“Succession” describes the changes a community of plants undergoes over time. In most cases, plant communities change from a short lived, transitory grouping to a more permanent collection of plants. This may take a few short years, or it could take decades, depending on a number of variables.
To visualize this, think about a large, grassy lawn. Regular mowing and some weeding are necessary to maintain this grass community. Let’s say, however, that you discontinued mowing this site. The grasses will continue to grow, then “weeds” like pigweed, smart weed, sorrel, clover, goldenrod, honeysuckle, and poison ivy will begin to grow amongst the grasses. If the area in this example is not mowed for a season or two, the plant community will change from a lawn to a field or meadow, which is a different ecological community. Suppose that this meadow is allowed to continue to develop: in time, longer-lived, herbaceous and woody perennial plants, such as mullein, Queen Anne’s lace, ragweed, pokeweed, brambles, eastern red cedar, dogwood, sumac, hawthorns, locust, and cherry will begin to invade the area. These more advanced meadows are often called “old fields.” As the young trees and shrubs are allowed to grow, the old field becomes an old field in the shrub-sapling stage. This means that the meadow now has scattered trees and shrubs growing in it. After more time, the trees and shrubs grow larger, and more woody vegetation invades the field, the canopies beginning to close together. Once “canopy closure” begins, the grasses and field vegetation are covered in the shade of the canopy and begin to die out.