The Holocene paleoenvironmental history of central European Russia reconstructed from pollen, plant macrofossil, and testate amoeba analyses of the Klukva Peatland, Tula Region

2015 ◽  
Vol 83 (3) ◽  
pp. 459-468 ◽  
Author(s):  
Elena Yu. Novenko ◽  
Andrey N. Tsyganov ◽  
Elena M. Volkova ◽  
Kirill V. Babeshko ◽  
Nikita V. Lavrentiev ◽  
...  
Keyword(s):  
Climatic Variability ◽  
Warming Trend ◽  
European Russia ◽  
Historical Period ◽  
Testate Amoeba ◽  
Central European ◽  
The Holocene ◽  
Plant Macrofossil ◽  
Holocene Thermal Maximum ◽  
History Of

Holocene climatic variability and human impact on vegetation are reconstructed from a region in central European Russia, which lies at an important ecotone between broadleaf forest and steppe. For the first time in this region we adopt a multi-proxy approach that combines analysis of local mire conditions from plant macrofossil and testate amoeba analyses with pollen-based quantitative climate reconstruction. The proxies indicate a long-term warming trend from 9700 to 7500 cal yr BP, interrupted by a series of short-term cold events. From 7500 to 5000 cal yr BP the results imply a relatively stable climate, warmer and drier than present, spanning the Holocene Thermal Maximum. Since 5000 cal yr BP the data suggest a change to cooler climate, but with centennial-scale variability. This shift at around 5000 cal yr BP is supported by extensive evidence from other sites. In the early Holocene, the region was occupied mainly by pine and birch forests. Broad-leafed forests of oak, lime and elm expanded after 7800 cal yr BP and remained dominant until the last few centuries. During the historical period, vegetation changes have been driven mainly by human activities.

Holocene history of boreal forest landscapes of the Central European Russia

2021 ◽  
Author(s):  
Vladimir Belyaev ◽  
Ilya Shorkunov ◽  
Katerina Garankina ◽  
Nikita Mergelov ◽  
Yulia Shishkina ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Late Pleistocene ◽  
Gully Erosion ◽  
European Russia ◽  
Empirical Modeling ◽  
Snowmelt Runoff ◽  
Central European ◽  
The Holocene ◽  
High Magnitude ◽  
Late Pleistocene To Holocene

<p>Recent detailed investigations of landforms, soils and surface deposits of the Borisoglebsk Upland northeastern slope within the Nero Lake basin (Central European Russia, Yaroslavl Region) allowed deciphering co-evolution of the major landscape components of the case study area since the Late Pleistocene. The Late Pleistocene to Holocene transition in the gully network was represented by relatively short but high-magnitude (up to 12 m) incision phase followed by significant infill till 6.5 ka. Absence of the well-developed early Holocene paleosols in the studied sections and cores suggests dominantly negative sediment budget. There is so far limited evidence of sedimentation over the first half of the Holocene. Discontinuous deposition with certain interruptions (but without distinct buried soil formation) occurred only within closed depressions and on gully fans. The second part of the Holocene prior to the widespread human settlement left more substantial traces in soil and sediment record. Despite the common perception of the pristine boreal forest landscapes to be geomorphologically stable due to erosion-protective role of woodland vegetation, several phases of dramatically increased soil and gully erosion rates have been identified. It is identified in soil bodies and sediments, both at locations dominated by denudation (evidences of multiple topsoil truncation in Atlantic and Subatlantic) and at zones of alternating incision and infill of small linear erosion features. Such extremes were most likely associated with combination of several triggers including natural forest fires and high-magnitude rainfall or snowmelt runoff events. There are several <sup>14</sup>C dated layers of pyrogenic charcoal indicating pre-anthropogenic wildfire-induced incision and infill cycles during the middle and late Holocene.</p><p>The last phases of increased hillslope and fluvial activity within the study area can be related to increased human interference, starting from about 1600-900 years ago. The onset of cut-and-burn cultivation is independently established from available archeological evidences, dating of cut and burnt tree logs remnants, organic material buried by agrogenic colluvium and gully fans. Latest period of intensive gully growth can most likely be attributed to the XIX<sup>th</sup> Century land tenure reform, when most of the study area gullies experienced significant linear growth, bottom incisions and appearance of several new gully branches. The most recent trend of soil and gully erosion has been evaluated by <sup>137</sup>Cs sediment tracing, soil empirical modeling and comparison of historical and modern maps, airborne photos and satellite images. Rates of soil redistribution on slopes decreased significantly over the last several decades due to combination of natural and anthropogenic impacts: 1) decreased spring snowmelt runoff caused mainly by generally lowered thickness of seasonally frozen topsoil layer; 2) arable land abandonment or shift from row crops and cereals to perennial grass-dominated crop rotations in the post-Soviet period. In addition, local short-term (from several years to within-year) cycles of relatively low-magnitude (not exceeding ±1 m range) incision and infill in gullies are often triggered by biogenic activities, namely beaver dam constructions and breaches and local log jams.</p><p>The study is supported by the Russian Science Foundation (Project No. 19-77-10061) and Russian Foundation for Basic Research (Project No. 19-29-05238).</p>

scholarly journals Climate and the latitudinal limits of subtropical reef development

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lauren T. Toth ◽  
William F. Precht ◽  
Alexander B. Modys ◽  
Anastasios Stathakopoulos ◽  
Martha L. Robbart ◽  
...  
Keyword(s):  
Sea Level ◽  
Coral Cover ◽  
Climatic Variability ◽  
Extreme Weather Events ◽  
Sea Level Changes ◽  
Reef Development ◽  
The Holocene ◽  
Holocene Thermal Maximum ◽  
Primary Driver ◽  
Southern Florida

AbstractClimate plays a central role in coral-reef development, especially in marginal environments. The high-latitude reefs of southeast Florida are currently non-accreting, relict systems with low coral cover. This region also did not support the extensive Late Pleistocene reef development observed in many other locations around the world; however, there is evidence of significant reef building in southeast Florida during the Holocene. Using 146 radiometric ages from reefs extending ~ 120 km along Florida’s southeast coast, we test the hypothesis that the latitudinal extent of Holocene reef development in this region was modulated by climatic variability. We demonstrate that although sea-level changes impacted rates of reef accretion and allowed reefs to backstep inshore as new habitats were flooded, sea level was not the ultimate cause of reef demise. Instead, we conclude that climate was the primary driver of the expansion and contraction of Florida’s reefs during the Holocene. Reefs grew to 26.7° N in southeast Florida during the relatively warm, stable climate at the beginning of the Holocene Thermal Maximum (HTM) ~ 10,000 years ago, but subsequent cooling and increased frequency of winter cold fronts were associated with the equatorward contraction of reef building. By ~ 7800 years ago, actively accreting reefs only extended to 26.1° N. Reefs further contracted to 25.8° N after 5800 years ago, and by 3000 years ago reef development had terminated throughout southern Florida (24.5–26.7° N). Modern warming is unlikely to simply reverse this trend, however, because the climate of the Anthropocene will be fundamentally different from the HTM. By increasing the frequency and intensity of both warm and cold extreme-weather events, contemporary climate change will instead amplify conditions inimical to reef development in marginal reef environments such as southern Florida, making them more likely to continue to deteriorate than to resume accretion in the future.

scholarly journals Holocene hydrography evolution in the Alboran Sea: a multi-record and multi-proxy comparison

2019 ◽  
Vol 15 (3) ◽  
pp. 927-942 ◽  
Author(s):  
Albert Català ◽  
Isabel Cacho ◽  
Jaime Frigola ◽  
Leopoldo D. Pena ◽  
Fabrizio Lirer
Keyword(s):  
North Atlantic ◽  
Climatic Variability ◽  
Planktonic Foraminifera ◽  
Warming Trend ◽  
Western Mediterranean ◽  
Alboran Sea ◽  
The Holocene ◽  
Sst Variability ◽  
Peak Structure ◽  
Alborán Sea

Abstract. A new high-resolution deglacial and Holocene sea surface temperature (SST) reconstruction is presented for the Alboran Sea (western Mediterranean), based on Mg∕Ca ratios measured in the planktonic foraminifera Globigerina bulloides. This new record is evaluated by comparison with other Mg∕Ca SST records and previously published alkenone SST reconstructions from the same region for both the Holocene and glacial periods. In all cases there is a high degree of coherence between the different Mg∕Ca SST records but strong discrepancies when compared to the alkenone SST records. We argue that these discrepancies are due to differences in the proxy response during deglaciation which we hypothesize to reflect a resilience strategy of G. bulloides, changing its main growth season, and consequently Mg∕Ca records a shorter deglacial warming than alkenones. In contrast, short-term Holocene SST variability is larger in the Mg∕Ca SST than in the alkenone SST records. We propose that the larger Mg∕Ca SST variability is a result of spring temperatures variability, while the smoothed alkenone SST variability represents averaged annual temperatures. The Mg∕Ca SST record differentiates the Holocene into three periods: (1) the warmest SST values occurred during the Early Holocene (11.7–9 cal. kyr BP), (2) a continuous cooling trend occurred during the Middle Holocene that culminated in the coldest Holocene SST having a double cold peak structure centred at around 4.2 cal. kyr BP, and (3) the Late Holocene (4.2 cal. kyr BP to present) did not follow any clear cooling/warming trend although millennial-scale oscillations were enhanced. This SST evolution is discussed in the context of the changing properties in the Atlantic inflow water associated with North Atlantic circulation conditions and also with local hydrographical and atmospheric changes. We propose that a tight link between North Atlantic circulation patterns and the inflow of surface waters into the Mediterranean played a major role in controlling Holocene climatic variability of this region.

Formation, succession and landscape history of Central-European summit raised bogs: A multiproxy study from the Hrubý Jeseník Mountains

The Holocene ◽  
2012 ◽  
Vol 23 (2) ◽  
pp. 230-242 ◽  
Author(s):  
Lydie Dudová ◽  
Petra Hájková ◽  
Hana Buchtová ◽  
Vĕra Opravilová
Keyword(s):  
Transfer Functions ◽  
Testate Amoebae ◽  
Gradual Transition ◽  
Testate Amoeba ◽  
Central European ◽  
Raised Bogs ◽  
Middle Holocene ◽  
Poor Fen ◽  
History Of ◽  
High Conservation

Central-European raised bogs, developed on mountain summits, are specific ecosystems of high conservation importance, but their history remains largely unknown. Pollen, macrofossils, testate amoebae and peat characteristics were analysed in a peat sequence of the Vozka bog (Hrubý Jeseník Mountains, Eastern Sudetes, Czech Republic). Past water chemistry and water-table depths were reconstructed by transfer functions calibrated from recent testate amoeba data and long-term environmental averages. Peat initiation started in the middle Holocene (approximately 4200 bc) by the process of paludification, resembling the development of Atlantic blanket bogs. Around 100 bc the vegetation changed from Eriophorum vaginatum-poor fen to the ombrotrophic-bog vegetation similar to the recent situation. A hiatus in peat sequence was revealed between ad 1320 and 1954. It can be explained either by human activities, or by an extreme drought causing decomposition of previously accumulated peat. Local bog development was largely independent of landscape development inferred from pollen records. In the middle Holocene, mixed spruce-elm-hazel woodland was recorded close to the treeline. During 2400–800 bc a gradual transition to mixed spruce-fir woodlands with admixture of beech took place, and from approximately 800 bc spruce and fir became dominant. The major human impact started approximately ad 1230 and was connected with settlement and mining in the foothills.

The Holocene thermal maximum and late-Holocene cooling in the tundra of NE European Russia

2011 ◽  
Vol 75 (3) ◽  
pp. 501-511 ◽  
Author(s):  
J. Sakari Salonen ◽  
Heikki Seppä ◽  
Minna Väliranta ◽  
Vivienne J. Jones ◽  
Angela Self ◽  
...  
Keyword(s):  
Late Holocene ◽  
Temperature Drop ◽  
Plant Macrofossils ◽  
European Russia ◽  
The Holocene ◽  
Holocene Thermal Maximum ◽  
Northern European ◽  
Thermal Maximum ◽  
Summer Temperatures ◽  
Northern European Russia

AbstractTo investigate the Holocene climate and treeline dynamics in the European Russian Arctic, we analysed sediment pollen, conifer stomata, and plant macrofossils from Lake Kharinei, a tundra lake near the treeline in the Pechora area. We present quantitative summer temperature reconstructions from Lake Kharinei and Lake Tumbulovaty, a previously studied lake in the same region, using a pollen–climate transfer function based on a new calibration set from northern European Russia. Our records suggest that the early-Holocene summer temperatures from 11,500 cal yr BP onwards were already slightly higher than at present, followed by a stable Holocene Thermal Maximum (HTM) at 8000–3500 cal yr BP when summer temperatures in the tundra were ca. 3°C above present-day values. A Picea forest surrounded Lake Kharinei during the HTM, reaching 150 km north of the present taiga limit. The HTM ended with a temperature drop at 3500–2500 cal yr BP associated with permafrost initiation in the region. Mixed spruce forest began to disappear around Lake Kharinei at ca. 3500 cal yr BP, with the last tree macrofossils recorded at ca. 2500 cal yr BP, suggesting that the present wide tundra zone in the Pechora region formed during the last ca. 3500 yr.

Ecological, coenotic and floristic analysis of groups of associations of broadleaved-coniferous forests from central European Russia

2001 ◽  
pp. 38-48 ◽  
Author(s):  
L. B. Zaugolnova ◽  
I. I. Istomina ◽  
E. V. Tikhonova
Keyword(s):  
Wide Distribution ◽  
European Russia ◽  
Coniferous Forests ◽  
Computer Data ◽  
East Europe ◽  
Central European ◽  
Reference Base ◽  
Floristic Analysis ◽  
Regional Factors

Two computer data bases were formed: reference base «Prodromus» including the nomenclature forest syntaxa and experienced geobotanic releves «Forests of European Russia». Ecological, coenotic and floristic analysis of broadleaved-coniferous forests mostly corresponding to association Rhodobryo rosei – Piceetum abietis Korotkov 1986 was conducted with these bases. Releves (305) from South taiga and broadleaved-coniferous subzone were used. The analysis revealed complex syntaxonomy, bo­real-nemoral character and wide distribution ass. Rhodobryo-Piceetum from central European Russia. Ecolo­gical comparison of this association with some no­men­clature types of broadleaved-coniferous communities in East Europe was carried out. Preliminary prodromus for Euro­pean Russian mixed forests is suggested. Role of ecologi­cal, succession and regional factors was shown for dif­ferentiation of syntaxa.

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