando, even over thousands of years. While analyzing pollen from a nearby lakebed, researchers noted that aspen pollen has consistently appeared in sediment for more than 60,000 years, possibly confirming Pando’s ancient presence in the area.

To counter the threats from deer and cattle grazing, conservation measures have been implemented, with fenced areas now protecting parts of the forest. Rogers noted encouraging signs of recovery during a recent visit, suggesting the fencing and favorable rainfall could aid Pando’s recovery.