RAPID: Ant community responses to a 1000-year flooding event

在全球环境变化的影响下，灾难性的火灾或洪水等极端天气事件预计将变得更加可能。科学家对这种极端事件如何影响植物和动物的丰富程度，包括影响人类福祉的物种，如传粉媒介或入侵害虫，了解相对较少。提高这种科学认识需要我们从自然灾害中吸取教训。该项目研究了2017年8月与飓风哈维相关的极端洪水如何影响德克萨斯州东部大灌木丛地区蚂蚁的丰度和群落组成。这个地区有几十种本地蚂蚁，它们提供有价值的生态系统服务，比如分解和害虫控制，以及有害的入侵物种（火蚁和茶色疯狂蚂蚁）。研究人员将使用“之前”和“之后”的样本来验证飓风哈维破坏了东德克萨斯州蚂蚁群落的假设，有利于入侵蚂蚁的数量和范围的增加。这项研究将与国家公园管理局合作进行，他们希望更多地了解飓风哈维对生态的影响。科学家们将把他们的结果传达给德克萨斯州休斯顿和博蒙特社区的公众，这两个社区受到火蚁的影响，并受到哈维洪水的强烈影响。生态学理论认为，群落中物种的相对丰度甚至存在可能是由与罕见事件相关的历史偶然事件驱动的，就像从平均环境条件中过滤出来一样。对21世纪环境变化的预测包括极端事件的频率增加，生态学家越来越多地被要求预测其后果。研究人员将研究与哈维飓风相关的1000年洪水如何改变大灌木丛蚂蚁群落的分类和功能特征组成。研究人员将利用三年的事前抽样来对比哈维洪水前后蚂蚁群落的丰度、多样性和物种组成。重要的是，事前工作表明外来蚂蚁物种已经开始渗透到完整的本地群落中。研究人员将评估飓风哈维是否增加了外来蚂蚁入侵的机会。他们将每月在19个已建立的地点进行陷阱取样，以记录蚂蚁群落的变化，并测试对飓风的反应是短暂的还是代表新的稳定状态。他们还将为这些群落建立一个功能特征数据库，以测试分类变化是否由赋予洪水耐受性的物种特异性特征的过滤所驱动。感兴趣的功能特征包括风险扩散策略，如一夫多妻制（每个群体有多个女王）和一夫多妻制（多个筑巢地点）。由于研究区域的洪水刚刚退去，研究生态响应和恢复的动态是一个紧迫的机会窗口。

Extreme weather events, such as catastrophic fires or floods, are expected to become more likely under global environmental change. Scientists have a relatively poor understanding of how such extreme events influence the abundance of plants and animals, including species that affect human well-being such as pollinators or invasive pests. Improving this scientific understanding requires that we learn from natural disasters. This project examines how extreme flooding associated with Hurricane Harvey in August 2017 affected the abundance and community composition of ants in the Big Thicket region of east Texas. This region hosts dozens of native ant species that provide valuable ecosystem services, such as decomposition and pest control, as well as noxious invasive species (fire ants and tawny crazy ants). The researchers will use "before" and "after" samples to test the hypothesis that Hurricane Harvey disrupted east Texas ant communities, favoring an increase in abundance and extent of invasive ants. The research will be conducted in coordination with the National Park Service, who hope to learn more about the ecological effects of Hurricane Harvey. The scientists will communicate their results to the public in the Texas communities of Houston and Beaumont, which were affected by fire ants and strongly affected by Harvey's floodwaters.Ecological theory suggests that the relative abundance and even presence of species in communities may be driven as much by historical contingencies associated with rare events as by filtering from average environmental conditions. Forecasts for environmental change in the 21st century include an increase in frequency of extreme events, and ecologists are increasingly called upon to predict their consequences. The researchers will study how the 1,000-year flooding associated with Hurricane Harvey modified the taxonomic and functional trait composition of Big Thicket ant communities. The researchers will leverage three years of pre-event sampling to contrast the abundance, diversity, and species composition of ant communities before and after Harvey's floodwaters. Importantly, pre-event work demonstrated that exotic ant species had begun to penetrate the intact native communities. The researchers will evaluate whether Hurricane Harvey increased opportunities for invasion by exotic ants. They will conduct monthly pitfall sampling at 19 established sites to document changes in ant communities, and test whether changes in response to the hurricane are transient or represent new stable states. They will also assemble a functional trait database for these communities to test whether taxonomic shifts were driven by the filtering of species-specific traits that confer tolerance to flooding. Functional traits of interest include risk-spreading strategies such as polygyny (multiple queens per colony) and polydomy (multiple nesting locations). As the floodwaters have just now receded in the study area, there is an urgent window of opportunity to study the dynamics of ecological response and recovery.