CONCLUSIONS 



A simulator for predicting uneven-aged stand development was constructed and validated 

 for the ponderosa pine/Arizona fescue habitat type of the Southwest. The structure and dynamics 

 of the simulator make it potentially useful for answering even- and uneven-aged management 

 questions. Some results and conclusions formulated during the construction and validation 

 process are: 



1. The distribution of number of trees within 1-inch diameter classes is uniform. 



2. Diameter class basal area growth rates of even- and uneven-aged stands are logically 

 interrelated if the structure of within stand competition is incorporated in the model. 



3. No reasonable log bias correction could be found for the log of basal area growth 

 equations when residuals are not normally distributed. In the case of nonnormality, the 

 development of a calibrating routine is recommended as an alternative to a log bias correction. 



4. Even- and uneven-aged endemic mortality rates can be logically interrelated if cata- 

 strophic mortality is treated in a fashion similar to cutting mortality. 



5. The ingrowth component is the weakest link in the simulator. The development of a 

 regeneration, seedling, and sapling component is highly desirable. 



6. The use of the chi-square statistic for testing "goodness-of-f it" in validation is 

 highly questionable. 



7. The use of regression statistics for testing "goodness-of-f it" in validation did not 

 prove to be very valuable. 



8. The simulation of 2.5-acre subplot values followed by the calculation of their average 

 to obtain mean plot values produced different results than simulating plot averages directly. 

 Because all published uneven-aged stand simulators have used small plots, this result could 

 prove a problem for those interested in simulating plot averages. For the simulator developed 

 in this study, however, analysis also revealed that the difference between the two methods was 

 not too severe. 



PUBLICATIONS CITED 



Adams, Darius M. 



1974. Derivation of optimal management guides: a survey of analytical approaches, in Forest 

 modeling and inventory--selected papers from 1973 and 1974 meetings of midwest mensuration- 

 ists. Dep. For., Sch. Nat. Resour., Coll. Agric. and Life Sci., Univ. Wis., Madison. 

 Adams, Darius M. , and Alan R. Ek. 



1974. Optimizing the management of uneven-aged forest stands. Can. J. For. Res. 4:274-287. 

 Adams, Darius M. , and Alan R. Ek. 



1976. Derivation of optimal management guides for individual stands. In Systems analysis 

 and forest resource management, p. 132-147. Meadows, Bare, Ware, and Row, eds . Soc . Am. 

 For., Washington, D.C. 

 Aigner, Dennis J. 



1972. A note on verification of computer simulation models. Manage. Sci. 18:615-619. 

 Alexander, Robert R. 



1973. Partial cutting in old-growth spruce-fir. USDA For. Serv. Res. Pap. RM-110, 16 p. 

 Rocky Mt . For. and Range Exp. Stn., Fort Collins, Colo. 



Alexander, Robert R. 



1975. Partial cutting in old-growth lodgepole pine. USDA For. Serv. Res. Pap. RM-136, 17 p. 

 Rocky Mt . For. and Range. Exp. Stn., Fort Collins, Colo. 



Alexander, Robert R. , and Carleton B. Edminster. 



1977a. Regulation and control of cut under uneven-aged management. USDA For. Serv. Res. Pap. 

 RM-182, 7 p. Rocky Mt . For. and Range Exp. Stn., Fort Collins, Colo. 



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