Sentence:  Similarly, at Fresh Kills, a closed landfill with barely any living soil or biodiversity, the task of the layers is to build a new thick surface over time—an ecologically engineered surface that will <WSD>self-colonize</WSD> and grow and adapt. 
Meaning of the word marked with <WSD> tags:  To be introduced into an ecosystem through natural processes, as opposed to deliberate introduction by people.