long-term monitoring species size surveys of rocky intertidal ecosystems

The Baseline surveys of rocky intertidal ecosystems (SC) project includes both Long-Term Monitoring and Biodiversity Surveys done in the SouthCoast of California. Long-Term Monitoring Surveys use fixed plots to document changes in percent cover, or abundance of targeted species or species assemblages. This fixed-plot approach allows the dynamics of rocky intertidal species to be monitored with reasonable sampling effort and provides sufficient statistical power to detect changes over space or time. Biodiversity Surveys provide detailed information about biodiversity and community structure. These surveys were designed to measure diversity and abundance of algae and invertebrates found within rocky intertidal communities on the western coast of temperate North America. This metadata record documents the Long-Term Monitoring Species Size Surveys done as part of the SC Baseline surveys of rocky intertidal ecosystems. Total counts for species counted during these surveys are available in a separate Species Count dataset. Please note that counts for species measured in the Species Size dataset are already included in the Species Count dataset, and should not be added to those totals. Species Size sampling is conducted by recording the number and size of a specific organism found in a permanent plot at a given site. The plot type and number of replicates depends on the target species. Long-Term Monitoring Surveys are comprised of one or more of the following procedures: 1) Photoplots used to monitor percent cover in assemblages such as barnacles, mussels, and rockweed, as well as small, mobile species such as snails and hermit crabs, 2) Line transects used to estimate cover of surfgrass, kelps and other algae not well-sampled by photoplots. 3) Irregular plots used for counts and sizes of large, mobile species such as seastars and limpets. Long-Term Monitoring Surveys are done throughout the year at sites ranging from Alaska to Southern California.

加州南海岸（SouthCoast）岩质潮间带生态系统基线调查（SC）项目涵盖长期监测与生物多样性调查两类工作。长期监测调查采用固定样地法，记录目标物种或物种集合的盖度百分比或丰度变化。该固定样地方法可在合理采样工作量下实现岩质潮间带物种种群动态的监测，并具备足够的统计效力以检测空间或时间尺度上的变化。生物多样性调查则提供生物多样性与群落结构的详细信息，本类调查旨在量化温带北美西海岸岩质潮间带群落中藻类与无脊椎动物的多样性及丰度。本元数据记录所记录的是作为岩质潮间带生态系统SC基线调查组成部分的长期监测物种体型调查。本次调查中统计的物种总计数可在独立的《物种计数数据集（Species Count dataset）》中获取。请注意：《物种体型数据集（Species Size dataset）》中已测量物种的计数已包含于《物种计数数据集》中，无需重复计入总计数。物种体型采样通过记录特定调查点位永久样地内发现的特定生物的个体数量与体型大小开展，样地类型与重复采样次数取决于目标物种。长期监测调查包含以下一项或多项调查流程：1） 样方摄影法：用于监测藤壶、贻贝、岩藻等物种集合的盖度，以及螺、寄居蟹等小型移动物种的盖度；2） 样线法：用于估算无法通过样方摄影法有效采样的海草、巨藻及其他藻类的盖度；3） 不规则样地法：用于统计海星、帽贝等大型移动物种的个体数量与体型大小。长期监测调查全年开展，调查点位覆盖从阿拉斯加到南加利福尼亚的广大区域。