Kubota Y., Shiono T. & Kusumoto B. (2015) Role of climate and geohistorical factors in driving plant richness patterns and endemicity on the east Asian continental islands. Ecography 38: 639-48.
以下は、F1000 Faculty MemberのLee Frelich博士のコメントです。
Japan is one of 34 plant biodiversity hot spots in the world. This study examined 5614 vascular plant species (more than 1800 of which are endemic to Japan) occurrence in 4852, 10 by 10km grid squares covering the Japanese archipelago.
To analyze patterns of species richness, environmental variables such as elevation, current climate variables (temperature and precipitation), quaternary change in climate and geology, and isolation were obtained for each grid square. Temperature and precipitation were the most important explanatory variables for overall species richness, while elevation, quaternary climate change and distance from the Asian continent explained endemic species richness. There were more endemic species at higher elevation and with greater distance from the Asian continent. Allopatric speciation apparently occurred in isolated mountain areas.
As occurs so often in ecology, detailed data over large geographical expanses reveals that no one theory allows universal explanation of patterns observed in the field. Many ecologists spend much effort trying to show how much variability is explained by a given theory. In contrast, the strategy in this study was to show how different theories related to species richness blend together in myriad ways to explain variability in species richness and endemism in varying geographical settings across the landscape. Furthermore, the relative importance of competing theories for explaining species richness also varied among the taxonomic groups examined — in this case trees, herbs, and ferns.