Nearctic Temperate Deciduous Forest - Code: Ne3B

South of the taiga (or boreal) zone, this is the most widespread habitat in the e. Nearctic and familiar to almost everyone who has spent time outdoors east of the Mississippi River. Vast broadleaf forests have historically blanketed the e. Nearctic, and many large swaths of forest are still intact. The Nearctic temperate deciduous forest experiences distinct seasons with cold winters, hot and humid summers, and significant rainfall. Winter lows vary from 30°F to ⎻15°F (⎻1 to ⎻26°C), while summer highs are in the range of 80–95°F (27–35°C). Precipitation falls consistently year-round as either rain or snow and totals 30–60 in. (750–1,500mm). 
Nearctic temperate deciduous forest typically has a closed canopy and well-developed mid-story, shrub layer, and understory. The canopy height is typically 50–80 ft. (15–25m), the trees closely spaced. The understory and shrub layer can be quite thick and difficult to navigate off trails, except in rare old-growth stands. During much of spring and early summer, the ground can be flooded or dotted with ephemeral pools. Thankfully, nature reserves in this habitat are well developed and plentiful, and extensive trail networks make exploring the habitat quite easy.
This forest has a high diversity of canopy trees compared to other Nearctic habitats, and species composition varies throughout the range. In general this forest is dominated by a wide range of oak (Quercus spp.), hickory (Carya spp.) species, especially in drier, more westerly forests and south-facing slopes. Wetter forests and those on cooler north-facing slopes predominantly consist of maples (Acer spp.), American Beech (Fagus grandifolia), American basswood (Tilia americana), and ashes (Fraxinus spp.). Tulip-tree (Liriodendron tulipifera) is common throughout. American Chestnut (Castanea dentata) was a major part of this habitat but is functionally extinct. Historically there were regular, low-intensity fires in this habitat that favor oaks and hickories. Fire suppression over the last century has resulted in a shift towards more mesic, shade-loving species.

Early Successional Temperate Deciduous Forest is a distinct subtype with its own set of flora and fauna. This subtype occurs in areas that have been recently cleared, including regenerating pastures, powerline cuts, windfalls and forest edges. This subtype generally includes saplings from the surrounding forest as well as a wide variety of low dense shrubs. Common shrubs in this habitat include dogwoods (Cornus spp.), persimmon (Diospyros spp.), blackberries (Rubrus spp.), Black locust (Robinia pseudoacacia), sumac (Sumac spp.), and Sassafras (Sassafras albidum) along with the highly invasive White Honeysuckle (Lonicera japonica). Often, many of the small eastern subtypes of Tallgrass Prairie will progress to this habitat before turning into mature Nearctic Temperate Deciduous Forest. 

Eastern Riparian Woodland is another distinct subtype found along waterways and in floodplains within Nearctic Temperate Deciduous Forest and extending into Nearctic Temperate Mixed Forest. This forest is occasionally flooded though generally not for extended periods of time. American Sycamore (Platanus occidentalis), Silver Maple (Acer saccharinum), Sugarberry (Celtis laevigata), Green Ash (Fraxinus pennsylvanica), and Sweetgum (Liquidambar styraciflua) are all typical trees here - especially the sycamores. The forest here is often very tall with many dead snags and stands of dead trees after extensive flooding. The understory is quite shrubby, especially in heavily disturbed areas of the floodplain, and often dominated by willows (Salix spp.). Herbaceous understories consisting mostly of Spotted Jewelweed (Impatiens capensis) are also a regular feature in this subtype.