All of the following are threats to biodiversity except species preservation. Biodiversity refers to the different variety of life that inhabit an ecosystem. Species preservation is the act or process of preserving organisms that live in an ecosystem. In a way it is preventing the further destruction or decay of a particular species that are dwindling in numbers. Human activities (e.g. hunting, habitat destruction) are the biggest threat to biodiversity, but the irony of it all is that humans are also responsible for the protection and preservation of these species.