Influence of Physical and Environmental Factors on Yield Prediction Variability in Sri Lankan Pinus Plantations. P. 9–19

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DOI:

10.37482/0536-1036-2026-4-9-19

Abstract

This study investigates the influence of slope and agro-ecological regions on the growth and timber volume of Pinus plantations in the wet and intermediate zones of Sri Lanka. Annually, the Forest Department of Sri Lanka releases approximately 1,000 hectares of Pinus plantations for thinning and clear felling to the State Timber Corporation, which estimates timber yield using enumeration data. Notable discrepancies between estimated and actual timber volumes prompted a detailed analysis of the physical and environmental factors affecting plantation growth. The study covered 48 coupes from 11 plantations across three districts Nuwara Eliya, Matara, and Ratnapura selected based on regional representation. Data collected included actual timber volumes extracted in 2020 and 2021, slope measurements, standing tree counts, and agro-ecological region classifications. Statistical analysis focused on identifying correlations between slope, agro-ecological regions, and recorded timber volume. Results indicated a predominantly negative correlation between slope and timber volume, with volumes decreasing progressively from up-country to low-country regions. Steeper slopes were consistently associated with reduced timber yields, while agro-ecological zone significantly influenced overall plantation productivity across all sampled sites. These findings highlight the importance of incorporating topographical and ecological factors into timber yield forecasting models. Improved integration of such variables would reduce estimation discrepancies, support more accurate harvest planning, and contribute to the long-term sustainable management of forest plantation resources across Sri Lanka.

Authors

Gihan Amila Kumarasekara¹, PhD; ORCID: https://orcid.org/0009-0009-7045-4685
Chaminda Muthumala¹, PhD; ORCID: https://orcid.org/0000-0001-9358-7717
Tharindu Dilan Amarasinghe², PhD; ORCID: https://orcid.org/0000-0001-6073-8275
Faiz Marikar^3*, Director; ORCID: https://orcid.org/0000-0003-4579-7263

Affiliation

¹Research Development and Training Division, State Timber Corporation, Battaramulla, Sri Lanka; kumara@stc.ac.lk, ck_muthumala@yahoo.com
²Department of Natural Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan; amarasinghe@uot.edu.jp
³General Sir John Kotelawala Defence University, Ratmalana, Sri Lanka; faiz@kdu.ac.lk

Keywords

pine, Pinus, Pinus growth, slope impact on wood increment, agro-ecological regions, timber volume, Sri Lankan plantations

For citation

Kumarasekara G.A., Muthumala Ch., Amarasinghe T.D., Marikar F. Influence of Physical and Environmental Factors on Yield Prediction Variability in Sri Lankan Pinus Plantations. Lesnoy Zhurnal = Russian Forestry Journal, 2026, no. 4, pp. 9–19. (In Russ.). https://doi.org/10.37482/0536-1036-2026-4-9-19

References

1. Ashton P.M.S., Gamage S., Gunatilleke I.A.U.N., Gunatilleke C.V.S. Restoration of a Sri Lankan Rainforest: Using Caribbean Pine Pinus caribaea as a Nurse for Establishing Late-Successional Tree Species. Journal of Applied Ecology, 1997, vol. 34, no. 4, pp. 915–925. https://doi.org/10.2307/2405282

2. D’Amato A.W., Jokela E.J., O’Hara K.L., Long J.N. Silviculture in the United States: An Amazing Period of Change over the Past 30 Years. Journal of Forestry, 2018, vol. 116, iss. 1, pp. 55–67. https://doi.org/10.5849/JOF-2016-035

3. Dilrukshi R.P.W.A., Hettiarachchi M.H.S.M., Sriskumar S., Chandrasekara E.D.C.T., Dissanayake D.M.M.R., Wijerathna R.M.S. Precision Agricultural Technologies for Enhancing Crop Productivity: A Way Forward to Sri Lankan Agriculture. Sri Lanka Journal of Food and Agriculture, 2021, vol. 7, iss. 2, pp. 23–42. https://doi.org/10.4038/sljfa.v7i2.98

4. Eshetu M., Wogi L., Demissie N. Soil Fertility Assessment and Mapping under Different Land Use Types Along Toposequence at Danka Watershed in Dinsho Districts of Bale Highland Oromia, Southeastern Ethiopia. International Journal of Plant & Soil Science, 2024, vol. 36, iss. 5, pp. 847–872. https://doi.org/10.9734/IJPSS/2024/v36i54582

5. Hearath H.M.B.S., Pushpakumara D.K.N.G., Hewson M., Wickramagamage P. A Geospatial and Socio-Economic Assessment of Tree Density in Home Gardens as Trees Outside Forests Sources in Agro-Ecological Regions: Upper Mahaweli Catchment, Sri Lanka. Tropical Agricultural Research, 2023, vol. 34, iss. 3, pp. 212–226. https://doi.org/10.4038/tar.v34i3.8647

6. Jayawardhane J., Gunaratne A.M.T.A. Restoration Success Evaluation of a Thinned and Enriched Pine Plantation in Sri Lanka. Journal of Tropical Forest Science, 2020, vol. 32(4), pp. 402–413. https://doi.org/10.26525/jtfs2020.32.4.402

7. Karunaratne A.S., Wimalasiri E.M., Piyathilake U., Gunatilake S.K., Muttil N., Rathnayake U. Modelling Potential Soil Erosion and Sediment Delivery Risk in Plantations of Sri Lanka. Soil Systems, 2022, vol. 6, iss. 4, art. 97. https://doi.org/10.3390/soilsystems6040097

8. Kim J., Ahn J., Kang J. Analysis of Wildfire Spread and Development of Efficient Adaptation Plan for Natural Recreation Forests: A Case Study of Gangwon-Do, South Korea. South Korea, 2023. 44 p. http://dx.doi.org/10.2139/ssrn.4581281

9. Liu J. Progress in Research on the Effects of Environmental Factors on Natural Forest Regeneration. Frontiers in Forests and Global Change, 2025, vol. 8, art. 1525461. https://doi.org/10.3389/ffgc.2025.1525461

10. Malaviarachchi M.A., Karunathilake W.A., Perera R.A., Nijamudeen M.S. Threats and Related Research Towards Adaptation of Other Field Crops to Climate Change in the Dry Zone of Sri Lanka. Proceedings of the Workshop on Present Status of Research Activities on Climate Change Adaptations. Ed. by B. Marambe. Colombo, Sri Lanka, Council for Agricultural Research Policy, 2019, pp. 21–29.

11. Muthumala C.K., De Silva S., Alwis P.L.A.G., Arunakumara I.K.K.U., Marikar F.M.M.T. Assessment of Quality Parameters of Finger-Jointed Timber Products: A Review. Bulletin of the Transilvania University of Brasov. Series II, 2025, vol. 18(67), pp. 65–82. https://doi.org/10.31926/but.fwiafe.2025.18.67.1.5

12. Nandasena W.D.K.V., Brabyn L., Serrao-Neumann S. Monitoring Invasive Pines Using Remote Sensing: A Case Study from Sri Lanka. Environmental Monitoring and Assessment, 2023, vol. 195, art. 347. https://doi.org/10.1007/s10661-023-10919-1

13. Rishmawi K., Huang C., Zhan X. Monitoring Key Forest Structure Attributes Across the Conterminous United States by Integrating GEDI LiDAR Measurements and VIIRS Data. Remote Sensing, 2021, vol. 13(3), art. 442. https://doi.org/10.3390/rs13030442

14. Smith N.J.Р., Williams J.T., Plucknett D.L., Talbot J.P. Tropical Forests and Their Crops. Ithaca, Cornell University Press, 2018. 584 p.

15. Sri Lanka Forestry Sector Master Plan (FSMP). Battaramulla, Sri Lanka, Forestry Planning Unit, Ministry of Agriculture, Lands & Forestry, 1995.

16. Subasinghe S.M.C.U.P., Haripriya A.M.R. Prediction of Stem Biomass of Pinus caribaea Growing in the Low Country Wet Zone of Sri Lanka. Journal of Tropical Forestry and Environment, 2014, vol. 4, no. 1, pp 40–49. https://doi.org/10.31357/jtfe.v4i1.1056

17. Zhang C., Zeng F., Zeng Z., Du H., Su L., Zhang L., et al. Impact of Selected Environmental Factors on Variation in Leaf and Branch Traits on Endangered Karst Woody Plants of Southwest China. Forests, 2022, vol. 13(7), art. 1080. https://doi.org/10.3390/f13071080

18. Zhang X., Ke S., Xu T., Qiao D. Review of China’s Forestry Industry over the Past 70 Years and an Outlook for the Future. International Forestry Review, 2020, vol. 22(2), pp. 269–282. https://doi.org/10.1505/146554820829403496

19. Zhang Y., Wang X.-P., Pan Y., Hu R., Chen N. Global Quantitative Synthesis of Effects of Biotic and Abiotic Factors on Stemflow Production in Woody Ecosystems. Global Ecology and Biogeography, 2021, vol. 30(8), pp. 1713–1723. https://doi.org/10.1111/geb.13322

20. Zhang Z., Du X., Wang F. Biological Activities of Procyanidins from the Bark of Pinus caribaea Morelet. Natural Product Research, 2009, vol. 23(8), pp. 696–703. https://doi.org/10.1080/14786410802242984