Gravelly Protected Backslope Forest

Description

The historical reference state for this Ecological Site was old growth oak forest.
The Old Growth Forest was dominated by white oak. Maximum tree age was likely 150-300 years. Periodic disturbances from fire, wind or ice maintained the dominance of white oak by opening up the canopy and allowing more light for white oak reproduction. Long disturbance-free periods allowed an increase in more shade tolerant species. Two community phases are recognized in the Old Growth Forest state, with shifts between phases based on disturbance frequency.
Old Growth Forests are very rare today. Many sites have been converted to non-native pasture (State #5). Others have been subject to repeated, high-graded timber harvest coupled with domestic livestock grazing (State #6). Fire suppression has resulted in increased canopy density, which has affected the abundance and diversity of ground flora. Many Old Growth Forests have been managed effectively for timber harvest, resulting in either even-age (State 2) or uneven-age (State 3) forests.

Submodel

Description

This state starts with a sequence of early seral white oak forests, which mature over time. These forests tend to be rather dense, with a depauperate understory and ground flora. Thinning can increase overall tree vigor and improve understory diversity. Continual timber management, depending on the practices used, will either maintain this state, or convert the site to uneven-age (State 3) woodlands. Prescribed fire without extensive timber harvest will, over time, cause a transition to Managed Oak Woodlands (state 4).

Submodel

Description

Uneven-Age Managed forests resemble their Reference State (Old Growth Forests). The biggest difference is tree age, most being only 50-90 years old. Composition is also likely altered from the reference state depending on tree selection during harvest. In addition, without a regular 15-20 year harvest re-entry into these stands, they will slowly increase in more shade tolerant species and white oak will become less dominant.

Submodel

Description

The Managed Oak Woodland State results from managing forest communities on protected aspects in States 1, 2 or 3 with prescribed fire, over time. This condition likely existed historically during extremely droughty times. However, woodland management on protected slopes will be challenging because of the productivity of the tree species on these sites. While inclusion of protected aspects in a woodland management unit is acceptable, singling out these historically forested sites for woodland management is undesirable.

Submodel

Description

Type conversion of forests to planted, non-native pasture species such as tall fescue has been common in this area. Steep slopes, abundant surface fragments, low organic matter contents and soil acidity make non-native pastures difficult to maintain in a healthy, productive state on this ecological site. If grazing and active pasture management are discontinued, the site will eventually transition to State 2 (Even-Age). Timber Stand Improvement practices can hasten this process.

Submodel

Description

Timbered sites subjected to repeated, high-graded timber harvests and domestic grazing transition to this State. This state exhibits an over-abundance of hickory and other less desirable tree species, and weedy understory species such as buckbrush, gooseberry, poison ivy and Virginia creeper. The vegetation offers little nutritional value for cattle, and excessive stocking damages tree boles, degrades understory species composition and results in soil compaction and accelerated erosion and runoff. Exclusion of cattle from sites in this state coupled with uneven-age management techniques will cause a transition to State 3 (Uneven-Age).

Submodel