水生植物烷基脂类含量，丰度及其单体δD变化数据集（2019）

水生植物是湖泊沉积物中原生有机质的主要输入源，但目前对水生植物脂肪酸（FA）和正构烷烃分布的研究有限，极大地阻碍了其同位素地球化学在湖泊环境中的应用。在此，利用国际上已报道的湖泊水生植物正烷基脂质分布，结合中国湖泊（云南和内蒙古）新近获得的水生植物正烷基脂质数据，来了解其分布特征。结果表明，水生植物主要含有中链脂质（C23-C25正构烷烃和C22-C24 FAs），不同于陆生植物（以长链脂质为主），但长链正构烷烃（如C27和C29）与长链FAs（如C26和C28）在大多数样品中也表现出高丰度。沉水植物具有高浓度的长链正构烷烃（平均47 μg g-1）和长链FAs（平均170 μg g-1），与陆生植物相近，说明沉水植物可能对湖泊沉积物中的长链正烷基脂质有较大贡献，而藻类衍生的长链正烷基脂质对湖泊沉积物的贡献可能很小，因为它们的浓度较低（正构烷烃平均浓度为2 μg g-1，FAs为9 μg g-1）。我们发现脂质分子指标（包括ACL14-32和ATR14-18）可以可靠地区分来源于藻类和其他植物的FAs，Paq′值可以用来区分沉水植物和陆生植物之间的正构烷烃来源。对于每个样品，水生植物在不同链长的正构烷烃和FAs之间没有显著的δD差异，说明湖泊沉积物中不同链长的正烷基脂质的δD值之间的偏移有助于确定沉积脂类的输入来源并推断古水文变化。
数据实体包括：
1) 云南和内蒙古不同藻类、沉水植物和陆生植物样品中正构烷烃和FA δD值
2) 云南和内蒙古不同藻类、沉水植物和陆生植物样品中正构烷烃（C21-C33）的含量（ng g-1）
3) 云南和内蒙古不同藻类、沉水植物和陆生植物样品中脂肪酸（C14-C32）浓度（ng g-1）

Aquatic macrophytes are the primary source of primary organic matter input to lacustrine sediments, yet current studies on the distribution of fatty acids (FAs) and n-alkanes in aquatic macrophytes remain limited, which greatly hinders the application of their isotopic geochemistry in lacustrine environments.
Here, we compile published distributions of n-alkyl lipids from lacustrine aquatic macrophytes worldwide and newly acquired n-alkyl lipid data from aquatic macrophytes in lakes of Yunnan and Inner Mongolia, China, to characterize their distribution patterns.
The results show that aquatic macrophytes are dominated by medium-chain n-alkyl lipids (C23-C25 n-alkanes and C22-C24 FAs), which differs from terrestrial plants that are characterized by long-chain n-alkyl lipids. However, long-chain n-alkanes (e.g., C27 and C29) and long-chain FAs (e.g., C26 and C28) also exhibit high abundances in most samples.
Submerged macrophytes have high concentrations of long-chain n-alkanes (average 47 μg g⁻¹) and long-chain FAs (average 170 μg g⁻¹), which are comparable to those of terrestrial plants. This indicates that submerged macrophytes may make a substantial contribution to long-chain n-alkyl lipids in lacustrine sediments, while the contribution of algal-derived long-chain n-alkyl lipids to lacustrine sediments is likely minimal, as their concentrations are low (average 2 μg g⁻¹ for n-alkanes and 9 μg g⁻¹ for FAs).
We find that lipid molecular indices (including ACL₁₄₋₃₂ and ATR₁₄₋₁₈) can reliably distinguish FAs derived from algae and other plants, while the Paq′ index can be used to differentiate the sources of n-alkanes between submerged macrophytes and terrestrial plants.
For each sample, aquatic macrophytes show no significant δD differences among n-alkanes and FAs of different chain lengths. This suggests that the offsets in δD values of n-alkyl lipids with varying chain lengths in lacustrine sediments can help identify the input sources of sedimentary lipids and reconstruct paleohydrological changes.

The dataset includes:
1) δD values of n-alkanes and FAs in samples of algae, submerged macrophytes and terrestrial plants from lakes in Yunnan and Inner Mongolia
2) Concentrations (ng g⁻¹) of n-alkanes (C21-C33) in samples of algae, submerged macrophytes and terrestrial plants from lakes in Yunnan and Inner Mongolia
3) Concentrations (ng g⁻¹) of fatty acids (C14-C32) in samples of algae, submerged macrophytes and terrestrial plants from lakes in Yunnan and Inner Mongolia