Habitats and Species of Virginia
Virginia is a great place to live - according to some people. Others can't stand the place.
Plants and animals operate the same way. Some find the places in Virginia, the habitats, to be good neighborhoods. Others visit for a period of time each year, then leave. And a lot of plants and animals are never found naturally in Virginia; this is not the place for them.
Virginia's soil, climate, and even location on the eastern edge of the continent determine which species live here. The effects of the climate are most obvious. We have magnolia trees and bald cypress growing in Virginia - walk around
First Landing State Park, and it's not hard to imagine yourself being in a Louisiana
swamp - but it's too cold here for banana trees or alligators. In the early summer,
the woods are full of bird calls. Come winter, however, and many of the songbirds migrate
south. In return, Virginians get to see juncos and snow geese, visitors from the north who
consider Virginia winters to be mild compared to Canada.
Virginia provides a suitable place to live, but as the climate changes those habitats change. The
most obvious change is in the forests - when the leaves drop, much of the food and shelter
required by some species disappears too. Many species of animals, such as neotropical birds,
adapt to the changing circumstances by picking up and moving - at just about the time students
migrate to college campuses.
Plants lack that option. Even the "walking fern" can only move a few feet a year, at
the most. So they adapt by winterizing - dropping their water-filled leaves that are vulnerable to
freezing, draining sap down into the roots, or producing hard-coated seeds that can survive the
winter while the annual plant itself dies.
Take a close look outside the car window, the next time you are trapped in traffic. Notice the
different types of plants along the roadside. Do this several times, and you'll begin to see the
pattern. Some places are treeless, such as the mowed edges of the roads or the medians in
divided highways. Here you'll find wildflowerrs such as Queen Anne's lace (the big white blooms
that look sort of like an umbrella) and chicory (blue flowers hardy enough to grow among the
gravel). Look at the forested areas, and notice how few wildflowers are visible on the ground.
The trees are capturing all the sunlight, shading out the forest floor beneath. Even at 55 miles per
hour, you can see some forests are thin-needled pine trees and others are broad-leaved oaks,
maples, etc.
Now look closely at those pine forests - what trees are gowing up underneath the mature ones?
Along Interstate 95 in the summer, you can see the sweetgum and other broadleaved species are
the understory, the young trees underneath the overstory of mature pines. In 50 years or so,
those pines will have died - and their replacements will not be more pine tress. Instead, a
broad-leaved forest will replace the pine forest, in a pattern known as "succession."
|
Look at old fields in suburbia, after farmers quite raising corn or grazing cattle. First you'll
see weeds galore fill the field. In the Spring, a species of mustard can carpet the entire field with
yellow. In the Fall, different species (often a Coreopsis or goldenrod) can create the same effect.
But view the field 10 years later, and young trees will be growing in the field. In the limestone
soils of the Valley and Ridge province, look closely and you'll notice (typically) that the trees are
red cedar (Juniperus virginana) rather than the Virginia pine so common on the
Piedmont and Coastal Plain. Look again 20 years later, and the weed-filled field will be a young
forest, often a dense thicket of pines or cedars. If you could come back in 100 years, however,
you'd see the progression to the "final successional stage" or "climax forest" of oaks, hickories,
beeches, etc.
It's not quite that simple, naturally. In the mountains, the hemlocks are part of the final
forest mix. Normally, succession without intermittent disturbance would be rare - there's alays a
hurricane, a forest fire, a disease outbreak every century or so. With humans creating such
disturbance in the environment, our only opportunities to study this process over decades could
be limited to those few areas designated as parks. The story is much more complex than
presented here - but at 55 miles an hour, this is enough to think about...
|  |
Gardeners are well aware of the difference dbetween shade plants (such as ferns) and plants that
require full sun (such as tomatoes). You can appreciate the geography of Virginia's plants without
knowing the names of the trees and flowers. Use your eye to notice where you see things, start
with large patterns such as sunny vs. shady locations, and work your way toards a greater
appreciation of the diversity of habitats and species in Virginia. If you don't see the differences, if
all the plants look the same to you, then it's hard to understand why there's such an emphasis on
protecting the rare species. There are some people who could eat the same macaroni-and-cheese
meal for breakfast, lunch, and dinner too... but hopefully you are more sophisticated in your food
selection, and can be more sophisticated in your understanding of ecological places too.
At one time, the habitats and species of Virginia were very different from what you see
today. In the Triassic, Jurassic, and Cretaceous eras, dinosaurs thumped through "forests" of
Virginia ferns and cycads. Only in the last 15,000 years have humans been one of the species
affecting the habitats in Virginia. Twice, different sets of "discoverers" adapted the resources
here to suit their needs, changing the face of Virginia in the process.
Links
Recommended Resources
Woodward, Susan L. and Hoffman, Richard L., "The Nature of Virginia," Virginia's Endangered Species: The Proceedings of a Symposium
Geography of Virginia