Treefalls and Colonization Patterns of Temperate Forest Herbs

The relative ability of various guilds of herbs to colonize fallen logs and pits at the bases of uprooted trees was studied in three Illinois forests. Fallen logs in various stages of decay covered approximately 1.9% of the forest floor in all three study areas; study plots averaged 14.5 logs ^ 20 cm at midpoint per 0.25 ha. Herbaceous species differed in their probabilities of colonizing fallen logs and pits; however, most species colonized some sites. Individual logs and pits were colonized generally by several species. Most colonization appeared to be local, from plants within 1 m of the log or pit; but colonizations from greater distances occurred in both the spring and summer flora. Spring-ephemeral species as a group appeared to be better colonizers; however, summer species were better at longer distance colonizations. Seeds of no* single specific dispersal type predominated in colonizations from distances > 1 m. In general, however, plants with animal-dispersed seeds predominated in colonization of pits, although no such pattern occurred in colonization of logs. The colonization strategies of herbs in these communities may be geared to an important degree to the colonization of these and related disturbance areas.