Lognormal distribution and power law behavior on self-similar tree branching structure

2014 Fiscal Year Final Research Report

• Project/Area Number: 25891001
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Ecology/Environment
• Research Institution: Obihiro University of Agriculture and Veterinary Medicine
• Principal Investigator: KOYAMA Kohei 帯広畜産大学, 畜産学部, 助教 (70709170)
• Project Period (FY): 2013-08-30 – 2015-03-31
• Keywords: フラクタル

Outline of Final Research Achievements

Simple relationships often characterize complex systems. Lognormal distributions are widely recognized in many fields, including biology, physics, social science, and economics. Despite the fact that a mathematical model of lognormality has long been accepted (“the law of proportionate effect” proposed by Robert Gibrat in 1930), there has been no empirical evidence for this mechanism in biological systems. Our results showed empirically that the sizes of terminal twigs were lognormally distributed on elm tree branches, and that the lognormality was caused by the law of proportionate effects on a self-similar (fractal) branching structure.

Free Research Field

植物生態学