The project, fittingly called trees, attached sensitive microphones to trunks, branches and even leaves, then recorded the sounds and analyzed them in light of simultaneous environmental factors such as drought. Click here to hear the clicks, pops, hisses and taps made by a Scots pine (Pinus sylvestris).
Closer to home our trees are getting ready for spring, the sap is running, and it’s maple sugaring time in North America.
And so I wonder …
If we had those special microphones could we heard the sap rising in the maples?
In 2010 Alex Metcalfe installed headphones on a copper beech at Oakville Galleries in Oakville, Ontario. Anyone could listen to the tree using his installation — and so can you with this video. Wow!
(photos from Wikimedia Commons. Click on the images to see the originals)
These very different leaves came from the same tree.
Sassafras turns red and yellow in the fall showing off its unlobed leaves, two-lobed “mittens” and three-lobed “paws.” All three shapes grow on the same tree including both right and left-handed mittens (I checked).
Sassafras (Sassafras albidum) is a medium-sized tree native to eastern North America from southern Maine to Florida to eastern Texas. In Pennsylvania it grows everywhere except on the central high plateau of the Northern Tier.
The tree’s roots, bark, shoots and fruit were used directly in many foods, drinks, perfumes and medicines (think “root beer”) until the essential oil, safrole, was discovered to be carcinogenic and outlawed by the FDA in 1960. Sassafras by-products can still be used in food and cosmetics as long as they’re certified safrole-free. Safrole is used in pesticides.
In Europe people plant sassafras as an ornamental for its aromatic scent and unusual leaves.
Here’s something I literally stumbled on in Schenley Park: shagbark hickory nuts (Carya ovata).
The big round balls, which cradle easily in the palm of my hand, are husk-covered nuts. They’re green when ripe but turn brown with age (bottom right). Their four sections naturally come open as the nut ages and sometimes burst when they hit the ground.
I didn’t need any special tools to open the husks, just my fingers. At first I didn’t realize they were merely husks so I thought it was odd that they didn’t protect the nut but…
The nutshell is another story (center of the photo). Irregularly shaped and slightly larger than a quarter, I tried to open it by cutting and other gentle means but it was impossible. The meat inside is reputed to be sweet but I had to destroy the nut to taste it.
Hmmm. Get out a hammer or hire a squirrel.
I got out the hammer.
The first nut had very shriveled meat inside. Perhaps it had been attacked by a bug.
The second and third nuts looked promising except that the meats resembled dried Chinese wood ear mushrooms and they tasted like nothing. (My photo doesn’t do this justice.)
Either I was doing something wrong — quite possible — or these nuts are not as good as described.
I wonder how many nuts the squirrels spend time opening only to find that the meat inside was not worth it.
Though we (usually*) don’t eat them, acorns are a key link in the woodland food web. They’re so popular that oaks have evolved an abundance-scarcity strategy to throw off their consumers. In some years acorns are so abundant that the crop overwhelms the acorn-eaters. In other years they’re so scarce the consumers go hungry. To further confuse things the oak groups cycle on different schedules: white oaks have a bumper crop in 4-10 years, red oaks on a 3-4 year basis.
Who eats these acorns? Squirrels and chipmunks are the obvious consumers but plenty of other species depend on them including white-footed and deer mice, blue jays, red-headed woodpeckers and wild turkeys. Deer, ruffed grouse, bears, mallards and wood ducks eat acorns, too.
The population of white-footed and deer mice increases in the year after a bumper crop of acorns.
Rodents attract predators so the raptor population increases.
Too many rodents and raptors causes junco nest failure due to predation on eggs, nestlings and birds.
Mice eat gypsy moths so the gypsy moth population drops.
The number of ticks increases as white-footed mice and deer increase.
And then, this information from PLOS links acorns to Lyme disease: Lyme disease increases predictably two years after an acorn bumper crop because white-footed mice are a main reservoir for the Borrelia burgdorferi bacteria.
Don’t blame the acorns.
Everything is connected to everything else.
(photo from Wikimedia Commons. Click on the image to see the original)
*p.s. Is this a bumper crop year? I wrote about acorns because I’ve been dodging them in Schenley Park as they fall, but not all the trees are prolific. Hmm….
*”We don’t usually eat acorns”: Well, we can if we put a lot of work into it. See kc’s comment!