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Spatial and temporal genetic structure at the fourth trophic level in a fragmented landscape
Abhilash Nair1, Toby Fountain2, Suvi Ikonen2
1Metapopulation Research Centre, Department of Biosciences, University of Helsinki, PO Box 65, 00014 Helsinki, Finland abhilash.nair@helsinki.fi.
Proceedings. Biological Sciences
|May 27, 2016
Summary
Species in fragmented habitats must disperse to survive. Higher trophic level species, like hyperparasitoids, show less genetic structure than their hosts, confirming adaptation but with limits.
Area of Science:
- Ecology
- Population Genetics
- Conservation Biology
Background:
- Habitat fragmentation impacts species, especially those at higher trophic levels.
- Specialized species require high dispersal to utilize scarce resources in fragmented landscapes.
- Parasitoid populations are expected to exhibit lower genetic structure than their hosts.
Purpose of the Study:
- To investigate the temporal and spatial genetic structure of a hyperparasitoid in a fragmented landscape.
- To compare the genetic structure of a hyperparasitoid with its host parasitoid and butterfly host.
- To test the hypothesis that population genetic structure decreases with increasing trophic level.
Main Methods:
- Microsatellite markers were used to analyze genetic structure.
- A 50 × 70 km fragmented landscape was studied.
- Genetic data were compared across four trophic levels: hyperparasitoid, host parasitoid, butterfly host, and potentially a lower trophic level.
Main Results:
- Population genetic structure decreased significantly with increasing trophic level.
- The hyperparasitoid showed fewer genetic clusters (K=4) than its host parasitoid (K=15) and the host butterfly (K=27).
- Hyperparasitoid genetic structure exhibited temporal variation, with increased differentiation linked to population size reduction.
Conclusions:
- Specialized species demonstrate dispersive adaptations to fragmented host resources.
- These adaptations have inherent limitations, as observed in the hyperparasitoid's genetic structure.
- Understanding genetic structure across trophic levels is crucial for conservation in fragmented ecosystems.
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