Table 1 — Scientific name, common name, abbreviation, and minimum establishment height for 

 regeneration. Species are listed in approximate order of increasing shade tolerance. 

 This order will be maintained in tables that provide equations by species 



Prognosis 

 Model Minimum 

 Scientific name Common name abbreviation height 



Feet 



Pinus ponderosa Dougl. 

 ex Laws. var. 

 ponderosa 



ponderosa pine 



PP 



1.0 



Larix occidentalis 

 Nutt. 



western larch 



L 



1.0 



Pinus contorta Dougl. 

 ex Loud. 



lodgepole pine 



LP 



1.0 



Picea engelmannii 

 Parry ex Engelm. 



Engelmann spruce 



S 



.5 



Pseudotsuga menziesii 

 var. glauca (Beissn.) 

 Franco 



Douglas-fir 



DF 



1.0 



Pinus monticola Dougl. 

 ex D. Don 



western white pine 



WP 



1.0 



Abies grandis (Dougl. 

 ex D. Don) Lindl. 



grand fir 



GF 



.5 



Tsuga heterophiyila 

 (Raf.) Sarg. 



western hemlock 



WH 



.5 



Abies lasiocarpa 

 (Hook.) Nutt. 



subalpine fir 



AF 



.5 



Thuja plicata Donn ex 

 D. Don 



western redcedar 



C 



.5 



The presence of shrubs, forbs, and grasses was recorded on each Vsoo-acre 

 plot. Each species was characterized by recording average height and per- 

 centage of the plot area covered by a vertical projection of the crown on the 

 ground. Coverage could exceed 100 percent because of overlapping layers 

 of shrubs, forbs, and grasses. These data were not used to predict regenera- 

 tion success because it was not possible to retrospectively determine cover- 

 age at the time of seedling establishment. A model of secondary succession 

 for shrubs, forbs, and grasses has been developed using the Idaho data 

 (Moeur 1985). 



MODELmG TECHNIQUE 



The technique for developing equations follows the example of Hamilton and 

 Brickell (1983) for two-state systems. Each plot in the sample is in one of 

 two states: stocked with at least one established seedling or nonstocked. All 

 plots are used to develop equations predicting the probability of a plot being 

 stocked. Then, only stocked plots are used to estimate the number of trees 

 on the plot, number of species, species composition, and seedling heights. 



The probability of stocking t years after disturbance is estimated by a logistic 

 equation (Hamilton 1974) within the interval [0,1]. After the attributes of 



5 



