1. General Model Information

Name: A forest model based on tree morphology and physiology

Acronym: AMORPHYS

Main medium: terrestrial
Main subject: forestry
Organization level: biocoenosis
Type of model: not specified
Main application: decision support/expert system, research
Keywords: object-oriented, forest model, silviculture, climatic and atmospheric conditions, loblolly pine, natural spruce, fir

Contact:

Harry T. Valentine
NE - Durham
Porject 4104
USDA Forest Service
Northeastern Research Station
P.O. Box 640
Durham, NH 03824

Phone: +603 868 7671
Fax: +603 868 7604
email: valentine@fs.fed.us
Homepage: http://www.fs.fed.us/ne/durham/

Author(s):

Abstract:

AMORPHYS is computerized forest model, written in object-oriented code, that runs under Windows 95 or NT. It is designed to estimate the growth and development of trees in an even-aged stand under (i) the application of intensive silviculture (e.g., thinning, pruning, irrigation) and (ii) varying climatic and atmospheric conditions.

To use AMORPHYS, one needs to specify the species, locations, and initial key dimensions of model trees that occupy a plot and plot buffer. This information may be generated within AMORPHYS, supplied from a file, or entered in AMORPHYS's spreadsheet. Unentered key dimensions of the model trees, other than diameter, are automatically estimated. Diameter ordinarily is measured at a height of 0.1 m on a short tree or at 1.37 m if the base of the live crown has risen to that height or greater.

The growth and development of model trees are projected on an annual basis. The morphological dimensions of each model tree are constrained to accord with pipe-model theory. Annual changes in the dimensions (and components of dry matter) of each model tree are estimated with submodels that track carbon assimilation and allocation, crown-rise, and senescence. Responses by a model tree to irrigation, climate, and the increasing atmospheric concentration of carbon dioxide are effected through the assimilation and allocation submodel. Responses to crowding (and thinning and pruning) are effected mechanistically through the crown-rise submodel. Three-dimensional snapshots of the development of the stand at different points in time are rendered through a "stand visualization system."

AMORPHYS estimates a large suite of variables of interest to foresters and ecologists, the latter including net primary productivity and annual production of litter and coarse woody debris. AMORPHYS has been calibrated for loblolly pine plantations in Virginia and North Carolina. Calibration of the model for natural spruce and fir forests in Maine is ongoing.

Source of abstract:
NE - Durham - NH (Project 4104): http://www.fs.fed.us/ne/durham/

II. Technical Information

II.1 Executables:

Operating System(s): Windows 95, NT

II.2 Source-code:

Programming Language(s):

II.3 Manuals:

II.4 Data:

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

III.2.1 Input

III.2.2 Output

IV. References

Height growth, site index, and carbon metabolism. Silva Fennica 31(3):251-263 (1997). Valentine, H.T.
Bayesian Analysis of the linear model with heterogeneous variance. Forest Science 44(1):134-138 (1997). Green, E.J. and H.T. Valentine.
Projections of growth of a loblolly pine stand under elevated temperatures and carbon dioxide. pp 341-352. In: The Productivity and Sustainability of Southern Forest Ecosystems in a Changing Environment. Edited by R.A. Mickler and S. Fox. Springer-Verlag, Ecological Studies Series 128, (1998). Valentine, H.T., T.G. Gregoire, H.E. Burkhart, and D.Y. Hollinger.
Composite and calibration estimation of 3P sampling. Forest Science 45(2):179-185 (1999). Gregoire, T.G. and H.T. Valentine.
Seasonal patterns and environmental control of carbon dioxide and water vapor in an ecotonal boreal forest. Global Change Biology 5(8):891-902 (1999). Hollinger, D.Y., S.M. Goltz, E.A. Davidson, T.J. Lee, K.Tu, and H.T. Valentine.
Projecting the growth of loblolly pine in a changing atmosphere. Southern Journal of Applied Research 23(4):212-216 (1999). Valentine, H.T., R.L. Amateis, H.E. Burkhart, T.G. Gregoire, D.Y. Hollinger and D.W. MacFarlane.
Estimation of net primary productivity of even-aged stands with carbon-allocation models. Ecological Modelling 122(3):139-149 (1999). Valentine, H.T.
Assessing uncertainty in a stand growth model by Bayesian synthesis. Forest Science 45(4):528-538 (1999). Green, E.J., D.W. MacFarlane, H.T. Valentine, and W.E. Strawderman.
Initializing a model stand for process-based projection. Tree Physiology 20:393-398 (2000). Valentine, H.T., D.H. Herman, J.H. Gove, D.Y. Hollinger, and D.S. Solomon.
A field test of cut-off importance sampling of bole volume. (In press, proceedings of the 1998 Boise Inventory Conference.) Gove, J.H, H.T. Valentine and M.J. Holmes.
Assessing uncertainty in mechanistic models. (In press, proceedings of the 1998 Boise Inventory Conference.) Green, E.J., D.W. MacFarlane and H.T. Valentine.

V. Further information in the World-Wide-Web

USDA Forest Service, NE - Durham: http://www.fs.fed.us/ne/durham/
Article Summary: Tree Physiology, 20:393-398 (2000) http://www.heronpublishing.com/tree/files/domain/data/contents/summary/a20-393.html

VI. Additional remarks

Last review of this document by:
Status of the document: Juergen Bierwirth, 22.01.2001
last modified by Tobias Gabele Wed Aug 21 21:44:39 CEST 2002