
TY  - JOUR
A1  - Rae, Rowena 
A1  - Rae, Rowena 
A1  - Hanelt, Dieter 
A1  - Hanelt, Dieter 
A1  - Hawes, Ian 
A1  - Hawes, Ian 
T1  - Sensitivity of freshwater macrophytes to UV radiation: relationship to depth zonation in an oligotrophic New Zealand lake
JF  - Marine and Freshwater Research
JO  - Mar. Freshwater Res.
Y1  - 2001
VL  - 52
IS  - 7
SP  - 1023
EP  - 1032
KW  - variable fluorescence, photoinhibition, UVR-absorbing compounds
UR  - https://doi.org/10.1071/MF01016 
N2  - The ultraviolet radiation (UVR) responses of photosynthesis by two freshwater vascular plants, Potamogeton cheesemanii and Isoetes alpinus, and the characean algae Chara fibrosa and C. corallina in Lake Coleridge, New Zealand, were investigated. Experiments comprised 4&#8211;5 h of exposure to different UV wavelengths followed by 17 h of recovery in low light. Photosynthetic competence was assessed by pulse-amplitude-modulated fluorometry. The four species showed different sensitivities to UVR, which were consistent with their upper depth limits. The shallowest-growing species, P. cheesemanii, was uninhibited by UVR, whereas after 5 h of exposure to UVR, inhibition of 15%, 38% and 48% was measured for I. alpinus, C. fibrosaand C. corallinacollected from 4 m, 6.2 m and 16.5 m, respectively. Not all plants recovered fully from UVR inhibition. Plants from upper and lower depths of their growth range did not generally differ in inhibition sustained or ability to recover photosynthesis. The species with greatest tolerance of UVR also contained the highest concentrations of UVR-absorbing pigments. Freshwater macrophytes have differing abilities to tolerate UVR exposure through repair and/or protection strategies and these may be related to their vertical zonation. 
ER  -

