Prometheus (tree)
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Prometheus (aka WPN-114) is the nickname given to the oldest non-clonal organism ever known, a Great Basin Bristlecone Pine (Pinus longaeva) tree about 5000 years old growing at treeline on a mountain in eastern Nevada, USA. The tree was cut down on August 6, 1964 by a graduate student and U.S. Forest Service personnel for research purposes, though at the time they did not know of its world-record age. The cutting of the tree remains controversial. Different versions of the event and the decision-making process behind it exist, although a number of basic facts are agreed upon. The name refers to the mythological figure Prometheus, who stole fire from the gods and gave it to man.
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[edit] About the tree
The tree was a member of a population of bristlecone pine trees growing at treeline on the lateral moraine of a former glacier on Wheeler Peak, in what, since 1986, has been Great Basin National Park, in eastern Nevada. Wheeler Peak is the tallest mountain in the Snake Range, and the tallest mountain entirely within the state of Nevada. The bristlecone pine population on it is divided into (at least) two distinct sub-populations, one of which is accessible by a popular interpretive trail. Prometheus however, grew in an area reachable only by off-trail hiking. In either 1958 or 1961, a group of naturalists who admired the grove in which the tree grew gave names to a number of the largest or most distinctive trees, including Prometheus[1]. The designation of WPN-114 was given by the original researcher, Donald R. Currey, and refers to the 114th tree sampled by him for his research in Nevada's White Pine county.
The ring count of a section of the tree by Currey was 4844. A few years later, this was increased to 4862 by Donald Graybill of the University of Arizona's Laboratory of Tree-Ring Research. However, the ring counts were done on a trunk cross section taken about 2.5 m (8 feet) above the original germination point of the tree, because the innermost rings were missing below that point. Adding in the years required to reach this height, plus a correction for the estimated number of missing rings (which are not uncommon in trees growing at treeline), it is probable that the tree was at least 5000 years old when cut. This makes it the oldest unitary (i.e non-clonal) organism ever known, exceeding the Methuselah tree of the White Mountains' Schulman Grove, in California by about 200 years.
Whether Prometheus should be considered the oldest organism ever known depends on the definition of "oldest" and "organism" one uses. For example, certain sprouting or clonal organisms, such as creosote bush or aspen, could have older individuals if the entire clonal organism is considered. Under this standard, the oldest living organism is a quaking aspen grove in Utah known as Pando, at 80,000 years old. In a clonal organism, however, the individual clonal stems are nowhere near as old, and no part of the organism at any given point in time is particularly old. Prometheus was thus the oldest non-clonal organism yet discovered, with its innermost wood over 5000 years of age. It is possible, however, that an older specimen occurs that has not yet been aged. Bristlecones are notoriously hard to age because of their extremely contorted growth, and cutting of old trees is no longer allowed.
[edit] The cutting of the tree
In the 1950s dendrochronologists were making active efforts at finding the oldest living tree species, in order to use the analysis of the rings for various research purposes, such as the evaluation of former climates, the dating of archaeological ruins, and the basic question of finding the oldest living things. Bristlecone pines in the White Mountains of California and elsewhere were discovered by Edward Schulman to be older than any species yet dated. This spurred interest in finding very old bristlecones, possibly older than the Methuselah tree, aged by Schulman in 1957 at over 4700 years.
Donald R. Currey was a graduate student at the University of North Carolina at Chapel Hill studying the climate dynamics of the Little Ice Age using dendrochronology techniques. In 1963 he became aware of the bristlecone populations in the Snake Range and on Wheeler Peak in particular. Based on the size, growth rate and growth forms of some of the trees he became convinced that some very old specimens existed on the mountain, and cored some of them, finding trees exceeding 3000 years. Currey was not, however, able to obtain a continuous series of overlapping cores from WPN-114. Here, stories diverge. It is not clear whether Currey requested, or Forest Service personnel suggested, that he cut and section the tree in lieu of being able to core it. There is also some uncertainty as to why a core sample could not be obtained. One version has it that he broke or lodged his only long increment borer and could not obtain another before the end of the field season, another claims he broke two of them, while another implies that a core sample was too difficult to obtain and also would not provide as much definitive information as a full cross section of the tree would [2].
In addition, there are conflicting views over the uniqueness of Prometheus in the Wheeler Peak grove. It is reported that Currey and/or the Forest Service personnel who authorized the cutting believed the tree was just one of many large, very old trees in the grove, while others, at least one of whom was involved in the decision-making and tree cutting, believe that the tree was clearly unique — obviously older than other trees in the area. At least one person involved says that Currey knew this to be true at the time, although there is no known admission from Currey himself that he knew this, and others have disputed that the tree was obviously older than others [3],[4].
Another uncertainty is that it is not clear how the cutting of such an old tree was necessary given the topic Currey was studying. Since the Little Ice Age started no more than 600 years ago, many trees could presumably have provided the information he was after for that time period. However, in Currey's original report (Currey, 1965) he refers to the Little Ice Age as encompassing the period from 2000 BC to the present, thus defining the Age over a much longer time period than is currently accepted. Whether this was the common sentiment at the time is not known. In the article, Currey indicates that he sectioned the tree as much from the question of whether the oldest bristlecones were necessarily confined to California's White Mountains (as some dendrochronologists had been claiming) as from its usefulness in regards to studies of the Little Ice Age [5].
Whatever the rationale, the tree was cut and sectioned in August 1964, and several pieces of the sections hauled out to be processed and analyzed, first by Currey, then by others in later years. Sections, or pieces of sections have ended up in various places, some of which are publicly accessible, including: the Great Basin National Park visitor center (Baker, NV), the Ely Convention Center (Ely, NV), the University of Arizona Laboratory of Tree-Ring Research (Tucson, AZ), and the US Forest Service's Institute of Forest Genetics (Placerville, CA), among others.
[edit] Repercussions of the cutting of the tree
It has been argued that the cutting of the tree was an important factor in the move to protect bristlecones in general, and the Wheeler Peak groves in particular [6]. There had been a movement to protect the mountain and contiguous areas in a national park before the tree was cut, and 22 years after the incident the area did gain national park status.
The exact location of the now-oldest tree, Methuselah, is kept secret by the administering agency, the U.S. Forest Service. Because of the importance of the species in dendrochronological research, all bristlecone pines, standing or down, are now protected.
[edit] References
[edit] In print
- Currey, D.R. 1965. An Ancient Bristlecone Pine Stand in Eastern Nevada. Ecology 46(4):564–566 abstract.
- Hitch, Charles J. 1982. Dendrochronology and Serendipity. American Scientist 70(3): 300–305.
- Kelsey, Michael R. 1999. Hiking and Climbing in the Great Basin National Park: A Guide to Nevada's Wheeler Peak, Mt. Moriah and the Snake Range. Kelsey Publishing, Salt Lake City, UT. ISBN 0-9605824-8-7. (This book contains a map showing the approximate location of the tree on Wheeler Peak, as does another of Kelsey's books, Mountains of the World).
- Lambert, Darwin. 1991. Great Basin Drama: The Story of a National Park. Roberts-Rinehart Publishers. ISBN 0-911797-95-5
