PAGES Poland

paleolimnology

Lake sediments are excellent archives of palaeoenvironmental information.

Data on past environments to be obtained from lake sediments include:
- climate changes (temperature, humidity)
- palaeovegetation on the regional and local scale
- changes in trophic status, oxygenation and salinity of lake waters
- the magnitude of chemical and physical denudation

With respect to hydrologic regime lakes can be classified into three groups:

a) reservoir lakes - characterized by large surface relative to the catchment area and large basin volume; these lakes reveal only minor climate-induced variations in water level but, on the other hand, can often have several meters of sediment cover.

b) amtosphere controlled lakes - hydrologically opened, the main component of its hydrologic balance is runoff from the catchment and output from the lake, while the influence of precipitation and evaporation on lake level is negligible.

c) amplifier lakes - as opposed to reservoir lakes they are distinguished by relatively small ratio of lake/catchment areas; they usually are terminal lakes and display shallow depth; their hydrologic regime is mainly influenced by local precipitation and evaporation. Consequently, temporal changes in humidity of climate strongly affect the lake volume and its spatial extent.

Particularly valuable for palaeoenvironmental reconstructions are amplifier and reservoir lakes. In the former case, the record of environmental changes can be obtained from fossil shore forms of different age (lake terraces, shore ridges) (Langbein, 1961; Dury, 1973), and in the latter, high resolution information on past climate, hydrology and ecology are preserved in the undisturbed, annualy laminated sediments.


Over the territory of Poland amplifier lakes have not yet been identified. Most of lakes display reservoir and atmosphere controlled patterns.
Lacustrine sediments within different regions of Poland commonly include various types of organic-rich gyttjas and calcerous-detrital deposits (Wieckowski, 1978). Their deposition commenced during different times (Late-glacial to Holocene) in different environmental settings.

Lake deposits are the most important archive for palaeoclimate studies in Poland. Gościąż and Perespilno Lakes, for example, have received international status. Holocene peat deposits, which are common in Poland, are also valuable archives for the study of climate change. Comparisons of the fluctuations of the 14C content in raised bog deposits with the changing species composition of the peat-forming plants shows—like the above-mentioned lake level record—that changing solar activity has played an important role in the Holocene history of the region.


Despite the fact that several Polish lakes have been investigated with respect to Holocene environemtal changes (Niewiarowski 1978; Jankowska, 1980; Hjermroos-Ericsson, M., 1981, Bałaga, 1990; Tobolski, 1991, Niewiarowski et al., 1995, Wojciechowski, 1995, 2000 Marciniak, 1998, Ralska-Jasiewiczowa et al., 1998, Goslar et al., 1999, Milecka, Szeroczyńska, 2005, Bechtel et al., in press) (Fig. 1), only two of them, to date, have recovered high resolution palaeoclimatic and palaeohydrologic records for the last 13 000 years (Ralska-Jasiewiczowa et al., 1998, Goslar et al., 1999).

Michał Woszczyk

References
Bałaga, K. (1990). The development of Lake Łukcze and changes in the plant cover of the south-western part of the Łęczna Włodawa Lake Disrtict in the last 13000 years. Acta Palaeobotanica 30 (1,2), 77-146.
Bechtel, A., Woszczyk, M., Reischenbacher, D., Sachsenhofer, R.F., Gratzer, R., Püttmann, W., Spychalski, W. (in press): Biomarkers and geochemical indicators of Holocene environmental changes in coastal Lake Sarbsko (Poland). Org. Geochem., in press.
Borówka, R.K., Witkowski, A., Tomkowiak, J., Olas, M., Gusar, K., Liszkiewicz, E. (1999). Stratygraficzna i przestrzenna zmienność litologiczna i geochemiczna osadów wypełniających Zalew Szczeciński i baseny przyległe. In: Borówka, R.K. et al. (Eds.) Ewolucja geosystemów nadmorskich południowego Bałtyku. Bogucki Wyd. Nauk., Poznań-Szczecin, 55-62.
Dury, G.H. (1973). Paleohydrologic implications of some pluvial lakes in northwestern New South Wales, Australia. Geol. Soc. of Am. Bulletin, 84, 3663-3676.
Goslar, T., Balaga, K., Arnold, M., Tisnerat, N., Starnawska, E., Kuzniarski, M., Chrost, L., Walanus, A., Wieckowski, K. (1999): Climate-related variations in the compositon of the Lateglacial and Early Holocene sediments of Lake Perespilno (eastern Poland). Quart. Sci. Res. 18, 899-911.
Hjelmroos-Ericson, M. (1981): Holocene development of lake Wielkie Gacno area, northwestern Poland. Thesis 10, University of Lund, 101 pp.
Jankowska, B. (1980). Szata roślinna okolic Gopła w późnym glacjale i holocenie oraz wpływ osadnictwa na jej rozwój w świetle badań paleobotanicznych. Przegl. Archeol. Vol. 27, 5-41.
Langbein, W. (1961). Salinity and hydrology of closed lakes. US Geol. Survey. Prof. Paper 412, 1-20.
Marciniak, B. (1998): The diatom record of Holocene lake-level changes in the central part of the Polish Lowland, In: Frenzel, B. et al. (Publ.), Palaeohydrology as reflected in lake-level changes as climatic evidence for Holocene times, Palaeoclimate Research 25, 53-66.
Milecka K., Szeroczyńska K. (2005): Changes in macrophytic flora and planktonic organisms in lake Ostrowite, Poland as a response of climatic and trophy fluctuations. The Holocene 15, 74-84.
Niewiarowski, W. (1978): Fluctuations of water-level in the Goplo Lake and their reasons. Pol. Arch. Hydrobiol. 25, 301-306.
Niewiarowski, W. (1987). Development of Lake Strażym (Brodnica Lake District) during the late-glacial and holocene. Acta Palaeobotanica 27(1), 251-268.
Niewiarowski, W., Noryśkiewicz, B., Piotrowski, W., Sinkiewicz, M. (1995): An outline of natural and anthropogenic changes of geographical environment in the Biskupin area during the last 7000 years. Quaternary Studies in Poland 13, 77-88.
Ralska-Jasiewiczowa, M., Goslar, T., Madeyska, T., Starkel, L. (Eds.) (1999): Lake Gościąż, Central Poland: A monographic study. Szafer Institute of Botany, Polish Academy of Sciences, Kraków, 340 pp.
Tobolski, K. (1991): Wstęp do paleoekologii Lednickiego Parku Krajobrazowego. Wyd. Nauk. UAM, Poznań, 157 pp.
Wieckowski, K., (1978): Bottom deposits in lakes of different regions of Poland (their characteristics, thickness and rates of accumulation).  Pol. Arch. Hydrobiol. 25, 483-489.
Wojciechowski, A. (1990). Analiza litofacjalna osadów jeziora Gardno. Wyd. Nauk. UAM, 118 pp.
Wojciechowski, A. (2000). Zmiany paleohydrologiczne w środkowej Wielkopolsce w ciągu ostatnich 12000 lat w świetle badań osadów jeziornych rynny kórnicko-zaniemyskiej. Wyd. Nauk. UAM, Poznań, 236 pp.