We analyzed live-trapping data from 10 years (1983-1992) of a long-term study of forest ecosystems in southern Maine to investigate relationships between seed fall of red oak (Quercus rubra), white pine (Pinus strobus), and red maple (Acer rubrum), and populations of Peromyscus leucopus and Clethrionomys gapperi. Spring populations of Peromyscus were correlated positively with crops of both red oak and white pine in the previous autumn; summer populations were correlated only with the acorn crop of red oak in the previous year. Populations of Clethrionomys were not correlated with either red oak or white pine in spring or summer. The increase from spring to summer in Peromyscus was associated positively with the magnitude of seed fall from red maple in the current year. Following years of above average acorn production of red oak, adult male and female Peromyscus weighed more than in years following low acorn production. Following 2 years of high acorn production, captures of Peromyscus were associated positively with the number of live red oaks >10 cm diameter at breast height per 0.25-ha quadrat. Group-selection logging also was associated with increased summer captures of Peromyscus per quadrat for 2 of 4 years, probably due to an increase in both herbaceous cover and fruit production of shrubs.