Effects of Elevated [CO2] and Low Soil Moisture on the Physiological Responses of Mountain Maple (Acer spicatum L.) Seedlings to Light

Abstract

Global climate change is expected to affect how plants respond to their physical and biological environments. In this study, we examined the effects of elevated CO2 ([CO2]) and low soil moisture on the physiological responses of mountain maple (Acer spicatum L.) seedlings to light availability. The seedlings were grown at ambient (392 µmol mol−1) and elevated (784 µmol mol−1) [CO2], low and high soil moisture (M) regimes, at high light (100%) and low light (30%) in the greenhouse for one growing season. We measured net photosynthesis (A), stomatal conductance (g s), instantaneous water use efficiency (IWUE), maximum rate of carboxylation (V cmax), rate of photosynthetic electron transport (J), triose phosphate utilization (TPU)), leaf respiration (R d), light compensation point (LCP) and mid-day shoot water potential (Ψx). A and g s did not show significant responses to light treatment in seedlings grown at low soil moisture treatment, but the high light significantly decreased the C i/C a in those seedlings. IWUE was significantly higher in the elevated compared with the ambient [CO2], and the effect was greater at high than the low light treatment. LCP did not respond to the soil moisture treatments when seedlings were grown in high light under both [CO2]. The low soil moisture significantly reduced Ψx but had no significant effect on the responses of other physiological traits to light or [CO2]. These results suggest that as the atmospheric [CO2] rises, the physiological performance of mountain maple seedlings in high light environments may be enhanced, particularly when soil moisture conditions are favourable.

The space‐time continuum: the effects of elevated CO2 and temperature on trees and the importance of scaling

“…Norby et al 2003). Here, we pool LCP measurements from 13 studies of R light relative to 25°C 0 y = 0.167e 0.0712x r 2 = 0.92 p < 0.0001 Atkin et al 2000 trees grown at ambient and elevated CO2 conditions, using reported values or values digitized from figures (Grulke et al 1993;Stewart & Hoddinott 1993;Kubiske & Pregitzer 1996;Bartak et al 1999;Lewis et al 1999;Wang et al 2000;Hättenschwiler 2001;Takeuchi et al 2001;Maier et al 2002;Norby et al 2003;Springer & Thomas 2007;Danyagri & Dang 2013;Urban et al 2014).There is evidence that the LCP does indeed decrease in trees grown at elevated CO2 conditions ( Fig. 6): the LCP is 12% lower in elevated CO2-grown foliage than in ambient CO2-grown leaves across the entire dataset (r 2 = 0.83, P < 0.0001).…”

Biomass partitioning in a future dry and CO2 enriched climate: Shading aggravates drought effects in Scots pine but not European black pine seedlings

“…Rising CO 2 concentrations could therefore change the optimal partitioning and hence affect both light usage and water uptake of tree seedlings. Experiments testing the co-limitation of more than two resources are scarce (but see Danyagri & Dang, 2013;Pardos, Puértolas, Aranda, & Pardos, 2006). Growth responses of tree seedlings to simultaneous changes in light × water × CO 2 concentrations are therefore not well understood.…”

High nutrient supply and interspecific belowground competition enhance the relative performance of Picea mariana (Mill). B.S.P seedlings over Picea glauca [Moench] Voss. under elevated CO2

“…Dang-supervisor of Marfo, initiated the research, advised Marfo in the entire process of the research, adapted this manuscript from Marfo's dissertation, re-wrote substantial amount of the text, revised figures, and made some new figures Du: contributed to the development of the manuscript Newaz: re-analyzed some of the results, updated the literature and some part of the introduction and discussions photosynthesis (Dang et al 2020), at least in the short term. However, the responses and interactions may be modified by other environmental factors such as nutrient availability (Danyagri and Dang 2013, Li et al 2013, Li et al 2015, Danyagri and Dang, 2014a, b, c, Newaz et al 2016, Newaz et al 2017, Tedla et al 2020); e.g., low nutrient supply reduces the stimulation of photosynthesis by elevated CO 2 (Zhang et al 2006;Cao et al 2007;Ambebe et al 2010;Danyagri and Dang 2014b).…”