I consider that the main threats to diversity are monocropping, which impoverish our patrimony, and Patents on Vegetal Varieties that lead to Biopiracy.

Genetic diversity regenerates ecosystems and avoids pandemic fleas.
For this it must be utilized, not capitalized.
Global seed banks, as the Seed Vault in Spitzberg, are institutions that save seeds in order to face extinction. But this is no answer to global monocropping.
Challenging the current demand for agricultural products, nowadays more homogenous than ever before, is a condition sine qua non to stimulate the exploitation of forgotten varieties.
Knowledge diversity preserves populations integrity and empowers communities.
For this it must be free to use.
When a knowledge is transmitted orally, there is no legal proof of its existence. It can then be patented by outsiders, therefore depriving the real inventors from their rights, even this of using their invention. This is biopiracy.
The first step to answer this trouble lies in considering social diversity as a part of natural diversity. Protecting one is protecting the other.