DIAMETER INCREMENT ESTIMATIONS OF Pinus brutia Ten. FORESTS STAND OF DUHOK GOVERNORATE, KURDISTAN REGION, IRAQ

Authors

  • Abdulaziz Jameel Younis Department of Forestry, College of Agricultural Engineering Science, University of Duhok, Duhok, Iraq
  • Tariq Kurko Salih Department of Forestry, College of Agricultural Engineering Science, University of Duhok, Duhok, Iraq.

DOI:

https://doi.org/10.25271/sjuoz.2025.13.4.1581

Keywords:

Diameter increment estimating, Duhok governorate, Pinus brutia, Statistical model

Abstract

Pinus brutia Ten., a native eastern Mediterranean conifer, is prominent in northern Iraq and has enormous importance in the stability of ecosystems, biodiversity, and landscape protection. This study was conducted on Calabrian pine populations sampled from three ecologically differentiated sites in Duhok Province, Kurdistan Region, Iraq. Fifteen trees were selected, five per site, four of which will be used in a model calibration and one will be used for validation. Partial stem analysis was conducted by extracting cross-sections at breast height diameter. Despite the small sample size, the dataset provided sufficient observations for reliable statistical modeling. A systematic model selection framework was employed, incorporating tests of model assumptions, goodness of fit metrics, residual diagnostics, the Salih index to enhance the precision of Ohtomo’s test, R² interpretation, the Furnival index, and the Bias percent test. Allometric regression models were developed using STATGRAPHICS Centurion 19 software, and both homogeneous and heterogeneous forms were assessed. A t-test confirmed the reliability of the calibration models. Site-specific equations were derived based on the best-fitting regression forms: a curvilinear model was selected for both Zawita (Di = 6.2 − 1.2119 × ln(D)) and Atrush (Di = 14.8 − 2.8561 × ln(D)), while a square root transformation yielded the best fit at Belkef (Di = 14.1 − 1.7501 × √D)

Downloads

Download data is not yet available.

References

Abdulqader, H. N., & Obeyed, M. H. (2023). Evaluations of Different Models for Predicting Merchantable Volume of Pinus Brutia Ten. in Duhok Governorate. Science Journal of University of Zakho, 11(2). https://doi.org/10.25271/sjuoz.2023.11.2.997

Amoroso, M. M., Daniels, L. D., Baker, P. J., & Camarero, J. J. (Eds.). (2017). Dendroecology: tree-ring analyses applied to ecological studies (Vol. 231). Springer. https://link.springer.com/book/10.1007/978-3-319-61669-8

Babst, F., Bouriaud, O., Poulter, B., Trouet, V., Girardin, M. P., & Frank, D. C. (2019). "Twentieth century redistribution in climatic drivers of global tree growth." Science Advances, 1(1), e1500088. http://dx.doi.org/10.1126/sciadv.aat4313

Beram, A. (2023). Improved performance of Brutian pine wood via impregnation with nanoclay. BioResources, 18(4), 8076. DOI: 10.15376/biores.18.4.8076-8089

Binkley, D., Stape, J. L., Ryan, M. G., Barnard, H. R., & Fownes, J. (2002). "Age-related decline in forest ecosystem growth: an individual-tree, stand-structure hypothesis." Ecosystems, 5(1), 58-67. https://doi.org/10.1007/s10021-001-0055-7

Biondi, F., & Qeadan, F. (2008). A theory-driven approach to tree-ring standardization: defining the biological trend from expected basal area increment. Tree-Ring Research, 64(2), 81-96. https://doi.org/10.3959/2008-6.1

Bontemps, J.-D., & Esper, J. (2011). Statistical modelling and RCS detrending methods provide similar results on tree-ring based long-term growth trends. Dendrochronologia, 29(2), 143–151. https://doi.org/10.1016/j.dendro.2010.09.002

Bourian, D., Guibal, F., & Tessier, L. (2005). Long-term growth trends in temperate forests in southern France. Forest Ecology and Management, 214(1-3), 131–145.

Boydak, M. (2004). Silvicultural characteristics and natural regeneration of Pinus brutia Ten.—a review. Plant Ecology, 171, 153-163. https://doi.org/10.1023/B:VEGE.0000029373.54545.d2

Brack and Wood, (1997). Forest Mensuration and Modelling. Available online at INDEX: Forest Mensuration Resources (anu.edu.au)

Bräker, O. U. (2002). "Measuring and data processing in tree-ring research—A methodological introduction." Dendrochronologia, 20(1-2), 203–216. https://doi.org/10.1078/1125-7865-00017

Brienen, R. J. W., et al. (2015). Long-term decline of the Amazon carbon sink. Nature, 519(7543), 344–348. https://doi.org/10.1038/nature14283

Brunner, I., Herzog, C., Dawes, M. A., Arend, M., & Sperisen, C. (2015). "How tree roots respond to drought." Frontiers in Plant Science, 6, 547. https://doi.org/10.3389/fpls.2015.00547

Cook, E. R., & Kairiukstis, L. A. (1990). Methods of Dendrochronology: Applications in the Environmental Sciences. Springer ISBN 0-7923-0586-8

Edvardsson, J., & Hansson, K. (2015). Dendrochronological potential and growth response of Scots pine to drainage in peatlands. Scandinavian Journal of Forest Research, 30(7), 574–582.

Forrester, D. I., et al. (2017). Generalized biomass and leaf area allometric equations for European tree species. Forest Ecology and Management, 396, 17–32. https://doi.org/10.1016/j.foreco.2017.04.011

Furnival, G. M. (1961). "An index for comparing equations used in constructing volume tables." Forest Science, 7(4), 337–341.

Goude, M. (2022). Modeling basal area growth using transformed predictors in boreal forests. Forest Ecosystems, 9, 15. https://doi.org/10.1186/s40663-022-00357-2

Hordo, M. (2011). Application of dendroclimatological methods for forest growth modelling. Eesti Maaülikool. ISBN 978-9949-426-99-7

Karikuki, M., (2002). Height estimation in complete stem analysis using annual radial growth measurements. Forestry, 75(1), pp.63-74. https://doi.org/10.1093/forestry/75.1.63

Köhl, M., Lasco, R., Cifuentes, M., Jonsson, R., Korhonen, K. T., Mundhenk, P., Neupane, P. R., & Teobaldelli, M. (2015). Changes in forest production, biomass and carbon: Results from the 2015 Global Forest Resources Assessment. https://doi.org/10.1016/j.foreco.2015.05.036

Krishnankutty, C. N. (2013). Volume tables for trees in home gardens of Kerala. Indian Forester, 139(7), 652-657

Larson, P. R. (1963). Stem form development of forest trees. Forest science, 9(suppl_2), a0001-42.

Lindenmayer, D. B., Laurance, W. F., & Franklin, J. F. (2012). "Global decline in large old trees." Science, 338(6112), 1305-1306. http://dx.doi.org/10.1126/science.1231070

Montgomery, Douglas C., and George C. Runger. Applied statistics and probability for engineers. John wiley & sons, 2019. ISBN: 978-1-119-40036-3

Moore, D. S. (2010). The basic practice of statistics. Palgrave Macmillan. ISBN-13:978-1-4292-0121-6

Morales-Molino, C., Arianoutsou, M., Torres Galán, I., & Moreno Rodríguez, J. M. (2021). Ecosystem Services Provided by Pine Forests. https://doi.org/10.1007/978-3-030-63625-8_29

Mosa, W. L. (2016). Forest cover change and migration in Iraqi Kurdistan: a case study from Zawita Sub-district. Michigan State University. https://doi.org/doi:10.25335/8nae-7e42

Neter, J., Kutner, M.H., Nachtsheim, C.J. and Wasserman, W., 1996. Applied linear statistical models.

Peel, M. C., Finlayson, B. L., & McMahon, T. A. (2007). Updated world map of the Köppen-Geiger climate classification. Hydrology and Earth System Sciences Discussions, 4(2), 439–473. https://doi.org/10.5194/hessd-4-439-2007

Pienaar, L. V., & Turnbull, K. J. (1973). The Chapman-Richards generalization of von Bertalanffy’s growth model for basal area growth and yield in even-aged stands.

Forest Science, 19(1), 2-22. https://doi.org/10.1093/forestscience/19.1.2

Pretzsch, H., M. del Río, F. Giammarchi, E. Uhl, and R. Tognetti (2022). "Changes of tree and stand growth: review and implications." Climate-smart forestry in mountain regions :189-222. http://dx.doi.org/10.1007/978-3-030-80767-2_6

Saeed, H., (2023). The use of complete stem analysis in biometrical studies of Calabrian Pine trees growth in Duhok Governorate region of Iraq. Master’s thesis, University of Duhok.

Salih, T. K., (2020). Growth functions modeling of Quercus aegilops L. and dendroclimatological Analysis of Pinus brutia Ten. In Duhok Governorate (submitted to the Council of the college of agricultural Sciences, Duhok university) PhD dissertation. University of Duhok.

Salih, T. K., Saleem, G. Y., & Younis, A. J. (2023). Comparison between linear and non-linear regression models in the prediction of the height of Gall Oak trees (Quercus infectoria Olive.) in Duhok Governorate. doi:10.1088/1755-1315/1213/1/012118

Salih, T. K., Younis, M. S., & Wali, S. T. (2021, November). Allometric regression equations between diameter growth and age of valonia oak trees grown in Duhok province, Iraq. In International Hasankeyf Scientific Research and Innovation Congress (pp. 557-576).

Segura, M., Kanninen, M., & Suárez, D. (2006). Allometric models for estimating aboveground biomass of shade trees and coffee bushes grown together. Agroforestry systems, 68, 143- 150. https://doi.org/10.1007/s10457-006-9005-x

Shahbaz S.E., (2010). Trees and Shrubs, afield guide to the trees and shrubs of Kurdistan region of Iraq, Duhok University.

Söderberg, U. (1986). Funktioner för skogliga produktionsprognoser: Tillväxt och formhöjd för enskilda träd av tall och gran i Sverige [Functions for forest production forecasts: Growth and form height for individual Scots pine and Norway spruce trees in Sweden]. Swedish University of Agricultural Sciences, Reports of the Forest Research Institute, No. 56.

Stephenson, N. L., Das, A. J., Condit, R., Russo, S. E., Baker, P. J., Beckman, N. G., & Coomes, D. A. (2014). "Rate of tree carbon accumulation increases continuously with tree size." Nature, 507(7490), 90-93. http://dx.doi.org/10.1038/nature12914

Thapa, H. B. (1999). Prediction models for above-ground wood of some fast growing trees of Nepal's eastern Terai. Banko Janakari, 9(2), 28-35. DOI: https://doi.org/10.3126/banko.v9i2.17663

Torres, I., Moreno, J. M., Morales-Molino, C., & Arianoutsou, M. (2021). Ecosystem services provided by pine forests. Pines and their mixed forest ecosystems in the Mediterranean Basin, 617-629. http://dx.doi.org/10.1007/978-3-030-63625-8_29

Van Laar, A. and Akça, A., (2007). Forest mensuration (Vol. 13). Springer Science & Business Media. https://doi.org/10.1007/978-1-4020-5991-9

Weiner, J., & Thomas, S. C. (1992). "Competition and allometry in three species of tree seedlings." Ecology, 73(2), 648-658. http://dx.doi.org/10.2307/1940771

Wooldridge, J. M. (2020). Introductory Econometrics: A Modern Approach (7th ed.). Cengage Learning.

YOUNIS, A. J., & HASSAN, M. K. (2019). Assessing volume of Quercus aegilops L. trees in Duhok Governorate, Kurdistan Region of Iraq. Journal of Duhok University, 22(1), 265- 276 http://dx.doi.org/10.26682/avuod.2019.22.1.25

Youssef, S., Galalaey, A., Mahmood, A., Mahdi, H., & Véla, E. (2019). Wild orchids of the Kurdistan Region areas: A scientific window on the unexpected nature of the north-western Zagros. Société Méditerranéenne d’Orchidologie.

Zeide, B. (1993). "Analysis of growth equations." Forest Science, 39(3), 594–616. https://doi.org/10.1093/forestscience/39.3.594

Downloads

Published

2025-10-08

How to Cite

Younis, A. J., & Salih, T. K. (2025). DIAMETER INCREMENT ESTIMATIONS OF Pinus brutia Ten. FORESTS STAND OF DUHOK GOVERNORATE, KURDISTAN REGION, IRAQ. Science Journal of University of Zakho, 13(4), 577–588. https://doi.org/10.25271/sjuoz.2025.13.4.1581

Issue

Vol. 13 No. 4 (2025): October-December issue

Section

Science Journal of University of Zakho

License

Copyright (c) 2025 Abdulaziz Jameel Younis, Tariq Kurko Salih

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Authors who publish with this journal agree to the following terms:

  • Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License [CC BY-NC-SA 4.0] that allows others to share the work with an acknowledgment of the work's authorship and initial publication in this journal.
  • Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work, with an acknowledgment of its initial publication in this journal.
  • Authors are permitted and encouraged to post their work online.