Miller Sheryl M, Hurd Catriona L, Wing Stephen R
Department of Botany, University of Otago, PO Box 56, Dunedin, New ZealandDepartment of Marine Science, University of Otago, PO Box 56, Dunedin, New Zealand.
J Phycol. 2011 Jun;47(3):505-516. doi: 10.1111/j.1529-8817.2011.00966.x. Epub 2011 Apr 25.
Spatial and temporal patterns of growth, erosion, productivity, and morphology of the dominant habitat-forming kelp Ecklonia radiata (C. Agardh) J. Agardh were studied bimonthly over 1.5 years in a southern New Zealand fjord characterized by strong gradients in light and wave exposure. Spatial differences in growth were observed with rates at two outer coast, high-light, wave-exposed sites reaching 0.42 and 0.45 cm · d , respectively, compared to 0.27 cm · d at an inner, more homogeneous site. Sporophyte productivity was similar among sites, although population productivity was greater at the outer sites due to population density being 5-fold greater than at the inner site. It was expected that the inner site would have no pronounced seasonal pattern in growth and productivity due to its homogeneity; however, all three sites displayed maximum rates in late winter/spring and minimal in autumn. Growth rates were 2-fold greater during the first growth period than the following year. This discrepancy was not correlated to inorganic nitrogen (N) levels, which remained low year-round (<4 μM), and is likely a result of an interaction between light and temperature, and the photosynthetic capability of E. radiata. Variable pigment content indicated photoacclimation at the inner site. Morphological differences were observed between sites, with E. radiata from the inner site having longer, wider, thinner blades and longer stipes. While E. radiata displayed spatial differences in growth, erosion, productivity, and morphology, populations displayed no temporal differences. These results highlight the need for greater understanding of the mechanisms influencing kelp growth and productivity in a unique marine environment.
在新西兰南部一个以光照和波浪暴露梯度较大为特征的峡湾中，对主要的造礁海带辐射型昆布（Ecklonia radiata (C. Agardh) J. Agardh）的生长、侵蚀、生产力和形态的时空模式进行了为期1.5年的双月研究。观察到生长存在空间差异，两个外海高光照、波浪暴露站点的生长速率分别达到0.42和0.45厘米·天，而内湾一个更均匀站点的生长速率为0.27厘米·天。各站点的孢子体生产力相似，尽管外海站点的种群生产力更高，因为其种群密度比内湾站点大5倍。预计内湾站点由于其均匀性，生长和生产力不会有明显的季节性模式；然而，所有三个站点在冬末/春季生长速率最高，秋季最低。第一个生长时期的生长速率比次年高出2倍。这种差异与全年保持低水平（<4 μM）的无机氮（N）水平无关，可能是光照和温度相互作用以及辐射型昆布光合能力的结果。可变的色素含量表明内湾站点存在光适应现象。站点之间观察到形态差异，内湾站点的辐射型昆布叶片更长、更宽、更薄，叶柄更长。虽然辐射型昆布在生长、侵蚀、生产力和形态上存在空间差异，但种群没有时间差异。这些结果凸显了在独特海洋环境中更深入了解影响海带生长和生产力机制的必要性。
