Biodiversity, the foundation for ecosystem functions and services, is threatened by human activities. In order to protect sensitive biodiversity, a certain goal in ecology is to understand the mechanisms that determine species competition and extinction.
In this thesis, I used several methods to investigate and predict the effect of human activities on grassland plant diversity. My first approach combined height and cover of each species in community, thereby allowing me to examine the importance of changes in space resource utilization (SRU) of community for changes in plant diversity in response to human activities.
Based on this approach, I checked the changes in SRU of different abundance groups and the relationships with changes in plant diversity. This allowed me to optimize the predictor to quantify diversity dynamics more accurately. Then, another approach linked instantaneous growth rates during growing season to species status and fate when competing with other species. This approach allowed me to examine the role of growth rate on short-term competitive dominance and the critical time during growing season when it is most important.
These approaches take into account the different changes of species in the community and the pivotal traits in the competition process in response to human disturbances, which are most important foundation of management interventions on plant communities, thereby facilitating efforts to maintain and recover plant diversity.