| Summary: | 博士 === 國立臺灣師範大學 === 生命科學研究所 === 96 === The species diversity of Taiwanese Hynobius salamanders has long been debated. In this study, I analyzed morphological and molecular data from these taxonomically problematic salamanders. My results showed that there are five distinct molecular clades of Taiwanese salamanders that match morphological differences and are indicative of specie`s-level recognition. Three species corroborate previous finding, while the other two are described as new species.
The distribution survey of Alishan salamander (Hynobius arisanensis) in Alishan Areas was conducted in 36 forestry areas. We found Alishan salamander in nine of them. Common characters of these localities show a gradual rise slope and with small creeks. Analysis of Hynobius arisanensis microhabitat preferences consisted of two parts: one to record microhabitat use of salamanders, the other one to quantify suitable microhabitat in the study site. Alishan salamanders showed a negative association with rocks, while a positive association with decayed woods. They also like the cover objects of shelters with mosses grown on it. As for substrates, salamanders were found positively to associate with pebbles, and were negatively associated with live plant roots. The Alishan salamander preferred substrates with neutral soil pH, high soil moisture, and suitable soil hardness.
I use the area-constrained method to monitor salamander population dynamic in the Sister Ponds, Chiayi Hsien. I used the Jolly-Seber method to estimate the monthly population size, it ranged between 13 and 305 individuals. It seemed that population size does not decrease as comparing with estimations made by the former researchers. I further used the Cormack-Jolly-Seber model to estimate the survival and capture probability of this population. The survival probabilities for adults and juveniles were 0.996 and 0.997, respectively. Capture probabilities were seasonal-specific, the capture probabilities were significantly positive correlated with rainfalls. Using the population projecting matrix to analyses the population dynamics and to determine population growth rate of this population, it was 1.130, indicating that the population is stable and slow growth. The sensitivity and elasticity of population growth rate both indicate that the adult survival rate was the most important vital rate for the population stability.
In Chapter 5, I use Hynobius arisanensis as a model species to investigate genetic structure of an alpine salamander. AMOVA of three mountain ranges suggested significant genetic differentiation among mountain ranges, among populations within mountain ranges, and within populations. Mismatch distribution analysis showed that populations within Alishan range exhibited a pattern of demographic expansion. Nested clade analysis indicated that study populations showed restricted gene flow or allpartic fragmentation. I also used Bayesian coalescent approach to estimate the divergence time and to inference their phylogeographic relationships.
|
|---|
