Home About Browse Search

Estimating coextinction risks from epidemic tree death

affiliate lichen communities among diseased host tree populations of fraxinus excelsior.

Thor, Göran and Jönsson, Mari (2012). Estimating coextinction risks from epidemic tree death. PloS one. 7 :9 , 1-10
[Research article]

[img] PDF

Official URL: http://dx.doi.org/10.1371/journal.pone.0045701


At least 10% of the world's tree species are threatened with extinction and pathogens are increasingly implicated in tree threats. Coextinction and threats to affiliates as a consequence of the loss or decline of their host trees is a poorly understood phenomenon. Ash dieback is an emerging infectious disease causing severe dieback of common ash Fraxinus excelsior throughout Europe. We utilized available empirical data on affiliate epiphytic lichen diversity (174 species and 17,800 observations) among 20 ash dieback infected host tree populations of F. excelsior on the island Gotland in the Baltic Sea, Sweden. From this, we used structured scenario projections scaled with empirical data of ash dieback disease to generate probabilistic models for estimating local and regional lichen coextinction risks. Average coextinction probabilities (A - ) were 0.38 (95% CI 60.09) for lichens occurring on F. excelsior and 0.14 (95% CI 60.03) when considering lichen persistence on all tree species. A - was strongly linked to local disease incidence levels and generally increasing with lichen host specificity to F. excelsior and decreasing population size. Coextinctions reduced affiliate community viability, with significant local reductions in species richness and shifts in lichen species composition. Affiliates were projected to become locally extirpated before their hosts, illuminating the need to also consider host tree declines. Traditionally managed open wooded meadows had the highest incidence of ash dieback disease and significantly higher proportions of affiliate species projected to go extinct, compared with unmanaged closed forests and semi-open grazed sites. Most cothreatened species were not previously red-listed, which suggest that tree epidemics cause many unforeseen threats to species. Our analysis shows that epidemic tree deaths represent an insidious, mostly overlooked, threat to sessile affiliate communities in forested environments. Current conservation and management strategies must account for secondary extinctions associated with epidemic tree death.

Authors/Creators:Thor, Göran and Jönsson, Mari
Title:Estimating coextinction risks from epidemic tree death
Subtitle:affiliate lichen communities among diseased host tree populations of fraxinus excelsior.
Series Name/Journal:PloS one
Year of publishing :2012
Page range:1-10
Number of Pages:10
Publisher:Public Library of Science
Publication Type:Research article
Article category:Scientific peer reviewed
Version:Published version
Full Text Status:Public
Agris subject categories.:K Forestry > K70 Forest injuries and protection
Subjects:(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Forest Science
Keywords:epidemic tree death, pathogens, extincion, coextinction, conservation strategies
Permanent URL:
Additional ID:
Type of IDID
ID Code:10327
Department:(NL, NJ) > Dept. of Ecology
(S) > Dept. of Ecology
Deposited By: SLUpub Connector
Deposited On:14 Jun 2013 11:26
Metadata Last Modified:15 Dec 2015 09:41

Repository Staff Only: item control page


Downloads per year (since September 2012)

View more statistics