An idea or course of action which will lead to something wrong. Or if you mean a literal slippery slope then ice ig lol
Answer: Human activities are transporting pathogens into new habitats (or communities) at an unprecedented rate.
Explanation:
When pathogens are introduced into a new population in a community, most individuals have not develop resistance to that pathogen thus it will be more virulent.
A very thin ring in a tree would indicate that there was little or no water in the area