Global change, parasites, and community assembly: How a parasite expanded its range in the shadow of its host
4 likes
views
This presentation was given at the Oosting Memorial Symposium on April 17, 2009. The authors were Yi-Hsin Erica Tsai and Paul S. Manos. Abstract: Because species respond individually to climate change, understanding community assembly requires examination of multiple species from a diversity of forest niches. We present the phylogeographic history of an understory, parasitic herb (Epifagus virginiana, beechdrop) that has an obligate and host specific relationship with a common eastern North American forest tree (Fagus grandifolia, American beech). The migration histories of the host and parasite were compared to elucidate potential limits on the parasite’s range and to understand their responses to shared climate change. Two chloroplast DNA regions were sequenced and landscape genetic and coalescent methods were used to reconstruct the post-glacial migration history of the parasite. Epifagus virginiana is shown to have migrated from the southern Appalachians into the Northeast and then westward into the Midwest. The parasite's pattern of expansion parallels the development of beech forests but differs from the routes of initial range expansion of beech. This suggests that host density effects drive the distributional changes in the parasite, which are further confirmed in fine scale studies. The composite migration history of this parasite and its host shows how two diverse components of a forest community colonized the landscape separately -- even as aspects of the host's distribution greatly influenced the path of the parasite -- before reassembling into their present day co-distributed range. The animations from the powerpoint were partly converted using code from Neil Mitchell's Haskell Blog, http://neilmitchell.blogspot.com/2007/11/creating-pdf-from-powerpoint-with.html.
Recommended
Global change, parasites, and community assembly: How a parasite expanded its range in the shadow of its host
- Global change, parasites, and community assembly: How a parasite expanded its range in the shadow of its host Yi-Hsin Erica Tsai Paul S. Manos Department of Biology Duke University
- Climate change and a species’ response
- Climate change and a species’ response Climate change
- Climate change and a species’ response Climate change
- Climate change and a species’ response Climate change
- Climate change and a species’ response Climate change ?
- Climate change and a community’s response
- Climate change and a community’s response
- Climate change and a community’s response Climate change
- Climate change and a community’s response Climate change
- Climate change and a community’s response Climate change ?
- How do host and parasite migration patterns compare? What host life history characters act as constraints?
- How do host and parasite migration patterns compare? What host life history characters act as constraints? Host = American beech, Fagus grandifolia Parasite = Beechdrop, Epifagus virginiana Host density effects
- The parasite: Epifagus virginiana DL Nickrent Obligate parasite Non-photosynthetic Host specific to Fagus grandifolia Annual Selfer EA Saulys
- Two host migration scenarios 13 kybp 9 kybp 6 kybp Host fossil pollen Davis 1983, Bennett 1985, Delcourt and Delcourt 1987, Williams et al. 2004
- Two host migration scenarios Host cpDNA McLachlan et al. 2005 13 kybp 9 kybp 6 kybp PP Prairie Peninsula
- Two host migration scenarios Host fossil pollen Davis 1983, Bennett 1985, Delcourt and Delcourt 1987, Williams et al. 2004 Host cpDNA McLachlan et al. 2005 PP 13 kybp 9 kybp 6 kybp
- Two host migration scenarios Host fossil pollen Host cpDNA PP 13 kybp 9 kybp 6 kybp High density forest development Initial range expansion
- What limits parasite colonization of a new area? Host fossil pollen = host density Host cpDNA = host disperal PP 13 kybp 9 kybp 6 kybp
- Methods: Building a parasite dataset 1064 specimens 95 populations 1016 cpDNA bp 557 bp clpP1 intron 459 bp rbcL pseudogene 47 substitutions 41 haplotypes 4 haplotype groups
- Parasite haplotype distributions PP 13 kybp 9 kybp 6 kybp
- Many genetic breaks in the South Monmonier’s analysis: Manni et al. 2004, Miller 2005, Jombart 2008
- Many genetic breaks in the South - Supported by cross validation analysis
- Migration into the Midwest Probability Migration rate 0.005 0.015 0.025 1 100 0.01 PP PP 13 kybp 9 kybp 6 kybp 13 kybp 9 kybp Hey and Nielsen 2007
- Broad-scale story X Host density matters
- But where are the actual migration corridors?
- Locating migration corridors Landscape connectivity - McRae et al. 2008
- Spatial models with all datasets Parasite cpDNA ~ Host pollen age + Host cpDNA
- Climate change and a community’s response Climate change ?
- Climate change and a community’s response Climate change ?
- Acknowledgements Specimen collectors: Yi-Show Tsai Ross McCauley Chuck Williams Fritz Gerhardt Gelyn Kline Jason McLachlan John Freudenstein Maggie Whitson Paul Manos Mark Fishbein Dan Nickrent Heather Nickrent Philip Hyatt Robyn Burnham Sally Gerhardt Sasa Stefanovic Alison Colwell Erin Tripp Jordan Metzgar Jackson Fox Funding sources: NSF, Sigma Xi, Duke Grad School, Duke Dept. of Biology, ASPT, Mellon Foundation, AWIS, GWIS, Deep Time, Google, NESCent Lab/Theory help: Billy Schnackel Amos Little Jason McLachlan Sang-Hun Oh Norm Douglas Dylan O. Burge Erin Tripp Taina Price Dudu Meireles James Beck Christy Henzler Lisa Pokorny Michelle Hersh Sara Chun Advisor: Paul Manos
- Questions? [email_address] www.duke.edu/~yet2/ phylogeoviz.org