Characteristics:

• Intolerant of shading, fast-growing, short-lived, too small to maintain overstory (cliffs, forest edge, fence rows).
• Naturally maintained by fire or thin soil.
• Artificially maintained through old field succession (cropland reversion to forest, including fence rows).
• Examples:

  Eastern red cedar (Juniperus virginiana)

  American plum (Prunus americana)

  Hawthorn (Crataegus sp.)

  Box elder (Acer negundo)

  Siberian elm (Ulmus pumila)

  Smooth sumac (Rhus glabra)

  White mulberry (Morus alba)