Changes in soil N2O and CH4 emissions and related microbial functional groups in an artificial CO2 gassing experiment

Evaluation of effective quantum yields of photosystem II for CO2 leakage monitoring in carbon capture and storage sites

“…3 and 4 ), respectively, the Pn, Gs, Tr, and Y(II) were 2–5 days earlier. Our results are consistent with those of Lake et al (2016b) and Zhang et al (2016) , who reported that the effects of elevated soil CO 2 concentration on Pn, Gs, and Tr appeared within 4 days, which was earlier than that in chlorophyl content, observed within 7–15 days ( Lakkaraju et al, 2010 ; Smith et al, 2017 ; He et al, 2019a , 2019b ). As our experiment was the first to test the possibility of using fluorescence parameters to detect CO 2 leakage, there is no reference with which to compare our results.…”

“…5 ; Table 5 ). The recovery of Pn, Gs, and Tr in 10% CO 2 treatment from day 5 might be related to the plant compensation effects to the stress ( Lake et al, 2016b ; He et al, 2019a , 2019b ). However, the overall lower values in the CO 2 treatments than control indicated that CO 2 leakage had adverse effects on the overall photosynthetic processes, which was consistent with the observations of Zhang et al (2016) .…”

“…The indicator evaluation score (IES) was developed to compare the efficiencies of the parameters for CO 2 leakage monitoring. Based on extensive reviews, we set up four criteria for IES, including early detection, CO 2 specificity, field applicability, and cost ( Male et al, 2010 ; Patil, 2012 ; Al-Traboulsi et al, 2012 ; Noble et al, 2012 ; He et al, 2019a ). The scores in each criterion, ranging from 1 to 5, were allocated for each parameter based on the evaluation standards in Table 3 .…”

“…The third criterion of field applicability was identified by examining whether the parameter meets the four sub-standards, which are nondestructive, remotely detectable, automatic, and continuous measurements ( Table 3 ). The selection of sub-standards of field applicability for each parameter was based on the literature and product catalogs ( He et al, 2019a , 2019b ; Li et al, 2013 ; Male et al, 2010 ; ; ). The nondestructive sampling of plants allows sustainable monitoring of CO 2 leakage from plants ( Noble et al, 2012 ).…”

“…Among those CO 2 -affected plant parameters, chlorophyl content was suggested to be a more appropriate parameter than biomass because it can be measured using nondestructive methods such as spectral sensors. However, the change in chlorophyl content due to elevated soil CO 2 is generally observed 7–15 days after the initiation of CO 2 leakage ( Patil, 2012 ; Zhang et al, 2016 ; He et al, 2019a ), showing that it is not an early indicator. Moreover, chlorophyl content change could not differentiate CO 2 stress from other environmental stresses in the field ( Sharma et al, 2014 ).…”