ESH - Late Quaternary Climate Change and Biotic Responses inthe Bonneville Basin and Vicinity, Northeastern Great Basin

ESH - 东北大盆地邦纳维尔盆地及周边地区晚第四纪气候变化和生物反应

• 批准号: 9709502
• 负责人: David Rhode
• 金额: $ 10.41万
• 依托单位: Nevada System of Higher Education, Desert Research Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 2000-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9709502&HistoricalAwards=false
• 关键词: ESH; Late; Quaternary; Climate; Change

9709502 Rhode The Bonneville Basin of western Utah and eastern Nevada has one of the best known late Pleistocene paleoenvironmental records in the world, but our understanding of the history of terrestrial biota in the region lags behind our understanding of lake levels or regional paleoclimates. Recently a large number of ancient packrat middens have been collected from the mountains surrounding the Great Salt Lake Desert, providing a rich source of fossil plant and animal remains dating through the last 50,000 years. Under this proposal, a series of analyses of these midden samples will be undertaken. Samples from these middens will be radiocarbon dated to derive a long term chronology of midden strata. Plant macrofossils, pollen, insect remains, and vertebrate faunal elements will be identified, to reconstruct biotic distributions through time. Stomatal density and concentrations of stable isotopes of hydrogen and carbon will be examined to determine changes in water use efficiency of certain plant taxa (limber pine) in response to changes in climate and atmospheric chemistry during the glacial-interglacial cycle. Postulated changes in body size of the bushy-tailed woodrat in response to climate change during this same time period will be evaluated using fecal pellets as a proxy measure. When these data sets are integrated together, this midden record will be used to identify and date major shifts in vegetation associations, the distribution of insect and vertebrate taxa, and changes in physiology and morphology of plant and animal taxa in response to dramatic changes in climate and atmospheric CO2 concentration, within a single regional ecosystem during the last 50,000 years. These data will provide the basis for paleoclimatic estimates in the region to complement and cross-check other paleoclimatic proxy data and climate model results from the Bonneville Basin, contributing to one of the most detailed and well dated long-term terrestrial records of climate change and responses b y geological and biological systems available.

小行星9709502 位于犹他州西部和内华达州东部的邦纳维尔盆地拥有世界上最著名的晚更新世古环境记录之一，但我们对该地区陆地生物群历史的理解落后于我们对湖泊水位或区域古气候的理解。 最近，人们从大盐湖沙漠周围的山脉中采集到了大量的古代食鼠贝，为过去5万年的植物和动物化石提供了丰富的来源。 根据这项建议，将对这些垃圾箱样本进行一系列分析。 从这些贝冢中提取的样本将进行放射性碳年代测定，以得出贝冢地层的长期年代学。 将鉴定植物宏化石、花粉、昆虫遗骸和脊椎动物区系成分，以重建生物在时间上的分布。 将对气孔密度以及氢和碳的稳定同位素浓度进行检查，以确定某些植物分类群（软松）在冰川-间冰期循环期间因气候和大气化学变化而产生的水利用效率的变化。 在同一时期，将使用粪便颗粒作为替代措施来评估灌木尾林鼠对气候变化的反应，以估计其体型的变化。 当这些数据集被整合在一起，这midden记录将被用来确定和日期的重大变化，植被协会，昆虫和脊椎动物类群的分布，以及在生理和形态的变化的植物和动物类群，以应对气候和大气CO2浓度的急剧变化，在一个单一的区域生态系统在过去的50,000年。 这些数据将为该地区的古气候估计提供基础，以补充和交叉检查来自Bonneville盆地的其他古气候代用数据和气候模型结果，从而为气候变化和B y地质和生物系统反应的最详细和最早的长期陆地记录之一做出贡献。