Pando (tree)

Pando (or The Trembling Giant)cite web |url=http://discovermagazine.com/1993/oct/thetremblinggian285 |title=The Trembling Giant |accessdate=2008-05-08 |publisher=Discover Magazine |date=1993-10-01 |author=Grant, Michael C. ] is a clonal colony of a single male Quaking Aspen ("Populus tremuloides") tree located in the U.S. state of Utah, all determined to be part of a single living organism by identical genetic markers [ [http://www.fs.fed.us/newcentury/organism.htm Pando] by the National Park Service] and one massive underground root system. The plant is estimated to weigh collectively 6,000 tonnes (6,615 tons),cite paper
author = OECD Environment Directorate
title = Consensus Document on the Biology of "Populus" L. (Poplars)
publisher = OECD
year = 2000
url = http://www.olis.oecd.org/olis/2000doc.nsf/4f7adc214b91a685c12569fa005d0ee7/c125692700623b74c1256a0600551816/$FILE/JT00103743.DOC
format = Microsoft Word document
accessdate = 2006-10-08 ] making it the heaviest known organism.Genetic Variation and the Natural History of Quaking Aspen, Jeffry B. Mitton; Michael C. Grant, "BioScience", Vol. 46, No. 1. (Jan., 1996), pp. 25-31.] The root system of Pando is claimed by some to be among the oldest known living organisms in existence at 80,000 years of age, [ [http://www.nps.gov/brca/naturescience/quakingaspen.htm Quaking Aspen] by the Bryce Canyon National Park Service] though the method used to produce this estimate (an estimate on when climatic conditions were last suitable for seedling germination) is not supported by current evidence of germination.U.S. Forest Service Fire Effects Information System: [http://www.fs.fed.us/database/feis/plants/tree/poptre/all.html#BOTANICAL%20AND%20ECOLOGICAL%20CHARACTERISTICS "Populus tremuloides" botanical and ecological characteristics] ]

Name

The name "Pando" was chosen because it is Latin for "I spread", [cite journal
author = Research and Development Information Outreach, USDA Forest Service
date =
year = 1999
month = Fall
title = Quaking in Their Roots: The Decline of Quaking Aspen
journal = Natural Inquirer
volume = 2
issue = 1
pages = 7–11
doi =
id =
url = http://www.naturalinquirer.usda.gov/NIKids.cfm?act=viewarticle&issue=4&article=25
accessdate = 2006-10-08
publisher = US Department of Agriculture ] while the nickname "The Trembling Giant" can be attributed to the common name of "Populus tremuloides", the trembling aspen, whose leaves frequently rattle.

History

Pando is thought to have grown for much of its lifetime under ideal circumstances: frequent fires have prevented its main competitor, conifers, from colonizing the area, and climate change, transitioning from a wet and humid weather pattern to semi-arid, has obstructed widespread seedling establishment and the accompanying rivalry from younger aspens.

During intense fires, the organism survived by 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 is markedly different from that of today, and it may be as many as ten millennia since Pando's last successful flowering, according to an OECD report:Quote|Clonal groups of "P. tremuloides" in eastern North America are very common, but generally less than 0.1 ha in size, while in areas of Utah, groups as large as 80 ha have been observed (Kemperman and Barnes 1976). In the semi-arid western United States, some argue that widespread seedling establishment has not occurred since the last glaciation, some 10,000 years ago (Einspahr and Winton 1976, McDonough 1985). Indeed, some biologists feel that western clones could be as old as 1 million years (Barnes 1966, 1975). It has been claimed that a single clone, nicknamed "Pando" (Latin for "I spread"), covers 43 hectares, contains more than 47,000 stems and weighs in excess of 6 million kg, making it the largest known organism (Grant et al. 1992, Mitton and Grant 1996)|OECD|"Consensus Document on the Biology of "Populus" L. (Poplars)" However, others have observed that both flowering, and successful large-scale seedling establishment, occur frequently, even during dry years, in the modern period, invalidating the dating method.

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. 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." [ [http://www.usps.com/communications/news/stamps/2006/wash06downloads.htm Wonders of America: Land of Superlatives] at "usps.com"] In 2005 Lewis Libby wrote a letter to Judith Miller of the New York Times, who was jailed for refusing to reveal her sources in the White House, which used the Pando an allegory for teamwork.

Out West, where you vacation, the aspens will already be turning. They turn in clusters, because their roots connect them.

ize and age

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 technically, stems) is 130 years, as deciphered by tree rings. Michael Grant in "BioScience" said:

Debate

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, [ [http://www.nativetreesociety.org/measure/world_largest.htm Bob van Pelt] ] although no such stand is known to exist. 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, though the collective groups would remain the same singular, genetic individual.

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 climates 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. [Kay, Charles E. (1993). Aspen seedlings in recently burned areas of Grand Teton and Yellowstone National Parks. "Northwest Science". 67(2): 94-104.] J. L. Howard (U.S. Forest Service "Fire Effects Information System") states:

Other candidates for oldest living organism include possibly older fungal mats in Oregon, older Creosote Bushes, and strands of the marine plant "Posidonia oceanica" in the Mediterranean Sea.

Location

Pando lives in Fishlake National Forest, near Fish Lake on the Fish Lake Plateau located at the western edge of the Colorado Plateau in South-central Utah.

ee also

*Largest organism
*List of long-living organisms
*Vegetative reproduction
*Genet/Ramet
*Rhizome
*Basal shoot

References