Studies of four sediment cores from the littoral zone of a small Lake Verevi with a well-established history of lake hydrochemistry and hydrobiology were conducted. Observational data describe essential changes in the composition of macrophytes and the trophic state of the lake during the last century. Lithological composition (organic, siliciclastic, and carbonaceous matter) in the four sediment profiles taken within a distance of 20 m showed good lithostratigraphical correspondence but differences (up to two times) in the mass accumulation rates of various compounds. Most of the organic matter (75–85%) in the sediment originates from phytoplankton as demonstrated by low organic carbon/nitrogen ratios. Accumulation of organic matter is not directly related to changes in lake trophicity and primary production but rather seems to be dependent on the accumulation of siliciclastic matter, which engages the organic matter in the settling processes. This is supported by the extremely high correlations between the mass accumulation rates of siliciclastic and organic matter (R2 > 0.8). Although the greatest changes in the lake environment took place after 1970 due to severe human impact on the lake, most of the changes in the sediment records started earlier. Precipitation of CaCO3 began already in the 1930s due to natural eutrophication processes and reached its highest values in the 1970s, which can be related to the anthropogenic impact. Also the share of carbon from algae, indicating a rise in the trophic status, started to increase in the 1930s. Macrofossil records reveal that also major changes in the vegetation may have started earlier than historically recorded. The rise in the trophic status of the lake had no direct effect on the accumulation of organic matter.
Appleby, P. G., Nolan, P. J., Gifford, D. W., Godfrey, M. J., Oldfield, F., Anderson, N. J. & Battarbee, R. W. 1986. 210Pb dating by low background gamma counting. Hydrobiologia, 141, 21–27.
http://dx.doi.org/10.1007/BF00026640
Barko, J. W., Gunnison, D. & Carpenter, S. R. 1991. Sediment interactions with submersed macrophyte growth and community dynamics. Aquat. Bot., 41, 41–65.
http://dx.doi.org/10.1016/0304-3770(91)90038-7
Boyle, J. F. 2001. Inorganic geochemical methods in paleolimnology. In Tracking Environmental Change Using Lake Sediments. Vol. 2. Physical and Geochemical Methods (Last, W. M. & Smol, J. P., eds), pp. 83–142. Kluwer Academic Publishers, Dordrecht.
Davidson, T. A., Sayer, C. D., Bennion, H., David, C., Rose, N. & Wade, M. P. 2005. A 250 year comparison of historical, macrofossil and pollen records of aquatic plants in a shallow lake. Freshwater Biol., 50, 1671–1684.
Dean, W. E. 1999. The carbon cycle and biogeochemical dynamics in lake sediments. J. Paleolimnol., 21, 375–393.
http://dx.doi.org/10.1023/A:1008066118210
Ekdahl, E. J., Teranes, J. L., Guilderson, T. P., Turton, C. L., McAndrews, J. H., Wittkop, C. A. & Stoermer, E. F. 2004. Prehistorical record of cultural eutrophication from Crawford Lake, Canada. Geology, 32, 745–748.
http://dx.doi.org/10.1130/G20496.1
Gaillard, M.-J. & Digerfeldt, G. 1991. Palaeohydrological studies and their contribution to palaeoecological and palaeoclimatic reconstructions. Ecol. Bull., 41, 275–282.
Hannon, G. E. & Gaillard, M.-J. 1997. The plant macrofossil record of past lake-level changes.
J. Paleolimnol., 18, 15–28.
http://dx.doi.org/10.1023/A:1007958511729
Heiri, O., Lotter, A. F. & Lemcke, M.-J. 2001. Loss on ignition as a method for estimating organic and carbonate content in sediments: reproducibility and comparability of results. J. Paleolimnol., 25, 101–110.
http://dx.doi.org/10.1023/A:1008119611481
Ho, E. S. & Meyers, P. A. 1994. Variability of early diagenesis in lake sediments: evidence from the sedimentary geolipid record in an isolated tarn. Chem. Geol., 112, 309–324.
http://dx.doi.org/10.1016/0009-2541(94)90031-0
Horppila, J. & Nurminen, L. 2001. The effect of an emergent macrophyte (Typha angustifolia) on sediment resuspension in a shallow north temperate lake. Freshwater Biol., 48, 1447–1455.
http://dx.doi.org/10.1046/j.1365-2427.2001.00765.x
Kim, J.-W., Furukawa, Y., Dong, H. & Newell, S. 2005. The effect of microbial Fe(III) reduction on smectite flocculation. Clays Clay. Miner., 53, 572–579.
http://dx.doi.org/10.1346/CCMN.2005.0530603
Kuehn, K. A., Gessner, M., Wetzel, R. & Suberkropp, K. 1999. Decomposition and CO2 evolution from standing litter of the emergent macrophyte Erianthus giganteus. Microb. Ecol., 38, 50–57.
http://dx.doi.org/10.1007/s002489900154
Last, W. M. & Smol, J. P. (eds). 2001. Tracking Environmental Change Using Lake Sediments. Volume 2: Physical and Geochemical Methods. Kluwer Academic Publishers, Dordrecht.
Madsen, J. D., Chambers, P. A., James, W. F., Koch, E. W. & Westlake, D. F. 2001. The interactions between water movement, sediment dynamics and submersed macrophytes. Hydrobiologia, 444, 71–84.
http://dx.doi.org/10.1023/A:1017520800568
Mäemets, A. 1991. Suurtaimestik. In Verevi järve seisund. Hüdrobioloogilised Uurimused 17 (Timm, H., ed.), pp 95–109. Estonian Academy of Sciences, Institute of Zoology and Botany, Tartu.
Mäemets, H. & Freiberg, L. 2005. Long- and short-term changes of the macrophyte vegetation in strongly stratified hypertrophic Lake Verevi. Hydrobiologia, 547, 175–184.
Menounos, B. 1997. The water content of lake sediments and its relationship to other physical parameters: an alpine case study. Holocene, 7, 207–212.
http://dx.doi.org/10.1177/095968369700700208
Meyers, P. A. 1994. Preservation of elemental and isotopic source identification of sedimentary organic matter. Chem. Geol., 114, 289–302.
http://dx.doi.org/10.1016/0009-2541(94)90059-0
Meyers, P. A. 2006. An overview of sediment organic matter records of human eutrophication in the Laurentian Great Lakes region. Water Air Soil Pollut. Focus, 6, 453–463.
http://dx.doi.org/10.1007/s11267-006-9059-9
Moser, K. A., Smol, J. P., MacDonald, G. M. & Larsen, C. P. S. 2002. 19th century eutrophication of a remote boreal lake: a consequence of climate warming? J. Paleolimnol., 28, 269–281.
http://dx.doi.org/10.1023/A:1021635024757
Ott, I., Kõiv, T., Nõges, P., Kisand, A., Järvalt, A. & Kirt, E. 2005. General description of partly meromictic hypertrophic Lake Verevi, its ecological status, changes during the past eight decades, and restoration problems. Hydrobiologia, 547, 1–20.
http://dx.doi.org/10.1007/1-4020-4363-5_1
Punning, J.-M. & Tõugu, K. 2000. C/N ratio and fossil pigments in sediments of some Estonian lakes: an evidence of human impact and Holocene environmental change. Environ. Monit. Assess., 64, 549–567.
http://dx.doi.org/10.1023/A:1006325606289
Punning, J.-M., Koff, T., Sakson, M. & Terasmaa, J. 2004. Human impact on the ecosystem of Lake Ruusmäe (Southern Estonia) traced in its sediments. Pol. J. Ecol., 52, 285–299.
Punning, J.-M., Koff, T., Kadastik, E. & Mikomägi, A. 2005. Holocene lake level fluctuations recorded in the sediment composition of Lake Juusa, southeastern Estonia. J. Paleolimnol., 34, 377–390.
http://dx.doi.org/10.1007/s10933-005-6751-0
Roberts, J., Jepsen, R., Gotthard, D. & Lick, W. 1998. Effects of particle size and bulk density on erosion of quartz particles. J. Hydraul. Eng.-ASCE, 124, 1261–1267.
http://dx.doi.org/10.1061/(ASCE)0733-9429(1998)124:12(1261)
Vallentyne, J. R. 1955. A modification of the Livingstone piston sampler for lake deposits. Ecology, 36, 139–141.
http://dx.doi.org/10.2307/1931440
Van Rijn, L. 1993. Principles of Sediment Transport in Rivers, Estuaries, and Coastal Seas. Aqua, Amsterdam.
Vreca, P. & Muri, G. 2006. Changes in accumulation of organic matter and stable carbon and nitrogen isotopes in sediments of two Slovenian mountain lakes (Lake Ledvica and Lake Planina), induced by eutrophication changes. Limnol. Oceanogr., 51, 781–790.
http://dx.doi.org/10.4319/lo.2006.51.1_part_2.0781
http://dx.doi.org/10.1007/978-1-4020-6158-5_13
