Here is the (long) report on the UK academic staff reading patterns.
A report my team did for the Publishing Research Consortium on factors that influence reading is the second report listed at this link. They have also sponsored research on peer review and other things. It is a group of publishers, but they put no constraints on the research.
Sounds like in March they covered many of the same issues. See report at:
OSTI (Office of Scientific and Technical Information) maintains the Eprint Network, which lists available preprint archives by subject. One subject is environmental sciences and ecology and they list many.