This edition of the Longest-living Organisms concerns the longest-living conifer, the bristlecone pine. Bristlecone pines are a small group of pine trees, one species of which, the Great Basin bristlecone pine, lives longer than any other type of tree. They occur only in high altitudes in the Western United States. The trees grow very slowly due to cold temperatures, dry soils, high winds and short growing seasons. The areas they grow in rarely harbour diseases that harm them. Their wood is very dense and resinous, and thus resistant to invasion by insects, fungi and other potential pests. They range from approximately 5 to 18.5 metres tall. By measuring the rings in wood from the older bristlecone pines, scientists can determine what the climate was like thousands of years ago.
The oldest documented living tree is a Great Basin bristlecone pine in the White Mountains of eastern California. It is more than 4,700 years old. A collection of bristlecone pines on Wheeler Peak in eastern Nevada is known to contain several trees over 3,000 years old, with one thought to be about 5,000 years old.
Sources:
"bristlecone pine." Encyclopædia Britannica. Encyclopædia Britannica Online School Edition. Encyclopædia Britannica, 2010. Web. 23 Sept. 2010 <http://school.eb.com.au/eb/article-9016487>.
Sprugel, Douglas G. "Bristlecone pine." World Book Student. World Book, 2010. Web. 23 Sept. 2010.
http://en.wikipedia.org/wiki/Bristlecone_pine
