Comparisons of δ13C values in leaves of aquatic macrophytes from different habitats in Britain and Finland; some implications for photosynthetic processes in aquatic plants
Comparisons of δ13C values in leaves of aquatic macrophytes from different habitats in Britain and Finland; some implications for photosynthetic processes in aquatic plants
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DOI：
10.1007/bf00378804
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发表时间：
1981-08
期刊：
影响因子：
2.7
通讯作者：
C. Osmond;N. Valaane;S. Haslam;P. Uotila;Z. Roksandic
中科院分区：
文献类型：
--
作者：
C. Osmond;N. Valaane;S. Haslam;P. Uotila;Z. Roksandic
测定了不同生境下沉水植物的δ 13 C值，以及二型水生植物挺水、漂浮和沉水叶片的δ 13 C值。在许多情况下，水中溶解的无机碳的δ 13 C值也被测量。在碳酸盐δ 13 C值为-16至-21 ‰的快速流动沃茨中，发现植物δ 13 C值在-40至-50 ‰附近，这与诸如Fontinalis antipyretica等物种几乎完全通过RuP 2羧化酶同化游离CO2的观点一致。在碳酸盐δ 13 C值约为-5 ‰的滞流水中，植物δ 13 C值在-10 ‰ ~-15 ‰之间，这与边界层扩散和/或HCO 3吸收可能决定沉水植物δ 13 C值的观点一致。在碳酸盐δ 13 C值相似但流速不同的沃茨中生长的相同或相关物种的δ 13 C值的比较证实了这一观点;更负的δ 13 C值通常与快速流动水中的植物有关。在英国，而不是在芬兰，二型植物的沉水叶的δ 13 C值几乎总是比气生叶更负。白垩流和酸泉中碳酸盐的δ 13 C值表明呼吸CO2的大量输入，而不是大气中的碳。本文还讨论了碳源δ 13 C的这些变化和扩散过程中同位素分馏对二型植物沉水部分δ 13 C值的贡献。
The δ13C values of submerged aquatic plants from contrasting but relatively defined habitats, and the δ13C values of emergent, floating and submerged leaves of dimorphic aquatic plants, were measured. In many instances the δ13C values of dissolved inorganic carbon in the water were also measured. Plant δ13C values in the vicinity of-40 to-50‰ were found in rapidly flowing spring waters with carbonate δ13C values of-16 to-21‰, consistent with the notion that species such asFontinalis antipyreticaalmost exclusively assimilate free CO2via RuP2carboxylase. Plant δ13C values in the vicinity of-10 to-15‰ in sluggish water with carbonate δ13C values of about-5‰ were observed, consistent with the notion that boundary layer diffusion and/or HCO3-uptake may determine the δ13C value of submerged aquatic plants in these circumstances. Comparisons of δ13C values of the same or related species growing in waters of similar carbonate δ13C value but different flow rates confirmed this view; more negative δ13C values were frequently associated with plants in fast moving water. In Britain, but not in Finland, the δ13C values of submerged leaves of dimorphic plants were almost invariably more negative than in aerial leaves. The δ13C value of carbonate from chalk streams and in acid springs indicate substantial inputs of respiratory CO2, as opposed to atmospheric carbon. The contributions of these variations in δ13C of the carbon source, and of isotope fractionation in diffusion, to the δ13C value of submerged parts of dimorphic plants is discussed.