In paleoclimatology of the Holocene, the Boreal was the first of the Blytt-Sernander sequence of north European climatic phases that were originally based on the study of Danish peat bogs, named for Axel Blytt and Rutger Sernander, who first established the sequence. Paleoclimatology (also Palaeoclimatology) is the study of Climate change taken on the scale of the entire History of Earth. The Holocene is a Geological epoch which began approximately 10000 years ago (about 8000 BC The Blytt-Sernander classification or sequence is a series of north European climatic periods or phases based on the study of Danish Peat bogs by Axel Northern Europe is a term for the northern part of Europe. The United Nations defines Northern Europe as (Finland Axel Gudbrand Blytt (1843-1898 was a Norwegian botanist His father was M In peat bog sediments, the Boreal is also recognized by its characteristic pollen zone. Pollen zones are a system of subdividing late Pleistocene and early Holocene paleoclimate using the data from Pollen cores The sequence provides a It was preceded by the Younger Dryas, the last cold snap of the Pleistocene, and followed by the Atlantic, a warmer and moister period than our most recent climate. The Younger Dryas Stadial, named after the alpine / tundra wildflower Dryas octopetala, and also referred to as the Big Freeze, was a brief (approximately The Pleistocene ('plaɪstəsin is the epoch from 18 million to 10000 years BP covering the world's recent period The Atlantic in palaeoclimatology was the warmest and most moist Blytt-Sernander period Pollen zone and chronozone of Holocene north Europe. The Boreal, transitional between the two periods, varied a great deal, at times comprising within it climates like today's.
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Subdividing the Boreal
Subsequent to the original Blytt-Sernander scheme, the first stage of the Boreal was divided off as a Pre-boreal transitional phase, followed by the Boreal proper. Some current schemes based on pollen zones also distinguish a pre-Boreal (pollen zone IV), an early Boreal (pollen zone V) and a late Boreal (pollen zone VIa, b, and c).
Dating
The generally accepted date for the end of the Younger Dryas and the start of the Pre-Boreal is 11,500 Before Present calibrated. The Younger Dryas Stadial, named after the alpine / tundra wildflower Dryas octopetala, and also referred to as the Big Freeze, was a brief (approximately Before Present (BP years are a time scale used in Archaeology, Geology, and other scientific disciplines to specify when events in the past occurred The start of the period is relatively sharply defined by a rise of 7 °C in 50 years. The date is based fairly solidly on Greenland ice cores, which give 11,640 BP for the late Younger Dryas and 11,400 BP for the early Pre-Boreal. Greenland (Kalaallit Nunaat meaning "Land of the Greenlanders" Grønland is a self-governing Danish Province located between the An ice core is a Core sample from the accumulation of snow and ice over many years that have re-crystallized and have trapped air bubbles from previous time periods
But estimates of other dates vary by up to 1000 years, for a number of reasons. First, "Boreal" can identify a paleoclimate, a pollen zone or a temporally-fixed chronozone, and those three bases of definition allow quite different dates. Second, different dating methods obtain different dates. The underlying problem is that climate and pollen vary somewhat from region to region. The scientists of each region use the methods available in their region, whether lake varves, the annual layers of sediment from ancient or modern lake bottoms, ice cores or counts of tree rings (dendrochronology). A varve is an annual layer of Sediment or Sedimentary rock. The word 'varve' is derived from the Swedish word varv whose Dendrochronology (from Greek grc δένδρον dendron, "tree" grc χρόνος khronos, "time" and grc -λογία
Standardization has become of increasing concern to scientists everywhere. Dates from many methods continue to multiply as paleoclimatologists seek higher resolution. But it is unclear whether regional variation will allow high-resolution standardization.
Yet, there are some solid dates of the Pre-Boreal and Boreal. The Saksunarvatn tephra (an ash layer of volcanic fall-out), is dated in Greenland ice to 10,180 plus or minus 60 BP; in lake deposits at Krakenes in Norway, to 10,010-9,980 years BP calibrated; in northwest German lakes, to 10,090 years BP calibrated. In the new science of Tephrochronology, Saksunarvatn tephra are volcanic ejecta that form an ash layer that is useful in dating Northern European sediment layers that were laid The tephra occurs in early Boreal contexts. So, it seems certain that the early Boreal (pollen zone V) includes the year 10,000 BP. Similarly, the late Boreal includes the Kilian/Vasset tephra of Swiss and southwest German lakes at 8200 BP, all calibrated. But the borders are less certain.
Studies of bogs in northwest Russia are the basis for a division of the Preboreal (PB) into PB-1, 10,000-9800, and PB-2, 9800-9300 BP uncal. A bog or mire is a Wetland type that accumulates Acidic Peat, a deposit of dead plant material &ndash usually Mosses but also Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending The scheme goes on to divide the Boreal (BO) into BO-1, 9300-9000, BO-2, 9000-8500, and BO-3, 8500-8000, uncal. CalPal used on these dates suggests overall boundaries of 11,500 and 10,500 BP for the Pre-Boreal, and the end of the Boreal at 8900.
Dates given recently are usually earlier than those given more than 10 years ago. For example, Iverson (1973) and Rud (1979) give dates of 10,000-9000 BP for the Pre-Boreal and 9000-8000 BP for the Boreal, which are uncalibrated C-14 dates based on Scandinavian pollen stratigraphy.
Presumably, more recent dates are more accurate, as technology improves with time, often quite rapidly. Yet, pollen and climate phases also to some degree may depend on latitude, so no date can be regarded as certainly wrong. Scientists look for the overall pattern of the dates, but that technique is not 100% reliable, either.
Description
Before the Pre-Boreal, Eurasia was locked in the chill of the Younger Dryas and was a mostly continuous tundra belt, with regions of taiga, covered with a blanket of grasses, shrubs and other low plants typical of open land. For the superstate in George Orwell 's novel see Nations of Nineteen Eighty-Four. In physical Geography, tundra is an area where the Tree growth is hindered by low temperatures and short growing seasons Taiga (ˈtaɪgə from Turkic or Mongolian) is a Biome characterized by Coniferous forests Large numbers of herbivores wandered in herds over vast distances. Herbivory is a form of Predation in which an Organism, known as a herbivore, consumes principally Autotrophs ref name=Campbell>Campbell The blanket teemed with small, rapidly reproducing species, which supported food chains of larger predators. The largest predators and humans hunted the mammals of the open tundra.
The Pre-Boreal began with a sudden rise in temperature that abruptly changed this ecosystem. Forest replaced the open lands in Europe, and forest-dwelling animals spread from southern refugia and replaced the ice-age tundra mammals; new climax ecosystems developed. In biology a refugium (plural refugia is a location of an isolated or Relict Population of a once widespread animal or plant species The old fauna persisted in Central Asia, but were soon hunted out, as they were not replenished by the larger areas formerly nourishing the ecosystem.
The sea brought additional isolation by rising rapidly and drowning the entire coast. Ireland was cut off early in the Boreal, suffering an impovershment of species. It is home to only two-thirds of the species present in Britain. Britain was cut off by the end of the Boreal. Forest had closed over the former European tundra.
Humans had to adapt to the encroaching forest or move east with the large mammals. Those who stayed became hunter-gatherers of the forests and fishers of the numerous bays, inlets and shallow waters around the thousands of islands that now spangled the seas of Europe. They lived richly and were encouraged to enter the pre-productive phase that we call the Mesolithic. The Mesolithic or Middle Stone Age was a period in the development of human technology in between the Paleolithic or Old Stone Age and the Neolithic or New Stone Age Those who moved east hunted out the last of wild big game and turned their best efforts into learning to herd what was left. In the Americas, humans had left the Paleoindian phase and were now in the Archaic. Paleo-Indians or Paleo-Americans were the ancient peoples of the Americas who were present at the end of the last Ice Age. In the sequence of North American Pre-Columbian cultural stages first proposed by Gordon Willey and Philip Phillips in 1958 the Archaic period
Meanwhile humanity toward the south of the north temperate zone had already turned to food production in a number of widely separated locations and were on the brink of civilization. There is no evidence of any extensive contact with the cultures of the north during the Boreal. The producers tended to live in dense centers without any interest in moving from there except when motivated to find new lands. The gatherers ranged widely over their lands, building only temporary settlements in which to spend the winter.
Flora
During the Pre-Boreal pollen zone IV, large quantities of tree pollen began to replace the pollen of open-land species, as the most mobile and flexible arboreal species colonized their way northward, replacing the ice-age tundra plants. Foremost among them were the birches, Betula pubescens and Betula pendula, accompanied by Sorbus aucuparia and Quaking Aspen, Populus tremula. Birch is the name of any Tree of the genus Betula ( Bé-tu-la) in the family Betulaceae, closely related to the Betula pubescens ( Downy Birch; also known as White Birch, European White Birch or Hairy Birch) is a species of Birch Sorbus aucuparia ( Rowan or European Rowan) is a species of the genus Sorbus (subgenus Sorbus) native to most of Europe Aspens are Trees of the willow family and comprise a section of the Poplar genus Populus sect Especially sensitive to temperature changes and moving northward almost immediately were Juniperus nana and J. communis, the dwarf and shrub Juniper respectively, which reached a maximum density in the Pre-Boreal, before their niches were shaded out. Junipers are Coniferous plants in the genus Juniperus of the cypress family Cupressaceae. Pine soon followed, for which reason the resulting open woodland is often called a birch or a pine-birch forest. This article is about the tree For other uses of the term "pine" see Pine (disambiguation.
In the yet warmer early Boreal pollen zone V, Corylus avellana (hazel) and pine expanded into the birch woodlands to such a degree that palynologists refer to the resulting ecology as the hazel-pine forest. The hazels ( Corylus) are a genus of Deciduous Trees and large Shrubs native to the temperate northern hemisphere Palynology is the science that studies contemporary and fossil Palynomorphs including Pollen, Spores, Dinoflagellate Cysts Acritarchs In the late Boreal it was supplanted by the spread of a deciduous forest called the mixed-oak forest. Pine, birch and hazel were reduced in favor of Quercus, Ulmus, Tilia and Alnus. The term oak can be used as part of the common name of any of about 400 species of Trees and Shrubs in the Genus Quercus (from Latin Elms are Deciduous and Semi-deciduous Trees comprising the genus Ulmus, family Ulmaceae, found Tilia is a Genus of about 30 species of Trees native throughout most of the temperate Northern Hemisphere, in Asia (where the greatest Alder is the common name of a Genus of Flowering plants ( Alnus) belonging to the Birch family (Family Betulaceae) The former tundra was now closed by a canopy of dense forest. In the marshland Typha latifolia prevailed. Typha latifolia ( Bulrush, Common Bulrush, Broadleaf Cattail, Common Cattail, or Cat-o'-nine-tails) is a perennial Less cold-tolerant species such as ivy and mistletoe were to be found in Denmark. Hedera (English name ivy, plural ivies) is a genus of 15 species of climbing or ground-creeping Evergreen woody plants in the family Mistletoe is the common name for a group of hemi-parasitic Plants in the order Santalales that grow attached to and within the The Kingdom of Denmark ( ˈd̥ænmɑɡ̊ (archaic ˈd̥anmɑːɡ̊ commonly known as Denmark, is a country in the Scandinavian region of northern Europe
 Corylus coppice |  Typha latifolia |  Oak forest |  An alder forest at Strömsinlahti, Roihuvuori, Helsinki |
Fauna
The new forest was populated with animals from refugia in Italy, Spain and the Balkans. In biology a refugium (plural refugia is a location of an isolated or Relict Population of a once widespread animal or plant species Animals such as Emys orbicularis (European pond tortoise), which require warmer temperatures, were to be found in Denmark. The European pond terrapin (also European pond turtle or European pond tortoise) Emys orbicularis is a Turtle found in southern and central The Kingdom of Denmark ( ˈd̥ænmɑɡ̊ (archaic ˈd̥anmɑːɡ̊ commonly known as Denmark, is a country in the Scandinavian region of northern Europe The Eurasian golden plover came as far north as Norway. The Eurasian Golden Plover, Pluvialis apricaria, is a largish Plover. Norway ( Norwegian: Norge ( Bokmål) or Noreg ( Nynorsk) officially the Kingdom of Norway, is a Constitutional
The plains Perissodactyla (horses, rhinoceros, etc. The odd-toed ungulates are browsing and Grazing Mammals which compose the order Perissodactyla. ) were replaced by forest Cervidae: Cervus elaphus (red deer), Capreolus capreolus (roe deer) and Alces alces (elk). A deer is a Ruminant Mammal belonging to the family Cervidae. The Red Deer ( Cervus elaphus) is one of the largest Deer species The European Roe Deer ( Capreolus capreolus) is a Deer species of Europe, Asia Minor, and Caspian coastal regions The moose (North America or elk (Europe Alces alces, is the largest extant Species in the Deer family. Sus scrofa (wild pig) rooted around in the oaks, while Bos primigenius (aurochs) haunted the glades and thickets, creating a state of awed unease for human travellers. The boar or wild boar ( Sus scrofa) is an Omnivorous, gregarious Mammal of the biological family Suidae. The aurochs or urus ( Bos taurus primigenius) was a very large type of cattle that was prevalent in Europe until its Extinction in 1627 The forest had its share of predators: Canis lupus (wolf), Ursus arctos (brown bear), Lynx lynx (lynx), Felis sylvestris (wildcat). The grey wolf or gray wolf ( Canis lupus) also known as the timber wolf or simply wolf, is a Mammal of the order Carnivora The Brown Bear ( Ursus arctos) is an Omnivorous Mammal of the family Ursidae, distributed across much of northern Eurasia and A lynx is any of four medium-sized wild cats. All are members of the Genus Lynx, but there is considerable confusion about the best way to classify The Wildcat ( Felis silvestris) sometimes Wild Cat or Wild-cat, is a small felid native to Europe, the western part of Asia Lepus europaeus (hare) provided a tasty meal for any who could catch them. Hares and jackrabbits are Leporids belonging to the Genus Lepus.
The inland waters were as today's European waters would be if they were left alone. Castor fiber (beaver) increased the wetlands by damming the streams and ponds. Beavers are two primarily nocturnal semi-aquatic species of Rodent, one native to North America and one to Europe Lutra lutra (otter) hunted for fish there. Otters are semi- aquatic (or in one case aquatic) fish-eating Mammals The otter subfamily Lutrinae forms part of the family Such fish as Esox lucius (northern pike) and Siluris glanis (catfish) could be found in inexhaustible abundance. The northern pike (known as the pike in Britain Esox lucius, is a Species of carnivorous Fish of the genus Esox (the pikes Catfish ( order Siluriformes) are a very diverse group of bony Fish. The continuous Boreal forests must surely have been the wonderful and frightening wilderness remembered in legend.
Humans
The Preboreal-Boreal in Europe was a time of transition from the Palaeolithic cultures to the Mesolithic. The term Paleolithic (or Palaeolithic) (from Greek παλαιός palaios, " Old " and λίθος Lithos, "stone" The Mesolithic or Middle Stone Age was a period in the development of human technology in between the Paleolithic or Old Stone Age and the Neolithic or New Stone Age Forests and drowned coastlands were places of plenty. Human settlements avoided the deep forest in favor of streams, lakes and especially bays of the ocean. A stream is a body of Water with a current, confined within a bed and stream-banks A lake (from Latin lacus) is a Terrain feature (or Physical feature) a body of Liquid on the surface of a world that is localized to the Headlands and bays are two related features of the coastal environment An ocean (from Greek, ''Okeanos'' (Oceanus) is a major body of saline water, and a principal component of the Hydrosphere.
Pre-Boreal settlements have been found in north-central Europe, such as at Friesack. Friesack is a town in the Havelland district in Brandenburg, Germany. There an unusual find of net fragments made from plant fibers suggested that fishing was an important part of life.
Finds from another settlement at Vis, near the Vychegda river in Russia, offer more details of life in a settlement of the Boreal. Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending Plant fibers were used for baskets and for hafting bone points to shafts. A basket is a container which is traditionally constructed from stiff fibres often made of Willow. Fishermen crossed the waters in bark boats plied by oars, and set nets. An oar is an implement used for water-borne propulsion. Oars have a flat blade at one end They also made hand-held nets from wooden hoops and plant fiber.
Food gathering continued in winter: skis and sledge runners have been found. A ski is a long flat device worn on the feet designed to help the wearer slide smoothly over snow Reindeer continued to be hunted and probably herded. Bows, arrows and spears have been found. Implements were likely to be embellished by sculpting in wood or bone. Only a few motifs were used: the elk's head, the snake, and human.
In Europe, the major culture was the Maglemosian (9000-6400 BC), extending into Denmark and Russia. Maglemosian (ca 7500 BC - ca 6000 BC) is the name given to a culture of the early Epipaleolithic period in Northern Europe. The Kingdom of Denmark ( ˈd̥ænmɑɡ̊ (archaic ˈd̥anmɑːɡ̊ commonly known as Denmark, is a country in the Scandinavian region of northern Europe Localized cultures inclided the Nieman of Lithuania, the Kunda of Latvia and Estonia, the Azilian of France and the Epi-Gravettian of Italy. "Nieman" and "Niemen" redirects here For other uses see Neman and Nieman (disambiguation. Lithuania, officially the Republic of Lithuania (Lietuvos Respublika is a Country in Eastern often referred to as Northern Europe or in the Latvia ( Latvija officially the Republic of Latvia (Latvijas Republika is a Country in Northern Europe in the Baltic region. Estonia, officially the Republic of Estonia ( Eesti or Eesti Vabariik) is a Country in Northern Europe in the Baltic region The Azilian is a name given by Archaeologists to an industry of the Epipaleolithic in northern Spain and southern France. This article is about the country For a topic outline on this subject see List of basic France topics. Italy (Italia officially the Italian Republic, (Repubblica Italiana is located on the Italian Peninsula in Southern Europe, and on the two largest Towards the end of the Mesolithic, local traditions began to multiply, perhaps due to influences from the south, or due to the general advance of culture.
External links
- Late-Glacial/Holocene transition
- Early to mid Holocene calcareous tufa
- Paleoclimate Reconstruction
- The Flandrian
- Central Europe
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