Spatial and temporal patterns of postdispersal seed predation

Abstract

We experimentally examined spatial and temporal patterns of postdispersal seed predation of vertebrate-dispersed plant species in temperate woodland and old-field habitats. Rodents were the principal predators. Rates of seed loss varied with microhabitat (near logs, tree trunks, and open forest floor), macrohabitat (old field, forest), plant species, year, and time of dispersal within a year. Levels of final mortality (= mortality at final census) did not vary with microhabitat or time of dispersal but did vary between macrohabitats, plant species, and years. The variability of our results (i) indicates the importance of dispersing many seeds into many different types of micro- and macro-habitats, (ii) supports the view of a diffuse mutualism between plants and their vertebrate dispersers, and (iii) suggests that to detect important trends in patterns of postdispersal seed predation, and ultimately plant recruitment, longer term studies are imperative. Key words: community structure, seed predation, rodents, plant populations, plant recruitment, vertebrate seed dispersal.