In constructed wetlands (CWs) with forced aeration and vertical flow, plants can suffer from iron (Fe) deficiency due to Fe immobilization in the gravel substrate as a consequence of the oxic condition. The common reed (Phragmites australis) is the most commonly used plant species in CWs and frequently displays Fe-deficiency symptoms particularly in new-established systems. The aim of this study was therefore to study the Fe-nutrition of P. australis in order to gain knowledge on how Fe-deficiency in P. australis can be alleviated. For this purpose, we grew two genetically distinct phylogeographic groups of P. australis hydroponically with seven different Fe concentrations (0, 0.1, 0.2, 0.5, 1.0, 5.0 and 20.0 mg Fe-EDDHA ([iron (3+) ethylenediamine di (o-hydroxyphenylacetic) acid]) L−1) in a phytotron. Both groups responded strongly to the increasing Fe supply. The belowground biomass allocation ratio, light-saturated photosynthesis rates, chlorophyll content and leaf Fe tissue concentration all significantly increased with increasing Fe availability. Phragmites australis in the 0 mg Fe-EDDHA L−1 treatment suffered strongly from Fe deficiency, and plants in the high 20.0 mg Fe-EDDHA L−1 treatment also had reduced growth and Fe toxicity symptoms. The ‘critical deficiency concentration’ of Fe in leaves of juvenile P. australis was 40–50 mg kg−1 DM, and the ‘critical toxicity concentration’ of Fe in leaves of juvenile P. australis were approximately 150 mg kg−1 DM. Overall the two genetically distinct P. australis groups differed in their ecophysiological traits, and the two groups also responded differently to the different Fe-supply rates which may be the result of adaptations obtained in their native growth habitats. We suggest that the Fe-deficiency in CW systems with unsaturated vertical flow and/or forced aeration can be alleviated by application of a foliar spray containing chelated iron. However, the application rate and frequency should be further studied.

Minimum Fe requirement and toxic tissue concentration of Fe in Phragmites australis : A tool for alleviating Fe-deficiency in constructed wetlands / L. Ren, F. Eller, C. Lambertini, W.-. Guo, B.K. Sorrell, H. Brix. - In: ECOLOGICAL ENGINEERING. - ISSN 0925-8574. - 118(2018), pp. 152-160. [10.1016/j.ecoleng.2018.05.009]

Minimum Fe requirement and toxic tissue concentration of Fe in Phragmites australis : A tool for alleviating Fe-deficiency in constructed wetlands

C. Lambertini;
2018

Abstract

In constructed wetlands (CWs) with forced aeration and vertical flow, plants can suffer from iron (Fe) deficiency due to Fe immobilization in the gravel substrate as a consequence of the oxic condition. The common reed (Phragmites australis) is the most commonly used plant species in CWs and frequently displays Fe-deficiency symptoms particularly in new-established systems. The aim of this study was therefore to study the Fe-nutrition of P. australis in order to gain knowledge on how Fe-deficiency in P. australis can be alleviated. For this purpose, we grew two genetically distinct phylogeographic groups of P. australis hydroponically with seven different Fe concentrations (0, 0.1, 0.2, 0.5, 1.0, 5.0 and 20.0 mg Fe-EDDHA ([iron (3+) ethylenediamine di (o-hydroxyphenylacetic) acid]) L−1) in a phytotron. Both groups responded strongly to the increasing Fe supply. The belowground biomass allocation ratio, light-saturated photosynthesis rates, chlorophyll content and leaf Fe tissue concentration all significantly increased with increasing Fe availability. Phragmites australis in the 0 mg Fe-EDDHA L−1 treatment suffered strongly from Fe deficiency, and plants in the high 20.0 mg Fe-EDDHA L−1 treatment also had reduced growth and Fe toxicity symptoms. The ‘critical deficiency concentration’ of Fe in leaves of juvenile P. australis was 40–50 mg kg−1 DM, and the ‘critical toxicity concentration’ of Fe in leaves of juvenile P. australis were approximately 150 mg kg−1 DM. Overall the two genetically distinct P. australis groups differed in their ecophysiological traits, and the two groups also responded differently to the different Fe-supply rates which may be the result of adaptations obtained in their native growth habitats. We suggest that the Fe-deficiency in CW systems with unsaturated vertical flow and/or forced aeration can be alleviated by application of a foliar spray containing chelated iron. However, the application rate and frequency should be further studied.
Chlorosis; Constructed wetland; Critical deficiency concentration; Critical toxicity concentration; Fe-EDDHA; Iron nutrition
Settore BIO/02 - Botanica Sistematica
Settore BIO/03 - Botanica Ambientale e Applicata
Article (author)
File in questo prodotto:
File Dimensione Formato  
1-s2.0-S0925857418301642-main.pdf

accesso riservato

Tipologia: Publisher's version/PDF
Dimensione 1.39 MB
Formato Adobe PDF
1.39 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/903036
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 8
  • ???jsp.display-item.citation.isi??? 8
social impact