Document Type

Article

Publication Date

8-1-2015

Publication Title

Ecology

DOI

10.1890/14-1526.1

ISSN

1939-9170

Abstract

Species losses are predicted to simplify food web structure, and disease‐driven amphibian declines in Central America offer an opportunity to test this prediction. Assessment of insect community composition, combined with gut content analyses, was used to generate periphyton–insect food webs for a Panamanian stream, both pre‐ and post‐amphibian decline. We then used network analysis to assess the effects of amphibian declines on food web structure. Although 48% of consumer taxa, including many insect taxa, were lost between pre‐ and post‐amphibian decline sampling dates, connectance declined by less than 3%. We then quantified the resilience of food web structure by calculating the number of expected cascading extirpations from the loss of tadpoles. This analysis showed the expected effects of species loss on connectance and linkage density to be more than 60% and 40%, respectively, than were actually observed. Instead, new trophic linkages in the post‐decline food web reorganized the food web topology, changing the identity of “hub” taxa, and consequently reducing the effects of amphibian declines on many food web attributes. Resilience of food web attributes was driven by a combination of changes in consumer diets, particularly those of insect predators, as well as the appearance of generalist insect consumers, suggesting that food web structure is maintained by factors independent of the original trophic linkages.

Comments

© 2015 by the Ecological Society of America. The Author(s) shall retain the right to quote from, reprint, translate and reproduce the work, in part or in full, in any book or article he/she may later write, or in any public presentation. The Author may post the work in a publicly accessible form on his/her personal or home institution's webpages. If the Author(s) reproduces a portion of the work in a book, article or other media, the legend or caption of any table or figure that represents data from the work, in original or modified form, shall cite the work as the source of those data. In addition, the Author(s) shall have the right to photocopy the work for his/her own use or public distribution. If the Author(s) reprints, translates or photocopies the work, the original copyright notice, as it appears in the journal, must be included. The Author retains all proprietary rights other than copyright, such as patent rights.

This article was retrieved from Ecology.

Share

COinS