High-latitude marginal reefs support fewer but bigger corals than their tropical counterparts

Anthropogenic impacts are typically detrimental to tropical coral reefs, but the effect of increasing environmental stress and variability on the size structure of coral communities remains poorly understood. This limits our ability to effectively conserve coral reef ecosystems because size-specific dynamics are rarely incorporated. Our aim is to quantify variation in the size structure of coral populations across 20 sites along a tropical-to-subtropical environmental gradient on the east coast of Australia (~23°S to 30°S), to determine how size structure changes with a gradient of sea surface temperature, turbidity, productivity and light levels. We use two approaches: 1) linear regression with summary statistics (such as median size) as response variables, a method frequently favoured by ecologists; and 2) compositional functional regression, a novel method using entire size-frequency distributions as response variables. We then predict coral population size structure with increasing ..., Images of the benthos were taken using SCUBA. Data from the images were extracted using the programme 'ImageJ', following the 'SizeExtractR' protocol. , R/ RStudio to run the code used in our analyses.

人为影响（Anthropogenic impacts）通常对热带珊瑚礁（tropical coral reefs）造成损害，但日益加剧的环境压力及其波动对珊瑚群落（coral communities）大小结构的影响仍未得到充分认知。这限制了我们有效保护珊瑚礁生态系统的能力，因为体型特异性动态（size-specific dynamics）极少被纳入保护考量范畴。本研究旨在量化澳大利亚东海岸（约南纬23°至30°）沿热带-亚热带环境梯度的20个样地中珊瑚种群（coral populations）的大小结构变异情况，以探明大小结构如何随海表温度、浊度、初级生产力与光照水平的梯度变化而改变。本研究采用两种分析方法：其一为以汇总统计量（如体型中位数）作为响应变量的线性回归（linear regression），这是生态学界常用的分析手段；其二为组成型功能回归（compositional functional regression），这是一种以完整体型频率分布作为响应变量的新型分析方法。随后我们将针对不断加剧的[原文未完整给出的环境因子]情景，预测珊瑚种群的大小结构。研究人员借助水肺潜水（SCUBA）获取了底栖生物（benthos）的影像数据。影像数据采用遵循SizeExtractR操作流程的ImageJ软件进行提取。本研究使用R/RStudio运行分析所用的代码。