Ecologists have been fascinated by the relationship between plant species diversity and ecosystem productivity for many years. It is becoming increasingly important to understand this relationship as anthropogenic environmental changes such as nitrogen deposition fundamentally alter natural systems. At local scales, experimental research shows that species diversity tends to decline as resource availability increases. To date, diversity responses to nutrient enrichment have been quantified almost entirely by changes in taxonomic richness. Thus, we know little about the characteristics ¿ or functional traits ¿ of those species which decline. This research will seek to determine whether plant functional traits can predict shifts in species composition, species richness, and productivity in response to nutrient enrichment. This focus on functional traits will facilitate comparison across ecosystem types, and generalization regarding species losses and their consequences in response to environmental change. collapse