Decline in holm oak coppices (Quercus ilex L. subsp. ballota (Desf.) Samp.): biometric and physiological interpretations

Abstract

Aim of the study: To analyse the decline in aged holm oak coppice forests as regards above-ground and below-ground fractions and physiological features.Area of study: Centre of the Iberian Peninsula (Guadalajara province). Material and methods: 26 pairs of holm oak stools with different vigour but with similar site and structural characteristics within each pair were selected. Morphological (basal area, number of stools, maximum height) and physiological traits (leaf water potential, stomatal conductance) of the standing stools were assessed. Their aerial and underground parts were extracted and different size fractions of both their above and below-ground biomass were quantified. Linear mixed models were built to test the effect of 'Stool vigour' on the mean behaviour of the measured variables. Additionally, for the aerial part, linear regressions between the weights of the different size fractions and the basal area at breast height were performed using 'Stool vigour' as a fixed factor.Main results: For the same site, root depth, and number and diameter of shoots than good vigour stools, poor vigour stools displayed: lower predawn water potential, greater leaf mass per unit of area; lower total leaf area; lower above-ground biomass (in total as well as per fractions); lower fine roots biomass; lower proportion of leaf biomass and a greater proportion of biomass of both all roots and those with diameter 2-7 cm.Research highlights: The above-ground physiological and morphological characteristics of declined stools are interpreted as poorer adaptation to site conditions. Root system architecture was found to be relevant to explain this behaviour.Additional keywords: decay; stool; above-ground biomass; below-ground biomass; drought; global change.

National scale variability in forest stand variables among regions of provenances in Spain

“…These systems are originated from thinning of closed stands to combine tree, agriculture, and livestock exploitation (Gea-Izquierdo et al 2011;Acácio et al 2017). On the other hand, more closed stands are predominant in other locations of the Iberian Peninsula (Serrada et al 2017). As regards the agrosilvopastoral open woodlands, the stand characteristics reported in this study (large diameter and low regeneration) are in agreement with previous findings at finer scales (Moreno-Fernández et al 2019).…”

“…As regards the vegetative origin, Fagaceae species form both coppices and standards. Hence, some of these species have been managed as coppices to produce firewood over prolonged periods (Cañellas et al 2004;Serrada et al 2017). Furthermore, foreign forest reproductive material or reproductive material from other provenances have sometimes been used in reforestations, especially in the reforestations carried out in the first half of the last century (Ennos et al 1998).…”

Influence of climate and thinning on Quercus pyrenaica Willd. coppices growth dynamics

“…We do not have information on the coppice cycles, i.e., clear-cutting followed by resprouting, in the studied stand. It is reasonable to expect that older stools will have accumulated a large amount of belowground biomass (Salomón et al 2013), which could result in unbalanced structures (Salomón et al 2016;Serrada et al 2017), although Ally et al (2008) rejected this assumption in Populus tremuloides Michx. coppices.…”

“…1 3 charcoal caused harvesting activities to be abandoned and resulted in overstocked and overaged coppices which in turn could lead to increased sensitivity to drought, fires and pests (Rodríguez-Calcerrada et al 2011;De Cáceres et al 2018). Furthermore, repeated coppicing results in large belowground to aboveground biomass ratios, which originates unbalanced structures more prone to perturbations, such as drought (Salomón et al 2016;Serrada et al 2017). In fact, forest managers have attempted to shift from coppices to standards with continuous cover (or coppice-with-standards) through thinning (Salomón et al 2013;Marchi et al 2016).…”

Above and belowground carbon stock of pine plantations and native oak forests coexisting in central Spain

“…According to IGN (2006) and following Soil Taxonomy (Soil Survey Staff, 2003), Haploxeralfs and Xerorthents are the main soils found in the area (Table 1). The aboveground biomass of Quercus and Pinus forests are roughly the same age, with Pinus stands being planted mainly in the 50's and 60's, and the management of the Quercus coppice ceasing in the 60's (Maestre and Cortina 2004;Mauri et al 2016;Serrada et al 2017;Vadell Guiral et al 2019). In the last decades, both forest types have barely seen any management, except for thinning in some Pinus plantations and pruning in one of the Quercus plots.…”