Ecological Conservatism and Traits Predict Introduction Risk and Co-Occurrence for the Flora of Chicago

Human activity over the past century has dramatically reshaped global plant diversity and distribution. The degradation of natural habitats and redistribution of plant species has changed the makeup of plant communities, generally leading to increased homogenization and decreased biodiversity. While many plant species have suffered from human activity, others have thrived due to their skill at colonizing habitats marked by anthropogenic activity. In this thesis, we examine how various traits impact a plant’s ability to exploit human caused dispersal and disturbance. In chapter 1, we examine the coefficients of conservatism (C-scores) for the flora of the Chicago region. These scores designate a plant’s tolerance to anthropogenic disturbance and we found that they were effective predictors of species assemblages. We also found that traits such as life span, phylogenetic relationship, and wetland affinity were associated with C-score while breeding system and diaspore mass were not. In chapter 2, we examine what traits are associated with non-native introduction and post introduction invasion. We found that tolerance to both a wide range of climates and to anthropogenic disturbance predicted introduction and invasion. Other traits, like lifespan and wetland affinity had different effects during introduction than they did during invasion, while other traits like breeding system never had an effect. The results from these two chapters give insight into what traits help a plant thrive alongside humanity while simultaneously helping aid our understanding of conservation tools like C-score as well as drivers of introduction and invasion.