Physiognomy and Structure: No Data Available

Floristics: The typical stand structure of this community type consists of a tall, closed overstory, with very open understory tree layers, and a variably dense shrub layer. The overstory of most stands is dominated or codominated by tall, straight Liriodendron tulipifera often exceeding 35 m in height. Fraxinus americana and Quercus rubra are the most frequent overstory associates and often codominate. Less frequent overstory associates that can sometimes codominate in discrete areas include Quercus alba, Quercus montana (= Quercus prinus), Carya ovalis, Carya tomentosa (= Carya alba), Carya cordiformis, Ulmus rubra, Nyssa sylvatica, Fagus grandifolia, and Juglans nigra. Subcanopy tree layers contain representatives of the overstory species and Acer rubrum. The lowest tree and shrub layers usually contain small to large colonies of Asimina triloba and Lindera benzoin, along with Cercis canadensis and Cornus florida. More locally important small trees and shrubs include Carpinus caroliniana and Hamamelis virginiana. High-climbing vines of Parthenocissus quinquefolia, Toxicodendron radicans, and Vitis spp. are common. The herb layer is usually lush and dense, except where boulder streams prevail or deer grazing is severe. Patch-dominance of ferns and leafy forbs is characteristic; species achieving local abundance in the type include Adiantum pedatum, Amphicarpaea bracteata, Arisaema triphyllum, Asarum canadense, Actaea racemosa (= Cimicifuga racemosa), Deparia acrostichoides, Hydrastis canadensis, Phegopteris hexagonoptera, Polystichum acrostichoides, and Uvularia perfoliata. The most constant, low-cover herbs in 22 Virginia and Maryland plots of the type are Botrychium virginianum, Circaea lutetiana ssp. canadensis, Desmodium nudiflorum, Galium circaezans, Galium triflorum, Maianthemum racemosum ssp. racemosum, Phryma leptostachya, Sanguinaria canadensis, and Sanicula canadensis. Additional characteristic herbs include Carex laxiflora var. laxiflora, Collinsonia canadensis, Cypripedium parviflorum var. pubescens, Galearis spectabilis, Hepatica nobilis var. obtusa, Podophyllum peltatum, and Stellaria pubera.

Dynamics:  Sites now supporting this community are some of the most productive in the Mid-Atlantic region, and most were cleared or cut over in the past. Dominance of Liriodendron tulipifera in stands is no doubt indicative of establishment following abandonment of fields, logging, and natural, large-scale forest disturbances. The ability of Liriodendron to opportunistically occupy and outgrow competitors in gaps created by windthrow and other disturbances apparently enables this species to maintain a position in older-aged mixed forests (Orwig and Abrams 1994, Busing 1995). Although many stands representing this community have probably reached an intermediate successional stage (70 to 140 years old) and become more mixed than a typical, early-successional forest dominated by Liriodendron tulipifera, their future development is unclear. Most plots contain Quercus rubra or Quercus alba in the overstory, but recruitment of these oaks is very low. The most numerous potential canopy species now present in the understory are hickories (Carya tomentosa, Carya cordiformis, and Carya ovalis), Fraxinus americana, and Nyssa sylvatica. In the absence of longer-lived and more tolerant species such as Fagus grandifolia or Acer saccharum (usually unimportant or absent in the type), it appears that maturing stands will gradually contain more mixed dominance by Liriodendron, Carya spp., Fraxinus, and perhaps Nyssa, with fewer Quercus spp. Most likely because of their moist fertile soils, habitats of this community type are very favorable for shade-tolerant, invasive introduced plants, particularly following small-scale soil disturbances. The most problematic introduced species include Microstegium vimineum, Rubus phoenicolasius, Lonicera japonica, and Alliaria petiolata. Mortality or partial die-back of Cornus florida resulting from the fungal pathogen dogwood anthracnose (Discula destructiva) and visible damage to herbaceous plants by grazing white-tailed deer have been noted in many stands of the type.