The effects of NH4+ and NO3- on growth, resource allocation and nitrogen uptake kinetics of Phragmites australis and Glyceria maxima
Tylova-Munzarova, E.; Lorenzen, B.; Brix, H.; Votrubova, O. (2005). The effects of NH4+ and NO3- on growth, resource allocation and nitrogen uptake kinetics of Phragmites australis and Glyceria maxima. Aquat. Bot. 81(4): 326-342. https://dx.doi.org/10.1016/j.aquabot.2005.01.006
In: Aquatic Botany. Elsevier Science: Tokyo; Oxford; New York; London; Amsterdam. ISSN 0304-3770; e-ISSN 1879-1522, more
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| Keywords |
Eutrophication
Glyceria; Phragmites Adans. [WoRMS]
Fresh water |
| Author keywords |
Phragmites; Glyceria; eutrophication; wetland plant; nitrate nutrition;ammonium nutrition; nitrogen form; NO3- uptake; NH4+ uptake;Michaelis-Menten kinetic |
| Authors | | Top |
- Tylova-Munzarova, E.
- Lorenzen, B.
- Brix, H.
- Votrubova, O.
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| Abstract |
The effects of NH4+ or NO3- on growth, resource allocation and nitrogen (N) uptake kinetics of two common helophytes Phragmites australis (Cav.) Trin. ex Steudel and Glyceria maxima (Hartm.) Holmb. were studied in semi steady-state hydroponic cultures. At a steady-state nitrogen availability of 34 μM the growth rate of Phragmites was not affected by the N form (mean RGR = 35.4 mg g−1 d−1), whereas the growth rate of Glyceria was 16% higher in NH4+-N cultures than in NO3--N cultures (mean = 66.7 and 57.4 mg g−1 d−1 of NH4+ and NO3- treated plants, respectively). Phragmites and Glyceria had higher S/R ratio in NH4+ cultures than in NO3-− cultures, 123.5 and 129.7%, respectively. Species differed in the nitrogen utilisation. In Glyceria, the relative tissue N content was higher than in Phragmites and was increased in NH4+ treated plants by 16%. The tissue NH4+ concentration (mean = 1.6 μmol g fresh wt−1) was not affected by N treatment, whereas NO3-− contents were higher in NO3- (mean = 1.5 μmol g fresh wt−1) than in NH4+ (mean = 0.4 μmol g fresh wt−1) treated plants. In Phragmites, NH4+ (mean = 1.6 μmol g fresh wt−1) and NO3- (mean = 0.2 μmol g fresh wt−1) contents were not affected by the N regime. Species did not differ in NH4+ (mean = 56.5 μmol g−1 root dry wt h−1) and NO3- (mean = 34.5 μmol g−1 root dry wt h−1) maximum uptake rates (Vmax), and Vmax for NH4+ uptake was not affected by N treatment. The uptake rate of NO3- was low in NH4+ treated plants, and an induction phase for NO3- was observed in NH4+ treated Phragmites but not in Glyceria. Phragmites had low Km (mean = 4.5 μM) and high affinity (10.3 l g−1 root dry wt h−1) for both ions compared to Glyceria (Km = 6.3 μM, affinity = 8.0 l g−1 root dry wt h−1). The results showed different plasticity of Phragmites and Glyceria toward N source. The positive response to NH4+-N source may participates in the observed success of Glyceria at NH4+ rich sites, although other factors have to be considered. Higher plasticity of Phragmites toward low nutrient availability may favour this species at oligotrophic sites. |
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