Testing for tectonically-mediated biological disturbance in New Zealand's coastal ecosystems: the phylogeographic effects of prehistoric earthquake uplift
|dc.identifier.citation||Parvizi, E. (2021). Testing for tectonically-mediated biological disturbance in New Zealand’s coastal ecosystems: the phylogeographic effects of prehistoric earthquake uplift (Thesis, Doctor of Philosophy). University of Otago. Retrieved from http://hdl.handle.net/10523/12330||en|
|dc.description.abstract||Recent modeling and laboratory experiments suggest that the distribution of genetic diversity can be highly structured even in the absence of selective forces or physical barriers. Specifically, the colonization process may play a key role in partitioning spatial genetic diversity. In this thesis, I capitalize on a paleoseismic disturbance event on the coast of southeastern New Zealand to assess the genetic legacy of tectonic disruption and post-disturbance colonization. I hypothesized that major tectonic uplift drives genetic turnover, and that first-colonizing lineages will rapidly dominate newly available terrain following disturbance. Observations from recent large-scale earthquakes in New Zealand (e.g., the 2016 Kaikōura earthquake) have shown dramatic loss of intertidal macroalgae, particularly Durvillaea, due to coastal uplift and subsequent exposure to air and desiccation, providing empty intertidal habitats for recolonization. Topographic features and fossil data suggest that the Akatore region southeast of New Zealand also experienced a large-scale coastal uplift event at approximately 800-1000 y BP. Comparisons of COI sequences of D. antarctica inhabiting the historically uplifted coasts with non-uplifted northern and southern populations revealed a clear genetic distinction between uplifted versus non-uplifted regions. SNP data from three co-distributed Durvillaea species that occupy different tidal ranges - from high intertidal to shallow subtidal - showed that post-uplift recolonization generated distinct spatial genomic patterns tightly linked to geological fault boundaries in two intertidal Durvillaea, while the subtidal species remained unaffected. As intertidal Durvillaea are habitat-forming species and support diverse benthic communities, their disruption can affect the recolonization of associated epibiota. Fine-scale SNP data from three epibionts of intertidal Durvillaea revealed concordant phylogeographic breaks and synchronous expansions in intertidal macroalgae and two of their codistributed epibiotic species (including the chiton, Onithochiton neglectus and the isopod, Limnoria segnis), while the third epibiont, the amphipod, Parawaldeckia karaka, showed no evidence of past disturbance. Overall, this study provides insights into the genetic dynamics of populations responding to environmental change, and highlights the enduring biodiversity effects of paleoseismic disturbance.|
|dc.publisher||University of Otago|
|dc.rights||All items in OUR Archive are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.|
|dc.title||Testing for tectonically-mediated biological disturbance in New Zealand's coastal ecosystems: the phylogeographic effects of prehistoric earthquake uplift|
|thesis.degree.name||Doctor of Philosophy|
|thesis.degree.grantor||University of Otago|
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