CO2及光强对南麂列岛铜藻生长的影响

铜藻Sargassum horneri(Turner) C. Agardh是浙江沿海常见的大型海藻之一，对海洋生态系具有重要作用。近年来由于环境恶化，南麂列岛海域的大量铜藻藻场退化消失。因此探讨其退化机制，是维持沿海生态平衡和恢复藻场的重要理论基础。本研究对比研究了不同光强(低光，LL: 40～50 μmol·m-2·s-1；高光，HL: 100～110 μmol·m-2·s-1)、不同CO2浓度(低CO2浓度，LC: 076 μg·L-1；高CO2浓度，HC: 196 μg·L-1），对铜藻生长状况的影响，以期了解铜藻对环境胁迫的适应。结果表明: 1)高光条件下，铜藻的相对生长速率(RGR)为180%·d-1，是低光条件下(RGR=085%·d-1)的21倍；2)高CO2浓度能促进铜藻的生长，HC的RGR(289%·d-1)是LC(249%·d-1)的116倍；3)HL和HC培养的藻体，其株高和叶片数分别优于LL和LC的，但LL和LC的Chla含量高于前者。

Effect of CO2 concentration and irradiance on the growth of Sargassum horneri (Phaeophyceae) in Nanji Archipelago

Sargassum horneri(Turner) C. Agardh， one of the common macroalgae along the coast of Zhejiang Province， plays an important role in the marine ecosystem. Because of the environmental deterioration within decade years， S. horneri beds along the Nanji Archipelago had been degenerated. Therefore， to study the degenerated mechanism of S. horneri is the key point to keep littoral ecosystem balance and restore the macroalgae beds. In this study， we investigated the effect of two irradiance levels (low light， LL: 40-50 μmol·m-2·s-1; high light， HL: 100-110 μmol·m-2·s-1) and two CO2 concentrations (low CO2， LC: 076 μg·L-1; high CO2， HC: 196 μg·L-1) on the growth of S. horneri， in order to detect the response of this species to HL and HC. The results showed that the relative growth rate (RGR) of S. horneri in HL was 180%·d-1， 21 times of that grown in LC (085%·d-1). The RGRs were 289%·d-1 in HC and 249%·d-1 in LC， respectively， and the former was 116 times of the latter. Both the height of thalli and the number of leaves in treatments of HC and HL was higher than LC and LL， respectively， but the Chla contents were higher in LC and LL than in HC and HL， respectively．