Artificial shorelines lack natural structural complexity across scales (dataset)

From microbes to humans, habitat structural complexity plays a direct role in the provision of physical living space and increased complexity supports higher biodiversity and ecosystem functioning across biomes. Natural coastlines are structurally complex transition zones between land and sea that support diverse ecological communities but are under increasing pressure from human activity. Coastal development and the construction of artificial shorelines are changing our landscape and altering biodiversity patterns as humans seek both socio-economic benefits and protection from coastal storms, flooding, and erosion. In this study, we evaluate how much structural complexity is missing, and at which scales, with the creation of artificial structures compared to naturally occurring rocky shores. We quantified the structural complexity of both artificial and natural shores at resolutions from 1 mm through to 10s of m using three remote sensing platforms (handheld camera, terrestrial laser scanner and uncrewed aerial vehicles) across both artificial and natural shorelines. Natural shorelines were approximately 20-50 % more structurally complex and offered greater structural variation between locations. In contrast, artificial shorelines were more structurally homogenous and typically deficient in structural complexity across scales. Our findings reinforce concerns that replacing natural rocky shorelines with artificial structures simplifies coastlines at organism-relevant scales. Furthermore, we offer much-needed insight into how structures might be modified to more closely capture the complexity of natural shorelines that support biodiversity.

从微生物到人类，生境结构复杂度均直接影响物理生存空间的供给；生境复杂度的提升，在各类生物群区（biome）中均有助于维持更高的生物多样性与生态系统功能。自然海岸线是连接陆地与海洋的结构复杂过渡带，支撑着多样的生态群落，却正面临日益加剧的人类活动压力。为获取社会经济效益并抵御海岸风暴、洪涝与海岸侵蚀，人类开展海岸开发与人工岸线建设，这一过程正改变着海岸景观格局，并干扰生物多样性分布模式。本研究以天然岩质海岸为参照，对比人工岸线与天然岸线的结构差异，量化评估人工岸线相较于天然岸线所缺失的结构复杂度及其发生的空间尺度。本研究采用三种遥感平台（手持相机、地面激光扫描仪（terrestrial laser scanner）、无人飞行器（uncrewed aerial vehicles）），在1毫米至数十米的多分辨率尺度下，对人工与天然岸线的结构复杂度进行了系统性量化分析。研究结果显示，天然岸线的结构复杂度平均高出20%至50%，且不同采样位点间的结构异质性更强；相较之下，人工岸线的结构均一性更强，且在全空间尺度下普遍存在结构复杂度缺失的问题。本研究结果进一步印证了此前的学术担忧：以人工构筑物替代天然岩质海岸，会在与生物生存密切相关的空间尺度上简化海岸生态系统结构。此外，本研究还为如何优化人工岸线结构，使其更贴近支撑生物多样性的天然岸线复杂度提供了亟需的理论参考与实践指引。