住処 is a more general term for a dwelling or den, often used for animals or metaphorically for people, while 生息地 is specifically an ecological habitat.
Etymology
Compound of 生息 (せいそく, 'inhabiting, living') + 地 (ち, 'land, place'). The kanji 生息 combines 生 ('life') and 息 ('breath'), together meaning 'to live, to inhabit'.
