Ectomycorrhizal colonization and growth of the hybrid larch F 1 under elevated CO 2 and O 3

Abstract

We studied the colonization of ectomycorrhizal fungi and species abundance of a hybrid larch (F1) under elevated CO₂ and O₃. Two-year-old seedlings were planted in an Open-Top-Chamber system with treatments: Control (O3 < 6 nmol/mol), O₃ (60 nmol/mol), CO₂ (600 μmol/mol), and CO2 + O₃. After two growing seasons, ectomycorrhiza (ECM) colonization and root biomass increased under elevated CO₂. Additionally, O₃ impaired ECM colonization and species richness, and reduced stem biomass. However, there was no clear inhibition of photosynthetic capacity by O₃. Concentrations of Al, Fe, Mo, and P in needles were reduced by O₃, while K and Mg in the roots increased. This might explain the distinct change in ECM colonization rate and diversity. No effects of combined fumigation were observed in any parameters except the P concentration in needles. The tolerance of F1 to O₃ might potentially be related to a shift in ECM community structure.

Foliar chemical composition of two oak species grown in a free-air enrichment system with elevated O₃ and CO₂

“…These trends have suggested that Qs may have higher ability for the recover from O 3 damages and may be more tolerant to eO 3 than Qm under eCO 2 based on the summary made by Kohno et al (2005) and Yamaguchi et al (2011). No significant effects were observed in foliar P concentration at eO 3 for both species at the present study, which was in agreement with the results of Wang et al (2015). Although we hypothesized that leaf P would be increased under eCO 2 since the acquisition of P is strongly affected by physiological condition of host plants through the morphological and the physiological properties of rhizosphere (Adalsteinsson et al, 1994;Ruiz et al, 1996;Kayama et al, 2005;Kayama and Yamanaka, 2014;Wang et al, 2015), there was no difference in leaf P at eCO 2 .…”

“…No significant effects were observed in foliar P concentration at eO 3 for both species at the present study, which was in agreement with the results of Wang et al (2015). Although we hypothesized that leaf P would be increased under eCO 2 since the acquisition of P is strongly affected by physiological condition of host plants through the morphological and the physiological properties of rhizosphere (Adalsteinsson et al, 1994;Ruiz et al, 1996;Kayama et al, 2005;Kayama and Yamanaka, 2014;Wang et al, 2015), there was no difference in leaf P at eCO 2 . This was also supported by Conroy (1992), indicating the view that eCO 2 increased the P demand of leaves.…”

“…Despite the fact that some previous researches indicated eO 3 and eCO 2 treatment decreased foliar K in potato and beech (e.g. Fangmeier et al, 2002;Thomas et al, 2006), what we found in this study ( Table 2) is in consistence with Wang et al (2015) where leaf K was not clearly different at eO 3 and eCO 2 from that grown under ambient. It was possibly because the decreased photosynthetic rate (Kitao et al, 2015) was somehow offset by the enhanced phytohormones induced by eO 3 or eCO 2 (Yong et al, 2000;Winwood et al, 2007;Matyssek et al, 2012), thereby regulating the foliar K independent with the specific gas treatments.…”

Current and future ozone risks to global terrestrial biodiversity and ecosystem processes

“…Reduced C allocation to roots impairs mycorrhizal symbiosis, for instance, in birch (Kasurinen et al., 2005), hybrid aspen (Edwards & Zak, 2011), beech (Pritsch et al., 2009), hybrid larch (Wang et al., 2015), and blue wild rye ( Elymus glaucus ; Yoshida, Gamon, & Andersen, 2001). Mycorrhizae are ubiquitous in all terrestrial ecosystems and play an essential role in soil–plant nutrient exchange and via the turnover of external mycelium for the transfer of root‐derived C to SOM (Godbold et al., 2006).…”

Effects of CO₂ and O₃ on the interaction between root of woody plants and ectomycorrhizae

“…Moreover, the carbon (C) gain and allocation below ground are also increased. As an indirect result of these changes, the relationship of tree roots and symbionts is altered (Wang et al 2015b).…”