Marine hardground bottom (subtidal) benthic (sessile) communities (HBBC) are subjected to various biotic, abiotic, and anthropogenic factors that can vary over space and time and interact with one another. To evaluate the main drivers of the structure of HBBC in a large tropical bay in the southwest Atlantic (Ilha Grande Bay, Brazil), a total of 98 HBBC were sampled using visually estimated quadrats. Ten variables (depth, grazing intensity, irradiance, temperature, salinity, dissolved oxygen, nutrients (nitrite, nitrate, and phosphate), and chlorophyll a concentrations) were also measured. A total of 74 main space‐occupying taxon/functional groups were recorded which fell into six major HBBC groups. These were organized by depth/irradiance and grazing intensities which explained part of the HBBC variation: (a) Communities dominated by zoantharians occurred in the shallow, highest irradiance sites; (b) foliose and erect algae were inversely related to depth and grazing intensity; (c) crustose coralline algae dominated at greater depths and/or under higher grazing intensity; (d) zooxanthellate corals were associated with shallower and heterotrophic invertebrates with deeper stations; (e) photosynthetically efficient algae were associated with deeper stations, with more encrusting forms under higher grazing intensities; and (f) multi‐species turf‐forming algae were ubiquitous (did not present association with any of the measured variables). As communities’ components and main structuring factors were similar to those found in coral reefs, these communities represent compatible receptor habitats for poleward escape, migration, and range extension under the present global warming scenario.

中文翻译：

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深度和放牧强度是南大西洋热带珊瑚礁潮下硬底底栖生物群落结构的主要驱动力

海洋硬底（底潮）底栖（无柄）群落（HBBC）受到各种生物，非生物和人为因素的影响，这些因素会随时间和空间变化并相互影响。为了评估西南大西洋（巴西伊利亚格兰德湾）一个热带大湾中HBBC结构的主要驱动因素，使用视觉估计的四方方取样共采集了98个HBBC。十个变量（深度，放牧强度，辐照度，温度，盐度，溶解氧，养分（亚硝酸盐，硝酸盐和磷酸盐）和叶绿素a还测量了浓度。总共记录了74个主要的空间分类单元/功能组，分为6个主要的HBBC组。这些活动是由深度/辐照度和放牧强度来组织的，这解释了HBBC变化的部分原因：（a）由黄腐动物为主的社区发生在浅的，最高辐照度的地点；（b）叶藻和直立藻类与深度和放牧强度成反比；（c）在更深的深度和/或更高的放牧强度下以硬壳珊瑚藻为主；（d）黄藻类珊瑚与具较深站位的较浅和异养无脊椎动物有关；（e）光合作用高效的藻类与更深的站有关，在放牧强度较高的情况下具有更多的包壳形式；（f）多种草皮形成的藻类无处不在（没有与任何测量变量相关联）。由于社区的组成部分和主要结构因素与在珊瑚礁中发现的相似，因此这些社区代表了在当前全球变暖情况下极向性逃逸，迁移和范围扩展的相容受体生境。