Pulsed Resources and Consumer Communities in Terrestrial Systems

In deciduous and coniferous forests dominated by mast-producing trees, such as oaks, consumers are confronted with the sporadic production of abundant resources. Mast-consuming animals, such as the white-footed mouse (Peromyscus leucopus) and eastern chipmunk (Tamias striatus), rely on these pulsed resources.

Intermittent acorn production directly effects white-footed mouse population size. As a "hub species," white-footed mouse populations initiate cascades of direct and indirect effects that permeate throughout these forest-based food webs. Their population size is tied to Lyme disease prevalence, gypsy moth predation, songbird populations and seed survivorship and seedling establishment.

Mast-Consuming Animals

"Mast production" or "masting" refers to the synchronous, episodic production of heavy seed crops by a population of plants. We have used both long-term monitoring and experimental enhancement of acorn abundance to determine the effects of acorns on mouse populations.

Pulsed Resources

Pulsed resource theory now integrates concurrent theories of top-down and bottom-up control, direct and indirect effects on population dynamics, and temporal variation in interaction webs.

Hub Species

Populations of mast-consuming mammals, such as the white-footed mouse (Peromyscus leucopus), and eastern chipmunk (Tamias striatus) initiate cascades of direct and indirect effects that permeate throughout forest-based food webs.

gypsy moth

Gypsy Moth Predation & Mice

During outbreak years, gypsy moths, an exotic pest of oak forests in eastern North America, can defoliate thousands of hectares of forest and kill millions of trees. White-footed mice are by far the most effective predators on the pupal (cocoon) stage in the life cycle of the gypsy moth.

veery

Songbird Populations & Mice

White-footed mice and eastern chipmunks attack eggs within nests of ground-nesting and shrub-nesting birds. Our long-term monitoring data indicate that fledging success of veeries, red-eyed vireos, and woodthrushes is poor in years of high mouse abundance and good in years of low mouse abundance.

Seed Survivorship & Seedling Establishment

Not only do tree seeds have an important bottom-up effect on mice, but also mice have strong top-down effects on seed survival and seedling establishment. Previous studies conducted in old fields adjacent to deciduous forest showed that the survival of experimentally introduced seeds was strongly negatively correlated with mouse abundance.

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