Seed predation, not seed dispersal, explains the landscape-level abundance of an early-successional plant
Article first published online: 24 MAR 2006
Journal of Ecology
Volume 94, Issue 4, pages 838–845, July 2006
How to Cite
ORROCK, J. L., LEVEY, D. J., DANIELSON, B. J. and DAMSCHEN, E. I. (2006), Seed predation, not seed dispersal, explains the landscape-level abundance of an early-successional plant. Journal of Ecology, 94: 838–845. doi: 10.1111/j.1365-2745.2006.01125.x
- Issue published online: 24 MAR 2006
- Article first published online: 24 MAR 2006
- Received 28 September 2005 revision accepted 10 January 2006 , Handling Editor: Roy Turkington
- microsite limitation;
- predator limitation;
- seed addition;
- seed dispersal;
- seed limitation
- 1Plants may not occur in a given area if there are no suitable sites for seeds to establish (microsite limitation), if seeds fail to arrive in suitable microsites (dispersal limitation) or if seeds in suitable microsites are destroyed by predators (predator limitation).
- 2We conducted a large-scale study to determine the importance of dispersal limitation and predator limitation in affecting the distribution of pokeweed, Phytolacca americana, in 401-ha experimental patches arrayed in eight groups of five patches distributed across a 300-km2 region.
- 3Microsite limitation was minimized by clearcutting and burning existing vegetation, creating the type of disturbed habitat in which P. americana readily germinates and establishes. The role of dispersal limitation was examined by adding approximately 7000 seeds to each of eight patches in March 2000. The role of seed predation was examined in all 40 patches using experimental exclosures from June 2000 to July 2001.
- 4The number of P. americana plants in September 2000 was unchanged by seed addition. However, fewer P. americana plants were found in patches where seed predators removed more P. americana seeds from experimental exclosures. These data suggest that P. americana is not limited by seed dispersal. Rather, in habitats where microsites are readily available, the abundance of P. americana among patches appears to be limited by the activities of seed predators.
- 5When dispersal and microsites are not limiting, the role of local seed predators can be important for generating emergent, large-scale patterns of plant abundance across landscapes. Moreover, because predators may generate large-scale patterns that resemble other forms of limitation and predators may target specific species, predator impacts should be more frequently incorporated into experiments on the role of seed limitation and plant community composition.