Wet Acidic Sandy Flatwoods

Description

Prior to European-American settlement of the area, about 49 percent of the vegetation was dominated by very shade tolerant species such as hemlock (Tsuga canadensis) (phase 1.2) and about 28 percent was dominated by red maple (Acer rubrum) and other swamp hardwoods (phase 1.1) (Albert, et al., 1995). Hemlock does not occur naturally in northern Indiana (Kartesz, 2013; Swink & Wilhelm, 1994), so there phase 1.2 would have included only yellow birch (Betula alleghaniensis). Because forests are still recovering from past logging, most forests today are intermediate in succession as phase 1.1. Canopy dominants range from red maple to pin oak with varying amounts of black gum (Nyssa sylvatica) and swamp white oak (Quercus bicolor). Although usually not abundant in this region, black gum is a reliable indicator of acidic sites like these. Pin oak (Quercus palustris) is found throughout the range of this site concept, but is less prevalent to absent in stands north of Ottawa County. Acid tolerant ferns (e.g. cinnamon fern, Osmundastrum cinnamomeum; Virginia chain fern, Woodwardia virginica) are found in the understory. Most of the frequent understory shrubs (e.g. blueberries, swamp dewberry – Rubus hispidus) and forbs (e.g. partridge berry, Mitchella repens; Canada mayflower, Maianthemum canadense) are found almost exclusively on hummocks, whereas the low wet ponded portions are nearly bare of vegetation depending on shade levels. Peat moss (Sphagnum spp.) is common in zones that remain saturated for long periods, but which are only shallowly ponded. Otherwise, buttonbush (Cephalanthus occidentalis) and lizard’s tail (Saururus cernuus) are frequent constituents where ponding has precluded other species. Sites that are ponded for longer durations may lack canopy altogether and give way to wet-mesic prairie or coastal plain marsh.

Because wet acidic sands are relative outliers in a region otherwise dominated by calcareous tills, many species occur here that are disjuncts from their main ranges in unglaciated areas to the south (e.g. Rhynchospora macrostachya). Several species are disjuncts from the Gulf and Atlantic Coastal Plains where they are found in similarly acidic sandy sites (Reznicek, 1994; Sorrie & Weakley, 2001).

Submodel

Description

The Agriculture State accommodates the 49 percent of the sites that are actively managed, or are recovering from agriculture. This is a heterogeneous assemblage addressed here collectively. Included within the 49 percent is 31 percent of the area considered agriculture and 17 percent that is developed at low to high intensities (e.g. cities) (U.S. Department of the Interior, Geological Survey, 2011).

Submodel