We examined spatial and temporal changes of the macrophyte species richness in Lake Peipsi by comparing the frequency of 76 taxa in earlier (1970 and 1980; 49 stations) and recent (1997–2014; 52 stations) data sets. About 35% of these taxa appeared or became largely distributed later than 1970. Significant changes in frequency during the study period were observed for 53 taxa. The period of rapid eutrophication since the 1970s coincided with a clear increase in the species number in the southern, recently hypertrophic lake part. Changes in Shannon’s diversity index were analogous to the dynamics of species number, but species evenness did not change significantly. Species that appeared and/or increased their frequency after the 1970s were common hygrophytes, helophytes, and amphibious plants inhabiting the overgrowing littoral. A remarkable growth was observed in the frequency of Phalaris arundinacea, Glyceria maxima, Sium latifolium, Agrostis stolonifera, and Rorippa amphibia while among hydrophytes mainly plants of sheltered habitats such as Spirodela, Hydrocharis, Lemna, Nuphar, Ceratophyllum, Sparganium, Stratiotes, and Elodea increased their frequency. In repeatedly studied 22 stations filamentous algae, Potamogeton gramineus, P. pectinatus, and Stratiotes had appeared by 1980. In these 22 stations the average species number per year in 1997–2014 was similar to or lower than in 1980, and the total average had decreased. Using cluster analyses of 243 observations in 52 stations, six contemporary characteristic littoral vegetation types for L. Peipsi were identified, among them species-rich small landing places and wide monodominant reeds. Our results indicate that anthropogenic eutrophication increased the species number of macrophytes at its beginning, but in L. Peipsi the hump-backed curve is not clearly expressed. The number of species in the lake stays stable due to large oscillations in the water level, removal of reeds, and cleaning of boat canals.
Adler, P. B., Seabloom, E. W., Borer, E. T., Hillebrand, H., Hautier, Y., Hector, A., et al. 2011. Productivity is a poor predictor of plant species richness. Science, 333, 1750–1753.
https:/doi.org/10.1126/science.1204498
Alahuhta, J., Kanninen, A. & Vuori, K.-M. 2012. Response of macrophyte communities and status metrics to natural gradients and land use in boreal lakes. Aquat. Bot., 103, 106–114.
https:/doi.org/10.1016/j.aquabot.2012.07.003
Alahuhta, J., Kanninen, A., Hellsten, S., Vuori, K.-M., Kuoppala, M., and Hämäläinen, H. 2014. Variable response of functional macrophyte groups to lake characteristics, land use, and space: implications for bioassessment. Hydrobiologia, 737, 201–214.
https:/doi.org/10.1007/s10750-013-1722-3
Andersson, B. 2001. Macrophyte development and habitat characteristics in Sweden’s large akes. AMBIO, 30(8), 503–513.
https:/doi.org/10.1579/0044-7447-30.8.503
Berendse, F. and Aerts, R. 1994. Nitrogen-use efficiency: A biologically meaningful definition? Funct. Ecol., 1, 293–296.
De Cáceres, M., Legendre, P., and Moretti, M. 2010. Improving indicator species analysis by combining groups of sites. Oikos, 119(10), 1674–1684.
https:/doi.org/10.1111/j.1600-0706.2010.18334.x
Dodds, W. K. and Gudder, D. A. 1992. The ecology of Cladophora. J. Phycol., 28, 415–427.
https:/doi.org/10.1111/j.0022-3646.1992.00415.x
Foster, B. L. and Gross, K. L. 1998. Species richness in a successional grassland: effects of nitrogen enrichment and plant litter. Ecology, 71, 2593–2602.
https:/doi.org/10.1890/0012-9658(1998)079[2593:SRIASG]2.0.CO;2
Fraser, L. H., Pither, J., Jentsch, A., Sternberg, M., Zobel, M., Askarizadeh, D., et al. 2015. Worldwide evidence of a unimodal relationship between plant productivity and species richness. Science, 349, 302–305.
https:/doi.org/10.1126/science.aab3916
Freund, J. F. and Wilson, W. J. 2003. Statistical Methods. Academic Press, USA.
Graham, J. H. and Duda, J. J. 2011. The humpbacked species richness-curve: a contingent rule for community ecology. Int. J. Ecol., 2011, article ID 868426.
https:/doi.org/10.1155/2011/868426
Grime, J. P. 2007. Plant strategy theories: a comment on Craine (2005). J. Ecol., 95, 227–230.
https:/doi.org/10.1111/j.1365-2745.2006.01163.x
Haldna, M., Möls, T., Buhvestova, O., and Kangur, K. 2013. Predictive model for phosphorus in the large shallow Lake Peipsi: approach based on covariance structures. Aquat. Ecosyst. Health Manag., 16(2), 222−226.
Hillebrand, H., Gruner, D. S., Borer, E. T., Bracken, M. E., Cleland, E. E., Elser, J. J., et al. 2007. Consumer versus resource control of producer diversity depends on ecosystem type and producer community structure. Proc. Natl. Acad. Sci. USA, 104,10904–10909.
https:/doi.org/10.1073/pnas.0701918104
Hothorn, T. and Everitt, B. S. 2014. A Handbook of Statistical Analyses Using R. Third Edition. CRC Press, Boca Raton, FL.
Jaani, A., Klaus, L., Pärn, O., Raudsepp, U., Zadonskaja, O., Gronskaja, T., and Solntsev, V. 2008. Ηüdroloogia [Hydrology]. In Peipsi (Timm, T., Raukas, A., and Haberman, J., eds), pp. 113–155. Eesti Loodusfoto, Tartu (in Estonian).
Jenkins, M. 2003. Prospects for biodiversity. Science, 302, 1175–1177.
https:/doi.org/10.1126/science.1088666
Jupp, B. P. and Spence, D. H. N. 1977. Limitations on macrophytes in a eutrophic lake, Loch Leven: I. Effects of phytoplankton. J. Ecol., 65, 175–186.
https:/doi.org/10.2307/2259493
https:/doi.org/10.2307/2259072
Kangur, K. and Möls, T. 2008. Changes in spatial distribution of phosphorus and nitrogen in the large north-temperate lowland Lake Peipsi (Estonia/Russia). Hydrobiologia, 599, 31–39.
https:/doi.org/10.1007/s10750-007-9204-0
Kangur, K., Milius, A., Möls, T., Laugaste, R., and Haberman, J. 2002. Lake Peipsi: changes in nutrient elements and plankton communities in the last decade. Aquat. Ecosyst. Health Manag., 5(3), 363–377
https:/doi.org/10.1080/14634980290001913
Kangur, M., Kangur, K., Laugaste, R., Punning, J.-M., and Möls, T. 2007. Combining limnological and palaeolimnological approaches in assessing degradation of Lake Pskov. Hydrobiologia, 584, 121–132.
https:/doi.org/10.1007/s10750-007-0597-6
Kangur, K., Kangur, P., Ginter, K., Orru, K., Haldna, M., Möls, T., and Kangur, A. 2013. Long-term effects of extreme weather events and eutrophication on the fish community of shallow lake Peipsi (Estonia/Russia). J. Limnol., 72(2), 376–387.
https:/doi.org/10.4081/jlimnol.2013.e30
Katanskaya, V. M. 1981. Vysshaya vodnaya rastitel´nost´ kontinental´nykh vodoemov SSSR. Leningrad.
Kolada, A., Hellsten, S., Søndergaard, M., Mjelde, M., Dudley, B., van Geest, G., et al. 2011. Report of the most suitable lake macrophyte based assesment methods for impacts of eutrophication and water level fluctuations. Deliverable D3.2-3 of the Wiser project.
Keddy, P. A. 2010. Wetland Ecology. Principles and Conservation. Second edition. Cambridge University Press.
https:/doi.org/10.1017/CBO9780511778179
Leeben, A., Freiber, R., Tõnno, I., Kõiv, T., Alliksaar, T., and Heinsalu, A. 2013. A comparison of the palaeolimnology of Peipsi and Võrtsjärv: connected shallow lakes in north-eastern Europe for the twentieth century, especially in relation to eutrophication progression and water-level fluctuations. Hydrobiologia, 710, 227–240.
https:/doi.org/10.1007/s10750-012-1209-7
Mäemets, H. and Freiberg, L. 2004. Characteristics of reeds on Lake Peipsi and the floristic consequences of their expansion. Limnologica, 34, 83–89.
https:/doi.org/10.1016/S0075-9511(04)80025-2
Mäemets, H. and Mäemets, A. 2000. Commented list of macrophyte taxa of Lake Peipsi. Proc. Estonian Acad. Sci. Biol. Ecol., 49, 136–154.
Mäemets, H. and Mäemets, A. 2001. Macrophytes. In Lake Peipsi. III. Flora and Fauna (Haberman, J. and Pihu, E., eds), pp. 9–22. Sulemees Publishers, Tartu.
Mäemets, A., Timm, M., and Nõges, T. 1996. Zooplankton of Lake Peipsi-Pihkva in 1909–1987. Hydrobiologia, 338, 105–112.
https:/doi.org/10.1007/BF00031714
Mäemets, H., Palmik, K., Haldna, M., Sudnitsyna, D., and Melnik, M. 2010. Eutrophication and macrophyte species richness in the large shallow North-European Lake Peipsi. Aquat. Bot., 92, 273–280.
https:/doi.org/10.1016/j.aquabot.2010.01.008
Michelan, T. S., Thomaz, S. M., Mormul, R. P., and Carvalho, P. 2010. Effects of an exotic invasive macrophyte (tropical signalgrass) on native plant community composition, species richness and functional diversity. Freshwater Biol., 55, 1315–1326.
https:/doi.org/10.1111/j.1365-2427.2009.02355.x
Milius, A. and Haldna, M. 2008. Hüdrokeemia [Hydrochemistry]. In Peipsi (Haberman, J., Timm, T., and Raukas, A., eds), pp. 157–178. Eesti Loodusfoto, Tartu (in Estonian).
Nedospasova, G. V. 1974. Vysshaya vodnaya rastitel´nost´ Pskovsko-Csudskogo vodoema [Higher water vegetation of Lake Pskov-Peipsi]. Izvestiya GosNIORKh, 83, 26–32 (in Russian).
Oksanen, J., Blanchet, F. G., Kindt, R., Legendre, P., Minchin, P. R., O'Hara, R. B., et al. 2012. vegan: Community Ecology Package. R package version 2.0-2. 2011.
Palmik, K., Mäemets, H., Haldna, M., and Kangur, K. 2013. A comparative study of macrophyte species richness in differently managed shore stretches of Lake Peipsi. Limnologica, 43, 245–253.
https:/doi.org/10.1111/j.1365-2427.2009.02355.x
Penning, W. E., Dudley, B., Mjelde, M., Hellsten, S., Hanganu, J., Kolada, A., et al. 2008. Using aquatic macrophyte community indices to define the ecological status of European lakes. Aquat. Ecol., 42, 253–264.
https:/doi.org/10.1007/s10452-008-9183-x
Rajaniemi, T. K. 2003. Explaining productivity–diversity relationships in plants. Oikos, 101, 449–457.
https:/doi.org/10.1034/j.1600-0706.2003.12128.x
Raukas, A. 2008. Peipsi nõo pinnakatte koostisest ja setete vanusest [On the composition of the Quaternary cover and age of deposits in the depression of Lake Peipsi]. In Peipsi (Timm, T., Raukas, A., and Haberman, J., eds), pp. 33–41. Loodusfoto, Tartu (in Estonian).
R Core Team. 2013. R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org/ (accessed 2016-09-26).
Sala, O. E., Chapin III, F. S., Armesto, J. J., Berlow, E., Bloomfield, J., Dirzo, R., et al. 2000. Global biodiversity scenarios for the year 2100. Science’s Compass, 287, 1770–1774.
https:/doi.org/10.1126/science.287.5459.1770
Sand-Jensen, K., Lagergaard Pedersen, N., Thorsgaard, I., Moeslund, B., Borum, J., and Brodersen, K. P. 2008. 100 years of vegetation decline and recovery in Lake Fure, Denmark. J. Ecol., 96, 260–271.
https:/doi.org/10.1111/j.1365-2745.2007.01339.x
Starast, H., Milius, A., Möls, T., and Lindpere, A. 2001. Hydrochemistry of Lake Peipsi. In Lake Peipsi. Meteorology. Hydrology. Hydrochemistry (Nõges, T. ed.), pp. 97–131. Sulemees Publishers, Tartu.
Sudnitsyna, D. N., Mel´nik, M. M., and Mäemets, H. 2008. Flora Pskovsko-Chudskogo ozera [Flora of Lake Peipsi]. Vestnik Pskovskogo Gosudarstvennogo Pedagogicheskogo Universiteta, 6, 23–57 (in Russian).
Tammeorg, O., Niemistö, J., Möls, T., Laugaste, R., Panksep, K., and Kangur, K. 2013. Wind-induced sediment resuspension as a potential factor sustaining eutrophication in large and shallow Lake Peipsi. Aquat. Sci., 75, 559–570.
https:/doi.org/10.1007/s00027-013-0300-0
Tuvikene, H. 1966. O vysshej vodnoi rastitel´nosti Chudsko-Pskovskogo ozera [Macrophyte vegetation of Lake Peipsi-Pihkva]. Hydrobiological Researches 4, 75–79. Tallinn (in Russian).
USDA-NRCS. 2009. The PLANTS Database. Baton Rouge, USA: National Plant Data Center. http:// plants.usda.gov/ (accessed 2016-05-09).
Vaher, R. 2008. Tektoonika [Tectonics]. In Peipsi (Timm, T., Raukas, A., Haberman, J., eds), pp. 21–24. Loodusfoto, Tartu (in Estonian).
Van Geest, G. J., Coops, H., Roijackers, M. M., Buijse, A. D., and Scheffer, M. 2005a. Succession of aquatic vegetation driven by reduced water-level fluctuations in floodplain lakes. J. Appl. Ecol., 42, 251–260.
https:/doi.org/10.1111/j.1365-2664.2005.00995.x
Van Geest, G. J., Wolters, H., Roozen, F. C. J. M., Coops, H., Roijackers, R. M. M., Buijse, A. D., and Scheffer, M. 2005b. Water-level fluctuations affect macrophyte richness in floodplain lakes. Hydrobiologia, 539, 239–248.
https:/doi.org/10.1007/s10750-004-4879-y
Van Geest, G. J., Coops, H., Scheffer, M., and Van Nes, E. H. 2007. Long transients near the ghost of a stable state in eutrophic shallow lakes with fluctuating water levels. Ecosystems, 10, 36–46.
https:/doi.org/10.1007/s10021-006-9000-0
Ward, J. H. 1963. Hierarchical grouping to optimize an objective function. JASA, 58, 236–244.
https:/doi.org/10.1080/01621459.1963.10500845
Wei, A. and Chow-Fraser, P. 2006. Synergistic impact of water level fluctuation and invasion of Glyceria on Typha in a freshwater marsh of Lake Ontario. Aquat. Bot., 84, 63–69.
https:/doi.org/10.1016/j.aquabot.2005.07.012
https:/doi.org/10.2307/3236106
