近畿地方における照葉樹林主要構成種の地理的分布, 特に後氷期の分布拡大について

抄録

Results obtained from pollen analysis revealed the geographical distribution of the main lucidophyllous species in the Kinki district to be strongly affected not only by the present climatic conditions but also by climatic changes during the postglacial period. It was assumed that the immigration of lucidophyllous species into the central part of the Kinki district occurred through the Kii Peninsula route. Both the Kako-Yura route and the Japan Sea route played an important role in the immigration of these species into the Wakasa district during the Hypsithermal period. 1. The geographical distribution of the main lucidophyllous species in the Kinki district was studied in relation with the present climatic conditions and the climatic changes during the postglacial period. 2. The lucidophyllous species in the district were classified into eight types according to their geographical distribution patterns. The distribution of Myrica rubra type and Elaeocarpus sylvestri var. ellipticus are influenced strongly by the coldness in winter. The snowfall condition is more closely related to the distribution of Ardisia crenata type and photinia glabra type and Epimedium grandiflorum ssp. sempervirens than the other factors. The distribution types of Persea thunbergii and the Daphniphyllum teijsmannii are correlated with annual precipitation and the condition of sea wind with salt, respectively. 3. It is presumed that there are four immigration routes of the species into the Kinki district during the postglacial period, i.e. the Kii Peninsula route, the Pacific route, the Setouchi route and the Japan Sea route. The main route of the species into the central part of the Kinki district seems to be the Kii Peninsula route. 4. The lucidophyllous species immigrated into the Wakasa district through the Kako-Yura route and the Japan Sea route. The geographic isolation of Myrica rubra group in the Wakasa district seems to result from the immigration during the Hypsithermal period and the extinction in the adjacent area during the later cool period. The distribution of the species are controlled also by condition of historical phytogeography due to the climatic changes duringthe postglacial period.