| Popis: |
Annual plants are important colonizers of the bare sandy areas that typify the pioneer zone of many coastal beaches. The spatial distribution of the potential seed rain in autumn, transient seed bank in early spring, and seedling recruitment in late spring were examined for the summer annuals in a 40 × 45 m section of beach on Staten Island, NY. The relationship of the dominant perennial, Ammophila breviligulata, to recruitment was also explored. Estimated seed rain was very high, showing species-specific distribution patterns along the shore-to-land gradient for Triplasis purpurea, Cenchrus tribuloides, and Heterotheca subaxillaris, the most abundant native annuals. Seed rain and spring recruitment for T. purpurea and C. tribuloides were greatest in regions of the beach where A. breviligulata was less abundant. Recruitment of T. purpurea and C. tribuloides, but not H. subaxillaris, was negatively associated with living A. breviligulata. Summed over all annuals, recruitment was 73.6 ± 5.2 seedlin... |
