Scopus indexes content from a myriad of journal and publishers (including content relevant to ecology), their inclusion in the database is vetted and selected by an independent review board. Due to Scopus' underlying metadata architecture, there are many ways to navigate between and within articles, authors and citations.
Over 50,000 "free, full text publications by Research and Development scientists in the USDA Forest Service. Included in Treesearch are scholarly works authored by the agency’s scientists and published by journals, in conference proceedings, or in books. Treesearch also offers scholarly works published by the agency which may or may not have been authored by agency researchers. All publications appearing in Treesearch are based on peer reviewed research to make sure they provide the best scientific information possible."
Covers the international literature on the biomedical sciences, including the the biological and physical sciences, humanities, and information science as they relate to medicine. Can be searched interactively with other NCBI databases, including PubMedCentral and PubBooks.