Signs of Fall in the Blue Ridge
Seasonal changes in flowering are well known but the specific reasons for spring/summer/fall timing are not always so clear. For example, the famous witch hazel is now blooming in the woods and it is one of the few woodland trees to do so this time of year.
Witch hazel flower
Seasonal changes in flowering are well known but the specific reasons for spring/summer/fall timing are not always so clear. For example, the famous witch hazel is now blooming in the woods and it is one of the few woodland trees to do so this time of year. One obvious idea is that flowers in fall will have far fewer competitors for pollinators. But on the other hand, there will be fewer insects available for pollination. The strange one-year-old fruits are also visible.
Similarly, some asters such as this white wood aster are in full bloom in September. I noticed some bumblebees visiting the flowers; they are warm-blooded and designed for flying in cooler conditions. Another common late summer and fall bloomer along roads and paths is white snakeroot, which has here attracted a flower beetle. We sometimes forget that beetles can pollinate flowers and indeed were present earlier in evolutionary history than the later evolving bees and butterflies.
White woods aster
Flower beetle on white snakeroot flowers
While walking in the yard, our son noticed a very interesting fungus, the elegant stinkhorn or devil's dipstick. The phallic shape of this peculiar fruiting body has elicited some strange human reactions. It stinks in order to attract flies that pick up the spores and distribute them widely.
Some amazing life and death scenarios can be observed in flowers- note that in this morning glory flower a bumblebee is foraging deep in the flower, but a crab spider has caught a Zabulon skipper and is eating it.
Elegant stinkhorn
Skipper male Zabulon caught by crab spider in morning glory with bumblebee
Red eft
Occasionally on a damp day, you may be fortunate to observe one of the most beautiful salamanders in our woods- the red eft. It is an immature terrestrial stage of the aquatic red-spotted newt. Their striking color is aposematic or warning since they contain a potent toxin, tetrodotoxin. How do potential predators such as birds (most mammals are color blind) know that red on a salamander is bad but red fruits are edible? Both learning and a genetically determined component may be involved. The northern red salamander is considered to be a tasty mimic of this species.
Box turtle female
On a stroll in the fall woods, you may encounter a box turtle such as this female with a brown iris, slowly moving through the leaves. Box turtles are a very ancient lineage, far older than the dinosaurs, and they live slowly and as long as humans. You can see the numerous growth rings on the scutes, but they cannot be counted accurately in a turtle this old. Box turtles hibernate in shallow scrapes and can resist freezing by producing antifreeze in their tissues.
So enjoy the natural beauties of fall, which are considerable. But soon enough the deep freeze will be upon us and life will have to flee or hunker down for the winter.
Lava reaching skyward
This past Sunday, a group of us Charlottesville folk went to Humpback rocks up on the Blue Ridge (mile 5.8 on the Blue Ridge Parkway). We enjoy being within a twenty minute drive of these higher elevations...and we aren't alone. The parking lot was packed, and the nearby by living farm exhibit gets year around attention. The trip up there is always amazing because the landscape changes so dramatically before ones eyes...and your ears "pop". Interstate 64 climbs diagonally up the mountain cutting through thick deposits of metamorphosed lava. We were time travelers ...traveling forward in time to see denuded trees that will dominate our view down on the Piedmont in a couple of weeks; our trees are still hanging on to leaves...especially the oaks, hickories, and invasives (pawlonia, white mulberry, etc.). We were also traveling through
a complex geologic landscape, ultimately ending up in meta-basalts deposited when central Virginia was well south of the equator, and turned 90 degrees east!
We all met at the parking lot, the kids poured out, and off we went into a woods known for its high black bear population. Some estimates claim that 3 bear live upon every 2 square miles of woods....that's quite a bit. The nearby Shenandoah National Park boasts the largest population of black bears in the east. This is not the time of year to see them though...late spring and early summer is when you can catch them moving about as mating season kicks in.
An immediate thing noticed when one looks up from the parking lot is that a strenuous hike is about to be had. The hike covers over 1000 feet of elevation in less than a mile...with some mild rock climbing thrown in there. Half our kids had to be carried. The others had something else in mind....a race to the top!
We moved up the mountain, over outcroppings of 570 million year old Greenstone (young for Blue Ridge Rocks!). These rocks are old lava flows that once covered great amounts of what are today Virginia and Maryland. The rock is hard, very hard, and thus resists erosion. This greenstone holds up most of the peaks and ridges for most of the way thirteen miles south and over a hundred miles to the north.
The forest was dominated by
,
, and Hickory(
,
, and
).
,
, and
were the dominant understory trees. A few old field relics were scattered about in the forest, including large Flowering Dogwoods and Black Locusts, which were probably the oldest trees we saw at Humpback.
One of the familiar and signifying attributes of the dying black locusts is the polypore it plays host to, the
. So far as I know, it only grows on the Black Locust!
Along the trail we occasionally encountered enormous Chestnut Oaks. Check out the size of the one John's leaning on! Also notice the very distinct bark of the Chestnut oak...so deeply furrowed.
We also found several witchhazel in late bloom (see image with the inset), all but a few had dropped their long and wispy yellow petals and stamens, leaving behind these curved sepals.
All adults and kids (all five under the age of 5) made it to the top! I've tried this on two other occasions, without luck. Must have been somethin in the air! The view was magnificent.
