Centre for Plant Biodiversity Research
Temporal and spatial changes in a metapopulation of the rust pathogen Triphragmium ulmariae and its host, Filipendula ulmaria
(1) Centre for Plant Biodiversity Research, G.P.O. Box 1600, Canberra, A.C.T. 2601 Australia.
(2) Department of Ecological Botany, Umea University, S-90187 Umea, Sweden.
(3) INRE Biometrics Unit, CSIRO, GPO Box 1666, Canberra, A.C.T. 2601 Australia.
Summary1. The numerical dynamics of a rust disease caused by the pathogen Triphragmium ulmariae was studied in a metapopulation of 129 discrete populations of the host plant Filipendula ulmaria.
2. Over the four years 1990-1993, 37% of the populations were consistently infected by the pathogen while 43% were always healthy. In the remaining 20% of populations, the presence of disease fluctuated from year-to-year.
3. In each of the four years the incidence of disease was strongly positively correlated with the logarithm of host population size (P<0.001). Disease incidence was also weakly affected by the type of shore on which host populations grew but not by their degree of exposure.
4. The severity of disease occurring in infected populations was weakly positively correlated with the logarithm of population size (P<0.05). However, the relationship between the density of individuals within populations and disease prevalence showed no density-dependence.
5. The distribution of disease among populations of the metapopulation had a significant spatial component in two of the years, with infected populations being closer together than would be expected by chance.
Keywordsdisease, epidemiology, host-pathogen interactions, thresholds
Published in: Journal of Ecology Vol. 83: 979-989 (1995).
Updated 15 November, 1999 by Andrew Lyne