{"title":"牙买加泥灰岩湖中的浮游动物群对水文、湖面和碳循环的反应:一项古生态学调查","authors":"Hannah Greenway, Jonathan Holmes, Michael Burn","doi":"10.5194/jm-43-81-2024","DOIUrl":null,"url":null,"abstract":"Abstract. Ostracod taxa from shallow freshwater lakes are sensitive to a range of limnological factors including temperature, hydrological habitat, lake level, and the distribution of aquatic plants. Ostracod assemblages preserved in Quaternary lake sediments can be used to reconstruct limnological change and are therefore potentially valuable palaeoenvironmental proxies. However, lack of autecological information about some taxa may limit the validity of such reconstructions. We use fossil ostracod assemblages recovered from radiocarbon-dated late Holocene sediments from Wallywash Great Pond, a small, shallow freshwater lake in southwestern Jamaica, to reconstruct limnological change over the past ∼ 1800 years. We circumvent ongoing taxonomic and ecological uncertainties associated with the identification of fossil ostracod taxa by drawing on observations of the ecology of ostracods found living in Jamaican water bodies. By combining this information with limnological data from the extant lake, and with sedimentological and isotopic data from the lake sediments, we show that a published interpretation of ostracod assemblages for the late Quaternary of Wallywash Great Pond is simplistic, at least for the late Holocene section of the sediment record. We conclude that changes in ostracod assemblages are linked to variations in the input of undersaturated groundwater to the northern part of the lake from which the core was recovered. These variations, which were driven by changes in the precipitation / evaporation ratio (effective moisture), also controlled sedimentation, with reduced effective moisture and a decline in undersaturated groundwater input favouring marl precipitation, whereas organic sediments are linked to increased effective moisture and enhanced groundwater input. Our findings suggest that the dramatic shifts in ostracod assemblages at this site are a complex response to changes in hydrology, sedimentology, and carbonate saturation rather than being a simple indicator of lake-level change. Combining ostracod assemblage data with the results of other palaeolimnological analyses also allows more detailed reconstructions to be made for this lake, and such a multiproxy approach is recommended for similar lakes elsewhere.\n","PeriodicalId":54786,"journal":{"name":"Journal of Micropalaeontology","volume":null,"pages":null},"PeriodicalIF":4.1000,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"The response of ostracod faunal assemblages to hydrology, lake level, and carbon cycling in a Jamaican marl lake: a palaeolimnological investigation\",\"authors\":\"Hannah Greenway, Jonathan Holmes, Michael Burn\",\"doi\":\"10.5194/jm-43-81-2024\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract. Ostracod taxa from shallow freshwater lakes are sensitive to a range of limnological factors including temperature, hydrological habitat, lake level, and the distribution of aquatic plants. Ostracod assemblages preserved in Quaternary lake sediments can be used to reconstruct limnological change and are therefore potentially valuable palaeoenvironmental proxies. However, lack of autecological information about some taxa may limit the validity of such reconstructions. We use fossil ostracod assemblages recovered from radiocarbon-dated late Holocene sediments from Wallywash Great Pond, a small, shallow freshwater lake in southwestern Jamaica, to reconstruct limnological change over the past ∼ 1800 years. We circumvent ongoing taxonomic and ecological uncertainties associated with the identification of fossil ostracod taxa by drawing on observations of the ecology of ostracods found living in Jamaican water bodies. By combining this information with limnological data from the extant lake, and with sedimentological and isotopic data from the lake sediments, we show that a published interpretation of ostracod assemblages for the late Quaternary of Wallywash Great Pond is simplistic, at least for the late Holocene section of the sediment record. We conclude that changes in ostracod assemblages are linked to variations in the input of undersaturated groundwater to the northern part of the lake from which the core was recovered. These variations, which were driven by changes in the precipitation / evaporation ratio (effective moisture), also controlled sedimentation, with reduced effective moisture and a decline in undersaturated groundwater input favouring marl precipitation, whereas organic sediments are linked to increased effective moisture and enhanced groundwater input. Our findings suggest that the dramatic shifts in ostracod assemblages at this site are a complex response to changes in hydrology, sedimentology, and carbonate saturation rather than being a simple indicator of lake-level change. Combining ostracod assemblage data with the results of other palaeolimnological analyses also allows more detailed reconstructions to be made for this lake, and such a multiproxy approach is recommended for similar lakes elsewhere.\\n\",\"PeriodicalId\":54786,\"journal\":{\"name\":\"Journal of Micropalaeontology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.1000,\"publicationDate\":\"2024-05-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Micropalaeontology\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.5194/jm-43-81-2024\",\"RegionNum\":3,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"PALEONTOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Micropalaeontology","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.5194/jm-43-81-2024","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"PALEONTOLOGY","Score":null,"Total":0}
引用次数: 0
摘要
摘要浅水淡水湖泊中的梭形纲类群对一系列湖泊学因素(包括温度、水文生境、湖泊水位和水生植物的分布)非常敏感。保存在第四纪湖泊沉积物中的梭形纲类群可用于重建湖泊变化,因此可能是有价值的古环境代用指标。然而,缺乏某些类群的自生态信息可能会限制此类重建的有效性。我们利用从牙买加西南部一个小型浅淡水湖瓦利瓦什大池塘(Wallywash Great Pond)放射性碳年代测定的全新世晚期沉积物中提取的梭形纲动物化石组合来重建过去 1800 年的湖泊变化。我们通过对生活在牙买加水体中的梭形纲动物生态学的观察,规避了与化石梭形纲动物分类鉴定相关的分类学和生态学方面的不确定性。通过将这些信息与现存湖泊的湖泊学数据以及湖泊沉积物的沉积学和同位素数据相结合,我们表明,已发表的对瓦利沃什大池塘第四纪晚期梭形纲动物群落的解释是简单化的,至少对全新世晚期的沉积物记录部分是如此。我们的结论是,浮游生物组合的变化与未饱和地下水输入湖泊北部(岩心取自该处)的变化有关。这些变化由降水/蒸发比(有效湿度)的变化所驱动,同时也控制着沉积作用,有效湿度的降低和未饱和地下水输入的减少有利于泥灰岩的沉积,而有机沉积物则与有效湿度的增加和地下水输入的增强有关。我们的研究结果表明,该地点浮游生物群的巨大变化是对水文、沉积学和碳酸盐饱和度变化的复杂反应,而不是湖面变化的简单指标。将浮游生物组合数据与其他古近代学分析结果相结合,还可以对该湖泊进行更详细的重建,建议其他地方的类似湖泊采用这种多代理方法。
The response of ostracod faunal assemblages to hydrology, lake level, and carbon cycling in a Jamaican marl lake: a palaeolimnological investigation
Abstract. Ostracod taxa from shallow freshwater lakes are sensitive to a range of limnological factors including temperature, hydrological habitat, lake level, and the distribution of aquatic plants. Ostracod assemblages preserved in Quaternary lake sediments can be used to reconstruct limnological change and are therefore potentially valuable palaeoenvironmental proxies. However, lack of autecological information about some taxa may limit the validity of such reconstructions. We use fossil ostracod assemblages recovered from radiocarbon-dated late Holocene sediments from Wallywash Great Pond, a small, shallow freshwater lake in southwestern Jamaica, to reconstruct limnological change over the past ∼ 1800 years. We circumvent ongoing taxonomic and ecological uncertainties associated with the identification of fossil ostracod taxa by drawing on observations of the ecology of ostracods found living in Jamaican water bodies. By combining this information with limnological data from the extant lake, and with sedimentological and isotopic data from the lake sediments, we show that a published interpretation of ostracod assemblages for the late Quaternary of Wallywash Great Pond is simplistic, at least for the late Holocene section of the sediment record. We conclude that changes in ostracod assemblages are linked to variations in the input of undersaturated groundwater to the northern part of the lake from which the core was recovered. These variations, which were driven by changes in the precipitation / evaporation ratio (effective moisture), also controlled sedimentation, with reduced effective moisture and a decline in undersaturated groundwater input favouring marl precipitation, whereas organic sediments are linked to increased effective moisture and enhanced groundwater input. Our findings suggest that the dramatic shifts in ostracod assemblages at this site are a complex response to changes in hydrology, sedimentology, and carbonate saturation rather than being a simple indicator of lake-level change. Combining ostracod assemblage data with the results of other palaeolimnological analyses also allows more detailed reconstructions to be made for this lake, and such a multiproxy approach is recommended for similar lakes elsewhere.
期刊介绍:
The Journal of Micropalaeontology (JM) is an established international journal covering all aspects of microfossils and their application to both applied studies and basic research. In particular we welcome submissions relating to microfossils and their application to palaeoceanography, palaeoclimatology, palaeobiology, evolution, taxonomy, environmental change and molecular phylogeny.