Climate controls act at different scales on the seasonal pattern of Quercus ilex L. stem radial increments in NE Spain

Abstract

Long-term data on radial increment dynamics in Mediterranean species may identify which climatic variables are the main constraints for radial growth and at which temporal scales they act. To this end, we examined stem radial fluctuations in Quercus ilex L., the dominant evergreen oak species in the Western Mediterranean Basin, over a period of 11 years (1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004) at a coastal site in north-eastern Spain. We used manual band dendrometers to record girth changes in trees on north-and south-facing slopes. Annual increments measured by dendrometers showed good agreement with annual tree-ring width. North-facing trees showed a lower long-term cumulative radial increment than south-facing trees. The seasonal radial increment pattern of Q. ilex was bimodal, being characterized by a greater increase in May and a lesser, more variable increase peak in September. Both phases corresponded to warm and moist climatic conditions, whereas radial increase of stems stopped in winter and occasionally in summer. Considering the whole year, mean maximum air temperature was the main factor positively affecting radial increment of Q. ilex from short-(5 days) to-long (30 days) time scales, whereas the accumulated precipitation exerted a similar effect at longer (30 days) scales, but only on south-facing trees. In summer, all trees were positively correlated with precipitation at long-time scales (30 days); however, only stem increment of southfacing trees showed a significant relation to the temperature at short-time scales (10 days). We confirmed the dominant role of temperature as the major constraint on radial increment at short time scales, despite most previous studies were mostly biased towards precipitation effects at monthly scales.

Prior height, growth, and wood anatomy differently predispose to drought-induced dieback in two Mediterranean oak speciesk

“…However, the Portuguese oak shows an earlier phenological development (most primary and secondary growth occur in spring) than holm oak which is able to grow during summer (MontserratMartí et al 2009;Albuixech et al 2012). This is also reflected in the radial growth responses to climate, since tree ring width usually increases in response to wet spring or summer conditions in the case of Portuguese and holm oaks, respectively (Corcuera et al 2004a(Corcuera et al , 2004bGutiérrez et al 2011). From an ecophysiological point of view, the holm oak is a droughttolerant species displaying a tight stomatal control over transpiration, while Mediterranean oak species similar to Portuguese oak show a higher conductance but also experience xylem embolism due to summer drought and freezethaw events in winter (Tognetti et al 1998).…”

Diverse responses of forest growth to drought time‐scales in theNorthernHemisphere

“…Thus, diverse growth responses to droughts of different duration and intensity are expected from regional to local scales depending on the climatic conditions of each site and the responsiveness of each tree species (Gutiérrez et al, 2011;Pasho et al, 2011).…”

Seasonal and daily cycles of stem radial variation of Pinus pinaster in a drought-prone environment

“…Gutierrez et al (2011) reported that Quercus ilex L. radial increment was mainly constrained by temperature, whereas Camarero et al (2010) observed that in Juniperus thurifera L. and Pinus halepensis (Miller) the climatic response changed during the year, with stem radius variations dependent on temperature during growth onset and on precipitation during the summer. A different study revealed that Abies pinsapo (Boiss.)…”