1990 Fiscal Year Final Research Report Summary
Resource Utilization and Coevolution of Seed Insect Predators
| Project/Area Number |
01540555
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
生態学
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| Research Institution | Shiga Prefecturaljunior College |
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Principal Investigator |
OHGUSHI T Fac. Agri,. Shiga Phiga Prefec. Jr. Col. Assoc. Prof., 農業部, 助教授 (10203746)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Seed / Predation / Coevolution / Defensive strategy / Resource utilization / Species interactions |
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| Research Abstract |
I argue the ecological and evolutionary implications of biological interactions in a seed-predator system, based on the study on acorn insect predation. Also, I expand an alternative approach to a more exact understanding of insect-plant interactions.
Seeds provide highly nutritive food supply to a wide variety of animals. It is not surprising to find that many seeds may be lost to predators before ripening. It should be noted that seed predation will control the population when it reduces the seed in a density dependent manner. However, if the predator differentiates between genotypes, It will act as a selective forces.
There are several means which plants could employ to reduce seed loss to insect predators during the predisporsal phase. In addititon to morphological and chemical defenses, there are some other evasion tactics. One is to modify the flowering period to escape the predator. Another tactic is simply the reduction of flower size, by reducing foraging efficiency.
Effective strategy especially in forest trees is masting : the production of large crops of seeds at long intervals. In a mast year the predators are satiated by a surplus of food, and seed survive to establish seedlings will be high. In the lean years the predator population is reduced, and may be unable to build up quickly. An essential feature of this strategy is that all the trees in one area which share the same predator should synchronize their masting cycle. Any individual tree which masted in a generally non-mast year would be subjected to the exclusive attention of the seed predators. Synchron may be achieved by a genetically fixed, shared response to some environmental cue, such as a given set of weather conditions which occur at the appropriate frequency. The intervals between large seed crops are mostly in the two to four year range.
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Research Products
(5 results)
