Cross-Site: Within- and Across-site Variation in Ant Community Structure and Ecosystem Functions at Three Semiarid LTER Sites

这项研究将使用三个LTER站点进行跨站点和站点内的比较，以扩展和丰富我们对这些站点的生物多样性及其动态的知识，并为理解这些生态系统的关键和敏感组成部分的长期动态建立基线。为了回答这个问题，他们将记录地面蚂蚁的物种和群落如何对中原地区(科罗拉多州短草草原)、塞维莱塔地区(草原和奇瓦瓦沙漠之间的过渡带)和乔尔纳达地区(奇瓦瓦沙漠)之间的植被和土地利用的地方和地区梯度做出反应。这项工作侧重于地面蚂蚁，因为它们易于采样和观察，数量丰富，种类多样，具有强烈的行为和竞争相互作用，对小规模和大尺度环境变化都敏感，并可能在干旱和半干旱生态系统的物质移动中发挥重要作用。这些地点代表了温度、降水、植被和生物地理的梯度。在每个地点内，将比较以草为主和灌木为主的植被以及放牧强度不同的地点的蚂蚁群落和功能角色。将利用对巢穴、觅食个体以及从食品站移走种子和粉虫的观察来记录不同功能组蚂蚁产生的物质流动的相对大小如何在一个地点内的不同栖息地之间存在差异，以及这些差异如何受到在区域规模上运行的因素的影响。

This research will employ cross-site and within-site comparisons using three LTER sites to extend and enrich our knowledge of biodiversity and its dynamics at these sites and establish a baseline for understanding the long-term dynamics of a critical and sensitive component of these ecosystems. To answer this question they will document how species and communities of ground-dwelling ants respond to local and regional gradients in vegetation and land-use between the Central Plains site (Colorado shortgrass steppe), the Sevilleta site (transitional between grassland and Chihuahuan Desert), and the Jornada site (Chihuahuan Desert). The work focuses on ground-dwelling ants because they are easily sampled and observed, are abundant and diverse, are characterized by strong behavioral and competitive interactions, are sensitive to both small-scale and large-scale environmental variations, and may play a major role in the movement of materials in arid and semiarid ecosystems. The sites represent a gradient in temperature, precipitation, vegetation, and biogeography. Within each site, ant communities and functional roles will be compared in grass-dominated and shrub- dominated vegetation and in locations differing in grazing intensity. Observations at nest sites of foraging individuals and of removal of seeds and mealworms from food stations will be used to document how the relative magnitude of material flow generated by ants of different functional groups differs among habitats within a site and how these differences are affected by factors operating at the regional scale.