| The ubiquity of fleshy-fruited plants in the tropics suggests that animal-mediated seed dispersal is important for plant recruitment. By creating the initial spatial template of seeds, frugivores are thought to influence recruitment and spatial dispersion patterns in all subsequent plant life history stages. However, plant establishment depends on a series of steps influenced not only by seed dispersal but also by post-dispersal processes, such as seed survival, seedling establishment, and recruitment into juvenile and adult stages. Thus, it is possible that initial patterns established by frugivores are largely erased by subsequent processes. Few studies have studied successive life-history stages of animal-dispersed plants to determine if initial patterns established by frugivores persist to later stages. I addressed this issue by quantifying patterns of dispersal and recruitment in a tropical forest in Kibale National Park, Uganda. First, to better understand the link between frugivore behavior and subsequent seedling recruitment, I examined seed dispersal and seedling establishment of Monodora myristica, a tree species whose fruit morphology suggests it is dispersed by only the largest arboreal frugivores. I found that large-bodied primates played a critical role in initial stages of M. myristica seed dispersal by opening the hard-husked fruits and dispersing the large seeds away from parent plants. However, spatial and temporal variation in post-dispersal processes, such as seed predation, subsequently influenced recruitment patterns. At some spatial and temporal scales, this variation in post-dispersal processes reduces the predictability of frugivore actions on seedling recruitment. Second, to assess whether patterns of plant dispersion established by frugivores persist to older stages, I examined whether changes in pattern of dispersion from seedlings to trees differed between stands for six animal-dispersed species. I found that, for some species, spatial patterns across size classes were similar between stands, indicating that processes likely operate similarly between stands. However, in other species, patterns differed between stands, indicating that initial spatial patterns may be disrupted in later stages. Thus, similar to the first study's findings, spatial and temporal variation in processes operating at later stages may result in little concordance between frugivore seed deposition and plant recruitment and spatial dispersion patterns. |
