Answer:
The factors can be sorted into two categories - biotic (living organisms) and abiotic (nonliving organisms).
An example of a biotic factor is invasive species (organisms non-native to that area). These species do harm to the environment it is in as it is not originally part of the community. A specific example of an invasive species are domesticated cats - they kill a lot of birds and organisms that have always been there, seeing a decline in the population of these organisms.
Abiotic factors include human activities such as deforestation, pollution; and natural factors such as natural disasters (floods, etc). These can wipe out whole ecosystems, kill off whole species, etc.
Hope this helps and is specific enough to give you some guidance!