Data Sheet 1_Development amongst the seagrass Cymodocea nodosa influences the morphology of the brown algae Gongolaria barbata in a coastal lagoon of the northern Adriatic Sea.docx

Marine forests are declining worldwide and understanding the ecology of extant forests is crucial for developing practices that best conserve and restore them for the future. In the Mediterranean region, there has been an increasing effort to restore forest forming fucalean seaweeds and to understand the ecological context that supports their persistence. Here, we describe population metrics for a significant extant fucalean forest located in a coastal lagoon on the southern Istrian peninsula (Croatia). In Šćuza Lagoon, Gongolaria barbata settles within two main substrate types, on small stones and pebbles amongst seagrass Cymodocea nodosa and on rocky substrate provided by larger, more exposed boulders within the meadow but where seagrass does not grow. Amongst seagrass, G. barbata grew to a greater maximum height, observed during both its growth and dormant phases. On boulders, any disadvantage in height appeared to be offset by higher recruitment where the overall density was similar between the two areas. Opportunistic recruitment of G. barbata during the senescent period for C. nodosa appeared to contribute to their coexistence in this unique location and seagrasses appeared to reduce the prevalence of cauloid damage for G. barbata. These findings highlight the importance of understanding fine-scale ecological interactions that support the persistence of isolated patches of vulnerable marine forests.

全球范围内的海洋森林正持续衰退，明晰现存海洋森林的生态特征，对制定最优保护与修复方案以保障其未来存续至关重要。地中海区域内，人们正加大对形成森林的墨角藻目（Fucalean）海藻的修复力度，并深入探究支撑其存续的生态背景。本研究针对克罗地亚伊斯特拉半岛南部一处滨海潟湖中现存的大型墨角藻目森林，阐述其种群统计指标。在什图扎潟湖（Šćuza Lagoon）中，多肋马尾藻（Gongolaria barbata）主要定植于两类底质环境：一类是海神草（Cymodocea nodosa）床内的小石块与砾石之上，另一类是海草床内无海草生长的大型裸露岩礁底质。在海神草床内，多肋马尾藻的最大株高更高，这一现象在其生长季与休眠期均有观测到。在岩礁底质环境中，尽管株高存在劣势，但该区域更高的种群补充量弥补了这一不足，且两类生境的整体种群密度相近。多肋马尾藻在海神草的衰老期开展机会性定植，似乎助力二者在该独特生境中共存；同时海草似乎能降低多肋马尾藻茎状体的损伤发生率。本研究结果凸显了明晰精细尺度生态互作的重要性——这类互作支撑着脆弱海洋森林孤立斑块的存续。