title: Predation and food web structure along a habitat duration gradient.
abstract: Food web statistics showed a complex relationship with measures of habitat variability in temporary ponds. Connectance was highest in short-duration, highly variable habitats, and lowest in habitats of intermediate duration and variability. The number of links and links/taxon increased with increasing duration. Much of the variation in the food web statistics could be explained by a strong linear relationship between number of taxa and number of links/taxon and a quadratic relationship of taxa number with the number of links. However, after accounting for this variation, there remained a relationship of duration with links and links/taxon. The relationship between the food web statistics and duration corresponded to experimental evaluations of predation in these habitats that showed an increasing importance of predation in long-duration habitats. The food web statistics, however, missed threshold effects in the relationship between predation and habitat duration. Differences in food web statistics before and after a regional drought could be explained by a decrease in taxa number after the drought. Connectance was the most robust statistic in relation to taxa number, but was also the least sensitive to changes in habitat characteristics.
authors.affiliation: Department of Urban and Regional Planning and Illinois Natural History Survey, University of Illinois at Urbana-Champaign, 611 E. Lorado Taft Drive, Champaign, IL 61820, USA, , , , , , US.
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Schneider
keywords: Key words Food webs ;   Temporary ponds ;  Connectance;  Habitat variability ;  Predation 