Data from: Exploring the effects of salinization on trophic diversity in freshwater ecosystems: a quantitative review

Salinization of freshwater ecosystems represents a potential threat to biodiversity, but the distribution of salinity tolerance among freshwater organisms and its functional consequences are understudied. In this study, we reviewed global patterns of salinity tolerance across a broad range of freshwater organisms. Specifically, we compared published data on LC50 (a metric of salinity tolerance) across climatic regions, taxa, and functional feeding groups (FFGs). We found that microinvertebrates were more sensitive to salinity than vertebrates and macroinvertebrates. Within aquatic insects, there was considerable variability in tolerance across FFGs. Specifically, scrapers, gatherers, and filterers were more sensitive on average than omnivores, shredders, and predators. Thus, we predict that increasing salinization can negatively impact trophic diversity and in turn cause overall changes in the structure and function of freshwater ecosystems. We also identified both historical exposure and taxonomic affinity as potential drivers of contemporary salinity tolerance across freshwater organisms. Finally, we found important gaps in our understanding of the potential impacts of salinization on freshwater biodiversity, particularly in regions expected to be affected by increased salinization due to climate change and secondary salinization. Understanding the differential vulnerability of freshwater taxa is critical to predicting the ecosystem impacts of salinization, and informing conservation and management decisions.

淡水生态系统盐渍化对生物多样性构成潜在威胁，但目前针对淡水生物的盐耐受度分布及其生态功能影响的研究仍较为匮乏。本研究针对各类淡水生物的盐耐受度全球分布模式展开综述。具体而言，我们对比了已发表的半致死浓度（LC50，盐耐受度衡量指标）数据，分析其在不同气候区、生物类群及功能摄食类群（Functional Feeding Groups, FFGs）间的差异。研究发现，微型无脊椎动物对盐度的敏感性高于脊椎动物与大型无脊椎动物。在水生昆虫中，不同功能摄食类群的盐耐受度存在显著差异：刮食者、收集者与滤食者的平均敏感性显著高于杂食者、撕食者及捕食者。据此我们推测，盐度持续升高将对营养多样性产生负面影响，进而引发淡水生态系统结构与功能的整体改变。此外，我们发现历史盐暴露与类群亲缘关系均可作为淡水生物当代盐耐受度的潜在驱动因素。最后，我们发现当前对盐渍化对淡水生物多样性的潜在影响认知仍存在重要空白，尤其是在因气候变化与次生盐渍化而面临盐度升高风险的区域。明确淡水生物类群的差异化脆弱性，对于预测盐渍化的生态系统影响、为保护与管理决策提供依据至关重要。