Abstract:

Seed dispersal links the reproductive cycle of adult plants with the establishment of their offspring and is widely recognized as a process that has a profound effect on the structure of tree communities. Although ecologists as early as Darwin realized the importance of seed dispersal, the scientific study of seed rain did not gain momentum until the early 1980s. A considerable amount of seed rain research has been conducted since then. Here we focused on seed rain studies of woody plants in forests. Seed rain monitoring methods are introduced, including seedtrap set, seed collection, separation, and identification. We also review recent progress in these studies—temporal and spatial variation in seed rain (seasonal, intra-annual, and spatial variations), recruitment limitation and its role in species coexistence, testing the negative density-dependent hypothesis, and comparisons between seed rain and later life history phases (soil seed bank, seedling, sapling and adult). We recommend that future studies should pay attention to conducting long-term seed rain monitoring, examining cross-site recruitment limitation, exploring whether negative density-dependence at the earliest stages of regeneration is greater in the tropics than at higher latitudes, and developing exciting new techniques including the analysis of stable isotope ratios and molecular genetic markers.

Key words: negative density dependence, recruitment limitation, seed dispersal, seed production, species coexistence