Disturbance shapes ecological communities. Frequency, predictability, and intensity characterize disturbances, which select for resistant and/or resilient traits of species. Unpredictable and infrequent disturbance events, especially those with no reliable cues, lack selection strength and have less calculable effects on species assemblages and trait-based species sorting. In a flood plain in Northeast Costa Rica, across sites with varying flood frequency and no reliable cues to signal flooding, we used ants as a focal taxon to assess the impact of disturbance on ant activity and species assemblage. We examined activity patterns such as extent of occupancy of baits and nesting guild (i.e. strata used) that might mediate the effects of stochastic flood events. We hypothesized that the ant community in the most frequently flooded site would be dominated by above-ground nesting ants whose nesting traits make them resilient to inundation. The site with the most frequent flooding had the lowest level of ant presence on baits and differed in species assemblage, as demonstrated by the analysis of similarity, compared with the sites with lower flooding frequency. Neither overall species richness nor richness of species in the above-ground nesting guild differed between sites. However, nesting in trees above flood waters may be beneficial to escape frequent and unreliable flooding of habitats, and, as we hypothesized, there was greater activity of above-ground nesting ants compared with ground nesting ants in the most frequently flooded site. These differences in nesting guilds were diminished in the drier sites.

中文翻译：

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蚂蚁活动和筑巢生态的模式取决于新热带洪泛区的洪水强度

干扰塑造生态群落。频率、可预测性和强度表征干扰，选择物种的抗性和/或弹性特性。不可预测和罕见的干扰事件，尤其是那些没有可靠线索的干扰事件，缺乏选择强度，对物种组合和基于性状的物种分类的影响较小。在哥斯达黎加东北部的一个洪泛平原，跨越洪水频率不同且没有可靠的洪水信号线索的地点，我们使用蚂蚁作为焦点分类群来评估干扰对蚂蚁活动和物种组合的影响。我们检查了活动模式，例如可能调节随机洪水事件影响的诱饵和筑巢行会（即使用的地层）的占用程度。我们假设，在最常被洪水淹没的地点，蚂蚁群落将由地上筑巢的蚂蚁占据主导地位，这些蚂蚁的筑巢特征使它们能够抵御洪水。与洪水频率较低的地点相比，洪水最频繁的地点在诱饵上的蚂蚁含量最低，物种组合也不同，如相似性分析所示。地面筑巢行会的整体物种丰富度和物种丰富度在不同地点之间均无差异。然而，在洪水上方的树木中筑巢可能有利于避免栖息地频繁和不可靠的洪水，而且，正如我们假设的那样，与最常被洪水淹没的地点的地面筑巢蚂蚁相比，地上筑巢蚂蚁的活动更大。