Cascading effects of a highly specialized beech-aphid-fungus interaction on forest regeneration

Smithsonian Environmental Research Center, Edgewater, Maryland, United States
Florida International University, Miami, Florida, United States
DOI
10.7287/peerj.preprints.340v1
Subject Areas
Biodiversity, Ecology, Entomology, Plant Science
Keywords
seedling survival, Grylloprociphilus imbricator, Scorias spongiosa, forest regeneration, Fagus grandifolia
Copyright
© 2014 Cook-Patton et al.
Licence
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
Cite this article
Cook-Patton SS, Maynard L, Lemoine NS, Shue JS, Parker JD. 2014. Cascading effects of a highly specialized beech-aphid-fungus interaction on forest regeneration. PeerJ PrePrints 2:e340v1

Abstract

Specialist herbivores are often thought to benefit the larger plant community, because they prevent their host species from becoming competitively dominant. In contrast, specialist enemies are not generally expected to have negative impacts on non-hosts. However, we describe a cascade of indirect interactions whereby a specialist sooty mold (Scorias spongiosa) colonizes the honeydew from a specialist beech aphid (Grylloprociphilus imbricator), ultimately decreasing the survival of seedlings beneath American beech trees (Fagus grandifolia). A common garden experiment indicated that this mortality resulted from moldy honeydew impairing leaf function rather than from chemical or microbial changes to the soil. In addition, aphids consistently colonized the same beech trees regardless of host density, suggesting that seedling-depauperate islands may form beneath these trees. Thus this highly specialized three-way beech-aphid-fungus interaction has the potential to impact local forest regeneration via a cascade of indirect effects.