Upland Woodland

Description

These woodland communities were influenced by fire, drought, and wind. Herbivory by native (now expatriated) ungulates also played a role. There are two phases associated with this reference state. The overstory in the first phase was dominated by white oak and shagbark hickory, with scattered other oaks and hickories. Fire frequency was probably every 5 to 15 years. Fire, drought and natural native grazing would have maintained a more open canopy and abundant ground flora species. This second phase was also a woodland, but with a more closed canopy. It is characterized by an increase in understory saplings and shrubs. The herbaceous layer is diminished. Fire-free intervals probably exceeded 15 years.

Submodel

Description

Most existing current alternative areas of Upland Woodlands have experienced fire exclusion for decades along with periodic uncontrolled domestic livestock grazing. In the absence of fire, ongoing recruitment of trees into the canopy develops a closed canopy, shading out the herbaceous ground flora. Black oak, hickory and midstory species increase. Herbaceous cover and diversity greatly diminishes, leaf litter builds up, and more shade-tolerant species persist, such as elmleaf goldenrod (Solidago ulmifolia Muhl. ex Willd.) panic grass (Dichanthelium dichotomum (L.) Gould) and late purple aster (Symphyotrichum patens (Aiton) G.L. Nesom). The understory also changes with ironwood, sassafras (Sassafras albidum (Nutt.) Nees) and black cherry (Prunus serotina Ehrh.) saplings. Many areas that have experienced long term uncontrolled grazing have significant soil erosion and compaction issues along with tree damage and introduction of invasive species. Transition to cool season grasslands (State 3) or intensive cropland (State 4) is common.

Description

Conversion of other states to non-native cool season species such as tall fescue (Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.) and red clover (Trifolium pratense L.) has been common in the Illinois Central Claypan area. Occasionally, these pastures may have scattered mature oaks. 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.

Description

This is a state that exists currently on slopes less than 10 percent with intensive cropping of corn (Zea mays L.), soybeans (Glycine max (L.) Merr.), and winter wheat (Triticum aestivum L.) occurring. Some conversion to cool season grassland occurs for a limited period of time before transitioning back to cropland.