Seasonally Dry Floodplains

Description

Reference State is a Mesic to Wet-mesic mixed deciduous forest. Tree species composition and age structure vary in space and time. Principal deciduous species are red maple (Acer rubrum) and sugar maple (A.Saccharum). Less common associates are basswood (Tilia americana), white ash (Fraxinus americana), or black ash (F. nigra). In some stands scattered old specimens of trembling aspen (Populus tremuloides), or white birch (Betula papyriphera) are present. There often is an admixture of conifers, most commonly balsam fir (Abies balsamea) and White spruce (Picea glauca), especially in the seedling and sapling layers. White pine (P. strobus) has also been a component historically, and old white pine tree stumps, as well as sporadic old trees can be found in today’s communities. In the absence of catastrophic disturbances this mixture of species is maintained by regeneration in canopy gaps, resulting from natural mortality and small-scale blow-downs.

For additional description, including shrub and herb layers see “Ecological Site Concept” above.

Submodel

Description

Aspen and paper birch have a very narrow window of environmental and ecological conditions for successful establishment. Main requirements are exposed mineral soil and elimination, most effectively by fire, of on site seed sources of potential competing vegetation. In addition, continual adequate soil moisture must be available for initial seedling development. Once seedlings are firmly established height growth of both species is relatively rapid and able to outgrow most of competing species. Paper birch seedlings and saplings tolerate partial shade and often become members of mixed species communities. This is not true for aspen, which requires continuous full-sun exposure for survival. Aspen stands are initially very dense due to sprouting from extensive lateral roots, but rapid natural thinning ensues as stems compete for available light.

Submodel

Description

Cultivation of agricultural crops. In this region most often hay production.

Submodel