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23,425,000 Yen (FY 1998; 7,411,000 Yen)
Organisms in a coevolutionarily developed species interaction is prone to go extinct in case partner organisms are damaged or lost due to habitat change or invader organisms. We investigated pollination and seed set of heterostylous plants, Primula sieboldii E. Morren and Persicaria japonica (Meisn.) H. Gross in their natural habitats in fragmented landscape and demonstrated 'fruitless falls' i.e., limited fruit and seed set due to insufficient pollinator services or genet iolation, in these species.
On oceanic and continental islands in Japan, we surveyed ( I ) flowering phenology, (2) anthophilous insect community. On the Bonin (Ogasawara) Islands, impact of introduced honeybees upon native bee communities was studied.
Allozyme variation of European and Japanese bumblebees was investigated in order to develop a reliable genetic marker for monitoring the hybridisation between them in the field. We analysed mathematically (1) mutualism between figs and their pollinator wasps, (2) competition between related species of lady beetles, and (3) a system of one predator and two preys, and showed the importance of species interaction on processes of extinction of wild populations,
The social structure of ants compared among three environments: natural forests, secondary forests and open lands. In natural forests monogynous ants including the majority of endemic species were dominant, while polygynous and polydomous tramp species in disturbed habitats. This pattern was consistent across the different climate regions, i.e.Java and Okinawa.
habitat fragmentation, symbiosis, invasion, hybridisation