Cumberlands and Southern Ridge and Valley Ecoregion
Description & Physiography
Stretching over 500 miles from northern Alabama to southern West Virginia, encompassing approximately 37 million acres in portions of six states, the Cumberland and Southern Ridge and Valley (CSRV) Ecoregion is a highly variable landscape with a complex geologic history.
The highest waterfall and the largest stone arches in the eastern United States are found in the Cumberlands. Likewise, thousands of caves underlie much of the CSRV, including the two largest cave chambers in the East. Overall, the complex geology has created a number of distinct environments that today support a tremendous array of life.
Elevations in the CSRV vary from a minimum of only 160 feet above sea level to over 4,600 feet. The general range of gradients across the ecoregion has resulted in a multitude of habitats for species and natural plant communities -- from broad river floodplains to small, ephemeral streams, high mountains to deep gorges, and dry barrens to mesic forests.
The CSRV lies within temperate latitudes, which has helped to provide a relatively mild climate with favorable growing conditions. Average temperatures across the ecoregion vary from 55° to 62°F in the south and 39° to 57°F in the north. Likewise, the growing season extends for approximately 175 days in the north and 210 days in the south. Annual mean rainfall ranges from 35 to 55 inches across the ecoregion, but may reach as high as 60 inches per year in higher elevations
Plants & Animals
The high biological diversity of the CSRV ecoregion can be attributed to a number of reasons, but mostly to geology, climate, and elevation. Geology played a large role in forming much of the ecological foundation of the area’s biodiversity, while other related factors also contributed to the richness of the flora and fauna. Principally, most of the CSRV escaped glaciation during the Pleistocene Epoch. The north-south orientation of the mountains and valleys allowed species to migrate southward ahead of the advancing ice sheets. As glaciers retreated, species were able to advance northward again. Ultimately, the CSRV became a migratory crossroads of northern and southern species.
The three major river basins that constitute the ecoregion include 18 of the top 20 watersheds in the country for total numbers of vulnerable or imperiled species. In fact, the CSRV contains the number one watershed in the country, the Clinch River, which has 48 imperiled fish and mussel species, including 21 that are federally listed as endangered or threatened. Collectively, the Tennessee and Cumberland Rivers contain the most diverse collection of freshwater animal species in the country, and may possibly represent the most diverse temperate freshwater assemblage in the world.
Plants also constitute an important group of organisms in the CSRV Ecoregion. As a whole, the Southern Appalachians have long been known to harbor an exceptionally rich flora compared to other temperate, hardwood regions of the world. Many of the plant families found in the region represent ancient lineages that occur in few other places on earth. Due to the broad cross-section of terrain and climate, the CSRV captures much of the overall flora of the Southern Appalachians (approximately 3,000 species).
Plants face perhaps the widest assortment of threats throughout the ecoregion. Direct destruction of habitat is believed to be the most pervasive threat. Conversion of plant habitats to agriculture, houses, industry, commercial forestry, and other uses has greatly affected the quality and condition of plant species across the CSRV. As well, indirect activities such as fire suppression and dam construction have disrupted normal ecological processes and decreased the health and vitality of many plant occurrences.
Conditions favorable to humans are very unequally distributed across the ecoregion. Given such inequity of resources, the natural character of the CSRV has been formed predominantly from the struggles of people to secure livelihoods across a disparate landscape. Many of the socio-economic factors that dictated past settlement still prevail today throughout many local
By the time the first Europeans arrived, the landscape they encountered was an open mosaic of forests and grasslands in many places. Early Native Americans had already banded together into the historic tribes known today. The earliest European settlers that came to the region were primarily land seekers of Scotch-Irish descent. Many had come to the New World as indentured servants and fled to the region in search of free land ahead of colonial government sanction.
When coal was discovered in the Cumberlands in the latter part of the 1800’s, many people came to work in the mines. As well, the rich forests of the area had attracted many timber companies. Many of the original land grants for the area had been acquired by timber and coal interests. With the arrival of the railroads, much of the Cumberlands region was readily exploited for both coal and timber. Later, oil and natural gas were discovered in the region. However, again wealthy investors controlled much of the mineral rights. Most people in the region remained relatively poor despite an abundance of natural resources.
Today, the CSRV remains strongly divided along socio-economic lines. The Cumberlands subregions are still sparsely inhabited relative to the SRV. Still, many portions of the SRV region are also rural. Agriculture plays a prominent role in the local economies of these communities. Cattle, tobacco, and row crops such as soybeans and corn are important agricultural commodities. Most farms are relatively small in comparison to other parts of the country, with 100 acres or less in pasture or cultivation on average.
Land ownership patterns also vary greatly across the CSRV Ecoregion. The majority of public lands occur in the Cumberlands region. Beginning in the 1970’s, a large number of public lands were purchased by many states and the federal government from properties owned by timber and coal companies. Overall, almost 3.2 million acres of public land currently exists in the CSRV. Combined across all ownership types (federal, state, local), these lands account for approximately 9% of the total land area of the ecoregion. Given these private ownership patterns, opportunities for landscape-level conservation are generally better in the Cumberlands region.