JAPANESE JOURNAL OF ECOLOGY
Online ISSN : 2424-127X
Print ISSN : 0021-5007
ISSN-L : 0021-5007
Volume 61, Issue 2
Displaying 1-18 of 18 articles from this issue
Original Articles
  • Shinichi Ito, Tomokazu Suzuki, Yohsuke Kominami
    Article type: Article
    2011 Volume 61 Issue 2 Pages 123-131
    Published: July 30, 2011
    Released on J-STAGE: April 21, 2017
    JOURNAL FREE ACCESS
    Land crabs are involved in seed dispersal and seed predation in certain tropical vegetation. However, only a few studies have examined this ecological role of land crabs in temperate regions. This study evaluated the preference of land crabs for fruit and assessed their ability to act as seed dispersers and seed predators. The study included three species of land crab, Chiromantes haematocheir, Sesarmops intermedium, and C. dehaani, that are widely distributed in Japan. Individuals from these crab species exhibited preferences for fruits of 11 plant species. C. dehaani crabs were observed only in wet vegetation; they fed on fruit near the nest and frequently destroyed seeds. Therefore, C. dehaani seems to be a seed predator rather than a seed disperser. C. haematocheir crabs were observed near different kinds of vegetation; they often carried fruit away from the nest and destroyed seeds only to a limited extent. This suggests that C. haematocheir contributes to the seed dispersal of many species. In comparison with the other two species, S. intermedium crabs were found to exhibit intermediate traits. In temperate coastal forests, each species of land crab may affect seed survival and dispersal in a different manner.
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Review
  • Aki Mizuguti, Takashi Nagai, Motoaki Asai, Hiroaki Ikeda
    Article type: Article
    2011 Volume 61 Issue 2 Pages 133-153
    Published: July 30, 2011
    Released on J-STAGE: April 21, 2017
    JOURNAL FREE ACCESS
    The integrated assessment of ecological risks in farmland was examined by examining the overall connections between the individual risk assessments of pesticides, genetically modified (GM) crops, and weed control. For pesticides, the ecological risks in aquatic ecosystems are assessed using the predicted environmental concentrations of focal pesticides and their acute toxicities to legal test organisms. For GM crops, the ecological risks around farmlands and transportation routes are evaluated based on the substantial equivalence of GM crops to their parental lines. For weed control, management practices are determined mainly by economic acceptance based on weed abundance in and around farmlands, and ecological risks are not addressed at present. Therefore, there is little overlap in assessment items across the three risk factors, and so it seems difficult to integrate the ecological risks by adding the individual assessment results. In order to integrate different risk factors, cost-benefit analyses and multi-criteria decision analyses are often used. However, these analyses have both merits and demerits. For application to decision-making at the field level, it is necessary to set common goals by way of "backcasting" and to integrate risk assessments based on agricultural management practices.
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Feature Process of ecosystem recovery after the 2000 year eruption on Miyake-jima Island
From field research sites (18)
Museum and Ecology (16)
An introduction to ecogenomics (6)
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