Interactions between wave action and grazing control the distribution of intertidal macroalgae.
Interactions between wave action and grazing control the distribution of intertidal macroalgae.
复制标题
波浪作用和放牧之间的相互作用控制着潮间带大型藻类的分布。
作者：
P. Jonsson;Lena Granhag;P. Moschella;P. Åberg;S. Hawkins;Richard C. Thompson
形成冠层的大型藻类是温带岩石海岸的关键物种。然而，人们对物理和生物因素的相对平衡如何控制潮间带大型藻类的建立和持续存在缺乏了解。在这里，我们提出了一个综合研究的相对重要性的波诱导力和放牧的招募和生存的冠层形成的潮间带大型藻类墨角藻水泡和F。螺旋形的一组漫顶防波堤提供了一个几乎不混淆的梯度，在向海和向陆侧之间的波暴露。基于破碎波中最大阻力的经验测量值、长期最大波高模型和墨角藻属的破碎应力，进行了生物力学分析。预计防波堤向海侧的最大流速（7-8 m/s）将完全驱逐或修剪墨角藻。大于约10厘米，而所有尺寸的向陆地一侧的移位是极不可能的。墨角藻的实验移植。支持生物力学分析，但也表明，机械磨损可能进一步限制在波暴露的位置生存。实验去除帽贝髌骨vulgata，这是在这个网站上的主要食草动物，导致墨角藻属的招聘。在向海的一边。我们提出了一个帽贝放牧模型，表明帽贝密度>5-20个个体/m2提供了阻止墨角藻建立的近似机制，而大于2 m/s的波浪作用通过移动和冲击降低了持久性。在一个概念模型中，我们进一步提出，招聘和生存的青少年墨角藻种。通过暴露位置处较高的帽贝密度，受波浪暴露间接控制。该模型预测，气候变化，特别是东北大西洋风暴事件频率的增加，将限制岩藻到更多的庇护场所。
Canopy-forming macroalgae are key species on temperate rocky shores. However, there is a lack of understanding of how the relative balance of physical and biological factors controls the establishment and persistence of intertidal macroalgae. Here we present an integrated study of the relative importance of wave-induced forces and grazing for the recruitment and survival of the canopy-forming intertidal macroalgae Fucus vesiculosus and F. spiralis. A set of overtopped breakwaters provided a nearly unconfounded gradient in wave exposure between seaward and landward sides. A biomechanical analysis was performed based on empirical measurements of maximum drag forces in breaking waves, a model of long-term maximum wave height, and the breaking stress of Fucus spp. The estimated maximum flow speed (7-8 m/s) on the seaward side of the breakwaters was predicted to completely dislodge or prune Fucus spp. larger than approximately 10 cm, while dislodgment was highly unlikely on the landward side for all sizes. Experimental transplantation of Fucus spp. supported the biomechanical analysis but also suggested that mechanical abrasion may further limit survival in wave-exposed locations. Experimental removal of the limpet Patella vulgata, which was the principal grazer at this site, resulted in recruitment of Fucus spp. on the seaward side. We present a model of limpet grazing that indicates that limpet densities >5-20 individuals/m2 provide a proximate mechanism preventing establishment of Fucus spp., whereas wave action >2 m/s reduces persistence through dislodgment and battering. In a conceptual model we further propose that recruitment and survival of juvenile Fucus spp. are controlled indirectly by wave exposure through higher limpet densities at exposed locations. This model predicts that climate change, and in particular an increased frequency of storm events in the northeast Atlantic, will restrict fucoids to more sheltered locations.