Growth, photosynthesis and acclimation by two submerged macrophytes in relation to temperature

Abstract

In this study we examine the influence of temperature on growth, photosynthetic performance and acclimation of two submerged macrophyte species, Elodea canadensis L.C. Rich and Ranunculus aquatilis (L.) Wimmer. The plants were grown at 5, 10 and 15°C and a photon flux density of 300 μmol m s (PAR) in a medium with an alkalinity of 0.85 meq l bubbled with atmospheric air containing 400 ppm CO. In general, growth rates of both species increased with temperature with a Q varying from 2.3 to 3.5. An exception was Elodea at 5°C, where growth was nearly arrested. Temperature effects on ambient rates of net photosynthesis and photosynthetic capacity followed the pattern observed for growth. Dark respiration was not suppressed for Elodea at 5°C and both species had a Q of 2.3. The light-use efficiency (α) for photosynthesis declined with increasing growth temperature for Ranunculus. For Elodea no difference in α was observed between 10 and 15°C; at 5°C, however, α was reduced by about 30%. Both species acclimated to temperature as shown in a series of experiments in which the plants were exposed to a change in temperature. Acclimation was faster for shoots transferred from low to high temperature, where growth rates stabilised after a few days; for shoots transferred to low temperature growth rates still changed after 22 days. Although acclimation was evident, the changes in the metabolic apparatus were insufficient to balance effects of temperature. It is suggested that temperature may affect local distribution of the two species and their ability to grow in turbid or deep water.

Photosynthetic Characteristics of Marestail Using PAM Fluorometry

“…This is similar to the results of Madsen and Brix (1997) who found that Ranunculus aquatilis had high chlorophyll a concentration at low temperature [1]. However, Santamarí a et al (1998) reported that chlorophyll a concentration increased with increasing temperature in Ruppia drepanensis [2].…”

Effects of warming on Potamogeton crispus growth and tissue stoichiometry in the growing season

“…Macrophytes are key components in the ecological functioning of shallow lake ecosystems and they are affected by warming in various ways (Kosten et al, 2009). At the level of the plant individual, warming may affect plant physiology (Madsen and Brix, 1997;Rooney and Kalff, 2000), growth (Haag and Gorham, 1977;Short and Neckles, 1999) and reproduction (Van Vierssen et al, 1984;Mckee et al, 2002). Furthermore, warming may result in * Corresponding author.…”

The Effect of Riparian Forest Shade on the Structural Characteristics of Macrophytes in a Mid-Forest Lake

“…water density and viscosity, the solubility of solids and gases and the rate of metabolic processes in plants (Chełmicki, 2001; Squires et al, 2002;Sevindik and Celik, 2014). The temperature tolerance range of individual plant species is genetically fixed and most freshwater macrophytes appear to be eurythermic (Madsen and Brix, 1997;Feldmann, 2012).…”