Abstract
Plantation forest species were introduced into South Africa due to limited availability of native forests for wood-derived products. Currently, the Mexican pine species, Pinus patula, is the most widely planted softwood species in the country. To study the effect of growth environment on wood and processing properties for the species, sample plots were established in a 20-year rotation covering a wide range of soil geologies and altitudes in Mpumalanga, South Africa. Temperature and seasonal rainfall were also determined for the sample plots. Randomly selected sample trees were harvested from the plots and processed at a plywood plant to determine veneer recovery and quality. Trees grown on sites composed of granite soils, with higher annual maximum temperatures and less rainfall, found in the Highveld region, displayed superior tree size, slenderness, and volume growth, compared to trees grown on dolomite and shale soils common to the Lowveld region. Veneer derived from Lowveld trees had more splits which were largely related to defects. Larger trees also had a greater percentage volumetric heartwood and a smaller live crown, compared to smaller trees. Highveld trees had greater net veneer recovery and produced better quality veneer than trees grown on the Lowveld. In the Mpumalanga forestry region, strong co-relatedness exists between soil geology, altitude, and climate. Although tree form and wood properties were found to differ with varying soil geology and altitude, these differences were primarily related to climate rather than soil properties. These findings highlight the pitfalls associated with neglecting either climate or soil properties when analysing site-specific growing conditions on tree growth and form.
Funding source: York Timbers
Acknowledgements
We would like to thank all of the York Timbers staff who assisted in the forests and at the Sabie processing facilities, to ensure the samples were collected, processed, and analysed. We would also like to thank the late Chief Executive Officer of York Timbers, Mr. Piet van Zyl for allocating funding to this project and believing in the power of science. This publication is dedicated to him.
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Author contributions: Jaco-Pierre Van der Merwe collected the data, completed the modelling, and wrote the manuscript. Charlie Clarke and Shawn Mansfield aided with project conceptualisation, and reviewed and edited the manuscript. Sechaba Madiope assisted in processing and measurement of disc core samples. Hilton Kuisis and Olwethu Spogter supervised the debarking of sample logs, including automated log form measurements, and log batching. Oscar Tait and Jaco Potgieter supervised the peeling of veneer logs, drying, and grading of veneer sheets.
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Research funding: Funding for this project was provided by York Timbers, South Africa, as well as sampling and the allocation of company resources.
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Conflict of interest statement: The authors declare that they have no conflicts of interest regarding this article.
References
Adlard, P.G. (1969). Quantitative effects of pruning Pinus patula in Malawi. Common For. Rev. 48: 339–349.Search in Google Scholar
Albaugh, T.J., Maier, C.A., Campoe, O.C., Yáñez, M.A., Carbaugh, E.D., Carter, D.R., Cook, R.L., Rubilar, R.A., and Fox, T.R. (2020). Crown architecture, crown leaf area distribution, and individual tree growth efficiency vary across site, genetic entry, and planting density. Trees 34: 73–88, https://doi.org/10.1007/s00468-019-01898-3.Search in Google Scholar
Aye, T.N., Brännström, Å., and Carlsson, L. (2022). Prediction of tree sapwood and heartwood profiles using pipe model and branch thinning theory. Tree Physiol 42: 2174–2185, https://doi.org/10.1093/treephys/tpac065.Search in Google Scholar PubMed PubMed Central
Barbosa, L.O., Finger, C.A.G., Costa, E.A., Campoe, O.C., and Schons, C.T. (2021). Using crown characterisation variables as indicators of the vigour, competition and growth of Brazilian pine. South. For. 83: 240–253, https://doi.org/10.2989/20702620.2021.1978825.Search in Google Scholar
Baltrušaitis, A. and Pranckevičienė, V. (2001). The influence of log offset on sawn timber volume yield. Mater. Sci. 11: 403–406.Search in Google Scholar
Bárcenas-Pazos, G., Velázquez-Morales, P., and Dávalos-Sotelo, R. (2000). Effect of lignin content on shrinkage of four Mexican woods. Holzforschung 54: 541–543, https://doi.org/10.1515/hf.2000.091.Search in Google Scholar
Bergström, B. (2003). Chemical and structural changes during heartwood formation in Pinus sylvestris. Forestry 76: 45–53, https://doi.org/10.1093/forestry/76.1.45.Search in Google Scholar
Brischke, C. and Alfredsen, G. (2022). Biological durability of pine wood. Wood. Mater. Sci. Eng. 1: 1748–0272, https://doi.org/10.1080/17480272.2022.2104134.Search in Google Scholar
Brown, G.S. (1962). The importance of stand density in pruning prescriptions. Empire For. Rev. 41: 246–257.Search in Google Scholar
Cardoso, D.J. and Arce, J.E. (2010). Usage of the pruned log index for loblolly pine (Pinus taeda) and slash pine (Pinus elliottii). Br. J. For. Res. 30: 119–128, https://doi.org/10.4336/2010.pfb.30.62.119.Search in Google Scholar
Chakraborty, D., Jandl, R., Kapeller, S. and Schueler, S. (2019). Disentangling the role of climate and soil on tree growth and its interaction with seed origin. Sci. Total Environ. 654: 393–401, https://doi.org/10.1016/j.scitotenv.2018.11.093.Search in Google Scholar PubMed
Chan, J.M., Raymond, C.A. and Walker, J.C.F. (2013). Development of heartwood in response to water stress for radiata pine in Southern New South Wales, Australia. Trees 27: 607–617, https://doi.org/10.1007/s00468-012-0815-3.Search in Google Scholar
Chang, W.S. and Wang, A.S.D. (1990). Effects of a 90° ply on matrix cracks and edge delamination in composite laminates. Compos. Sci. Technol. 38: 143–157, https://doi.org/10.1016/0266-3538(90)90003-n.Search in Google Scholar
Charlton, R.A., Naghizadeh, Z., Kunneke, A., and Wessels, C.B. (2020). The effect of planting density on the stem form of Pinus patula trees. South. For. 82: 70–74, https://doi.org/10.2989/20702620.2020.1733753.Search in Google Scholar
Crous, J.W., Morris, A.R., and Scholes, M.C. (2008). Growth and foliar nutrient response to recent applications of phosphorus (P) and potassium (K) and to residual P and K fertiliser applied to the previous rotation of Pinus patula at Usutu. Swaziland. For. Ecol. Manage. 256: 712–721, https://doi.org/10.1016/j.foreco.2008.05.024.Search in Google Scholar
Da Ros, L., Thomas, B.R., and Mansfield, S.D. (2021). Wood quality trait associations with climate: room for improvement in two northern commercial tree species? For. Ecol. Manage. 497: 119492, https://doi.org/10.1016/j.foreco.2021.119492.Search in Google Scholar
Dickson, R., Joe, B., Johnstone, D., Austin, S., and Ribton-Turner, F. (2005). Pre-processing prediction of wood quality in peeler logs grown in northern New South Wales. Aust. For. 68: 186–191, https://doi.org/10.1080/00049158.2005.10674964.Search in Google Scholar
Dobner, M., Nutto, L. and Higa, A.R. (2013). Recovery rate and quality of rotary peeled veneer from 30-year-old Pinus taeda L. logs. Ann. For. Sci. 70: 429–437, https://doi.org/10.1007/s13595-013-0274-z.Search in Google Scholar
Downes, G.M., Harrington, J.J., Drew, D.M., Lausberg, M., Muyambo, P., Watt, D., and Lee, D.J. (2022). A comparison of radial wood property variation on Pinus radiata between an IML PD-400 ‘Resi’ instrument and increment cores analysed by SilviScan. Forests 13: 751, https://doi.org/10.3390/f13050751.Search in Google Scholar
Dudík, R., Borůvka, V., Ziedler, A., Holeček, T., and Riedl, M. (2020). Influence of site conditions and quality of birch wood on its properties and utilization after heat treatment. Part II: surface properties and marketing evaluation of the effect of the treatment on final usage of such wood. Forests 11: 556, https://doi.org/10.3390/f11050556.Search in Google Scholar
Erasmus, J., Kunneke, A., Drew, D.M., and Wessels, C.B. (2018). The effect of planting spacing on Pinus patula stem straightness, microfibril angle and wood density. Forestry 91: 247–258, https://doi.org/10.1093/forestry/cpy005.Search in Google Scholar
Forestry Economics Services CC (FES) (2020). Report on commercial timber resources and primary roundwood processing in South Africa. Department of Agriculture, Forestry and Fisheries, Pretoria.Search in Google Scholar
Gentvilas, V., Downes, G.M., Neyland, M., Hunt, M., Jacobs, A., and O’Reilly-Wapstra, J. (2021). Friction correction when predicting wood basic density using drilling resistance. Holzforschung 75: 508–516, https://doi.org/10.1515/hf-2020-0156.Search in Google Scholar
Gerchow, M., Marshall, J.D., Kühnhammer, K., Dubbert, M., and Beyer, M. (2022). Thermal imaging of increment cores: a new method to estimate sapwood depth in trees. Trees 37: 1–11, https://doi.org/10.1007/s00468-022-02352-7.Search in Google Scholar
Gjerdrum, P. (2003). Heartwood in relation to age and growth rate in Pinus sylvestris L. in Scandinavia. Forestry 76: 413–424, https://doi.org/10.1093/forestry/76.4.413.Search in Google Scholar
Gonzalez-Benecke, C.A. and Martin, T.A. (2010). Water availability and genetic effects on water relations of loblolly pine (Pinus taeda) stands. Tree Physiol 30: 376–392, https://doi.org/10.1093/treephys/tpp118.Search in Google Scholar PubMed
Gorges, J., Huber, M., Sauter, U.H., and Dormann, C.F. (2021). Curvature of logs – development of and comparison between different calculation approaches. Forests 12: 857, https://doi.org/10.3390/f12070857.Search in Google Scholar
Grekin, M. and Verkasalo, E. (2010). Variations in basic density, shrinkage and shrinkage anisotropy of Scots pine wood from mature mineral soil stands in Finland and Sweden. Balt. For. 16: 113–125.Search in Google Scholar
Guo, F. and Altaner, C.M. (2018). Properties of rotary peeled veneer and laminated veneer lumber (LVL) from New Zealand grow Eucalyptus globoidea. N.Z. J. For. Sci. 48: 3, https://doi.org/10.1186/s40490-018-0109-7.Search in Google Scholar
Hamilton, M.G., Blackburn, D.P., McGavin, R.L., Bailléres, H., Vega, M., and Potts, B.M. (2015). Factors affecting log traits and green rotary-peeled veneer recovery from temperate eucalypt plantations. Ann. For. Sci. 72: 357–365, https://doi.org/10.1007/s13595-014-0430-0.Search in Google Scholar
Hazenberg, G. and Yang, K.C. (1991). The relationship of tree age with sapwood and heartwood. Width in black spruce, Picea mariana (Mill) B.S.P. Holzforschung 45: 317–320, https://doi.org/10.1515/hfsg.1991.45.5.317.Search in Google Scholar
Hu, G., Liu, H., Shangguan, H., Wu, X., Xu, X., and Williams, M. (2018). The role of heartwood water storage for semi-arid trees under drought. Agric. For. Meteorol: 534–541, https://doi.org/10.1016/j.agrformet.2018.04.007.Search in Google Scholar
Isik, F. and Li, B. (2011). Rapid assessment of wood density of live trees using the Resistograph for selection in tree improvement programs. Can. J. For. Res. 33: 2426–2435, https://doi.org/10.1139/x03-176.Search in Google Scholar
Kanzler, A., Payn, K., and Nel, A. (2012). Performance of two Pinus patula hybrids in southern Africa. South. For. 74: 19–25, https://doi.org/10.2989/20702620.2012.683639.Search in Google Scholar
Kassambara, A. (2022). ggcorrplot: visualization of a correlation matrix using ’ggplot2’. R package version 0.1.4, https://CRAN.R-project.org/package=ggcorrplot.Search in Google Scholar
Kotze, H. (1995). Merchantable volume and taper equations for Pinus patula, M. Sc. thesis. Stellenbosch University.Search in Google Scholar
Krause, C. and Plourde, P.-Y. (2008). Stem deformation in young plantations of black spruce (Picea mariana (Mill.) B.S.P.) and jack pine (Pinus banksiana Lamb.) in the boreal forest of Quebec. Canada. For. Ecol. Manage. 225: 2213–2224, https://doi.org/10.1016/j.foreco.2007.12.046.Search in Google Scholar
Kretschmann, D.E. (2010). Mechanical properties of wood. In: Ross, R.J. (Ed.), Wood handbook: wood as an engineering material. General Technical Report FPL-GTR-190. Department of Agriculture, Forest Service, Forest Products Laboratory, Madison, Wisconsin, United States of America.Search in Google Scholar
Kunickaya, O.A., Pomiguev, A., Kruchinin, I.N., Storodubtseva, T., Voronova, A.M., Levushkin, D., Borisov, V., and Ivanov, V. (2022). Analysis of modern wood processing techniques in timber terminals. Cent. Eur. For. J. 68: 51–59, https://doi.org/10.2478/forj-2021-0017.Search in Google Scholar
Kutscha, N.P. and Sachs, I.B. (1962). Color tests for differentiating heartwood and sapwood in certain softwood species. Report 2246, United States Department of Agriculture.Search in Google Scholar
Laskowska, A., Kozakiewicz, P., Zbieć, M., Zatoń, P., Oleńska, S., and Beer, P. (2018). Surface characteristics of Scots pine veneers produced with a peeling process in industrial conditions. BioResources 13: 8342–8357, https://doi.org/10.15376/biores.13.4.8342-8357.Search in Google Scholar
Lavalette, A., Cointe, A., Pommier, R., Danis, M., Delisée, C., and Legrand, G. (2016). Experimental design to determine the manufacturing parameters of a green-glued plywood panel. Eur. J. Wood Prod. 74: 543–551, https://doi.org/10.1007/s00107-016-1015-4.Search in Google Scholar
Lenth, R.V. (2016). Least-squares means: the R package lsmeans. J. Stat. Softw. 69: 1–33, https://doi.org/10.18637/jss.v069.i01.Search in Google Scholar
Lenth, R. (2020). Emmeans: estimated marginal means, aka least-squares means. R package version 1.5.0, https://CRAN.R-project.org/package=emmeans.Search in Google Scholar
Louw, J.H. (2016). The value of six key soil variables for incorporation into a South African forest site classification system. South. For. 78: 81–95, https://doi.org/10.2989/20702620.2016.1157982.Search in Google Scholar
Louw, J.H. and Scholes, M.C. (2006). Site index functions using site descriptors for Pinus patula plantations in South Africa. For. Ecol. Manage. 225: 94–103, https://doi.org/10.1016/j.foreco.2005.12.048.Search in Google Scholar
Lowell, E.C., Maguire, D.A., Briggs, D.G., Turnblom, E.C., Jayawickrama, K.J.S., and Bryce, J. (2014). Effects of silviculture and genetics on branch/knot attributes of coastal Pacific Northwest Douglas-Fir and implications for wood quality – a synthesis. Forests 5: 1717–1736, https://doi.org/10.3390/f5071717.Search in Google Scholar
Lutz, J.F. (1971). Wood and log characteristics affecting veneer production. Report AD0719618, Forest Service research paper. Forest Products Lab, Madison, Wisconsin.Search in Google Scholar
Lynch, T.B. and Clutter, M.L. (1998). A system of equations for prediction of plywood veneer total yield and yield by grade for loblolly pine plywood bolts. For. Prod. J. 48: 80–88.Search in Google Scholar
Malan, F.S. (2003). The wood quality of the South African timber resource for high-value solid wood products and its role in sustainable forestry. South. Afr. For. J. 198: 53–62, https://doi.org/10.1080/20702620.2003.10431735.Search in Google Scholar
Mansfield, S.D., Parish, R., Goudie, J.W., Kang, K.-Y., and Ott, P. (2007). The effects of crown ratio on the transition from juvenile to mature wood production in lodgepole pine in western Canada. Can. J. For. Res. 37: 1450–1459, https://doi.org/10.1139/x06-299.Search in Google Scholar
Mansfield, S.D., Parish, R., Ott, P.K., Hart, J.F., and Goudie, J.W. (2016). Assessing the wood quality of interior spruce (Picea glauca × P. engelmannii): variation in strength, relative density, microfibril angle, and fiber length. Holzforschung 70: 223–234, https://doi.org/10.1515/hf-2015-0008.Search in Google Scholar
McGavin, R.L. and Leggate, W. (2019). Comparison of processing methods for small-diameter logs: sawing versus rotary peeling. Bioresources 14: 1545–1563, https://doi.org/10.15376/biores.14.1.1545-1563.Search in Google Scholar
McGavin, R.L., McGrath, J., Fitzgerald, C., Kumar, C., Oliver, C., and Lindsay, A. (2021). Sawn timber and rotary veneer processing and grade recovery investigation of northern Australian plantation grown African mahogany. Bioresources 16: 1891–1913, https://doi.org/10.15376/biores.16.1.1891-1913.Search in Google Scholar
McIntire, C.D., Cunliffe, A.M., Boschetti, F., and Litvak, M.E. (2022). Allometric relationships for predicting aboveground biomass, sapwood, and leaf area of two-needle Piñon pine (Pinus edulis) amid open-grown conditions in central New Mexico. For. Sci. 68: 152–161, https://doi.org/10.1093/forsci/fxac001.Search in Google Scholar
Moreno Chan, J., Raymond, C.A., and Walker, J.C.F. (2013). Development of heartwood in response to water stress for radiata pine in Southern New South Wales, Australia. Trees 27: 607–617, https://doi.org/10.1007/s00468-012-0815-3.Search in Google Scholar
Muller, B.G., Louw, J.H., and Malan, F.S. (2017). Variation in selected solid wood properties of young Pinus patula from diverse sites in the Mpumalanga escarpment area in South Africa. South. For. 79: 317–327, https://doi.org/10.2989/00306525.2016.1255376.Search in Google Scholar
Munalula, F., Blumentritt, M., Seifert, T. and Wessels, C.B. (2016). A method for determining knotty core sizes of standing Pinus patula trees based on tree ring sampling. Dendrochronologia 38: 11–17, https://doi.org/10.1016/j.dendro.2016.02.003.Search in Google Scholar
Nava-Nava, A., Santiago-García, W., Quinonez-Barraza, G., De los Santos-Posadas, H.M., Valdez-Lazalde, J.R., and Ángeles-Pérez. (2022). Climatic and topographic variables improve estimation accuracy of Patula pine forest site productivity in Southern Mexico. Forests 13: 1277, https://doi.org/10.3390/f13081277.Search in Google Scholar
Ondrejka, V., Gergel, T., Bucha, T., and Pastor, M. (2021). Innovative methods of non-destructive evaluation of log quality. Cent. Eur. For. J. 67: 3–13, https://doi.org/10.2478/forj-2020-0021.Search in Google Scholar
Panshin, A.J., de Zeeuw, C., and Brown, H.P. (1964). Chapter 7. In: Textbook of wood technology. McGraw-Hill, New York, pp. 240–285.Search in Google Scholar
Partridge, T.C., Dollar, E.S.J., Moolman, J., and Dollar, L.H. (2010). The geomorphic provinces of South Africa, Lesotho and Swaziland: a physiographic subdivision for earth and environmental scientists. Trans. R. Soc. S. A. 65: 1–47, https://doi.org/10.1080/00359191003652033.Search in Google Scholar
Peng, M., Chui, Y.H., Ho, Y.-C., Wang, W.-C. and Zhou, Y. (2011). Investigation of shrinkage in softwood using digital image correlation method. Appl. Mech. Mater. 83: 157–161, https://doi.org/10.4028/www.scientific.net/amm.83.157.Search in Google Scholar
Peng, M., Kershaw, J.A., Chui, Y.H., and Gong, M. (2013). Modelling of tangential, radial, and longitudinal shrinkage after drying in jack pine and white spruce. Can. J. For. Res. 43: 742–749, https://doi.org/10.1139/cjfr-2013-0127.Search in Google Scholar
Petit, G., Anfodillo, T., Carraro, V., Grani, F., and Carrer, M. (2010). Hydraulic constraints limit height growth in trees at high altitude. New Phytol. 189: 241–252, https://doi.org/10.1111/j.1469-8137.2010.03455.x.Search in Google Scholar PubMed
Pinto, I., Pereira, H., and Usenius, A. (2004). Heartwood and sapwood development within maritime pine (Pinus pinaster Ait.) stems. Trees 18: 284–294, https://doi.org/10.1007/s00468-003-0305-8.Search in Google Scholar
Pompa-García, M., Hevia, A., and Camarero, J.J. (2021). Minimum and maximum wood density as proxies of water availability in two Mexican pine species coexisting in a seasonally dry area. Trees 35: 597–607, https://doi.org/10.1007/s00468-020-02062-y.Search in Google Scholar
Pothier, D., Margolis, H.A., Poliquin, J., and Waring, R.H. (2011). Relation between the permeability and the anatomy of jack pine sapwood with stand development. Can. J. For. Res. 19: 1564–1570, https://doi.org/10.1139/x89-238.Search in Google Scholar
Poulsen, Z.C. and Hoffman, M.T. (2015). Changes in the distribution of indigenous forest in table mountain national park during the 20th century. S. Afr. J. Bot. 101: 49–56, https://doi.org/10.1016/j.sajb.2015.05.002.Search in Google Scholar
Prka, M., Zečić, Ž., Krpan, A.P.B., and Vusić, D. (2009). Characteristics and share of European beech false heartwood in felling sites of central Croatia. Croat. J. For. Eng. 30: 37–49.Search in Google Scholar
Raut, S., Dahlen, J., Bullock, B., Montes, C., and Dickens, D. (2022). Models to predict whole-disk specific gravity and moisture content in planted longleaf pine from cutover and old field sites. Can. J. For. Res. 52: 137–147, https://doi.org/10.1139/cjfr-2021-0092.Search in Google Scholar
R Core Team (2022). R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria, URL https://www.R-project.org/.Search in Google Scholar
Ryan, M.G. (2010). Temperature and tree growth. Tree Physiol. 30: 667–668, https://doi.org/10.1093/treephys/tpq033.Search in Google Scholar PubMed
Şahin, A. and Çomak, A. (2022). Suitability of various volume equations for logs volume calculation. Forestist 73: 138–144, https://doi.org/10.5152/forestist.2022.22033.Search in Google Scholar
Santiago-García, W., Pérez-López, E., Quiñonez-Barraza, G., Rodríguez-Ortiz, G., Santiago-García, E., Ruiz-Aquino, F., and Tamarit-Urias, J.C. (2017). A dynamic system of growth and yield equations for Pinus patula. Forests 8: 465, https://doi.org/10.3390/f8120465.Search in Google Scholar
Santos, L.M.H., de Almeida, M.N.F., da Silva, J.G.M., Vidaurre, G.B., Hein, P.R.G., da Silva, G.F., Zanuncio, A.J.V., Filho, C.V.F., Campinhos, E.N., Mafia, R.G., et al.. (2021). Variations in heartwood formation and wood density as a function of age and plant spacing in a fast-growing eucalyptus plantation. Holzforschung 75: 979–988, https://doi.org/10.1515/hf-2020-0215.Search in Google Scholar
Savva, Y., Koubaa, A., Tremblay, F., and Bergeron, Y. (2010). Effects of radial growth, tree age, climate, and seed origin on wood density of diverse jack pine populations. Trees 24: 53–65, https://doi.org/10.1007/s00468-009-0378-0.Search in Google Scholar
Schimleck, L., Dahlen, J., Apiolaza, L.A., Downes, G., Emms, G., Evans, R., Moore, J., Pâques, L., Van den Bulcke, J., and Wang, X. (2019). Non-destructive evaluation techniques and what they tell us about wood property variation. Forests 10: 728, https://doi.org/10.3390/f10090728.Search in Google Scholar
Schulgasser, K. and Witztum, A. (2015). How the relationship between density and shrinkage of wood depends on its microstructure. Wood Sci. Technol. 49: 389–401, https://doi.org/10.1007/s00226-015-0699-7.Search in Google Scholar
Schutz, C.J., Christie, S.I., and Herman, B. (1991). Site Relationships for some wood properties of pine species in plantation forests of Southern Africa. South. Afr. For. J. 156: 1–6, https://doi.org/10.1080/00382167.1991.9629080.Search in Google Scholar
Shupe, T.F., Hse, C.Y., Grozdits, G.A., and Choong, E.T. (1997). Effects of silvicultural practice and veneer layup on some mechanical properties of loblolly pine plywood. For. Prod. J. 47: 101–106.Search in Google Scholar
Słupianek, A., Dolzblasz, A., and Sokołowska, K. (2021). Xylem parenchyma – role and relevance in wood functioning in trees. Plants 10: 1247, https://doi.org/10.3390/plants10061247.Search in Google Scholar PubMed PubMed Central
South African National Standards (SANS) (2008). Plywood and composite board. SANS 929: 2008.Search in Google Scholar
Syafii and Novari, F. (2021). Study of veneer yield and amount of waste in veneer stripping with spindle-less type rotary Lathe machine. Buletin Poltanesa 22: 95–100.10.51967/tanesa.v22i1.334Search in Google Scholar
Tang, Y. and Li, W. (2019). lfda: local Fisher discriminant analysis in R. J. Open Source Softw. 4: 1572, https://doi.org/10.21105/joss.01572.Search in Google Scholar
Tang, Y., Horikoshi, M., and Li, W. (2016). ggfortify: unified interface to visualize statistical result of popular R packages. R J. 8: 478–489.10.32614/RJ-2016-060Search in Google Scholar
Tarelkina, T.V., Galibina, N.A., Moshnikov, S.A., Nikerova, K.M., Moshkina, E.V., and Genikova, N.V. (2022). Anatomical and morphological features of Scots pine heartwood formation in two forest types in the Middle Taiga Subzone. Forests 13: 91, https://doi.org/10.3390/f13010091.Search in Google Scholar
Tintner, J. and Smidt, E. (2018). Resistance of wood from black pine (Pinus nigra var. austriaca) against weathering. J. Wood Sci. 64: 816–822, https://doi.org/10.1007/s10086-018-1753-5.Search in Google Scholar
Toledo, M., Poorter, L., Pẽna-Claros, M., Alarcón, A., Balcázar, J., Leaño, C., Licona, J.C., Llanque, O., Vroomans, V., Zuidema, P., et al.. (2011). Climate is a stronger driver of tree and forest growth rates than soil and disturbance. J. Ecol. 99: 254–264, https://doi.org/10.1111/j.1365-2745.2010.01741.x.Search in Google Scholar
Tomczak, K., Tomczak, A., and Jelonek, T. (2022). Measuring radial variation in basic density of pendulate oak: comparing increment core samples with the IML power drill. Forests 13: 589, https://doi.org/10.3390/f13040589.Search in Google Scholar
Torelli, N. and Gorišek, Ž. (1995). Mexican tropical hardwoods – dimensional stability. Eur. J. Wood Prod. 53: 277–280, https://doi.org/10.1007/s001070050090.Search in Google Scholar
Van der Merwe, J.-P., Germishuizen, I., Clarke, C., and Mansfield, S.D. (2023a). The impact of soil, altitude, and climate on tree form and wood properties of plantation grown Pinus patula in Mpumalanga, South Africa. Holzforschung 77: 1–15, https://doi.org/10.1515/hf-2022-0126.Search in Google Scholar
Van der Merwe, J.-P., Wang, T., Clarke, C., and Mansfield, S.D. (2023b). Predicting temperature and rainfall for plantation forestry in Mpumalanga, South Africa, using locally developed climate models. Agric. For. Meteorol. 329: 109275, https://doi.org/10.1016/j.agrformet.2022.109275.Search in Google Scholar
Van Wilgen, B.W. and Richardson, D.M. (2012). Three centuries of managing introduced conifers in South Africa: benefits, impacts, changing perceptions and conflict resolution. J. Environ. Manage. 106: 56–68, https://doi.org/10.1016/j.jenvman.2012.03.052.Search in Google Scholar PubMed
Van Zonneveld, M., Jarvis, A., Dvorak, W., Lema, G. and Leibing, C. (2009). Climate change impact predictions on Pinus patula and Pinus tecunumanii populations in Mexico and Central America. For. Ecol. Manage. 257: 1566–1576, https://doi.org/10.1016/j.foreco.2008.12.027.Search in Google Scholar
Wang, Y., Titus, S.J., and LeMay, V.M. (1998). Relationships between tree slenderness coefficients and tree or stand characteristics for major species in boreal mixedwood forests. Can. J. For. Res. 28: 1171–1183, https://doi.org/10.1139/x98-092.Search in Google Scholar
Warensjö, M. and Rune, G. (2004). Stem straightness and compression wood in a 22-year-old stand of container-grown Scots Pine trees. Silva Fenn 38: 143–153, https://doi.org/10.14214/sf.424.Search in Google Scholar
Watts, S. (2006). Strategic developments in natural forest conservation in South Africa. J. Sustain. For. 22: 77–109, https://doi.org/10.1300/j091v22n03_06.Search in Google Scholar
Wei, T. and Simko, V. (2021). R package ‘corrplot’: visualization of a correlation matrix. Version 0.92.Search in Google Scholar
Wessels, C.B., Malan, F.S., Kidd, M., and Rypstra, T. (2015). The variation of microfibril angle in South African grown Pinus patula and its influence on the stiffness of structural lumber. South. For. 77: 213–219, https://doi.org/10.2989/20702620.2015.1031575.Search in Google Scholar
White, D.A., Ren, S., Mendham, D.S., Balocchi-Contreras, F., Silberstein, R.P., Meason, D., Iroumé, A., and Ramirez de Arellano, P. (2022). Is the reputation of Eucalyptus plantations for using more water than Pinus plantations justified? Hydrol. Earth. Syst. Sci. 26: 5357–5371, https://doi.org/10.5194/hess-26-5357-2022.Search in Google Scholar
Wimmer, R. and Johansson, M. (2014). Effects of reaction wood on the performance of wood and wood-based products. In: Gardiner, B., Barnett, J., Saranpää, P., and Gril, J. (Eds.). The biology of reaction wood. Springer series in wood science. Springer, Berlin/Heidelberg, pp. 225–248.10.1007/978-3-642-10814-3_8Search in Google Scholar
Xu, J., LuBao, F., Evans, R., and Downes, G.M. (2013). Climate response of cell characteristics in tree rings of Picea crassifolia. Holzforschung 67: 217–225, https://doi.org/10.1515/hf-2011-0144.Search in Google Scholar
Yandell, B.S. (1997). Practical data analysis for designed experiments. Chapman & Hall, Madison, USA.10.1007/978-1-4899-3035-4Search in Google Scholar
Zhang, X., Wang, H., Chhin, S., and Zhang, J. (2020). Effects of competition, age and climate on tree slenderness of Chinese fir plantations in southern China. For. Ecol. Manage. 458: 117815, https://doi.org/10.1016/j.foreco.2019.117815.Search in Google Scholar
Zhao, D., Bullock, B.P., Montes, C.R., Wang, M., Westfall, J., and Coulston, J.W. (2020). Long-term dynamics of loblolly pine crown structure and aboveground net primary production as affected by site quality, planting density and cultural intensity. For. Ecol. Manage. 472: 118259, https://doi.org/10.1016/j.foreco.2020.118259.Search in Google Scholar
Supplementary Material
This article contains supplementary material (https://doi.org/10.1515/hf-2023-0031).
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