Khan Tasnuva Ming, Griffiths Huw J, Stephenson Nile P, Whittle Rowan J, Purser Autun, Manica Andrea, Mitchell Emily G
Department of Zoology, University of Cambridge, Downing St, Cambridge, CB2 3EJ, UK.
British Antarctic Survey, High Cross, Madingley Rd, Cambridge, CB3 0ET, UK.
Sci Rep. 2025 May 24;15(1):18121. doi: 10.1038/s41598-025-02282-7.
Coexistence of ecologically similar taxa can contribute considerably to local biodiversity patterns. Deep water Southern Ocean benthic communities provide a unique setting to investigate coexistence mechanisms due to the relatively pristine nature of Antarctic ecosystems and a lack of disturbances like ice scour or top-down predator control. Here, we examine cup coral populations on the deep (~ 2000 m) rocky slopes of Powell Basin, Weddell Sea-an ecosystem with dense and speciose epibenthic communities. We investigate the spatial ecology of two coral morphotypes-"orange" and "pink" cup corals (likely Caryophyllia or Flabellum) using high-resolution seabed images from the RV Polarstern cruise PS118. Across 36 sites, we recorded 3431 pink and 1545 orange corals, which formed both mixed and single-population dominant (where either morph was near absent) communities. Spatial point process analysis revealed that reproductive processes drive their spatial patterns, with orange corals showing consistent dispersal behaviour regardless of community type. In contrast, pink corals exhibited greater dispersal plasticity in mixed populations, significantly increasing dispersal distances, suggesting that they are the weaker competitors. Our results suggest that in these deep water hard substrate Antarctic communities, dispersal plasticity has the ability to enable coexistence of ecologically similar morphs, thereby increasing alpha diversity.
生态相似的分类群共存对当地生物多样性模式有很大贡献。南大洋深水底栖生物群落提供了一个独特的环境来研究共存机制，这是由于南极生态系统相对原始，且缺乏诸如冰蚀或自上而下的捕食者控制等干扰。在这里，我们研究了威德尔海鲍威尔盆地深处（约2000米）岩石斜坡上的杯形珊瑚种群——这是一个具有密集且物种丰富的浅水底栖生物群落的生态系统。我们使用“极地stern号”科考船PS118航次的高分辨率海底图像，研究了两种珊瑚形态型——“橙色”和“粉色”杯形珊瑚（可能是石芝珊瑚属或扇形珊瑚属）的空间生态学。在36个站点，我们记录了3431只粉色珊瑚和1545只橙色珊瑚，它们形成了混合种群和单一种群占主导（其中一种形态几乎不存在）的群落。空间点过程分析表明，繁殖过程驱动了它们的空间格局，橙色珊瑚无论群落类型如何，都表现出一致的扩散行为。相比之下，粉色珊瑚在混合种群中表现出更大的扩散可塑性，显著增加了扩散距离，这表明它们是较弱的竞争者。我们的结果表明，在这些南极深水区硬底质群落中，扩散可塑性有能力使生态相似的形态共存，从而增加局部多样性。
