Vesikirput kahden Kilpisjärven alueen järven viimeaikaisen kehityksen kuvaajina
In this thesis I used paleolimnological methods to study changes in two lakes in Kilpisjärvi region, Somas and Vallijärvi, during the last c. 400 years. I examined the remains of cladocera preserved in sediments to find out species composition and population size in the past. The objective of this s...
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Helsingfors universitet
2005
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Online Access: | http://hdl.handle.net/10138/18889 |
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ftunivhelsihelda:oai:helda.helsinki.fi:10138/18889 2023-08-20T04:07:46+02:00 Vesikirput kahden Kilpisjärven alueen järven viimeaikaisen kehityksen kuvaajina Cladocera as indicators of resent changes in two lakes in Kilpisjärvi region Siitonen, Susanna Helsingin yliopisto, Bio- ja ympäristötieteellinen tiedekunta, Bio- ja ympäristötieteiden laitos University of Helsinki, Faculty of Biological and Environmental Sciences, Department of Biological and Environmental Sciences Helsingfors universitet, Bio- och miljövetenskapliga fakulteten, Institutionen för bio- och miljövetenskaper 2005 application/pdf http://hdl.handle.net/10138/18889 fin fin Helsingfors universitet University of Helsinki Helsingin yliopisto URN:NBN:fi-fe200805091362 http://hdl.handle.net/10138/18889 Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden. This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited. Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty. Aquatic Sciences Akvaattiset tieteet Akvatiska vetenskape pro gradu-avhandlingar pro gradu -tutkielmat master's thesis 2005 ftunivhelsihelda 2023-07-28T06:10:58Z In this thesis I used paleolimnological methods to study changes in two lakes in Kilpisjärvi region, Somas and Vallijärvi, during the last c. 400 years. I examined the remains of cladocera preserved in sediments to find out species composition and population size in the past. The objective of this study is to reveal if the cladoceran species compositions have changed in the lakes and what is has been driving these changes. In addition, I will use cladoceran resting eggs from the sediment of lake Somas to examine the applicability of resting eggs as a new paleolimnological method. In April 2002 I cored sediment sequences from the lakes and sliced them into 0,5-1 cm subsamples. The samples were dated with led isotope, 210Pb, to reveal the sedimentation rate. From the sediments I determined the organic carbon content, counted the proportions of different cladoceran species, the absolute numbers of individuals and the yearly accumulation of cladocera to the sediment. In addition I calculated the relative share of resting eggs. I examined relationships between the samples and between the samples and measured environmental variables with a set of multivariate methods (DCA, DCCA, PCA, RDA). I tested a previously created cladoceran-water depth model to Vallijärvi data in order to reconstruct past water level development in the lake. In the turn of the last century a distinct interface between two different species compositions can be seen in both lakes. Also the accumulation of cladocera into the sediments has increased in both lakes, and the planktic species have out paced the littoral ones during the last century indicating an increase in productivity. Also sedimentological processes have develop similarly in the lakes. Due to the location of the lakes, their differing morphology and history the changes in biological and sedimentological processes have been stronger in the lake Vallijärvi. The model on past water levels seemed to perform well in the lake Vallijärvi. Water level reconstruction was not, however, problem ... Master Thesis Kilpisjärvi Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto Kilpisjärvi ENVELOPE(20.767,20.767,69.034,69.034) |
institution |
Open Polar |
collection |
Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto |
op_collection_id |
ftunivhelsihelda |
language |
Finnish |
topic |
Aquatic Sciences Akvaattiset tieteet Akvatiska vetenskape |
spellingShingle |
Aquatic Sciences Akvaattiset tieteet Akvatiska vetenskape Siitonen, Susanna Vesikirput kahden Kilpisjärven alueen järven viimeaikaisen kehityksen kuvaajina |
topic_facet |
Aquatic Sciences Akvaattiset tieteet Akvatiska vetenskape |
description |
In this thesis I used paleolimnological methods to study changes in two lakes in Kilpisjärvi region, Somas and Vallijärvi, during the last c. 400 years. I examined the remains of cladocera preserved in sediments to find out species composition and population size in the past. The objective of this study is to reveal if the cladoceran species compositions have changed in the lakes and what is has been driving these changes. In addition, I will use cladoceran resting eggs from the sediment of lake Somas to examine the applicability of resting eggs as a new paleolimnological method. In April 2002 I cored sediment sequences from the lakes and sliced them into 0,5-1 cm subsamples. The samples were dated with led isotope, 210Pb, to reveal the sedimentation rate. From the sediments I determined the organic carbon content, counted the proportions of different cladoceran species, the absolute numbers of individuals and the yearly accumulation of cladocera to the sediment. In addition I calculated the relative share of resting eggs. I examined relationships between the samples and between the samples and measured environmental variables with a set of multivariate methods (DCA, DCCA, PCA, RDA). I tested a previously created cladoceran-water depth model to Vallijärvi data in order to reconstruct past water level development in the lake. In the turn of the last century a distinct interface between two different species compositions can be seen in both lakes. Also the accumulation of cladocera into the sediments has increased in both lakes, and the planktic species have out paced the littoral ones during the last century indicating an increase in productivity. Also sedimentological processes have develop similarly in the lakes. Due to the location of the lakes, their differing morphology and history the changes in biological and sedimentological processes have been stronger in the lake Vallijärvi. The model on past water levels seemed to perform well in the lake Vallijärvi. Water level reconstruction was not, however, problem ... |
author2 |
Helsingin yliopisto, Bio- ja ympäristötieteellinen tiedekunta, Bio- ja ympäristötieteiden laitos University of Helsinki, Faculty of Biological and Environmental Sciences, Department of Biological and Environmental Sciences Helsingfors universitet, Bio- och miljövetenskapliga fakulteten, Institutionen för bio- och miljövetenskaper |
format |
Master Thesis |
author |
Siitonen, Susanna |
author_facet |
Siitonen, Susanna |
author_sort |
Siitonen, Susanna |
title |
Vesikirput kahden Kilpisjärven alueen järven viimeaikaisen kehityksen kuvaajina |
title_short |
Vesikirput kahden Kilpisjärven alueen järven viimeaikaisen kehityksen kuvaajina |
title_full |
Vesikirput kahden Kilpisjärven alueen järven viimeaikaisen kehityksen kuvaajina |
title_fullStr |
Vesikirput kahden Kilpisjärven alueen järven viimeaikaisen kehityksen kuvaajina |
title_full_unstemmed |
Vesikirput kahden Kilpisjärven alueen järven viimeaikaisen kehityksen kuvaajina |
title_sort |
vesikirput kahden kilpisjärven alueen järven viimeaikaisen kehityksen kuvaajina |
publisher |
Helsingfors universitet |
publishDate |
2005 |
url |
http://hdl.handle.net/10138/18889 |
long_lat |
ENVELOPE(20.767,20.767,69.034,69.034) |
geographic |
Kilpisjärvi |
geographic_facet |
Kilpisjärvi |
genre |
Kilpisjärvi |
genre_facet |
Kilpisjärvi |
op_relation |
URN:NBN:fi-fe200805091362 http://hdl.handle.net/10138/18889 |
op_rights |
Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden. This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited. Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty. |
_version_ |
1774719633645895680 |