TreeSearch"Treesearch is an online system for sharing free, full text publications by Research and Development scientists in the US Forest Service...including papers appearing in journals, conference proceedings, or books. All publications...are based on peer reviewed research to make sure they provide the best scientific information possible....Searches in Treesearch are focused on the metadata surrounding a publication, things like author, title, and so forth." Over 40,000 publications to date. [From http://www.treesearch.fs.fed.us/about/]