Loamy Sinkhole Woodland

Description

The historical reference state for this ecological site was dominated by black oak, post oak and white oak. Periodic disturbances from fire, wind or ice maintained the woodland structure and diverse ground flora species. Long disturbance-free periods allowed an increase in both the density of trees and the abundance of shade tolerant species. Two community phases are recognized in the reference state, with shifts between phases based on disturbance frequency.

Reference states are rare today. Many sites have been converted to grassland. Others have been subject to repeated, high-graded timber harvest coupled with domestic livestock grazing. Fire suppression has resulted in increased canopy density, which has affected the abundance and diversity of ground flora. Many sites have been managed effectively for timber harvest, resulting in managed woodlands.

Submodel

Description

These woodlands tend to be rather dense, with a low diversity understory and ground flora. Composition is also likely altered from the reference state depending on tree selection during harvest. Thinning can increase overall tree vigor and improve understory diversity. However, in the absence of fire, the diversity and cover of the ground flora is still diminished. Continual proper timber management, depending on the practices used, will maintain this state. Without periodic disturbance, stem density and fire intolerant species, like hickory, increase in abundance.

Submodel

Description

Conversion of woodlands to planted, non-native cool season grassland species such as tall fescue is common for this region. Surface fragments, low organic matter contents and soil acidity make grasslands harder to maintain in a healthy, productive state on this ecological site.

Two community phases are recognized in the grassland state, with shifts between phases based on types of management. Poor management will result in a shift to Community 3.2 that shows an increase in oak sprouting and increases in broomsedge densities.

Submodel

Description

States that were subjected to repeated, high-grading timber harvests and uncontrolled domestic grazing transitioned to a High-Graded Grazed Woodland state. This state exhibits an over-abundance of hickory and other less desirable tree species, and weedy understory species such as coralberry, gooseberry, poison ivy and Virginia creeper. The existing vegetation offers little nutritional value for cattle, and excessive cattle stocking damages tree boles, degrades understory species composition and results in soil compaction and accelerated erosion and runoff. Two common transitions from this state are woody clearing and conversion to State 3, grassland or removing livestock, limited harvesting, and allowing long term succession to occur to some other woodland state.

Submodel