One direction I’ve gone with corpus linguistics is towards the study of environmental discourse, and I’ve begun building and analyzing a corpus of environmental texts. I’m compiling a corpus of texts all referencing the same environmental issue over its 8-9 year lifespan in southern Arizona and integrating ecolinguistic/ecological frameworks with corpus analysis methods.
So, if the term ecolinguistics piqued your interest, you should check out The Language and Ecology Research Forum curated by Arran Stibbe at the University of Gloucester. The page has a great bibliography. Yes, some of it may not be of direct interest to corpus linguists, but there are certainly some interesting selections.