Size Factors

• Size is not a terribly good indicator of age in trees. There are many factors that affect a pine's dimensions. A Jeffrey pine growing on nutrient-poor serpentine soil in the Klamath Mountains of the Pacific Northwest may be stunted and slender even when a century old, whereas a younger individual on richer soil at mid-elevation in the Sierra Nevada may be much larger. A timberline species like a bristlecone or whitebark pine may show a krummholz, or "crooked-wood," form at great age due to the harsh conditions. Pines growing too close to one another may limit each other's resources and mature smaller than specimens in an open woodland or savanna. In other words, factors of soil, climate, topography and stand can influence size more significantly than mere age.
  
  

Age and Size

• Like humans and many other organisms, pines don't necessarily grow significantly throughout their entire lives. Often the trees cease increasing in height after a certain point: say, after around 160 years for ponderosa pines in certain sites, for example, or after roughly a century in longleaf pines. Such trees may continue to add to their girth, however. The volume of eastern white pines, one of the biggest trees in the East, continues to increase slowly at 100 years of age. Sugar pines, largest of the world's pines, grow slowly initially but then accelerate, and may continue to increase in size for some time: A 100-year-old sugar pine may still be growing by 2.5 percent or more in basal area, according to Kinloch, Jr. and Scheuner in their entry on the species in the 1990 Forest Service manual "Silvics of North America."
  
  

Examples

• A 100-year-old longleaf pine -- one of the dominant species of the American Southeast, historically covering thousands of acres in grassy savanna -- may be 120 feet tall and three feet across in the trunk. Century-old eastern white pines in a North Carolina plantation stood on average 112 feet in height.
  
  

Maximum Ages

• Pine trees tend to be relatively long-lived. Indeed, they include in their number the single organism with the greatest known lifespan: the Great Basin bristlecone pine, a high-country species of the American Southwest that may live 4,000 or 5,000 years in timberline groves at 10,000 feet of elevation or more. Even after death, the contorted bristlecone snags continue to impress -- and may stand for many thousands of years more, thanks to the natural preservatives of a cold, dry microclimate. Ponderosa pines can live 900 or 1,000 years; sugar pines and eastern white pines may exceed 500 years old.