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 presented 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
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: December 15, 2019