Abstract Habitat disturbance has been found to facilitate the introduction of a wide range of species, including the red imported fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae: Myrmicinae). Despite the link between S. invicta colonization and disturbance, little is known about how different intensities or types of disturbance might impact S. invicta populations. In this study, we used S. invicta populations in cattle pastures to understand how variation in disturbance type and frequency correlates with the density of S. invicta mounds. In total, 56 plots were surveyed for mound abundance during both the wet and dry seasons on a subtropical south Florida ranch. Explanatory variables were grouped into five categories based on disturbance type: 1) historic pasture conversion; 2) modern pasture management (mowing, dragging, chopping, or aerating); 3) grazing intensity (a measure vegetation height and dung pat abundance); 4) distance to human-made and natural localized disturbance (roads, ditches, and wetlands); and 5) abiotic conditions (soil temperature, soil moisture). Overall, the average number of mounds per plot was not significantly different between seasons, but was significantly higher in intensive pastures, which are converted to nonnative forage grasses than in seminative pastures during the dry season.Time since soil disturbance (aeration and chopping of pasture) was a significant predictor of S. invicta densities in both dry and wet seasons, with an increase in time since disturbance being associated with higher mound densities. Other forms of pasture management that did not disturb the soil, such as dragging and mowing, as well as distance to localized disturbances (wetlands, roads, and ditches) were not found to have a significant correlation in either season.

中文翻译：

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佛罗里达州中部牧场红火蚁Solenopsis invicta（膜翅目：蚁科）的分布

摘要 栖息地干扰已被发现有助于引入多种物种，包括红色进口火蚁 Solenopsis invicta Buren（膜翅目：蚁科：Myrmicinae）。尽管 S. invicta 定植和干扰之间存在联系，但人们对不同强度或类型的干扰如何影响 S. invicta 种群知之甚少。在这项研究中，我们使用牛牧场中的 S. invicta 种群来了解干扰类型和频率的变化如何与 S. invicta 丘的密度相关。总共对 56 个地块进行了调查，以确定在南佛罗里达州亚热带牧场的雨季和旱季期间的土丘丰度。解释变量根据干扰类型分为五类：1）历史牧场转换；2）现代牧场管理（割、拖、砍、或充气）；3) 放牧强度（衡量植被高度和粪便丰度）；4）与人为和自然局部干扰（道路、沟渠和湿地）的距离；5) 非生物条件（土壤温度、土壤湿度）。总体而言，每个地块的平均土墩数在季节之间没有显着差异，但在旱季转化为非天然牧草的集约型牧场显着高于精育牧场。 自土壤扰动（牧场通气和砍伐）以来的时间) 是干季和湿季 S. invicta 密度的重要预测因子，随着干扰与更高的土墩密度相关，时间增加。其他不干扰土壤的牧场管理形式，例如拖曳和割草，