Silty Floodplain Forest

Description

The historical reference state for this ecological site was old growth floodplain forest. The forest was dominated by American sycamore, ashes and elms. Eastern black walnut was a common component. Maximum tree age was likely 150 to 300 years. Periodic disturbances from flooding, wind or ice maintained the open, uneven structure and 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 very rare today. Altered drainage has resulted in increased canopy density, which has affected the abundance and diversity of ground flora. Most former reference states are currently altered because of timber harvesting, clearing and conversion to grassland or cropland.

Dominant plant species

1. American sycamore (Platanus occidentalis), tree

2. black walnut (Juglans nigra), tree

3. slippery elm (Ulmus rubra), shrub

4. Virginia wildrye (Elymus virginicus), grass

5. smallspike false nettle (Boehmeria cylindrica), grass

Submodel

Description

Composition is altered from the reference state depending on tree selection during harvest. This state will slowly increase in more shade tolerant species with selective harvesting techniques. Without periodic canopy disturbance, stem densities and more shade tolerant species will increase in abundance. Some periodic uncontrolled grazing may be occurring.

Dominant plant species

1. silver maple (Acer saccharinum), tree

2. elm (Ulmus), tree

3. American sycamore (Platanus occidentalis), tree

4. roughleaf dogwood (Cornus drummondii), shrub

5. sedge (Carex), grass

Submodel

Description

Conversion of other states to non-native cool season species such as tall fescue (Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.), red top (Agrostis alba auct. non L.) and white clover (Trifolium repens L.) has been common. Occasionally, these pastures will have scattered pecans. Long term uncontrolled grazing can cause significant soil erosion and compaction. A return to the reference state may be impossible, requiring a very long term series of management options and transitions.

Dominant plant species

1. tall fescue (Schedonorus arundinaceus), grass

2. white clover (Trifolium repens), grass

Submodel

Description

This is a state that exists currently with intensive cropping of corn (Zea mays L), soybeans (Glycine max (L.) Merr.), and wheat (Triticum aestivum L.). Some conversion to cool season hay land occurs, but when commodity prices are high, these states transition back to cropland.

Dominant plant species

1. corn (Zea mays), grass

2. wheat (Triticum), grass

3. soybean (Glycine max), grass

Submodel