How about gifting your friend a book related to biodiversity conservation? Some popular choices include The Sixth Extinction by Elizabeth Kolbert or Half-Earth: Our Planet's Fight for Life by E.O. Wilson. Additionally, you could consider donating to a conservation organization in your friend's name, such as The Nature Conservancy or the World Wildlife Fund. You could also look into gifting your friend a sustainable living plant or a nature-inspired art piece created by a local artist.
Or you can get her/him a star map with an important date you share.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.