If an ecosystem undergoes changes, does the community of its Organisms change?

If an ecosystem undergoes changes, then the community of its organisms also changes. For example: if under the canopy of a birch forest spruces appear that love shading, then when they grow higher than birches, birches die from lack of light and a spruce forest forms in place of a birch forest.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.