Response of Fagus sylvatica and Picea abies to the interactive effect of neighbor identity and enhanced CO2 levels

Abstract

Enhanced levels of CO 2 affected both the nutrition and morphology of both species. The effect of interspecific competition was dependent on the species identity but not on the CO 2 level. AbstractThe interest in adaptive forest strategies to overcome predicted scenarios of climate change is increasing worldwide. An example of these strategies is the introduction of native species into mono-specific plantations. However, to fully consider this option/strategy, a higher understanding of the responses of forest tree species to concurrent biotic and abiotic factors is needed. The aim of the present study was to assess nutritional and morphological adjustments of individuals of European beech (Fagus sylvatica L.) and Norway Spruce (Picea abies (L.) Karst) growing at enhanced levels of CO 2 and with different proportions of con-specific individuals in its vicinity.Individuals that grew at elevated CO 2 levels showed higher values of relative growth rate (RGR), total twig dry biomass and root biomass, and lower values of leaf area ratio, leaf N and Mg concentrations and soil nutrient concentrations. Individuals of Norway spruce growing in the vicinity of high proportions of European beech showed a reduction in the allocation of biomass to foliar tissue and lower values of RGR and root biomass. European beech, by contrast, showed a limited response to Norway spruce presence and higher capacity in the exploitation of space both above-and belowground. In conclusion, the lower response of European beech to both environmental factors suggests that the introduction of European beech into Norway spruce stands could be a feasible option in current forest transition strategies.

Do adult trees increase conspecific juvenile resilience to recurrent droughts? Implications for forest regeneration

“…, Rolo et al. ). Similarly, facilitated saplings would show a more resource‐acquisitive strategy than those growing in open areas (García‐Cervigón et al.…”

“…Contrary to our expectations, nonetheless, the rest of leaf and shoot traits did not differ between microhabitats. Acclimation of plants to shade involves lower LMA, and greater LAR and LMF to optimize light harvesting (Lambers et al 2008, Rolo et al 2015. Similarly, facilitated saplings would show a more resource-acquisitive strategy than those growing in open areas (Garc ıa-Cervig on et al 2015).…”

“…We avoided branches located under other branches to prevent any confounding effects due to shade (Rolo et al. ). From each branch, the current‐year shoot segment (i.e., year 2016) was cut and needles were removed, scanned (ScanJet 300 HP, Palo Alto, California, USA), and the projected area was measured with ImageJ.…”

“…In all selected saplings, two branches oriented to the south and north from the upper third of the sapling canopy were cut and the number of needle cohorts was counted. We avoided branches located under other branches to prevent any confounding effects due to shade (Rolo et al 2015).…”

Nonstructural carbohydrate-balance response to long-term elevated CO2 exposure in European beech and Norway spruce mixed cultures: biochemical and ultrastructural responses

“…Most importantly, the majority of the studies neither distinguish between individual sugar levels nor even between soluble carbohydrates and starch (e.g. Bader et al 2010;Rolo et al 2015).…”