Quercus ilex L. dieback is genetically determined: Evidence provided by dendrochronology, δ13C and SSR genotyping

Francesca Alderotti; Fabiano Sillo; Lorenzo Brilli; Filippo Bussotti; Mauro Centritto; Francesco Ferrini; Antonella Gori; Roberto Inghes; Dalila Pasquini; Martina Pollastrini; Matthias Saurer; Paolo Cherubini; Raffaella Balestrini; Cecilia Brunetti

doi:10.1016/j.scitotenv.2023.166809

Quercus ilex L. dieback is genetically determined: Evidence provided by dendrochronology, δ¹³C and SSR genotyping

Sci Total Environ. 2023 Dec 15:904:166809. doi: 10.1016/j.scitotenv.2023.166809. Epub 2023 Sep 9.

Affiliations

¹ University of Florence, Department of Agriculture, Food, Environment and Forestry, Viale delle idee 30, 50019 Sesto Fiorentino, Piazzale delle Cascine 28, 50144 Florence, Italy; National Research Council of Italy (CNR), Institute for Sustainable Plant Protection, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy; Strada delle Cacce 73, 10135, Torino, Italy.
² National Research Council of Italy (CNR), Institute for Sustainable Plant Protection, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy; Strada delle Cacce 73, 10135, Torino, Italy.
³ CNR-IBE, National Research Council of Italy (CNR), Institute for the BioEconomy, Via Caproni 8, 50145 Firenze, Italy.
⁴ University of Florence, Department of Agriculture, Food, Environment and Forestry, Viale delle idee 30, 50019 Sesto Fiorentino, Piazzale delle Cascine 28, 50144 Florence, Italy.
⁵ University of Florence, Department of Agriculture, Food, Environment and Forestry, Viale delle idee 30, 50019 Sesto Fiorentino, Piazzale delle Cascine 28, 50144 Florence, Italy; National Research Council of Italy (CNR), Institute for Sustainable Plant Protection, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy; Strada delle Cacce 73, 10135, Torino, Italy; National Biodiversity Future Center (www.nfbc.it), Italy.
⁶ University of Florence, Department of Agriculture, Food, Environment and Forestry, Viale delle idee 30, 50019 Sesto Fiorentino, Piazzale delle Cascine 28, 50144 Florence, Italy; National Biodiversity Future Center (www.nfbc.it), Italy.
⁷ WSL Swiss Federal Institute for Forest, Snow and Landscape Research, Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland.
⁸ WSL Swiss Federal Institute for Forest, Snow and Landscape Research, Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland; University of British Columbia, Department of Forest and Conservation Sciences, Vancouver, BC, Canada.
⁹ University of Florence, Department of Agriculture, Food, Environment and Forestry, Viale delle idee 30, 50019 Sesto Fiorentino, Piazzale delle Cascine 28, 50144 Florence, Italy; National Research Council of Italy (CNR), Institute for Sustainable Plant Protection, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy; Strada delle Cacce 73, 10135, Torino, Italy. Electronic address: cecilia.brunetti@ipsp.cnr.it.

PMID: 37690750
DOI: 10.1016/j.scitotenv.2023.166809

Abstract

Quercus ilex L. dieback has been reported in several Mediterranean forests, revealing different degree of crown damages even in close sites, as observed in two Q. ilex forest stands in southern Tuscany (IT). In this work, we applied a novel approach combining dendrochronological, tree-ring δ¹³C and genetic analysis to test the hypothesis that different damage levels observed in a declining (D) and non-declining (ND) Q. ilex stands are connected to population features linked to distinct response to drought. Furthermore, we investigated the impact of two major drought events (2012 and 2017), that occurred in the last fifteen years in central Italy, on Q. ilex growth and intrinsic water use efficiency (WUE_i). Overall, Q. ilex showed slightly different ring-width patterns between the two stands, suggesting a lower responsiveness to seasonal climatic variations for trees at D stand, while Q. ilex at ND stand showed changes in the relationship between climatic parameters and growth across time. The strong divergence in δ¹³C signals between the two stands suggested a more conservative use of water for Q. ilex at ND compared to D stand that may be genetically driven. Q. ilex at ND resulted more resilient to drought compared to trees at D, probably thanks to its safer water strategy. Genotyping analysis based on simple-sequence repeat (SSR) markers revealed the presence of different Q. ilex populations at D and ND stands. Our study shows intraspecific variations in drought response among trees grown in close. In addition, it highlights the potential of combining tree-ring δ¹³C data with SSR genotyping for the selection of seed-bearing genotypes aimed to preserve Mediterranean holm oak ecosystem and improve its forest management.

Keywords: Dendrochronology; Dieback; Drought stress; Mediterranean forest; Quercus ilex; SSR genotyping; Tree-ring δ(13)C; Water strategy.

MeSH terms

Droughts
Ecosystem
Forests
Genotype
Quercus* / physiology
Trees
Water

Substances

Water