Growth of Southern Yellow Pine

[Amelia Farms]

I am trying to learn a bit more about the growth pattern of SYP. I have quite a few on my property of varying age and size. I have a few real monsters, about 24" DBH and probably 80' tall. I have quite a few more that are nearly as tall as the large diameter trees, but only about half the diameter or less. Will these smaller diameter trees ever get much larger in diameter? I assume they have pretty much maxed out on height. All these are in mixed pine/hardwood areas, there are some huge oaks mixed in as well.

[ncsuclell]

I believe they will get larger as long as they stay alive.  If you know someone with an increment borer you can estimate the growth rate from the rings.

[WDH]

The smaller trees of the same height as the larger trees will not get a whole lot bigger unless they have room to grow.  If they are crowded in by other trees and hardwoods, the growth will be slow.  If some of the competing trees are removed (thinned out), they will grow faster.

Growth is also dependent on age, just like in people.  Once SYP reaches about 30 years old, the growth slows down to less than half of what the trees grew when they were teenagers.  That is just a fact of life. 

Take some pictures of the subject trees and the growing conditions, and we can better assess their growth potential.

[Amelia Farms]

Thanks for the replies fellas. I will try to get some pics this weekend to show what I am talking about.

[Phorester]

From your description it sounds like ordinary forest growth.  Trees of the same height will be roughly the same age.  Diameter is more of an influence of growing space, not age.  The larger diameter trees were simply able to out-compete the smaller ones.