There have been relatively few tests of resource-ratio theory in terrestrial systems. Additionally, resources are known to be an important factor determining the success of invasive species. Here I discuss how the study by Newingham and Belnap (pp. 29?40, this issue) tests predictions of resource-ratio theory and how they apply it to questions of invasion by Bromus tectorum in a terrestrial grassland. Published in Plant and Soil, volume 280, issue 1-2, on pages 23 - 27, in 2006.
