CAJ | 학술논문

为了解水华引起的水体无机碳变化对沉水植物生长的影响,对8种沉水植物:金鱼藻、穗花狐尾藻、篦齿眼子菜、光叶眼子菜、微齿眼子菜、伊乐藻、菹草和黑藻在不同无机碳浓度下的生物量、株高、叶绿素以及光合和呼吸速率进行了比较研究.结果表明8种沉水植物均能利用HCO_3~-作为光合无机碳源,在1.5 mmoL/L外源HCO_3~-浓度下能促进金鱼藻、菹草和伊乐藻的生长,提高其光合速率;在2.5 mmol/L外源HCO_3~-浓度下能促进狐尾藻、光叶眼子菜、黑藻、微齿眼子菜和蓖齿眼子菜的生长,提高其光合速率.在CO_3~(2-)为优势碳源时,8种沉水植物表现出不同的适应性,发现微齿眼子菜、篦齿眼子菜和黑藻在整个实验范围内生长未受抑制,且在不同浓度下表现生长和光合速率的促进,说明这三种沉水植物对[HCO_3~-]/[CO_3~(2-)]比值和pH具有较广适应范围.而当CO_3~(2-)成为优势碳源时,金鱼藻和伊乐藻的生长受到抑制,狐尾藻、菹草和光叶眼子菜均死亡,表明[HCO_3~-]/[CO_3~(2-)]比值和pH是这5种沉水植物生长的重要限制因子.
위료해수화인기적수체무궤탄변화대침수식물생장적영향,대8충침수식물:금어조、수화호미조、비치안자채、광협안자채、미치안자채、이악조、저초화흑조재불동무궤탄농도하적생물량、주고、협록소이급광합화호흡속솔진행료비교연구.결과표명8충침수식물균능이용HCO_3~-작위광합무궤탄원,재1.5 mmoL/L외원HCO_3~-농도하능촉진금어조、저초화이악조적생장,제고기광합속솔;재2.5 mmol/L외원HCO_3~-농도하능촉진호미조、광협안자채、흑조、미치안자채화비치안자채적생장,제고기광합속솔.재CO_3~(2-)위우세탄원시,8충침수식물표현출불동적괄응성,발현미치안자채、비치안자채화흑조재정개실험범위내생장미수억제,차재불동농도하표현생장화광합속솔적촉진,설명저삼충침수식물대[HCO_3~-]/[CO_3~(2-)]비치화pH구유교엄괄응범위.이당CO_3~(2-)성위우세탄원시,금어조화이악조적생장수도억제,호미조、저초화광협안자채균사망,표명[HCO_3~-]/[CO_3~(2-)]비치화pH시저5충침수식물생장적중요한제인자.
Dissolved inorganic carbon (DIC) is a fundamental resource for photosynthesis of plants. The forms of DIC in water include CO_2, HCO_3~- and CO_3~(2-). Recent studies have shown that DIC potentially limited the growth and photosynthesis of several submerged macrophytes. In order to elucidate the impacts of the states of DIC in hyper-eutrophic lakes caused by water bloom on the growth of submerged macrophytes, the growth, chlorophyll and photosynthetic and respiration rates of eight species of submerged macrophytes, including Ceratophyllum demersum, Myriophyllum spicatum, Potamogeton pec-tinatus, Potamogeton lucens, Potamogeton maackianus, Elodea nattalii, Potamogeton crispus and Hydrilla verticillata, were investigated under different DIC conditions. The results indicated that HCO_3~- could be used as a carbon source by all the submerged macrophytes tested. Improvement of growth and photosynthetic rates was found on C. demersum, P. crispus and E. nattalii under exogenous HCO_3~- below 1.5 mmol/L, and also on M. spicatum, P. lucens, H. verticillata, P. maackianus and P. pectinatus under exogenous HCO_3~- below 2.5 mmol/L, however, when CO_3~(2-) acted as the dominate carbon source, different effects were found on the eight kinds of submerged macrophytes. Growth and photosynthetic rates of P. maackianus, P. pectinatus and H. verticillata were not inhibited, and showed improvement under certain CO_3~(2-) concentrations , which indicated that the three species of macrophytes could adapt to a wide range of [HCO_3~-] / [CO_3~(2-)] ratio and pH value. In contrast, the growth of C. demersum and E. nattalii were inhibited, and M. spicatum, P. crispus and P. lucens were died under the conditions of CO_3~(2-) as dominate carbon source, indicating [HCO_3~-]/ [CO_3~(2-)] ratio and pH values were the important limiting factors of growth for the above 5 species of submerged macrophytes.