M221-Central Appalachian Broadleaf Forest-Coniferous Forest-Meadow Province

This province has a temperate climate with cool summers and short, mild winters. Annual precipitation is plentiful and evenly distributed with short, infrequent periods of water deficit. Landscapes of the province are predominantly mountainous but sections vary in predominant elevation, Ice storms are an important broad scale disturbance. High-intensity rain storms are associated with remnants of occasional hurricanes; lightning-caused fires are uncommon in the humid environment of this province. Loss of American chestnut resulting from an introduced pathogen was a major disturbance to the canopy of most forests during the 1920s. geologic substrate, and physiography. Forest vegetation is characterized by a closed canopy of deciduous, xerophytic tree species, mainly oaks, although many mesophytic species occur on lower slopes and in mountain valleys; broadleaf forests change to coniferous or shrub lands at higher elevations.

The A.T. HUC-10 shell intercepts 4 sections and 10 subsections within this province.

M221A-Northern Ridge and Valley Section (4 subsections)

M221B-Allegheny Mountains Section (1 subsections)

M221C-Northern Cumberland Mountains Section (1 subsections)

M221D-Blue Ridge Mountains Section (4 subsections)

GPP: Gross Primary Productivity (GPP) is a measure of the amount of organic carbon (C) fixed by photosynthesis in an ecosystem. GPP is a fundamental property of ecosystems and provides a measure of forest health. GPP was calculated from the 1 km 8-day product (MOD17A2) from 2000 to 2011, which is based on a light use efficiency model that incorporates MODIS LAI/FPAR data and meteorological data from a General Circulation Model (Nemani et al., 2009). Urban areas were excluded from this summary.

Phenology: Land surface phenology (LSP) is a measure of landscape dynamics reflecting the response of vegetated surfaces to seasonal and annual changes in the climate and hydrologic cycle. LSP has been studied in the context of ecosystem responses to climate change and for monitoring changes in vegetation life cycle events. LSP is derived from the Normalized Differential Vegetation Index (NDVI), which provides a measure of vegetation greenness on the land surface. NDVI was calculated from the 500 m 16-day MODIS Vegetation Indices product (MOD13A2) to evaluate interannual changes in peak NDVI (Nemani et al., 2009) from 2000 to 2011. Vertical lines indicate the timing of the annual onset of greenness, i.e. the start of the growing season (SOS). Urban areas were excluded from this summary.

Snow Cover: Snow cover is summarized as a percentage of the total subsection area, with a trend line fit to the annual snow cover on April 1st. Snow cover was calculated from the 500 m 8-day MODIS snow cover product (MOD10A2) from 2000 to 2011. In this product, snow is detected using a Normalized Difference Snow Index that is estimated using daily data from red, near infrared and shortwave infrared wavelengths. In the MOD10A2 8-day composite snow cover product, a pixel is identified as snow if snow is present on any of the eight days (Nemani et al., 2009). Urban areas were excluded from this summary.


M221A-Northern Ridge and Valley Section

This section has broad, shallow, northeast-southwest parallel valleys underlain primarily by carbonate formations separated by low ridges having sandstone cap rocks. The oak-hickory cover type makes up most of the forests. (Photo: USDA Agricultural Research Service)

Subsection M221Aa: Ridge and Valley

Area (Hectares): 629009

Annual GPP: MODIS Total Annual GPP

GPP: MODIS GPP

Phenology: Start of Season, MODIS NDVI

Snow Cover: % Snow Cover on April 01


Subsection M221Ab: Great Valley of Virginia

Area (Hectares): 748749

Annual GPP: MODIS Total Annual GPP

GPP: MODIS GPP

Phenology: Start of Season,MODIS NDVI

Snow Cover: % Snow Cover on April 01


Subsection M221Ac: Northern Ridge and Valley

Area (Hectares): 571024

Annual GPP: MODIS Total Annual GPP

GPP: MODIS GPP

Phenology: Start of Season, MODIS NDVI

Snow Cover: % Snow Cover on April 01


Subsection M221Ad: Northern Great Valley

Area (Hectares): 566346

Annual GPP: MODIS Total Annual GPP

GPP: MODIS GPP

Phenology: Start of Season, MODIS NDVI

Snow Cover: % Snow Cover on April 01


M221B-Allegheny Mountains Section

This section has a maturely dissected plateau characterized by high, sharp ridges, low mountains, and narrow valleys. Bedrock consists of shales, siltstones, carbonates, and sandstones. Forest vegetation consists of oak-hickory and maple-beech-birch cover types. (Photo: Monongahela National Forest, USDA Forest Service)

Subsection M221Be: Western Allegheny Mountain and Valley

Area (Hectares): 74222

Annual GPP: MODIS Total Annual GPP

GPP: MODIS GPP

Phenology: Start of Season, MODIS NDVI

Snow Cover: % Snow Cover on April 01

 


M221C-Northern Cumberland Mountains Section

The terrain consists of long monoclinal mountains and dissected uplands. Rock formations are level-bedded sandstones that have been eroded to form mountainous terrain. Forests are the oak-hickory cover type. This section is higher elevation than adjacent map units, which contributes to its ecological significance. (Photo: National Park Service)

Subsection M221Cb: Eastern Coal Fields

Area (Hectares): 20377

Annual GPP: MODIS Total Annual GPP

GPP: MODIS GPP

Phenology: Start of Season,from MODIS NDVI

Snow Cover: % Snow Cover on April 01

 


M221D-Blue Ridge Mountains Section

The surface of this section is a gently west-sloping plateau defined on the east by a steep escarpment rising 300 m above section 231I. Topography consists of moderately high (1,000 - 1,500 m), highly weathered mountain ranges, with scattered high-elevation (2,000 m) peaks. The Precambrian-Cambrian bedrock geology is mostly metamorphosed gneisses and schists formed from recrystallization of non-carbonate sedimentary, volcanic, or igneous parent rock material. Soils are deep, well-drained, acidic (pH<5.5), infertile sandy and gravelly loams; surface horizons of high-elevation frigid soils have a high organic content.

Vegetation is forests consisting of oak-hickory, white-red-jack pine, and oak-pine cover types; above 1,500 m elevation forests become dominated by coniferous spruce-fir. Evergreen ericaceous shrubs occupy the understory of many dry ridges. Most gentle lower slopes were cleared for subsistence agriculture during the 1800s and most forests had been selectively logged by the early 1900s. Rainfall is highly variable, ranging from >2,000 mm in areas along the escarpment that are influenced by orographic uplift, particularly near section 231I in South Carolina, to <1,250 mm in the nearby Asheville basin, which is situated in a rainshadow. The climate of section M221D is cooler and wetter than that of adjoining sections. Characteristic fauna includes northern flying squirrel and Canada warbler of high-elevation forests, Southern Appalachian brook trout associated with cold water of high-energy streams, and a high diversity of salamanders. (Photo: H.McNab, USDA Forest Service)

Subsection M221Da: Northern Blue Ridge Mountains

Area (Hectares): 621760

Annual GPP: MODIS Total Annual GPP

GPP: MODIS GPP

Phenology: Start of Season, MODIS NDVI

Snow Cover: % Snow Cover on April 01


Subsection M221Db: Central Blue Ridge Mountains

Area (Hectares): 52851

Annual GPP: MODIS Total Annual GPP

GPP: MODIS GPP

Phenology: Start of Season, MODIS NDVI

Snow Cover: % Snow Cover on April 01


Subsection M221Dc: Southern Blue Ridge Mountains

Area (Hectares): 1067455

Annual GPP: MODIS Total Annual GPP

GPP: MODIS GPP

Phenology: Start of Season,MODIS NDVI

Snow Cover: % Snow Cover on April 01


Subsection M221Dd: Metasedimentary Mountains

Area (Hectares): 752447

Annual GPP: MODIS Total Annual GPP

GPP: MODIS GPP

Phenology: Start of Season, MODIS NDVI

Snow Cover: % Snow Cover on April 01

Province and section descriptions adapted from:

  • McNab, W. H., & Avers, P. E. (1994). Ecological subregions of the United States, section descriptions. USDA Forest Service, Ecosystem Management.
  • Nemani, R., Hashimoto, H., Votava, P., Melton, F., Wang, W., Michaelis, A., ... & White, M. (2009). Monitoring and forecasting ecosystem dynamics using the Terrestrial Observation and Prediction System (TOPS). Remote Sensing of Environment, 113(7), 1497-1509.