气候变化领域集成服务门户(CCPortal): Ecohydrological evolution of Lake Naivasha (central Rift Valley; Kenya) during the past 1650 years; as recorded by ostracod assemblages and stable-isotope geochemistry

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DOI	10.1016/j.quascirev.2019.105906
	Ecohydrological evolution of Lake Naivasha (central Rift Valley; Kenya) during the past 1650 years; as recorded by ostracod assemblages and stable-isotope geochemistry
	Van der Meeren T.; Ito E.; Laird K.R.; Cumming B.F.; Verschuren D.
发表日期	2019
ISSN	0277-3791
卷号	223
英文摘要	Lake Naivasha (central Rift Valley, Kenya) is regionally unique in having accumulated a continuous sediment record of climate-driven palaeohydrological change over the past 1650 years, attesting to dramatic shifts between freshwater high-stands and either fresh or saline low-stands. This study employs fossil ostracod assemblages and stable-isotope (δ18O and δ13C) signatures to disclose the lake's ecohydrological history and explain the evolving non-linearity between lake level and salinity. The original age model and lithology-based lake-level reconstruction are revised, and the diatom-inferred salinity reconstruction is expanded to the lower (pre-770 CE) part of the record. The stable-isotope time series showed limited coherence with the other proxies, probably due to complexities related to hydrological connections between different surface- and groundwater components shifting through time. Ostracod palaeoecological data indicate that between ca 350 and 1200 CE the system often veered towards hydrological closure, with frequent and high-amplitude shifts in lake level and salinity preventing long-term establishment of wetland vegetation. Low lake-level and saline conditions dominated between ca 900 and 1200 CE. After that time and particularly since the onset of more permanent Malewa River inflow ca 1430 CE, hydrologically open conditions prevailed. Salinity shifts exhibited lower amplitude and frequency, promoting the expansion of wetland vegetation and associated biota including benthivorous fish. With lake water balance strongly influenced by variation in river inflow, high-amplitude lake-level fluctuations continued throughout the freshwater phase of the past 600 years, notably creating a pronounced high-stand dated to ca 1600–1780 CE and the well-documented extreme low-stand of the early 1800s. © 2019 Elsevier Ltd
英文关键词	East Africa; Holocene; Lake level; Lake Naivasha; Palaeolimnology; Salinity fluctuations
语种	英语
scopus关键词	Animals; Climate change; Exploratory geochemistry; Groundwater; Groundwater geochemistry; Isotopes; Lithology; Vegetation; Wetlands; East Africa; Holocenes; Lake levels; Lake Naivasha; Palaeolimnology; Salinity fluctuation; Lakes; ecohydrology; fossil assemblage; fossil record; geochemistry; Holocene; lake level; lake water; new record; ostracod; paleoecology; paleoenvironment; paleolimnology; reconstruction; rift zone; salinity; stable isotope; Kenya; Kenya; Lake Naivasha; Nakuru; Bacillariophyta; Ostracoda
来源期刊	Quaternary Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/151736
作者单位	Department of Biology, Ghent University, K. L. Ledeganckstraat 35, Gent, 9000, Belgium; Department of Earth Sciences and Limnological Research Center, University of Minnesota, 310 Pillsbury Drive SE, Minneapolis, MN 55455, United States; Department of Biology, Queen's University, 116 Barrie St., Kingston, ON K7L 3N6, Canada
推荐引用方式 GB/T 7714	Van der Meeren T.,Ito E.,Laird K.R.,et al. Ecohydrological evolution of Lake Naivasha (central Rift Valley; Kenya) during the past 1650 years; as recorded by ostracod assemblages and stable-isotope geochemistry[J],2019,223.
APA	Van der Meeren T.,Ito E.,Laird K.R.,Cumming B.F.,&Verschuren D..(2019).Ecohydrological evolution of Lake Naivasha (central Rift Valley; Kenya) during the past 1650 years; as recorded by ostracod assemblages and stable-isotope geochemistry.Quaternary Science Reviews,223.
MLA	Van der Meeren T.,et al."Ecohydrological evolution of Lake Naivasha (central Rift Valley; Kenya) during the past 1650 years; as recorded by ostracod assemblages and stable-isotope geochemistry".Quaternary Science Reviews 223(2019).