- Stora Alvaret
Infobox World Heritage Site
WHS = Agricultural Landscape of Southern Öland
State Party = SWE
Type = Cultural
Criteria = iv, v
ID = 968
Region = Europe and North America
Year = 2000
Session = 24th
Link = http://whc.unesco.org/en/list/968The Stora Alvaret is a limestone barren plain on the island of
Öland ,Sweden . Because of the thin soil mantle and highpH levels, a great assortment of vegetation is found including numerousrare species . Stora Alvaret has been designated as aWorld Heritage Site byUNESCO due to its extraordinarybiodiversity and prehistory. The area of this formation exceeds 260 km², making it the largest such expanse inEurope and comprising over one fourth of the land area of the island. Stora Alvaret is not devoid of trees, contrary to a common misconception; in fact, it holds a variety of sparse stunted trees akin to apygmy forest [Hakan Sandbring and Martin Borg, "Oland: Island of Stone and Green", May, 1997] . The Stora Alvaret, sometimes called the Great Alvar, is adagger shaped expanse almost 40 kilometers long and about 10 kilometers at the widest {north end}.Geological origins
The limestone plain was created by glacial action from earlier ice age advances. The limestone formation itself was created about 500 million years ago in more southerly seas. Gradually hardening into limestone and drifting northward, the limestone of the Stora Alvaret contains a rich fossil record of some of the marine creatures who contributed to it [Thorsten Jansson, "Stora Alvaret", Lenanders Tryckeri,
Kalmar , 1999] . For example,orthoceratites are found in some of the present day structures on the island.Only as recently as 11,000 years ago did the first portions of the island of Öland emerge from the
Baltic Sea , after the overpressure of the last glaciers was relieved by melting. Over the next several thousand years, more ice melted and the first wave of largemammal s includinghuman s migrated across theice bridge from the mainland. Finally a thinsoil mantle (only two centimeters at the deepest) was formed by plant colonisation of the barelimestone and some wind driven deposition, to create thealvar formation of the present. In many places the limestone has no soil whatsoever upon it.Prehistoric man
The best known early paleolithic settlement occurs at Alby, situated on the east coast of the island, where excavations have revealed vestiges of wooden huts around a prehistoric
lagoon . Artefacts retrieved include evidence ofbear ,marten , seal andporpoise , but also reveal hunting and gathering technologies through discovery ofbone spear s, elkantler harpoon s andflint .Evidence of later
ringfort s abounds including the most well known site atEketorp . In theBronze Age and early part of theIron Age , extreme pressure was exerted on the limited tree species growing on the Stora Alvaret and its margins. Jannson suggests that this disappearance of trees caused a mysterious evaporation of humans about 500 AD which is documented at Eketorp [K. Borg, U. Näsman, E. Wegraeus, "The Excavation of the Eketorp Ring-fort 1964-74". In "Eketorp Fortifikation and Settlement on Öland, Sweden", 1976] and other sites. It is thought provoking to imagine that the expanded human population may have exceeded itscarrying capacity of this place by about 500 AD. Later, about 800 to 1000 AD variousViking settlements appeared on the fringe of the Stora Alvaret.Ecology
The first documented scientific study of the
biota of the Stora Alvaret occurred in the year 1741 with the visit ofLinnaeus [Carl Linnaeus, "Öländska och Gothländska resa", Stockholm, Sweden (1745)] . He wrote of this unusual ecosystem: "It is noteworthy how some plants are able to thrive on the driest and most barren places of the alvar". Somerelict species from the glacial age are among theflora palette of the Stora Alvaret. A wide variety ofwildflower s and other plants are found on the limestone pavement ecosystem. Some of the species found includestonecrop ,dropwort , "Artemisia oelandica" (endemic to Öland),Shrubby Cinquefoil ,Common spotted orchid and kidneyvetch [C. M. Hogan, "The Stora Alvaret of Öland", Lumina Technologies, Aberdeen Library Archives, July 9, 2006] . Most of these wildflowers bloom from May to July.Numerous grasses are found on this alvar including Meadow Oat-grass and
Sheep's Fescue ; as would be expected from the occurrence of orchids, manyfungi grow on the Stora Alvaret such as "Hygrocybe persistens" and "Lepiota alba". Although the alvar here is known for its severely dry conditions, there are some seasonal wetlands andvernal pool s, notably the vestigiallagoon area northwest of thevillage of Alby.Practical logistics
The Stora Alvaret is bounded on the east, west and south by the
perimeter public two-lanehighway which circumnavigates the entire island. At several latitudes there are less improved roadways that run east-west and intrude directly through the Stora Alvaret. Small villages such as Stora Vickleby, Gettlinge, Grönhögen, Hulterstad, Alby, Triberga and Vället lie at the fringe of the Stora Alvaret along the perimeter highway. There are fewer and smaller villages within the alvar expanse itself: Mockelmossen, Solberga and Flisas, for example. Some of the old villages are totally deserted such as Dröstorp. At the extreme south end of the Stora Alvaret liesOttenby , a historic royal game farm and now anature reserve .References
ee also
*
Eketorp
*Stone Age
*Windmill
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