Wednesday, July 29, 2009

Boreal Bog

There are some who believe that the quality of our relationship with nature is profoundly important to our well-being. This hit home as I sat on the boardwalk that winds through the Cranberry Glades, a bog environment in the Monongahela National Forest.

The ecosystem of the Glades formed more than 10,000 years ago. On our continent, it is the southernmost occurrence of a habitat associated with the arctic tundra. Retreating from the glaciers of the Pleistocene Era, northern plant species moved southward.

While the glaciers did not quite reach the latitude of Cranberry Glades, those species migrated just further enough to settle in a welcoming spot--a bowl encircled by ridges at a 3400 foot elevation in what is now known as the Allegheny Mountains of West Virginia. The topography funnels water from rain and snow to form the bog. Cold air flowing down the slopes helps maintain the microclimate that keeps these species happy.
One need not travel to the rainforest to get a biodiversity thrill. An intact bog is full of marvelous and beautiful plants adapted to the acidic conditions.
John Eastman, writes in The Book of Swamp and Bog that experiencing a bog "may bring us as close to encountering true American wilderness as most of us will ever come." Eastman is an impeccable observer and researcher but also reverent. He comments that "experiencing the richness and complexity of wetlands cannot fail to revive and nourish one's own sense of wholeness to a degree beyond common expectation."

I had not yet read Eastman as I sat on the boardwalk. For the last hour time had been suspended as my friend and I wandered in awe through a botanical cornucopia. I photographed plants that I had never seen like pink orchids, cranberries, cotton grass, and carnivorous sundews and pitcher plants. Once or twice I stepped gingerly on the spongy ten-foot-deep layer of sphagnum moss that forms the water-logged surface of the bog.

I saw healthy eastern hemlock trees, their needles fat and glossy, their branches encrusted with white lichen. I glimpsed a shy doe through a screen of red spruce. Circular clumps of cinnamon fern dotted the landscape. Blue sky arched over all. I sensed the secret life of plants as an inaudible hum.

It seemed with each breath, my feeling of calm and "wholeness" grew. I commented to my companion that any person who would visit the Glades could not help but experience a healing of body and spirit.
The rare plant species I encountered at the Glades deserve the honor of individual posts. More to come. ABC Wednesday

Wednesday, July 22, 2009

Alien Invaders

Alien species, non-native species, exotic species. These are plants, animals or other organisms that have been abruptly (compared to natural migrations) introduced to an ecosystem, usually by human doings-often accidentally, but sometimes intentionally. This phenomenon has caused dramatic changes worldwide, and continues to do so.

I recently learned that many of our most familiar "wild" flowers are non-native and have been around for centuries. Seeds hitched across the Big Pond with early European immigrants. Each summer I'm happy to see the 6 foot tall flowering spikes of fuzzy leaved Common Mullein that stand at attention like soldiers reviewing a parade. What country girl hasn't picked a bouquet of Queen Anne's Lace and marvelled at its umbrella of tiny white florets?

These roadside weeds are rather benign, but for an example of negative effects, one word: kudzu. A noxious vine, kudzu strangles and smothers everything in its path. It was aggressively planted by the U.S. government in the 1930's for erosion control before it was discovered that in our humid southern states it grows just too well.

European starlings (Sternus vulgaris) were brought to North America by a man who wanted to seed our continent with all the birds that are mentioned in Shakepeare! The descendants of the original 75-100 birds released in New York's Central Park in the 1890's now number more than 200 million. Starlings have voracious appetites, migrate in flocks of up to 100,000 birds, and have contributed to the decline of the bluebird, purple martin and tree swallow.

Not all non-native species are home wreckers, but those that are earn another moniker: invasive, although this term is passing out of favor in ecological circles. (Truth be told, a native species may be invasive as well, meaning it rapidly colonizes an area, such as the Maryland state flower, the Black-eyed Susan. )

By any name, an exotic invasive species does not "smell" sweet-- but through no fault of its own really. In its homeland, it probably evolved to be in relative harmony with its surroundings. But transplanted to a new environment, it may have few or no natural predators, no competing species, and other species may have no natural resistance to it. The result is imbalance and perhaps irrevocable degradation of indigenous flora or fauna.

Since species are interdependent, when one species goes it can take others with it in a chain reaction. This dynamic has severely impacted the vulnerable islands of Hawaii. Seventy three percent of U.S. extinctions have occurred in Hawaii. Feral goats, pigs and sheep are some of the worst offenders there.

We learned how wolves benefitted the ecosystem when they were eradicated (by homo sapiens) from places like Yellowstone. Without wolves, elk proliferated and began overgrazing vegetation, which in turn affected other species, increased erosion, and impaired water quality. The ecosystem there is now mending due to the much publicized, and controversial, re-establishment of wild and free wolves.

Growing to 60 feet, the American Chestnut was formerly a dominant tree throughout our eastern forests, until a blight hit it early in the 20th century. The culprit? -- a variety of chestnut brought here from Asia that had resistance to the blight. Scientists are working to develop resistant strains of our native tree in hopes of restoring the chestnut to its former place as king of the forest. Doing so could have a substantial impact on mitigating climate change.

It is sobering when I consider not only changes I've witnessed in a half century of outdoor wanderings, but just recently. This past spring I saw infestations of garlic mustard in shady glens along the Potomac, choking out trillium, mayapples (see photo left), jacks in the pulpit, and other delicate native wildflowers that were flourishing only a few springs ago.

From my childhood, I remembered the path at Cunningham Falls State Park as a magical tunnel formed by the delicately needled branches of eastern hemlock trees. Wanting to get an early start on sharing my love of nature with my grandson, I took him there when he was only one year old. The magic remained. While perhaps not as plentiful, the hemlock branches still drooped gracefully above us like tiers of shyly lowered eyelashes. My grandson is now almost five years old. On a recent solitary visit, I felt like a survivor on a battlefield. The skeletons of eastern hemlock trees littered the forest floor or stood gray and silent like ghosts.

In this heavily used park, where biodiversity has already been severely diminished by grazing white-tailed deer, I suspect the hemlocks may have been even less resistant to the Wooly Adelgid-an introduced aphid-like pest. To add insult to injury, Japanese Stilt Grass was making rapid headway in crowding out native Lady ferns. (Where's Waldo the fern?) The overall effect was one of barren sterility.

Young families walked past me as I stood shell-shocked. They were blissfully unaware of what they had missed. But I knew, and mourned their loss. Especially on behalf of the children.

At my feet, a huge black beetle scurried at a surprising pace across the path to avoid being trampled. He frantically pulled some leaf litter over his head and body, obscuring not only himself but his own vision. Although tempted, I didn't disturb him. I knew how he felt.

ABC Wednesday

Wednesday, July 8, 2009

A Terrible Beauty

After following the gravel road for some time, my friend and I at last stood at the entrance to the virgin hemlock forest. The sign said "Untouched by human hands." Loggers had spurned the timber here as not worth the trouble. Spread out over more than a mile, the 126 acre protected tract of forest follows a steep ravine. Woven through its heart like a silver ribbon is a crystal clear mountain stream.

The trail was clearly blazed, but seemed seldom tramped by human feet. Huge windfalls remained where storms had felled them, and scrambling over the third barrier of wayward tree trunks, I got the message. Slow down. Walk with intention and reverence. This is a lost world, not the place for an idle stroll.

It did seem a holy and enchanted place, with a tinge of mystery, even menace. We might have traveled back in time when more ancient creatures claimed the earth. We breathed in the moist air, perpetually freshened by the respiration of green and growing plants. The forest duff beneath our boots was thick and undisturbed. We wandered at the broad feet of oaks, hickories, and tulip poplars that loomed into the canopy high above us. The silence was broken only by intermittent calls of unfamiliar birds and the soft music made by rock and water.

Monumental eastern hemlocks (Tsuga canadensis) clustered in the more open marshy areas where they had the best access to the light. Viewed from below, their perfectly straight, tapering forms looked like stately columns left standing in some gigantic ruined temple. Sadly, what had eluded the loggers had succumbed to the Wooly Adelgid, an introduced, aphid-like pest that is decimating hemlocks throughout the eastern forests. The oldest hemlocks here were already dead or dying, trunks stripped except for the highest branches, any remaining needles gray and sparse. The shrub-sized hemlocks and seedlings we saw along the trail seemed as yet unaffected. Admiring their glossy blue-green needles, I could imagine what had been lost.

Waist high ferns grew everywhere in broad swathes, luxuriating in the shady damp microclimate. An extensive patch of club moss raised its many "thumbs" like miniature candlabra. From a high place, I spied a circle of stop-sign red in a patch of sun by the stream below. Using my binoculars, I was able to make out a dinner plate sized mushroom.

After about an hour, we began retracing our steps, and stopped to rest on a log. A bird lighted on a nearby branch at eye level. It had an olive green body and a gray crown. A fat lime-colored catapillar wriggled in its beak. I tried to memorize the bird's markings and behavior for a later perusal of Peterson's Guide. We stood up to leave, with my friend stepping ahead into a sunny spot. Suddenly an extremely loud buzzing sound exploded from several feet directly in front of him. At once my every sense was on the alert. It was unmistakably a timber rattlesnake! (Crotalus horridus). My friend stood frozen as the snake began slowly undulating itself uphill to the shelter of another nearby log. I instinctively jumped up on top of the log we had been sitting on.

My initial reaction of fear almost immediately turned to a sense of privilege at the chance to see this reptile in its natural habitat. Emerging from the other side of the log, the rattler made no further attempt to escape. Although deadly, this species is apparently mild-tempered and does not usually strike without direct provocation.

The snake curled its almost 3 foot long body into a classic posture, facing us, visibly relaxing in the warmth of the sun's rays, displaying its rattle and head nestled within its coils. My friend took some photos while I used the close focus feature of my binoculars to take in every detail.

The snake looked almost unreal it was so vividly patterned. The scales stood out in sharp relief in the bright light. The triangle shaped head that houses the venom sacs, the coldly staring eye, the thick muscular body that one could easily imagine forcefully striking, the rattle held aloft in an insouciant dare--all combined to evoke danger and perhaps even 'evil'. But I found myself admiring the beauty of the animal and the evolutionary process that had gifted it with so many unique adaptations. Due to their retractible fangs and venom sacs-which they share with other pit vipers-and the warning buzzer at the end of its tail, rattlesnakes are thought to be the most highly specialized of all snakes.

Not being a specialist in reptiles, I still could tell this was a very healthy specimen, a successful hunter, and probably a successful breeder too. As I gazed at the rattler, I felt as if time itself was coiling into a spiral. How many generations of rattlers have existed in this ravine over the centuries, even millennia, preying on the small mammals, birds, frogs and other snakes who live here?

With that unsettling sound still "rattling" in our heads (a rattlesnake's warning can be as loud as 60 to 80 decibels from a few feet away), we continued back to the car, our eyes scanning the trail ahead of us much more carefully. My so-called 'reptilian' brain had been awakened. I felt my senses had become sharper and even more attuned to the primeval surroundings. The visit to the lost world would sustain me through many hours of office meetings and computer glitches.

Photos by Bill Stachoviak

Tuesday, July 7, 2009

Endless Variations on a Theme

As my perceptions become more acute on this journey into nature, I am more and more in awe of the endless variety of plant shapes and patterns of growth and how/why they evolved. For example, I attempted to "key" out a huge white flowering "weed" found near the C&O Canal towpath near Harper's Ferry, WV this spring. Using the Newcomb's Guide to Wildflowers, I wasn't having much luck, until I realized the plant's resemblance to Queen Anne's Lace (an alien import). I broke off a leaf, crumbled it, sniffed it, even tasted it! Yep, that carroty scent. (Queen Anne's Lace is known as a wild carrot.) This led me to the right page in the book.
The plant was in the parsley family-a common species known as Cow Parsley (Anthriscus sylvestris) a native to Europe, Africa and Asia, that often grows to over six feet. Since Newcomb's Guide uses a keying method that is based on numbers of petals and leaves and their arrangement, I decided to count the stems in the umbel, and came up with 29. That seemed wierd, so I counted again. And again. Still 29. That brought up the question: what is the "math" behind nature's botanical design?
I had heard about Fibonacci numbers but had never studied them. Fibonacci was a mathematician in the Middle Ages. The numbers emerged as he studied the reproduction patterns of rabbits! The numbers are an infinite series, beginning with the numeral 1, where each successive number is the sum of the two numbers that appear directly before it. Design based on these proportions approximates the "golden ratio," also known as the golden mean, golden number or divine ratio. Expressed as a decimal, the golden ratio is approximately 1.6 , referred to as Phi.
Growth patterns that follow the golden ratio are rampant in nature. Two examples often cited are the spirals of a nautilus shell and seed head of a sunflower. The golden ratio is seen as well in the proportions of the human body--even the structure of DNA is a demonstration of the golden ratio. Not surprising that in classic art and architecture, the golden ratio was considered to be the foundation of beauty.
But back to Cow Parsley. The number 29 was not listed in the Fibonacci series of numbers. But there is another series that models the golden ratio, developed by Lucas, the mathematician who "discovered" Fibonacci's work. This series of numbers is also very prevalent in the growth patterns of plants. The Lucas series replicates the "sum of the previous two numbers" feature, but starts with 2 followed by 1. And there it was, my Cow Parsley's "29." Amazing what trying to identify a weed can lead to....! Now I see the golden ratio everywhere, as in the thistle bud at top.