Iranian Journal of Forest

Iranian Journal of Forest

Tree Growth Responses to Climatic Factors: Lessons from Semi-Arid Zagros Oak Forests, Western Iran

Document Type : Research Paper

Authors
Elham Motaharfard 1
Ali Mahdavi 2
Reza Akhavan 3
Asghar Fallah 4
Reza Omidipour 5
Stockton Maxwell 6
1 Ph.D. student of Forest Sciences, Dept. of Forest Sciences, Faculty of Agriculture and Natural Resources, Ilam University, I. R. Iran
2 Prof., Dept. of Forest Sciences, Faculty of Agriculture and Natural Resources, Ilam University, I. R. Iran
3 Associate Prof., Research Institute of Forests and Rangelands, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran
4 Prof., Sari Agriculture Sciences and Natural Resource University, Mazandaran, I. R. Iran
5 Assistant Prof., Dept. of Rangeland and Watershed Management, Faculty of Agriculture, Ilam University, I. R. Iran
6 Prof., Dept. of Geospatial Science, Radford University, P.O. Box 6938, Radford, VA 24142, United States
10.22034/ijf.2025.509829.2046
Abstract
The Zagros forest ecosystem, the largest forested region in Iran, is dominated by Quercus species and characterized by a semi-arid Mediterranean climate. Over the past two decades, increasing temperatures and evapotranspiration have imposed significant stress even on the drought-tolerant Quercus species. In this study, we investigated the climate-growth relationships of Quercus brantii Lindl., a dominant tree species in the western Iranian forest ecosystem. We collected 29 cross-sections from Q. brantii at the Melehpanjab and Pashmin sites for dendrochronological analysis. Generalized additive models (GAMs) were employed to identify radial growth responses and non-linear relationships and to monthly climatic variables, including precipitation and temperature, over the past 18 years (2005-2022). The model explained 66.7% of the variation in ring width. Our findings highlight the sensitivity of Q. brantii to climatic variability, with key drivers of growth being precipitation from October to May (PrcOct_May), precipitation from October to March (PrcOct_Mar), temperature from October to December (TempOct_Sep), and potential evapotranspiration (PET) during spring and summer. Radial growth increased following moist periods (e.g., 2005–2007) but declined during dry periods (e.g., 2007–2010). Q. brantii exhibited a positive response to water availability prior to the growing season, and precipitation - year interactions were significant during moist periods. However, radial growth showed a negative response to elevated temperatures (particularly when average annual temperature exceeded above 22.5°C) and limited summer precipitation, which acted as a critical growth constraint. Tree growth was enhanced by PET during spring (April and May), while low soil moisture in June (linear trend) and July (non-linear trend) restricted growth. In conclusion, moisture availability emerged as the most critical factor influencing the growth of Zagros oak forests, with precipitation acting as the key constraint. Additionally, the application of GAMs provides valuable insights into estimating optimal precipitation and temperature conditions for Q. brantii in this region.
Keywords
Dendrochronology
Zagros forests
Tree-ring
Generalized additive model
 
Ahmadi, H., & Azizzadeh, J. (2020). The impacts of climate change based on regional and global climate models (RCMs and GCMs) projections (case study: Ilam province). Modeling Earth Systems and Environment. https://doi.org/10.1007/s40808-020-00721-0.
Ahmadi, R., Kiadaliri, H., Mataji, A., & babaei-Kafaki, S. (2014). Oak forest decline zonation using AHP model and GIS technique in Zagros Forests of Ilam Province. Journal of Biodiversity and Environmental Sciences, 4(3), 141-150p. http://www.innspub.net.
Arsalani, M. (2012). Reconstruction of Precipitation and Temperature Variations Using Oak Tree Rings in Central Zagros, Iran. Faculty of Geography, University of Tehran, Iran Unpublished M.A. thesis. (In Persian).
Arsalani, M., Azizi, Gh., & Bräuning, A. (2014). Dendroclimatic reconstruction of May–June maximum temperatures in the central Zagros Mountains, western Iran. International Journal of Climatology, 35, 408–416. DOI: 10.1002/joc.3988.
Arsalani, M., Bräuning, A., Pourtahmasi, K., Azizi, Gh., & Mohammadi, H. (2018a). Multiple tree-ring parameters of Quercus brantii Lindel in SW Iran show a strong potential for intra-annual climate reconstruction. Trees, 32, 1531-1546. https://doi.org/10.1007/s00468-018-1731-y.
Arsalani, M., GrieBinger, J., & Bräuning, A. (2022). Tree-ring-based seasonal temperature reconstructions and ecological implications of recent warming on oak forest health in the Zagros Mountains, Iran. International Journal of Biometeorology, 66, 2553–2565. https://doi.org/10.1007/s00484-022-02380-5.
Arsalani, M., Pourtahamsi, K., Azizi, Gh., Bräuning, A., & Mohammadi, H. (2018b). Tree-ring based December–February precipitation reconstruction in the southern Zagros Mountains, Iran. Dendrochronologia, 49, 45–56. https://doi.org/10.1016/j.dendro.2018.03.002.
Attarod, P., Beiranvand, S., Pypker, Th.G., Bayramzadeh, V., Helali, J., Mashayekhi, Z., Fathi, J., & Soofi-Mariv, H. (2023). Are precipitation characteristics and patterns impacting oak trees decline in the Zagros region of western Iran? Caspian Journal of Environmental Sciences, 21(4), 753-765. DOI: 10.22124/CJES.2023.7122. 
Azizi, Gh., Arsalani, M., Bräuning, A., & Moghimi, E. (2013). Precipitation variations in the central Zagros Mountains (Iran) since A.D. 1840 based on oak tree rings. Palaeogeography, Palaeoclimatology, Palaeoecology, 386, 96–103. http://dx.doi.org/10.1016/j.palaeo.2013.05.009.
Bunn, A.G. )2008(. A dendrochronology program library in R (dplR). Dendrochronologia, 26, 115–124. doi:10.1016/j.dendro.2008.01.002.
Bunn, A.G. (2010). Statistical and visual crossdating in R using the dplR library. Dendrochronologia, 28, 251–258. doi:10.1016/j.dendro.2009.12.001.
Camarero, J.J., Campelo, F., Sánchez-Sancho, J.A., & Santana, J.C. (2023).  Mediterranean service trees respond less to drought than oaks. Forest Ecology and Management, 541(2023) 121070. https://doi.org/10.1016/j.foreco.2023.121070.
Campelo, F., Sánchez-Sancho, J.A., Rodrigues-Gonzalez, P.M., Colangelo, M., Sanchez-Miranda, A., Rita, A., Ripullone, F., & Camarero, J.J. (2022). Growth phenological variations in the narrow-leaved ash (Fraxinus angustifolia) over the Mediterranean region: A simulation study.  Dendrochronologia, 76(2022) 126013. https://doi.org/10.1016/j.dendro.2022.126013.
Fattahi, M. (1994). Study on Zagros oak forests and the most important their destruction causes. Institute of Forests and Rangelands Research press, Sanandaj, Iran.
Gadermaier, J., Vospernik, S., Grabner, M., Wächter, E., Keßler, D., Kessler, M., Lehner, F., Klebinder, K., & Katzensteiner, K. (2024). Soil water storage capacity and soil nutrients drive tree ring growth of six European tree species across a steep environmental gradient. Forest Ecology and Management, 554(2024) 121599. https://doi.org/10.1016/j.foreco.2023.121599.
Ghazanfari, H., Namiranian, M., Sobhani, H., & Marvy-Mohajer, M.R. (2004). Traditional Forest Management and its Application to Encourage Public Participation for Sustainable Forest Management in the Northern Zagros Mountains of Kurdistan Province, Iran. Scandinavian Journal of forest Research, 19(4), 65-71. DOI: 10.1080/14004080410034074.
Gonçalves, J.Q., Durgante, F.M., Wittmann, F., Piedade, M.T.F., Rodriguez, D.R.O., Tomazello-Filho, M., Parolin, P., & SchÖngart, J. (2021). Minimum temperature and evapotranspiration in Central Amazonian floodplains limit tree growth of Nectandra amazonum (Lauraceae). Trees, 35, 1367–1384. https://doi.org/10.1007/s00468-021-02126-7.
Hastie, T.J., & Tabshirani, R.J. (1990). Generalized Additive Models. New York 1990.
Henareh Khalyani, A., Mayer, A.L., Falkowski, M.J., & Muralidharan, D. (2012). Deforestation and landscape structure changes related to socioeconomic dynamics and climate change in Zagros forests. Journal of Land Use Science, 8(3), 321–340. http://dx.doi.org/10.1080/1747423X.2012.667451.
Huang, M., Wang, X., Keenan, T.F., & Piao, S. (2018). Drought timing influences the legacy of tree growth recovery. Global Change Biology, 24, 3546–3559. https://doi.org/10.1111/gcb.14294.
Iqbal, S., Zha, T.D., Hayat, M., Khan, A., Ashraf, M.I., Ahmad, B., Saba, N.U., & Jan, S.A. (2020). Spatiotemporal variation and climate change impact on radial growth of chir pine (Pinus Roxburghii) in a subtropical Pine forest in Pakistan. Ecology and Environmental Ressearch, 18(4), 4839–4855. DOI: http://dx.doi.org/10.15666/aeer/1 804_48394855.
Jing, M., Zhu, L., Cherubini, P., Danyang, Y., Zongshan, L., Wang, X., & Liu, Sh. (2022). Responses of radial growth of Pinus massoniana and Castanopsis eyrei to climate change at different elevations in south China. Ecological Indicators, 145(2022) 109602. https://doi.org/10.1016/j.ecolind.2022.109602.
Karim, M. H., Shahraki, A. S., Kiani-Ghalesard, S., & Fahimi, F. (2019). Management challenges and adaptations with climate change in Iran Forests. Caspian Journal of Environmental Sciences, 18(1), 81–91.
Lebourgeois, F., Cousseau, G., & Ducos, Y. (2004). Climate-tree growth relationships of Quercus petraea Mill. stand in the Forest of Bercé (Futaie des Clos, Sarthe, France). Annals of Forest Science, 61(4), 361–372. http://dx.doi.org/10.1051/forest:2004029.
Madani, K. (2014). Water management in Iran: what is causing the looming crisis? Journal of Environmental Science, 4(4), 315–328. https ://doi.org/10.1007/s1341 2-014-0182-z.
Marra, G., & Wood, S.N. (2011). Practical variable selection for generalized additive models. Computational Statistics and Data Analysis, 55, 2372–2387. https://doi.org/10.1016/j. csda.2011.02.004.
Moradi, M.J., Kiadaliri, H., Babaie-Kafaky, S., & Bakhoda, H. (2021). Detection of high potential areas of Persian oak forests decline in Zagros, Iran, using topsis method. Cerne, 27(1). doi:10.1590/01047760202127012640.
Najafi-Harsini, F., Oladi, R., Pourtahmasi, K., Souto-Herrero, M., & Garcia-Gonzalez, I. (2022). Using tree-ring width and earlywood vessel features to study the decline of Quercus brantii Lindl in Zagros forests of Iran. European Journal of Forest Research, 141, 379–393. https://doi.org/10.1007/s10342-022-01450-y.
NCCOI. (2014). Third national communication to UNFCCC. National Climate Change Office of Iran. http://climate-chang e.ir. https ://unfccc.int/sites /default/files /resource/Third National communication IRAN.pdf
Oladi, R., Elzami, E., Pourtahmasi, K., & Brauning, A. (2017). Weather factors controlling growth of Oriental beech are on the turn over the growing season. European Journal of forest Research, 136, 345–356. https://doi. org/ 10.1007/ s10342-​017-​1036-5.
Pedersen, E.J., Miller, D.L., Simpson, G.L., & Ross, N. (2018). Hierarchical generalized additive models: an introduction with mgcv. PeerJ, 7, e6876. https://doi.org/10.7287/peerj.preprints.27320v1.
R Core Team. (2024). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.R-project.org/.
Safari, E., Moradi, H., Seim, A., Yousefpour, R., Mirzakhani, M., Tegel, W., Soosani, J., & Kahle, H.P. (2022). Regional Drought Conditions Control Quercus brantii Lindl. Growth within Contrasting Forest Stands in the Central Zagros Mountains, Iran. Forests, 13, 495. https://doi.org/10.3390/f13040495.
Santos-Malengue, A., Ariza-Mateos, D., Navarro-Cerrillo, R., Cachinero-Vivar, A.M., & Camarero, J.J. (2023). Ring data provide management clues and pinpoint climate drivers of growth in two species of miombo trees (Brachystegia spiciformis, Julbernardia paniculata).  Dendrochronologia, 81(2023) 126117. https://doi.org/10.1016/j.dendro.2023.126117.
Simpson, G.L. (2023). gratia: Graceful ggplot-Based Graphics and Other Functions for GAMs Fitted using mgcv.
Speer, J.H. (2010). Fundamentals of tree-ring research. University of Arizona Press. https://uapress.arizona.edu/book/fundamentals-of-tree-ring-research.
Talebi, M., Sagheb-Talebi, Kh., & Jahanbazi, H. (2006). Site demands and some quantitative and qualitative characteristics of Persian Oak (Quercus brantii Lindl.) in Chaharmahal & Bakhtiari Province (western Iran). Forest & Poplar Research, 14(1), 67–76. (In Persian)
Tang, D. (2020). Plotting Weather Data Using R. [Blog Post]. Available online: https://davetang .org/muse/ 2020/01/08 /plottingweather-data-using-r/.
Thornthwaite, C. W. (1948). An approach toward a rational classification of climate. Geographical Review, 38(1), 55–94. https://doi.org/10.2307/210739.
Valavi, R., Shafizadeh-Moghadam, H., Matkan, A.A., Shakiba, A.R., Mirbagheri, B., & Kia, S.H. (2018). Modelling climate change effects on Zagros forests in Iran using individual and ensemble forecasting approaches. Theoretical and Applied Climatology. https://doi.org/10.1007/s00704-018-2625-z.
Vospernik, S., Heym, M., Pretzsch, H., Pach, M., Steckel, M., Aldea, J., Brazaitis, G., Bravo-Oviedo, A., Del Rio, M., Lof, M., Pardos, M., Bielak, K., Bravo, F., Coll, L., Cerný, J., Droessler, L., Ehbrecht, M., Jansons, A., Korboulewsky, N., Jourdan, M., Nord-Larsen, Th., Nothdurft, A., Ruiz-Peinado, R., Ponette, Q., Sitko, S., Svoboda, M., & Wolff, B. (2023). Tree species growth response to climate in mixtures of Quercus robur/ Quercus petraea and Pinus sylvestris across Europe- a dynamic, sensitive equilibrium. Forest Ecology and Management, 530 (2023) 120753. https://doi.org/10.1016/j.foreco.2022.120753.
Wood, S.N. (2017). Generalized Additive Models: An Introduction with R, second ed. Chapman and Hall/CRC. https://doi.org/10.1201/9781315370279.
Yuan, W., Zheng, Y., Piao, S., Ciais, P., Lombardozzi, D., Wang, Y., Ryu, Y., Chen, G., Dong, W., & Hu, Z. (2019). Increased atmospheric vapor pressure deficit reduces global vegetation growth. Science Advance, 5(8):eaax1396. doi: 10.1126/sciadv.aax1396
Zang, C., Hartl-Meier, C., Dittmar, C., Rothe, A., & Menzel, A. (2014). Patterns of drought tolerance in major European temperate forest trees: Climatic drivers and levels of variability. Global Change Biology, 20(12), 3767–3779. https://doi.org/10.1111/gcb.12637
Zarean, H., Yazdanpanah, H., Movahedi, S., Jalilvand, H., Momeni, M., & Yarali, N. (2014). Chronological Study of Quercus Persica Growth Ring Response to Climatic Variables of Precipitation and Temperature in Zagros Forests (A Case Study of Dena Region).  Journal of Biological Dynamics, 4(4), 247–255.
Zarenistanak, M., Dhorde, A.G., & Kripalani, R.H. (2014). Temperature analysis over southwest Iran: trends and projections. Theoretical and Applied Climatology, 116, 103–117. DOI 10.1007/s00704-013-0913-1.
Iranian Journal of Forest
Volume 16, Issue 5
Winter 2025
Pages 99-114

  • Receive Date 30 May 2024
  • Revise Date 23 January 2025
  • Accept Date 13 March 2025