Distribution of Upland Hardwood Forests
Upland Hardwoods Ecology and Management Research Work Unit, SRS
Upland hardwoods unit researchers cooperate with land management agencies across North America to continue to build a comprehensive ecoregion approach to site classification. Ecoregions are defined based on similarities in plant and animal species, climate, soils, and the general topography of the landscape. This method starts with the very broad geographic ecoregions, then focuses on progressively smaller areas—subregions, landscapes, and finally land units. A definitive national ecoregion map was published in 1994. In 2005, a revised national map was produced of ecological subregions that includes digital databases for physical (temperature, precipitation, soils) and vegetation data for each subregion.
Upland Hardwoods Research Work Unit cooperators include:
- University of KentuckyVirginia Polytechnic Institute and State University
- Clemson University
- University of Tennessee
- University of Missouri at Columbia
- Alabama A&M University
- North Carolina State University
- University of the South (Sewanee)
- Mississippi State University
- North Carolina Wildlife Resources Commission
- Alabama Wildlife Resources Commission
- The American Chestnut Foundation
- The Nature Conservancy
- Missouri Ozark Forest Ecosystem Project
- Stevenson Land Company
- Daniel Boone National Forest
- Bankhead National Forest
- Pisgah National Forest
- Ozark-Ouachita National Forest
Eastern Broadleaf Forest
Continental climate of cold winters and warm summers. Annual precipitation is greater during summer, water deficits infrequent. Topography is variable, ranging from plains to low hills along the Atlantic coast. Interior areas are high hills to semi-mountainous, parts of which were glaciated. Vegetation is characterized by tall, cold-deciduous broadleaf forests.
Midwest Broadleaf Forest
Continental climate with warm to hot summers. Frequent growing season water deficits. Flat to hilly terrain with features associated with former glaciation. Vegetation consists of cold-deciduous, hardwood-dominated forests with a high proportion of species able to tolerate mild, brief, periodic drought during the late summer.
Interior Broadleaf Forest
Continental climate with hot summers. Summer soil moisture deficits are common. Vegetation is broadleaf deciduous forests with a somewhat open canopy and greater density of species tolerant of drought.
Appalachian Broadleaf Forest
Temperate climate with cool summers and short, mild winters. Annual precipitation is plentiful and evenly distributed with short periods of water deficit. Landscapes are predominantly mountainous. Forest vegetation is characterized by a closed canopy of mainly oaks; broadleaf forests change to coniferous or shrub lands at higher elevations. Ice storms are an important broad scale disturbance. High-intensity rain storms are associated with remnants of occasional hurricanes; lightning-caused fires are uncommon.
Continental climate with cold winters and hot summers. Landscape is low mountains formed by dissection of sedimentary formations. Forest vegetation is predominately broadleaf deciduous species that can tolerate brief periods of drought.
Southeastern Mixed Forest
Generally uniform maritime climate with mild winters and hot, humid summers. Annual precipitation is evenly distributed, but a brief period of mid to late summer drought occurs in most years. Landscape is hilly with increasing relief farther inland. Forest vegetation is a mixture of deciduous hardwoods and conifers.
Ouachita Mixed Forest
Continental climate, with short, cool winters and long, hot summers. Precipitation occurs throughout year, but summers are dry. Vegetation consists of mixed needle leaf and cold-deciduous broadleaf forests.
Outer Coastal Plain Mixed Forest
Humid, maritime climate; winters are mild and summers are warm. Precipitation is abundant with rare periods of summer drought. Upland forest vegetation is dominated by conifers, with deciduous hardwoods along major floodplains.
Lower Mississippi Riverine Forest
Climate with warm winters and hot summers. Precipitation occurs throughout the year with minimum in fall. Much of this subregion is influenced by periodic flooding of the Mississippi River.
Prairie Parkland (Temperate)
Continental climate with cold winters and hot summers. Moderate amounts of precipitation that occurs mainly during growing season. Landform is mainly plains with areas of low hills. Vegetation was once herbaceous with woodland of scattered deciduous broadleaf trees along floodplains of major rivers; almost all has now been cleared for agriculture.
Prairie Parkland (Subtropical)
Modified maritime subtropical, humid climate of relatively warm winters and hot summers. Moderate amounts of precipitation occurring during summer. Landforms are plains with low hills. Vegetation is mainly herbaceous with areas of deciduous broadleaf woodland, particularly along floodplains.