Stratigraphy and dating of a lake sediment record from Lyngsjön, eastern Scania : human impact and aeolian sand deposition during the last millennium
(2019) In Dissertations in Geology at Lund University GEOR02 20162Department of Geology
- Abstract
- A small lake in north-eastern Scania, southern Sweden, Lake Lyngsjön, reveals a long history of aeolian sand drift based on a 3 meter long sediment sequence covering the last approximately 1400 years. Human impact, primarily through intensified land use and decreased forest cover, has periodically led to increased aeolian sand drift both locally and regionally. Elevated C/N ratios suggest a period of increased forest cover close to the lake as seen primarily through elevated pine pollen frequencies during the 10th century and later during the 18th century. Agricultural changes such as the 19th century land amalgamation, which would have led to enhanced wind erosion of fields, was simultaneously countered through the plantation of trees,... (More)
- A small lake in north-eastern Scania, southern Sweden, Lake Lyngsjön, reveals a long history of aeolian sand drift based on a 3 meter long sediment sequence covering the last approximately 1400 years. Human impact, primarily through intensified land use and decreased forest cover, has periodically led to increased aeolian sand drift both locally and regionally. Elevated C/N ratios suggest a period of increased forest cover close to the lake as seen primarily through elevated pine pollen frequencies during the 10th century and later during the 18th century. Agricultural changes such as the 19th century land amalgamation, which would have led to enhanced wind erosion of fields, was simultaneously countered through the plantation of trees, which hampered transportation of aeolian sand into the lake. The continuation of intensified agricultural activity after the implementation of land amalgamation successively led to increased deposition of aeolian sand during the onset of the 20th century. Organic and carbonate contents of the sediments are generally anti-correlated for the majority of the succession although changes in land use during the past 100 years, with substantial input of aeolian sand around the 1920s, seem to have had a major impact on the total inorganic carbon (TIC) signal; possibly by a reduction in carbonate producing algae. Later agricultural changes during the 1940s did not have any major effects on the lake since the plantation of pine and spruce in proximity of the lake acted as a shelter for aeolian sand drift. Correlations between the reconstructed aeolian sand content within the more recent part of the succession and documented historical events have been used to explain earlier aeolian sand deposition events during the 10th and 12th century. A continuous record of cultivated pollen points towards an uninterrupted human influence having an effect on the lake sediments during the past millennium. Maps from the 17th century and onwards reveal a close relationship between past aeolian sand deposition and changes in forest extent on a local to regional scale. (Less)
- Abstract (Swedish)
- En liten sjö, Lyngsjön, i nordöstra Skåne, södra Sverige, avslöjar en lång historia av eolisk aktivitet baserat på en 3 meter lång sedimentsekvens som omfattar de senaste 1400 åren. Mänsklig inverkan, främst genom intensifierad markanvändning och minskad utbredning av skog, har lett till ökad eolisk sand drift både lokalt och regionalt. En ökning i C/N förhållanden tyder på en period med ökad utbredning av skog i närheten av sjön som även kan ses genom en ökning i tallpollenförekomster under 900-talet samt senare under 1700-talet. Jordbruksförändringar så som 1800-talets landändringsreformer som borde ha inneburit en ökning i vinderosion av jordbruksmarker, motverkades istället av en samtida plantering av träd vilket hindrade transporten... (More)
- En liten sjö, Lyngsjön, i nordöstra Skåne, södra Sverige, avslöjar en lång historia av eolisk aktivitet baserat på en 3 meter lång sedimentsekvens som omfattar de senaste 1400 åren. Mänsklig inverkan, främst genom intensifierad markanvändning och minskad utbredning av skog, har lett till ökad eolisk sand drift både lokalt och regionalt. En ökning i C/N förhållanden tyder på en period med ökad utbredning av skog i närheten av sjön som även kan ses genom en ökning i tallpollenförekomster under 900-talet samt senare under 1700-talet. Jordbruksförändringar så som 1800-talets landändringsreformer som borde ha inneburit en ökning i vinderosion av jordbruksmarker, motverkades istället av en samtida plantering av träd vilket hindrade transporten av eolisk sand till sjön. Den fortsatta påtagliga jordbruksverksamheten efter sammanslagningen av jordbruksenheter (s.k. enskiftet) ledde successivt till ökad deposition av eolisk sand i början av 1900-talet. Mängden organiskt material samt mängden karbonater i sedimenten visar på en generell anti-korrelation genom majoriteten av sedimentsuccessionen, dock inte under de senaste 100 åren då en betydande mängd sand avsattes under 1920-talet vilket verkar ha påverkat den totala mängden oorganiskt kol; möjligtvis genom en minskning av karbonatproducerande alger. Jordbruksförändringar under 1940-talet och framåt verkar inte ha haft en stor inverkan på sjön. Detta främst i samband med att det planterades träd (tall och gran) i närheten av sjön vilket fungerade som ett skydd mot inkommande eolisk sand till sjön. Jämförelser mellan rekonstruerad mängd eolisk sand för de mer recenta delarna av successionen och dokumenterade historiska händelser, användes för att kunna förklara tidigare deposition av eolisk sand under 900-talet samt 1100-talet. En kontinuerlig förekomst av pollen från odlade växter tyder på en oavbruten påverkan av sjösedimenten till följd av mänsklig aktivitet under det senaste milleniet. Kartor från 1600-talet framåt visar på en nära koppling mellan historisk deposition av eolisk sand och ändringar i utbredning av skog både lokalt och regionalt. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/8969134
- author
- Stevic, Marijana LU
- supervisor
-
- Dan Hammarlund LU
- Karl Ljung LU
- organization
- course
- GEOR02 20162
- year
- 2019
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- aeolian activity, human impact, geochemistry, lake sediments, pollen
- publication/series
- Dissertations in Geology at Lund University
- report number
- 555
- language
- English
- id
- 8969134
- date added to LUP
- 2019-02-01 10:46:10
- date last changed
- 2019-02-01 10:46:10
@misc{8969134,
abstract = {{A small lake in north-eastern Scania, southern Sweden, Lake Lyngsjön, reveals a long history of aeolian sand drift based on a 3 meter long sediment sequence covering the last approximately 1400 years. Human impact, primarily through intensified land use and decreased forest cover, has periodically led to increased aeolian sand drift both locally and regionally. Elevated C/N ratios suggest a period of increased forest cover close to the lake as seen primarily through elevated pine pollen frequencies during the 10th century and later during the 18th century. Agricultural changes such as the 19th century land amalgamation, which would have led to enhanced wind erosion of fields, was simultaneously countered through the plantation of trees, which hampered transportation of aeolian sand into the lake. The continuation of intensified agricultural activity after the implementation of land amalgamation successively led to increased deposition of aeolian sand during the onset of the 20th century. Organic and carbonate contents of the sediments are generally anti-correlated for the majority of the succession although changes in land use during the past 100 years, with substantial input of aeolian sand around the 1920s, seem to have had a major impact on the total inorganic carbon (TIC) signal; possibly by a reduction in carbonate producing algae. Later agricultural changes during the 1940s did not have any major effects on the lake since the plantation of pine and spruce in proximity of the lake acted as a shelter for aeolian sand drift. Correlations between the reconstructed aeolian sand content within the more recent part of the succession and documented historical events have been used to explain earlier aeolian sand deposition events during the 10th and 12th century. A continuous record of cultivated pollen points towards an uninterrupted human influence having an effect on the lake sediments during the past millennium. Maps from the 17th century and onwards reveal a close relationship between past aeolian sand deposition and changes in forest extent on a local to regional scale.}},
author = {{Stevic, Marijana}},
language = {{eng}},
note = {{Student Paper}},
series = {{Dissertations in Geology at Lund University}},
title = {{Stratigraphy and dating of a lake sediment record from Lyngsjön, eastern Scania : human impact and aeolian sand deposition during the last millennium}},
year = {{2019}},
}