What is the type of conservation in which seed banks are an example? Firstly I think this question is quite ambiguous (I did not come up with it) so sorry. I have only come across 4 'types' of conservation: environmental, animal, marine, and human conservation. I am aware that animal conservation includes their habitats, so perhaps keeping seed banks is a way of preserving habitats. I may generally say that seed banks are a way of preserving biodiversity but I don't know if 'biodiversity conservation' is even a thing.

Seed banks are a part of "plant conservation" efforts which is missing from your list.