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The development of estimation method of extinction probability in population under varying environment

Research Project

Project/Area Number 13640637
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field 生態
Research InstitutionHokkaido Tokai University

Principal Investigator

TAKADA Takenori  Hokkaido Tokai University, International Cultural relationship, Professor, 国際文化学部, 教授 (80206755)

Co-Investigator(Kenkyū-buntansha) OHARA Masashi  Hokkaido University, Graduate school of environmental earth science, Associate Professor, 大学院・地域環境科学研究科, 教授 (90194274)
Project Period (FY) 2001 – 2002
Project Status Completed (Fiscal Year 2002)
Budget Amount *help
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2002: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2001: ¥1,600,000 (Direct Cost: ¥1,600,000)
KeywordsVarying environment / Extinction probability / projection matrix model / population dynamics / 多年生草本 / コンピュータシュミレーション
Research Abstract

We analyzed the popular dynamics of Trillium apetalon and T. camschatcense under varying environment, using the census data during about 15 years. Moreover, we developed a method to check the reliability of elasticity matrix, which is an index of population dynamics, in density-dependent matrix model.
As for the former, we estimated the mean and variance of important life-history parameters (survival rate and fecundity etc.) and examined the effect of temporal variation of those parameters on the expectation of population growth rate. As the result, we obtained the probabilities of increase and decrease of the population and clarified several points; (1) The probability that the population of Trillium apetalon decreases under 30% after 50 years is 75.6%, while the probability that the population of Trillium camschatcense decreases under 30% after 50 years is 0%. (2) In both species, elements with high sensitivity are different from elements that contribute more to the decrease of the population size.
As for the latter, we obtained the theoretical elasticity matrix at equilibrium and the elasticity matrix under actually varying dynamics, and compared them. We found that the discrepancy between them depend largely on the life history pattern and the pattern of density-dependence. In the case of Beverton-Holt-type density dependent function, the discrepancy is relatively small, while in the case of Ricker-type density dependent function, the discrepancy is large. The reliability of elasticity matrix is becoming low when the species in question is monocarpic and delayed growth.

Report

(3 results)
  • 2002 Annual Research Report   Final Research Report Summary
  • 2001 Annual Research Report
  • Research Products

    (14 results)

All Other

All Publications (14 results)

  • [Publications] Ohara, M., Takada, T., Kawano, S.: "The demography and reproductive strategies of a polycarpic perennial, Trillium apetalon (Trilliaceae)"Plant Species Biology. 16. 209-217 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Tomimatsu, H., Ohara, M.: "Effects of forest fragmentation on seed production of the understory herb Trillium camschatcense"Conservation Biology. 16. 1277-1285 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Tomimatsu, H., Ohara, M.: "Genetic diversity and local population structure of fragmented populations of Trillium camschatcense (Trilliaceae)"Biological Conservation. 109. 249-258 (2003)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Caswell, H, Takada, T.: "Elasticity analysis of density-dependent, strix population models : the invasion exponent and its substitutes"Journal of Theoretical Biology. (In press).

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Tomimatsu, H., Ohara, M.: "Floral visitors of Trillium camschatcense (Trilliaceae) in fragmented forests"Plant Species Biology. (In press).

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Tomimatsu, H. and Ohara, M.: "Genetic diversity and local population structure of fragmented populations of Trillium camschatcense (Trilliaveae)"Biological Conservation. 109. 249-258 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Tomimatsu, H. and Ohara, M.: "Effects of forest fragmentation on seed production of the understory herb Trillium camschatcense"Conservation Biology. 16. 1277-1285 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Caswell, H. and Takada, T.: "Elasticity analysis of density-dependent matrix population models: the invasion and its substitute"Journal of Theoretical Biology. (in press).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Tomimatsu, H. and Ohara, M.: "Floral visitors of Trillium camschatcense (Trilliaceae) in fragmented forests"Plant Species Biology. 16. 209-217

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Ohara, M, Takada, T. and Kawano, S.: "The demography and reproductive strategies of a polycarpic perennial, Trillium apetalon (Trilliaceae)"Plant Species Biology. (in press).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Ohara, M., Takada, T., Kawano, S.: "The demography and reproductive strategies of a polycarpic perennial, Trillium apetalon (Trilliaceae)"Plant Species Biology. 16. 209-217 (2001)

    • Related Report
      2002 Annual Research Report
  • [Publications] Tomimatsu, H., Ohara, M.: "Effects of forest fragmentation on seed production of the understory herb Trillium camschatcense"Conservation Biology. 16. 1277-1285 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] Tomimatsu, H., Ohara, M.: "Genetic diversity and local population structure of fragmented populations of Trillium camschatcense (Trilliaceae)"Biological Conservation. 109. 249-258 (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] Caswell, H., Takada, T.: "Elasticity analysis of density-dependent, strix population models : the invasion exponent and its substitutes"Journal of Theoretical Biology. (In press).

    • Related Report
      2002 Annual Research Report

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Published: 2001-04-01   Modified: 2016-04-21  

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