|A comparison of the morphology, gas space anatomy and potential for internal aeration in Phragmites australis under variable and static water regimes|
White, S.D.; Ganf, G.G. (2002). A comparison of the morphology, gas space anatomy and potential for internal aeration in Phragmites australis under variable and static water regimes. Aquat. Bot. 73(2): 115-127
In: Aquatic Botany. Elsevier Science: Tokyo; Oxford; New York; London; Amsterdam. ISSN 0304-3770, more
Aquatic plants; Convection; Convective flow; Diffusion; Phragmites australis (Cav.) Trin. ex Steud. [WoRMS]
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To examine the effect of water regime on the potential for internal aeration in Phragmites australis, the morphology and gas space anatomy of plants grown in ponds under constant water levels were compared with those of plants growing in the field where water levels varied by 1.24m over the growing season. Pond plants were grown at depths ranging from 5 to 65cm depth whilst the field survey examined plants growing at instantaneously measured water depths ranging from 7 to 63cm. Pond- and field-grown plants responded differently across the instantaneously measured water depth. Resistance to convective flow did not change in the culms of pond-grown plants whereas there was an increase in resistance in plants from the field with increasing instantaneously measured water depth. On the other hand, diffusive resistance remained constant in the developing rhizomes of field-grown plants but decreased with increasing water depth in pond-grown plants. Further, diffusive resistances in the rhizomes of field-grown plants were approximately twice those found in pond-grown plants. The rhizome length of pond plants was similar at all depths whereas field-grown plants showed a decrease in rhizome length with increasing instantaneously measured water depth, possibly reflecting the decrease in potential for aeration in the above-ground parts of the plant. The results suggest that a variable water regime may affect the performance of P. australis by constraining oxygen supply to the below-ground parts of the plant.