Learning about the rhythm of the trees

Previously we looked at the under-ripened nuts of the Yellow Buckeye. Such a nut probably is not going to be of much value to any animals. But what about the ripened nuts?


A "cracked" buckeye nut outside of a known chipmunk hole.




Chewed apart buckeye husk


A different nut from the one above, but in a similarly destroyed state.

Obviously someone (presumably a chipmunk) was able make use of these mature nuts, but how on earth did they manage to get into the nuts? One thing's for sure: I don't want that critter biting me anytime soon - yikes! And how did the chipmunk go about extracting the meat from the nut? I can imagine what it must have looked like to see a chipmunk with his arm stuck in that nut, trying to get the meat out (can you picture it?).

This chipmunk was lucky that he got any nut meat at all, though. My reason for saying this is because there is a conspicuous lack of nuts in our yard this year. We have quite a few nut-bearing trees on our property, like Black Walnut, Yellow Buckeye, Shagbark Hickory, and several species of oak. Last year was a very "nutty" year, with an over-abundance of Black Walnuts painting our driveway and the Shagbark Hickories providing us with some tasty snacks (see my post about it here).

But it's not just our trees. There seems to be a consensus that this is definitely a dry year far as the nuts are concerned in this corner of southeast Ohio. I've heard similar reports from one friend who lives in a different area of the county and from another friend in a neighboring county. Interestingly, I just read a post over on Leedra's blog (she's in Tennessee) about how one of her trees (a chestnut of some sort, we think) has branches that are breaking because they are so weighed down with nuts.

So what's up with the lackluster nut production this year? Of course, my curiosity leads me to do dangerous things, like researching such mysterious subjects on the internets (and learning to plug in the right combination of words on Google until I find what I'm looking for). The answer to what is going on is all about the masting cycle of the trees.

I've heard of the term "masting" before, but I didn't really realize the scope of it until now. A mast year is "a phenomenon when the fruit (mast) produced by trees in a given year is exponentially higher than the average" (from dictionary.com). Apparently other fruit-bearing plants (not just trees) experience this phenomena as well. From the reading I have done, masting in plants is not a process that is well-understood, but there are quite a few hypotheses. One of these hypotheses is that during a mast year, so many nuts fall that any nut-eating predators will easily have their fill, and thus leave behind plenty of nuts to be propagated in subsequent years. (This hypothesis is called "predator satiation".) Another proposed hypothesis is that the creation of flowers (and thus fruit) is a very energy-intensive process, and that the trees need time to "recharge" after a period of such prodigious production. Most of a tree's energy during a non-mast year is spent on growth, whereas less time is devoted to growth during a mast year.

Masting is a cyclical occurrence, and while there is likely no hard and fast rule for how often a mast year will come along, reports that I have read indicate that anywhere between 3 and 7 years will pass between mast years. What happens during those in-between years is... well, not much as far as fruit/nut production goes. It seems like an all-or-nothing type of situation. Of course it's not really "nothing," but it could definitely be characterized as "very little." Last year, due to the over-abundance of nuts in our woods, we had very little problem with squirrels at the bird feeders. This year is a completely different story: it is now common to see 5 or 6 gray squirrels at the feeders at once, and the flying squirrels have seen their numbers go as high as 8 10 at a time recently. The chipmunks have also started visiting our feeders, which is a first according to my observations.





Cheek pouches stuffed to the max!

Another aspect of the masting process is called "synchrony." This is when a group of trees over a large area coordinate to mast in the same year. This explains why my friends who live within a 30-mile radius from me are seeing similar patterns in their trees. I would expect those who live in eastern Tennessee, like Leedra, to see lots of nuts this year. It is unknown how this synchrony is achieved, although some think climate conditions might be a contributing factor. Amazing, isn't it?

So I have to ask you, all my blogging friends who are spread far and wide, what trends in tree nut production are YOU observing in your neck of the woods? I would LOVE to hear about it!