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Temperate deciduous forests

Trees and their wood make forests unique from other plant communities.  Forests inhabiting temperate regions of the world and dominated by trees that annually sensence their leaves (meaning they drop their leaves) are referred to as temperate deciduous forests. Here is a link to a time-lapse movie showing the annual cycling of a forest canopy. These occupy most of the eastern United States and are found in many other regions of the world.  This type of forest is dominated by broad-leaved deciduous species such as maples (Acer), oaks (Quercus), etc. as opposed to evergreen forests dominated by coniferous tree species like pines (Pinus). The varying colors in the picture to the right highlights the diversity of trees found in the Great Smokey Mountains National Park located in North Carolina and Tennessee.

Above is a deciduous forest near Bloomington, Indiana with large America beech trees visible (Fagus grandifolia).

A variety of types of temperate deciduous forest exist that are often descirbed based on the most dominant tree species. These types depend on geography and site factors such as soils and general moisture characteristics (dry vs. wet sites).  Temperate deciduous forests receive approximately 28 inches of rain per year to the north and 60 inches to the south which is usuaully distributed evenly throughout the year. Frost is common throughout the range of these forests. Forests are dynamic systems with continuous renewal.  The succession of forests is often complex. Natural forms of disturbance include fire, wind, diseases, and insect demage (link take you to other relevant content).  Over abundance of deer in some areas is also affecting these forests and altering their understory and forest regeneration.  Unlike grasslands which store most of the carbon that they fix via photosynthesis belowground, forests store immense quantites of carbon in woody biomass above ground.  Sustainable forestry practices help ensure maintenance of important ecosystem services (clean water [e.g. maintaining watersheds] and air), habitat for wildlife, and provide wood and paper products. The light enivornment in the understory is often dyanmic [click link to see sunflecks].

Above is a forest dominated by black cherry (Prunus serotina [click the link to see flowers of this tree]) in the Allegheny National Forest, Pennsylvania. The visible conifer is eastern hemlock (Tsuga canadensis). This National Forest is one of the most valuable in the United States because of the prevalence of black cherry, a valuable hardwood species used to make cabinents and furniture. The understory is dominated by eastern hayscented fern (Dennstaedtia punctilobula).

To the left is a picture of squaw root or American cancer-root (Conopholis americana), a parasitic plant. These cones like structures are actually flowers that emerge up from the ground. Most of the growing season it is hidden belowground where it secretely parasitizes the roots of oak (Quercus) and beech (Fagus) trees. Here is a link to information on another parasitic plant.

The other three pictures are from the Great Smokey Mountains National Park. They are a reminder of how forests help provide important ecosystem services like clean water and are habitats to a diversity of creatures including milipedes and mushrooms. Click on the link to see a time-lapse sequence of a mushroom growing.