| A unit of Lasting Forests
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A Total Forest Management Plan
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This section deals with the vegetative regions and cover types in which the land ownership is located.
It is very hard to decide where one classification system and another starts. There is much overlap as well as mixture of purposes. Some overlap is likely. Some classification systems, however, have been created in an attempt to achieve notability and priority for the agency which creates it. Practicality, universality, or discriminatory power may not have been as dominant criteria as they might have been. Perhaps priority (where and by whom first created), other things being equal, was not considered as strongly as is done in other areas of biology.
Fink and Elder (1982:1) give the elements of Bailey's ecoregion approach (Table 1). Bailey's regional criteria were developed for general purpose use, largely by natural resource disciplines. Delineation was based on climate, vegetation, geology, and soils. In the upper more general levels, climate is most influential. In the lower levels, soil is dominant. At the ninth (or site) level, soil phase (e.g., a series split as a function of slope) is the characteristic forcing an area into a category. Fink and Elder (1982:1) claimed that the hierarchial nature of the classification may allow managers ". . . to extrapolate the result of land management practices applied to an area into other areas classified as the same ecoregion."
It will be noted though that, intuitively, the ability to do this is greatest in the mid levels. The classes give a way to aggregate data, but the issue is: for what purpose? Aggregation leading to statistics -- the transformation of data into information, and it is the chief reason for all of this classification activity. The upper levels are said to be useful in land management decision making and planning at regional and national levels, perhaps in assessing growth potentials and investments required to achieve reasonable resource production.
Increasingly, GIS capabilities reduce the needs for grouping and searching for similarities and expand our abilities to deal with differences, treat each area as unique, and utilize knowledge of time or age (rarely evident in the single map "snapshot") as a dominant factor on the lanscape. The following has been useful to some people and it is repeated for them and for comparative purposes. Sample information for an area is presented to suggest the pattern for other areas.
The ecoregion nomenclature and numerical code is based on Fink and Elder (1982). The code is 22l404Csa and is based on the following:
1. Humid Temperate Domain - 2000
4-12 months when the average temperature is above l0 degrees C and a coldest month is under 18 degrees C.
2. Hot Continental Division (Dfa) - 2200
Cold winters and hot summers; average temperature in coldest month is below 0 degrees C and above 22 degrees C in warmest month; maximum precipitation in the summer; soils chiefly alfisols (gray-brown-podzolic); deciduous forests with weakly developed understories.
3.Eastern Deciduous Forest Province - 2210
Portion of division with a uniform regional climate which corresponds to a broad vegetation region and group of zonal soils; vegetation regions correspond to climax communities that are uniform in dominant plant species.
4. Appalachian Oak Forest Section - 2214
5. Open Low Mountains District - 2214 11 C5a
A part of a Section having uniform geomorphology at the level of Hammond's (1964) land-surface form regions; perhaps equivalent to physiographic regions.
District Quantifiers
C - 20-50% of area gently sloping
5 - 1000 to 3000 ft local relief (i.e., maximum difference in elevation within an area that is 6 miles (9.6 km) across)
a - more than 75% of gentle slope is in lowland (i.e., lower half of local relief)
6- Appalachian Sandstone Capped Ridges Land Type Association - 2214 11 C5aj. Association descriptors are based on Fink and Elder (1982:35)
Geomorphic Setting
This area consists of high ridges that run parallel in a northeast to southwest direction. These mountain ridges have narrow, straight crests and long, steep, somewhat dissected slopes. The elevations of the crests are mostlyy between 2,000 and 4,000 feet, but some of the highest points in the northern part are as high as 4,500 feet (1370m)
Climate
The climate is moist and cool; average annual precipitation is around 40 to 50 inches and average annual temperature is above 53 degrees F to 57 degrees F (12 - 14 degrees C). Both precipiation and temperature vary with elevation. The average freeze-free period ranges from 150 to 190 days.
Geology
The mountain ridges are capped with sandstone. Shales underlie the lower slopes and foothills.
Hydrology
Numerous small perennial streams and springs are located in the narrow valleys and deep hollows. These, along with fairly well-distributed rainfall, furnish an adequate supply of water to the area.
Soils
The soils on the upper slopes are shallow to rock, acid, low in fertility, and most commonly stony on the lower slopes. In coves where downslope creep has accumulated the soils, they are deep, loamy, and productive for trees. Soils suitable for cultivation make up a minor acreage and are located in small tracts on benches and along drainageways.
Land Use/Land Cover
Most of the area is in mixed hardwood and pine forest. Small part-time farming occurs in the narrow valleys.
Cover has been discussed. This is a special unit that provides the reader with the cover type of the large area within which the owner ship is located. The cover type, designated C, is a factor to be used in universal soil loss equations (with revisions). The latest Landsat or other area images are used (unsupervised analyses with limited ground checks used to name the cover types) to get USGS level 2 land-use cover type. A file of translations of the named type to the variable C of the equation are being developed.
A report of net change in types by county is intended, and repeated every 3-5 years. The information is perceived to be useful in interpreting yields of crop and livestock in counties, evaluating the scope of government aids and subsidies, and the cost-effective assignment of agents to areas where needs are highest. The data can be sued to assess changing risks of floods (e.g., as more or less land is in cropland or forests) as well as to project changes in gross-state-product (GPS) as influenced by the farm and forestry sector of the economy.
Eventually models can be created that will allow some projections to be made. These are likely to contribute to local as well as state planning efforts.
Rates of revegetation of surface-mined lands may be of interest at both the state and federal levels.
Forest Type Groups and percent coverage data of the US are available at http://www.srsfia.usfs.msstate.edu
See (under development) Forest Cover Types of Virginia
References Cooke, W.H. 2001. Development of a methodology for predicting forest area for large-area resource monitoring. USDA For Servive Southern Res. Station, Ashville, NC Research Paper SRS-24, 11p.
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Last revision January 17, 2000.