Tree vigour influences secondary growth but not responsiveness to climatic variability in Holm oak

Land-use practices (coppices and dehesas) and management intensity modulate responses of Holm oak growth to drought

“…Holm oak forms a diffuse-to-semi-ring porous wood with multi-seriate rays (Schweingruber, 1990), making tree-ring boundaries to be difficult to be distinguished for this species. Still, several studies performed in recent times have developed reliable tree-ring chronologies on this species (Campelo et al, 2009;Gea-Izquierdo et al, 2011;Natalini et al, 2016;Heres ¸ et al, 2018).…”

“…Given these conditions and considering that trees' growth under Mediterranean-type climate is strongly limited by water availability (Pasho et al, 2011), it is not surprising that drought-induced tree decline and mortality events have become widespread in such areas within the last decades (Allen et al, 2010;Carnicer et al, 2011;Heres ¸ et al, 2012;Hartmann et al, 2018;Gea-Izquierdo et al, 2019). Even tree species considered to have a marked xylem resistance to drought-induced embolism such as Holm oak (Quercus ilex L.) or Cork oak (Quercus suber L.) (Gil-Pelegrín et al, 2017) have started to show worrisome signs of decline and mortality in different regions across Spain (Carrasco, 2009;Barbeta et al, 2013;Natalini et al, 2016;Heres ¸ et al, 2018). Consequently, there is an urgent need to advance our understanding on the response of trees to drought and the factors that modulate this response in face of more frequent and severe climate change associated droughts (IPCC, 2014).…”

“…Drought-induced decline, usually manifested as foliage loss (Carnicer et al, 2011) and growth reduction (Camarero et al, 2015a,b;Camarero et al, 2018;Heres ¸ et al, 2018), is a consequence of the dysfunction in the hydraulics and carbon allocation of a tree system (Sala et al, 2012). Thus, such relatively short-term external responses of trees to severe drought events (i.e., foliage loss) may be used as possible indicators of internal growth responses (i.e., tree rings) (Heres ¸ et al, 2018). In this sense, annual tree rings provide a retrospective way to quantify growth responses to climate and to evaluate how severe droughts impact tree vigour and modulate the resilience capacity of their growth (Camarero et al, 2015a).…”

Micropropagation, Characterization, and Conservation of Phytophthora cinnamomi-Tolerant Holm Oak Mature Trees

“…Since the 1990s, and particularly in recent years, dehesas have been seriously affected by oak decline disease or "la seca", which jeopardizes the long-term survival of this valuable ecosystem. The etiology of the disease is multiple and usually results from the interaction of several factors [4], such as aging and low natural regeneration of trees [5], the appearance of extreme climate events promoted by climate change including increased temperatures and altered precipitation regimes [6][7][8], and the emergence of new diseases and outbreaks of soil pathogens, mainly Phytophthora cinnamomi Rands (Pc) [9,10]. The incidence of holm oak decline is increasing and affecting more and more areas in the Mediterranean region [11].…”

Radial growth of trees differing in their vitality in the middle-aged Scots pine forests in the Kola peninsula

“…radial growth in Central Europe, while in Northern Europe the tree rings and the temperature correlate positively. Intracoenotic factors connected with intra-and interspecific competition between trees are also important resulting in the differentiation of individuals in terms of growth rate and vitality status (Demidko et al 2010;Das 2012;Hereş et al 2018). Several authors found a significant correlation between stem radial growth and main indicators of vitality status of conifer trees such as crown density (Demidko 2011;Cortini et al 2016;Donnelly et al 2017) and needle mass (Vanninen 2004).…”