Mediterranean Institute for Agriculture, Environment and Development (MED) University of Évora, Mitra, 7006-554, Évora, Portugal; Conservation Biology Lab (UBC), University of Évora, Mitra, 7002-554, Évora, Portugal.
Research Centre in Geo-Spatial Sciences (CICGE), Faculty of Science, University of Porto, Alameda do Monte da Virgem, 4430-146, Vila Nova de Gaia, Portugal.
J Environ Manage. 2024 Sep;368:122049. doi: 10.1016/j.jenvman.2024.122049. Epub 2024 Aug 11.
Roads are an important source of human economic progress, but also a threat to wildlife populations and natural habitats. Roads are responsible for the direct mortality of hundreds of millions of animals worldwide, with special negative effects for amphibians. Since the middle of the twentieth century, various types of mitigation measures have been constructed to reduce the negative effects of roads. However, despite the large availability of potential solutions designed for this purpose, there is still a knowledge gap about their effectiveness for amphibians. This study analysed whether permanent concrete drift fences reduced the roadkill risk for amphibians. We applied a before-after-control-impact (BACI) design in two road segments with concrete drift fences for amphibians. We recorded amphibians on these road segments three years before and three years after the fence installation. We further tested whether the presence of these mitigation measures transferred the animals to sites adjacent to the drift fences, creating new potential mortality aggregation sites (fence-end effect). Our results show a significant reduction in the number of amphibians reaching the sites with the drift fences. We were, however, unable to demonstrate the potential movement route transference, as our results were inconclusive. Despite the increase in amphibian numbers at the control sites in the first year after fence installation, the following two years presented similar amphibian numbers as the pre-fence years. We recognise the importance of permanent drift fences in reducing the mortality of amphibian populations; however, we encourage future studies to include tunnel-crossing data as well, to truly unveil the roadkill reduction power of amphibian mitigation measures, while maintaining or increasing connectivity between roadside habitats.
道路是人类经济进步的重要来源，但也是野生动物种群和自然栖息地的威胁。道路导致了全世界数以亿计的动物直接死亡，对两栖动物的负面影响尤其严重。自 20 世纪中叶以来，已经建造了各种类型的缓解措施来减少道路的负面影响。然而，尽管有大量为此目的设计的潜在解决方案，但对于两栖动物而言，它们的有效性仍然存在知识差距。本研究分析了永久性混凝土漂移围栏是否降低了两栖动物的道路死亡率。我们在两段带有混凝土漂移围栏的道路段应用了前后对照控制影响（BACI）设计。我们在围栏安装前三年和后三年在这些道路段记录了两栖动物。我们进一步测试了这些缓解措施的存在是否将动物转移到了漂移围栏旁边的地点，从而产生了新的潜在死亡聚集点（围栏端效应）。我们的结果表明，到达漂移围栏地点的两栖动物数量显著减少。然而，我们无法证明潜在的迁移路线转移，因为我们的结果没有定论。尽管在安装围栏后的第一年，对照点的两栖动物数量增加，但随后的两年与围栏前的年份相似。我们认识到永久性漂移围栏在减少两栖动物种群死亡率方面的重要性；然而，我们鼓励未来的研究也包括隧道穿越数据，以真正揭示两栖动物缓解措施减少道路死亡率的能力，同时保持或增加路边栖息地之间的连通性。
