Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

[摘要] Coralline algae are important habitat formers found on all rocky shores.While the impact of future ocean acidification on the physiologicalperformance of the species has been well studied, little research hasfocused on potential changes in structural integrity in response to climatechange. A previous study using 2-D Finite Element Analysis (FEA) suggestedincreased vulnerability to fracture (by wave action or boring) in algaegrown under high CO₂ conditions. To assess how realistically 2-Dsimplified models represent structural performance, a series of increasinglybiologically accurate 3-D FE models that represent different aspects ofcoralline algal growth were developed. Simplified geometric 3-D models of thegenus Lithothamnion were compared to models created from computed tomography (CT) scandata of the same genus. The biologically accurate model and the simplifiedgeometric model representing individual cells had similar average stressesand stress distributions, emphasising the importance of the cell walls indissipating the stress throughout the structure. In contrast models withoutthe accurate representation of the cell geometry resulted in larger stressand strain results. Our more complex 3-D model reiterated the potential ofclimate change to diminish the structural integrity of the organism. Thissuggests that under future environmental conditions the weakening of thecoralline algal skeleton along with increased external pressures (wave andbioerosion) may negatively influence the ability for coralline algae tomaintain a habitat able to sustain high levels of biodiversity.

[学科分类] 地球化学与岩石