Comparison of Stand Density Measures as Predictor of Diameter Increment

Öz

Seven expressions of stand density were compared in regard to overstory tree diameter increment in eastern cottonwood (Populus deltoides Bartram ex Marsh.)-silver maple (Acer saccharinum L.)-American sycamore (Platanus occidentalis L.) forests. Basal area (BA), trees per hectare (TPH), percent stocking, stand density index (SDI), relative minimum density of full site occupancy (R_MDFO), percent average maximum density (P_AMD) and relative density (RD) were evaluated as expressions of stand density. Relative stand density measures seemed to be better predictors of average diameter increment than absolute density measures. In addition, relative density measures were identical in regard to their influence on the tree diameter increment.

Anahtar Kelimeler

• absolute measures,basal area,relative measures,diameter increment,stocking

Meşcere Sıklığı Ölçü Birimlerinin Çap Büyümesini Tahmin Etme Yönünden Karşılaştırılmaları

Öz

Yedi adet meşcere sıklığı ölçü birimi, Doğu kavağı (Populus deltoides Bartram ex Marsh.)-gümüşi akçaağaç (Acer saccharinum L.)-Amerikan çınarı (Platanus occidentalis L.) ormanlarındaki ağaç çap büyümesini tahmin etmeleri yönünden karşılaştırılmıştır. Göğüs yüzeyi alanı (BA), hektardaki ağaç sayısı (TPH), yüzde sıkışıklık, meşcere sıklık indeksi (SDI), tüm alan doluluğunun minimum nispi sıklığı (R_MDFO), ortalama maksimum sıklık yüzdesi (P_AMD) ve nispi sıklık (RD) meşcere sıklığını ifade etmeleri bakımından değerlendirilmiştir. Nispi meşcere sıklık ölçü birimlerinin ağaç çap büyümesini  tahmin etme bakımından mutlak sıklık ölçü birimlerine nazaran daha başarılı oldukları saptanmıştır. Ayrıca, nispi meşcere sıklık ölçü birimlerinin ağaç çap büyümesine olan etkileri bakımından kendi aralarında benzer oldukları tespit edilmiştir.

Anahtar Kelimeler

• absolute measures,basal area,diameter increment,relative measures,stocking

Kaynakça

1. Bring, J. 1994. How to standardize regression coefficients. American Statistician. 48: 209-213.
2. Drew, T.J., and J.W. Flewelling. 1979. Stand density management: an alternative approach and its application to Douglas-fir plantations. For. Sci. 25: 518-532.
3. Ernst, R.L., and W.H. Knapp.1985. Forests stand density and stocking concepts, terms and the use of stocking guides. USDA For. Serv. Gen. Tech. Rep. WO-44. 8 p.
4. Forest Inventory and Analysis National Program. 2011. Available at http://www.fia.fs.fed.us/tools-data/.
5. Gingrich, S.F. 1967. Measuring and evaluating stocking and stand density in upland hardwood forests in the central states. For. Sci. 13: 38-53.
6. Goelz, J.C.G. 1995. A stocking guide for southern bottomland hardwoods. South. J. Appl. For. 19: 103-113.
7. Hox, J.J. 2002. Multilevel analysis: techniques and applications. Lawrence Erlbaurn Associates, Inc. New Jersey, USA. ISBN: 0-8058-3218-1.
8. Jack, S.B., and J.N. Long. 1996. Linkages between silviculture and ecology: an analysis of density management diagrams. For. Ecol. Manage. 86: 205–220.

9. Krajicek, J.E., K.A. Brinkman, and S.F. Gingrich. 1961. Crown competition a measure of density. For. Sci. 7: 35-42.
10. Larsen, D.R., D.C. Dey, and T. Faust. 2010. A stocking diagram for Midwestern eastern cottonwood-silver maple-American sycamore bottomland forests. North. J. Appl. For. 27: 132-139.
11. Lhotka, J.M., and E.F. Loewenstein. 2007. A weighted relative density model applied to loblolly pine (Pinus taeda L.) stands. African Journal of agricultural Research. 2: 300-304.
12. Martin, J. 1996. Wisconsin woodlands: Estimating stocking conditions in your timber stand. Available online at http://learningstore.uwex.edu/assets/pdfs/G3362.PDF.
13. O’Connell, B.M., E.B. Lapoint, J.A. Turner, T. Ridley, D. Boyer, A.M. Wilson, K.L. Waddell, S.A. Pugh, and B.L. Conkling. 2014. The Forest Inventory and Analysis database: Database description and user guide version 6.0 for phase 2.
14. R Development Core Team. 2010. R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria.
15. Reineke, L.H. 1933. Perfecting a stand-density index for even-age forests. J. Agri. Res. 46:627- 638.
16. Turnblom, E. 2016. Stand density measures. Forest resources assessment: trees, stands, habitat & products. Available at
17. VanderSchaaf, C.L. 2013. Reineke’s stand density index: a quantitative and non-unitless measure of stand density. In: Proceedings of the 15th Biennial Southern Silvicultural Research Conference, Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. pp. 577–579.
18. West, P.W. 1982. Comparison of stand density measures in even-aged regrowth eucalypt forest of southern Tasmania. Can. J. For. Res. 13: 22-31.
19. Zeide, B. 2005. How to measure stand density. Trees. 19: 1-14.
20. Zeide, B. 2010. Comparison of self-thinning models: an exercise in reasoning. Trees. 24: 1117-1126.