Cynthia Chang, former EEB graduate student, examined the role of diversity at both the community and population level on invasion resistance and productivity in the tallgrass prairie. At the population level, she looked at the relationship between genotype and phenotype variation in Big Bluestem, a dominant species in the tallgrass prairie; At the community level, she looked at the relationship between species composition and trait variation. Looking at all levels of diversity, she hoped to reveal basic patterns and mechanisms behind two important ecosystem processes in the tallgrass prairie, invasion resistance and productivity.