Ecology
Ecology
The Wolf River watershed provides a healthy home for a wide variety of flora and fauna, especially in its rural upper reaches. More than 200 species of birds including Bald Eagles have been verified in recent surveys, and beavers, otters, foxes, bobcats, raccoons, and other mammals are common.
Numerous amphibian and reptile species are found in the Wolf River watershed, especially in its floodplain wetlands. The river itself hosts 67 species of fish including rare species such as the naked sand darter and piebald madtom, and twenty-five species of native freshwater mussels. Rare plants such as copper iris and southern twayblade orchid grow in the Wolf’s bottomlands, and more than 430 plant species have been identified in the Ghost River State Natural Area alone.
The Wolf River flows across a bed of soft alluvial soil, its channel meandering back and forth across a wide floodplain. The floodplain forests along the Wolf River are composed of plant species that have adapted to seasonal flooding that usually occurs in winter and spring. There are two main types of floodplain forests in the Wolf watershed: cypress-tupelo and bottomland hardwood. True wetland tree species such as bald cypress and water tupelo are able to live in wet conditions for most of their lives. Hardwood trees such as swamp chestnut oak and water oak are very tolerant of flooding but cannot survive a constant aquatic habitat. Thus, bottomland hardwood ecosystems exist at a slightly higher and drier elevation than cypress-tupelo swamps and are dominated by various species of oak and hickory trees. The Wolf River Watershed also includes upland forests with unusual species such as the Sand Post Oak and Prickly Pear, managed grasslands where you can sometimes hear the calls of the Eastern Bobwhite, and altered urban and agricultural habitats.
All of the plant and animal species in the Wolf River watershed have one thing in common: they depend on natural habitat to survive. These species are uniquely adapted to fill a particular niche in the Wolf River watershed, whether that niche is in a leafy treetop or a muddy riverbed, and each species is important to help maintain the balance of the larger ecosystem. When an ecosystem is altered by human activities, such as forest clearing and wetland drainage, the species within that ecosystem are placed at risk. By protecting land, the Wolf River Conservancy protects not only the aquifer recharge and water quality services of the Wolf River watershed, but its rich biodiversity and complex ecology as well.
The Wolf River floodplain and watershed is important habitat for over 250 species of breeding and migrating birds that utilize upland and riparian forests, wetlands, and grasslands. Five rare bird species occur in the watershed, including wood thrush and black-crowned night heron. Other notable species include the neotropical migrants such as prothonotary warbler and summer tanager, birds of prey such as Mississippi kite and bald eagle, wild turkey and bobwhite quail, herons, bitterns, and numerous waterfowl. Common mammals now include white-tailed deer, red fox, bobcat, coyote, beaver, muskrat, mink, skunk, opossum, armadillo, raccoon, and numerous rodents and bats. There are two rare mammal species, Rafinesque’s big-eared bat and the star-nosed mole. Red wolves, cougars, and black bears were largely extirpated from the watershed by the early 20th century.
Amphibian populations in the Wolf River watershed include 18 frog and toad species, such as bullfrog, green frog, northern cricket frog, bird-voiced treefrog, green treefrog, and barking treefrog, and 12 salamander species, including the marbled and dusky salamanders. There are 21 species of snakes in the watershed, including the Mississippi Green Water Snake, listed as “in need of management” by Tennessee Wildlife Resources Agency (TWRA), 6 species of lizards, and 10 species of turtles, including the state threatened alligator snapping turtle.
Insects and other invertebrates are extraordinarily diverse and abundant in the terrestial Wolf River watershed. Notable among them is the newly discovered Cypress Firefly (Photuris walldoxeyi Faust) which flashes over the swamps along the Wolf River in the Ghost River and Clark State Natural Areas, and the Yucca Giant Skipper in the Wolf River Wildlife Management Area. These invertebrates are a vital part of the ecosystems they inhabit, providing food for nesting birds and many other species.
For more information on Tennessee mammals, birds, reptiles, amphibians and insects, visit the Tennessee Watchable Wildlife website. The Tennessee Ornithological Society’s Memphis chapter is another great resource for birds in our area. Or just learn more here and here.
About 42% of the Wolf River Watershed is forested, with oak-hickory uplands and the woody wetlands in the floodplains of the Wolf River and its tributaries. Urban areas occupy about 16% of the watershed, and agricultural land in row crops and pasture makes up most of the remainder (39%). The floodplain remains forested through the urban metropolitan area in the lower third of the Wolf River, giving way to mostly agricultural land in the watershed uplands.
There are over 430 plant species documented in the Ghost River State Natural Area in Fayette County (TDEC), a reflection of the diversity of plant communities and resulting species richness found in the Wolf River watershed, e.g., swamp, scrub-shrub, marsh, open water, riparian, bottomland, flats, forested uplands, managed fields and urban areas. The river bottoms are dominated by cypress and tupelo in permanently flooded areas, and oaks and hickories on higher ground, including water oak, willow oak, cherrybark oak, nuttall oak, swamp chestnut oak, shagbark hickory, pignut hickory and others. Common understory species include green ash, pawpaw, red buckeye, roughleaf dogwood, American holly, elderberry, pokeweed, and many others. Aquatic vegetation includes duckweed, bur-reed, spatterdock, arrowhead, arrow arum, coontail, rushes and sedges. Nine rare plants listed by the Tennessee Natural Heritage Program include wetland species such as the endangered Southern Twayblade Orchid, the Blue Mudplantain, and the Copper Iris; the Wolf River watershed also encompasses a unique upland Sand Post Oak community. Along the urban Wolf River, hydrologic changes from channelization have led to the intrusion of exotic invasive species such as privet (Ligustrum sp.) and Japanese honeysuckle. In general, the plant communities are healthier and more diverse in less developed and hydrologically altered parts of the watershed.
Use the following resources for more information on Tennessee plants and trees: Tennessee Natural Heritage Program Rare Plants List, Tennessee Native Plant Society, Tennessee Urban Forestry Council, Native Plant Finder – National Wildlife Federation, Lady Bird Johnson Wildflower Center.
There are 67 species of fish which are known to occur in the Wolf River from a handful of surveys on various river sections. These species represent 13 fish families, ranging from big river fish such as drums and redhorses near the river's mouth to sensitive habitat specialists like madtoms and darters near its origin in Mississippi. Most people are familiar only with those species considered gamefish, i.e., largemouth bass, bluegills, crappie and other members of the Sunfish Family, and the channel catfish, flathead catfish, and bullheads of the Catfish Family - and perhaps a few exotic species now living in parts of the Wolf such as Eurasian and silver carp. The many small fish which are collectively referred to as "minnows" actually comprise at least 14 different Wolf River species. The Catfish Family (Ictaluridae) includes the miniscule madtoms in addition to their much larger gamefish relatives. The 13 fish families in Wolf River waters include oddball families represented by a single species such as the bowfin (Amiidae), the pirate perch (Aphredoderidae), the live-bearing mosquitofish (Poeciidae). Wolf River fishes are astonishingly diverse in their life history and behavior, from the bottomfeeding northern hogsucker (Catostomidae), to the nest-building flier (Centrarchidae), to the burrowing, non-parasitic least brook lamprey (Petromyzontidae). Rare fish of the Wolf River include the blue sucker, the piebald madtom, and the naked sand darter. This diversity would likely be greatly diminished without the restoration and protection efforts undertaken by the Wolf River Conservancy and its partners over the years.
In addition to fish, 25 freshwater mussel species occur in the Wolf River included 3 species listed by Tennessee Wildlife Resources Agency (TWRA) as threatened, endangered or of special concern - the fatmucket, the southern rainbow, and the southern hickorynut. Mussels are most abundant in the upper Wolf River though some species live in the borrow pits along the urban river. The exotic Asian clam (Corbicula fluminea) is common in the Wolf’s sandy riverbed; its impact on the ecology of the river is currently unknown. The US Forest Service has documented 8 species of crayfish in the Mississippi portion of the Wolf, and there are likely to be others which are not represented in samples to date.
Many other small aquatic crustaceans, insects, spiders, and worms - and innumerable microorganisms - are key components of Wolf River ecosystems. Learn more here.
The Wolf River is one of several western Tennessee-northern Mississippi streams that flow from Coastal Plain uplands toward the northwest to the lower Mississippi River. The Wolf River watershed comprises 522,000 acres, including much of the city of Memphis, which relies on the underlying Memphis Sand aquifer recharged in part by the Wolf River watershed as its public water source. Primary tributaries of the Wolf River include the North Fork of the Wolf River, Indian Creek, Shaws Creek, Grays Creek and Fletcher Creek from the north, and Grays Creek (Mississippi) and Clear Creek from the south.
The Coastal Plain is one of the North American physiographic provinces - areas distinguished by unique landforms. Other nearby physiographic provinces include the Mississippi Alluvial Valley and the Highland Rim. The Wolf River originates in and flows through the Coastal Plain, starting in the Southeastern Plains level III ecoregion and flowing through the Mississippi Valley Loess Plains level III ecoregion. The origin of the Wolf River is typically attributed to small, spring-fed Baker’s Pond, in northeastern Benton County, Mississippi. The river is fed by numerous spring-fed tributaries draining from sand deposits in the Paleogene Wilcox and Claiborne geologic formations. The elevation of the Wolf River drops 106 m between Baker’s Pond and the Mississippi River, giving an average stream gradient of 0.7 m/km. The entire length of the river flows on non-consolidated sand, silt, or clay sediments. Subtle active tectonic processes also influence the path of the Wolf River channel.
The Wolf River is a low-gradient, sandy bottomed stream with a sinuous or meandering channel, sometimes divided into smaller braided channels, flowing through high-quality riparian wetlands in its upper reaches. The Wolf River is channelized for 12 km in its upper reach in Mississippi, and for the lower 37 km in Shelby County, Tennessee.
1. Provide water. Because water is vital to all forms of life, the simplest way to help wildlife is to provide a safe source of clean water.
2. Plant Native. Using trees, shrubs, and other plants native to the Mid-South helps to support local species and local ecosystems. For more information, visit the TN Native Plant Society and look for local native plant sales and vendors. Learn more here and here.
3. Create Habitat. Even on a small scale, any outdoor space that provides food, water, cover, and places to raise young can become a home for insects, birds, and other wild creatures. Learn more here.
4. Leave the leaves. The leaves which fall from trees each autumn, especially oak leaves, are a rich source of nutrients and shelter for overwintering butterflies, caterpillars, beetles and many other small organisms which are an important part of the food web. If it’s not possible to leave the leaves where they fall, think about raking them into flower beds or into a pile where they can decompose naturally. Learn more here.
5. Avoid or reduce pesticides, herbicides, and fertilizers. Lawn chemicals can harm wildlife directly or indirectly and wash into storm drains and waterways, harming water quality.
6. Reduce or eliminate outdoor lights. Fireflies and other nocturnally active animals depend on darkness for courtship and camouflage. Too much light pollution in cities not only disrupts wildlife, but also makes it difficult for people to experience the beauty of fireflies and starlight.Learn more here.
7. Keep cats indoors. Cats can be wonderful pets, but cats outdoors are an environmental problem. Cats are not native to North America and kill billions of wild birds and other animals every year, while they can easily be harmed themselves. Learn more here.
8. Pick up litter anywhere. Litter can cause great harm to wildlife through entanglement or ingestion, and it can also end up in our waterways where it diminishes water quality.
9. Buy shade-grown coffee. Coffee grown under a canopy of trees supports more wildlife, including the migratory birds which arrive in the Mid-South each spring. Learn more here.
10. Reduce your carbon footprint. Climate change impacts both people and wildlife. From composting to turning off lights to planting trees, there are many ways to reduce carbon footprint. Learn more here.
11. Become a Citizen Scientist. Smartphone app’s such as Ebird and iNaturalist make it very easy to contribute your observations to large databases used by scientists and conservationists to study the natural world.
12. Support conservation. As a certified local land trust, the Wolf River Conservancy has helped to protect more than 20,000 acres in the Wolf River watershed so far. There are conservation organizations working at the local, state, national and international level.
