Submersed macrophyte growth at low pH: contrasting responses of three species to dissolved inorganic carbon enrichment and sediment type
Pagano, A.M.; Titus, J.E. (2004). Submersed macrophyte growth at low pH: contrasting responses of three species to dissolved inorganic carbon enrichment and sediment type. Aquat. Bot. 79(1): 65-74. https://dx.doi.org/10.1016/j.aquabot.2004.01.004
In: Aquatic Botany. Elsevier Science: Tokyo; Oxford; New York; London; Amsterdam. ISSN 0304-3770; e-ISSN 1879-1522, more
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Keywords |
Comparative studies Flora > Aquatic organisms > Aquatic plants Growth rate Inorganic matter > Carbon > Inorganic carbon > Dissolved inorganic matter > Dissolved inorganic carbon Properties > Chemical properties > Acidity Properties > Sediment properties Elodea canadensis; Eriocaulon aquaticum; Utricularia vulgaris Fresh water |
Author keywords |
acidic lakes; allocation; aquatic plants; dissolved inorganic carbon;RGR |
Authors | | Top |
- Pagano, A.M.
- Titus, J.E., correspondent
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Abstract |
Responses of three ecologically and morphologically contrasting submersed freshwater macrophyte species to water column dissolved inorganic carbon (DIC) enrichment were determined for plants grown on different sediments. Relative growth rate (RGR) increased significantly (P<0.05, ANOVA) with DIC enrichment for the rooted, highly-branched Elodea Canadensis (0.009 per day and 0.049 per day at 43 and 177 µM DIC, respectively) and for the free-floating Utricularia vulgaris (0.030 per day versus 0.056 per day, respectively), but there was no significant effect of [DIC] on RGR for the isoetid Eriocaulon aquaticum. On the other hand, there was no significant effect of sediment on E. Canadensis or U. vulgaris growth, whereas E. aquaticum grew ca. three-fold faster on the lower fertility sediment with higher porewater [CO2] (P<0.001; 0.019 per day on low fertility sediment versus 0.006 per day on high fertility sediment). No species exhibited a significant [DIC] × sediment interaction for RGR. The root mass fraction of the total plant biomass (R/T) increased significantly for E. canadensis with DIC enrichment (0.03 at low DIC versus 0.17 at high DIC; P<0.001) and with decreasing sediment fertility (0.15 at low fertility versus 0.06 at high fertility; P<0.01). In contrast, E. aquaticum showed an increased R/T value on the more fertile sediment (0.64 at low fertility versus 0.69 at high fertility; P<0.001), particularly at high [DIC] (P<0.05 for the DIC × sediment interaction). The varying responses of different species to water column DIC enrichment may be related to utilization of different carbon pools for photosynthesis, and the growth patterns of E. aquaticum appear to be most closely related to CO2 availability in the sediment. |
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