Data related to: Bottom-up effects of fungicides on tadpoles of the European common frog (Rana temporaria)

We have uploaded a range of files informding about ergosterol and bacteria levels on leaf litter (LeafMicrobes.xlsx); the feces production, leaf consumption and legnth development of tadpoles during the study and among the two experimental phases as detailed in the mansucript (FecesFeedingLength.xlxs); composition of fatty acids in tadpoles and leaf litter (NFLA.xlxs); metamophoses event (Metamorphosis.xlsx) Paper abstract as submitted: Biodiversity is under pressure world-wide, with amphibians being particularly threatened. Stressors related to human activity, such as chemicals, are contributing to this decline. It remains, however, unclear whether chemicals exhibiting a fungicidal activity could indirectly affect tadpoles, that depend on microbially conditioned leaf litter as food source. The indirect effect of fungicides (sum concentration of a fungicide mixture composed of azoxystrobin, carbendazim, crybrodinil, quinoxifen and tebuconcazole: 100 µg/L) on tadpoles was assessed relative to leaf litter colonised by microbes in absence of fungicides (control) and a worst case scenario, that is leached leaf litter without microbial colonisation. The quality of leaf litter as food for tadpoles of the European common frog (Rana temporaria) was characterised through neutral lipid fatty acid profiles and microbial sum parameters and verified by sublethal responses in tadpoles (i.e. feeding rate, feces production, growth and fatty acid composition). Fungicides changed the nutritious quality of leaf litter likely through alterations in leaves' neutral lipid fatty acid profiles (i.e., changes in some physiologically important highly unsaturated fatty acids reached more than 200%) in combination with a potential adsorption onto leaves during conditioning. These changes were reflected by differences in the development of tadpoles ultimately resulting in an earlier start of metamorphosis. Our data provide a first indication that fungicides potentially affect tadpole development indirectly through bottom-up effects. This pathway is so far not addressed in fungicide environmental risk assessment and merits further attention.

我们已上传一系列数据集文件，具体包括：关于枯落叶上麦角固醇（ergosterol）与细菌水平的数据集（LeafMicrobes.xlsx）；本研究两个实验阶段内蝌蚪粪便产生量、叶片摄食量及体长发育情况的数据集（FecesFeedingLength.xlxs，相关细节已在论文手稿中详述）；蝌蚪与枯落叶的脂肪酸组成数据集（NFLA.xlxs）；以及变态事件记录数据集（Metamorphosis.xlsx）。

本研究提交的论文摘要如下：全球生物多样性正承受严峻压力，两栖动物受威胁程度尤为突出。人类活动带来的各类胁迫因子（如化学品）正加速这一衰退进程，但目前仍不清楚具有杀真菌活性的化学品是否会通过间接途径对蝌蚪造成影响——蝌蚪依赖经微生物定殖的枯落叶作为食物来源。

本研究设置了两组对照：其一为无杀真菌剂条件下经微生物定殖的枯落叶对照组，其二为未经过微生物定殖的沥滤枯落叶最坏场景组，以此评估由嘧菌酯、多菌灵、咯菌腈、喹氧灵和戊唑醇复配而成的杀真菌剂混合物（总浓度100 µg/L）对蝌蚪的间接影响。

研究通过中性脂质脂肪酸谱与微生物总量参数，对欧洲林蛙（Rana temporaria）蝌蚪的食物——枯落叶的营养品质进行了表征，并通过蝌蚪的亚致死响应指标（摄食率、粪便产生量、生长状况与脂肪酸组成）验证了该营养品质。

结果显示，杀真菌剂可能通过改变叶片的中性脂质脂肪酸谱（部分生理重要的高度不饱和脂肪酸变化幅度超过200%），并结合定殖过程中可能在叶片表面的吸附作用，改变枯落叶的营养品质。此类变化最终体现在蝌蚪的发育差异中，导致变态启动时间提前。

本研究数据首次表明，杀真菌剂可能通过上行效应（bottom-up effects）间接影响蝌蚪发育。目前杀真菌剂的环境风险评估尚未涉及这一作用途径，该研究方向值得进一步关注。