Dinoflagellate cysts and other NPP as paleolimnological proxies

许多微观化石在溶解矿物沉积物的苛刻酸处理中幸存下来；这些耐酸微化石(孢粉型)包括众所周知的沉积物花粉记录，反映了周围地区的植被，以及各种各样的非花粉孢粉型(NPP)，包括藻类、真菌、动物、植物，甚至细菌遗骸。由于这些生物有不同的栖息地和生活方式(陆生/水生；光合作用生物/消费者/分解者、海底生物/游泳者和漂浮者)，单一样本中的核动力源提供了关于整个湖泊生态系统及其周围流域的丰富信息。不幸的是，人们对这些微化石以及它们的组合与产生它们的生物群落之间的关系知之甚少。甲藻的包囊将受到特别关注，因为我们(在布罗克)在这一领域拥有非凡的专业知识。湖泊浮游生物和耐受化石的恐囊记录之间的关系特别复杂；它们通常与纤维质动囊膜几乎没有相似之处。结合萌发研究和DNA分析的生物学方法和微古生物(孢粉学)方法，这项研究将有助于我们理解甲藻的生活史和孢囊-囊膜关系。北美东部中纬度地区数十个湖泊的NPP记录将与a)每个湖泊及其分水岭中的动植物种群进行比较；b)水柱和湖床中的物理化学条件(例如温度、pH值、溶解氧、营养水平、重金属浓度)；以及c)湖床沉积物中的其他(非耐酸)微体化石。其目的是阐明这一在分类和生态上不同的群体在水质研究中的潜力，特别是在评估人类对湖泊生态系统的影响方面，并最终建立方程来定量重建影响孢粉形态分布的各种环境参数。统计分析将确定每个物种的偏好和耐受性，然后可用于重建与自然因素(如干旱)和人类活动(如农业)有关的长期变化。沉积物岩心还将从具有相对众所周知的历史(根据历史记录和其他古湖相指标)的各种湖泊(大/小、城市/偏远、混合良好/分层、缓冲良好/对酸化敏感)进行采集，来自地表样本的现代校准数据集将能够重建长期的环境变化。豚草和其他杂草丰度的增加使人们能够确定人类的影响，提供了额外的时间控制，以确定人类引起的水质变化，增加了辐射年龄。

Many microscopic fossils survive harsh acid treatments that dissolve mineral sediments; these acid-resistant microfossils (palynomorphs) include the well-known pollen record of sediments that reflects the vegetation in the surrounding region as well as a wide variety of non-pollen palynomorphs (NPP) that include algae, fungi, animal, plant, and even bacterial remains. Because these have a variety of habitats and lifestyles (terrestrial/ aquatic; photosynthesizers/consumers/decomposers, bottom-dwellers/ swimmers and floaters), NPPs in a single sample provide a wealth of information about the entire lake ecosystem and its surrounding watershed. Unfortunately, relatively little is known about these microfossils and how their assemblages relate to the biological communities that produce them. The cysts of dinoflagellates will receive particular attention because we (at Brock) have exceptional expertise in this field. The relationship between the lake plankton and the resistant fossil dinocyst record is especially complicated; they often bear little resemblance to the cellulosic motile thecae. Combining a biological approach involving germination studies and DNA analysis with a micropaleontological (palynological) approach, this study will aid our understanding of the dinoflagellate life cycle and cyst-theca relationships. The NPP record of several dozen lakes from mid-latitudes in eastern North America will be compared with a) the flora and fauna in each lake and its watershed; b) physico-chemical conditions (e.g., temperature, pH, dissolved oxygen, nutrient levels, heavy metal concentrations) in the water column and on the lakebed, and c) other (non-acid-resistant) microfossils in the lakebed sediments. The aim is to illustrate the potential of this taxonomically and ecologically varied group in studies of water quality, particularly in assessing human impact on lake ecosystems, and ultimately to generate equations to quantitatively reconstruct the various environmental parameters that influence palynomorph distribution. Statistical analysis will determine the preferences and tolerances of each species that can then be used to reconstruct long-term changes related to natural factors (e.g., drought) and human activity (e.g., agriculture). Sediment cores also will be collected from a variety of lakes (large/small, urban/ remote, well-mixed/ stratified, well-buffered/ sensitive to acidification) with relatively well-known histories (based on historic records and other paleolimnological indicators), and the modern calibration dataset from surface samples will allow long-term environmental change to be reconstructed. The increase in abundance of ragweed and other weeds allows the identification of human impact, providing added chronological control to identify human-induced changes in water quality, augmenting radiometric ages.