School of Ocean Sciences, Bangor University, Askew St, Menai Bridge LL59 5AB, UK.
Department of Life Sciences, Aberystwyth University, Aberystwyth SY23 3DA, UK.
Sci Total Environ. 2024 Jan 1;906:167494. doi: 10.1016/j.scitotenv.2023.167494. Epub 2023 Oct 6.
Intertidal artificial habitats are proliferating, but are generally simpler in structure and host lower biodiversity than natural rocky reefs. Eco-engineering aims to enhance the biodiversity of coastal infrastructure, often through physical structural modifications that mimic topographic properties of natural shores. Relationships between biotic assemblages and structural properties of natural and artificial reefs have been extensively studied at sampling scales of up to 1 m. But evidence that quantified local structural variation has an appreciable influence on biotic assemblages, at a shore-wide scale across regional environmental gradients, is lacking. Here we addressed this knowledge gap with an observational study at 32 natural and artificial intertidal reef sites in Wales, UK. We used multivariate community analysis and permutation tests to examine associations between local physical structure, regional environmental variables and sessile biotic assemblages. A potential influence of local habitat structure on assemblage composition was evident across regional-scale environmental gradients. Compared to natural sites, artificial reefs had lower taxonomic richness, distinct and more variable assemblage composition, and different physical structure. After removing the effect of habitat (natural or artificial), canonical correspondence analysis showed that environmental variables (wave exposure, sea surface temperature and salinity variation), along with two metrics of physical structure (standard deviation in log-transformed detrended roughness and skewness of surface verticality, both at 0.5 m scale), explained 40 % of the variation in assemblage composition among sites. The two structural metrics independently explained 14.5 % of the variation. Associations identified between individual taxa and environmental variables indicated that sites with a higher proportion of horizontal surfaces hosted more canopy macroalgae, which in turn support other algae and invertebrates. Our findings provide evidence to inform scaling-up of structural eco-engineering interventions from experimental contexts to enhance the biodiversity of coastal infrastructure across regional extents.
潮间带人工生境正在大量增加，但与天然岩石礁相比，其结构通常较为简单，生物多样性也较低。生态工程旨在提高沿海基础设施的生物多样性，通常通过物理结构改造来实现，这些改造模仿了天然海岸的地形特征。已经在高达 1 米的采样尺度上广泛研究了天然和人工礁生物群落与结构特征之间的关系。但是，缺乏证据表明，在整个海岸区域环境梯度范围内，量化的局部结构变化对生物群落具有明显的影响。在这里，我们在威尔士的 32 个天然和人工潮间带礁区进行了一项观察性研究，以解决这一知识空白。我们使用多元群落分析和置换检验来研究局部物理结构、区域环境变量和固着生物群落之间的关系。局部生境结构对群落组成的潜在影响在区域尺度环境梯度上是明显的。与天然地点相比，人工礁具有较低的分类丰富度、独特且更多变的群落组成，以及不同的物理结构。在去除生境（天然或人工）的影响后，典范对应分析表明，环境变量（波浪暴露、海面温度和盐度变化）以及两个物理结构指标（对数转换去趋势粗糙度的标准差和表面垂直度的偏度，均在 0.5 米尺度上），解释了 40%的站点间群落组成的变化。这两个结构指标独立解释了 14.5%的变化。个别分类群与环境变量之间的关联表明，具有较高水平表面比例的站点拥有更多的冠层大型藻类，而大型藻类又支持其他藻类和无脊椎动物。我们的研究结果提供了证据，证明可以将结构生态工程干预措施从实验背景下扩展到更大的范围，以提高沿海基础设施的生物多样性。
