Results/Conclusions Using grassland data from Cedar Creek Minnesota, we ran two different models to assess the importance of rare species on community trait space based on two different extinction scenarios. First, we ran a model where species were lost randomly. This analysis found that rare species and common species were both equally likely to contribute to community trait space; furthermore, this similarity remained when using different definitions of rarity to rank the species. Second, we ran a model where species were lost non-randomly, from most rare to most common. Using this simulation, we find that rare species appear to contribute more to community trait space than do common species when ranked by geographic range and habitat specificity. This suggests that the random loss of rare species does not have a large impact on ecosystem function, given that rare and common species contribute equally to trait space. However, when considering non-random species loss, where rare species are lost first, it appears as if the cumulative loss of rare species does play an important role in ecosystem function.