A Process Model of Cambial Activity and Ring Structure in Conifers Using Daily Climatic Data

by

Alexander V. Shashkin, Institute of Forestry, 660036 Krasnoyarsk, Russia,

Harold C. Fritts

and

Geoffrey M. Downes, CSIRO Division of Forest Products, Private Bag 10, Rosebank, MDC, Clayton, Victoria, AU


TREERING 3.0 is a process model with:

Calculations of:
water balance, photosynthesis, carbon storage, crown growth, and cambial activity calculated at daily time steps.

Inputs of:

daily maximum and minimum temperatures, daily precipitation, and constants (coefficients) for equations governing biophysical processes.
Outputs of:
daily values of growth regulating processes with crown growth, number of cells dividing, enlarging, and maturing along with the resulting ring structure.
Capablility of Iteration:
to optimize values of parameters or constants with uncertain values.


Four Modules Define the Growth Dynamics:

Crown Growth:
a function of bud primordia, changing leaf mass and limiting conditions of temperature, water stress, available carbon.
Cell Division:
a function of 3 linear relationships controlled by crown activity, limiting conditions and number of dividing cells.
Cell Enlargement:
a function of 2 linear relationships controlled by crown activity, limiting conditions, and prior day's enlargement rate.
Wall Thickening:
a function of 2 linear relationships controlled by crown activity, limiting conditions, and prior day's thickening rate.

Daily Rates and States are saved and Plotted


Model Limitations:


Plans for the Future:

To Download Files of the New TreeRing Model 2000 enter "http://tree.ltrr.arizona.edu/webhome/hal/treering/".

To Download Files of the older Modeling Program.

Please Send me Comments, Questions, or Suggestions.

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Prepared by Harold C. Fritts hfritts@LTRR.arizona.edu -- Last updatedMarch 17, 2000