Trends in development of diatom flora from sub-recent lake sediments of the Lake Bolshoy Kharbey (Bolshezemelskaya tundra, Russia)

We studied diatom assemblages of the proglacial arctic lake Bolshoy Kharbey (Bolshezemelskaya tundra, Russian Arctic) from a short sediments core covering the last ca. 200 years. In total, 121 taxa from 2 classes, 5 orders, 18 families, and 50 genera were identified. The diatom flora included species with mainly cosmopolitan distribution. The assemblages were dominated by alkaliphilic benthic diatoms preferring standing — flowing waters, indifferent to salinity and moderate temperature conditions. The main changes in diatom assemblages took place in ca. 1870 and 1980. After 1870, which can be attributed to the end of the Little Ice Age, the species richness rose, especially of planktonic centric and small penate diatoms. This rise of diatom diversity took place most probably in response to climate warming, related to it prolongation of the growing season and period of open water. A negative trend in the evenness of the diatom assemblages during the last decades can be seen as an early-warning signal indicating a decrease of stability of the lake ecosystem.

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A High-Resolution 11,400-Yr Diatom Record from Lake Victoria, East Africa

Quaternary Research ◽

10.1006/qres.1996.1863 ◽

1997 ◽

Vol 47 (1) ◽

pp. 81-89 ◽

Cited By ~ 102

Author(s):

J.Curt Stager ◽

Brian Cumming ◽

Loren Meeker

Keyword(s):

Little Ice Age ◽

Lake Victoria ◽

Ice Age ◽

Pollen Record ◽

Diatom Assemblages ◽

Climatic Fluctuations ◽

The Past ◽

Phytoplankton Communities ◽

Abrupt Changes ◽

Globally Distributed

AbstractFine-interval (∼30–45 yr) sampling of a core from Lake Victoria's Damba Channel shows that numerous abrupt changes in the lake's diatom assemblages have occurred in response to climatic fluctuations over the past 11,40014C yr. Four distinct climatic phases bounded by sudden transitions are inferred: (1) variably dry ∼11,400–10,000 yr B.P., (2) humid ∼10,000–7200 yr B.P., (3) more seasonal ∼7200–2200 yr B.P., and (4) more arid ∼2200–0 yr B.P., with a dry “Little Ice Age” event ∼600–200 yr B.P. The diatom-inferred paleoclimatic history for northern Lake Victoria closely resembles that inferred from a well-dated pollen record from Pilkington Bay. Spectral analysis of the diatom record reveals strong periodicities including globally distributed ∼2360–2550, ∼1400, ∼1030–1130, and ∼500 cal-yr cycles. Repeated, rapid shifts betweenAulacoseira- andNitzschia-dominated diatom assemblages suggest that post-1960 changes in the lake's phytoplankton communities have had earlier, climate-driven analogs.

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Diatoms and other siliceous indicators track the ontogeny of a bofedal (wetland) ecosystem in the Peruvian Andes

Botany ◽

10.1139/cjb-2020-0196 ◽

2021 ◽

Author(s):

Connor King ◽

Neal Michelutti ◽

Carsten Meyer-Jacob ◽

Richard Bindler ◽

Pedro Tapia ◽

...

Keyword(s):

Little Ice Age ◽

Ice Core ◽

Water System ◽

Open Water ◽

Ice Age ◽

Peruvian Andes ◽

Peat Core ◽

The Andes ◽

Recent Warming ◽

The Many

Recent warming in the Andes is affecting the region’s water resources including glaciers and lakes, which supply water to tens of millions of people downstream. High altitude wetlands, known locally as bofedales, are an understudied Andean ecosystem despite their key role in carbon sequestration, maintaining biodiversity, and regulating water flow. Here, we analyze subfossil diatom assemblages and other siliceous bioindicators preserved in a peat core collected from a bofedal in Peru’s Cordillera Vilcanota. Basal radiocarbon ages show the bofedal likely formed during a wet period of the Little Ice Age (1520-1680 CE), as inferred from nearby ice core data. The subfossil diatom record is marked by several dynamic assemblage shifts documenting a hydrosere succession from an open-water system to mature peatland. The diatoms appear to be responding largely to changes in hydrology that occur within the natural development of the bofedal, but also to pH and possibly nutrient enrichment from grazing animals. The rapid peat accretion recorded post-1950 at this site is consistent with recent peat growth rates elsewhere in the Andes. Given the many threats to Peruvian bofedales including climate change, overgrazing, peat extraction, and mining, these baseline data will be critical to assessing future change in these important ecosystems.

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Impact of the ‘Little Ice Age’ climate cooling on the maar lake ecosystem affected by penguins: A lacustrine sediment record, Penguin Island, West Antarctica

The Holocene ◽

10.1177/0959683616683254 ◽

2017 ◽

Vol 27 (8) ◽

pp. 1115-1131 ◽

Cited By ~ 2

Author(s):

Agnieszka Wasiłowska ◽

Andrzej Tatur ◽

Zinajda Pushina ◽

Andrzej Barczuk ◽

Sergey Verkulich

Keyword(s):

Sediment Core ◽

Little Ice Age ◽

Photosynthetic Pigment ◽

Sudden Change ◽

Ice Age ◽

Lake Ecosystem ◽

Flat Bottom ◽

Phytoplankton Assemblages ◽

Maar Lake ◽

Climate Cooling

A Pliocene-age volcano on Penguin Island became active again in the Pleistocene/Holocene, forming the main cone of the island – Deacon Peak, and leaving late-Holocene phreatomagmatic craters, including ‘Petrel Crater’, about 200 m in diameter and filled currently by a maar lake with a flat bottom at 18 m water depth. Petrographic, geochemical, photosynthetic pigment, and diatom data from the 72-cm-long sediment core reveal that the crater was initially a marine lagoon with typical phytoplankton assemblages. Most probably, tectonic–volcanic activity about 1250 years ago, documented in tephra fallout, triggered an abrupt glacio-isostatic uplift that separated the lake from the sea. The horizon of tephra, probably from the Deception Island volcano, marks a sudden change in environment from brackish to lacustrine. The ecological evolution of the lake was initially constrained by an uplift, whereas the influence of marine water vanished with time, the lake became meromictic, and the freshwater mixolimnion layer expanded, while the monimolimnion became anoxic due to the influence of a penguin rookery situated on the shore. During the ‘Little Ice Age’ (LIA), the maar may have been covered by permanent ice. A discharge of mineralized guano from the possibly enlarged penguin rookery on the lake shore caused an expansion of the anoxic monimolimnion to the ice surface and an important reduction of autochthonous lacustrine biota of the maar, whereas a substantially increased participation of allochthonous biota passively supplied with guano. That record in the lake sediment core reaffirms the occurrence of a regional LIA event in the maritime Antarctic.

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Preliminary Report on the Late Pleistocene and Holocene Diatoms of Swamp Lake, Yosemite National Park, California, USA

Phytotaxa ◽

10.11646/phytotaxa.127.1.14 ◽

2013 ◽

Vol 127 (1) ◽

pp. 128 ◽

Cited By ~ 2

Author(s):

SCOTT W. STARRATT ◽

R. SCOTT ANDERSON

Keyword(s):

Little Ice Age ◽

National Park ◽

Ice Age ◽

Yosemite National Park ◽

Medieval Climate Anomaly ◽

Diatom Assemblages ◽

Climate Anomaly ◽

Varved Sediments ◽

Freeze Core ◽

Large Fluctuations

Swamp Lake, Yosemite National Park, is the only known lake in California containing long sequences of varved sediments and thus has the potential to provide a high-resolution record of climate variability. This preliminary analysis of the diatom assemblages from a 947-cm-long composite sediment core (freeze core FZ02–05; 0–67 cm, Livingstone core 02–05; 53–947 cm) shows that the lake has been freshwater, oligotrophic, and circumneutral to alkaline throughout its ~16,000-year-long history. The first sediments deposited in the lake show that the vegetation in the watershed was sparse, allowing organic matter-poor silt and clay to be deposited in the basin. The basin filled quickly to a depth of at least 5 m and remained at least that deep for most of the sediment record. Several short intervals provided evidence of large fluctuations in lake level during the Holocene. The upper 50 cm of the core contains evidence of the Medieval Climate Anomaly and Little Ice Age.

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Absence of a Medieval Climate Anomaly, Little Ice Age and twentieth century warming in Skarvsnes, Lützow Holm Bay, East Antarctica

Antarctic Science ◽

10.1017/s0954102014000029 ◽

2014 ◽

Vol 26 (5) ◽

pp. 585-598 ◽

Cited By ~ 11

Author(s):

Ines Tavernier ◽

Elie Verleyen ◽

Dominic A. Hodgson ◽

Katrien Heirman ◽

Stephen J. Roberts ◽

...

Keyword(s):

Twentieth Century ◽

Southern Hemisphere ◽

Northern Hemisphere ◽

Little Ice Age ◽

Environmental Changes ◽

Open Water ◽

Ice Age ◽

Medieval Climate Anomaly ◽

Climate Anomaly ◽

The Past

AbstractPalaeoclimate changes, such as the Medieval Climate Anomaly and the Little Ice Age, are well-defined in the Northern Hemisphere during the past 2000 years. In contrast, these anomalies appear to be either absent, or less well-defined, in high-latitude regions of the Southern Hemisphere. Here, we inferred environmental changes during the past two millennia from proxies in a sediment core from Mago Ike, an East Antarctic lake in Skarvsnes (Lützow Holm Bay). Variations in lake primary production were inferred from fossil pigments, sedimentological and geochemical proxies and combined with absolute diatom counts to infer past diatom productivity and community changes. Three distinct stratigraphic zones were recognized, resulting from a shift from marine to lacustrine conditions with a clear transition zone in between. The presence of open-water marine diatoms indicates a coastal zone seasonally free of sea ice between c. 2120–1500 cal yr bp. Subsequently, the lake became isolated from the ocean due to isostatic uplift. Freshwater conditions were established from c. 1120 cal yr bp onwards after which the proxies are considered highly sensitive to temperature changes. There is no evidence for a Medieval Climate Anomaly, Little Ice Age or twentieth century warming in our lake sediment record suggesting that studies that have imposed Northern Hemisphere climate anomalies onto Southern Hemisphere palaeoclimate records should be treated with caution.

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Greenhouses, hot water bottles, cycles and the future of New Zealand climate

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.2009.71.2772 ◽

2009 ◽

pp. 61-67

Author(s):

W.P. De Lange

Keyword(s):

New Zealand ◽

Thermal Energy ◽

Infrared Radiation ◽

Little Ice Age ◽

Hot Water ◽

Ice Age ◽

The Sun ◽

Weather Patterns ◽

Time Periods ◽

Almost All

The Greenhouse Effect acts to slow the escape of infrared radiation to space, and hence warms the atmosphere. The oceans derive almost all of their thermal energy from the sun, and none from infrared radiation in the atmosphere. The thermal energy stored by the oceans is transported globally and released after a range of different time periods. The release of thermal energy from the oceans modifies the behaviour of atmospheric circulation, and hence varies climate. Based on ocean behaviour, New Zealand can expect weather patterns similar to those from 1890-1922 and another Little Ice Age may develop this century.

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Holocene diatom assemblages from Dunderbukhta sediments, West Svalbard

Issues of modern algology (Вопросы современной альгологии) ◽

10.33624/2311-0147-2019-2(20)-242-245 ◽

2019 ◽

pp. 242-245

Author(s):

Ksenya V. Poleshchuk ◽

Zinaida V. Pushina ◽

Sergey R. Verkulich

Keyword(s):

Environmental Changes ◽

Ecological Groups ◽

Diatom Assemblages ◽

Diatom Analysis ◽

Diatom Flora ◽

Sediment Samples ◽

Ecological Zones ◽

Middle Holocene ◽

Temperature Trends

The diatom analysis results of sediment samples from Dunderbukta area (Wedel Jarlsberg Land, West Svalbard) are presented in this paper. The diatom flora consists of four ecological groups, which ratio indicates three ecological zones. These zones show environmental changes of the area in early–middle Holocene that is demonstrating periods of regression and temperature trends.

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