Abstract
Blooms of ulvoid macroalgae (mainly Enteromorpha and Ulva) have covered 80% of the intertidal seagrass bed at Wanlitung, southern Taiwan, effectively shading the seagrasss species Thalassia hemprichii resulting in a decrease in photosynthetic performance and low inorganic carbon (Ci) uptake. We looked for evidence of Ci limitation and investigated the C i utilization characteristics of ulvoid-free and ulvoid-covered T. hemprichii. The rapid light curve (RLC) function of the Diving-PAM (Diving-PAM, Walz, Germany) was used to measure in situ photosynthetic performance (based on the effective quantum yield of PSII [Y] values) of intact seagrasses that were placed in small incubating chambers. Significantly, a lower RETRmax (maximum relative electron transport rate) and Ek (light intensity at the onset of saturation) were noted in the ulvoid-covered compared to the ulvoid-free T. hemprichii, suggesting that the former has acclimatized to the low light environment becoming a "shade type" plant. The ulvoid-covered T. hemprichii showed some evidence of Ci limitation since a significant increase in RETRmax (up to 46%; P < 0.05) was noted after an increase in the concentration of NaHCO3 from 2.2 (normal seawater) to 6.2 mM. In terms of Ci utilization characteristics, T. hemprichii could directly absorb HCO3- as the major Ci source but partially depended on the extracellular carbonic anhydrase (CA) to convert HCO3- to CO2 prior to uptake in the ulvoid-free, high light-adapted populations. A wastewater stream with a high nutrient load coming from the urbanized area may have caused the frequent blooms of ulvoid macroalgae.
| Original language | English |
|---|---|
| Pages (from-to) | 197-203 |
| Number of pages | 7 |
| Journal | Botanical Bulletin of Academia Sinica |
| Volume | 46 |
| Issue number | 3 |
| Publication status | Published - 2005 Jul 1 |
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All Science Journal Classification (ASJC) codes
- Plant Science
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The effect of ulvoid macroalgae on the inorganic carbon utilization by an intertidal seagrass Thalassia hemprichii. / Liu, Shao Lun; Wang, Wei Lung; Danilo, T. D.Y.; Fu, Cheng Chang.
In: Botanical Bulletin of Academia Sinica, Vol. 46, No. 3, 01.07.2005, p. 197-203.Research output: Contribution to journal › Article
TY - JOUR
T1 - The effect of ulvoid macroalgae on the inorganic carbon utilization by an intertidal seagrass Thalassia hemprichii
AU - Liu, Shao Lun
AU - Wang, Wei Lung
AU - Danilo, T. D.Y.
AU - Fu, Cheng Chang
PY - 2005/7/1
Y1 - 2005/7/1
N2 - Blooms of ulvoid macroalgae (mainly Enteromorpha and Ulva) have covered 80% of the intertidal seagrass bed at Wanlitung, southern Taiwan, effectively shading the seagrasss species Thalassia hemprichii resulting in a decrease in photosynthetic performance and low inorganic carbon (Ci) uptake. We looked for evidence of Ci limitation and investigated the C i utilization characteristics of ulvoid-free and ulvoid-covered T. hemprichii. The rapid light curve (RLC) function of the Diving-PAM (Diving-PAM, Walz, Germany) was used to measure in situ photosynthetic performance (based on the effective quantum yield of PSII [Y] values) of intact seagrasses that were placed in small incubating chambers. Significantly, a lower RETRmax (maximum relative electron transport rate) and Ek (light intensity at the onset of saturation) were noted in the ulvoid-covered compared to the ulvoid-free T. hemprichii, suggesting that the former has acclimatized to the low light environment becoming a "shade type" plant. The ulvoid-covered T. hemprichii showed some evidence of Ci limitation since a significant increase in RETRmax (up to 46%; P < 0.05) was noted after an increase in the concentration of NaHCO3 from 2.2 (normal seawater) to 6.2 mM. In terms of Ci utilization characteristics, T. hemprichii could directly absorb HCO3- as the major Ci source but partially depended on the extracellular carbonic anhydrase (CA) to convert HCO3- to CO2 prior to uptake in the ulvoid-free, high light-adapted populations. A wastewater stream with a high nutrient load coming from the urbanized area may have caused the frequent blooms of ulvoid macroalgae.
AB - Blooms of ulvoid macroalgae (mainly Enteromorpha and Ulva) have covered 80% of the intertidal seagrass bed at Wanlitung, southern Taiwan, effectively shading the seagrasss species Thalassia hemprichii resulting in a decrease in photosynthetic performance and low inorganic carbon (Ci) uptake. We looked for evidence of Ci limitation and investigated the C i utilization characteristics of ulvoid-free and ulvoid-covered T. hemprichii. The rapid light curve (RLC) function of the Diving-PAM (Diving-PAM, Walz, Germany) was used to measure in situ photosynthetic performance (based on the effective quantum yield of PSII [Y] values) of intact seagrasses that were placed in small incubating chambers. Significantly, a lower RETRmax (maximum relative electron transport rate) and Ek (light intensity at the onset of saturation) were noted in the ulvoid-covered compared to the ulvoid-free T. hemprichii, suggesting that the former has acclimatized to the low light environment becoming a "shade type" plant. The ulvoid-covered T. hemprichii showed some evidence of Ci limitation since a significant increase in RETRmax (up to 46%; P < 0.05) was noted after an increase in the concentration of NaHCO3 from 2.2 (normal seawater) to 6.2 mM. In terms of Ci utilization characteristics, T. hemprichii could directly absorb HCO3- as the major Ci source but partially depended on the extracellular carbonic anhydrase (CA) to convert HCO3- to CO2 prior to uptake in the ulvoid-free, high light-adapted populations. A wastewater stream with a high nutrient load coming from the urbanized area may have caused the frequent blooms of ulvoid macroalgae.
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M3 - Article
AN - SCOPUS:24944458424
VL - 46
SP - 197
EP - 203
JO - Botanical Studies
JF - Botanical Studies
SN - 1817-406X
IS - 3
ER -