Age, climate and intra-annual density fluctuations in Pinus halepensis in Spain

Abstract

Intra-annual density fluctuations (IADFs) in tree rings of Aleppo pine (Pinus halepensis) are considered to be among the most promising wood anatomical features in dendrochronological studies. They provide environmental information in addition to those obtained from tree-ring widths. We used a network of 35 sites in Spain, ranging from nearly desert to temperate climate. We analysed tree-ring series of 529 trees to study IADF frequencies, and their dependence on climatic factors and cambial age. The results showed that IADF frequency is age dependent, with its maximum at the cambial age of 27 years (evaluated at breast height). The frequencies varied across the network and at different sites we recorded that 0.3% to 33% of the analysed tree rings contained IADFs. They were more frequent where and when the temperatures were higher, summer drought was intense and autumn was the main precipitation season. IADF formation was particularly related to high minimum temperatures and wet conditions in late summer and autumn. These results suggest that IADF formation is not related to stressful conditions during summer but to favourable conditions during autumn. These conditions promote cambial reactivation and consequently formation of wider tree rings.

Plasticity in Dendroclimatic Response across the Distribution Range of Aleppo Pine (Pinus halepensis)

“…Under other conditions, cambial activity can stop for one to three months during winter, depending on the prevalence of low temperatures [72]. In addition, cambial activity in Pinus halepensis can slow down, or even stop, during summer drought [59], [71], [72], [73], [74] and resume later when moisture availability increases in autumn [59], [71], [73], [74], [75], [76]. In other circumstances, the trees can be subjected to “double stress” characterized by two stops in cambial activity - one during winter, caused by low temperatures, and one during the summer triggered by high temperatures and lack of precipitation [73], [74], [77], [78].…”

The value of crossdating to retain high‐frequency variability, climate signals, and extreme events in environmental proxies

“…False rings are generally caused by a stressful period during the growing season and can be distinguished through crossdating and careful inspection of wood anatomy (Speer, ). Rates vary greatly among species and site, and in extreme cases, false rings can occur in as many as a third (Copenheaver et al ., ; Palakit et al ., ; Novak et al ., , ) to 80% of all increments (Marchand & Filion, ; Battipaglia et al ., ). Without crossdating, locally absent rings and false rings would contribute to the overall error rate, although additional error would almost certainly occur.…”

Climate control on ring width and intra-annual density fluctuations in Pinus kesiya growing in a sub-tropical forest of Manipur, Northeast India

“…However, deviations from such features occur largely due to changes in growing conditions; with the formation of latewood like cells in earlywood part and conversely larger and thinner walled in latewood part due to alteration in climatic conditions becoming unfavourable (favourable) during early (late) growing seasons, respectively. The IADFs in trees growing in different geographic regions have been investigated by various authors to understand climatic information on intra-annual resolution (Priya and Bhat 1998;Bräuning 1999;Campelo et al 2007Campelo et al , 2013Campelo et al , 2015Cherubini et al 2003;Copenheaver et al 2006Copenheaver et al , 2010De Luis et al 2007De Micco et al 2007Edmondson 2010;Gonda-King et al 2012;Masiokas and Villalba 2004;Nabais et al 2014;Novak et al 2013;Olano et al 2015;Olivar et al 2012;Palakit et al 2012;Ren et al 2015;Rozas et al 2011;Speer et al 2004;Vieira et al 2009;Wimmer et al 2000). However, such studies are largely restricted to the high latitude temperate and Mediterranean regions and focus has not been given yet to monsoon regions where growing season is considerably longer.…”