books.google.com.au - It is generally recognized that where earthworms are abundant they can exert significant influence on the structure and function of soils. Compared to other biogeographic regions of Earth, however, surprisingly little is known about the earthworm fauna of the western hemisphere and their role in soil...http://books.google.com.au/books/about/Earthworm_ecology_and_biogeography_in_No.html?id=BoO_oF3oCPEC&utm_source=gb-gplus-shareEarthworm ecology and biogeography in North America
