Dipartimento di Architettura, Design, Urbanistica, Università di Sassari, Via Piandanna 4, 07100, Sassari, Italy.
MareTerra Onlus-Environmental Research and Conservation, Regione Sa Londra 9, 07041, Alghero, Italy.
Sci Rep. 2021 Sep 13;11(1):18107. doi: 10.1038/s41598-021-97611-x.
Comparing populations across temperature gradients can inform how global warming will impact the structure and function of ecosystems. Shoot density, morphometry and productivity of the seagrass Posidonia oceanica to temperature variation was quantified at eight locations in Sardinia (western Mediterranean Sea) along a natural sea surface temperature (SST) gradient. The locations are spanned for a narrow range of latitude (1.5°), allowing the minimization of the effect of eventual photoperiod variability. Mean SST predicted P. oceanica meadow structure, with increased temperature correlated with higher shoot density, but lower leaf and rhizome width, and rhizome biomass. Chlorophyll a (Chl-a) strongly impacted seagrass traits independent of SST. Disentangling the effects of SST and Chl-a on seagrass meadow shoot density revealed that they work independently, but in the same direction with potential synergism. Space-for-time substitution predicts that global warming will trigger denser seagrass meadows with slender shoots, fewer leaves, and strongly impact seagrass ecosystem. Future investigations should evaluate if global warming will erode the ecosystem services provided by seagrass meadows.
比较不同温度梯度下的种群可以了解全球变暖将如何影响生态系统的结构和功能。在撒丁岛（地中海西部）的八个地点，沿着自然海面温度（SST）梯度量化了海洋草波西多尼亚的芽密度、形态计量学和生产力对温度变化的反应。这些地点的纬度范围很窄（1.5°），可以最大限度地减少光周期变化的影响。平均 SST 预测了 P. oceanica 草甸的结构，随着温度升高，芽密度增加，但叶片和根茎宽度以及根茎生物量降低。叶绿素 a（Chl-a）强烈影响了独立于 SST 的海洋草特征。解分离 SST 和 Chl-a 对海洋草甸芽密度的影响表明，它们独立作用，但方向相同，可能具有协同作用。时空替代预测，全球变暖将引发更密集的海洋草甸，芽细长，叶片较少，对海洋草生态系统产生强烈影响。未来的研究应评估全球变暖是否会侵蚀海洋草甸提供的生态系统服务。
