PE EIE[R-Rg RESEARCH ON - HJ Andrews Experimental Forest

Table 3.-Predicted plant response indices for 25 forest ecosystems based on th e
inclusive limits of species present with known ecological distributions '
Forest type 2
Stand
PT , PT, T/PT , T/PT , PMS , PMS, TGI , TGI , Soi l
maxi - mini- maxi - mini- maxi - mini- maxi- mini - tolermum
mum mum mum mum mum mum mum anc e
Black oak 3 21 .4 17 .7 0 .29 0 .29 25 .4 25 .4 98 95 1
Black oak 21 3 21 .4 17 .7 .29 .29 25 .4 25 .4 96 95 1
Ponderosa pine 8 21 .4 17 .7 .42 .40 20 .3 20 .3 96 90 1
Ponderosa pine 12 3 16 .8 13 .5 .62 .46 19 .1 12 .6 70 68 1
Mixed conifer 1 13 .5 13 .5 .62 .51 15 .3 5 .2 75 68 2
Mixed conifer 11 16 .8 13 .5 1 .00 .57 15 .3 5 .2 70 68 1
Mixed conifer 13 13 .1 12 .2 1 .00 .63 12 .8 8 .4 80 68 1
Mixed conifer 19 13 .1 12 .2 1 .00 .63 12 .8 5 .2 84 68 2
White fir 2 12 .5 12 .2 .62 .51 15 .3 12 .6 65 50 1
White fir 9 12 .5 12 .2 .63 .57 16 .2 12 .8 59 60 2
White fir 14 3 13 .1 11 .0 1 .00 .63 12 .8 8 .4 70 52 2
White fir 22 3 13 .1 10 .3 .62 .63 12 .8 5 .2 70 52 2
Shasta red fir 7 3 7 .8 7 .8 1 .00 .98 5 .2 5 .2 45 45 2
Shasta red fir 16 12.5 7 .5 1 .00 .51 15 .3 5 .2 59 40 1
Shasta red fir 17 7 .8 7 .8 1 .00 .98 5 .2 5 .2 45 45 2
Mountain hemlock 6 7 .8 7 .5 1 .00 .98 5 .2 5 .2 45 35 2
Mountain hemlock 15 3 11 .0 7 .5 1 .00 .46 19 .1 5 .2 59 34 2
Mountain hemlock 18 3 7 .8 7 .5 .62 .46 19 .1 12 .6 40 35 2
Mountain hemlock 24 3 7 .8 7 .8 1 .00 .98 5 .2 5 .2 45 44 2
Jeffrey pine 4 16 .8 12 .7 .61 .51 15 .3 12 .6 70 52 3
Jeffrey pine 5 19 .5 12 .7 .40 .40 18 .1 12 .6 70 52 3
Jeffrey pine 25 3 19.5 12 .7 .61 .51 15 .3 8 .4 70 52 3
Yew 20 3 17 .7 16 .8 .51 .42 16 .2 15 .0 85 80 2
Engelmann spruce 23 11 .0 11 .0 .63 .63 12 .8 12 .8 47 47 2
Brewer spruce 10 10.3 7 .8 .62 .46 19 .1 12 .8 50 50 2
' Potential transpiration (PT) is calculated for April through September based on a minimum stomatal resistance of 4 sec
cm^1 . Transpiration expressed in cm- 2
The ratio or simulated transpiration (T) to potential (PT) reflects the degree of stomata] control exhibited by a referenc e
conifer.
Plant Moisture Stress (PMS) is expressed in atm and represents predawn measurements on reference conifers near the en d
of the summer dry season (Sept .) .
A Temperature Growth Index (TGI) reflects the potential for Douglas-fir seedling growth as a function of air and soil
temperature for the entire growing season .
The soil tolerance index indicates whether the species is exclusively restricted (class 3), tolerant (class 1), or excluded (clas s
2) from infertile ultrabasic soils .
2 From R . H . Waring, Forest plants of the eastern Siskiyous : their environmental and vegetational distribution. Northwes t
Sci . 43 : 1-17, 1969 .
'Simulation of PT and T/PT was not possible because of inadequate data . The predicted values appear reasonable whe n
compared with other stands with similar vegetation, temperature, and plant moisture stress indices .
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