Showing papers by "David L. Strayer published in 1986"

An Energy Budget for the Zoobenthos of Mirror Lake, New Hampshire

Abstract: We combined our data on abundance, biomass, and diet of benthic animals in Mirror Lake with estimates of annual P/B (production/biomass) ratios to construct a model of energy flow through the zoobenthos of this small, oligotrophic lake. Because we included the rarely studied mei- ofauna (all metazoans < 0.5 mm), our model provides the first accounting of energy flow through an entire zoobenthic community in freshwater. In Mirror Lake, about half of the zoobenthic assimilation of carbon (14 g m-2-yr-') is due to the meiofauna. Although detritivory supports about half of community assimilation, benthic algae are an important energy source to the zoobenthos, especially in the littoral zone. We suggest that the importance of benthic algae in lacustrine energy budgets has been underestimated. Major fates of zoobenthic production in Mirror Lake include invertebrate pre- dation, insect emergence, and fish predation. Invertebrate predation is the dominant fate and accounts for 80% of zoobenthic production.

The size structure of a lacustrine zoobenthic community.

Abstract: Data from Mirror Lake, New Hampshire, are used to construct the first quantitative description of the size structure of a freshwater benthic animal community. Size spectra of the benthic animal community, whether expressed as animal density, biomass, species richness, or assimilation, are generally unimodal. These spectra are strikingly different from the characteristically bimodal size spectra reported for marine benthic communities. There is no indication in these size spectra that the meiofauna and macrofauna are distinct ecological entities in Mirror Lake, as has been suggested for marine benthic communities.

The effects of forest disturbance on land gastropod communities in northern New England

Abstract: We studied the gastropod communities of 16 forested sites in northern New England that had been disturbed by clear-cutting, agricultural cropping, or forest fires. There was no clear relationship between the density, species richness, or composition of the gastropod community and the time elapsed since disturbance. This result contrasts with previous studies, which reported strong correlations between the age of forested stands and the structure of gastropod communities. We suggest that gastropod communities in our study sites recovered rapidly following disturbance because of the small area of the disturbed sites, which facilitated recolonization from surrounding areas, and because of the rapid recovery of the function of the vegetation following forest disturbance in northern New England.