title: Variations of vessel diameter and δ13C in false rings of Arbutus unedo L. reflect different environmental conditions.
abstract: Woody species in Mediterranean ecosystems form intra-annual density fluctuations (IADFs) in tree rings in response to changes in environmental conditions, especially water availability. Dendrochronology, quantitative wood anatomy and high-resolution isotopic analysis (using a laser ablation technique) were used to characterize IADFs in Arbutus unedo shrubs grown on two sites with different water availability on the island of Elba (Italy). Our findings show that IADF characterization can provide information about the relationship between environmental factors and tree growth at the seasonal level. At the more xeric site, IADFs mainly located in the early and middle parts of the annual ring, showed a decrease in vessel size and an increase in δ(13) C as a result of drought deficit. Opposite trends were found at the more mesic site, with IADFs located at the end of the ring and associated with a lower δ(13) C. Moreover, at the first site, IADFs are induced by drought deficit, while at the second site IADFs are linked with the regrowth in the last part of the growing season triggered by favourable wet conditions. This combined approach is a promising way for dating problematic wood samples and interpreting the phenomena that trigger the formation of IADFs in the Mediterranean environment.
authors.affiliation: WSL Swiss Federal Institute for Forest, Snow and Landscape Research, CH-8903 Birmensdorf, Switzerland. giovanna.battipaglia@enea.it
authors.forename: Giovanna
authors.initials: G
authors.lastname: Battipaglia
authors.forename: Veronica
authors.initials: V
authors.lastname: De Micco
authors.forename: Willi A
authors.initials: WA
authors.lastname: Brand
authors.forename: Petra
authors.initials: P
authors.lastname: Linke
authors.forename: Giovanna
authors.initials: G
authors.lastname: Aronne
authors.forename: Matthias
authors.initials: M
authors.lastname: Saurer
authors.forename: Paolo
authors.initials: P
authors.lastname: Cherubini
mesh_terms: D002247:Carbon Isotopes; D002482:Cellulose / Q000378:metabolism; D004777:Environment; D029791:Ericaceae / Q000033:anatomy & histology* / Q000254:growth & development*; D007558:Italy; D058526:Plant Vascular Bundle / Q000033:anatomy & histology* / Q000254:growth & development*; D011891:Rain; D012987:Soil / Q000032:analysis; D013696:Temperature; D014934:Wood / Q000033:anatomy & histology
chemical_list: D002247:Carbon Isotopes; D012987:Soil; D002482:Cellulose