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Title  :  Mathematical and Biological Considerations on Yield and CompetitionDensity Effects in Selfthinning Plant Populations 
Authors  :  Hagihara, Akio 
Authors alternative  :  萩原, 秋男 
Issue Date  :  Sep1998 
Abstract  :  A mathematical model for describing the density effect occurring in selfthinning
populations is developed on the basis of the following three basic assumptions: (1)
the growth of yield follows the general logistic equation; (2) final yield becomes
constant irrespective of initial density; and (3) there exists a functional relationship
between actual and initial densities. The resultant equation takes the same reciprocal form as the reciprocal equation derived from ShinozakiKira's theory, i.e., the
logistic theory of the CD effect, which deals with the density effect occurring in nonselfthinning populations. It is, however, recognized that one of the two coefficients is quite different in mathematical interpretation between the two reciprocal
equations based on the present theory and the logistic theory of the CD effect, respectively. The present conclusion is consistent with the empirical facts that the reciprocal relationship between yield (or mean phytomass) and density is discernible
in not only nonselfthinning populations, but also selfthinning populations. The
present model is expected to systematically interpret underlying mechanisms be
tween the density effect, which is observed at a time constant among populations
varying in initial density, and selfthinning, which is observed along a time continuum in any given population. 
Type Local  :  紀要論文 
ISSN  :  02869640 
Publisher  :  琉球大学理学部 
URI  :  http://hdl.handle.net/20.500.12000/11817 
Citation  :  琉球大学理学部紀要 = Bulletin of the College of Science. University of the Ryukyus no.66 p.71 79 
Appears in Collections  :  No.66 (1998/9)

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