Coleman Ross A, Underwood Antony J, Benedetti-Cecchi Lisandro, Aberg Per, Arenas Francisco, Arrontes Julio, Castro João, Hartnoll Richard G, Jenkins Stuart R, Paula José, Della Santina Paolo, Hawkins Stephen J
School of Biological Sciences, University of Southampton, SO16 7PX, Southampton, UK.
Oecologia. 2006 Mar;147(3):556-64. doi: 10.1007/s00442-005-0296-9. Epub 2006 Feb 1.
It is critical for our knowledge of biodiversity and ecosystem processes to understand how individual species contribute to ecosystem processes and how these contributions vary in space and time. We used a manipulative field experiment in five locations over 17 degrees of latitude [from southern Portugal to the Isle of Man (British Isles)] to determine the relative response of rocky intertidal algal assemblages released from control by the grazing of limpets. Response ratios showed that when limpets were removed there was a trend of effects from north to south. In the north, grazing had a strong effect on algal assemblages, but removing grazers reduced spatial variability in assemblages. In the south, the effect of limpet grazing was far weaker and removal of grazers had a much reduced impact on spatial variability. Here we show a clear trophic control of an ecosystem in that grazing by limpets not only determines macroalgal abundance overall but also modifies ecosystem stability via variability in cover of algae.
了解单个物种如何影响生态系统过程以及这些影响如何随时间和空间变化，对于我们认识生物多样性和生态系统过程至关重要。我们在跨越17个纬度（从葡萄牙南部到马恩岛（不列颠群岛））的五个地点进行了一项操纵性野外实验，以确定帽贝放牧解除控制后岩石潮间带藻类群落的相对反应。反应比率表明，移除帽贝后，存在从北到南的影响趋势。在北方，放牧对藻类群落有强烈影响，但移除食草动物会降低群落的空间变异性。在南方，帽贝放牧的影响要弱得多，移除食草动物对空间变异性的影响也大大降低。在这里，我们展示了对一个生态系统的明显营养控制，即帽贝放牧不仅决定了大型藻类的总体丰度，还通过藻类覆盖的变异性改变了生态系统的稳定性。
