GRGC: Holocene Paleoenvironments in the Central Midwest: Vegetation, Climate, and Landscape Evolution

小行星9316391 对北方诸州全新世古环境的研究在很大程度上依赖于孢粉学，它提供了植被和气候变化的相对连续和详细的记录。 然而，在中西部的中部和南部，遗址相对较少，对古环境知之甚少。 本研究的目的是：1）在沿着南北向和东西向的断面上采集一系列的河流切岸样本，以寻找植物遗骸。 这些存款构成了一个相对未被触及的和未知的极好的古环境信息来源; 2）分析这些样品的花粉，特别是植物宏体化石，以提供有关过去植被的信息; 3）重建每个地点、沿着样带以及整个中部中西部的全新世植被和气候;（4）将这些数据加入到北美花粉数据库和即将建立的北美植物宏化石数据库中，以扩充全新世植被和气候变化的模型; 5）继续研究这些沉积的冲积历史和土壤学发展，以便我们可以评估岩石地层学、土壤地层学和景观发展的模式（由E. A.贝蒂斯）从爱荷华州延伸到邻近的州。 该项目将在多个领域发挥重要作用。1)生态/古生态信息将提供包括大草原半岛在内的中西部中部植被发展的第一幅全面图片。 2)这些古气候数据将大大扩展美国中部全新世气候的覆盖范围。 3)气候和植被变化的时间和程度将与一个完全独立的证据来源进行交叉检查;同一地区洞穴石笋的碳和氧同位素，如Gonzalez等人的提案的随附项目摘要中所述。4）植被和气候都将与土壤形成和全新世河流行为变化相关。 5)河流行为和景观发展的变化对于考古学家定位遗址以及了解如何以及在哪里寻找特定年龄的遗址至关重要。

9316391 Baker Studies of Holocene paleoenvironments in the northern tier of states have relied heavily on palynology, which supplies relatively continuous and detailed records of vegetational and climatic change. In the central and southern Midwest, however, sites are relatively rare, and paleoenvironments are poorly known. The objectives of this study are 1) to sample a series of stream cutbanks along north-south and east-west transects for plant remains. These deposit constitute a relatively untouched and unknown source of excellent paleoenvironmental information; 2) to analyze these samples for pollen and especially for plant macrofossils, to provide information on past vegetation; 3) to reconstruct Holocene vegetation and climate for each site, along the transects, and for the entire central Midwest; 4) to add these data to the North American Pollen Database and the soon-to-be- formed North American Plant Macrofossil Database, so that models of Holocene vegetational and climatic change can be extended; 5) to continue to study the alluvial history and pedological development of these deposits, so that we can evaluate how the pattern of lithostratigraphy, soils stratigraphy, and landscape development (produced by E.A. Bettis) extends from Iowa to adjacent states. The project will be significant in several fields. 1) The ecological/paleoecological information will provide the first comprehensive picture of the development of vegetation across the central Midwest, including the Prairie Peninsula. 2) The paleoclimatic data will extend greatly the coverage of Holocene climates in the central United States. 3) The timing and extent of climatic and vegetational changes will be cross-checked with a completely independent source of evidence; carbon and oxygen isotopes from cave stalagmites across the same area, as outline in the accompanying Project Summary of the proposal by Gonzalez et al. 4) Both vegetation and climate will be correlated with soil formatio n and with Holocene changes in stream behavior over a broad area. 5) Changes in stream behavior and landscape development are critically important to archaeologists in locating sites and in understanding how and where to look for sites of specific ages.