Grazing by sea urchins at the margins of barren patches on Mediterranean rocky reefs
Grazing by sea urchins at the margins of barren patches on Mediterranean rocky reefs
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DOI：
10.1007/s00227-013-2244-2
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发表时间：
2013-09-01
期刊：
影响因子：
2.4
通讯作者：
Bulleri, Fabio
中科院分区：
文献类型：
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作者：
Bulleri, Fabio
海胆，Paracentrotus lividus和Arbacia lixula，在形成和持续的贫瘠地区占主导地位的结壳珊瑚大型藻类所发挥的作用尚未完全阐明。这项研究，在西北地中海（43 A度30 'N，10A度20' E）之间进行2005年2月和2006年4月，调查如何在一个或两个海胆物种的损失或密度下降影响恢复直立大型藻类站（占主导地位的丝状形式）在贫瘠地区的边缘。在4-6 m深度，将3个贫瘠斑块分别分配给以下处理：（1）对照（自然密度为A. lixula和P. lividus）;（3）完全去除A.（4）50%的青叶胆自然密度和50%的白纹伊蚊自然密度;（5）对青叶胆的清除率和青叶胆的自然密度;（6）两种植物自然密度的50%; lixula和P. lividus; lixula和P. lividus。草食动物治疗的影响进行了评估，无论是在存在或不存在的结壳珊瑚。部分或全部切除A。lixula、P. lividus或两者都有利于丝状大型藻类在贫瘠斑块边缘的增殖。结壳珊瑚的存在减少了这些大型藻类的发展。这项研究的结果表明，适度减少密度的两个物种之一，可以降低草食动物组合的能力，以控制在贫瘠的补丁边缘的丝状大型藻类的增殖。因此，贫瘠地区的范围似乎受到两种海胆之间依赖密度的相互作用的结果的调节。
The role played by the urchins, Paracentrotus lividus and Arbacia lixula, in the formation and persistence of barren areas dominated by encrusting coralline macroalgae is yet to be fully elucidated. This study, carried out in the NW Mediterranean (43A degrees 30'N, 10A degrees 20'E) between February 2005 and April 2006, investigated how the loss or density decrease in one or both urchin species influences the recovery of erect macroalgal stands (dominated by filamentous forms) at the margins of barren areas. At a depth of 4-6 m, three barren patches were assigned to each of the following treatments: (1) control (natural densities of A. lixula and P. lividus); (2) 50 % of the natural density of A. lixula and natural density of P. lividus; (3) total removal of A. lixula and natural density of P. lividus; (4) 50 % of the natural density of P. lividus and natural density of A. lixula; (5) total removal of P. lividus and natural density of A. lixula; (6) 50 % of the natural densities of both A. lixula and P. lividus; (7) total removal of both A. lixula and P. lividus. The effects of the herbivore treatments were evaluated either in the presence or the absence of encrusting corallines. The partial or total removal of A. lixula, P. lividus or both favored the proliferation of filamentous macroalgae at the margins of barren patches. The presence of encrusting corallines reduced the development of these macroalgae. The results of this study suggest that a moderate decrease in the density of just one of the two species can decrease the ability of the herbivore assemblage to control the proliferation of filamentous macroalgae at the margins of barren patches. The extent of barren areas appears, therefore, to be regulated by the outcome of density-dependent interactions between the two species of sea urchins.