Sedimentary carbon forms in relation to climate and phytoplankton biomass in a large, shallow, hard-water boreal lake

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• 作者：Kristiina Ehapalu ; Ilmar Tõnno ; Triin Reitalu ; Tiiu Alliksaar…
• 关键词：Climate ; NAOw ; Phytoplankton paleobiomass ; Sedimentary carbon ; Path analyses ; Võrtsjärv
• 刊名：Journal of Paleolimnology
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：57
• 期：1
• 页码：81-93
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Paleontology; Sedimentology; Climate Change; Physical Geography; Freshwater & Marine Ecology; Geology;
• 出版者：Springer Netherlands
• ISSN：1573-0417
• 卷排序：57

文摘

Carbon storage in lakes can have huge implications for the global carbon cycle, as lakes annually accumulate up to one half the amount of organic carbon buried in marine sediments. Yet little is known of the effect of recent climate change on carbon storage in lakes. We analyzed century-scale time series of climate variables (precipitation, temperature, NAO winter index) and profiles of sediment characteristics in a dated sediment core from shallow, eutrophic Lake Võrtsjärv, south Estonia. We used path analysis to evaluate the effect of climate conditions on phytoplankton biomass in the lake and accumulation of organic and inorganic carbon in the sediment. Changes in winter and spring climate influenced the lake’s phytoplankton growth significantly. Carbon pathways in hard-water Lake Võrtsjärv were influenced by both hydrological (most significant in colder periods) and biogeochemical processes. Increased nutrient and water input to Lake Võrtsjärv, anticipated with projected climate warming, favours greater in-lake productivity, larger accumulation of inorganic carbon in sediments, and an increase in organic carbon mineralisation, which fuels atmospheric greenhouse gas emissions from the lake.