What type of stands usually occur after natural disturbances or clearcutting?

Even-aged stands typically occur after natural disturbances or clearcutting because these practices lead to a homogeneous age structure among the trees in a given area. When a natural event, such as a wildfire, storm, or insect infestation occurs, it often removes a large portion of the existing tree population, creating an opportunity for new growth. Clearcutting, which involves removing all or most trees in a certain area, also results in the same effect where the upcoming trees are mostly of the same age as they all grow back during the same regeneration period.

In both situations, the result is a forest where the trees are relatively uniform in age since they either sprout from existing root systems or are planted contemporaneously. This contrasts with uneven-aged stands, which consist of trees of various ages and sizes, commonly found in forests that have not experienced such uniform disturbances. Multi-aged stands incorporate trees of different age classes as a result of selective logging or natural regeneration over time, while shelterwood systems involve progressively removing trees to encourage the growth of new trees, leading to a mix of age classes rather than an even-aged structure.

Thus, the occurrence of even-aged stands is a direct consequence of disturbances or intentional clearcutting, making this answer the most accurate in relation to