Seed rain and seedling community assembly changes during secondary succession
Open Access
- Author:
- Druschel, Liz
- Area of Honors:
- Biology
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Tomas A Carlo-Joglar, Thesis Supervisor
Timothy J Jegla, Thesis Honors Advisor - Keywords:
- ecology
succession
dispersal
seed rain
seedling recruitment
community assembly
disturbance - Abstract:
- The long-term changes in plant communities after natural and anthropogenic disturbances remain little understood. This is in part because the effects of seed dispersal processes on community composition are left unaccounted for by most studies. Here, we explore how seed dispersal patterns affect community assembly during forest succession by characterizing the possible changes in the seed rain composition and seedling recruitment dynamics. We collected seed rain and seedling recruitment data in wind-disturbed and salvage logged areas at Powdermill Nature Reserve for two years and compared it to prior data collected six years earlier at the same microsites. We analyzed changes in community assembly that took place at the sites during succession between these two sampling periods. We found that the density, richness, and diversity of plant species in the seed rain increased with successional time, while the same parameters decreased for the seedlings. Our results show that following a disturbance, diversity in the seed rain significantly increases as succession proceeds and the community composition shifts. In contrast with core ecology theories that assume that changes in composition are independent of the dispersal processes, this study supports the notion that community-level seed dispersal changes concomitantly with the dynamic changes in succession, which adds more complexity to the process of community assembly.