Variation in the morphology, reproduction and development of the habitat-forming kelp Ecklonia radiata with changing temperature and nutrients
Variation in the morphology, reproduction and development of the habitat-forming kelp Ecklonia radiata with changing temperature and nutrients
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DOI：
10.3354/meps10261
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发表时间：
2013-01-01
影响因子：
2.5
通讯作者：
Wright, Jeffrey T.
中科院分区：
文献类型：
--
作者：
Mabin, Christopher J. T.;Gribben, Paul E.;Wright, Jeffrey T.
海洋温度升高对世界多个地区的海带森林构成威胁。在这项研究中，我们研究了东澳大利亚洋流 (EAC) 增强引起的海洋温度和相关硝酸盐浓度的变化将如何影响澳大利亚东南部广泛分布的海带 Ecklonia radiata 的形态、繁殖和发育。在新南威尔士州 (NSW) 和塔斯马尼亚州的海面温度相差约 5 摄氏度的地点检查了辐射 E. radiata 的形态和繁殖，并进行了实验室实验，以测试温度和营养物质对 E. radiata 发育的相互作用影响。与新南威尔士州相比，塔斯马尼亚岛较冷水域的辐射 E. radiata 尺寸和生殖组织数量通常更大。重要的是，一种形态特征（叶片长度）是繁殖组织数量的有力预测因子，这表明响应温度升高的形态变化可能会影响辐射桉的繁殖能力。配子体的生长在 15 至 22 摄氏度之间最为适宜，在 22 摄氏度以上则下降超过 50%。微观孢子体在 15 至 22 摄氏度之间也最大，但在 22 摄氏度以上没有孢子体发育，这突显了塔斯马尼亚辐射桉的潜在临界温度上限。较低的硝酸盐浓度对辐射桉配子体和孢子体没有影响。鉴于预计到 2100 年，澳大利亚东南部的海洋温度将上升 2 至 3 摄氏度，这些发现表明，辐射 E. radiata 可能会受到加强的 EAC 的影响，并强调早期生命周期阶段的发育和生长对这些变化的敏感性。
Increasing ocean temperatures are a threat to kelp forests in several regions of the world. In this study, we examined how changes in ocean temperature and associated nitrate concentrations driven by the strengthening of the East Australian Current (EAC) will influence the morphology, reproduction and development of the widespread kelp Ecklonia radiata in southeastern Australia. E. radiata morphology and reproduction were examined at sites in New South Wales (NSW) and Tasmania, where sea surface temperature differs by similar to 5 degrees C, and a laboratory experiment was conducted to test the interactive effects of temperature and nutrients on E. radiata development. E. radiata size and amount of reproductive tissue were generally greater in the cooler waters of Tasmania compared to NSW. Importantly, one morphological trait (lamina length) was a strong predictor of the amount of reproductive tissue, suggesting that morphological changes in response to increased temperature may influence reproductive capacity in E. radiata. Growth of gametophytes was optimum between 15 and 22 degrees C and decreased by >50% above 22 degrees C. Microscopic sporophytes were also largest between 15 and 22 C, but no sporophytes developed above 22 degrees C, highlighting a potentially critical upper temperature threshold for E. radiata in Tasmania. Lower nitrate concentration had no effect on E. radiata gametophytes and sporophytes. Given forecast increases in ocean temperature of between 2 and 3 degrees C in southeastern Australia by 2100, these findings suggest that E. radiata is likely to be affected by a strengthening EAC and highlight the susceptibility of the development and growth of early life-cycle stages to these changes.