Loss of Genetic Diversity and Erroneous Phylogeographical Inferences in Lithocarpus Konishii (fagaceae) of Taiwan Caused by the Chi-chi Earthquake: Implications for Conservation1

The effect of natural catastrophic events, such as volcanic eruptions and earthquakes, on the genetic structure of species has been infrequently studied. The 1999 Chi-Chi Earthquake of Taiwan resulted in population extinction of Lithocarpus konishii (Fagaceae), an endangered species, and provides a case study for assessing impacts of natural catastrophes on genetic diversity. Genetic diversity of the atpB-rbcL intergenic spacer of cpDNA and the intron 2 of NADH dehydrogenase subunit 7 gene of mtDNA in L. konishii was determined before and after the earthquake. Loss of rare polymorphisms due to extinction of an entire population at the earthquake epicenter contributed to the reduction of genetic diversity within species in both cpDNA and mtDNA. Star-like phylogenies and significantly negative Tajima’s D statistics suggest a history of recent expansion of the species, which, however, is not confirmed by a nested clade analysis. Phylogeographical inferences were made before and after the earthquake; differences in the phylogeographic analysis suggest that long-range dispersal inferences may be misidentified due to loss of haplotypes and clades in geographical regions of population extinction. Tests of genetic and ecological exchangeability indicate that Lithocarpus populations should be recognized as different conservation units that should be managed separately.