Subatlantic
   HOME

TheInfoList



OR:

The Subatlantic is the current climatic age of the
Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togethe ...
epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided by ...
. It started about 2,500 years BP and is still ongoing. Its average temperatures are slightly lower than during the preceding Subboreal and
Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...
. During its course, the
temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied o ...
underwent several oscillations, which had a strong influence on fauna and flora and thus indirectly on the evolution of human civilizations. With intensifying
industrialisation Industrialisation ( alternatively spelled industrialization) is the period of social and economic change that transforms a human group from an agrarian society into an industrial society. This involves an extensive re-organisation of an econo ...
, human society started to stress the natural climatic cycles with increased
greenhouse gas emissions Greenhouse gas emissions from human activities strengthen the greenhouse effect, contributing to climate change. Most is carbon dioxide from burning fossil fuels: coal, oil, and natural gas. The largest emitters include coal in China and lar ...
.


History and stratigraphy

The term ''subatlantic'' was first introduced in 1889 by
Rutger Sernander Johan ''Rutger'' Sernander (2November 186627October 1944) was a Swedish botanist, geologist and archaeologist. He was one of the founders of the study of palynology which would later be developed by Lennart von Post, as well as a pioneer in the ...
to differentiate it from
Axel Blytt Axel Gudbrand Blytt (19 May 1843 – 18 July 1898) was a Norwegian professor, botanist and geologist. He was the author of a number of books regarding the flora of Norway. Today he is most associated with his role in developing the Blytt-Sernan ...
's ''atlantic''. It follows upon the previous ''subboreal''. According to
Franz Firbas Franz Firbas (born 4 June 1902 in Prague; died 19 February 1964 in Göttingen) was a German botanist who taught at the University of Göttingen. From 1952 to 1964, he was director of their Systematisch-Geobotanisches Institut. Former students inclu ...
(1949) and Litt ''et al.'' (2001) the subatlantic consists of the pollen zones IX and X. This corresponds in the scheme of Fritz Theodor Overbeck to the pollen zones XI and XII. In climate stratigraphy the subatlantic is usually subdivided into an older subatlantic and a younger subatlantic. The older subatlantic corresponds to pollen zone IX (or XI in an alternate nomenclature made of more zones) characterized in central and northern Europe by
beech Beech (''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to temperate Europe, Asia, and North America. Recent classifications recognize 10 to 13 species in two distinct subgenera, ''Engleriana'' and ''Fagus''. The ''Engle ...
or
oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...
-beech forests, the younger subatlantic to pollen zone X (or XII in the alternate nomenclature made of more zones). In eastern
Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
Dietrich Franke subdivides the subatlantic into four stages (from young to old): * youngest subatlantic: 1800 until present:
modern history The term modern period or modern era (sometimes also called modern history or modern times) is the period of history that succeeds the Middle Ages (which ended approximately 1500 AD). This terminology is a historical periodization that is applie ...
* younger subatlantic: 1250 until 1800:
High Middle Ages The High Middle Ages, or High Medieval Period, was the periodization, period of European history that lasted from AD 1000 to 1300. The High Middle Ages were preceded by the Early Middle Ages and were followed by the Late Middle Ages, which ended ...
,
Late Middle Ages The Late Middle Ages or Late Medieval Period was the Periodization, period of European history lasting from AD 1300 to 1500. The Late Middle Ages followed the High Middle Ages and preceded the onset of the early modern period (and in much of Eur ...
, Early Modern Period * middle subatlantic: 500 until 1250:
migration period The Migration Period was a period in European history marked by large-scale migrations that saw the fall of the Western Roman Empire and subsequent settlement of its former territories by various tribes, and the establishment of the post-Roman ...
and
Slavic migrations Slavs are the largest European ethnolinguistic group. They speak the various Slavic languages, belonging to the larger Balto-Slavic branch of the Indo-European languages. Slavs are geographically distributed throughout northern Eurasia, main ...
* older subatlantic: 500 BC until 500 AD: pre-Roman
Iron Age The Iron Age is the final epoch of the three-age division of the prehistory and protohistory of humanity. It was preceded by the Stone Age (Paleolithic, Mesolithic, Neolithic) and the Bronze Age (Chalcolithic). The concept has been mostly appl ...
,
ancient Rome In modern historiography, ancient Rome refers to Roman civilisation from the founding of the city of Rome in the 8th century BC to the collapse of the Western Roman Empire in the 5th century AD. It encompasses the Roman Kingdom (753–509 B ...
and start of migration period.


Ages

The beginning of the subatlantic is usually defined as 2,400 calendar years BP or 450 BC. Yet this lower limit is by no means rigid. Some authors prefer to define the start of the subatlantic as 2,500
radiocarbon Carbon-14, C-14, or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and coll ...
years which represents roughly 625 BC. Occasionally the onset of the subatlantic has been pushed back to 1200 BC. According to Franz Firbas the changeover from the subboreal (pollen zone VIII) to the older subatlantic (pollen zone IX) is characterized by the recession of
hazel The hazel (''Corylus'') is a genus of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family Betulaceae,Germplasmgobills Information Network''Corylus''Rushforth, K. (1999). ...
and
lime Lime commonly refers to: * Lime (fruit), a green citrus fruit * Lime (material), inorganic materials containing calcium, usually calcium oxide or calcium hydroxide * Lime (color), a color between yellow and green Lime may also refer to: Botany ...
and the simultaneous spreading of
hornbeam Hornbeams are hardwood trees in the flowering plant genus ''Carpinus'' in the birch family Betulaceae. The 30–40 species occur across much of the temperate regions of the Northern Hemisphere. Origin of names The common English name ''hornbeam' ...
due to anthropogenic influences. This recession was not synchronous. It occurred in the western reaches of the Lower
Oder The Oder ( , ; Czech, Lower Sorbian and ; ) is a river in Central Europe. It is Poland's second-longest river in total length and third-longest within its borders after the Vistula and Warta. The Oder rises in the Czech Republic and flows thr ...
valley between 930 and 830 BC, whereas in southwestern
Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populous ...
this event had taken place already between 1170 and 1160 BC. The beginning of the younger subatlantic at 1250 AD coincides with the medieval population increase and distinguishes itself by an increase in
pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accep ...
and in indicator plants for human settlements. In
Silesia Silesia (, also , ) is a historical region of Central Europe that lies mostly within Poland, with small parts in the Czech Republic and Germany. Its area is approximately , and the population is estimated at around 8,000,000. Silesia is split ...
this event can be dated between 1050 and 1270 AD. If one equates the onset of the younger subatlantic with the first maximum of beech occurrence it shifts back to
Carolingian The Carolingian dynasty (; known variously as the Carlovingians, Carolingus, Carolings, Karolinger or Karlings) was a Frankish noble family named after Charlemagne, grandson of mayor Charles Martel and a descendant of the Arnulfing and Pippin ...
times around 700 AD.


Climatic evolution

The summer temperatures of the subatlantic are generally somewhat cooler (by up to 1.0 °C) than during the preceding subboreal, the yearly average temperatures reduced by 0.7 °C. At the same time the winter
precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...
s augmented by up to 50%. Overall the climate during the subatlantic therefore tends to cooler and wetter conditions. The lower limit of the
glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...
s in
Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion#Europe, subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, ...
descended during the subatlantic by 100 to 200 meters. The beginning of the subatlantic opened at the middle of the first millennium BC with the so-called
Roman Warm Period The Roman Warm Period, or Roman Climatic Optimum, was a period of unusually-warm weather in Europe and the North Atlantic that ran from approximately 250 BC to AD 400. Theophrastus (371 – c. 287 BC) wrote that date trees could grow in Greece ...
which lasted to the beginning of the 4th century. This corresponds broadly to
classical antiquity Classical antiquity (also the classical era, classical period or classical age) is the period of cultural history between the 8th century BC and the 5th century AD centred on the Mediterranean Sea, comprising the interlocking civilizations of ...
. The optimum is marked by a temperature spike centered around 2,500 BP. As a consequence in Europe the winter temperatures were raised by 0.6 °C during this period, yet on average were still by 0.3 °C lower than during the subboreal.
Ice core An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper ones, and an ice core contains ic ...
s from
Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...
also demonstrate a distinct temperature rise after the younger subboreal. The cooling that followed coincides with the
Migration Period The Migration Period was a period in European history marked by large-scale migrations that saw the fall of the Western Roman Empire and subsequent settlement of its former territories by various tribes, and the establishment of the post-Roman ...
. It was not very pronounced and of short duration – an average temperature drop of 0.2 °C and a winter temperature drop of 0.4 °C center around 350 AD (or 1,600 years BP). This climatic deterioration with the establishment of drier and cooler conditions might have forced the
Huns The Huns were a nomadic people who lived in Central Asia, the Caucasus, and Eastern Europe between the 4th and 6th century AD. According to European tradition, they were first reported living east of the Volga River, in an area that was part ...
to move west thus in turn triggering the migrations of the
Germanic tribes The Germanic peoples were historical groups of people that once occupied Central Europe and Scandinavia during antiquity and into the early Middle Ages. Since the 19th century, they have traditionally been defined by the use of ancient and ear ...
. At about the same time the
Byzantine Empire The Byzantine Empire, also referred to as the Eastern Roman Empire or Byzantium, was the continuation of the Roman Empire primarily in its eastern provinces during Late Antiquity and the Middle Ages, when its capital city was Constantinopl ...
reached its first acme and
Christianity Christianity is an Abrahamic monotheistic religion based on the life and teachings of Jesus of Nazareth. It is the world's largest and most widespread religion with roughly 2.38 billion followers representing one-third of the global pop ...
established itself in Europe as the leading monotheistic religion. After this relatively short cool interlude the climate ameliorated again and reached between 800 and 1200 almost the values of the Roman Warm Period (used temperature proxies are sediments in the North Atlantic). This warming happened during the
High Middle Ages The High Middle Ages, or High Medieval Period, was the periodization, period of European history that lasted from AD 1000 to 1300. The High Middle Ages were preceded by the Early Middle Ages and were followed by the Late Middle Ages, which ended ...
wherefore this event is known as ''Medieval Global Warming'' or the
Medieval Warm Period The Medieval Warm Period (MWP), also known as the Medieval Climate Optimum or the Medieval Climatic Anomaly, was a time of warm climate in the North Atlantic region that lasted from to . Proxy (climate), Climate proxy records show peak warmth oc ...
. This warmer climate peaked around 850 AD and 1050 AD, and raised the
tree line The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures, extreme snowp ...
in
Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion#Europe, subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, ...
and in
Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...
by 100 to 140 meters; it enabled the
Vikings Vikings ; non, víkingr is the modern name given to seafaring people originally from Scandinavia (present-day Denmark, Norway and Sweden), who from the late 8th to the late 11th centuries raided, pirated, traded and se ...
to settle in
Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its s ...
and
Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...
. During this period the
Crusades The Crusades were a series of religious wars initiated, supported, and sometimes directed by the Latin Church in the medieval period. The best known of these Crusades are those to the Holy Land in the period between 1095 and 1291 that were in ...
took place and the Byzantine Empire was eventually pushed back by the rise of the
Ottoman Empire The Ottoman Empire, * ; is an archaic version. The definite article forms and were synonymous * and el, Оθωμανική Αυτοκρατορία, Othōmanikē Avtokratoria, label=none * info page on book at Martin Luther University) ...
. The end of the Medieval Warm Period coincides with the early 14th century reaching a temperature minimum around 1350, and by the
Crisis of the Late Middle Ages The Crisis of the Late Middle Ages was a series of events in the fourteenth and fifteenth centuries that ended centuries of European stability during the Late Middle Ages. Three major crises led to radical changes in all areas of society: demog ...
. Many settlements were abandoned and left deserted. As a consequence, the population in
Central Europe Central Europe is an area of Europe between Western Europe and Eastern Europe, based on a common historical, social and cultural identity. The Thirty Years' War (1618–1648) between Catholicism and Protestantism significantly shaped the area' ...
drastically receded by as much as 50 percent. After a short warming pulse around 1500, the
Little Ice Age The Little Ice Age (LIA) was a period of regional cooling, particularly pronounced in the North Atlantic region. It was not a true ice age of global extent. The term was introduced into scientific literature by François E. Matthes in 1939. Ma ...
followed, lasting from c. 1550 until 1860. The
Northern Hemisphere The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...
snow line The climatic snow line is the boundary between a snow-covered and snow-free surface. The actual snow line may adjust seasonally, and be either significantly higher in elevation, or lower. The permanent snow line is the level above which snow wil ...
descended by 100 to 200 meters. Human history during this time includes
the Renaissance The Renaissance ( , ) , from , with the same meanings. is a period in European history marking the transition from the Middle Ages to modernity and covering the 15th and 16th centuries, characterized by an effort to revive and surpass ideas ...
and the
Age of Enlightenment The Age of Enlightenment or the Enlightenment; german: Aufklärung, "Enlightenment"; it, L'Illuminismo, "Enlightenment"; pl, Oświecenie, "Enlightenment"; pt, Iluminismo, "Enlightenment"; es, La Ilustración, "Enlightenment" was an intel ...
, and also major rebellious events like the
Thirty Years War The Thirty Years' War was one of the longest and List of wars and anthropogenic disasters by death toll, most destructive conflicts in History of Europe, European history, lasting from 1618 to 1648. Fought primarily in Central Europe, an es ...
and the
French Revolution The French Revolution ( ) was a period of radical political and societal change in France that began with the Estates General of 1789 and ended with the formation of the French Consulate in November 1799. Many of its ideas are considere ...
. The beginning of the
Industrial Revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
also dates back to this period, while
Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...
experienced the
Post-Angkor Period The post-Angkor period of Cambodia ( km, ប្រទេសកម្ពុជាក្រោយសម័យអង្គរ), also called the Middle Period and Dark Age ( km, យុគ្គអន្ធកាល, lit=Isolationism, link=yes; ( km ...
. From 1860 onwards, the temperatures started to rise again and initiated the modern climatic optimum. This warming was severely amplified by anthropogenic influences (i.e. increasing industrialisation,
greenhouse gas emissions Greenhouse gas emissions from human activities strengthen the greenhouse effect, contributing to climate change. Most is carbon dioxide from burning fossil fuels: coal, oil, and natural gas. The largest emitters include coal in China and lar ...
and
global warming In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
). The modern warming shows a distinct temperature rise from the 1970s onwards. According to NASA, this is not expected to change within the 21st century.


Atmosphere

Ice core An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper ones, and an ice core contains ic ...
analyses from
Greenland Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is t ...
and
Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...
show a very similar evolution in
greenhouse gases A greenhouse gas (GHG or GhG) is a gas that absorbs and emits radiant energy within the thermal infrared range, causing the greenhouse effect. The primary greenhouse gases in Earth's atmosphere are water vapor (), carbon dioxide (), methane ...
. After a temporary minimum during the preceding subboreal and atlantic the concentrations of
carbon monoxide Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...
,
nitrous oxide Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or nos, is a chemical compound, an oxide of nitrogen with the formula . At room temperature, it is a colourless non-flammable gas, and has a ...
and
methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Eart ...
slowly started to rise during the Subatlantic. Since 1800 onwards this rise has dramatically accelerated paralleling roughly the concomitant temperature rise. For example, the CO2-concentration increased from 280 ppm to a recent value of nearly 400 ppm, methane from 700 to 1800 ppb and N2O from 265 to 320 ppb. A comparable rise had already taken place at the changeover to the Holocene, but this process then took nearly 5,000 years. This sudden release of greenhouse gases into the atmosphere by human society represents an unprecedented experiment with unpredictable consequences for Earth's climate. Within the same context the release of juvenile
water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...
tied up in fossil fuels like
coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dea ...
,
lignite Lignite, often referred to as brown coal, is a soft, brown, combustible, sedimentary rock formed from naturally compressed peat. It has a carbon content around 25–35%, and is considered the lowest rank of coal due to its relatively low heat ...
,
gas Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or ...
and
petrol Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organic co ...
is generally overlooked.


Sea level

During the 2,500 year duration of the subatlantic global
sea level Mean sea level (MSL, often shortened to sea level) is an average surface level of one or more among Earth's coastal bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical datuma standardised g ...
kept on rising by about 1 meter. This corresponds to a rather low rate of 0.4 millimeters per year. Yet at the end of the 19th century a drastic change can be witnessed with a rate increase to 1.8 mm per year in the period 1880 to 2000. In the last twenty years alone
satellite A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope ...
measurements document a rise of 50 millimeters which corresponds to a sixfold increase on the pre-industrial rate and a new rise of 2.5 millimeters per year.


Evolution in the Baltic

Today's sea level was already reached during the oldest subatlantic by the third Litorina transgression. The sea level rise had amounted to 1 meter, since then it oscillated around the zero mark. The transgression established during the ''postlitorine phase'' the Limnea Sea, which is characterized by lower
salinity Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...
compared with the preceding
Littorina Sea Littorina Sea (also Litorina Sea) is a geological brackish water stage of the Baltic Sea, which existed around 7500–4000 BP and followed the Mastogloia Sea, a transitional stage of the Ancylus Lake. This stage and form of the body of wat ...
due to an isostatic shallowing of the
Danish Danish may refer to: * Something of, from, or related to the country of Denmark People * A national or citizen of Denmark, also called a "Dane," see Demographics of Denmark * Culture of Denmark * Danish people or Danes, people with a Danish a ...
sea straits (
Great Belt The Great Belt ( da, Storebælt, ) is a strait between the major islands of Zealand (''Sjælland'') and Funen (''Fyn'') in Denmark. It is one of the three Danish Straits. Effectively dividing Denmark in two, the Belt was served by the Great Be ...
,
Little Belt The Little Belt (, ) is a strait between the island of Funen and the Jutland Peninsula in Denmark. It is one of the three Danish Straits that drain and connect the Baltic Sea to the Kattegat strait, which drains west to the North Sea and Atlant ...
and Öresund). As a consequence the
sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...
''
Littorina littorea The common periwinkle or winkle (''Littorina littorea'') is a species of small edible whelk or sea snail, a marine gastropod mollusc that has gills and an operculum, and is classified within the family Littorinidae, the periwinkles.Reid, David ...
'' was gradually replaced by the freshwater snail '' Limnaea ovata''. During the middle subatlantic about 1,300 years ago another rather weak sea level rise took place. Yet the salinity kept falling and therefore new freshwater species were able to immigrate. During the younger and youngest subatlantic about 400 years ago the Limnea Sea was replaced by the Mya Sea as distinguished by the immigration of the
clam Clam is a common name for several kinds of bivalve molluscs. The word is often applied only to those that are edible and live as infauna, spending most of their lives halfway buried in the sand of the seafloor or riverbeds. Clams have two she ...
''
Mya arenaria Soft-shell clams (American English) or sand gaper (British English/Europe), scientific name ''Mya arenaria'', popularly called "steamers", "softshells", "piss clams", "Ipswich clams", or "Essex clams" are a species of edible saltwater clam, a ...
'' which eventually gave way to the recent
Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...
.


Evolution of the North Sea area

In the
North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...
area, which had experienced a slight sea level fall and sea level stagnation during the subboreal, the renewed transgressive pulses of the Dunkerque transgression during the older subatlantic achieved the recent level.


Vegetation history

The wet and cool older subatlantic (pollen zone IX a) is characterized in central Europe by an
oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...
forest intruded more and more by
beech Beech (''Fagus'') is a genus of deciduous trees in the family Fagaceae, native to temperate Europe, Asia, and North America. Recent classifications recognize 10 to 13 species in two distinct subgenera, ''Engleriana'' and ''Fagus''. The ''Engle ...
(mixed oak forests with
lime Lime commonly refers to: * Lime (fruit), a green citrus fruit * Lime (material), inorganic materials containing calcium, usually calcium oxide or calcium hydroxide * Lime (color), a color between yellow and green Lime may also refer to: Botany ...
and
elm Elms are deciduous and semi-deciduous trees comprising the flowering plant genus ''Ulmus'' in the plant family Ulmaceae. They are distributed over most of the Northern Hemisphere, inhabiting the temperate and tropical-montane regions of North ...
or mixed oak forests with
ash Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non- gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...
and beech). Humid terrains were generally occupied by
alder Alders are trees comprising the genus ''Alnus'' in the birch family Betulaceae. The genus comprises about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few sp ...
and ash. The mixed oak forests lasted until the middle subatlantic (pollen zone IX b), which also had a wet but somewhat milder climate. Interspersed within the middle subatlantic are peaks in the occurrence of
European beech ''Fagus sylvatica'', the European beech or common beech is a deciduous tree belonging to the beech family Fagaceae. Description ''Fagus sylvatica'' is a large tree, capable of reaching heights of up to tall and trunk diameter, though mor ...
and European hornbeam (mixed oak forests with beech or mixed oak forests with elm, hornbeam and beech). During the younger subatlantic (pollen zone X a), whose wet and temperate climate resembled already today's conditions, a mixed or an almost pure beech forest established itself. Anthropogenic influences (i. e. agricultural land uses, grazing and forestry) that date back to the
Bronze Age The Bronze Age is a historic period, lasting approximately from 3300 BC to 1200 BC, characterized by the use of bronze, the presence of writing in some areas, and other early features of urban civilization. The Bronze Age is the second pri ...
started to become dominant. The actual youngest subatlantic (pollen zone X b) with its wet and temperate climate shows a distinct
precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...
gradient with decreasing rainfall from west to east. Natural and indigenous forest communities were severely diminished and more and more replaced by artificially managed forest communities. In northwestern
Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
mixed oak forests take up 40% amongst the total tree pollen during the older subatlantic and are therefore dominant. Afterwards their count starts fluctuating and they are definitely receding during the younger subatlantic. The percentage of elms and limes as members of the mixed oak forests yet stayed constant. Alders receded from 30 to 10%.
Pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accep ...
trees were also receding but peaked during the youngest subatlantic due to forestry.
Hazel The hazel (''Corylus'') is a genus of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family Betulaceae,Germplasmgobills Information Network''Corylus''Rushforth, K. (1999). ...
(15%),
birch A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus ''Betula'' contains 30 ...
(5%) and
willow Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist s ...
(<1%) roughly kept their numbers. Significant was the spreading of beech (from 5 to 45%) and hornbeam (from 1 to 15%). According to H. M. Müller the spreading of beech was caused by an increase in humidity since 550 BC and later favoured by a decrease in human settlements during the migrations. Herbs like
cornflower ''Centaurea cyanus'', commonly known as cornflower or bachelor's button, is an annual flowering plant in the family Asteraceae native to Europe. In the past, it often grew as a weed in cornfields (in the broad sense of "corn", referring to Foo ...
,
atriplex ''Atriplex'' () is a plant genus of about 250 species, known by the common names of saltbush and orache (; also spelled orach). It belongs to the subfamily Chenopodioideae of the family Amaranthaceae ''s.l.''. The genus is quite variable and w ...
,
sorrel Sorrel (''Rumex acetosa''), also called common sorrel or garden sorrel, is a perennial herbaceous plant in the family Polygonaceae. Other names for sorrel include spinach dock and narrow-leaved dock ('dock' being a common name for the genus '' ...
and
plantago ''Plantago'' is a genus of about 200 species of flowering plants in the family Plantaginaceae, commonly called plantains or fleaworts. The common name plantain is shared with the unrelated cooking plantain. Most are herbaceous plants, though a ...
also show a pronounced rise from 15 to 65% amongst the total pollen.
Cereals A cereal is any grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, germ, and bran. Cereal grain crops are grown in greater quantities and provide more food en ...
were also on the increase – they augmented from 5 to 30% and clearly document an expanding agriculture during the younger subatlantic. In northern Germany (
Ostholstein Ostholstein (; da, Østholsten) is a district in Schleswig-Holstein, Germany. It is bounded by (from the southwest and clockwise) the districts of Stormarn, Segeberg and Plön, the Baltic Sea and the city of Lübeck. History The district was es ...
) the vegetational evolution was very similar. Remarkable here is the rapid rise of non-tree pollen from 30 to more than 80% (including an increase in cereals from 2 to over 20%) during the younger subatlantic. Amongst the tree pollen the mixed oak forest was able to keep its share of 30%. Alders were also retreating from 40 to 25%. Let alone small fluctuations birch, beech and hornbeam overall conserved their share (hornbeam showed a distinct peak at the beginning younger subatlantic). Pine trees were also augmenting during the youngest subatlantic. Several distinct events could be recognized (from young to old): * spreading of pine trees (K) – at about 1800due to forestry * second beech peak (F 2) * first beech peak (F 1) – at about 1300 AD, in
Lower Saxony Lower Saxony (german: Niedersachsen ; nds, Neddersassen; stq, Läichsaksen) is a German state (') in northwestern Germany. It is the second-largest state by land area, with , and fourth-largest in population (8 million in 2021) among the 16 ...
already at about 800 AD. * fifth hazel peak (C 5) – at about 200 to 400 ADdue to climatic reasons


Fauna and flora

Fauna Fauna is all of the animal life present in a particular region or time. The corresponding term for plants is ''flora'', and for fungi, it is '' funga''. Flora, fauna, funga and other forms of life are collectively referred to as '' biota''. Zoo ...
l diversity has severely suffered since the middle of the 19th century by forced
industrialisation Industrialisation ( alternatively spelled industrialization) is the period of social and economic change that transforms a human group from an agrarian society into an industrial society. This involves an extensive re-organisation of an econo ...
and the concomitant
pollution Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...
of the environment. This trend has reached alarming proportions since 1975. According to the Living Planet Index
vertebrates Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, ...
have so far suffered a loss of 40% of their species.
Freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...
taxa have even been more severely affected – they have lost up to 50%, mainly due to biotope loss and water pollution. According to NASA, agriculture, fisheries and ecosystems will be increasingly compromised in the Northeastern United States. In the Southeastern United States, increasing wildfires, insect outbreaks and tree diseases are causing widespread tree die-off.


See also

*
Anthropocene The Anthropocene ( ) is a proposed geological epoch dating from the commencement of significant human impact on Earth's geology and ecosystems, including, but not limited to, anthropogenic climate change. , neither the International Commissi ...


References

{{DEFAULTSORT:Subatlantic .05 Geological ages Paleoclimatology Stratigraphy