After enough time spent paying attention to a tree species, you tend to come up with a bit of data even if you’re not really trying to.
This Joshua tree is at Keys View in Joshua Tree National Park, right around the southern limits of the species’ range. The shot on the left was taken in February 2000, the shot on the right about three weeks ago. That’s a decade of growth.
I see a few interesting things that have happened to this tree in that time, though it would be easier to compare the two if I’d managed to get them both taken from the same vantage point.
At A, in 2000, a bud had sprouted atop the stub of a previous limb and formed a rosette. By 2009 that leftmost rosette had about doubled its height, which still isn’t very much growth. Note the clump of dead leaves around its base. Note also that the healthy leaves beneath that rosette, on the underside of the limb, have died back. It’s a little hard to tell from the 2009 shot, but that lower rosette has flowered and died back, and it looks as if there’s a new sprouted rosette growing on the left side of the dead leaves.
At B in 2000, the top shoot had just flowered the year before, which we know because the leaves on that rosette are still green. Ten years later that rosette has died, and three new rosettes are visible growing on the opposite side of the trunk.
At C the three obvious rosettes growing in mid-trunk have developed a bit more stem, and if this tree survives the next couple human lifetimes it may eventually have a less asymmetrical canopy, as those new stems fill in the empty space above them on the right side of the tree.
Overall impression, this tree is growing sloooowly. At the limits of its range, it is exposed to more heat and drought than it likely would prefer.
Take a look at other parts of the tree. What else has changed in the last decade? What hasn’t changed on the tree? Why might that be? You don’t need to be an expert to venture a guess.
Oh, and my wildly inaccurate handwavy guess is that based on the rate of growth in the last ten years, this tree is somewhere between 100 and 120 years old. Assuming conditions and rate of growth have remained constant etc.
hey, cool
I’ve got lots of 20-year-old slides of various JTs…
Neat!
Don and I used to have a few favourite hikes in eastern Ontario. Several years ago, I began picking a spot to shoot photos from, especially places where water levels on creeks could be photographed - and I would shoot from that spot each time we hiked by. I tried to be very accurate in standing in exactly the same spot each time. It made for some interesting comparisons. I’ve often thought it would be a useful way for naturalists to collect information on various sites over a long period of time.
The trunk might be thicker, it seems to be leaning more. Although larger, it looks drier, but that could just be the season, perhaps.
May well be leaning more, SF, but I’d hesitate to judge without framing the shot more like the first photo.