Collective growth patterns reveal the high growing potential of older silver fir trees in a primeval forest in Romania’s Southern Carpathians

  • Sergiu A. HORODNIC University “Ştefan cel Mare”of Suceava, Faculty of Forestry, 13 Universităţii, 720229, Suceava
  • Cătălin C. ROIBU University “Ştefan cel Mare”of Suceava, Faculty of Forestry, 13 Universităţii, 720229, Suceava
Keywords: basal area increment; collective growth patterns; ecological modelling; intraspecific facilitation; old-growth forest


The trees’ ability to respond and adjust to very different growing conditions during their lifespans varies depending on tree species and the site-specific situations. Identifying the underlying mechanisms and the individual drivers that may affect the patterns of tree growth is crucial in ecological and economic terms. How long can forest trees grow and sustain biomass accumulation, with increasing age, is still under debate. In order to determine the factors that influence growth releases for silver fir (Abies alba Mill.) trees in a temperate old-growth forest of Romania's Southern Carpathians, an analysis of radial and basal area growth patterns was initiated. Dendroecological methods were used to reconstruct radial growth both at the individual level, but especially at the group level, in four clusters obtained by a prior k-cluster analysis depending on social status. The study results showed that the growth rate of older trees increases continuously for this species at stand level, even after the typical harvesting age in managed forests. Although the direction and intensity of the climate-growth correlations at individual level were very different, the considered climatic variables explaining little to none of the growth variation, the cumulative response of the analysed trees to climate change is directly correlated with the mean July-August temperature, confirming the capacity of the silver fir to tolerate drought. Our results demonstrate that the trees of the same species are able to obtain together a temporal plasticity in strategies, exceeding the adaptability of individuals considered separately and suggest the positive impact of facilitative intraspecific interactions on forest growth.


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Assmann E (1970). The principles of forest yield study: Studies in the organic production, structure, increment, and yield of forest stands. Pergamon Press, Oxford.

Barker JL, Bronstein JL, Friesen ML, Jones EI, Reeve HK, Zink AG, Frederickson ME (2017). Synthesizing perspectives on the evolution of cooperation within and between species. Evolution 71:814-825.

Biernaskie JM (2011). Evidence for competition and cooperation among climbing plants. Proceedings of the Royal Society B: Biological Sciences 278:1989-1996.

Black BA, Abrams MD (2004). Development and application of boundary-line release criteria. Dendrochronologia 22:31-42.

Bosela M, Lukac M, Castagneri D, Sedmák R, Biber P, Carrer M, … Büntgen U (2018). Contrasting effects of environmental change on the radial growth of co-occurring beech and fir trees across Europe. Science of the Total Environment 615:1460-1469.

Bowman DMJS, Brienen RJW, Gloor E, Phillips OL, Prior LD (2013). Detecting trends in tree growth: Not so simple. Trends in Plant Science 18(1):11-17.

Callaway RM, Mahall BE (2007). Plant ecology: Family roots. Nature 448:145-147.

Carrer M (2011). Individualistic and Time-Varying Tree-Ring Growth to Climate Sensitivity. PLoS One 6(7):1-8.

Castagneri D, Storaunet KO, Rolstad J (2013). Age and growth patterns of old Norway spruce trees in Trillemarka forest, Norway. Scandinavian Journal of Forest Research 28:232-240.

Di Filippo A, Biondi F, Piovesan G, Ziaco E (2017). Tree ring‐based metrics for assessing old‐growth forest naturalness. Journal of Applied Ecology 54:737-749.

Ehlers BK, Damgaard CF, Laroche F (2016). Intraspecific genetic variation and species coexistence in plant communities. Biology Letters 12:20150853.

Gadow KV, Hui G (1999). Modelling Forest Development. Forestry Sciences Series, Kluwer Academic Publishers, Dordrecht.

Gagliano M (2015). In a green frame of mind: perspectives on the behavioural ecology and cognitive nature of plants. AoB Plants 7:plu075.

Gagliano M, Vyazovskiy VV, Borbély AA, Grimonprez M, Depczynski M (2016). Learning by association in plants. Scientific Reports 6: 38427.

Harris I, Jones PD, Osborn TJ, Lister DH (2014). Updated high-resolution grids of monthly climatic observations - the CRU TS3.10 Dataset. International Journal of Climatology 34:623-642.

Heer K, Behringer D, Piermattei A, Bässler C, Brandl R, Fady B, … Opgenoorth L (2018). Linking dendroecology and association genetics in natural populations: stress responses archived in tree rings associate with SNP genotypes in silver fir (Abies alba Mill.). Molecular Ecology 27(6):1428-1438.

Horodnic SA, Roibu CC (2018). A Gaussian multi-component model for the tree diameter distribution in old-growth forests. European Journal of Forest Research 137:185-196.

Kunstler G, Albert CH, Courbaud B, Lavergne S, Thuiller W, Vieilledent G, … Coomes DA (2011). Effects of competition on tree radial-growth vary in importance but not in intensity along climatic gradients. Journal of Ecology 99(1):300-312.

Kunstler G, Falster D, Coomes DA, Hui F, Kooyman RM, Laughlin DC, … Westoby M (2016). Plant functional traits have globally consistent effects on competition. Nature 529(7571):204-207.

Lenton TM (1998). Gaia and natural selection. Nature 394:439-447.

Michaletz ST, Cheng D, Kerkhoff AJ, Enquist BJ (2014). Convergence of terrestrial plant production across global climate gradients. Nature 512:39-43.

Niukkanen L, Kuuluvainen T (2011). Radial growth patterns of dominant trees in two old-growth forests in eastern Fennoscandia. Journal of Forest Research 16(3):228-236.

Nowacki GJ, Abrams MD (1997). Radial-growth averaging criteria for reconstructing disturbance histories from presettlement-origin oaks. Ecological Monographs 67(2):225-249.

Osborn TJ, Barichivich J, Harris I, van der Schrier G, Jones PD (2017). Monitoring global drought using the self-calibrating Palmer Drought Severity Index. State of the Climate in 2016. Bulletin of the American Meteorological Society 98:S32-S33.

Petritan IC, Commarmot B, Hobi ML, Petritan AM, Bigler C, Abrudan IV, Rigling A (2015). Structural patterns of beech and silver fir suggest stability and resilience of the virgin forest Sinca in the Southern Carpathians, Romania. Forest Ecology and Management 356:184-195.

Pretzsch H (2009). Forest Dynamics, Growth, and Yield. In: Forest Dynamics, Growth and Yield: from measurement to model. Springer, Berlin, Heidelberg pp. 1-39.

Rohner B, Waldner P, Lischke H, Ferretti M, Thürig E (2018). Predicting individual-tree growth of central European tree species as a function of site, stand, management, nutrient, and climate effects. European Journal of Forest Research 137:29-44.

Rozas V (2015). Individual-based approach as a useful tool to disentangle the relative importance of tree age, size and inter-tree competition in dendroclimatic studies. iForest 8:187-194.

Ryan MG, Binkley D, Fownes JH (1997). Age-related decline in forest productivity: pattern and process. Advances in Ecological Research 27:213-262.

Sala A, Fouts W, Hoch G (2011). Carbon storage in trees: Does relative carbon supply decrease with tree size? In: Meinzer FC, Lachenbruch B, Dawson TE (Eds). Size‐ and Age‐Related Changes in Tree Structure and Function. Springer, Berlin, Germany pp. 287-306.

Salzer MW, Hughes MK, Bunn AG, Kipfmueller KF (2009). Recent unprecedented tree-ring growth in bristlecone pine at the highest elevations and possible causes. Proceedings of the National Academy of Sciences of the United States of America 106(48):20348-20353.

Schrödinger E (1945). What is Life? Cambridge University Press, New York.

Schuster R, Oberhuber W (2013). Age-dependent climate-growth relationships and regeneration of Picea abies in a drought-prone mixed coniferous forest in the Alps. Canadian Journal of Forest Research 43(7):609-618.

Simard SW (2018). Mycorrhizal Networks Facilitate Tree Communication, Learning, and Memory. In: Baluska F, Gagliano M, Witzany G (Eds.) Memory and Learning in Plants. Signaling and Communication in Plants (pp. 191-213). Springer, Cham.

Sillett SC, Van Pelt R, Koch GW, Ambrose AR, Carroll AL, Antoine ME, Mifsud BM (2010). Increasing wood production through old age in tall trees. Forest Ecology and Management 259(5):976-994.

Stephenson NL, Das AJ, Condit R, Russo SE, Baker PJ, Beckman NG, … Zavala MA (2014). Rate of tree carbon accumulation increases continuously with tree size. Nature 507:90-93.

Trotsiuk V, Svoboda M, Weber P, Pederson N, Klesse S, Janda P, … Frank D (2016). The legacy of disturbance on individual tree and stand-level aboveground biomass accumulation and stocks in primary mountain Picea abies forests. Forest Ecology and Management 373:108-115.

Urrutia‐Jalabert R, Malhi Y, Barichivich J, Lara A, Delgado‐Huertas A, Rodríguez CG, Cuq E (2015). Increased water use efficiency but contrasting tree growth patterns in Fitzroya cupressoides forests of southern Chile during recent decades. Journal of Geophysical Research-Biogeosciences 120:2505-2524.

Vašíčková I, Šamonil P, Fuentes UAE, Král K, Daněk P, Adam D (2016). The true response of Fagus sylvatica L. to disturbances: A basis for the empirical inference of release criteria for temperate forests. Forest Ecology and Management 374:174-185.

Voelker SL (2011). Age-dependent changes in environmental influences on tree growth and their implications for forest responses to climate change. In: Meinzer FC, Lachenbruch B, Dawson TE (Eds). Size- and age-related changes in tree structure and function. Springer, Berlin, Germany pp. 455-479.

Zaiontz C (2015). Real statistics using Excel. Retrieved 2020 June 14 from

How to Cite
HORODNIC, S. A., & ROIBU, C. C. (2020). Collective growth patterns reveal the high growing potential of older silver fir trees in a primeval forest in Romania’s Southern Carpathians. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 48(2), 1085-1099.
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