Winter can seem a bit drab – especially if you are pining for summer wildflowers. The colors of winter are a bit more subtle, but they are there. And, winter is a good time to look at trees and shrubs from a different perspective. Without the leaves and other plants surrounding them, it’s much easier to notice the differences in the bark, twigs, buds, and general structure of trees and shrubs. We started out walking through Longenecker Gardens, down the main lane marked for cross-country skiers. No competition from any skiers today though, it was just us nature lovers today crunching through a thin mix of ice, snow, frozen leaves and grass. While it was a no-go for skiers, the turkeys were taking advantage of bare patches in the ground that makes it easier for them to find their food. I had packed up some animal track sheets for today, but without any fresh snow most of what was left were the heavier tracks of these turkeys. And, we didn’t have to do much tracking, as we stumbled upon one flock of male turkeys by the crab trees and a flock of females by the evergreens.
Walking somewhat eastward on this main lane through the gardens, we could get a clear look at the shapes of an impressive row of tall, elongated oval maple trees. At the ends and along the twigs of these maples, are deep brownish red winter buds. You can get a good look at the shingle-like layering of the buds’ scales with or without a magnifying glass. These scales are very tough modified leaves. They have evolved to encase and protect next years’ leaves or flowers, or a mix of leaves and flowers through the winter dormancy period. On the maple tree, and many others, the floral buds are larger and rounder than the leaf buds. All these maple buds appeared fairly short and stubby compared to the sharp long needlelike buds of the beech trees. At first we may not see these beech buds, and mistake them as an extension of the twig, or for thorns on the tree. Perhaps, this is an intentional disguise. Many animals, especially squirrels are on the prowl for buds as an item on their winter food menu. For the tree, loosing these buds means loosing some of their soldiers in the crucial timing of spring flowering and leaf-out. If buds are lacking a good disguise, or don’t have some nearby source of tree seeds or nuts for winter animal feed, some buds will employ a bitter tasting resin to discourage hungry animals. For us store-fed humans merely hunting for some intriguing winter wonders, magnolia buds are a popular item. You can notice that the outer parts of these buds are the soft large leaves that we will come out to photograph in spring. They seem very vulnerable – mainly relying on dense soft hair for protection. You can find the magnolia trees in the southwest corner of Longenecker Gardens or by the fencing of the gardens across from the Wingra Woods parking lot.
Our trees are in dormant stage – while all activity is slowed dramatically, there is something very special happening. These buds develop, swell, and open because they have evolved much further beyond our awareness or know how of the seasons – they hold the secrets of knowing when the fall will give way to winter and eventually bloom into spring. Hormonal and chemical changes occur in the fall, mainly stimulated by changes in day length, but also by temperature, and diminishing availability of water and nutrients from the soil that led to the growth of these buds. But, that’s not their only, or their most important magical trick.
How does a tree know when it is safe to break this dormancy period and spread out its leaves and flowers? A mistake here could be very costly. There are mistakes – like the cherry and fruit trees in Door County recently breaking dormancy and then getting hit with a spring freeze that destroyed a good deal of their flowers. I think that was more of a mishap of an unusually late frosty day in spring rather than an early errant break in dormancy however. In the grand scheme of time, these tree creatures don’t seem to be making many mistakes. Researchers think that their secret to success may be bringing into account a multi-factorial confluence of factors before the chemicals and hormones will release their hold and signal the opening of these tree buds. They do react to the warming soil and air temperatures, the increase in moisture and soil nutrients, and take special notice of the increasing day length. Researchers have devised experiments to try and trick tree buds out of dormancy by artificially increasing light, temperature and soil conditions – and it didn’t work. The trees noticed that winter was missing. Just like some seeds need a certain period of cold weather or winter conditions, the tree starts doing its spring thing only if its really convinced that winter has occurred – and these trees are in essence “counting” the winter days to calculate along with the other factors in discerning that it is truly the end of winter. An essential part of their strategy in the health and survival of their species.
So, that’s a lesson for us – lots of elegant and complex things going on right under our noses and eyes as we look at these interesting buds. I have read some about the various chemicals and hormones that are being studied in relation to dormancy. I think I could sneak by making the best of trying to pronounce them all, but it’s still beyond my knowledge and vocabulary, and many words may be beyond my spell check. Possibly, I’ll pick out a choice few chemicals for another winter walk.
We usually don’t see many insects in winter. But, we can often find evidence of their activities. A common site is the abandoned nest of the bald-faced hornet. You can find them throughout the Arboretum and around town. One of the more visible ones was in a Katsura tree just 25 yards or so in from the stone entrance to Longenecker Gardens off the main parking lot. Their nest usually appears as a small gray football sized and shaped aerial nest attached to trees and buildings. The nest is a many-tiered covered nursery. Throughout the summer, there may be around three hundred or more larvae that will be fed and hatched from these nests.
The bald-faced hornet is in the genus with the common name yellow jacket. It is actually not a hornet, and does not have any yellow coloration. These are two good reasons why we like to provide you with the scientific/ binomial/ Latin name for plant, animal, and other creatures. The insect that made this handsome nest is a wasp, and its scientific name is Dolichovespula maculata. The genus name, Dolichovespula, means long or narrow wasp. Maculata means spotted. Which it is not really – more like banded. They are dark black with patterns of bright white bands on their head, thorax and abdomen. I showed a photo and proposed replacing the confounding bald-faced hornet moniker with a much more accurate common name: “piano-faced wasp” (you heard it here first).
Males have an additional white band on the first abdominal segment as well as at the tip. Workers measure between 12 and 15mm (about ½ inch) while the queen is substantially larger at 18 to 20mm (about ¾ inch). We did not see one today, but there are queens somewhere nearby – perhaps burrowed in the crevice of fallen tree or buried in some brush. As the days grow sufficiently warm, the queens will become active and search around for flaking strips of wood, chew it up and use the partially digested slurry to fashion the nest for the next year’s brood.
Many people are afraid of hornets, and they can sting. However, these insects actually hunt and eat flies, moths, and other insects keeping the ecosystem balanced. Once in a while they will also feed on the nectar of flowers. Most of the time however, they prey on bugs that eat our garden plants and vegetables, spread germs, and bother us. And since their nests are usually up in a tree well above our heads, chances are you won’t be disturbing their nest – which is the surest way to get stung.
I read an excerpt from Allen Young’s book entitled, Small Creatures and Ordinary Places: Essays on Nature. “Paper wasps, at base, are the recycled tissues of caterpillars. Caterpillars are largely grazers on living plant tissues. When we think of a carnivore, typically a large animal comes to mind, such as a wolf or mountain lion. But the reality is that most carnivores are arthropods – centipedes, spiders, and many other kinds of insects. This fact alone says a lot about the manner in which the rich diversity of plant-grazing insects – by far this planet’s largest slice of animal life, is kept in some semblance of balance.”
Another book I like to re-read every winter is by Bernd Heinrich. It’s entitled, Winter World: the Ingenuity of Animal Survival. Ingenuity is a great word for the theme we touched on most today – both of plants and animals that adapt and survive. We did not get much time to delve into the survival and strategies of birds through the wintertime, but they got an honorable mention as we walked into Wingra Woods and heard but didn’t see a downy woodpecker, red-bellied woodpecker, and a few nuthatches. We did see some reliably active and chatty black-capped chickadees.