Venice Lagoon (Italy), the largest wetland in the Mediterranean basin, is extremely vulnerable to variations in relative sea level (RSL) which is locally defined by an average rising rate of about 2.5mm per year, resulting from both sea-level change and vertical land movements. The environmental pressures stemming from projected higher RSL rising rates will have a profound impact on Venetian coastal ecosystems with a significant loss of wetlands partly due to a drastic reduction of salt marsh habitats. To understand how changes in marine influence could create such ecological upheaval in the near future, and fully remodel these coastal salt marshes, we reconstructed 5650 years of RSL rise history and land subsidence impacts on ecosystem dynamics during the Holocene transgression of Venice Lagoon. We show that the evolution of ecosystems mainly mirrors the gradual intrusion of salt water that progressively reshaped the coastal vegetation by turning the area into salt lagoon habitats. Before marine influence became dominant, the area was mainly fed by substantial freshwater supplies allowing the development of a diversified alluvial vegetation. Environmental pressures increased markedly about 6800–6600 years ago when seawater began to significantly influence the area, affecting marsh-swamp ecosystems. These marine inputs promoted the spread of halophytic and salt-tolerant vegetation types which laid the foundations for what would become the current salt marsh habitats. Venice Lagoon serves as a stark reminder of how rising sea levels, accompanied by increased saltwater intrusion into freshwater habitats and adjacent lands, can drastically alter and reshape pre-existing ecosystems. The lagoon's long-term ecological record indicates that contemporary fluctuations in RSL pose a substantial ecological threat, potentially culminating in a major upheaval of aquatic habitats in the near future.

中文翻译：

---

全新世海平面对威尼斯泻湖沿海湿地的影响

威尼斯泻湖（意大利）是地中海盆地最大的湿地，极易受到相对海平面 (RSL) 变化的影响，相对海平面 (RSL) 的局部定义为每年平均上升约 2.5 毫米，这是由于海平面变化和垂直地面运动。预计 RSL 上升率上升所带来的环境压力将对威尼斯沿海生态系统产生深远影响，湿地大量丧失，部分原因是盐沼栖息地急剧减少。为了了解海洋影响的变化如何在不久的将来造成这样的生态剧变，并全面重塑这些沿海盐沼，我们重建了威尼斯泻湖全新世海侵期间 5650 年的 RSL 上升历史和地面沉降对生态系统动态的影响。我们表明，生态系统的演变主要反映了咸水的逐渐入侵，咸水通过将该地区变成盐湖栖息地而逐渐重塑了沿海植被。在海洋影响占主导地位之前，该地区主要依靠大量淡水供应，从而发展了多样化的冲积植被。大约 6800-6600 年前，当海水开始对该地区产生重大影响，影响沼泽生态系统时，环境压力显着增加。这些海洋输入促进了盐生和耐盐植被类型的传播，为目前的盐沼栖息地奠定了基础。威尼斯泻湖清楚地提醒人们，海平面上升，加上海水对淡水栖息地和邻近土地的入侵增加，可能会极大地改变和重塑现有的生态系统。泻湖的长期生态记录表明，RSL 的当代波动构成了巨大的生态威胁，可能最终导致在不久的将来水生栖息地发生重大剧变。