COMPUTER SIMULATION OF BRANCH INTERACTION AND REGULATION BY UNEQUAL FLOW RATES IN BOTANICAL TREES

摘要: Two aspects of branch interaction in trees are investigated theoretically. In the first it is assumed that there a controlling factor which proximity neighboring terminal units influences their branching capability. The almost horizontal tiers lateral branches Terminalia catappa L. and Cornus alternifolia simulated by computer using values based on measured geometries real trees. For interaction, we assume circle inhibition whose center existing point branch. If end another extends into circle, original fails to bifurcate. Examples patterns illustrated different degrees interference compared with T. catappa. second model ability unit bifurcate considered be determined accumulation critical amount hypothetical growthor bifurcation-determining factor. daughter bifurcation have differing "flow rates,' i.e., distributed amounts between axes. Some generated this very similar found an unnamed species Tabernaemontana. both simulations ratios shown variable, not fixed, property A TREE can regarded conceptually as system axes develops process repeated or bifurcation. botanical frequency never same at every Thus, number does increase regular exponent (2N) since rate increment normally decreases. simplest analysis, decrease attributed two theoretical constraints growth: 1) environmental exogenous factor, resulting inter-branch (inter-meristem) competition such actual permanent falls increasing age result abortion abscission young old branches, 2) intrinsic endogenous 1 Received for publication 18 April 1980; revision accepted 2 August 1980. main part present work was carried out during stay H. Honda Harvard Forest research fellow Charles Bullard Fund University. Additional support provided Atkins Garden Cabot Foundation contribution J. B. Fisher supported NSF grants DEB77-13953 79-14635. Acknowledgement due Mmes. D. R. Smith (Harvard Forest), M. HayashiOkuda, Kondo, Misses K. Fukuda, Noda, Tanaka, Y. Ueura (Kanebo Institute Cancer Research) assistance. Permanent address: Kanebo Research, Misakicho 1-91, Kobe 652, Japan. from one mother differentiate kinds bifurcates less frequently than other. This fundamental difference explained us theoretically flow rates through pairs. paper will investigate tree simulation. parameter used obtained three trees, alternifolia, Tabernaemontana sp. Results analyzed terms value allow some comparison These indices been widely applied systems, but show they limited usefulness understanding Computer simulation has quite simple algorithms may generate three-dimensional closely resemble (Honda, 1971). method, therefore, offers techniques investigating developmental rules govern form and, varying chosen parameters time, gives insight adaptive nature form. influence variations normal processes thus preliminary content downloaded 157.55.39.195 Tue, 26 Apr 2016 05:54:56 UTC All use subject http://about.jstor.org/terms 570 AMERICAN JOURNAL OF BOTANY [Vol. 68