Central Appalachians

By Kristi L. Sayler ¹

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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

 

 

 

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.

 

 

 

Figure 2.  Forested hills of the Central Appalachians.

 

 

 

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

 

 

 

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

 

 

 

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.

 

 

 

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.

 

 

 

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

 

 

 

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

 

 

 

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.