Vol. 81 No. 2s (2026): Conference Proceedings Old-Growth Forests and Ancient Trees: A Treasure of Nature, Life and Culture, Firenze 1 October 2025 / Vallombrosa 2-3 October 2025
Articles

An allometric-functional approach to studying the ecological complexity of old-growth forests

PDF (Italiano)
  • Tommaso Anfodillo,
  • Gaia Pasqualotto,
  • Marco Carrer,
  • Amos Maritan
Tommaso Anfodillo
Dipartimento Territorio e Sistemi Agro-Forestali, Università di Padova; viale dell’Università 16 - 35020 Legnaro (PD), Italia.
Gaia Pasqualotto
Dipartimento Territorio e Sistemi Agro-Forestali, Università di Padova; viale dell’Università 16 - 35020 Legnaro (PD), Italia.
Marco Carrer
Dipartimento Territorio e Sistemi Agro-Forestali, Università di Padova; viale dell’Università 16 - 35020 Legnaro (PD), Italia.
Amos Maritan
Dipartimento di Fisica e Astronomia “Galileo Galilei”, Università di Padova; via F. Marzolo 8 - 35131 Padova, Italia.
DOI: https://doi.org/10.36253/ifm-1214

Published 2026-10-06

Keywords

  • energetic equivalence,
  • H-model,
  • diametric distribution,
  • statistical mechanics

How to Cite

Anfodillo, T., Pasqualotto, G., Carrer, M., & Maritan, A. (2026). An allometric-functional approach to studying the ecological complexity of old-growth forests. L’Italia Forestale E Montana, 81(2s), 105–117. https://doi.org/10.36253/ifm-1214

Copyright (c) 2026 Tommaso Anfodillo, Gaia Pasqualotto, Marco Carrer, Amos Maritan

Creative Commons License

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

Abstract

Old-growth forests represent complex ecological systems in which community structure emerges from the interaction of long-term processes operating under conditions of limited disturbance and near-saturation use of available resources. As such, they constitute fundamental reference systems for understanding forest functioning and for testing ecological models grounded in general principles. This study presents a methodological framework to describe and predict the structure of old-growth forests based on individual-level allometric relationships, under the assumption that the forest community fully exploits the available resources. By using crown volume as a proxy for individual resource use, and assuming complete resource utilization at the community level, we show that the diameter distribution emerges as a direct consequence of individual scaling laws and converges toward a distribution consistent with the Energetic Equivalence Principle (EEP). The approach, grounded in the so-called H-model, allows the slope of diameter (or height) distributions to be interpreted as a quantitative metric of old-growthness, disturbance intensity, and successional stage. Old-growth forests are thus proposed as functional reference systems for the study of ecological complexity and for the development of forest management strategies aligned with the principles of closer-to-nature silviculture.

PDF (Italiano)

References

  1. lessandrini, A., Biondi, F., Di Filippo, A., Ziaco, E., & Piovesan, G. (2011). Tree size distribution at increasing spatial scales converges to the rotated sigmoid curve in two old-growth beech stands of the Italian Apennines. Forest Ecology and Management, 262(11), 1950–1962. https://doi.org/10.1016/j.foreco.2011.08.025
  2. Anfodillo, T. (2005). Invecchiamento e senescenza negli alberi: nuove evidenze e nuove domande. Forest@, 2(4), 316–318. https://doi.org/10.3832/efor0327-0002
  3. Anfodillo, T., Carraro, V., Carrer, M., Fior, C., & Rossi, S. (2006). Convergent tapering of xylem conduits in different woody species. New Phytologist, 169(2), 279–290. https://doi.org/10.1111/j.1469-8137.2005.01587.x
  4. Anfodillo, T., Carrer, M., Simini, F., Popa, I., Banavar, J. R., & Maritan, A. (2013). An allometry-based approach for understanding forest structure, predicting tree-size distribution and assessing the degree of disturbance. Proceedings of the Royal Society B: Biological Sciences, 280(1751), 20122375. https://doi.org/10.1098/rspb.2012.2375
  5. Anfodillo, T., & Olson, M. E. (2024). Stretched sapwood, ultra-widening permeability, and ditching da Vinci: revising models of plant form and function. Annals of Botany, 134(1), 19–42. https://doi.org/10.1093/aob/mcae054
  6. Anfodillo, T., & Pasqualotto, G. (2025). Definition of target structure and disturbance intensity. In Protocols for the management and conservation enhancement of forest habitats of the mediterranean region (pp. 21–22). Compagnia delle Foreste. lifegoproformed.eu
  7. Bauhus, J., Puettmann, K., & Messier, C. (2009). Silviculture for old-growth attributes. Forest Ecology and Management, 258(5), 525–537. https://doi.org/10.1016/j.foreco.2009.01.053
  8. Brown, J. H., Gillooly, J. F., Allen, A. P., Savage, V. M., & West, G. B. (2004). Toward a metabolic theory of ecology. Ecology, 85(7), 1771–1789. https://doi.org/10.1890/03-9000
  9. Coomes, D. A. (2006). Challenges to the generality of WBE theory. Trends in Ecology & Evolution, 21(11), 593–596. https://doi.org/10.1016/j.tree.2006.09.002
  10. Coomes, D. A., Duncan, R. B., Allen, R. B., & Truscott, J. (2003). Disturbances prevent stem size-density distributions in natural forests from following scaling relationships. Ecology Letters, 6(12), 980–989. https://doi.org/10.1046/j.1461-0248.2003.00520.x
  11. Damuth, J. (1981). Population density and body size in mammals. Nature, 290(5808), 699–700. https://doi.org/10.1038/290699a0
  12. Damuth, J. (2007). A macroevolutionary explanation for energy equivalence in the scaling of body size and population density. The American Naturalist, 169(5), 621–631. https://doi.org/10.1086/513495
  13. Di Filippo, A., Biondi, F., Piovesan, G., & Ziaco, E. (2017). Tree ring-based metrics for assessing old-growth forest naturalness. Journal of Applied Ecology, 54(3), 737–49. https://doi.org/10.1111/1365-2664.12793
  14. Enquist, B. J. (2002). Universal scaling in tree and vascular plant allometry: toward a general quantitative theory linking plant form and function from cells to ecosystems. Tree Physiology, 22(15–16), 1045–1064. https://doi.org/10.1093/treephys/22.15-16.1045
  15. Farrior, C. E., Bohlman, S. A., Hubbell, S., & Pacala, S. W. (2016). Dominance of the suppressed: Power-law size structure in tropical forests. Science, 351(6269), 155–157. https://doi.org/10.1126/science.aad0592
  16. Garbarino, M., Borgogno Mondino, E., Lingua, E., Nagel, T. A., Dukić, V., Govedar, Z., & Motta, R. (2012). Gap disturbances and regeneration patterns in a Bosnian old-growth forest: a multispectral remote sensing and ground-based approach. Annals of Forest Science, 69(5), 617–625. https://doi.org/10.1007/s13595-011-0177-9
  17. Hooper, D. U., & Vitousek, P. M. (1997). The effects of plant composition and diversity on ecosystem processes. Science, 277(5330), 1302–1305. https://doi.org/10.1126/science.277.5330.1302
  18. Lanner, R. M., & Connor, K. F. (2001). Does bristlecone pine senesce? Experimental Gerontology, 36(4–6), 675–685. https://doi.org/10.1016/S0531-5565(00)00234-5
  19. Lechthaler, S., Kiorapostolou, N., Pitacco, A., Anfodillo, T., & Petit, G. (2020). The total path length hydraulic resistance according to known anatomical patterns: What is the shape of the root-to-leaf tension gradient along the plant longitudinal axis? Journal of Theoretical Biology, 502, 110369. https://doi.org/10.1016/j.jtbi.2020.110369
  20. Loubota Panzou, G. J., Fayolle, A., Jucker, T., Phillips, O. L., Bohlman, S., Banin, L. F., Affum-Baffoe, K., Alves, L. F., Antin, C., Arets, E., Arroyo, L., Baker, T. R., Barbier, N., Beeckman, H., Berger, U., Bocko, Y. E., Bongers, F., Bowers, S., Brade, T., . . . Feldpausch, T. R. (2021). Pantropical variability in tree crown allometry. Global Ecology and Biogeography, 30(2), 459–475. https://doi.org/10.1111/geb.13231
  21. Maritan, A., Rinaldo, A., Rigon, R., Giacometti, A., & Rodríguez-Iturbe, I. (1996). Scaling laws for river networks. Physical Review E, 53(2), 1510–1515. https://doi.org/10.1103/PhysRevE.53.1510
  22. Mikoláš, M., Piovesan, G., Ahlström, A., Donato, D. C., Gloor, R., Hofmeister, J., Keeton, W. S., Muys, B., Sabatini, F. M., Svoboda, M., & Kuemmerle, T. (2023). Protect old-growth forests in Europe now. Science, 380(6644), 466. https://doi.org/10.1126/science.adh2303
  23. Motta, R. (2002). Old-growth forests and silviculture in the Italian Alps: The case-study of the strict reserve of Paneveggio (TN). Plant Biosystems, 136(2), 223–231. https://doi.org/10.1080/11263500212331351129
  24. Muller-Landau, H. C., Condit, R. S., Chave, J., Thomas, S. C., Bohlman, S. A., Bunyavejchewin, S., Davies, S., Foster, R., Gunatilleke, S., Gunatilleke, N., Harms, K. E., Hart, T., Hubbell, S. P., Itoh, A., Kassim, A. R., LaFrankie, J. V., Lee, H. S., Losos, E., Makana, J.-R., . . . Ashton, P. (2006). Testing metabolic ecology theory for allometric scaling of tree size, growth and mortality in tropical forests. Ecology Letters, 9(5), 575–588. https://doi.org/10.1111/j.1461-0248.2006.00904.x
  25. Olson, M. E., Anfodillo, T., Gleason, S. M., & McCulloh, K. A. (2020). Tip-to-base xylem conduit widening as an adaptation: Causes, consequences, and empirical priorities. New Phytologist. https://doi.org/10.1111/nph.16961
  26. Olson, M. E., Anfodillo, T., Rosell, J. A., Petit, G., Crivellaro, A., Isnard, S., León-Gómez, C., Alvarado-Cárdenas, L. O., & Castorena, M. (2014). Universal hydraulics of the flowering plants: Vessel diameter scales with stem length across angiosperm lineages, habits and climates. Ecology Letters, 17(8), 988–997. https://doi.org/10.1111/ele.12302
  27. Pasqualotto, G., Anfodillo, T., Pellizzari, S., Carraro, V., Airi, M., Miozzo, M., & Buscarini, S. (2025). Operationalizing closer-to-nature forest management: Application of the energy-equivalence principle in a Holm Oak (Quercus ilex L.) Mediterranean forest. Forest Ecology and Management, 588, 122735. https://doi.org/10.2139/ssrn.5126751
  28. Petit, G., Anfodillo, T., & Mencuccini, M. (2008). Tapering of xylem conduits and hydraulic limitations in sycamore (Acer pseudoplatanus) trees. New Phytologist, 177(3), 653–664. https://doi.org/10.1111/j.1469-8137.2007.02291.x
  29. Pretzsch, H., & Dieler, J. (2012). Evidence of variant intra- and interspecific scaling of tree crown structure and relevance for allometric theory. Oecologia, 169(3), 637–649. https://doi.org/10.1007/s00442-011-2240-5
  30. Rizzolo, R. (2016). Fuel models development to support spatially-explicit forest fire modelling in Eastern Italian Alps (Tesi di dottorato). Università di Padova.
  31. Sellan, G., Simini, F., Maritan, A., Banavar, J. R., De Haulleville, T., Bauters, M., Doucet, J., Beeckman, H., & Anfodillo, T. (2017). Testing a general approach to assess the degree of disturbance in tropical forests. Journal of Vegetation Science, 28(3), 659–668. https://doi.org/10.1111/jvs.12512
  32. Simini, F., Anfodillo, T., Carrer, M., Banavar, J. R., & Maritan, A. (2010). Self-similarity and scaling in forest communities. Proceedings of the National Academy of Sciences, 107(17), 7658–7662. https://doi.org/10.1073/pnas.1000137107
  33. Stephenson, N. L., Das, A. J., Condit, R., Russo, S. E., Baker, P. J., Beckman, N. G., Coomes, D. A., Lines, E. R., Morris, W. K., Rüger, N., Álvarez, E., Blundo, C., Bunyavejchewin, S., Chuyong, G., Davies, S. J., Duque, Á., Ewango, C. N., Flores, O., Franklin, J. F., . . . Zavala, M. A. (2014). Rate of tree carbon accumulation increases continuously with tree size. Nature, 507(7490), 90–93. https://doi.org/10.1038/nature12914
  34. Susmel, L. (1980). Normalizzazione delle foreste alpine: Basi ecosistemiche, equilibrio, modelli colturali, produttività. Liviana Editrice.
  35. West, G. B., Brown, J. H., & Enquist, B. J. (1999). A general model for the structure and allometry of plant vascular systems. Nature, 400(6745), 664–667. https://doi.org/10.1038/23251
  36. West, G. B., Enquist, B. J., & Brown, J. H. (2009). A general quantitative theory of forest structure and dynamics. Proceedings of the National Academy of Sciences, 106(17), 7040–7045. https://doi.org/10.1073/pnas.0812294106
  37. White, E. P., Ernest, S. K. M., Kerkhoff, A. J., & Enquist, B. J. (2007). Relationships between body size and abundance in ecology. Trends in Ecology & Evolution, 22(6), 323–330. https://doi.org/10.1016/j.tree.2007.03.007