English to French Science Zoology

Je ne suis pas satisfaite de ma traduction de cette phrase, plus précisément de la liaison entre la première idée (pauvreté du continent africain et problèmes de sa faune) :

Unfortunately Africa is also economically the poorest continent, and habitat is lost as land is cleared, wildlife populations are impacted by exploitation and pollution, and native species struggle to compete with invasive species introduced from other parts of the world.

Le paragraphe précédent est :
For ornithologists, Africa is fascinating. It supports more than 2 500 species of birds, and is home to 24 families that are found nowhere else on Earth. This huge diversity is due in part to the wide range of habitats, from deserts and tropical forests to the rich waters of the Southern Ocean.

Merci pour votre aide.