A Finnish chironomid- and chaoborid-based inference model for reconstructing past lake levels

Luoto, Tomi P.

doi:10.1016/j.quascirev.2009.01.015

Cited by 66 publications

(84 citation statements)

References 44 publications

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“…Indeed, in agreement with the population growth records for Finland (Kuosmanen et al, 2016, and references therein), marked human-induced land-use changes in the catchments of varved lakes in southwestern and south-central Finland became discernible at ∼ 1400 AD (Tiljander et al, 2003;Ojala and Alenius, 2005). This interval coincides with the onset of the LIA, during which both precipitation (Väliranta et al, 2007;Helama et al, 2009;Luoto, 2009;Saarni et al, 2015) and soil erosion rate (Tiljander et al, 2003;Ojala and Alenius, 2005;Saarni et al, 2016) increased in south-central Finland. However, this period is characterized by a shift to suppressed primary productivity at our study site, implying no influence of enhanced external nutrient inputs.…”

Section: Temporal Fluctuations In the Organic Matter Inputsupporting

confidence: 82%

A 1500-year multiproxy record of coastal hypoxia from the northern Baltic Sea indicates unprecedented deoxygenation over the 20th century

et al. 2018

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Abstract. The anthropogenically forced expansion of coastal hypoxia is a major environmental problem affecting coastal ecosystems and biogeochemical cycles throughout the world. The Baltic Sea is a semi-enclosed shelf sea whose central deep basins have been highly prone to deoxygenation during its Holocene history, as shown previously by numerous paleoenvironmental studies. However, long-term data on past fluctuations in the intensity of hypoxia in the coastal zone of the Baltic Sea are largely lacking, despite the significant role of these areas in retaining nutrients derived from the catchment. Here we present a 1500-year multiproxy record of near-bottom water redox changes from the coastal zone of the northern Baltic Sea, encompassing the climatic phases of the Medieval Climate Anomaly (MCA), the Little Ice Age (LIA), and the Modern Warm Period (MoWP). Our reconstruction shows that although multicentennial climate variability has modulated the depositional conditions and delivery of organic matter (OM) to the basin the modern aggravation of coastal hypoxia is unprecedented and, in addition to gradual changes in the basin configuration, it must have been forced by excess human-induced nutrient loading. Alongside the anthropogenic nutrient input, the progressive deoxygenation since the beginning of the 1900s was fueled by the combined effects of gradual shoaling of the basin and warming climate, which amplified sediment focusing and increased the vulnerability to hypoxia. Importantly, the eutrophication of coastal waters in our study area began decades earlier than previously thought, leading to a marked aggravation of hypoxia in the 1950s. We find no evidence of similar anthropogenic forcing during the MCA. These results have implications for the assessment of reference conditions for coastal water quality. Furthermore, this study highlights the need for combined use of sedimentological, ichnological, and geochemical proxies in order to robustly reconstruct subtle redox shifts especially in dynamic, non-euxinic coastal settings with strong seasonal contrasts in the bottom water quality.

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Section: Temporal Fluctuations In the Organic Matter Inputsupporting

confidence: 82%

A 1500-year multiproxy record of coastal hypoxia from the northern Baltic Sea indicates unprecedented deoxygenation over the 20th century

et al. 2018

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“…CC BY 4.0 License. of the LIA, during which both precipitation (Väliranta et al, 2007;Helama et al, 2009;Luoto, 2009;Saarni et al, 2015) and soil erosion rate (Tiljander et al, 2003;Ojala and Alenius, 2005;Saarni et al, 2016) increased in south-central Finland.…”

Section: ) 25mentioning

confidence: 99%

A 1500-year multiproxy record of coastal hypoxia from the northern Baltic Sea indicates unprecedented deoxygenation over the 20<sup>th</sup> century

Jokinen¹,

Virtasalo²,

Jilbert³

et al. 2018

Preprint

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Abstract. The anthropogenically forced expansion of coastal hypoxia is a major environmental problem affecting coastal ecosystems and biogeochemical cycles throughout the world. The Baltic Sea is a semi-enclosed shelf sea whose central deep basins have been highly prone to deoxygenation during its Holocene history, as shown previously by numerous paleoenvironmental studies. However, long-term data on past fluctuations in the intensity of hypoxia in the coastal zone of the Baltic Sea are largely lacking, despite the significant role of these areas in retaining nutrients derived from the catchment.Here 5 we present a 1500-year multiproxy record of near-bottom water redox changes from the coastal zone of the northern Baltic Sea, encompassing the climatic phases of the Medieval Climate Anomaly (MCA), the Little Ice Age (LIA), and the Modern Warm Period (MoWP). Our reconstruction shows that although multicentennial climate variability has modulated depositional conditions and delivery of organic matter (OM) to the basin the modern aggravation of coastal hypoxia is unprecedented, and besides gradual changes in the basin configuration, it must have been forced by excess human-induced nutrient loading. The 10 progressive deoxygenation since the beginning of 1900s was originally triggered by the combined effects of gradual shoaling of the basin and warming climate, which amplified sediment focusing and increased the vulnerability to hypoxia. Importantly, the anthropogenic eutrophication of coastal waters in our study area began decades earlier than previously thought, leading to a marked aggravation of hypoxia in the 1950s through fueling primary productivity, while we find no evidence of anthropogenic forcing during the MCA. These results have implications for the assessment of reference conditions for coastal 15 water quality. Furthermore, this study highlights the need for combined use of sedimentological, ichnological, and geochemical proxies in order to robustly reconstruct subtle redox shifts especially in dynamic, non-euxinic coastal settings with strong seasonal contrasts in the bottom water quality. 25Biogeosciences Discuss., https://doi

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“…Abbreviations: LA, Latitude; LO, longitude; NR, the number of rings, NS, the number of tree-ring series; NT, the number of trees; LS, the mean length of the series in years; FY and LA, the first (FY) and last (LY) calendar year (A.D.) of the site chronology; and LC, the total length of the chronology in years. (Luoto, 2009;Nevalainen et al, 2011;Nevalainen and Luoto, 2012). Lit-1 and Lit-2 are tree-ring sites studied by Pukienė (1997) and Edvardsson et al (2016), respectively.…”

Section: Tree-ring Datamentioning

confidence: 99%

“…Several palaeolimnological studies have recently concentrated on Lake Iso Lehmälampi (Luoto, 2009;Nevalainen et al, 2011;Nevalainen and Luoto, 2012) situated in southern Finland (60.33° N; 24.60° E). This site may represent an ideal comparison with tree-ring chronologies for several reasons.…”

Section: Palaeolimnological Reconstructionsmentioning

confidence: 99%

“…1, the Palmer Drought Severity Index (PDSI) reflecting spring-summer soil moisture conditions ; 2, the water level reconstruction based on subfossil chironomid midge (dashed line) and cladoceran water flea (solid lines; calibrations from intra-site by thick line and multi-site training sets by thin line) communities in Lake Iso Lehmälampi (Luoto, 2009;Nevalainen et al, 2011;Nevalainen and Luoto, 2012); and 3, the replication curves of the subfossil tree-ring chronologies constituting a peatland and eight lake sites (this study).…”

Section: Figurementioning

confidence: 99%

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Rereading a tree-ring database to illustrate depositional histories of subfossil trees

Helama

Luoto

Nevalainen

et al. 2017

Palaeontologia Electronica

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A Finnish chironomid- and chaoborid-based inference model for reconstructing past lake levels

Cited by 66 publications

References 44 publications

A 1500-year multiproxy record of coastal hypoxia from the northern Baltic Sea indicates unprecedented deoxygenation over the 20th century

A 1500-year multiproxy record of coastal hypoxia from the northern Baltic Sea indicates unprecedented deoxygenation over the 20th century

A 1500-year multiproxy record of coastal hypoxia from the northern Baltic Sea indicates unprecedented deoxygenation over the 20<sup>th</sup> century

Rereading a tree-ring database to illustrate depositional histories of subfossil trees

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A Finnish chironomid- and chaoborid-based inference model for reconstructing past lake levels

Cited by 66 publications

References 44 publications

A 1500-year multiproxy record of coastal hypoxia from the northern Baltic Sea indicates unprecedented deoxygenation over the 20th century

A 1500-year multiproxy record of coastal hypoxia from the northern Baltic Sea indicates unprecedented deoxygenation over the 20th century

A 1500-year multiproxy record of coastal hypoxia from the northern Baltic Sea indicates unprecedented deoxygenation over the 20&lt;sup&gt;th&lt;/sup&gt; century

Rereading a tree-ring database to illustrate depositional histories of subfossil trees

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A 1500-year multiproxy record of coastal hypoxia from the northern Baltic Sea indicates unprecedented deoxygenation over the 20<sup>th</sup> century