Variations of vessel diameter and δ¹³C in false rings of Arbutus unedo L. reflect different environmental conditions

Abstract

Summary• 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 d 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 d 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.

Interpreting the effect of regional climate fluctuations on Quercus robur L. trees under a temperate continental climate (southern Romania)

“…In January, the correlation between annual tree-ring width and temperature (r = -0.34) is opposite to the annual tree-ring-precipitation correlation (r = 0.41). Earlywood indicate difficult conditions during the spring growth (Battipaglia et al, 2010). Oak trees located in warm, low elevation sites may dispose winter and early spring moisture most efficiently, higher temperature in winter might induce an earlier start of the growing season.…”

Morpho-Anatomical Traits for Plant Adaptation to Drought

“…False rings, often referred to as Intra-Annual Density Fluctuations (IADFs) or double rings, are frequent in woods of Mediterranean environments and are triggered by specific patterns of cambial activity. Here, IADFs are caused by the interruption of the normal course of growth due to a sudden drought event, thus determining a zone of wood characterised by an abrupt change in wood anatomical properties (Schulman 1938;Battipaglia et al 2010). Such specific anatomical properties arise in response to drought to enhance safer (i.e.…”

“…less subject to cavitation or embolism), though slower, water transport (we will specify this in the paragraph 2.6). The analysis of the variation of anatomical properties and isotope composition along IADFs, being correlated to stomatal regulation, has proved to be useful to reconstruct phenological events from wood structure, thus unravelling how woody species vary their role of carbon sink in different environmental conditions triggered by climate change or regional modifications of land use (Battipaglia et al 2010). …”

Changes in climate-growth relationships and IADF formation over time of pine species (Pinus halepensis, P. pinaster and P. sylvestris) in Mediterranean environments

“…Despite being at its southern distribution threshold, where a species that usually grows in humid environments could suffer from the effects of increased aridity (Martínez Vilalta & Piñol, 2002), P. sylvestris showed the lowest IADF frequency of the three species on our sample. As pointed out by Battipaglia et al (2010), the frequency and the triggering climatic factors promoting different anatomical characteristics may vary among populations, depending on different environmental conditions.…”