Rocky intertidal sessile organisms, Western Prince of Wales Island, Alaska, U.S., Summer 2018.

Rocky intertidal ecology has had a long history of attempting to identify ecosystem patterns, associations, and the underlying mechanisms of each. Biotic (competition, predation, and trophic cascades) and abiotic (slope, rugosity, aspect, wave exposure, etc.) factors have been shown to influence rocky intertidal ecosystems, but these characteristics are highly variable on the beaches of Prince of Wales and surrounding islands (POW). The shoreline is highly complex, resulting in drastic shifts in environmental parameters. Sea otters, a species shown to restructure kelp ecosystems through predation pressure, were reintroduced to POW fifty years ago and their subsequent expansion created a gradient of sea otter occupation time among rocky intertidal sites. Due to the complexity of environmental and biological forces occurring at rocky intertidal beaches on POW, this study was conducted to measure the vertical distribution of sessile organisms as a metric of rocky intertidal community composition. The frequency of occurrence of primary substrate occupants can be used to assess the interactions and relative importance of biotic and abiotic forces on the rocky intertidal ecosystems of POW. Site information can be found in the "Rocky intertidal site information, Western Prince of Wales Island, Alaska, U.S., Summer 2018" data package. The elevation of major biobands at these sites can be found in the "Rocky intertidal bioband elevation, Western Prince of Wales Island, Alaska, U.S., Summer 2018" data package. The mobile invertebrate data at these sites can be found in the "Rocky intertidal mobile invertebrate, Western Prince of Wales Island, Alaska, U.S., Summer 2018" data package.潮间带岩石生态学（rocky intertidal ecology）领域长期致力于探索生态系统格局、群落关联及其各自的内在作用机制。研究表明，生物因子（biotic factors，涵盖竞争、捕食与营养级联（trophic cascades））与非生物因子（abiotic factors，包括坡度、粗糙度（rugosity）、坡向（aspect）、波浪暴露度（wave exposure）等）均会对潮间带岩石生态系统产生影响，但威尔士亲王岛及周边群岛（POW）的潮间带海滩上，上述特征存在极高的变异性。该区域海岸线构造极为复杂，致使环境参数发生剧烈波动。海獭（sea otters）作为一类可通过捕食压力重构巨藻（kelp）生态系统的物种，于50年前被重新引入POW区域，随后其种群扩张在潮间带岩石样地间形成了海獭占据时长的梯度分布。鉴于POW区域潮间带海滩上环境与生物作用力的复杂性，本研究通过测定固着生物（sessile organisms）的垂直分布，以此作为潮间带岩石群落组成的量化指标。基底主要定居者的出现频率，可用于评估POW区域潮间带岩石生态系统中生物与非生物作用力的相互关系及其相对重要性。样地相关信息可从"Rocky intertidal site information, Western Prince of Wales Island, Alaska, U.S., Summer 2018"数据包中获取；上述样地主要生物带（bioband）的海拔数据可查阅"Rocky intertidal bioband elevation, Western Prince of Wales Island, Alaska, U.S., Summer 2018"数据包；这些样地的移动无脊椎动物（mobile invertebrate）数据可从"Rocky intertidal mobile invertebrate, Western Prince of Wales Island, Alaska, U.S., Summer 2018"数据包中获取。