Plant communities worldwide show varied responses to nutrient enrichment--including shifts in species identity, decreased diversity, and changes in functional trait composition--but the factors determining community recovery after the cessation of nutrient addition are still relatively understudied. Here, we investigate the drivers and patterns of recovery following experimental nutrient addition in a tundra community. We present data from a manipulative experiment of six years of nutrient addition followed by eight years of recovery, in which we examined the role of "resource-acquisitive" plant traits in the persistence of nutrient addition effects. Specifically, we tested whether height, specific leaf area, and foliar C:N predicted species' persistent responses to nutrient enrichment. Additionally, we asked whether trait-based shifts were associated with litter accumulation, differences in soil nutrients, and persistent differences in plant community composition.
Results/Conclusions
We found that plants with fast-growing traits, including higher specific leaf area and height and lower foliar C:N, were more likely to show persistent increase in fertilized plots than control plots. Additionally, although graminoids responded most strongly to the initial fertilization treatment, forb species were the most vulnerable to persistent effects, especially in more fertile sites. Finally, we present potential mechanisms for the persistence of fertilization effects in tundra communities, including trait-based plant responses to resource enhancements, litter build-up and shifts in soil nutrients. Our results demonstrate the potential for lasting effects of nutrient enrichment in tundra and identify species traits related to rapid growth and nutrient-use efficiency as the main predictors of the persistence of nutrient enrichment effects. These findings highlightthe usefulness of trait-based approach for understanding the potential for recovery from nutrient enrichment.