Species-Specific and Altitude-Induced Variation in Karst Plants’ Use of Soil Dissolved Inorganic Carbon

Root-derived carbon sources supporting photosynthesis have been demonstrated to contribute to plant carbon gain in many laboratory experiments. However, it remains largely unknown whether and to what extent soil dissolved inorganic carbon (DIC) influences leaf photosynthesis in karst habitats charac...

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Main Authors: Sen Rao, Yanyou Wu
Format: Article
Language:English
Published: MDPI AG 2022-10-01
Series:Agronomy
Subjects:
Online Access:https://www.mdpi.com/2073-4395/12/10/2489
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author Sen Rao
Yanyou Wu
author_facet Sen Rao
Yanyou Wu
author_sort Sen Rao
collection DOAJ
description Root-derived carbon sources supporting photosynthesis have been demonstrated to contribute to plant carbon gain in many laboratory experiments. However, it remains largely unknown whether and to what extent soil dissolved inorganic carbon (DIC) influences leaf photosynthesis in karst habitats characterized by alkaline soils with low water content. We explored this relationship by measuring the concentrations and carbon isotope signals (δ<sup>13</sup>C) of soil DIC, as well as the δ<sup>13</sup>C of water-soluble organic matter (δ<sub>WSOM</sub>) in leaves of nine woody species across an altitudinal gradient in karst habitats. The δ<sub>WSOM</sub> varied among species by 7.23‰ and deviated from the δ<sup>13</sup>C of photosynthates solely assimilated from atmospheric CO<sub>2</sub> (δ<sub>A</sub>) by 0.44–5.26‰, with a mean value of 2.20‰. This systematical discrepancy (δ<sub>A</sub> − δ<sub>WSOM</sub>) could only be explained by the contribution of soil DIC to leaf total photosynthesis (<i>f</i><sub>DIC_soil</sub>). The average values of <i>f</i><sub>DIC_soil</sub> considerably varied among the nine species, ranging from 2.48% to 9.99%, and were comparable with or slightly lower than those of previous laboratory experiments. Furthermore, the <i>f</i><sub>DIC_soil</sub> of two species significantly increased with altitude, whereas another species exhibited an opposite pattern, suggesting a highly spatial heterogeneity of DIC utilization. The present study improved our understanding of how plants adapt to the alkaline–drought soil conditions of karst habitats and thus acquire additional carbon for growth.
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spelling doaj.art-4e459ace3444414c86cb84e88084359f2023-11-23T22:28:06ZengMDPI AGAgronomy2073-43952022-10-011210248910.3390/agronomy12102489Species-Specific and Altitude-Induced Variation in Karst Plants’ Use of Soil Dissolved Inorganic CarbonSen Rao0Yanyou Wu1College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, ChinaState Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, ChinaRoot-derived carbon sources supporting photosynthesis have been demonstrated to contribute to plant carbon gain in many laboratory experiments. However, it remains largely unknown whether and to what extent soil dissolved inorganic carbon (DIC) influences leaf photosynthesis in karst habitats characterized by alkaline soils with low water content. We explored this relationship by measuring the concentrations and carbon isotope signals (δ<sup>13</sup>C) of soil DIC, as well as the δ<sup>13</sup>C of water-soluble organic matter (δ<sub>WSOM</sub>) in leaves of nine woody species across an altitudinal gradient in karst habitats. The δ<sub>WSOM</sub> varied among species by 7.23‰ and deviated from the δ<sup>13</sup>C of photosynthates solely assimilated from atmospheric CO<sub>2</sub> (δ<sub>A</sub>) by 0.44–5.26‰, with a mean value of 2.20‰. This systematical discrepancy (δ<sub>A</sub> − δ<sub>WSOM</sub>) could only be explained by the contribution of soil DIC to leaf total photosynthesis (<i>f</i><sub>DIC_soil</sub>). The average values of <i>f</i><sub>DIC_soil</sub> considerably varied among the nine species, ranging from 2.48% to 9.99%, and were comparable with or slightly lower than those of previous laboratory experiments. Furthermore, the <i>f</i><sub>DIC_soil</sub> of two species significantly increased with altitude, whereas another species exhibited an opposite pattern, suggesting a highly spatial heterogeneity of DIC utilization. The present study improved our understanding of how plants adapt to the alkaline–drought soil conditions of karst habitats and thus acquire additional carbon for growth.https://www.mdpi.com/2073-4395/12/10/2489soil dissolved inorganic carbonphotosynthesiswater-soluble organic matterstable isotopecontribution
spellingShingle Sen Rao
Yanyou Wu
Species-Specific and Altitude-Induced Variation in Karst Plants’ Use of Soil Dissolved Inorganic Carbon
Agronomy
soil dissolved inorganic carbon
photosynthesis
water-soluble organic matter
stable isotope
contribution
title Species-Specific and Altitude-Induced Variation in Karst Plants’ Use of Soil Dissolved Inorganic Carbon
title_full Species-Specific and Altitude-Induced Variation in Karst Plants’ Use of Soil Dissolved Inorganic Carbon
title_fullStr Species-Specific and Altitude-Induced Variation in Karst Plants’ Use of Soil Dissolved Inorganic Carbon
title_full_unstemmed Species-Specific and Altitude-Induced Variation in Karst Plants’ Use of Soil Dissolved Inorganic Carbon
title_short Species-Specific and Altitude-Induced Variation in Karst Plants’ Use of Soil Dissolved Inorganic Carbon
title_sort species specific and altitude induced variation in karst plants use of soil dissolved inorganic carbon
topic soil dissolved inorganic carbon
photosynthesis
water-soluble organic matter
stable isotope
contribution
url https://www.mdpi.com/2073-4395/12/10/2489
work_keys_str_mv AT senrao speciesspecificandaltitudeinducedvariationinkarstplantsuseofsoildissolvedinorganiccarbon
AT yanyouwu speciesspecificandaltitudeinducedvariationinkarstplantsuseofsoildissolvedinorganiccarbon