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

本研究将利用三个LTER站点进行跨站点和站点内比较，以扩展和丰富我们对这些站点的生物多样性及其动态的认识，并为了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，他们将记录地栖蚂蚁的物种和群落如何对中部平原遗址（科罗拉多短草草原）、塞维利亚遗址（草原和奇瓦瓦沙漠之间的过渡）和乔尔纳达遗址（奇瓦瓦沙漠）之间的植被和土地利用的局部和区域梯度做出反应。这项工作的重点是地栖蚂蚁，因为它们很容易取样和观察，数量丰富多样，具有强烈的行为和竞争相互作用，对小尺度和大尺度环境变化都很敏感，并且可能在干旱和半干旱生态系统中的物质运动中发挥重要作用。这些地点代表了温度、降水、植被和生物地理的梯度。在每个站点内，将比较以草为主和灌木为主的植被以及不同放牧强度地点的蚂蚁群落和功能角色。在觅食个体的巢穴以及从食物站移除种子和粉虫的观察将用于记录不同功能群的蚂蚁在一个地点的栖息地中产生的物质流的相对大小如何不同，以及这些差异如何受到区域尺度上运作的因素的影响。

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.