Posts Tagged ‘Things That Fall From the Trees’

I didn’t realize, until I started cleaning it up, how much stuff falls from trees. There must be tons of it raining down; it falls 24 hours per day seven days per week. Eastern forest broadleaf trees alone, it is estimated, can drop 2 to 3 tons of leaves per acre in the fall. And then there are the branches, seed cones, acorns and everything else that falls. If it wasn’t for the animals, bacteria and fungi that process it we would surely be buried under it all.

The tiny black specks you see here are seeds of the gray birch (Betula populifolia). Tiny yes, but there must have been millions of them in this small birch grove. Pine siskins, chickadees, and other songbirds eat them. Deer, moose and rabbits eat gray birch twigs.

I thought the brown on the snow in this shot must be dust like seeds but I suspect it was just dust.

Eastern white pines (Pinus strobus) drop an incredible amount of material each year; large branches, needles, cones and bark all end up on the forest floor.

Whenever I see a fallen pine branch I check it for lichens and probably 8 out of 10 times there are lichens on it. I believe this foliose example is in the Tuckermanopsis family, possibly Tuckermanopsis americana. It was quite dry even though it was on the snow, so I’d guess that its color had lightened.

After branches pine cones are probably the things that fall out of pine trees the most. They are everywhere, but they don’t always fall end first into the snow like this one had. The heavy end falls first sometimes like this one did but I’ve also seen them turned 180 degrees with the lighter end in the snow.

Usually when you see a fallen pine cone they look like this, but this one has done something special; the sun had heated it enough for it to melt its way into the snow. I’ve seen oak leaves melt into the snow in the same way.

When I see good size fallen pine limbs I always look for bark beetle damage. Bark beetles usually attack weak or dying trees but they can also kill healthy trees by girdling them.  Adults bore small holes in the bark and lay eggs in a cavity. Once the larvae emerge from the eggs they make tunnels in the inner bark, like those seen here. Once they stop feeding they will pupate at the end of these tunnels. The pupae then become young adults and fly off to find another tree. These beetles carry spores of various fungi which can grow on the outer sapwood and stop the upward flow of water to the crown. Bark Beetles include over 100 species and it is said that their work is like a fingerprint for the species. They can create such beautiful patterns in wood that it looks as if a calligrapher has taken up a chisel instead of a pen.

Mosses of course, are also common on fallen branches. These were very dry but the shield lichen next to them didn’t look too bad. I think it was a common greenshield (Flavoparmelia caperata) , which is indeed very common. They often have patches of granular soredia on them as this one did in its center.

If white pine branches are the most common on the forest floor then eastern hemlock (Tsuga canadensis) branches are the second most common. The difference about hemlock branches though, is how they are almost always small enough to decompose quickly.

Both pines and hemlocks catch much of the snow on their branches, and underneath them the ground is often bare or nearly so in all but the snowiest winters. These bare spots are often full of small birds like juncos scratching around for seeds.

Honey locust (Gleditsia triacanthos) seed pods are pretty things. When the seed pods are green the pulp on the inside is edible and very sweet, while the pulp of the very similar black locust (Robinia pseudoacacia) is toxic. One good way to tell the two trees apart is by the length of their seed pods; honey locust pods are much longer and may reach a foot in length, while black locust pods only grow to about 4-5 inches long. Honey locust seed pods look a lot like giant flat string beans about 9-12 inches long and often curled. Some of them look like polished mahogany and others can be purple. Beautiful white, fragrant flowers cover these trees in late spring. Locusts are legumes, in the pea family. Deer love the seed pods, which often fall in such abundance they cover the ground under the trees.

You want to watch where you walk under a honey locust because fallen branches can be very thorny. Honey locust thorns grow singly and can be 3 to 6 inches long. They will sometimes branch like the example in the photo. These thorns are big and as hard as iron. They can reach 6 inches in length and poke right out of the bark of the tree along its branches and sometimes even the main trunk. They are tough enough to puncture shoe soles and can cause a nasty wound. In the past the hard thorns of the younger trees were used as nails. Confederate soldiers once used them to pin their uniforms together and survivalists still use them as fish hooks, spear heads, nails, sewing needles and even small game traps. Native Americans used the wood to make bows, and medicines were made from various parts of the plant.

The orangey color of these leaves caught my eye. I think they may have been American hornbeam leaves (Carpinus caroliniana). This tree is also know n as muscle wood, ironwood, hornbeam and blue beech, and younger trees will often hang onto their leaves quite late into the year.

In the fall shortening day length tells most deciduous trees that it’s time to stop growing, so the tree forms a layer of waxy, corky cells at the base of each leaf. This is called an abscission layer, and it slows and finally stops the flow of sap to the leaf. In some trees like oak (Quercus), beech (Fagus), and hornbeam (Carpinus), this abscission layer forms much later, so even though the leaves might freeze dead and turn completely brown they still cling to the branches. Pin oaks (Quercus palustris) don’t form an abscission layer until spring, so their leaves stay on the tree all winter. This retention of dead leaves is known as marcescence. When I start seeing lots of beech leaves blowing around in late winter I get excited, because that means spring isn’t far off.

I think this pile of beech leaves, blown by the wind, was fairly recent.

I see a lot of woodchips around dead and dying trees, almost always left there by woodpeckers. These small bits of wood disappear quickly.

Trees losing their bark isn’t anything strange but there were a lot of animal tracks around this tree and it looked like an animal might have pulled this piece of bark off. Porcupine maybe?

This white pine had lost some of its bark but it wasn’t lying on the ground anywhere near the tree that I could see. Wounds like this are how fungi can get into a tree and start things like heart rot.

I was surprised to see a virgin’s bower vine (Clematis virginiana) on the ground. This vine can climb high enough to make it into the trees occasionally but usually it just drapes itself over shrubs and hangs on tight. It’s more likely to decompose right there on the shrub than to fall on the forest floor. Those long feathery filaments called styles are on its seeds (fruits) so the wind can carry them, but that can’t happen if they’re on the ground.

This switch grass did most certainly not fall from a tree but its delicate beauty caught my eye so I’ve put it here. I hope you enjoy seeing it as much as I did.

Anyone who thinks fallen leaves are dead has never watched them dancing on a windy day. ~Shira Tamir

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If you’ve spent much time in the woods you know that there is an incredible amount of stuff falling from the trees. What is it? It is made up of everything from the lichens and mosses that perch on the trunks and branches to the trunks and branches themselves. Where does it all go? Thankfully the decomposers clean all of it up. If it weren’t for them we’d be up to our noses in forest litter. Bears, woodpeckers and other animals shred larger logs into smaller pieces and then the termites and ants make the pieces even smaller. Bacteria, slugs, snails, worms, centipedes, microbes and many insects all have their shot at cleaning up the forest and then there are the fungi and slime molds. Between them all they can clean up a forest floor in a surprisingly short time, but since there is always more falling, their work is never done and their menu never exhausted.

This is a common sight in this region. These little scales are what’s left of a white pine (Pinus strobus) cone after a squirrel has eaten all the seeds from it. Each scale has two reddish-brown winged seeds and they’re a favorite of gray squirrels. Pine cones can close their scales to protect the seeds from the cold and animals but squirrels have figured that out. Native Americans also ate these seeds, which are said to be sweet and nutritious.

The amount of cones a tree will produce varies from year to year but every now and then we’ll have a mast year and what seems like billions of cones will fall. That happened a couple of years ago and the squirrel population seemed to explode. I’ve read that cone production peaks every 3 to 5 years but it seems longer than that. In any event, thanks to the squirrels pine cones disappear quickly.

White pine needles are 3 to 5 inches long, bluish green on top and whitish underneath and grow in bundles of 5. They are pointed, soft and flexible and the tree sheds them every 2 years. In the fall they’ll turn brown and fall off but this doesn’t hurt the tree like some people fear. A mature white pine can be 250 or more years old and each one drops an incredible amount of material each year. There is nothing better to build a camp fire with than fallen white pine limbs. A fire built with them will be hot and will burn down quickly. They are also the tallest trees in eastern North America; the tallest trees living are just under 200 feet tall.

I’m guessing that this piece of wood was hacked out of a tree by a pileated woodpecker. I’ve seen these birds cut standing, rotten trees right in half and have seen large piles of wood chips many times at the base of various trees.

This wood was soft and rotted, and I think fungi had been having their way with the tree it came from. Of course if woodpeckers were after it the tree was also full of insects. I’ve cut down trees and found them full of carpenter ants, which make tunnels all through the tree like termites.

I must see hundreds of fallen branches each week but I don’t see many from the poplar family like this one. Poplar trees (Populus) are in the willow family and their opening buds remind me of giant spring pussy willows. North American poplars are divided into three main groups: the cottonwoods, the aspens, and the balsam poplars. If the buds aren’t sticky then the tree belongs in the aspen group. These weren’t. Aspen buds begin to swell during the first warm period in spring, when minimum temperatures are still below freezing. Air temperature rather than day length determines when their buds will break, so it can vary from year to year.

The flat seed pods of black locust (Robinia pseudoacacia) are a common sight in winter. These dark brown pods stay attached to the tree and their color lightens during the winter. Finally as spring nears they begin to fall and, though they are light and can be blown long distances, many can be found under the tree on top of the snow, as this photo shows.

The tiny brown seeds of a black locust look like miniature beans and that’s because they are in the same family. Their coating is very tough and they can remain viable for many years. They’re also very toxic and should never be eaten.

Eastern or Canada hemlocks (Tsuga canadensis) are messy trees that shed their smaller branches, needles, and cones all winter long but they provide plenty of seeds for the smaller birds like black capped chickadees. The 1/2 inch long eastern hemlock cones are among the smallest of all the trees in the pine family but the trees usually produce so many of them that the ground is completely covered in the spring. The needles and twigs of hemlocks are ground and distilled and the oil is used in ointments, so the next time an ointment helps your sore muscles, thank a hemlock.

The white stripes on the undersides of the flat hemlock needles come from four rows of breathing pores (stomata) which are far too small to be seen without extreme magnification. The stripes make the tree very easy to identify. They look like racing stripes.

Arbor vitae (Thuja occidentalis) is another messy evergreen that sheds small branches by the cartload some years but they provide great cover for birds and I usually have at least one family of robins living in the ones in my yard.

The tiny leaves of arborvitae are flat and scale like. Arborvitaes are in the cedar family and are used extensively in commercial landscaping. The Native American Ojibwe tribe thought the trees were sacred because of their many uses, and maybe they were. They showed 16th century French explorer Jacques Cartier how to cure scurvy with its leaves and bark, and he was so impressed that he named it Arborvitae, which is Latin for Tree of Life. He had trees with him when he returned to Europe, and that’s how Thuja occidentalis became the first North American tree to be introduced there.

The stiff, woody seed pods of arborvitae look like tiny carved wooden flowers. robins, common redpolls, pine siskins, and dark-eyed juncos eat the seeds. Many small birds use the trees to hide in.

Sometimes what falls out of the trees onto the snow is more snow, and sometimes it falls by the bucket load. All of the holes you see here were made by falling snow.

Of course leaves fall from trees but some trees like oak, hang onto many of theirs throughout winter. In the fall shortening day length tells most deciduous trees that it’s time to stop growing, so the tree forms a layer of waxy, corky cells at the base of each leaf. This is called an abscission layer, and it slows and finally stops the flow of sap to the leaf. Once the sap stops flowing to the leaves they lose chlorophyll and the reds, yellows and oranges that the green chlorophyll was hiding finally become visible.

In some trees like oak (Quercus), beech (Fagus), and hornbeam (Carpinus) , this abscission layer forms much later, so even though the leaves might freeze dead and turn completely brown they still cling to the branches. Pin oaks (Quercus palustris) don’t form an abscission layer until spring, so their leaves stay on the tree all winter. This retention of dead leaves is known as marcescence.

Beech is another hanger on. What oak and beech leaves tell me is when spring is near. When I see them falling in large numbers in March I know that the new buds are taking up sap and swelling. Nobody really seems to know for certain why trees retain dead leaves but some believe that one reason might be to ward off foraging moose, deer and other animals. Animals will eat the bud bearing twigs from the lower parts of older trees and from nearly all parts of younger trees. One theory says that they don’t like the taste or texture of the dead leaves so they stay away from the trees, which means the buds stay safe and can grow on.

It’s very common to be walking through the woods and find twigs and branches with large, leafy (Foliose) lichens like the one pictured growing on them. These lichens can be difficult to identify because they change color drastically when they dry out. I think this one is in the Tuckermannopsis group, but I can’t pin down the species.  They’re very pretty and easy to see and I often find them on birch and white pine branches. This family of lichens is probably the one I see having fallen from trees more than any other.

The second most common lichen I see falling from trees is the beard lichen. Though this example was small they can get quite large. Bristly beard lichen (Usnea hirta) like this one is often found on the ground after a wind or rain storm. Many lichens like sunlight and grow in the tops of trees where there is less shade from the leaves. Native Americans used lichens medicinally for thousands of years and lichens in the Usnea group were described in the first Chinese herbal, written about 500 AD. Today scientists estimate that about 50% of all lichen species have antibiotic properties.

We keep seeing things all our life, yet seldom do we notice them. ~Avijeet Das

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