Gaytán Álvaro, Canelo Tara, Pérez-Izquierdo Carlos, Bonal Raúl
Institute of Natural Resources and Agrobiology of Seville (IRNAS-CSIC), Seville, Spain.
Departamento de Ingeniería del Medio Agronómico y Forestal, Grupo de Investigación Forestal, INDEHESA, Universidad de Extremadura, Plasencia, Spain.
Ecol Appl. 2025 Jan;35(1):e3088. doi: 10.1002/eap.3088.
Livestock grazing and trampling have been shown to reduce arthropod populations. Among arthropods, defoliating lepidopterans are particularly important for their impact on trees, the keystone structures of agroforestry systems. This study investigates the impact of livestock on the community of defoliating lepidopterans in agroforestry systems. We conducted both experimental and observational studies in the mid-west and western regions of the Iberian Peninsula. In our field experiment, we sampled lepidopteran caterpillars in areas with livestock and in areas where livestock had been excluded for short and long periods. To validate our experimental results, we conducted a field survey across seven areas with and without livestock in the western Iberian Peninsula. Our findings revealed that after 2 years from the start of the experiment, the exclusion of livestock led to an increase in the abundance and species richness of lepidopterans, as well as shifts in their community composition. Our experimental findings were corroborated by our field survey. Interestingly, we found that the differences in community composition among exclusions were primarily due to species nestedness. Livestock exclusion consistently favored species that pupate in the ground, suggesting that livestock can alter the lepidopteran community by predating or accidentally trampling these species. This study underscores the significant role livestock play in modifying the community of defoliating lepidopterans in Mediterranean agroforestry systems (oak savannahs), with important implications for food webs and species interactions.
牲畜放牧和践踏已被证明会减少节肢动物种群数量。在节肢动物中，食叶鳞翅目昆虫因其对树木（农林复合系统的关键结构）的影响而尤为重要。本研究调查了牲畜对农林复合系统中食叶鳞翅目昆虫群落的影响。我们在伊比利亚半岛的中西部和西部地区进行了实验研究和观察研究。在我们的田间实验中，我们在有牲畜的区域以及牲畜被排除不同时长的区域对鳞翅目幼虫进行了采样。为了验证我们的实验结果，我们在伊比利亚半岛西部七个有牲畜和无牲畜的区域进行了实地调查。我们的研究结果表明，从实验开始2年后，排除牲畜导致鳞翅目昆虫的丰度和物种丰富度增加，以及它们的群落组成发生变化。我们的实地调查证实了我们的实验结果。有趣的是，我们发现排除区域之间群落组成的差异主要归因于物种嵌套。排除牲畜始终有利于在地面化蛹的物种，这表明牲畜可以通过捕食或意外践踏这些物种来改变鳞翅目昆虫群落。这项研究强调了牲畜在地中海农林复合系统（橡树林地）中对食叶鳞翅目昆虫群落的显著影响，这对食物网和物种相互作用具有重要意义。
