UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, Western Australia, 6009, Australia.
UWA Oceans Institute and Oceans Graduate School, University of Western Australia, Crawley, Western Australia, 6009, Australia.
J Phycol. 2022 Dec;58(6):760-772. doi: 10.1111/jpy.13285. Epub 2022 Oct 5.
Cystophora is the second largest genus of fucoids worldwide and, like many other forest-forming macroalgae, is increasingly threatened by a range of anthropogenic impacts including ocean warming. Yet, limited ecological information is available from the warm portion of their range (SW Western Australia), where severe range contractions are predicted to occur. Here, we provide the first insights on the abundance, diversity, productivity, and stand structure of Cystophora forests in this region. Forests were ubiquitous over more than 800 km of coastline and dominated sheltered and moderately-exposed reefs. Stand biomass and productivity were similar or greater than that of kelp forests in the temperate reef communities examined, suggesting that Cystophora spp. play a similarly important ecological role. The stand structure of Cystophora forests was, however, different than those of kelp forests, with most stands featuring an abundant bank of sub-canopy juveniles and only a few plants forming the canopy layer. Stand productivity followed an opposite seasonal pattern than that of kelps, with maximal growth in late autumn through early winter and net biomass loss in summer. Annually, stands contributed between 2.2 and 5.7 kg · m (fresh biomass) to reef productivity depending on the dominant stand species. We propose that Cystophora forests play an important and unique role in supporting subtidal temperate diversity and productivity throughout temperate Australia, and urge a better understanding of their ecology and responses to anthropogenic threats.
藻体是全球第二大墨角藻属，与许多其他形成森林的大型藻类一样，受到包括海洋变暖在内的一系列人为影响的威胁越来越大。然而，在其温暖分布区（西澳大利亚西南部），可用的生态信息有限，预计该地区的分布范围将严重收缩。在这里，我们首次提供了该地区藻体森林丰富度、多样性、生产力和林分结构的见解。森林在超过 800 公里的海岸线上无处不在，主要分布在受庇护和中度暴露的珊瑚礁上。林分生物量和生产力与温带珊瑚礁群落中褐藻林的相似或更高，这表明藻体 spp. 发挥着类似的重要生态作用。然而，藻体森林的林分结构与褐藻林不同，大多数林分特征是丰富的亚冠层幼体，只有少数植物形成冠层。林分生产力的季节性模式与褐藻相反，晚秋至初冬生长最快，夏季净生物量损失。每年，根据主要林分物种的不同，林分对珊瑚礁生产力的贡献在 2.2 至 5.7 公斤·米（新鲜生物量）之间。我们提出，藻体森林在支持澳大利亚温带地区的亚潮带多样性和生产力方面发挥着重要而独特的作用，并敦促更好地了解它们的生态和对人为威胁的反应。
