Stand Density Index

Stand density index (SDI) is a relative measure of stand density the converts a stand's current density into a density at a reference size. Stand density index was present by Reineke (1933) and can be defined as:

$$ SDI = TPA \left[ \frac{\bar{D}_q}{10} \right]^{1.605} $$

$$ SDI = TPHA \left[ \frac{\bar{D}_q}{25} \right]^{1.605} $$

where SDI is Stand Density index, Dq is the quadratic mean diameter. Quadratic mean diameter is the diameter of average basal area per tree. A number of maximum stand density indices have been proposed for various species. Table 1 list these stand density indices by species and source.

Table 1. Suggested Maximum SDI by species and source. English units are number of
10-inch trees per acre. Metric units are number of 25.5cm trees per hectare.

Species Maximum SDI
(English)
Maximum SDI
(metric)
Source
White fir
830
2050
Reineke, 1933
Red fir
1000
2470
Reineke, 1933
Mixed conifer for CA
750
1850
Reineke, 1933
Douglas-fir for WA-OR
595
1470
Reineke, 1933
Douglas-fir for CA
600
1480
Reineke, 1933
Eucalyptus
490
1210
Reineke, 1933
European Beech
358
885
Pertzsch & Biber, 2005
Redwood
1000
2470
Reineke, 1933
Ponderosa Pine
800
1980
Reineke, 1933
Loblolly Pine
450
1110
Reineke, 1933
Longleaf Pine
400
990
Reineke, 1933
Norway spruce - Austria
372
920
Steba, 1987
Norway spruce - Germany
564
1395
Pretzsch & Biber, 2005
Norway spruce - Italy
559
1380
Castagneri, 2008
Norway spruce - Austria
780
1927
Monserud et al., 2005
Scots pine - Austria
466
1152
Monserud et al., 2005
Scots pine - Italy
583
1440
Vacchiano et al., 2008
Slash Pine
400
990
Reineke, 1933
Slash Pine
450
1110
Dean and Jokela, 1992
Shortleaf Pine
400
990
Reineke, 1933
Upland Oak
230
570
Schnur, 1937
Ponderosa Pine
830
2050
Long, 1985
Lodgepole pine
690
1700
Long, 1985
Douglas-fir
587
1450
Long, 1985
Western Hemlock
790
1950
Long, 1985
Teak
480
1200
Kumar et al., 1995

References

Castagneri, D., Vacchiano, G., Lingua, E., & Motta, R. 2008. Analysis of intraspecific competition in two subalpine Norway spruce (Picea abies (L.) Karst.) stands in Paneveggio (Trento, Italy). Forest Ecology and Management, 255(3), 651-659.

Dean, T. J. and, E. J. Jokela 1992. A density-management diagram for slash pine plantations in the lower coastal plain. Southern Journal of Applied Forestry 16:178-185.

Kumar B. M. , J. N. Long, and P. Kumar. 1995. Density-Management diagram for teak plantaions of Kerala in peninsular India. Forest Ecology and Management 74:125-131.

Long, J. N. 1985. A practical approach to density management. Forest Chronicle 61:23-37.

Monserud, R. A., Ledermann, T., & Sterba, H. 2004. Are self-thinning constraints needed in a tree-specific mortality model?. Forest Science, 50(6), 848-858.

Pretzsch, H., & Biber, P. 2005. A re-evaluation of Reineke's rule and stand density index. Forest Science, 51(4), 304-320.

Reineke, L. H. 1933. Perfecting a stand density index for even-aged forests. Journal of Agricultural Research 46(7):627-638.

Schnur, G. L. 1937. Yield, stand, and volume tables for even-aged upland oak forests. USDA Technical Bulletin No. 560, 87p.


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Natural Resources Biometrics by David R. Larsen is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License .

Author: Dr. David R. Larsen
Created: July 11, 2001
Last Updated: January 19, 2017