Not too easy. Not too difficult.
I recommend this course, for it will give you answers to questions that have relations as to how and where such a biological process is rooted.
The idea of ecological succession, and that environmental disturbances is rather healthy for the ecosystem, since it will aid the increase of the earth's biodiversity.
Hours per week:
Advice for students:
Listen attentively to your teacher and never be afraid to ask for help.