Present address: Department of Multitrophic Interactions, Netherlands Institute of Ecology, PO Box 40 (Boterhoeksestraat 48), 6666 ZG Heteren, the Netherlands.
Spatial population structure of a specialist leaf-mining moth
Article first published online: 14 APR 2008
© 2008 The Authors. Journal compilation © 2008 British Ecological Society
Journal of Animal Ecology
Volume 77, Issue 4, pages 757–767, July 2008
How to Cite
Gripenberg, S., Ovaskainen, O., Morriën, E. and Roslin, T. (2008), Spatial population structure of a specialist leaf-mining moth. Journal of Animal Ecology, 77: 757–767. doi: 10.1111/j.1365-2656.2008.01396.x
- Issue published online: 14 APR 2008
- Article first published online: 14 APR 2008
- Received 7 June 2007; accepted 3 February 2008Handling Editor: Ottar Bjornstad
- leaf miner;
- local and regional dynamics;
- sources and sinks;
- spatially structured population model;
- trees as islands
- 1The spatial structure of natural populations may profoundly influence their dynamics. Depending on the frequency of movements among local populations and the consequent balance between local and regional population processes, earlier work has attempted to classify metapopulations into clear-cut categories, ranging from patchy populations to sets of remnant populations. In an alternative, dichotomous scheme, local populations have been classified as self-sustaining populations generating a surplus of individuals (sources) and those depending on immigration for persistence (sinks).
- 2In this paper, we describe the spatial population structure of the leaf-mining moth Tischeria ekebladella, a specialist herbivore of the pedunculate oak Quercus robur. We relate moth dispersal to the distribution of oaks on Wattkast, a small island (5 km2) off the south-western coast of Finland.
- 3We build a spatially realistic metapopulation model derived from assumptions concerning the behaviour of individual moths, and show that the model is able to explain part of the variation in observed patterns of occurrence and colonization.
- 4While the species was always present on large trees, a considerable proportion of the local populations associated with small oaks showed extinction–recolonization dynamics. The vast majority of moth individuals occur on large trees.
- 5According to model predictions, the dominance of local vs. regional processes in tree-specific moth dynamics varies drastically across the landscape. Most local populations may be defined broadly as ‘sinks’, as model simulations suggest that in the absence of immigration, only the largest oaks will sustain viable moth populations. Large trees in areas of high oak density will contribute most to the overall persistence of the metapopulation by acting as sources of moths colonizing other trees.
- 6No single ‘metapopulation type’ will suffice to describe the oak–moth system. Instead, our study supports the notion that real populations are often a mix of earlier identified categories. The level to which local populations may persist after landscape modification will vary across the landscape, and sweeping classifications of metapopulations into single categories will contribute little to understanding how individual local populations contribute to the overall persistence of the system.