Impact assessment of high soil CO₂on plant growth and soil environment: a greenhouse study

Abstract

To ensure the safety of carbon capture and storage (CCS) technology, insight into the potential impacts of CO2 leakage on the ecosystem is necessary. We conducted a greenhouse experiment to investigate the effects of high soil CO2 on plant growth and the soil environment. Treatments comprised 99.99% CO2 injection (CG), 99.99% N2injection (NG), and no injection (BG). NG treatment was employed to differentiate the effects of O2 depletion from those of CO2 enrichment. Soil CO2 and O2 concentrations were maintained at an average of 53% and 11%, respectively, under CG treatment. We verified that high soil CO2 had negative effects on root water absorption, chlorophyll, starch content and total biomass. Soil microbial acid phosphatase activity was affected by CG treatment. These negative effects were attributed to high soil CO2 instead of low O2 or low pH. Our results indicate that high soil CO2 affected the root system, which in turn triggered further changes in aboveground plant tissues and rhizospheric soil water conditions. A conceptual diagram of CO2 toxicity to plants and soil is suggested to act as a useful guideline for impact assessment of CCS technology.

Effects of Elevated Root-Zone CO2 on Root Morphology and Nitrogen Metabolism Revealed by Physiological and Transcriptome Analysis in Oriental Melon Seedling Roots

“…The root system could protect itself by synthesizing substances such as phenylpropane and glutathione, and by regulating its metabolism through the transmission of hormone signals. As previously reported, when plant roots suffered CO 2 stress, the roots produced abscisic acid and sent a hormone signal to the leaves to close stomata and prevent water loss [8].…”

“…The actual CO 2 concentration in the soil also depends on the soil water content, soil type, soil depth, microbial biomass, and the activities of soil microorganisms. Responses to high CO 2 soil environment have received increased attention recently in several crop species [5][6][7][8]. However, little information is available regarding the molecular mechanisms of plants in response to elevated root-zone CO 2 conditions, especially at the transcriptome level.…”

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

“…The greenhouse experiment was conducted at the campus of Kyung Hee University, South Korea (37°14′24″ N, 127°5′2″ E) ( He et al, 2019b ). The soils used in this experiment were a 1:1 (v/v) mixture of potting and mineral soils.…”

“…During the experimental period, the ambient temperature was 19 ± 3 °C during the day and 6 ± 3 °C at night. The greenhouse remained open and two fans were used to prevent ambient CO 2 accumulation which might affect the plant leaf level CO 2 concentration ( He et al, 2019b ).…”

“…In order to overcome the low sensitivity of these parameters, photosynthetic process-based parameters were tested to determine whether they are more sensitive to CO 2 leakage detection. The photosynthetic rate, stomatal conductance, and transpiration rate were reported to decrease within 1–4 days in soil with high CO 2 (>40%) conditions ( Lake et al, 2016b ; Zhang et al, 2016 ; He et al, 2019b ). Consequently, they are potential early indicators for detecting CO 2 leakage.…”