Moist Acidic Sandy Flatwoods

Description

Prior to European-American settlement of the area, about 70 percent of the vegetation was dominated by very shade-tolerant species such as beech (Fagus grandifolia) and hemlock (Tsuga canadensis) (phase 1.2) and about 28 percent was dominated by a mix of white pine (Pinus strobus), oaks (Quercus spp.), and other hardwoods (phase 1.1; Albert, et al., 1995). Hemlock does not occur in northern Indiana, so there phase 1.2 was characterized by beech only. Because forests are still recovering from past logging, most forests today are intermediate in succession as phase 1.1. Red maple (Acer rubrum) overwhelmingly dominates the canopy, but beech can be found in high numbers in the understory, supporting the contention that future stands will naturally succeed to phase 1.2 beech-dominated forests. The most frequent canopy associates are red oak and black gum. Although usually not abundant in this region, black gum (Nyssa sylvatica) is a reliable indicator of acidic sites like these. Acid tolerant shrubs (e.g. blueberries, Vaccinium spp.; swamp or bristly dewberry, Rubus hispidus), forbs (e.g. partridge berry, Mitchella repens; Indian cucumber, Medeola virginiana), and ferns (e.g. cinnamon fern, Osmundastrum cinnamomeum; New York fern, Parathelypteris noveboracensis) are found in the understory. Disturbance from canopy openings or fire, favors species such as sassafras (Sassafras albidum), bracken fern (Pteridium aquilinum) and greenbrier (Smilax rotundifolia). On occasion, larger openings may allow for establishment of big tooth aspen (Populus grandidentata) (phase 1.3). Historically, these small gaps would have been too small to be mappable using General Land Office survey notes.

The fire return intervals for the reference state range from greater than 1,000 years for a northern hardwoods-hemlock dominated system to crown fires about every 290 years with understory fires every 70 years for a pine-oak dominated system (U.S. Department of the Interior, Geological Survey, 2008).

Submodel

Description

The Agriculture State accommodates the 46 percent of the sites that are actively cultivated, or are recovering from agriculture. This is a heterogeneous assemblage addressed here collectively. Included within the 46 percent is 20 percent of the area considered agriculture, 9 percent is managed vegetation, including tree plantations, and 18 percent is developed at low to high intensities (e.g. cities).

Submodel