Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund PALEOLIMNOLOGICAL STUDIES...

Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund

PALEOLIMNOLOGICAL STUDIES IN THE WEL LAKES

Sigrid Haande, NIVADeWELopment workshop, Oslo 21.-22.06 2010


DeWELopment: OBJECTIVE

• Validation of reference conditions in selected lakes in the WEL catchment area by using paleolimnological methods

– Dating 210Pb

– Dry weight/Loss of ignition

– Algal pigments

– Diatoms


BACKGROUND

• Palaeolimnology provides powerful tools to determine reference conditions and to assess the deviation from reference conditions

• Analyse a number of slices from different levels of a sediment core, corresponding to different periods in the history of the lake

• the palaeo-record potentially allows the structural and functional characteristics of pre-pollution aquatic ecosystems to be reconstructed


THE WEL LAKES

Lakes Depths Sample approach

Dąbrowa Wielka 34.7 Top/BottomDąbrowa Mała 34.5 Top/BottomGrądy 9.1 Top/BottomTarczyńskie 9.2 Top/BottomZwiniarz 5.8 Top/BottomZarybinek 7 Top/BottomRumian 14.4 Whole coreHartowieckie 5.2 Top/BottomKiełpińskie 11 Whole coreLidzbarskie 25 Whole core


METHODS

Each slice was divided in four parts:

1. Dry weight and loss of ignition

2. Dating 210Pb (DHI, Denmark)

3. Pigment analyses (NIVA)

4. Diatom analysis (UCL, England)


METHODS: Diatom inferred-Total Phosphorous reconstructions

• Diatom analyses from each core

(25 sub samples from the full cores; top/bottom samples)

• A diatom-total phosphorous (TP) transfer function was applied to the diatom data for each core.

• A reconstruction of diatom-inferred total phosphorous (DI-TP) were produced by using a Northwest European training set of 152 relatively small, shallow lakes (<10 m max depth) with a median value of the dataset fo 104 µg TP L-1.


RESULTS: Lake Rumian

Lake Rumian

1980

1985

1990

1995

2000

2005

2010

0 100 200 300

Chl-a/allomers (µg/g DW)

Lake Rumian

1980

1985

1990

1995

2000

2005

2010

0 5 10 15

Zeaxanthin (µg/g DW)

Dating 210Pb Pigments

Lake Rumian

0

5

10

15

20

25

30

1980 1990 2000 2010 2020

Year

Dep

th(c

m)


RESULTS: Diatoms


RESULTS: Lake Lidzbaskie

Lake Lidzbarskie

1940

1950

1960

1970

1980

1990

2000

2010

0 100 200 300

Chl-a (µg/g DW)

Lake Lidzbarskie

1940

1950

1960

1970

1980

1990

2000

2010

0 5 10 15



Lake Lidzbarskie

0

5

10

15

20

25

30

35

40

1940 1960 1980 2000 2020

Year

Dep

th(c

m)


RESULTS: Diatom analyses


RESULTS: Lake Kielpinskie

Lake Kielpinskie

1890

1910

1930

1950

1970

1990

2010

0 50 100 150 200

Chl-a (µg/g DW)

Lake Kielpinskie

1890

1910

1930

1950

1970

1990

2010

0 2 4 6 8



Lake Kielpinskie

0

5

10

15

20

25

30

1850 1900 1950 2000 2050

Year

Dep

th(c

m)


RESULTS: Diatom analyses


RESULTS: Other WEL lakes

Lake Top/Bottom Samples

Lake Dabrowa Wielka Top Lake Dabrowa Wielka Bottom_30

Lake Dabrowa Mala Top Lake Dabrowa Mala Bottom_40

Lake Zarybinek Top Lake Zarybinek Bottom_30

Lake Tarczynskie Top Lake Tarczynskie Bottom_27

Lake Grady Top Lake Grady Bottom_30

Lake Hartowieckie Top Lake Hartowieckie Bottom_35

Lake Zwiniarz Top Lake Zwiniarz Bottom_30


RESULTS: Other lakes-Diatom analyses


RESULTS

WEL lakes 2009 Top Bottom Length of core Age TP (µg/L)* DI-TP (µg/L) DI-TP (µg/L) cm bottom sample

Dąbrowa Wielka 65 42 73 30 ?Dąbrowa Mała 54 62 100 40 ?Rumian 80 127 104 27 30Zarybinek 76 150 124 30 ?Grądy 84 212 154 30 ?Tarczyńskie 88 144 178 27 ?Lidzbarskie 72 149 92 36 60Kiełpińskie 66 93 75 29 120Hartowieckie 69 101 132 35 ?Zwiniarz 116 113 119 30 ?

* Mean value April-October 2009


SUMMARY

• All lakes have been nutrient rich • Pre-reference communities could not be defined for the three lakes• The sediment cores cover a relatively short period (30-120 years)

• Lake Rumian (30 years)

Nutrient rich for the whole period

May show some degree of recovery

• Lake Lidzbarskie (60 years)


Enrichment 1960-1990

Slight decrease in enrichment the last 10 years

• Lake Kielpinskie (120 years)


Enrichment in the early 1900,

Slight decline in productivity the last 10 years

• Other lakes, just indicative results


Date post:	16-Dec-2015
Category:	Documents
Upload:	holly-lamb
View:	214 times
Download:	1 times

Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund PALEOLIMNOLOGICAL STUDIES...

Documents