March 20th, 2009
Oaks grow slowly. Here are two comparisons of the growth of two oak trees:
The images cover a 35 year period and range from black and white to high-resolution digital. This oak appears to change shape with the years, but that’s just the effect of the shadow from being taken at different times of the day. If you mentally remove the shadow, you’ll see that the oak remains fairly circular. These images have all been scaled to be directly comparable, so you can see that the tree itself has grown very little in 35 years; I measured the tree’s image size as 44h x 47v in 1966, and 52h x 56v in 2001 -- not much growth. Here’s what this tree looks like from the ground:
Here’s another set of trees from the air:
And here’s what they look like from the side:
The oak tree on the right, looking rather scrawny without its leaves, is the dominant tree in the aerial photos. The oak tree on the left edge, also rather scrawny-looking, is the tree in the lower left of the aerial photos. The madrone tree dead center doesn’t appear in the photos and is actually quite young. The two Ponderosa Pines that are the tallest trees in the picture don’t even appear until 1980; in 1985, they’re still small and even in 2001 they don’t look that big. This is because Ponderosa Pines are tall and narrow, while oak trees are short and broad.
At the extreme right of the ground-level photo you can just see two Ponderosa Pines. They show up at the right edge of the aerial photos as well. All four of the pines in this photo are about 30 years old; they are between 20 and 24 inches in diameter, implying an average growth rate of roughly 3/4” per year -- that’s a healthy growth rate. An inch a year is great; half an inch a year is a bit weak. They’ll start slowing down soon; once pine trees get above 30 inches in diameter, they slow down.