 One of his most cited articles is the 1994 "Nature" article on the "Biodiversity and stability in grasslands" which provided data regarding an experiment that began in 1982 with more than 200 plots in a grassland field in the Cedar Creek Ecosystem Science Reserve in Minnesota.Each of these plots was continuously monitored for 20 years for factors such as species richness and biomass created by the community.Tilman's article looked at data both prior to and following a drought on the grassland plots in 1988, which provided surprising results.