Land Cover Trends Project

Central Appalachians

By Kristi L. Sayler 1

Click to see available downloads for this ecoregion

map of Central Appalachians Ecoregion

Figure1.  Central Appalachians and surrounding ecoregions.  The 32 randomly selected 100-km sample blocks are shown along with land use/land cover from the 1992 National Land Cover Dataset.

 

Ecoregion Description

 

The Central Appalachian ecoregion stretches from central Pennsylvania through West Virginia, Maryland, Virginia, and Kentucky and into northern Tennessee (Omernik, 1987). The ecoregion covers approximately 59,800 km2 (23,089 mi2) (fig. 1) and is about 89 percent forested.  It is primarily a high, dissected, rugged plateau composed of sandstone, shale, conglomerate, and coal.  Local relief varies from less than 15 m (50 ft) to more than 594 m (1,950 ft), and the highest mountain elevations range from about 366 to 1,402 m (1,200 to 4,600 ft) (Woods and others, 1996).  The rugged terrain, cool climate, and infertile soils limit agriculture and result in a mostly forested land cover.  A mixed mesophytic forest with areas of Appalachian oak and northern hardwood forest cover the high hills and low mountains (fig. 2).  Coal mining is common in the ecoregion and is one of the major drivers of change (fig. 3).  The agricultural lands of the ecoregion are located in the valleys, where the growing season can last up to 165 days (Woods and others, 1996) (fig. 4).  The main agricultural activities include livestock and dairy farming and Christmas trees growing on plantations.  The climate of the Central Appalachians is variable because of topographic influences in the region.  Precipitation is distributed rather uniformly throughout the year, but the late summer and early fall seasons tend to be drier, with an average annual precipitation of about 1,125 mm (45 in) (Raitz and Ulack, 1984).

 

Contemporary Land Cover Change (1973 to 2000)

 

The overall spatial change in the Central Appalachians was 9.1 percent from 1973 to 2000 (fig. 5).  This was a moderate amount of change in comparison to the other eastern ecoregions. Most of the change was closely tied to coal mining in the ecoregion. An estimated 5.9 percent of the ecoregion changed only once, and the percentage of area undergoing multiple changes was estimated at 3.2 percent (table 1). Most of the multiple-change areas reflected different stages of land cover, including forest, mechanically disturbed, mining, and grassland/shrubland, as coal mines became established, expanded, an then eventually closed down and were abandoned or reclaimed.  The sample blocks with the highest change were concentrated in coal mining regions.  The total change per time period ranged from 2.5 percent to 4.1 percent (table 2). Our average annual rates of change show that the 1986 to 1992 period had the highest rate of change with a rate of 0.6 percent per year (table 2 and fig. 6). This was likely because of a resurgence of coal mining in West Virginia in the 1990s (Fox, 1999).

The mining, grassland/shrubland, and forest classes had the most change during our study period (table 3). Mining nearly doubled in area from 1.7 percent of the ecoregion in 1973 to 3.2 percent in 2000.  Conversely, forest decreased from 86.6 percent to 83.3 percent (fig. 7). The grassland/shrubland category increased throughout the study period, as old mining areas transitioned back to forest.  Agriculture decreased slightly because of abandonment and subsequent conversion back to forest.  Developed lands increased slightly over the four time periods, in contrast to the population of the ecoregion, which has steadily decreased since the 1980s (fig. 8).

Figure 9 shows the net changes in land cover classes in the ecoregion over the study period.  The changes were relatively minor until the 1992 to 2000 period when there was resurgence in forest clearing for mining activities.  The leading land cover conversions were also all related to coal mining in the ecoregion.  Forest to mining was the top conversion during all time periods, ranging from 450 to 1,099 km2 (table 4).  During every time period, at least 65 percent of all changes were connected to mining activities in the ecoregion.

 

References

Fox, J., 1999, Mountaintop removal in West Virginia—an environmental sacrifice zone:  Organization and Environment, v. 12, no. 2, p. 163-183.

Omernik, J.M., 1987, Ecoregions of the conterminous United States: Annals of the Association of American Geographers, v. 77, no. 1, p. 118-125.

Raitz, K.B., and Ulack, R., 1984, Appalachia, a regional geography—land, people, and development: Boulder, Colo., Westview Press, 396 p.

U.S. Census Bureau, various years, at http://www.census.gov/prod/www/abs/decennial/index.htm.

Woods, A.J., Omernik, J.M., Brown, D.D., and Kiilsgaard, C.W., 1996, Level III and IV ecoregions of Pennsylvania and the Blue Ridge Mountains, the Ridge and Valley, and Central Appalachians of Virginia, West Virginia, and Maryland: EPA/600/R-96/077, U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Corvallis, Oreg., 50 p.

 

 

Table 1.  Amount of overall spatial change detected in ecoregion and proportion of ecoregion that experienced change during one or multiple time periods

 

 

Overall

Number of changes

 

spatial change

1

2

3

4

Percent of ecoregion

9.1

5.9

2.8

0.4

0.0

 

 

 

Table 2.  Raw estimates of percent change in ecoregion computed for each of four time periods and associated margin of error at 85-percent confidence level

 

 

Period

 

1973-1980

1980-1986

1986-1992

1992-2000

Total change (% of ecoregion)

2.9%

2.5%

3.3%

4.1%

Margin of error (85% confidence level)

+/-0.7%

+/-0.6%

+/-0.6%

+/-1.1%

Average annual rate of change (%/year)

0.4%

0.4%

0.6%

0.5%

 

 

 

Table 3.  Proportion of ecoregion covered by each land cover class during each of five mapped dates

 

 

1973

1980

1986

1992

2000

Net change 1973-2000

Land-use/land-cover class

km²

%

km²

%

km²

%

km²

%

km²

%

km²

%

Water

308

0.5

355

0.6

355

0.6

358

0.6

366

0.6

58

0.1

Developed

1834

3.1

1932

3.2

1956

3.3

2038

3.4

2156

3.6

322

0.5

Mechanically disturbed

177

0.3

152

0.3

177

0.3

182

0.3

220

0.4

43

0.1

Mining

1036

1.7

1079

1.8

1238

2.1

1178

2.0

1939

3.2

904

1.5

Barren

2

0.0

2

0.0

2

0.0

3

0.0

2

0.0

0

0.0

Forest

51724

86.6

51371

86.0

51069

85.5

50911

85.2

49768

83.3

-1956

-3.3

Grassland/Shrubland

317

0.5

524

0.9

631

1.1

841

1.4

1093

1.8

776

1.3

Agriculture

4188

7.0

4177

7.0

4162

7.0

4077

6.8

4043

6.8

-146

-0.2

Wetland

151

0.3

145

0.2

146

0.2

151

0.3

151

0.3

0

0.0

Non-mechanically disturbed

0

0.0

0

0.0

0

0.0

0

0.0

0

0.0

0

0.0

 

 

 


Table 4.  Leading land cover conversions during each of four time periods

 

 

 

 

Area changed

% of all

Period

From class

To class

(km2)

changes

1973-1980

Forest

Mining

539

31

 

Mining

Forest

427

24

 

Forest

Grassland/Shrubland

185

11

 

Forest

Mechanically disturbed

124

7

 

Mining

Grassland/Shrubland

76

4

 

Mechanically disturbed

Forest

61

3

 

Forest

Developed

60

3

 

Other classes

Other classes

279

16

 

 

 

1,751

100

 

 

 

 

 

1980-1986

Forest

Mining

450

31

 

Mining

Forest

188

13

 

Grassland/Shrubland

Forest

149

10

 

Forest

Mechanically disturbed

148

10

 

Mining

Grassland/Shrubland

121

8

 

Forest

Grassland/Shrubland

109

7

 

Mechanically disturbed

Forest

97

7

 

Other classes

Other classes

212

14

 

 

 

1,474

100

 

 

 

 

 

1986-1992

Forest

Mining

531

27

 

Mining

Forest

366

18

 

Mining

Grassland/Shrubland

242

12

 

Grassland/Shrubland

Forest

174

9

 

Forest

Mechanically disturbed

157

8

 

Forest

Grassland/Shrubland

130

7

 

Mechanically disturbed

Forest

106

5

 

Other classes

Other classes

289

15

 

 

 

1,995

100

 

 

 

 

 

1992-2000

Forest

Mining

1,099

45

 

Mining

Grassland/Shrubland

272

11

 

Forest

Mechanically disturbed

204

8

 

Forest

Grassland/Shrubland

189

8

 

Grassland/Shrubland

Forest

176

7

 

Mechanically disturbed

Forest

128

5

 

Mining

Forest

113

5

 

Other classes

Other classes

268

11

 

 

 

2,449

100

Overall:

 

 

 

 

1973-2000

Forest

Mining

2,620

34

 

Mining

Forest

1,094

14

 

Mining

Grassland/Shrubland

711

9

 

Forest

Mechanically disturbed

632

8

 

Forest

Grassland/Shrubland

612

8

 

Grassland/Shrubland

Forest

555

7

 

Mechanically disturbed

Forest

392

5

 

Other classes

Other classes

1,054

14

 

 

 

7,670

100

 

 

Refer to caption

 

Figure 1.  Central Appalachians and surrounding ecoregions.  The 32 randomly selected 100-km2 sample blocks are shown along with land use/land cover from the 1992 National Land Cover Dataset.

 

 

Refer to caption

 

Figure 2.  Forested hills of the Central Appalachians.

 

 

Refer to caption

 

Figure 3.  Processing coal at a coal mine in southern West Virginia.

 

 

Refer to caption

 

Figure 4.  Predominately forested area with agriculture in the valley.

 

 

Refer to caption

 

Figure 5.  The overall spatial change in all Eastern U.S. ecoregions.  Each bar chart shows the proportion of the ecoregion that experienced change on 1, 2, 3, or 4 dates.

 

 

Refer to caption

 

Figure 6.  The estimates of land cover change per time interval normalized to an annual rate of change as compared to other ecoregions. Central Appalachian ecoregion is highlighted in black.

 

 

Refer to caption

 

Figure 7.  Active logging of the ecoregion’s hardwood forests.

 

 

Refer to caption

 

Figure 8.  Central Appalachian population 1950 to 2000 (U.S. Census Bureau).

 

 

Refer to caption

 

Figure 9.  Per period net change for each land cover class. Areas above zero represent net gains for a land cover class, while areas below represent a net loss.

 

 

 



[1] U.S. Geological Survey, Center for Earth Resources Observation and Science, Sioux Falls, SD 57198

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