Resilience of Fungal Communities to Elevated CO2

Abstract

Soil filamentous fungi play a prominent role in regulating ecosystem functioning in terrestrial ecosystems. This necessitates understanding their responses to climate change drivers in order to predict how nutrient cycling and ecosystem services will be influenced in the future. Here, we provide a quantitative synthesis of ten studies on soil fungal community responses to elevated CO2. Many of these studies reported contradictory diversity responses. We identify the duration of the study as an influential parameter that determines the outcome of experimentation. Our analysis reconciles the existing globally distributed experiments on fungal community responses to elevated CO2 and provides a framework for comparing results of future CO2 enrichment studies.

Arbuscular Mycorrhizal Symbiosis as a Promising Resource for Improving Berry Quality in Grapevines Under Changing Environments

“…Elevated CO 2 can promote mycorrhizal colonization of plant roots as a consequence of the enhanced carbon allocation to roots ( Zhu et al, 2016 ; Asha et al, 2017 ), which may result in an increased mineral uptake from soil but not necessarily correlated with nutrient transfer to the host plant ( Smith and Read, 2008 ). Regarding the community composition of AMF, elevated CO 2 increased the ratio of Glomeraceae to Gigasporaceae but this effect may be masked by the natural changes through time ( Cotton et al, 2015 ) and also by the dependency of different fungi on water availability and precipitation ( Veresoglou et al, 2016 ). The application of molecular tools revealed that, at present, Glomeraceae dominate the composition of the AMF communities in vineyards in Oregon (United States) ( Schreiner and Mihara, 2009 ), Piedmont (Italy) ( Balestrini et al, 2010 ) and Burgundy (France) ( Bouffaud et al, 2016 ), being the AMF diversity relatively low, which contrasts with the high diversity of AMF in the rhizosphere of European wild grapevine V. vinifera L. ssp.…”

Impacts of long‐term elevated atmospheric CO2 concentrations on communities of arbuscular mycorrhizal fungi

“…Average AM fungal richness was higher under eCO 2 compared with aCO 2 treatments (though both treatments had equivalent total taxon pools of 51 OTUs). Previously observed increases in total fungal diversity under eCO 2 are determined by the length of the experiment (Veresoglou et al, 2016). Longer-term studies allow greater recruitment from the meta-community of taxa pre-adapted to these new environmental conditions and if sufficiently long term, the evolution of new species (Johnson et al, 2013;Veresoglou et al, 2016), both of which increase local taxa richness.…”

“…Previously observed increases in total fungal diversity under eCO 2 are determined by the length of the experiment (Veresoglou et al, 2016). Longer-term studies allow greater recruitment from the meta-community of taxa pre-adapted to these new environmental conditions and if sufficiently long term, the evolution of new species (Johnson et al, 2013;Veresoglou et al, 2016), both of which increase local taxa richness. At the GiFACE, the expansive semi-natural grassland surrounding eCO 2 FACE rings and the longterm experimental duration certainly provide ample opportunity for recruitment of pre-adaptive AM fungal taxa from the meta-community.…”

“…However, despite significant increases in specific AM fungal taxa in agricultural soy monoculture grown under eCO 2 , changes in community evenness were not observed and were probably suppressed by crop rotational practices (Cotton et al, 2015). This is not necessarily unexpected, as inconsistent responses of fungal diversity, including in a few cases AM fungi, to eCO 2 are also reported across the only ten studies to examine this (Veresoglou et al, 2016); for recent review, see Cotton (2018). However, in these studies AM fungal responses to eCO 2 were tested at the community level, ignoring the subtler population-level dynamics throughout the plant growth period that may be affected by eCO 2 .…”

“…Higher levels of fungal root colonization alongside the presence of arbuscules indicate active symbiosis and physiological compatibility between symbionts, and thus, increases in plant carbon supply to the AM fungi can trigger increased reciprocation in phosphorus and nitrogen to the plant, strengthening and stabilizing the mutualism (Fellbaum et al, 2012(Fellbaum et al, , 2014. However, how these eCO 2 effects translate into changes in the diversity and composition of AM fungal communities in natural ecosystems is unclear (Veresoglou, Anderson, de Sousa, Hempel, & Rillig, 2016).…”