HOME    About this site    mypage    Japanese    library    university    Feedback

University of the Ryukyus Repository >
Faculty of Science >
Bulletin >
Bulletin of the College of Science, University of the Ryukyus >
No.64 (1997/9) >

 
Title :A Note on the Fundamental Equation of Self-Thinning in the Logistic Theory of Plant Growth
Authors :Hagihara, Akio
Authors alternative :萩原, 秋男
Issue Date :Sep-1997
Abstract :The fundamental equation of self-thinning, which was proposed in the logistic theory of plant growth for describing the density effect in self-thinning populations, is based on the following two fundamental assumptions: one is that the growth of mean phytomass w follows a general logistic equation; the other is that the final yield Y(t), which is pre scribed as the product of the asymptote of mean phytomass W(t) and density P , becomes constant irrespective of P , i.e. the law of constant final yield is assumed. In the light of the basic principle of self-thinning that the relative growth rate of mean phytomass (l/u>) (dw/dt) is given by the sum of the relative growth rate of yield (1/y) (dy/dt) and the relative mortality (-1/P) (dP/dt), the first assumption brings to the conclusion that the final yield Y(t) is not prescribed by W{t) P , but is prescribed by(l-tn/A (t))W(t) P (ro, relative mortality; A (f), coefficient of growth), whose value depends on density P except for the special case where both Wit) P and m are independent of P. This inevitable consequence is in conflict with the prescription referring to the final yield Y(t) in the second assumption of the logistic theory of plant growth. As a result, it is suggested that an alternative theory for the density effect in self-thinning populations should be newly constructed to harmonize the assumption referring to the growth of mean phytomass with the assumption referring to the law of constant final yield.
Type Local :紀要論文
ISSN :0286-9640
Publisher :琉球大学理学部
URI :http://hdl.handle.net/20.500.12000/11819
Citation :琉球大学理学部紀要 = Bulletin of the College of Science. University of the Ryukyus no.64 p.69 -76
Appears in Collections:No.64 (1997/9)

Files in This Item:

File Description SizeFormat
No64p069.pdf570KbAdobe PDFView/Open