Increased wood biomass growth is associated with lower wood density in Quercus petraea (Matt.) Liebl. saplings growing under elevated CO2

Abstract

Atmospheric carbon dioxide (CO2) has increased substantially since the industrial revolution began, and physiological responses to elevated atmospheric CO2 concentrations reportedly alter the biometry and wood structure of trees. Additionally, soil nutrient availability may play an important role in regulating these responses. Therefore, in this study, we grew 288 two-year-old saplings of sessile oak (Quercus petraea (Matt.) Liebl.) in lamellar glass domes for three years to evaluate the effects of CO2 concentrations and nutrient supply on above- and belowground biomass, wood density, and wood structure. Elevated CO2 increased above- and belowground biomass by 44.3% and 46.9%, respectively. However, under elevated CO2 treatment, sapling wood density was markedly lower (approximately 1.7%), and notably wider growth rings—and larger, more efficient conduits leading to increased hydraulic conductance—were observed. Moreover, despite the vessels being larger in saplings under elevated CO2, the vessels were significantly fewer (p = 0.023). No direct effects of nutrient supply were observed on biomass growth, wood density, or wood structure, except for a notable decrease in specific leaf area. These results suggest that, although fewer and larger conduits may render the xylem more vulnerable to embolism formation under drought conditions, the high growth rate in sessile oak saplings under elevated CO2 is supported by an efficient vascular system and may increase biomass production in this tree species. Nevertheless, the decreased mechanical strength, indicated by low density and xylem vulnerability to drought, may lead to earlier mortality, offsetting the positive effects of elevated CO2 levels in the future.

Effect of Elevated CO2 and Drought on Biomass, Gas Exchange and Wood Structure of Eucalyptus grandis

“…This morphological response was supported by an enhanced hydraulic system developed under higher CO 2 levels. Arsić et al [ 52 ] found that Quercus petraea responded likewise in terms of wood structure, a modification that was accompanied by a reduction in wood density. Moreover, it was demonstrated that elevated CO 2 may alter the chemical properties of plant cell walls differently, depending on species and CO 2 interactions with other environmental factors [ 53 ]…”

Forest Adaptation to Climate Change: Altitudinal Response and Wood Variation in Natural-Growth Cunninghamia lanceolata in the Context of Climate Change

“…In this research, seven representative wood traits were meticulously selected for comprehensive analysis. The annual ring width, indicative of the wood layer formed during a tree's one-year growth cycle, serves not only as a crucial indicator of growth rate [47] but also mirrors historical climate changes, ecosystem dynamics, and trees' adaptability to environmental shifts [48]. The heartwood ratio, wood density, and water absorption rate are pivotal in assessing wood quality.…”

The bigger the tree the better the seed – effect of Sessile oak tree diameter on acorn size, insect predation, and germination

“…Oak forests have a high capacity to provide numerous benefits for society: they provide high-value timber for industry, biomass for bio-energy production, key habitats for biodiversity, and valued environments for recreation and other cultural services (Löf et al 2016). Recently, the importance of these species has been particularly highlighted in the context of climate change, where it is expected that these species will play a significant role within their natural range and beyond (Bolte et al 2009;Hanewinkel et al 2013;Kohler et al 2020;Arsić et al 2021).…”