Science Question for Saturday, February 13th, 2016

Abandoned cornfields have been the sites of investigations concerning ecological succession, the orderly progression of changes in the plant and/or animal life of an area over time (see Figure 1).

(Note: The plants are ordered according to their appearance during ecological succession.)

During the early stages of succession, the principal community (living unit) that dominates is the pioneer community. Pioneer plants are depicted in Figure 2.

The final stage of ecological succession is characterized by the presence of the climax community, the oak-hickory forest. Figure 3 depicts the gradual change from pine to hardwoods.

Figures adapted from Eugene P. Odum, Fundamentals of Ecology. ©1971 by Saunders College Publishing/Holt, Rinehart, and Winston, Inc.

According to the information in Figure 3, a 150-year-old climax community would contain oak and hickory trees with a density of approximately:

  • F. 3,000 trees per unit area.
  • G. 5,000 trees per unit area.
  • H. 15,000 trees per unit area.
  • J. 20,000 trees per unit area.