Forest species diversity reduces disease risk in a generalist plant pathogen invasion

Ecology Letters
By: , and 

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Abstract

Empirical evidence suggests that biodiversity loss can increase disease transmission, yet our understanding of the 'diversity-disease hypothesis' for generalist pathogens in natural ecosystems is limited. We used a landscape epidemiological approach to examine two scenarios regarding diversity effects on the emerging plant pathogen Phytophthora ramorum across a broad, heterogeneous ecoregion: (1) an amplification effect exists where disease risk is greater in areas with higher plant diversity due to the pathogen's wide host range, or (2) a dilution effect where risk is reduced with increasing diversity due to lower competency of alternative hosts. We found evidence for pathogen dilution, whereby disease risk was lower in sites with higher species diversity, after accounting for potentially confounding effects of host density and landscape heterogeneity. Our results suggest that although nearly all plants in the ecosystem are hosts, alternative hosts may dilute disease transmission by competent hosts, thereby buffering forest health from infectious disease.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Forest species diversity reduces disease risk in a generalist plant pathogen invasion
Series title Ecology Letters
DOI 10.1111/j.1461-0248.2011.01679.x
Volume 14
Issue 11
Year Published 2011
Language English
Publisher Blackwell Publishing
Description 9 p.
First page 1108
Last page 1116
Online Only (Y/N) N
Additional Online Files (Y/N) N