Abstract Although agrochemicals and solar ultraviolet (UV) radiation are both environmental stressors currently associated with amphibian decline, little is known about their interactive effects on amphibian larvae. One potential hazardous consequence of this interaction could be the increase of chromosomal damage and induction of cell death, which culminate in tadpole mortality. In this study, the preservation level of the riparian forest of four different streams located at the Atlantic Forest in southern Brazil was evaluated through satellite imagery analysis. The incidence of solar UVB and UVA radiation were measured with a radiometer in the amphibian breeding sites, and the presence of agrochemicals in the water was quantified through liquid chromatography coupled in tandem to mass spectrometry. Tadpole population density of two endangered forest-specialist amphibian species (Boana curupi and Crossodactylus schmidti) was evaluated in each stream, and the chromosomal damage of the collected larvae was determined through cytogenetic analysis of blood samples. The results clearly indicate that the preservation of riparian forest efficiently blocks the incidence of UV radiation upon the water surface and reduce by 2.7-fold the entry of agrochemicals from adjacent agricultural crops. Tadpoles collected in streams with preserved and continuous riparian forest presented a significantly lower amount of micronuclei, as well as higher population density in comparison to tadpoles collected in streams located in converted agricultural landscape. Therefore, this study demonstrates that the preservation of the riparian forest has paramount importance in reducing the impact of environmental genotoxic agents into lotic breeding sites used by forest-specialist amphibian species.

中文翻译：

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受保护的河岸森林保护濒临灭绝的森林专家两栖动物免受阳光和农用化学品的遗传毒性影响

摘要 尽管农用化学品和太阳紫外线 (UV) 辐射都是目前与两栖动物衰退相关的环境压力因素，但它们对两栖动物幼虫的相互作用知之甚少。这种相互作用的一个潜在危险后果可能是染色体损伤的增加和细胞死亡的诱导，最终导致蝌蚪死亡。在这项研究中，通过卫星图像分析评估了位于巴西南部大西洋森林的四个不同溪流的河岸森林的保存水平。在两栖动物繁殖地使用辐射计测量太阳 UVB 和 UVA 辐射的发生率，并通过液相色谱串联质谱法量化水中农用化学品的存在。在每个溪流中评估了两种濒临灭绝的森林专业两栖动物（Boana curupi 和 Crossodactylus schmidti）的蝌蚪种群密度，并通过血液样本的细胞遗传学分析确定了收集的幼虫的染色体损伤。结果清楚地表明，河岸森林的保护有效地阻止了紫外线辐射对水面的影响，并将来自邻近农作物的农用化学品的进入减少了 2.7 倍。与在改建的农业景观中的溪流中收集的蝌蚪相比，在具有保存完好且连续的河岸森林的溪流中收集的蝌蚪具有显着较低的微核量，以及更高的种群密度。所以，