著者
Tamura Noriko Shibasaki Eiko
出版者
一般社団法人日本森林学会
雑誌
Journal of forest research (ISSN:13416979)
巻号頁・発行日
vol.1, no.4, pp.219-222, 1996-11-16
被引用文献数
14

Walnut seeds (Juglans ailanthiforia Carr.) hoarded by Japanese squirrels (Sciurus lis Temminck) were tracked using miniature radio transmitters. A total of 100 seeds with transmitters were provided on the feeding stands in the walnut forest from September to December, 1992. Squirrels ate 35 seeds without hoarding, and 60 were scatter-hoarded. Five seeds were eaten by wood mice (Apodemus speciosus Temminck). The distance from the feeding stand to cache sites ranged from 1 to 62 m with the mean 18 m. Of 60 hoarded seeds, 38 were retrieved by squirrels later, but 15 were stolen by wood mice. After all, 7 seeds were not retrieved until May 1993.
著者
Takeuchi Toshikazu Sugaya Takashi Kanazashi Ayako Yoshimaru Hiroshi Katsuta Masaki
出版者
一般社団法人日本森林学会
雑誌
Journal of forest research (ISSN:13416979)
巻号頁・発行日
vol.6, no.3, pp.157-162, 2001-08-16

The genetic diversity of the mangrove tree species Kandelia candel and Bruguiera gymnorrhiza in the Southwest Islands of Japan was investigated. These islands are located at the periphery of the distribution area of the two species, and their populations are relatively small. Allozyme analyses of 17 loci in K. candel and 13 loci in B. gymnorrhiza revealed very little genetic variation in both species. At the species level, the proportion of polymorphic loci wad 4.2%, the average effective number of alleles per locus was 1.02, and the average expected heterozygosity was 0.012 in K. candel. The corresponding figures for B. gymnorrhiza were 9.0%, 1.06 and 0.035, respectively. However, the coefficients of genetic differentiation among the populations were high (G_<ST>=0.165 for K. candel and 0.253 for B. gymnorrhiza). The genetic variation and habitat area of K. candel on Amami Island is greater than on the islands Okinawa and Iriomote. The genetic variation and habitat area of B. gymnorrhiza is greater on Iriomoter Island than on the islands Okinawa and Amami. The level of genetic variation in both of the species might be related to their population sizes.