Biomass conversion and expansion factors in Douglas-fir stands of different planting density: variation according to individual growth and prediction equations

Pasquale A. Marziliano, Giuliano Menguzzato, Angelo Scuderi, Clemente Scalise, Vittoria Coletta


Aim of study: We built biomass expansion factors (BCEFs) from Douglas-fir felled trees planted with different planting densities to evaluate the differences according tree size and planting density.

Area of study: The Douglas-fir plantation under study is located on the northern coastal chain of Calabria (Tyrrhenian side) south Italy.

Materials and methods: We derived tree level BCEFs, relative to crown (BCEFc), to stem (BCEFst = basic density, BD) and total above-ground (BCEFt) from destructive measurements carried out in a Douglas-fir plantation where four study plots were selected according to different planting densities (from 833 to 2500 trees per hectare). The measured BCEFs were regressed against diameter at breast height and total height, planting density, site productivity (SP) and their interactions to test the variation of BCEFs. Analysis of variance (ANOVA) and the post hoc Tukey comparison test were used to test differences in BCEFt, BCEFc and in BD between plots with different planting density.

Main results: BCEFs decreased with increasing total height and DBH, but large dispersion measures were obtained for any of the compartments in the analysis. An increasing trend with planting density was found for all the analyzed BCEFs, but together with planting density, BCEFs also resulted dependent upon site productivity. BCEFt average values ranged between 1.40 Mg m-3 in planting density with 833 trees/ha (PD833) to 2.09 Mg m-3 in planting density with 2500 trees/ha (PD2500), which are in the range of IPCC prescribed values for Douglas-fir trees.

Research highlights: Our results showed that the application of BCEF to estimate forest biomass in stands with different planting densities should explicitly account for the effect of planting density and site productivity.


biomass; biomass expansion factor; planting density; Pseudotsuga menziesii (Mirb.) Franco

Full Text:



António N, Tomé M, Tomé J, Soares P, Fontes L, 2007. Effect of tree, stand, and site variables on the allometry of Eucalyptus globulus tree biomass. Can J Forest Res 37: 895-906.

Black K, Tobin B, Siaz G, Byrne KA, Osborne B, 2004. Allometric regressions for an improved estimate of biomass expansion factors for Ireland based on a Sitka spruce chronosequence. Irish Forestry 61(1): 50–65.

Brown S, 2002. Measuring carbon in forests: current status and future challenges, Environ Pollut 116: 363–372.

Brown S, Gillespie AJR, Lugo AE, 1989. Biomass estimation methods for tropical forests with applications to forest inventory data. Forest Sciences 35(4): 381–902.

Brown SL, Schroeder PE, 1999. Spatial patterns of aboveground production and mortality of woody biomass for Eastern US forests. Ecological Application 9: 968-980.

Cantore V, Iovino F, 1989. Effetti dei diradamenti sull'umidità del suolo in popolamenti di douglasia della Catena Costiera (Calabria). Annali dell'Istituto Sperimentale per la Selvicoltura 20: 13-39.

Clutter JL, Fortson JC, Pienaar LV, Brister GH, Bailey RL, 1983. Timber Management: A Quantitative Approach. John Wiley & Sons, New York, USA.

Coletta V, Menguzzato G, Pellicone G, Veltri A, Marziliano PA, 2016. Effect of thinning on above-ground biomass accumulation in a Douglas-fir plantation in southern Italy. J. For. Res. (2016) 27(6):1313–1320.

Correia AC, Tomé M, Pacheco CA, Faias S, Dias AC, Freire J, Carvalho PO, Pereira JS, 2010. Biomass allometry and carbon factors for a Mediterranean pine (Pinus pinea L,) in Portugal. Forest Systems 19 (3): 418-433.

Curtis RO, 1967. Height–diameter and height–diameter–age equation for secondgrowth Douglas-fir. Forest Science 13 (4), 365–375.

Dutca I, Abrudan IV, Stancioiu PT, Blujdea V, 2010. Biomass conversion and expansion factors for young Norway spruce (Picea abies (L,) Karst,) trees planted on non-forest lands in Eastern Carpathians. Not Bot Hort Agrobot Cluj 38(3): 286–92.

Enes Duque T, Fonseca Fidalgo T, 2014. Biomass conversion and expansion factors are affected by thinning. Forest Systems 23(3): 438-447.

Food and Agriculture Organization of the United Nations, 1998. World Reference Base for Soil Resources, Rome: FAO, ISRIC, ISSS [Soil Resource Report n, 84].

Food and Agriculture Organization of the United Nations, 2000. Global Forest Resource Assessment, FAO Forestry Paper 140, FAO. Rome, 2001.

Fukuda M, Iehara T, Matsumoto M, 2003. Carbon stock estimates for sugi and hinoki forests in Japan. Forest Ecology and Management 184: 1–16.

Hägglund B, 1981. Evaluation of forest site productivity. Forestry Abstracts 42: 515–527.

Harrington TB, Harrington CA, DeBell DS, 2009. Effects of planting spacing and site quality on 25-year growth and mortality relationships of Douglas-fir (Pseudotsuga menziesii var, menziesii). Forest Ecology and Management 258: 18–25.

Ilomaki S, Nikinmaa E, Makela A, 2003. Crown rise due to competition drives biomass allocation in silver birch. Canadian Journal of Forest Research 33: 2395-2404.

IPCC, 2006. Intergovernmental Panel on Climate Change, Guidelines for National Greenhouse Gas Inventories [].

Kauppi P, Tomppo E, Ferm A, 1995. C and N storage in living trees within Finland since 1950s, Plant and soil 168-169: 633-638.

Kerr G, 2003. Effects of spacing on the early growth of planted Fraxinus excelcior L. Can J Forest Res, 33: 1196¬1207.

Landsberg JJ, Sands PJ, 2011. Physiological Ecology of Forest Production: Principles, Processes and Modelling. Oxford, UK: Elsevier Inc.

Lehtonen A, Mäkipää R, Heikkinen J, Sievänen R, Liski J, 2004. Biomass expansion factors (BEF) for Scots pine, Norway spruce and birch according to stand age for boreal forests. Forest Ecology and Management 188: 211–224.

Levy PE, Hale SE, Nicoli BC, 2010. Biomass expansion factors and root: shoot ratios for coniferous tree species in Great Britain. Forestry 77(5): 421-430.

Magalhães TM, Seifert T, 2015. Estimation of tree biomass, carbon stocks, and error propagation in mecrusse woodlands. Open Journal of Forestry 5: 471-488.

Marziliano PA, Lafortezza R, Colangelo G, Davies C, Sanesi G, 2013. Structural diversity and height growth models in urban forest plantations: a case-study in northern Italy. Urban Forestry & Urban Greening, 12(2):246–254.

Marziliano PA, Coletta V, Menguzzato G, Nicolaci A, Pellicone G, Veltri A, 2015a. Effects of planting density on the distribution of biomass in a Douglas-fir plantation in southern Italy. iForest 8: 368-376 [online 2014-09-09] URL:

Marziliano PA, Veltri A, Menguzzato G, Pellicone G, Coletta V, 2015b. A comparative study between "default method" and "stock change method" of Good Practice Guidance for Land Use, Land-Use Change and Forestry (IPCC, 2003) to evaluate carbon stock changes in forest. In: Atti del II Congresso Internazionale di Selvicoltura, Progettare il futuro per il settore forestale, Firenze, 26-29 novembre 2014, Accademia Italiana di Scienze Forestali, Firenze, Italy. Vol. 1, pp. 551-557.

Marziliano PA, Lafortezza R, Medicamento U, Lorusso L, Giannico V, Colangelo G, Sanesi G, 2015c. Estimating belowground biomass and root/shoot ratio of Phillyrea latifolia L. in the Mediterranean forest landscapes. Annals of Forest Science, 72:585–593.

Pajtík J, Konopka B, Lukac M, 2008. Biomass functions and expansion factors in young Norway spruce (Picea abies [L.] Karst.) trees. Forest Ecology and Management 256: 1096–1103.

Penman J, Gytarsky M, Hiraishi T, Krug T, Kruger D, Pipatti R, Buendia L, Miwa K, Ngara T, Tanabe K, and Wagner F, 2003. Definitions and Methodological Options to Inventory Emissions from Direct Human-induced Degradation of Forests and Devegetation of Other Vegetation Types. The Institute for Global Environmental Strategies for the IPCC and The Intergovernmental Panel on Climate Change, Hayama, Kanagawa, Japan.

Petersson H, Holm S, Ståhl G, Alger D, Fridman J, Lethonen A, Lundstrøm A, Mäkipää R, 2012. Individual tree biomass functions or biomass expansion factors for assessment of carbon stock changes in living biomass – A comparative study. Forest Ecology and Management 270: 78–84.

Pfister O, Wallentin C, Nilsson U, Ekö PM, 2007. Effects of wide spacing and thinning strategies on wood quality in Norway spruce (Picea abies) stands in southern Sweden. Scand J For Res 22:333– 343.

R Development Core Team, 2008. R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria.

Sanquetta CR, Dalla Corte AP, Silva FS, 2011. Biomass expansion factor and root-to-shoot ratio for Pinus in Brazil. Carbon Balance and Management 6(6): 1–8.

Schoene D, 2002. Terminology in assessing and reporting forest carbon change. In: Second expert meeting on harmonizing forest-related definitions for use by various stakeholders, FAO, Rome.

Soares P, Tome M, 2012. Biomass expansion factors for Eucalyptus globules stands in Portugal. Forest systems 21(1): 141-152.

Somogyi Z, Cienciala E, Mäkipää R, Muukkonen P, Lehtonen A, Weiss P, 2006. Indirect methods of large-scale forest biomass estimation. European Journal of Forest Research 126 (2): 197-207.

Teobaldelli M, Somogyi Z, Migliavacca M, Usoltsev VA, 2009. Generalized functions of biomass expansion factors for conifers and broadleaved by stand age, growing stock and site index. Forest Ecology and Management 257(3): 1004–1013.

Tobin B, Nieuwenhuis M, 2007. Biomass expansion factors for Sitka spruce (Picea sitchensis (Bong) Carr,) in Ireland. European Journal of Forest Research 126: 189-196.

UN-ECE/FAO, 2000. Forest Resources of Europe, CIS, North America, Australia, Japan and New Zealand (industrialized temperate/boreal countries). UNECE/ FAO Contribution to the Global Forest Resources Assessment 2000 Main Report United Nations, New York, Geneva.

United Nations Framework Convention on Climate Change – UNFCCC, 1997. Kyoto Protocol to the United Nations Framework Convention on Climate Change. FCCC/CP/L7/Add.1, 10 December 1997, UN. New York, USA.

Viken KO, 2012. Biomass equations and biomass expansion factors (BEFs) for pine (Pinus spp.), spruce (Picea spp.) and broadleaved dominated stands in Norway. Mastergradsoppgave ved Institutt for naturforvaltning, Universitetet for milijø- og biovitenskap 43 s. + vedlegg.

Zianis D, Muukkonen P, Ma¨kipa¨a¨ R, Mencuccini M. 2005. Biomass and stem volume equations for tree species in Europe. Silva Fennica Monographs N. 4, pp. 1–2, 5–63

Zuur AF, Ieno EN, Elphick CS, 2010. A protocol for data exploration to avoid common statistical problems. Methods in Ecology and Evolution 1: 3–14.

DOI: 10.5424/fs/2017261-10239