School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth, Devon, PL4 8AA, UK.
School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth, Devon, PL4 8AA, UK.
Environ Pollut. 2024 Nov 1;360:124573. doi: 10.1016/j.envpol.2024.124573. Epub 2024 Jul 17.
Coastal ecosystems face a multitude of pressures including plastic pollution and increased flood risk due to sea level rise and the frequency and severity of storms. Experiments seldom examine multiple stressors such as these, but here we quantified the effect of microplastics (polyethylene terephthalate (PET): a durable plastic and polybutylene adipate terephthalate (PBAT): a biodegradable polymer), in combination with simulated seawater inundation on the coastal species Plantago coronopus. After 35-days exposure to plastic (0.02 g.Kg, <300 μm diameter), P. coronopus were flooded to pot height with artificial seawater for 72-h, drained and grown for a further 24-days. Plant mortality, necrosis and photosynthetic efficiency (F/F) were recorded throughout, with root:shoot biomass and scape production (flower stalks) quantified at harvest. There were significant interactions between microplastics and seawater on the root:shoot ratio; a measure of resource allocation. The allocation to belowground biomass increased significantly under the PET + inundation treatment compared to the PBAT + inundation and the no plastic + inundation treatments, with potential consequences on the capture of water, nutrients and sunlight, which can affect plant performance. Plant necrosis significantly increased, and F/F declined as a result of seawater inundation. While not significant, plant F/F responses were influenced by microplastics (17% and 7% reduction in PBAT and PET exposure respectively compared to the no plastic control). Plants mediated this stress response with no discernible treatment-specific effects detected in F/F 14-days after seawater introduction. Plastic exposure significantly influenced potential reproductive output, with lower average scape numbers across PBAT treatments, but higher in PET treatments. This study highlights the complex interactions and potential for microplastics to present an elevated risk when in combination with additional stressors like seawater flooding; establishing the threat presented to ecosystem resilience in a changing world is a priority.
沿海生态系统面临着多种压力，包括塑料污染以及海平面上升、风暴的频率和强度增加导致的洪水风险。实验很少同时检测这些多种压力源，但在这里，我们量化了微塑料（聚对苯二甲酸乙二醇酯（PET）：一种耐用塑料和聚对苯二甲酸丁二醇酯（PBAT）：一种可生物降解聚合物）与模拟海水淹没相结合对沿海物种车前草的影响。在暴露于塑料（0.02 g.Kg，<300μm 直径）35 天后，将 P. coronopus 用人工海水淹没到盆高 72 小时，排水并再生长 24 天。在整个过程中记录植物死亡率、坏死和光合作用效率（F/F），收获时量化根：茎生物量和花序（花梗）产量。微塑料和海水对根：茎比（资源分配的衡量标准）有显著的相互作用。与 PBAT 淹没和无塑料淹没处理相比，PET 淹没处理下地下生物量的分配显著增加，这可能对水、养分和阳光的捕获产生影响，从而影响植物的性能。由于海水淹没，植物坏死显著增加，F/F 下降。虽然不显著，但微塑料对植物 F/F 反应有影响（与无塑料对照相比，暴露于 PBAT 和 PET 时分别减少 17%和 7%）。植物通过这种应激反应进行调节，但在海水引入后 14 天没有检测到可识别的特定处理效应。塑料暴露显著影响潜在的生殖产量，PBAT 处理的平均花序数量较低，但 PET 处理的花序数量较高。本研究强调了微塑料与其他压力源（如海水淹没）结合时存在的复杂相互作用和潜在风险，确定在不断变化的世界中对生态系统恢复力构成的威胁是当务之急。
