Variation in growth potential between hybrid clones of Eucalyptus trees in eastern South Africa

Abstract

Growth of commercial forestry is highly dependent on the availability of fast-growing planting materials. Consequently, the efficient utilization of fast-growing plantations can greatly impact productivity. The objectives of this study were to evaluate variations in the growth potential of two clones and to estimate the average stem radial growth advantage of a fast-growing clone using data obtained from Sappi landholdings in eastern South Africa and a mixed modelling approach that permits the incorporation of covariance structure into the statistical model. During the first 2 years of growth, the stem radius of nine trees each of two clones was measured using dendrometer attached to the tree. A second-degree fractional polynomial model was chosen to show the functional relationship between stem radius and tree age. Growth of the two hybrid clones differed significantly. The Eucalyptus grandis × Eucalyptus urophylla clone grew faster than the E. grandis × camaldulensis clone, indicating better genetic potential for rapid growth and yield. This study can be considered as starting point to further compare the potential for rapid growth of several hybrid clones using the longitudinal data modelling approach.

Keywords

Covariance function / Dendrometer trial / Growth rate / Loess / Longitudinal study / Random slope

References

[1] Arya ID, Sharma S, Arya S. Micro propagation of superior eucalyptus hybrids FRI-5 (Eucalyptus camaldulensis Dehn × E.tereticornis Sm) and FRI-14 (Eucalyptus torelliana FV Muell × E.citriodora Hook): a commercial multiplication and field evaluation. Afr J Biotechnol, 2009, 8: 5718-5726.

[2] Borges SR, Xavier A, de Oliveira LS, Lopes AP, Otonis WC. In vitro multiplication of hybrid clones of Eucalyptus globulus. Rev Arvore, 2011, 35: 173-182. in Portuguese with an English abstract)

[3] Butcher PA, Ak Skinner, Gardiner CA. Increased inbreeding and inter –species gene flow in remnant populations of the rare Eucalyptus benthamii. Conser Genet, 2005, 6: 213-226.

[4] Chazdon RL, Finegan B, Capers RS, Salgado-Negret B, Casanoves F, Boukili V, Norden N. Composition and dynamics of functional groups of trees during tropical forest succession in northeastern Costa Rica. Biotropica, 2010, 42: 31-40.

[5] CIFOR. Investing in the future: the private sector and sustainable forest management. A case study of progress towards sustainable forest management in the South African plantation forest industry, 2000, Bogor: Center for international Forest Research.

[6] Cleveland WS, Devlin SG. Locally weighted regression: an approach to regression analysis by local fitting. J Am Stat Assoc, 1988, 83(403): 596-610.

[7] Cleveland WS, Grosse E, Shyu WM. Local regression models. Stat Models S, 1992, 2: 309-376.

[8] Darrow WK (1996) Species trials of cold-tolerant eucalypts in summer rainfall zone of South Africa: results at six year of age. Institute for Commercial Research Bulletin Series 9/96, Pietermaritzburg, South Africa

[9] Diggle PJ, Liang KY, Zeger SL. Analysis of longitudinal data, 1994, Oxford: Oxford University Press.

[10] Drew DM (2004) EFR092T dendrometer trial phases one technical report. Division of Water, Environment and Forestry Technology, CSIRO

[11] Drew D, Downes G, Grzeskowiak V, Naidoo T. Differences in daily stem size variation and growth in two hybrid eucalypt clones. Trees Struct Funct, 2009, 23: 585-595.

[12] FAO (2001) Global forest resources assessment 2000: main report. FAO Forestry Paper 140. FAO, Rome, Italy

[13] Finegan BM, Camacho M, Zamora N. Diameter increment patterns among 106 tree species in a logged and silviculturally treated Costa Rican rain forest. For Ecol Manag, 1999, 121(3): 159-176.

[14] Fitzmaurice GM, Laird NM, Ware JH. Applied longitudinal analysis, 2004, New York: Wiley.

[15] Galloway G (2003) Comparison of the performance of various sources of E. grandis and operational clones under operational conditions. Sappi Forests Research File Note ESST002aK

[16] Herault BJ, Ouallet J, Blanc L, Wagner F, Baraloto C. Growth responses of neotropical trees to logging gaps. J Appl Ecol, 2010, 47: 821-831.

[17] Herbert MA. Own DL. Site requirements and species matching: Eucalypts and Wattles. South African forestry handbook, 2000, Pretoria: South African institute of Forestry 85 94

[18] James GM, Wang J, Zhu J. Functional linear regression that’s interpretable. Ann Stat, 2009, 37(5A): 2083-2108.

[19] Long JD, Ryoo J. Using fractional polynomials to model non-linear trends in longitudinal data. Br J Math Stat Psychol, 2010, 63(1): 177-203.

[20] Malan FS (1995) Eucalyptus improvement for lumber production. In: IPEF, IPT, IUFRO, ESALQ (eds) Anais do Seminário Internacional de Utilização da Madeira de Eucalipto para Serraria, Sao Paulo, pp 1–19

[21] Melesse SF, Zewotir T. The effect correlated climatic factors on the radial growth of eucalypt trees grown in coastal Zululand of South Africa. Afr J Agric Res, 2013, 8(14): 1233-1244.

[22] Melesse SF, Zewotir T. Fitting three parameter growth curves using a nonlinear mixed effects modelling approach. S Afr Stat J, 2015, 49(2): 223-240.

[23] Meng SX, Huang SH. Incorporating correlated error structures into mixed forest growth models: prediction and inference implications. Can J For Res, 2010, 40(5): 977-990.

[24] Nourissier S, Monteuuis O. In vitro rooting of two Eucalyptus urophylla × Eucalyptus grandis mature clones. In Vitro Cell Dev Biol Plant, 2008, 44: 263-272.

[25] Owen DL. South African forestry handbook, 2000 4 Pretoria: Southern African Institute of Forestry.

[26] Pallett RN, Sale G. The relative contributions of tree improvement and cultural practice toward productivity gains in Eucalyptus pulpwood stands. For Ecol Manag, 2004, 193: 33-44.

[27] Pinheiro JC, Bates DM. Mixed effects models in S and S-Plus, 2000, New York: Springer

[28] Royston P, Altman DG. Regression using fractional polynomials of continuous covariates: parsimonious parametric modeling (with discussion). J R Stat Soc Ser C (Appl Stat), 1994, 43: 429-467.

[29] Royston P, Ambler G, Sauerbrei W. The use of fractional polynomials to model continuous risk variables in epidemiology. Int J Epidemiol, 1999, 28(5): 964-974.

[30] Schönau APG, Gardner RAW (1991) Eucalyptus colder areas in South Africa. In: Schönau APG (ed) Intensive forestry: the role of eucalypts. IUFRO working group p2.02-01, Durban, pp 467–479

[31] Shaw MJP (1994) Sappi Forests research for improved pulp yield and quality. In: Proceedings of the symposium on the management of forest research: emerging trends. IUFRO subject group S 6, pp 89–93

[32] Stanger TK, Galloway GM, Rectif ECL. Final results from a trial to test the effect of plot size on Eucalyptus hybrid clone ranking in coastal Zululand, South Africa. South For J For Sci, 2011, 73: 131-135.

[33] Turnbull JW. Eucalypt plantations. New For, 1999, 17: 17-52.

[34] Van WYK G (1987) Hybrid eucalypts for improvement of yields on marginal forest sites. Paper presented at the 11th regular meeting of the standing committee for forestry of the southern African regional commission for the conservation and utilization of the soil (SARCCUS), Maseru, Lesotho

[35] Van WYK G, Schönau APG, Schön PP (1988) Growth potential and adaptability of young hybrids. IUFRO meeting Breeding tropical trees—population structure and genetic improvement strategies in clonal and seedling forestry. Pattaya, Thailand, 28 Nov–3 Dec 1988

[36] Verbeke G, Molenberghs G (1997) Linear mixed models in practice: a SAS oriented approach. Lecture notes in statistics, vol 126. Springer, New York

[37] Verbeke G, Molenberghs G. Linear mixed models for longitudinal data, 2000, New York: Springer.

[38] Watt MP. Genotypic—unspecific protocols for the commercial micropropagation of Eucalyptus grandis × nitens and E. grandis × urophylla. Turk J Agric For, 2014, 38: 125-133.

[39] Watt MS, Kimberley MO, Richardson B, Whitehead D, Mason EG. Testing a juvenile tree growth model sensitive to competition from weeds, using Pinus radiata at two contrasting sites in New Zealand. Can J For Res, 2004, 34(10): 1985-1992.

[40] Yang G, Cao WQ, Liu DX, Kang MZ, Letort V, Xing MJ, Huang XY. Growth and development simulation based on functional-structural model Green Lab for poplar. Afr J Agric Res, 2011, 6(13): 3071-3077.