Dipartimento di Scienze Biologiche, Geologiche ed Ambientali (BiGeA) & Centro Interdipartimentale di Ricerca per le Scienze Ambientali (CIRSA), University of Bologna, CoNISMa, Ravenna, Italy.
Istituto di Scienze Marine, Consiglio Nazionale delle Ricerche, Bologna, Italy.
PLoS One. 2016 Oct 4;11(10):e0163494. doi: 10.1371/journal.pone.0163494. eCollection 2016.
Coralligenous biogenic reefs are among the most diverse marine habitats in the Mediterranean Sea. The northern Adriatic mesophotic coralligenous outcrops host very rich and diverse epibenthic assemblages. Several studies quantified the low temporal variability and high spatial heterogeneity of these habitats, while processes driving structuring and differentiation are still poorly understood. To shed light on these processes, temporal and spatial patterns of colonisation were investigated using travertine tiles deployed on three coralligenous outcrops, corresponding to the main typologies of benthic assemblages described in previous studies. Three years after deployment, assemblages colonising travertine tiles resembled the differentiation among sites revealed by the natural assemblages in terms of major ecological groups. Processes structuring and maintaining species diversity have been explored. Pioneer species with high reproduction rate, long distance larval dispersal and fast growth (e.g. the serpulid polychaete Spirobranchus triqueter and the bivalve Anomia ephippium), were the most abundant in the early stages of recruitment on the two outcrops further away from the coast and with lower sedimentation. Their success may vary according to larval availability and environmental conditions (e.g., sedimentation rates). At these sites early-stage lasted 10-12 months, during which even species from natural substrates began colonising tiles by settlement of planktonic propagules (e.g., encrusting calcareous Rhodophyta) and lateral encroachment (e.g., sponges and ascidians). On coastal outcrop, exposed to a higher sedimentation rates, tiles were colonised by fast-growing algal turfs. Resilience of northern Adriatic coralligenous assemblages, and maintenance of their diversity, appeared largely entrusted to asexual reproduction. Exploring the mechanisms that underlie the formation and maintenance of the species diversity is crucial to improve our understanding of ecological processes and to implement appropriate conservation strategies of the Adriatic coralligenous reefs.
造礁石珊瑚生物礁是地中海最具多样性的海洋栖息地之一。亚得里亚海北部中层造礁石珊瑚露头区拥有非常丰富多样的附着生物组合。几项研究量化了这些栖息地的低时间变异性和高空间异质性，而驱动结构和分化的过程仍知之甚少。为了阐明这些过程，使用部署在三个造礁石珊瑚露头区的石灰华瓦片研究了定殖的时间和空间模式，这三个露头区对应于先前研究中描述的主要底栖生物组合类型。部署三年后，附着在石灰华瓦片上的生物组合在主要生态群方面类似于通过自然组合揭示的站点之间的分化。探索了塑造和维持物种多样性的过程。具有高繁殖率、长距离幼虫扩散和快速生长的先锋物种（例如，多毛环节动物 S. triqueter 和双壳类 Anomia ephippium）在离海岸更远、沉降量更低的两个露头区的早期阶段，在生物量上最为丰富。它们的成功可能因幼虫的可用性和环境条件（例如沉降速率）而异。在这些地点，早期阶段持续 10-12 个月，在此期间，即使是来自自然基质的物种也开始通过浮游生物繁殖体（例如，固着的钙质红藻）的定居和侧向侵蚀（例如，海绵和海鞘）在瓦片上定殖。在沿海露头区，暴露于更高的沉降速率下，瓦片被快速生长的藻类草皮定殖。亚得里亚海北部造礁石珊瑚生物组合的恢复力及其多样性的维持在很大程度上依赖于无性繁殖。探索形成和维持物种多样性的机制对于提高我们对生态过程的理解和实施亚得里亚海造礁石珊瑚礁的适当保护策略至关重要。
