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Pando (tree)
Encyclopedia
Pando is a clonal colony
of a single male Quaking Aspen
(Populus tremuloides) located in the U.S. state
of Utah
, all determined to be part of a single living organism by identical genetic markers and one massive underground root system
, although whether it is a single tree
is disputed. The plant is estimated to weigh collectively 6,000,000 kg (6,600 short ton
s), making it the heaviest known organism
. The root system of Pando is estimated to be among the oldest known living organisms in existence at 80,000 years of age.
Pando is located in the Fishlake National Forest
, near Fish Lake
on the Fish Lake Plateau located at the western edge of the Colorado Plateau
in South-central Utah. The name "Pando" was chosen because it is Latin
for "I spread."
Pando is thought to have grown for much of its lifetime under ideal circumstances: frequent forest fires have prevented its main competitor, conifers
, from colonizing the area, and climate change, shifting from a wet and humid weather pattern to a semi-arid one, has obstructed widespread seedling establishment and the accompanying rivalry from younger aspens.
During intense fires, the organism survived underground, with its root system sending up new stems in the aftermath of each wildfire. If its postulated age is correct, the climate into which Pando was born was markedly different from that of today, and it may be as many as 10,000 years since Pando's last successful flowering, according to an Organisation for Economic Co-operation and Development
(OECD) report:
Pando was discovered by Burton V. Barnes of the University of Michigan in the 1970s. Barnes was widely considered an expert on North American aspen at the time, having been one of the first to describe the clonal growth of aspen from an extensive root system as part of his dissertation at Michigan in the late 1950s. Barnes had described Pando as a single organism based on its morphological characteristics. Building on Barnes's earlier work, Michael Grant of the University of Colorado at Boulder
re-examined Pando and claimed it to be the world's most massive organism in 1992.
In 2006 the United States Postal Service
made a stamp in commemoration of the aspen, calling it one of the forty "Wonders of America."
The clonal colony encompasses 43 hectares (107 acres) and has around 47,000 stems, which continually die and are renewed by its roots. Many of the stems are connected by its root system. The average age of Pando's trunks, or stems, is 130 years, as deciphered by tree rings. Michael Grant
in BioScience
said:
Some experts speculate that Pando's reign since 1992 as the heaviest-known organism may be short lived. Less well-studied Quaking Aspens in Utah may be 80 hectares in extent and one million years old. Other large colonies could exist elsewhere. A clonal colony of at least seven Coastal Redwoods could weigh more, though no such stand has been systematically sought and identified yet. Other scientists think that portions of Pando's root system may be dead and might have led the plant to split into separate groups and therefore would not be one organism.
Tree experts also note that the organism's age cannot be determined with the level of precision found in tree rings; some claim Pando's age is closer to 1 million years. Its current 80,000 year designation is based on a complex set of factors including the history of its local environment such as: The evidence indicating that there are few if any naturally occurring new aspens in most of the western United States
since a climate shift took place 10,000 years ago and eliminated favorable soil conditions for seedlings; the rate of growth (including the differences of rates in distinct climate
s when accounting for its local-climate history, that males grow slower than females, and that aspens grow slower at higher elevations – Pando is at 2697 m, or 8,848 ft, above sea level); its size; and its genetic code
in comparison to the mutations found among aspens born in the modern era. Michael Grant summed it thus:
This is however not supported by other observations in the region, which show that seedling establishment of new clones is regular, and often abundant on sites exposed by wildfire
. J. L. Howard (U.S. Forest Service Fire Effects Information System) states:
Other candidates for oldest or heaviest living organisms include the possibly larger fungal mats
in Oregon
, the ancient clonal Creosote bush
es, and strands of the clonal marine plant Posidonia oceanica
in the Mediterranean Sea
.
Clonal colony
A clonal colony or genet is a group of genetically identical individuals that have grown in a given location, all originating vegetatively from a single ancestor. In plants, an individual in such a population is referred to as a ramet...
of a single male Quaking Aspen
Populus tremuloides
Populus tremuloides is a deciduous tree native to cooler areas of North America, commonly called quaking aspen, trembling aspen, American aspen, and Quakies,. The trees have tall trunks, up to 25 metres, with smooth pale bark, scarred with black. The glossy green leaves, dull beneath, become golden...
(Populus tremuloides) located in the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
of Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
, all determined to be part of a single living organism by identical genetic markers and one massive underground root system
Root
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...
, although whether it is a single tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
is disputed. The plant is estimated to weigh collectively 6,000,000 kg (6,600 short ton
Ton
The ton is a unit of measure. It has a long history and has acquired a number of meanings and uses over the years. It is used principally as a unit of weight, and as a unit of volume. It can also be used as a measure of energy, for truck classification, or as a colloquial term.It is derived from...
s), making it the heaviest known organism
Largest organisms
The largest organism found on Earth can be measured using a variety of methods. It could be defined as the largest by volume, mass, height or length. Some organisms group together to form a superorganism, though this cannot truly be classed as one large organism...
. The root system of Pando is estimated to be among the oldest known living organisms in existence at 80,000 years of age.
Pando is located in the Fishlake National Forest
Fishlake National Forest
Fishlake National Forest is located in south central Utah, USA. Its namesake is the largest freshwater mountain lake in the state.-Geography:...
, near Fish Lake
Fish Lake, Utah
Fish Lake is a high alpine lake located in the Fishlake/ Southern Wasatch Plateau region of south-central Utah, United States. It lies within and is the namesake of the Fishlake National Forest....
on the Fish Lake Plateau located at the western edge of the Colorado Plateau
Colorado Plateau
The Colorado Plateau, also called the Colorado Plateau Province, is a physiographic region of the Intermontane Plateaus, roughly centered on the Four Corners region of the southwestern United States. The province covers an area of 337,000 km2 within western Colorado, northwestern New Mexico,...
in South-central Utah. The name "Pando" was chosen because it is Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
for "I spread."
History
Pinophyta
The conifers, division Pinophyta, also known as division Coniferophyta or Coniferae, are one of 13 or 14 division level taxa within the Kingdom Plantae. Pinophytes are gymnosperms. They are cone-bearing seed plants with vascular tissue; all extant conifers are woody plants, the great majority being...
, from colonizing the area, and climate change, shifting from a wet and humid weather pattern to a semi-arid one, has obstructed widespread seedling establishment and the accompanying rivalry from younger aspens.
During intense fires, the organism survived underground, with its root system sending up new stems in the aftermath of each wildfire. If its postulated age is correct, the climate into which Pando was born was markedly different from that of today, and it may be as many as 10,000 years since Pando's last successful flowering, according to an Organisation for Economic Co-operation and Development
Organisation for Economic Co-operation and Development
The Organisation for Economic Co-operation and Development is an international economic organisation of 34 countries founded in 1961 to stimulate economic progress and world trade...
(OECD) report:
Pando was discovered by Burton V. Barnes of the University of Michigan in the 1970s. Barnes was widely considered an expert on North American aspen at the time, having been one of the first to describe the clonal growth of aspen from an extensive root system as part of his dissertation at Michigan in the late 1950s. Barnes had described Pando as a single organism based on its morphological characteristics. Building on Barnes's earlier work, Michael Grant of the University of Colorado at Boulder
University of Colorado at Boulder
The University of Colorado Boulder is a public research university located in Boulder, Colorado...
re-examined Pando and claimed it to be the world's most massive organism in 1992.
In 2006 the United States Postal Service
United States Postal Service
The United States Postal Service is an independent agency of the United States government responsible for providing postal service in the United States...
made a stamp in commemoration of the aspen, calling it one of the forty "Wonders of America."
Size and age
Michael Grant
Michael Grant may refer to:* Michael Grant, 12th Baron de Longueuil , nobleman possessing the only French colonial title recognized by the King or Queen of Canada* Michael Grant , American football player...
in BioScience
BioScience
BioScience is a peer-reviewed monthly sometimes daily scientific journal that is published by the American Institute of Biological Sciences . The content is written and edited for accessibility to researchers, educators, and students alike...
said:
Debate
Tree experts also note that the organism's age cannot be determined with the level of precision found in tree rings; some claim Pando's age is closer to 1 million years. Its current 80,000 year designation is based on a complex set of factors including the history of its local environment such as: The evidence indicating that there are few if any naturally occurring new aspens in most of the western United States
Western United States
.The Western United States, commonly referred to as the American West or simply "the West," traditionally refers to the region comprising the westernmost states of the United States. Because the U.S. expanded westward after its founding, the meaning of the West has evolved over time...
since a climate shift took place 10,000 years ago and eliminated favorable soil conditions for seedlings; the rate of growth (including the differences of rates in distinct climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
s when accounting for its local-climate history, that males grow slower than females, and that aspens grow slower at higher elevations – Pando is at 2697 m, or 8,848 ft, above sea level); its size; and its genetic code
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
in comparison to the mutations found among aspens born in the modern era. Michael Grant summed it thus:
This is however not supported by other observations in the region, which show that seedling establishment of new clones is regular, and often abundant on sites exposed by wildfire
Wildfire
A wildfire is any uncontrolled fire in combustible vegetation that occurs in the countryside or a wilderness area. Other names such as brush fire, bushfire, forest fire, desert fire, grass fire, hill fire, squirrel fire, vegetation fire, veldfire, and wilkjjofire may be used to describe the same...
. J. L. Howard (U.S. Forest Service Fire Effects Information System) states:
Other candidates for oldest or heaviest living organisms include the possibly larger fungal mats
Armillaria ostoyae
Armillaria solidipes is a species of fungus in the Physalacriaceae family. It is the most common variant in the western U.S., of the group of species that all used to share the name Armillaria mellea. Armillaria solidipes is quite common on both hardwood and conifer wood in forests west of the...
in Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, the ancient clonal Creosote bush
Creosote bush
Larrea tridentata is known as Creosote bush as a plant, chaparral as a medicinal herb, and as "gobernadora" in Mexico, Spanish for "governess," due to its ability for inhibiting the growth of nearby plants to have more water. In Sonora, it is more commonly called "hediondilla." It is a flowering...
es, and strands of the clonal marine plant Posidonia oceanica
Posidonia oceanica
Posidonia oceanica is a seagrass species that is endemic to the Mediterranean Sea. It forms large underwater meadows that are an important part of the ecosystem. The fruit is free floating and known in Italy as 'the olive of the sea'...
in the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
.
See also
- Basal shootBasal shootA basal shoot, root sprout, adventitious shoot, water sprout or sucker is a shoot or cane which grows from a bud at the base of a tree or shrub or from its roots. This shoot then becomes, or takes the form of, a singular plant. A plant that produces suckers is referred to as surculose...
- Genet/Ramet
- Largest organism
- List of long-living organisms
- RhizomeRhizomeIn botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
- Vegetative reproductionVegetative reproductionVegetative reproduction is a form of asexual reproduction in plants. It is a process by which new individuals arise without production of seeds or spores...