Collaborative Research: Antarctic Dry Valley Nematode Communities: Establishment, Function, and Response to Disturbance

合作研究：南极干谷线虫群落：建立、功能和对干扰的响应

• 批准号: 9522665
• 负责人: Ross Virginia
• 金额: $ 8.37万
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-01-01 至 1998-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9522665&HistoricalAwards=false
• 关键词: Collaborative; Research; Antarctic; Dry; Valley

9522665 Virginia Nematodes, microscopic roundworms, are among the most complex animals capable of survival in the soils of the Antarctic Dry Valleys. If dispersal of nematodes to habitats is uniform and unlimited by geographical constraints, communities of nematodes could potentially establish in all soils of the Dry Valleys of Antarctica, as they do in other ecosystems studied. Nematode distribution in the Dry Valleys is patchy. It follows that dispersal rates are low, or the establishment of nematode communities is governed by the suitability of potential habitats and the ability of nematodes to survive harsh environmental conditions. Habitat suitability may be defined by such factors as carbon availability or salinity. This research project is organized around central hypotheses that move from individual to ecosystem scales in order to understand how nematodes disperse, survive, and develop functional communities in Antarctic Dry Valley soils. The hypotheses are: (1) nematode community function is more influenced by desiccation than temperature, and (2) habitat suitability, not dispersal, is the major factor determining establishment and maintenance of nematode communities in the Dry Valleys. To test these hypotheses, field work will be conducted to examine the characteristics of habitats that appear suitable for nematode community growth and establishment by sampling from a variety of sites, encompassing a wide range of salinities, moistures, and carbon contents. Stable isotope studies (C and N) will provide information on sources of C entering soil ecosystems and supporting nematodes. Dispersal will be examined with traps in the field, and molecular techniques in the laboratory to investigate the genetic variability that exists between widely distributed nematodes with similar morphological characteristics. The survival strategies of nematodes will be examined under field and laboratory conditions to better understand how these animals are able to persist under harsh climatic conditions. In addition, the soil food web serves as a sensitive indicator of environmental change, particularly in this ecosystem, where biodiversity is low and resource allocation is primarily invested in survival. Any knowledge about the degree of influence of such change, as well as the influence of various physical and chemical soil characteristics, can ultimately extrapolated to other environments.

9522665弗吉尼亚线虫，微观round虫，是在南极干山谷土壤中生存的最复杂的动物之一。 如果将线虫散布到栖息地是统一的，并且受地理约束的无限，那么线虫的群落可能会像在研究的其他生态系统中一样，在南极干燥的所有土壤中建立。 干谷中的线虫分布是斑点的。 因此，分散率很低，或者建立线虫群落受潜在栖息地的适合性以及线虫在恶劣的环境条件下生存的能力。 栖息地适合性可以由诸如碳供应或盐度之类的因素定义。 该研究项目围绕着中心假设进行组织，这些假设从单个生态系统量表转变为生态系统量表，以了解线虫如何在南极干谷土壤中分散，生存和发展功能群落。 假设是：（1）线虫群落功能比温度更受干燥的影响，（2）栖息地的适用性而非分散，是确定干山谷中线虫群落建立和维护的主要因素。为了检验这些假设，将进行现场工作，以检查看起来适合线虫社区增长和建立的栖息地的特征，并通过各种地点进行采样，包括各种盐分，水分和碳含量。 稳定的同位素研究（C和N）将提供有关进入土壤生态系统和支持线虫的C来源的信息。将通过田间的陷阱来检查扩散，并在实验室中的分子技术研究，以研究具有相似形态特征的广泛分布的线虫之间存在的遗传变异性。线虫的生存策略将在现场和实验室条件下进行检查，以更好地了解这些动物如何在恶劣的气候条件下持续存在。 此外，土壤食品网是环境变化的敏感指标，尤其是在这个生物系统中，生物多样性低，资源分配主要投资于生存。 关于这种变化影响程度的任何知识以及各种物理和化学土壤特征的影响，最终都可以推断到其他环境中。