Habitats and Species of Virginia

poison ivy on cherry tree, Manassas battlefield (Prince William County)
poison ivy on cherry tree, Manassas battlefield
(Prince William County)
interrupted fern, Shenandoah National Park (Greene County)
interrupted fern, Shenandoah National Park
(Greene County)
fire azalea on Warspur trail, Salt Pond Mountain (Giles County)
fire azalea on Warspur trail, Salt Pond Mountain
(Giles County)

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. Manatees and humpback whales swim into the Chesapeake Bay - but they do not stay. Alligators are in North Carolina just south of Dismal Swamp - but none live naturally in Virginia.

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. 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 has magnolia trees and bald cypress growing in Virginia; we are a "southern" state. 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. Our latitude is 1/3 of the way north of the Equator towards the North Pole. We have a temperate, not a tropical climate.

Virginia provides a suitable place to live in different seasons. As seasons change, the 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, birds start flying south for the winter.

Plants lack the option of moving. Even the "walking fern" can only move a few feet a year, at the most. Plants adapt by winterizing. They drop their water-filled leaves that are vulnerable to freezing, drain sap down into the roots, or produce hard-coated seeds that can survive the winter while the annual plant itself dies.

pawpaw in bloom, Merrimac Farm Wildlife Management Area (Prince William County)
pawpaw in bloom, Merrimac Farm Wildlife Management Area
(Prince William County)
beaver activity, Sweet Briar College (Amherst County)
beaver activity, Sweet Briar College
(Amherst County)
box turtle, Fairfax Villa Park (Fairfax County)
box turtle, Fairfax Villa Park
(Fairfax County)

To understand the different ecological niches and biological communities in Virginia, and especially to understand whether the cumulative impacts to those natural areas of development of roads/subdivisions is acceptable, it is necessary to identify individual species that live in Virginia. That's not as easy as distinuishing between a NASCAR race and a football game on the television.

Trying to define the boundaries of life can induce a headache. Are bacteria in the same category as viruses? Should fungi and lichens be treated as one lump or two? Should ferns and flowering plants and conifers (such as pine trees) be three categories... or many, many more? It's tempting to say "this is alive, and that is not" - but are viruses and prions alive?

Simplistic answers may be attractive, but they are rarely useful. Impacts of altering the natural setting can be subtle and cumulative. If a series of boat docks are constructed, with each one disturbing a sandbar in the Clinch River where mussels are reproducing, the total destruction of that population can occur without anyone noticing.

When the state tries to build a highway through an undeveloped natural area using Federal highway funds, government agencies must complete an Environmental Assessment (EA) or occasionally a more-detailed Environmental Impact Study (EIS). The analysis is mandated by the National Environmental Protection Act (NEPA) for projects involving Federal resources. It is common to hear complaints that the species inventory and other aspects of environmental analysis cause too much delay and expense.

NEPA-mandated analysis is designed to help officials decide on the significance of a place, and how alterations in the habitat might created unintended consequences. Some habitats are common in Virginia, and destruction of a few acres of forest may be significant only to the trees and critters that live in that specific location. If an archeological site, historic structure, "specimen tree" of unusual size, or a nest of an endangered species is identified in the inventory of potentially-affected resources, the typical solution is to move the project (such as a highway) a few feet to avoid damaging the resource.

farms, roads, and power lines fragment forests and create open areas, reducing the wood thrush population but increasing the habitat suitable for bluebirds (Salt Pond Mountain, Giles County)
farms, roads, and power lines fragment forests and create open areas,
reducing the wood thrush population but increasing the habitat suitable for bluebirds
(Salt Pond Mountain, Giles County)

But should the road be moved north through that pasture, the one over there with the wildflowers blooming on the edge... or south through that pine plantation? Planted pines are not "natural," after all. However, if you are near the Sussex and Southampton counties, you could be looking at a rare longleaf pine forest that provides shelter for the even-rarer red cockaded woodpecker. Which location is less valuable than the original route? Which habitat for individual species, or which habitat for "ecological community groups" (species that tend to live together), is more valuable?

To answer that question, scientists try to categorize ecological communities, then inventory them, then assess the impacts of the alternatives to the proposed action (such as building a road here vs. there). A taxonomy of places is essential for an apples-to-apples, oranges-to-oranges discussion. Some communities, like species, are "critically imperiled" and ranked as G1, or rare on a global scale. If rare at the national or state level, rankings are N1 (national) and S1 (state).

On the other end of the scale, common/widespread/abundant communities are ranked G5, N5, or S5. In most cases, changes to the landscape in G1 locations create far greater environmental damage than in G5 locations, because it is harder/impossible to replace a G1 community. Typically an EA/EIS will steer decisionmakers to protect the rare places, and put development where it will affect only the common communities.

On a broader scale, a series of communities can be lumped into ecosystems. The Environmental Protection Agency (EPA) has defined four levels of ever-more-detailed ecoregions of Virgiinia.

EPA says "Ecological land classification is a process of delineating and classifying ecologically distinctive areas of the earth's surface. Each area can be viewed as a discrete system which has resulted from the mesh and interplay of the geologic, landform, soil, vegetative, climatic, wildlife, water and human factors which may be present."1

Level III and IV Ecoregions of EPA Region 3
Level III and IV Ecoregions of EPA Region 3
Source: Environmental Protection Agency (EPA)

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 wildflowers 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.

spicebush (Lindera benzoin) is a native understory plant that deer tend to avoid (Chapman/Beverly Mill, Prince William County)
spicebush (Lindera benzoin) is a native understory plant that deer tend to avoid
(Chapman/Beverly Mill, Prince William County)
Japanese stiltgrass (Microstegium vimineum) is a non-native, invasive species that provides little/no food value to native animals in Virginia (Manassas battlefield, Prince William County)
Japanese stiltgrass (Microstegium vimineum) is a non-native, invasive species that provides little/no food value to native animals in Virginia
(Manassas battlefield, Prince William County)

Now look closely at those pine forests - what trees are gowing up underneath the mature ones? Along I-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 quit raising corn or grazing cattle. First weeds fill the fields. 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.

coreopsis on roadside at Rosewell (Gloucester County)
coreopsis on roadside at Rosewell
(Gloucester County)
goldenrod on Dogan Ridge of Manassas Battlefield, (Prince William County)
goldenrod on Dogan Ridge of Manassas Battlefield
(Prince William County)

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.

cedars on left, transforming an old field into a young forest
cedars on left, transforming an old field into a young forest

It's not quite that simple, naturally. Normally, succession without intermittent disturbance would be rare - there's always 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.

with over 40
with over 40" of rain annually in Virginia, trees will grow in abandoned fields and convert them into forests within a century
(Brawner Farm, Prince William County)

Gardeners are well aware of the difference between 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 towards 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 efforts to protect the rare species. There are some people who could eat the same macaroni-and-cheese meal for breakfast, lunch, and dinner too... but if you are more sophisticated in your food selection, you 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 and left their footprints in the sediments. Only in the last 15,000 or so 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. Once the Native Americans began to clear spaces for agriculture, they created new habitats for species such as deer that prefer a mix of forests and fields. Native Americans domesticated the wild wolf, and had dogs as companions - and as a source of food, too. (Lewis and Clark, when in Oregon, grew tired of eating elk and welcomed a meal of dog.)

Starting in the 1500's, Europeans started to bring their species to Virginia. Today, the habitats annd species that inhabit them have been transformed. It is hard to establish a baseline of what species are "native" to the Chesapeake Bay, since ships have carried so many hitchhikers from Europe,, Africa, South America, and the Caribbean. Anglers fishing for bass assume the smallmouth and largemouth are native to the Shenandoah River, when in fact they were unable to get past Great Falls naturally.

Burkes Garden, one of the biologically-rich areas on Southwestern Virginia  (and known sometimes as God's Thumbprint)
Burkes Garden, one of the biologically-rich areas on Southwestern Virginia (and known sometimes as "God's Thumbprint")
Source: US Geological Survey (USGS), Burkes Garden 7.5x7.5 topographic quadrangle (1941)

Animals of Virginia

Bats in Virginia

Birds in Virginia

Chestnuts in Virginia

Blue Crabs in Virginia

Deer in Virginia

Elk in Virginia

Forestry in Virginia

How a Fish Sees Virginia

How Will the Environment of Virginia Change?

Invasive Species in Virginia

Moths & Butterflies in Virginia

Gypsy Moths in Virginia

Natural Resource Organizations (Government/School/Non-Government)

Plants and Communities

Oysters

Submerged Aquatic Vegetation

Threatened, Endangered, Sensitive, and Other "Species of Concern" in Virginia

Vegetation of Virginia

Virginia Ecosystems (the "Big Picture")

Wetlands in Virginia

Wildlife Rehabilitation in Virginia

Zoos in Virginia

historic range of the chestnut, before the blight
historic range of the chestnut, before the blight
Source: US Forest Service

Links

raccoon

References

1. Level 3 Ecoregions of the United States, http://www.epa.gov/bioindicators/html/lv3-eco.html (last checked September 22, 2010)

Recommended Resources

Woodward, Susan L. and Hoffman, Richard L., "The Nature of Virginia," Virginia's Endangered Species: The Proceedings of a Symposium


Virginia Places