1. Leaf-cutting ants (LCA) frequently show positive associations with human disturbance in forest biome, explained by habitat opening and increase of pioneer vegetation. However, little is known about LCA response in grassland biome. Agriculture and commercial forestry typically introduce closed habitats and displace pioneer vegetation when occurring in grasslands. The aim of this study was to assess the response of LCA to different land use types developed in a grassland biome.
2. Semi-natural grassland remnants, soybean crops, cattle pastures and young and mature eucalypt plantations were sampled in Entre Ríos, Argentina. LCA nest abundance and occurrence of workers was obtained by hand sampling and baited pitfall traps.
3. LCA nest abundance significantly decreased in most land use types when compared with the grassland sites. All habitat types were characterized by the presence of different LCA species, which showed different associations with temperature, vegetation and soil structure.
4. Our results suggest that LCA response to human disturbance depends on the biome where it occurs; contrary to what was observed in forests, the LCA assemblage was negatively associated to human disturbance in grasslands. The response of the whole assemblage masked different responses of LCA species, possibly indicating differences in their ecological niche.

中文翻译：

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草地生物群落不同农作方式下切叶蚁的丰度及分布

1. 切叶蚁 (LCA) 经常与森林生物群落中的人类干扰呈正相关，这可以通过栖息地开放和先锋植被的增加来解释。然而，人们对草原生物群落中的 LCA 反应知之甚少。当发生在草原上时，农业和商业林业通常会引入封闭的栖息地并取代原始植被。本研究的目的是评估 LCA 对草地生物群落中开发的不同土地利用类型的响应。
2. 在阿根廷恩特雷里奥斯 (Entre Ríos) 采样了半天然草原残余物、大豆作物、牛牧场以及年轻和成熟的桉树种植园。LCA 巢的丰度和工人的出现是通过手工采样和诱饵陷阱陷阱获得的。
3. 与草地相比，大多数土地利用类型的 LCA 巢丰度显着降低。所有栖息地类型的特点是存在不同的 LCA 物种，这与温度、植被和土壤结构显示出不同的关联。
4. 我们的结果表明 LCA 对人类干扰的反应取决于它发生的生物群落；与在森林中观察到的相反，LCA 组合与草原中的人类干扰呈负相关。整个组合的反应掩盖了 LCA 物种的不同反应，可能表明它们的生态位存在差异。