Thursday, February 19, 2015

Heron Pond in Winter

     It has long been a dream of mine to visit Heron Pond Nature Preserve in the winter.  However, whenever there is a large snow event in southern Illinois, there is a strong incentive to stay indoors.  But I've always wondered how difficult it would be to get into the swamps of the Cache River wetlands in the winter.  This week I finally got my chance.

     After receiving 8-12 inches of snow in southern Illinois on February 16 in the year of 2015, I made it out to explore Heron Pond.  The minor road leading to the preserve from Belknap road was not plowed at all, but other vehicles had traveled the road and compacted the snow.  I was able to make it up the hill to Max Hutchison's house with relative ease in my all-wheel drive Subaru, but the road beyond this point was untrammeled by vehicle or by human foot.

My car at Max's house and the untouched snow on the road to Heron Pond
     I was surprised by this since I was not able to make it out there until the day after the snowstorm.  I guess I figured others had the same foolish endeavor to walk out to see winter work its magic on Heron Pond.  Clearly the locals and other nature lovers were far more sensible than I.  I parked my vehicle in Max’s driveway, checked in with the Hutchison family, and geared up for the hike through the snow.

     Unfortunately, I did not have my cross country skis or snowshoes with me, because the conditions were perfect for their use.  How amazing would it have been to ski out to see a Cypress swamp!  But instead I was left to lift foot after foot into the deep powder and it seemed like forever just to reach the parking lot.

Bridge over the Cache River and the trailhead
     I walked down the hill and over the bridge.  The Cache River was frozen except the spots just after the rock weirs.  These are structures created to slow down the flow of the river, to reduce stream downcutting in the upper reaches of river and to reduce sediment transfer to the lower reaches of the river. 

Rock weirs on the Cache River
     The snow made it easy to see the movements of animals.  I noticed abundant deer and squirrel tracks, and even some mink or otter activity along the river.  I spotted a red-headed woodpecker, brown thrush, some mallards, and an owl that flew off as I approached the boardwalk.  It was marvelous to see such a prized and highly visited spot in such unadulterated beauty.  The solitude made me think I was in a vast wilderness, yet I was just a couple miles from my car.

My tracks on the boardwalk and the virgin powder on the trails and stepping stones
     Max advised me to not go out on the ice, although he admitted that the best time to explore the swamp was when it was frozen.  Since the boardwalk extends into the swamp, I did not feel the need to walk out on the ice, although it did look plenty thick.  Just as I was leaving, the sun poked through the Cypress trees and I got the shot I was looking for. 

Cypress Swamp at Heron Pond Nature Preserve
     On the way back to my vehicle, I reveled in the fact that the only human tracks in the snow were mine.  This is truly a magical place and I was truly elated to experience it in a whole new element.  Once I returned to Max’s house, I had to stop in and what do you know, of course they insisted I stay for chili and cornbread.  Who could turn down such a request?

Chili and cornbread at the Hutchison's

Friday, February 13, 2015

Marcescence


If you are out in the woods this time of year you may have noticed that while most trees have shed their leaves for the season, there are a few trees that have not. These trees have leaves that turn brown, but do not fall off, and instead dangle in the breeze and stand out among the many tree branches that have lost their leaves for the season.
Trees and shrubs in the Beech family (Fagaceae), the Hazelnut family (Corylaceae), and the Witchhazel family (Hamamelidaceae) retain their leaves in the dormant season through a phenomenon called marcescence. Marcescence means “withering but not falling off” and it refers to plants that retain their leaves through the winter. Normally, plants develop an abscission layer, where the connection to the vascular tissue is cut, and this is what causes flower petals, leaves, and fruits to be released from an individual plant. But plants that exhibit marcescence do not develop an abscission layer. This allows the plant to sequester the nutrients trapped in the leaves, instead of allowing them to fall to the forest floor to decay. It is also thought that marcescence evolved to deter herbivory. This makes sense since marcescence tends to only occur on young trees. Larger trees shed their leaves since herbivores cannot reach them.
Regardless of the reason, marscesence makes it easy to identify young beech trees in the forest, as demonstrated by the photo.

Thursday, February 12, 2015

Winter Tree ID basics


Woody plants for the most part refers to trees and shrubs, and even though woody plants are dormant this time of year, they can still be identified. While most people find winter tree ID to be difficult, there are several characteristics that make it possible.
The first thing to notice is the leaf arrangement along the stem, which can be alternate, opposite, or whorled. “But it’s winter and there are no leaves!” you might exclaim. Well, there are clues you can look at to determine this. The process by which a tree sheds its leaves is termed abscission, which is a word that comes from Latin and means “to cut away.” When a leaf detaches from the branch, a scar remains visible at the point of attachment.
Observe the leaf scars on the twig in the photo. They are arranged in pairs or “opposite” from each other. This makes identification easy because there are not many woody plants that have opposite leaves and you can remember them with this simple mnemonic device: MAD Cap Buck Horse.
“MAD” stands for maple, ash, and dogwood. All species of maples (Acer spp.), ashes (Fraxinus spp.), and dogwoods (Cornus spp.) have opposite leaves, except for the appropriately named alternate-leaved dogwood (Cornus alternifolia). “Cap” stand for Caprifoliaceae, which is the honeysuckle family. All species in this family have opposite leaves and in Illinois the woody species include honeysuckle (Diervilla spp. and Lonicera spp.), elderberry (Sambucus spp.), coralberry (Symphoricarpos spp.), and different species in the genus Viburnum. “Buck” stands for buckeye (Aesculus spp.) and “Horse” stands for Horse Chestnut (Aesculus hippocastanum). There are very few possible exceptions, and most of these only look opposite (but are really whorled). Despite the exceptions, the vast majority of the time a woody plant with opposite leaves will be one of these options. The twig in this photo is Horse Chestnut, a non-native species that has been commonly planted in the US.
Also present in this photo, on the surface of the leaf scars, are bundle scars. This marks the severed connection of the vascular bundles that transport food and water between the twig and the leaf. This species has seven distinct bundle scars arranged in a U-shaped pattern. In fact, the bundle scar is shaped like a horseshoe, which may be where it gets its name.
Other features visible along the twig are dots called lenticels. Lenticels are present on some species and they are small openings that allow for gas exchange between the twig and the atmosphere. Near the left end of the twig in the photo is a group of rings that are called bud scale scars. This indicates the end of the previous season’s growth. You can actually determine the age of young trees by looking at the bud scale scars.
Lastly are the buds. Horse Chestnut has very large and resinous buds. Buds at the end of the branch are called terminal buds and buds that emerge from the side of the twig are called lateral buds. This marks the end of the current season’s growth and is where new twig growth will start from during the next growing season.
Opposite leaves, seven bundle scars, broad leaf scars at least ¼ inch across, with large (up to one inch) sticky buds keys out to Horse Chestnut.
Now that wasn’t that hard was it?