1. General Model Information
Name: A Process Model of Cambial Activity and Ring Structure in Conifers
Main medium: terrestrial
Main subject: forestry
Organization level: organism, ecosystem
Type of model: not specified
Main application: research
Keywords: dendrochronology, tree ring, cambial activity, wood structure, conifer, crown, physiology
Harold C. Fritts
Lab. of Tree-Ring Research
5703 North Lady Lane
Tucson, AZ 85704-3905,
Phone & Fax: (520) 887 7291
Inputs of daily precipitation and temperature are used to simulate water balance,
stomatal activity, photosynthesis, carbon storage, crown growth and cambial activity
(cell division, enlargement and maturation). The model is applied to
dendrochronologically dated conifers that have been limited by variations in moisture or
temperature so that actual measurements of ring structure, cell size and wall thicknesses,
can be used to validate the model simulations.
Growth dynamics of trees are calculated using modules of crown growth, cell division,
cell enlargement, and wall thickening in dependence on environmental conditions.
Additional information can be found on TREERING´s home page .
II. Technical Information
Operating System(s): DOS
Programming Language(s): Demonstration Disk with executables is available from Harold C. Fritts here . or FTP: ftp.ltrr.arizona.edu directory: /sys/home/anonymou/pub/trdemo
Might be downloaded from here .
Input data needed:
Output data are
- Daily maximum and minimum temperature
Also iteration routines to optimize individual uncertain parameters are available.
- Plots and tables of processes
- conditions and cell features
- comparitive statistics between estimates and cell measurements
III. Mathematical Information
Shashkin, A. V. and H. C. Fritts. 1995.
Preliminary Draft. TREERING 2.0: A process model simulating cambial activity and ring structure in conifers using daily climatic data. 43 pp.
Fritts, H.C. and A. V. Shashkin. 1995.
Modeling tree-ring structure as related to temperature, precipitation and day length. In: Lewis, T.E. ed. "Tree rings as Indicators of Ecosystem Health." CRC Press, Boca Raton, USA. Chapter 2, pp. 17-57.
Fritts, H.C., E.A. Vaganov, I.V. Sviderskaya and A.V. Shashkin. 1991.
Climatic variation and tree-ring structure in conifers: Empirical and mechanistic models of tree-ring width, number of cells, cell size, cell-wall thickness and wood density. Climate Research 1:97-116.
V. Further information in the World-Wide-Web
TREERING Home Page
VI. Additional remarks
Harald C. Fritts plans:
Will be developing the cambial portions of the model to describe more species, variations in the entire tree, and other anatomical features. Would like to collaborate using more sophisticated physiological models for tree processes and concentrate our efforts on simulating cambial activity and the development of ring structure including biomass, density, geochemistry of wood structure.
Last review of this document by: November, 21th 1997 M.Sonntag and T. Gabele
Status of the document:
last modified by
Tobias Gabele Wed Aug 21 21:44:51 CEST 2002