Within each ecological succession (primary and secondary), there are transitional stages as the plant community moves toward a climax or stable community. Each stage of ecological succession is called a seral community, or sere.
(Click to enlarge.)
This image shows different seral stages (seres) in a forest ecosystem beginning with the pioneer species of plants on the left and ending with the mature trees on the right. The seral stages are called early seral, mid seral, and late seral.
A forest stand is a continuous community of trees that has a common set of characteristics. Forest stands develop in several structural stages. A structural stage describes the size and the arrangement of the different trees and tree parts.
Stand development begins with a disturbance. This major event causes changes in the structure and composition of a forest; this is called a stand-replacing disturbance. The first structural stage of forest succession begins after this disturbance. Read each row of the table below for a description of forest structural stages.
| Establishment | This stage is also called stand initiation. This is the first stage of forest succession following a stand-replacing disturbance. In this phase a population of vegetation is established. |
| Thinning | This stage is also called stem-exclusion. During this phase, trees grow higher and enlarge their canopy, competing with their neighbors for sunlight and moisture. Eventually the canopies of neighboring trees touch each other and lower the amount of sunlight available to understory plants. |
| Transition | This stage is also called the understory-reinitiation phase. During this time, overstory trees begin to die and regrowth of understory vegetation occurs. |
| Shifting Mosaic | This stage is also called the old-growth stage. By now, three or more tree layers of vegetation have become established. This stage is described as a stable, steady state, or climax. |
Question
What is the relationship between a sere and a structural stage?
