Abstract:
AIM : Spreading infectious diseases associated with introduced pathogens can have
devastating effects on native biota and human livelihoods. We analyse the global
distribution of 100 major alien fungal and oomycete pathogens with substantial
socio-economic and environmental impacts and examine their taxonomy, ecological
characteristics, temporal accumulation trajectories, regional hot- and coldspots of
taxon richness and taxon flows between continents.
LOCATION : Global.
TAXON : Alien/cryptogenic fungi and fungus-like oomycetes, pathogenic to plants or
animals.
METHODS : To identify over/underrepresented classes and phyla, we performed Chi2
tests of independence. To describe spatial patterns, we calculated the region-wise
richness and identified hot- and coldspots, defined as residuals after correcting taxon
richness for region area and sampling effort via a quasi-Poisson regression. We examined
the relationship with environmental and socio-economic drivers with a multiple
linear regression and evaluated a potential island effect. Regional first records were
pooled over 20-year periods, and for global flows the links between the native range
to the alien regions were mapped.
RESULTS : Peronosporomycetes (Oomycota) were overrepresented among taxa and regional
taxon richness was positively correlated with area and sampling effort. While
no island effect was found, likely due to host limitations, hotspots were correlated
with human modification of terrestrial land, per capita gross domestic product, temperate
and tropical forest biomes, and orobiomes. Regional first records have increased
steeply in recent decades. While Europe and Northern America were major
recipients, about half of the taxa originate from Asia.
MAIN CONCLUSIONS : We highlight the putative importance of anthropogenic drivers,
such as land use providing a conducive environment, contact opportunities and susceptible
hosts, as well as economic wealth likely increasing colonisation pressure.
While most taxa were associated with socio-economic impacts, possibly partly due to
a bias in research focus, about a third show substantial impacts to both socio-economy
and the environment, underscoring the importance of maintaining a wholescale
perspective across natural and managed systems.
