With his wife Kathie, also a microbiologist, Tom became deeply involved in conservation ecology. During the 1990s, as residents of Shorewood Hills, Tom and Kathie started volunteer work in what was then called Campus Natural Areas (CNA). Garlic Mustard which they had discovered in the Preserve in 1995, was the motivating factor. They informed the Arboretum of the Garlic Mustard and sent them a check to help get control work started. Subsequently, the Director of the Arboretum Greg Armstrong asked the Brocks to organize volunteer activities at the CNA. For several years, from April 1997-1999, the Brocks led regular Sunday volunteer parties, removing Garlic Mustard and cutting Buckthorn and Honeysuckle. Bob Goodman, Henry Hart, Tom Helgeson, Susan Slapnick, Glenda Denniston, and others joined them. The Brocks also helped the Arboretum, then still in charge of CNA, raise money to support the area and hire Cathie Bruner in 1997 as Field Manager. The Friends of the Campus Natural Areas (since 2005 Lakeshore Nature Preserve) was officially formed on September 19, 2001.
Today, Tom and Kathie Brock are widely acclaimed for the restoration of their Pleasant Valley Conservancy property near Black Earth, which has become a model for land managers and a training ground for the next generation of restoration ecologists. See also TOM's BLOG. Tom and Kathie have published (2019) a two volume online book detailing 25 years of restoration, land management techniques, restoration results, and lessons learned (see Pleasant Valley Conservancy website.).
"While a young professor in microbiology at Indiana, Tom discovered in 1970 the extreme thermophile Thermus aquaticus thriving in a hot spring at Yellowstone National Park. The discovery debunked a key piece of conventional wisdom in biology — that life could not exist past about 158 degrees Fahrenheit. The bacteria’s heat-resistant DNA replicating machinery, Taq polymerase, was turned into a bedrock of modern molecular biology. In 1971, Brock joined the faculty of the Department of Bacteriology at Wisconsin, continuing his ground breaking research on microbes." See more at UW NEWS.