Recently in tree math Category

Well, after a couple of days, the twig I found on the ground and brought in the other day has started to look pretty sad. With the leaves drying out and curling up, I found myself noticing the twig itself more and remembered that I could tell how much a twig had grown each year by looking for the rings or knuckles (they're actually scars from the old terminal bud).



The current growth ends at the tip (the top circle) and goes down to where the green stem ends. That's the first ring on the twig. Going down to the second ring, we can see that last year's growth was just a bit more than the twig managed to grow this year before it was blown off of the tree. The two previous years both look to have been years with smaller growth. And then, four years ago, the growth was much bigger. I recall that when I looked for rings on my twig before, I noticed that the growth from four years ago - 2007 - was like three times a long as the other years. I remember looking up the weather for that year and seeing that it was one of the warmest years on record. Having noticed the same growth pattern on this twig, I thought I'd take a closer look at the temperature that spring. I looked up the high temperatures from April 18th, when I first spotted green tips sprouting from the terminal buds on my tree, through June 9th for 2007 (blue) and 2011 (red). I made a little graph so I could see exactly how much warmer 2007 was than this year.



You can see that there are barely any points where the 2011 graph is above that of 2007. And it looks like it was significantly warmer for a long period in early May of 2007. From watching the development of my tree, I'd guess that that is a key period for early leaf and shoot development. That might account for the difference. But still, 2011 doesn't look too bad actually. I wonder if 2011 could end up being a big growth year after all. Who says these stems are done growing?

I snapped a picture of the twig closest to my living room window so I could compare the new growth this year with the previous year's growth. 



This year's growth ends where the green ends and last year's growth ends at the ring at the bottom of the picture. Judging from the photo, I'd say it hasn't yet grown as much as it did last year. 

Yesterday, I showed you a picture of the cluster of leaves growing at the very tip of the twig closest to my living room window.



This cluster seems to be growing really strong. It doesn't have any other leaves blocking its sunlight and it doesn't seem to mind a few aphids having an occasional snack. Since I noticed last week that the leaves I'd been measuring seemed to stop growing, I decided to start measuring these leaves instead. I chose to watch the development of the newest and smallest pair. My first measurement was done on May 23rd, when the littlest leaf measured 1 1/2".



After some impressive rain storms that night, I awoke the next morning to find that only one half of the leaf pair was still there! Oh no.

Okay, so you know the leaves I've been watching? They've stopped growing. Oh, all the other leaves are growing, just not the two I'm measuring. What up with that?!

Here we go. Middle leaf, May 18th: 2 1/8".

When we last checked in on our leaf, on May 8th, it measured 1 1/2" long. On the 10th, it was just shy of 1 3/4".



On May 12th, it measured just over 1 3/4".



And on May 14th, almost 2".

Last week, I noticed that my tree has compound leaves, which means that each leaf is made up of several leaflets. In fact, I said that each leaf was made up of seven leaflets because the leaves that came out first all seemed to all have 7 (as seen in this picture from May 1st).



So I thought my tree was a 7-tree, making leaves with 7 leaflets. I don't think that anymore. As I've been measuring specific leaves on my tree, I've noticed something. Let's take a look at a picture from May 3rd, when I started measuring leaves.

As we saw yesterday, the leaves on my tree are growing longer, about 1/8" per day. While I was wondering about the growth of the leaves, I was also wondering about the shoots. Are they also getting taller? I mean, the branch is supposed to get longer each year, right? So, can I figure out how much taller it's growing? Let's see...

Since the flowers have fallen off my tree and the leaves have started growing, it just doesn't seem like anything very dramatic is going on out there anymore. It's a little greener; it's a little leafier. But how much greener is the tree each day? How much leafier?

In order to answer this question, I chose a leaf to measure regularly to see how fast it was growing. I looked back at the pictures I'd taken of other leaves and noticed that I'd actually caught a glimpse of this leaf as it started opening on April 29th.



I started measuring the leaf four days later. (Note that this requires a precarious balancing act of me hanging out the window dangling a camera and a measuring tape 15 feet above the sidewalk, so it's a little imprecise. But I think the growth is significant enough for me to get an idea of how fast things are happening.)

We estimated how tall my tree was yesterday, but just how big is all that branchy stuff on top (aka, the crown)?



Hmmm, if I could just pop one of my boys up on the roof of that white truck in front, then I could measure one big boy unit in this picture.



Through the magic of Photoshop, I've moved one boy from the sidewalk to the top of the truck, and it turns out that one big boy unit is pretty much the distance from the top of the truck to the top of the trunk where the branches begin. Result. Now, we pop the boy ruler into the other picture, adjust so he's the right height, and...