Invasion and the regulation of plant populations by pathogens

Abstract

The potential of pathogens to have dramatic impacts on plant populations is made clear by familiar stories of the Irish potato famine (Fry and Goodwin 199 7), the ecological extinction of chestnuts caused by chestnut blight (Anagnostakis 1987), and the transformation of Australian Jarrah forests to scrubland by Phytophthora cinnamomi (Weste and Marks 1987). Similarly, the annual worldwide expenditure of over $6.6 billion in fungicide application (Donaldson et al. 2002) reflects the toll fungal pathogens alone can take on plant growth and fecundity in agricultural systems. Some of the most notable examples of these impacts arise when pathogens are introduced into novel biological environments; invasive and emergent pathogens continue to frustrate the best efforts of resource managers, conservation biologists, and plant protection agencies (Weste and Marks 1987, Daughtrey et al. 1996, Goodell et al. 2000, Gordon et al. 2001, McDonald and Hoff 2001, Wingfield et al. 2001, Gilbert 2002, Rizzo and Garbelotto 2003, Parker and Gilbert 2004). Concurrent with efforts to reduce the impacts of unwanted diseases, there is broad interest among researchers, agriculturalists, and land managers to harness the destructive potential of plant pathogens to control weedy plants (Hasan and Ayres 1990, Charudattan and Dinoor 2000). © 2006 Springer. All Rights Reserved.