Environmental Changes in a High Arctic Ecosystem

Eveline Pinseel
Persbericht

Environmental Changes in a High Arctic Ecosystem

Hoe kiezelalgen geschiedenis schrijven

We bevinden ons in een tijd van snelle en ingrijpende milieuveranderingen als gevolg van de door de onszelf veroorzaakte klimaatsverandering. Maar hoe kunnen we de huidige impact van de klimaatsopwarming inschatten? Hoe kunnen we weten in welke mate onze omgeving al veranderd is? Waar metereologische waarnemingen niet beschikbaar zijn, kunnen kiezelalgen een tipje van de sluier oplichten!

Kiezelalgen of diatomeeën zijn eencellige algen die gekenmerkt worden door een geelbruine pigmentatie en celwanden (schaaltjes) opgebouwd uit kiezel (siliciumdioxide). Deze celwand bestaat uit twee helftjes, de valven, die in elkaar passen als een smeerkaasdoosje en waarbinnen de cel huist. Diatomeeën vormen de meest soortenrijke groep van algen op aarde. Men vermoedt dat er tussen de 20 000 en 200 000 verschillende soorten bestaan. Hun gigantische diversiteit en hun prachtige morfologie sprak reeds vele wetenschappers tot de verbeelding. Daarnaast zijn diatomeeën zeer wijdverspreid in zowel terrestrische als aquatische habitats. Hoewel ze niet met het blote oog waarneembaar zijn, behoren ze tot de belangrijkste zuurstofproducenten op aarde. Diatomeeën zijn werkelijk onze longen, maar daarnaast kunnen ze ons ook een unieke inkijk geven op het verleden van onze planeet.

Hoe algen het verleden kunnen ontrafelen

Diatomeeën hebben zeer specifieke ecologische voorkeuren en zullen bijgevolg enkel in een omgeving voorkomen die ook geschikt is voor hen. Daarnaast bewaren hun schaaltjes uitzonderlijk goed in meersedimenten en kunnen ze duizenden jaren later nog teruggevonden en geïdentificeerd worden. Door een boorkern te nemen uit de sedimenten van een meer en de hierin aanwezige diatomeeënschaaltjes te isoleren, kan een tijdssequentie bekomen worden van de diatomeeënpopulaties die in het meer voorkwamen. De omgevingsvoorkeuren van de dominerende soorten in deze boorkern kunnen op die manier gebruikt worden om een reconstructie van de omgeving en het klimaat uit het verleden te maken. Door naar de veranderingen in de dominerende soorten te kijken, kunnen zo belangrijke omgevingsveranderingen in kaart gebracht worden. De wetenschap die dit beoefent is de paleoecologie.

Paleoecologisch onderzoek is vooral interessant in polaire gebieden. Er bestaan immers geen lange termijn klimatologische waarnemingen voor deze regio’s en bovendien zijn ze zeer gevoelig voor klimaatsveranderingen. Echter, het gebruik van diatomeeën in paleoecologie in de poolgebieden wordt bemoeilijkt door onze beperkte kennis van de diversiteit en ecologie van diatomeeën in deze gebieden. Dat is voornamelijk een gevolg van het te beperkt aantal studies dat hier werd uitgevoerd. Daarnaast zijn veel diatomeeën in het noordpoolgebied in het verleden foutief geïdentificeerd. Om onze kennis over de diatomeeëndiversiteit en –ecologie in het noordpoolgebied te verbeteren en zo hun toepassing in de paleoecologie te bevorderen, werden in deze studie de zoetwaterdiatomeeëngemeenschappen in Petuniabukta, een fjord gebied in Spitsbergen (Svalbard Archipel, Arctisch gebied), onderzocht op een ruimtelijke en een temporele schaal.

Diatomeeën & hun omgeving

Tijdens de poolzomer van 2013 werden stalen voor diatomeeën genomen uit 40 meren en poelen in Petuniabukta. De aanwezige diatomeeënflora werd geanalyseerd met behulp van licht- en rasterelektronenmicroscopie. In totaal werden 315 verschillende taxa (d.i. een soort, ondersoort of variëteit) teruggevonden. Vervolgens liet statistische analyse toe om de gevonden diatomeeënflora op te delen in vier verschillende diatomeeëngemeenschappen. Deze gemeenschappen komen voor in meren die duidelijk verschillen in omgevingscondities, zoals de aanwezigheid van stroming, vogelkolonies, mosbegroeiing aan de meerranden, invloeden van gletsjers en spatwater van de zee. Op deze manier geven ze een indicatie van de ecologische voorkeuren van de samenstellende soorten en die kunnen dan weer gebruikt worden in paleoecologisch onderzoek.

Nieuw voor de wetenschap

Verschillende van de diatomeeën die werden teruggevonden in de meerstalen bleken tot nu toe onbekend voor de wetenschap. Dit leidde reeds tot de beschrijving van een nieuwe soort, Gomphonema svalbardense Pinseel, Kopalová & Van de Vijver (zie figuur), en het is duidelijk dat in de toekomst meer nieuwe soorten beschreven zullen worden uit deze studie. Dit toont aan dat de diatomeeëndiversiteit van het Arctisch gebied niet goed gekend is en dat nog veel soorten ontdekt en beschreven moeten worden. Er is dus nog voor jaren werk voor enthousiaste algologen!

6000 jaar terug in de tijd

In het tweede deel van deze studie werd getracht de omgevingsveranderingen van de laatste millennia in Petuniabukta te reconstrueren door gebruik te maken van diatomeeën. Hiervoor werd een boorkern genomen uit de meersedimenten van een meer in het studiegebied. Door middel van koolstof-14-datering, een radiometrische dateringsmethode, werd de ouderdom van de 79 cm lange boorkern bepaald op ~ 6000 jaar. Vervolgens werden de veranderingen in de diatomeeënsamenstelling doorheen de sedimentkern onderzocht. De resultaten gaven aan dat de diatomeeëngemeenschappen van Garmaksla een aantal grote wijzigingen hebben ondergaan in de afgelopen 6000 jaar. De ecologische voorkeuren van de samenstellende taxa suggereren opeenvolgende periodes van opwarming en afkoeling in de afgelopen millennia. Echter, de meest dramatische wijziging trad op in de opperste 11 cm van de sedimentkern waar een verschuiving plaatsvond naar een diatomeeëngemeenschap die een duidelijke voorkeur heeft voor een warmer klimaat met minder lange periodes van ijsbedekking. Hoogstwaarschijnlijk kan deze verandering worden toegeschreven aan de invloeden van de recente klimaatsveranderingen in het Arctisch gebied, in het bijzonder het door natuurlijke omstandigheden veroorzaakte einde van de Kleine IJstijd, zo’n 100 tot 150 jaar geleden, en, meer recent, de door de mens geïnduceerde klimaatsopwarming, wat geleid heeft tot luchttemperaturen die hoger zijn dan wat in de afgelopen eeuwen of zelfs millennia de regel was voor het Arctisch gebied.

‘Take home message’

Naast een unieke inkijk op het klimaat uit het verleden, tonen de resultaten van deze studie aan dat de diatomeeëngemeenschappen in de Arctis recent grote veranderingen hebben ondergaan en dat ze zich momenteel verwijderen van hun ecologisch evenwicht van de afgelopen eeuwen tot zelfs millennia. Indien de klimaatsopwarming doorzet, bestaat het risico dat we de typische Arctische diatomeeëngemeenschappen zullen verliezen.

Bibliografie

1.                    Adl SM, Simpson AG, Lane CE, Lukes J, Bass D, Bowser SS, Brown MW, Burki F, Dunthorn M, Hampl V, Heiss A, Hoppenrath M, Lara E, Le Gall L, Lynn DH, McManus H, Mitchell EA, Mozley-Stanridge SE, Parfrey LW, Pawlowski J, Rueckert S, Shadwick RS, Schoch CL, Smirnov A, & Spiegel FW (2012) The revised classification of eukaryotes. The Journal of eukaryotic microbiology 59(5):429-493.

2.                    Antoniades D & Douglas MSV (2002) Characterization of high arctic stream diatom assemblages from Cornwallis Island, Nunavut, Canada. Canadian Journal of Botany 80(1):50-58.

3.                    Antoniades D, Douglas MSV, & Smol JP (2005) Quantitative estimates of recent environmental changes in the Canadian High Arctic inferred from diatoms in lake and pond sediments. Journal of Paleolimnology 33:349-360.

4.                    Antoniades D, Hamilton PB, Douglas MSV, & Smol JP (2008) Diatoms of North America: the freshwater flora of Prince Patrick, Ellef Ringnes and northern Ellesmere Islands from the Canadian Arctic Archipelago. Iconographia Diatomologica, ed Lange-Bertalot H (Koeltz Scientific Books, Koenigstein), Vol 17, p 649.

5.                    Antoniades D, Hamilton PB, Hinz F, Douglas MSV, & Smol JP (2009) Seven new species of freshwater diatoms (Bacillariophyceae) from the Canadian Arctic Archipelago. Nova Hedwigia 24:57-80.

6.                    Baas-Becking LGM (1934) Geobiologie of inleiding tot de milieukunde (Van Stockum and Zoon, The Hague).

7.                    Baeten NJ, Forwick M, Vogt C, & Vorren TO (2010) Late Weichselian and Holocene sedimentary environments and glacial activity in Billefjorden, Svalbard. Geological Society, London, Special Publications 344(1):207-223.

8.                    Battarbee RW (2000) Paleolimnological approaches to climate change, with special regard to the biological record. Quaternary Science Reviews 19:107-124.

9.                    Battarbee RW, Jones VJ, Flower RJ, Cameron NG, Bennion H, Carvalho L, & Juggins S (2001) Diatoms Tracking Environmental Change Using Lake  Sediments. Volume 3: Terrestrial, Algal, and Siliceous Indicators, eds Smol JP, Birks HJB, & Last WM (Kluwer Academic Publishers, Dordrecht, The Netherlands), pp 155-202.

10.                 Bennett KD (1996) Determination of the number of zones in a biostratigraphical sequence. New Phytologist 132:155-170.

11.                 Betts-Piper AM, Zeeb BA, & Smol JP (2004) Distribution and autecology of chrysophyte cysts from high Arctic Svalbard lakes: preliminary evidence of recent environmental change. Journal of Paleolimnology 31:467-481.

12.                 Beyens L & De Bock P (1989) Moss Dwelling Diatom Assemblages from Edgeøya (Svalbard). Polar Biology 9:423-430.

13.                 Beyens L & Denys L (1982) Problems in diatom analysis of deposits: Allochtonous valves and fragmentation. Geologie en Mijnbouw 61:159-162.

14.                 Beyens L & Van de Vijver B (2000) First contribution to the diatom flora of High Arctic Hopen Island (Svalbard). Nova Hedwigia 70:409-424.

15.                 Birks HH (1991) Holocene vegetational history and climatic change in west Spitsbergen - plant macrofossils from Skardtjørna, an Arctic Lake. The Holocene 1:209-215.

16.                 Birks HH, Paus A, Svendsen JI, Alm T, Mangerud J, & Landvik JY (1994) Late Weichselian environmental change in Norway, including Svalbard. Journal of Quaternary Science 9(2):133-145.

17.                 Birks HJB, Jones VJ, & Rose NL (2004) Recent environmental change and atmospheric contamination on Svalbard as recorded in lake sediments - an introduction. Journal of Paleolimnology 31:403-410.

18.                 Birks HJB, Jones VJ, & Rose NL (2004) Recent environmental change and atmospheric contamination on Svalbard as recorded in lake sediments - synthesis and general conclusions. Journal of Paleolimnology 31:531-546.

19.                 Birks HJB, Monteith DT, Rose NL, Jones VJ, & Peglar SM (2004) Recent environmental change and atmospheric contamination on Svalbard as recorded in lake sediments - modern limnology, vegetation, and pollen deposition. Journal of Paleolimnology 31:411-431.

20.                 Bradshaw EG, Jones VJ, Birks HJB, & Birks HH (2000) Diatom responses to late-glacial and early-Holocene environmental changes at Kråkenes, western Norway. Journal of Paleolimnology 23:21-34.

21.                 Bukhtiyarova L & Round FE (1996) Revision of the genus Achnanthes sensu lato. Psammothidium, a new genus based on A. marginulatum. Diatom Research 11(1):1-30.

22.                 Chao A (1984) Non-parametric estimation of the number of classes in a population. Scandinavian Journal of statistics 11:265-270.

23.                 Chao A, Hwang WH, Chen YC, & Kyo CY (2000) Estimating the number of shared species in two communities. Statistica sinica 10:227-246.

24.                 Chipman ML, Clarke GH, Clegg BF, Gregory-Eaves I, & Hu FS (2008) A 2000 year record of climatic change at Ongoke Lake, southwest Alaska. in Journal of Paleolimnology, pp 57-75.

25.                 Clark PU, Dyke AS, Shakun JD, Carlson AE, Clark J, Wohlfarth B, Mitrovica JX, Hostetler SW, & McCabe AM (2009) The Last Glacial Maximum. Science 325(5941):710-714.

26.                 Cleve PT (1867) Diatomaceer från Spetsbergen. Översight af Kongl. Vetenskaps-Akademiens Forhandlinger 24:661-669.

27.                 Cleve PT (1898) Diatoms from Franz Josef Land. Bihang Till Kongliga Svenska Vetenskaps-Akademiens Handlingar 24:1-26.

28.                 Cody ML (1975) Ecology and evolution of communities. Towards a theory of continental species diversity bird distributions over Mediterranean habitat gradients, eds Cody ML & Diamond JM (Harvard University Press, Cambridge, Mass), pp 214-257.

29.                 Colwell RK (2013) EstimateS: statistical estimation of species richness and shared species from samples. Version 9. User's Guide and application published at http://viceroy.eeb.uconn.edu/estimates/.

30.                 Cremer H (2006) The planktonic diatom flora of a High Arctic lake in East Greenland. Nordic Journal of Botany 24:235-244.

31.                 Cremer H, Bennike O, & Hakansson L (2005) Hydrology and diatom phytoplankton of High Arctic lakes and ponds on Store Koldewey, northeast Greenland. International Review of Hydrobiology 90:84-89.

32.                 Cremer H, Wagner B, Melles M, & Hubberten H-W (2001) The postglacial environmental development of Raffles Sø, East Greenland: inferences from a 10,000 year diatom record. Journal of Paleolimnology 26:67-87.

33.                 Cumming BF & Smol JP (1993) Paleolimnological potential of chrysophyte cysts and scales and of sponge spicules as indicators of lake salinity. International Journal of Salt Lake Research 2:87-92.

34.                 D'Andrea WJ, Vaillencourt DA, Balascio NL, Werner A, Roof SR, Retelle M, & Bradley RS (2012) Mild Little Ice Age and unprecedented recent warmth in an 1800 year lake sediment record from Svalbard. Geology 40(11):1007-1010.

35.                 Dallmann WK, Dypvik H, Gjelberg JG, Harland WB, Johannessen EP, Keilen HB, Larssen GB, Lønøy A, Midbøe PS, Mørk A, Nagy J, Nilsson I, Nøttvedt A, Olaussen S, Pèelina TM, Steel RJ, & Worsley D (1999) Lithostratigraphic Lexicon of Svalbard (Norsk Polarinstitutt, Oslo) p 318.

36.                 De Queiroz K (2007) Species concepts and species delimitation. Systematic biology 56(6):879-886.

37.                 Denys L (1988) Fragilaria Blooms in the Holocene of the Western Coastal Plain of Belgia. Proceedings of the tenth international diatom symposium:397-406.

38.                 Denys L (1991) A check-list of the diatoms in the Holocene deposits of the western Belgian coastal plain with a survey of their apparent ecological requirements. I. Introduction, ecological code and complete list. Ministère des Affaires Economiques - Sérvice Geologique de Belgique.

39.                 Denys L & Beyens L (1987) Some diatom assemblages from the Angmagssalik region, south-east Greenland. Nova Hedwigia 45:389-413.

40.                 Douglas MSV & Smol JP (1993) Freshwater diatoms from high arctic ponds (Cape Herschel, Ellesmere Island, N. W. T.). Nova Hedwigia 57(3-4):511-552.

41.                 Douglas MSV & Smol JP (1995) Periphytic diatom assemblages from high arctic ponds. Journal of Phycology 31:60-69.

42.                 Douglas MSV & Smol JP (2010) Freshwater diatoms as indicators of environmental change in the High Arctic. The Diatoms: Applications for the Environmental and Earth Sciences, eds Smol JP & Stoermer EF (Cambridge University Press, New York), pp 249-266.

43.                 Douglas MSV, Smol JP, & Blake WJ (1994) Marked Post-18th Century Environmental Change in High-Arctic Ecosystems. Science 266:416-419.

44.                 Edward H & Cappelen J (2003) Recent cooling in coastal southern Greenland and relation with the North Atlantic Oscillation. Geophysical Research Letters 30(3):DOI: 10.1029/2002GL015797.

45.                 Elverhøi A, Svendsen JI, Solheim A, Andersen ES, Milliman J, Mangerud J, & Hooke RL (1995) Late Quaternary sediment yield from the High Arctic Svalbard area. Journal of Geology 103:1-17.

46.                 Fenchel T & Finlay BJ (2004) The Ubiquity of Small Species: Patterns of Local and Global Diversity. Bioscience 54:777-784.

47.                 Finkelstein SA & Gajewski K (2007) A palaeolimnological record of diatom-community dynamics and late-Holocene climatic changes from Prescott Island, Nunavut, central Canadian Arctic. The Holocene 17(6):803-812.

48.                 Finkelstein SA & Gajewski K (2008) Responses of Fragilarioid-dominated diatom assemblages in a small Arctic lake to Holocene climatic changes, Russell Island, Nunavut, Canada. Journal of Paleolimnology.

49.                 Finlay BJ (2002) Global dispersal of free-living microbial eukaryote species. Science 296(5570):1061-1063.

50.                 Foged N (1953) Diatoms from West Greenland. Meddelelser om Grönland 147:1-86.

51.                 Foged N (1955) Diatoms from Peary Land, North Greenland. Meddelelser om Grönland 194:1-66.

52.                 Foged N (1958) The diatoms in the basalt area and adjoining areas of Archean rock in West Greenland. Meddelelser om Grönland 156:1-146.

53.                 Foged N (1964) Freshwater diatoms from Spitsbergen. Tromsö Museums Skrifter 11:1-204.

54.                 Foged N (1972) The diatoms in four postglacial deposits in Greenland. Meddelelser om Grönland 194:1-66.

55.                 Foged N (1973) Diatoms from Southwest Greenland. Meddelelser om Grönland 194:1-84.

56.                 Foged N (1974) Freshwater diatoms in Iceland. Bibliotheca Phycologia,  (J. Cramer, Vaduz), Vol 15, p 118.

57.                 Foged N (1977) Diatoms from four postglacial deposits at Godthabsfjord West Greenland. Meddelelser om Grönland 199:1-64.

58.                 Foged N (1981) Diatoms in Alaska. Bibliotheca Phycologica,  (J. Cramer, Vaduz), Vol 53, p 317.

59.                 Foged N (1982) Diatoms in human tissues - Greenland ab. 1460 AD - Funen 1981-82 AD. Nova Hedwigia 36:345-379.

60.                 Foged N (1989) The subfossil diatom flora of four geographically widely separated cores in Greenland. Meddelelser om Grönland (Bioscience) 30:1-75.

61.                 Førland EJ & Hanssen-Bauer I (2003) Past and future climate variations in the Norwegian Arctic: overview and novel analyses. Polar Research 22(2):113-124.

62.                 Forman SL, Lubinski DJ, Ingólfsson Ó, Zeeberg JJ, Snyder JA, Siegert MJ, & Mathishov GG (2004) A review of postglacial emergence on Svalbard, Franz Josef Land and Novaya Zemlya, northern Eurasia. Quaternary Science Reviews 23:1391-1434.

63.                 Fourtanier E & Kociolek JP (2011) Catalogue of Diatom Names, California Academy of Sciences, Online Version updated 19 Sept. 2011. – Available online at http://researcharchive.calacademy.org/research/diatoms/names/.

64.                 Fritz SC, Cumming BF, Gasse F, & Laird KR (2010) Diatoms as indicators of hydrologic and climate change in saline lakes. The Diatoms: Applications for the Environmental and Earth Sciences, eds Smol JP & Stoermer EF (Cambridge University Press, New York, USA), 2 Ed, pp 186-208.

65.                 Gibas J, Rachlewicz G, & Szczuciński W (2005) Application of DC resistivity soundings and geomorphological surveys in studies of modern Arctic glacier marginal zones, Petuniabukta, Spitsbergen. Polish Polar Research 26(4):239-258.

66.                 Gordiyenko FG, Kotlyakov VM, Punning Y-KM, & Vairmäe R (1980) Study of a 200-m core from the Lomonosov Ice Plateau on Spitsbergen and the paleoclimatic implications. Polar Geography and Geology 5(4):242-251.

67.                 Grimm EC (1987) CONISS, a FORTRAN-77 program for stratigraphically constrained cluster analysis by the method of incremental sum of squares. Computers & Geosciences 13:13-15.

68.                 Grimm EC (1991) Tilia version 2.0b4 (Springfield, Illinois State Museum, Illinois).

69.                 Grinsted A, Moore JC, Pohjola V, Martma T, & Isaksson E (2006) Svalbard summer melting, continentality, and sea ice extent from the Lomonosovfonna ice core. Journal of Geophysical Research 111:D7.

70.                 Guilizzoni P, Marchetto A, Lami A, Brauer A, Vigliotti L, Musazzi S, Langone L, Manca M, Lucchini F, Calanchi N, Dinelli E, & Mordenti A (2006) Records of environmental and climatic changes during the late Holocene from Svalbard: palaeolimnology of Kongressvatnet. Journal of Paleolimnology 36(4):325-351.

71.                 Guiry MD (2012) How Many Species of Algae Are There? Journal of Phycology 48(5):1057-1063.

72.                 Hanssen-Bauer I & Førland EJ (1998) Long-term trends in precipitation and temperature in the Norwegian Arctic: can they be explained by changes in atmospheric circulation patterns? Climate Research 10:143-153.

73.                 Harland WB, Cutbill JL, P.F. F, Gobbett DJ, Holliday DW, Marton PI, Parker JR, & Wallis H (1974) The Billefjorden Fault Zone, Spitsbergen. The long history of a major tectonic lineament. (Norsk Polarinstitutt Skirfter, Oslo) p 72.

74.                 Haworth EY (1976) Two late-glacial (late Devensian) diatom assemblage profiles from nother Scotland. New Phytologist 77:227-256.

75.                 Hein MK (1990) Flora of Adak Island, Alaska: Bacillariophyceae (Diatoms). Bibliotheca Diatomologica, ed Lange-Bertalot H (J. Cramer, Berlin/Stuttgart), Vol 21, p 133.

76.                 Hickman M (1974) The epipelic diatom flora of a small lake on Baffin Island, Northwest Territories. Archiv für Protistenk 116(3):270-279.

77.                 Hodgson DA & Smol JP (2008) High-latitude paleolimnology. Polar Lakes and Rivers. Limnology of Arctic and Antarctic Aquatic Ecosystems., eds Vincent WF & Laybourn-Parry J (Oxford University Press, New York), pp 43-64.

78.                 Hofmann G, Werum M, & Lange-Bertalot H (2011) Diatomeen im Süßwasserflora-Benthos von Mitteleuropa (A. R. G. Gantner Verlag K. G., Rugell) p 908.

79.                 Holmgren SU, Bigler C, Ingólfsson Ó, & Wolfe AP (2010) The Holocene–Anthropocene transition in lakes of western Spitsbergen, Svalbard (Norwegian High Arctic): climate change and nitrogen deposition. Journal of Paleolimnology 43(2):393-412.

80.                 Humlum O, Instanes A, & Sollid JL (2003) Permafrost in Svalbard: a review of research history, climatic background and engineering challenges. Polar Research 22(2):191-215.

81.                 Hustedt F (1937) Süsswasserdiatomen von Island, Spitsbergen und den Färöer-Inseln. Bot. Arch. 38:152-207.

82.                 Ingólfsson Ó & Landvik JY (2013) The Svalbard–Barents Sea ice-sheet – Historical, current and future perspectives. Quaternary Science Reviews 64:33-60.

83.                 Isaksson E, Hermanson M, Hicks S, Igarashi M, Kamiyama K, Moore J, Motoyama H, Muir D, Pohjola V, Vairmäe R, van de Wal RSW, & Watanabe O (2003) Ice cores from Svalbard––useful archives of past climate and pollution history. Physics and Chemistry of the Earth, Parts A/B/C 28(28-32):1217-1228.

84.                 Isaksson E, Kohler J, Pohjola V, Moore J, Igarashi M, Karlöf L, Martma T, Meijer H, Motoyama H, Vaikmäe R, & van de Wal RSW (2005) Two ice-core δ18O records from Svalbard illustrating climate and sea-ice variability over the last 400 years. The Holocene 15(501-509).

85.                 Jiang S, Liu X, Sun J, Yuan L, Sun L, & Wang Y (2011) A multi-proxy sediment record of late Holocene and recent climate change from a lake near Ny-Ålesund, Svalbard. Boreas 40(3):468-480.

86.                 Johansen BE, Karlsen SR, & Tømmervik H (2011) Vegetation mapping of Svalbard utilising Landsat TM/ETM+ data. Polar Record 48(1):47-63.

87.                 Jones VJ & Birks HJB (2004) Lake-sediment records of recent environmental change on Svalbard: results of diatom analysis. Journal of Paleolimnology 31:445-466.

88.                 Jongman RH, Ter Braak CJF, & van Tongeren OFR (1995) Data analysis in community and landscape ecology (Cambridge University Press, Cambridge) p 299.

89.                 Juggins S (2009) rioja: Analysis of Quaternary Science Data, R package version 0.5-6. (Online available at: http://cran.r-project.org/package=rioja).

90.                 Julius ML & Theriot EC (2010) The diatoms: a primer. The Diatoms. Applications for the Environmental and Earth Sciences, eds Smol JP & Stoermer EF (Cambridge University Press, New York), pp 8-22.

91.                 Kástovská K, Elster J, Stibal M, & Santrucková H (2005) Microbial assemblages in soil microbial succession after glacial retreat in Svalbard (high arctic). Microbial ecology 50(3):396-407.

92.                 Keatley BE, Douglas MSV, & Smol JP (2006) Early-20th Century Environmental Changes Inferred Using Subfossil Diatoms from a Small Pond on Melville Island, N.W.T., Canadian High Arctic. Hydrobiologia 553(1):15-26.

93.                 Kim GH, Klockkova TA, Han JW, Kang S-H, Choi HG, Chung KW, & Kim SJ (2011) Freshwater and Terrestrial Algae from Ny-Ålsedund and Blomstrandhalvøya Island (Svalbard). Arctic 64(1):25-31.

94.                 Kim GH, Klockkova TA, & Kang SH (2008) Notes on feshwater and terrestrial algae from Ny-Ålesund, Svalbard (high Arctic sea area). Journal of Environmental Biology 29(4):485-491.

95.                 Kingston JCP (1982) Palaeolimnology of a Lake and Adjacent Fent in Southeastern Labrador: Evidence from Diatom assemblages. 7th diatom-symposium:443-453.

96.                 Kłysz P, Lindner L, Marks L, & Wysokinski L (1989) Late Pleistocene and Holocene relief modelling in the Ebbadalen-Nordenskiöldbreen region in Olav V Land, central Spitsbergen. Polish Polar Research 10(3):277-301.

97.                 Komárek J, Kováčik L, Elster J, & Komárek O (2012) Cyanobacterial diversity of Petuniabukta, Billefjorden, central Spitsbergen. Polish Polar Research 33(4):347-368.

98.                 Krammer K (1997) Die cymbelloiden Diatomeen. Eine Monographie der weltweit bekannten Taxa. Teil 1. Allgemeins und Encyonema Part (J. Cramer, Berlin/Stuttgart) p 382.

99.                 Krammer K (2001) Navicula sensu stricto. 10 Genera Separated from Navicula sensu lato. Frustulia. Diatoms of Europe, ed Lange-Bertalot H (A. R. G. Gantner Verlag K. G, Rugell), Vol 2, p 526.

100.              Krammer K (2002) Cymbella. Diatoms of Europe, ed Lange-Bertalot H (A. R. G. Gantner Verlag K. G., Rugell), Vol 3, p 584.

101.              Krammer K & Lange-Bertalot H (1986) Bacillariophyceae 1. Teil Naviculaceae. In: Ettl H, Gerloff J, Heynig H, Mollenhauer D (Hrsgb.), Süßwasserflora von Mitteleuropa, 2/1. (G. Fisher Verlag, Stuttgart/New York) p 876.

102.              Krammer K & Lange-Bertalot H (1988) Bacillariophyceae 2. Teil Bacillariaceae, Epithemiaceae, Surirellaceae. In: Ettl H, Gerloff J, Heynig H, Mollenhauer D (Hrsgb.), Süßwasserflora von Mitteleuropa, 2/2 (Fisher Verlag, Stuttgart/New York) p 596.

103.              Krammer K & Lange-Bertalot H (1991) Bacillariophyceae 3. Teil Centrales, Fragilariaceae, Eunotiaceae. In: Ettl H, Gerloff J, Heynig H, Mollenhauer D (Hrsgb.), Süßwasserflora von Mitteleuropa, 2/3 (G. Fisher Verlag, Stuttgart/New York) p 576.

104.              Krammer K & Lange-Bertalot H (1991) Bacillariophyceae 4. Teil Achnanthaceae. Kritischen Ergänzungen zu Navicula (Lineolatae) und Gomphonema. In: Ettl H, Gerloff J, Heynig H, Mollenhauer D (Hrsgb.), Süßwasserflora von Mitteleuropa, 2/4 (G. Fisher Verlag, Stuttgart/New York) p 437.

105.              Krasske G (1938) Beiträge zur Kenntnis der Diatomeen-Vegetation von Island und Spitzbergen. Archives of Hydrobiology 33:503-553.

106.              Lagerstedt NGW (1873) Sötvattens-Diatomaceer från Spetsergen och Beeren Eiland. Bihang Till Kongliga Svenska Vetenskaps-Akademiens Handlingar 1:1-52.

107.              Laing TE & Smol JP (2003) Late Holocene environmental changes inferred from diatoms in a lake on the western Taimyr Peninsula, northern Russia. Journal of Paleolimnology 30:231-247.

108.              Lambeck K (1996) Limits on the areal extent of the Barents Sea ice sheet in Late Weichselian time. Global and Planetary Change 12:41-51.

109.              Landvik JY, Bondevik S, Elverhøi A, Fjeldskaar W, Mangerud J, Salvigsen O, Siegert MJ, Svendsen J-I, & Vorren TO (1998) The last glacial maximum on Svalbard and the Bartens Sea area: ice sheet extent and configuration. Quaternary Science Reviews 17:43-75.

110.              Landvik JY, Ingólfsson Ó, Mienert J, Lehman SJ, Solheim A, Elverhøi A, & Ottesen D (2005) Rethinking Late Weichselian ice-sheet dynamics in coastal NW Svalbard. Boreas 34(1):7-24.

111.              Lange-Bertalot H (1997) Frankophila, Mayamaea und Fistulifera: drei neue gattungen der klasse Bacillariophyceae. Archiv für Protistenkunde 148(1-2):65-76.

112.              Láska K, Witoszová D, & Prošek P (2012) Weather patterns of the coastal zone of Petuniabukta, central Spitsbergen in the period 2008–2010. Polish Polar Research 33(4):297-318.

113.              Levkov Z (2009) Amphora sensu lato. Diatoms of Europe, ed Lange-Bertalot H (A. R. G. Gantner Verlag K. G., Rugell), Vol 5, p 916.

114.              Lien L, Henriksen A, & Traaen TS (1995) Critical loads of acidity to surface waters: Svalbard. The Science of the Total Environment 160/161:703-713.

115.              Lim DSS, Smol JP, & Douglas MSV (2008) Recent environmental changes on Bank Island (N. W. T., Canadian Arctic) quantified using fossil diatom assemblages. Journal of Paleolimnology 40:385-398.

116.              Lindner L & Marks L (1993) Middle and Late Quaternary evolution of Spitsbergen against global changes. Polish Polar Research 14(3):221-241.

117.              Liška J & Soldán Z (2004) Alien vascular plants recorded from the Barentsbrug and Pyramiden settlements, Svalbard. Preslia 76:279-290.

118.              Lortie G & Richard JH (1986) Late-Glacial diatom and pollen stratigraphy from Lake Boucané, Southeastern Québec, Canada. Proceedings of the Eighth Diatom Symposium 1984, ed Richard M (Koeltz Scientific Books, Koeningstein), pp 687-697.

119.              Lotter AF & Bigler C (2000) Do diatoms in the Swiss Alps reflect the length of ice-cover? Aquatic Science 62:125-141.

120.              Lowe CW (1923) Report of the Canadian Arctic Expedition 1913–18. Part A: freshwater algae and freshwater diatoms, Southern Party 1913–1916. (F. A. Acland, Printer of the King’s Most Excellent Majesty, Ottowa).

121.              Lowe RL, Kociolek P, Johansen JR, Van De Vijver B, Lange-Bertalot H, & Kopalová K (2014) Humidophila gen. nov., a new genus for a group of diatoms (Bacillariophyta) formerly within the genus Diadesmis: species from Hawai'i, including one new species. Diatom Research 29:1-10.

122.              Luoto TP, Nevalainen L, Kubischta F, Kultti S, Knudsen KL, & Salonen V-P (2011) Late Quaternary Ecological Turnover in High Arctic Lake Einstaken, Nordaustlandet, Svalbard (80°N). Geografiska Annaler: Series A, Physical Geography 93(4):337-354.

123.              Majewski W, Szczuciński W, & Owski MZ (2009) Interactions of Arctic and Atlantic water-masses and associated environmental changes during the last millennium, Hornsund (SW Svalbard). Boreas 38:529-544.

124.              Mangerud J, Bolstad M, Elgersma A, Helliksen D, Landvik JY, Lønne I, Lycke AK, Salvigsen O, Sandahl T, & Svendsen JI (1992) The Last Glacial Maximum on Spitsbergen, Svalbard. Quaternary Research 38:1-31.

125.              Mann DG (1999) The species concept in diatoms. Phycologia 38(6):437-495.

126.              Mann DG (2010) Discovering diatom species: is a long history of disagreements about species-level taxonomy now at an end? Plant Ecology and Evolution 143(3):251-264.

127.              Mann DG, Chepurnov VA, & Droop SJM (1999) Sexuality, incompatibility, size varation, and preferential polyandry in natural populations and clones of Sellaphora pupula (Bacillariophyceae). Journal of Phycology 35:152-170.

128.              Mann DG & Vanormelingen P (2013) An inordinate fondness? The number, distributions, and origins of diatom species. The Journal of eukaryotic microbiology 60(4):414-420.

129.              Mann ME (2002) Medieval climatic optimum. Encyclopedia of Global Environmental Change, ed Munn T (John Wiley, London), Vol 1, pp 514-516.

130.              Marciniak B (1979) Dominant diatoms from Late-Glacial and Holocene lacustrine sediments in northern Poland. Beihefte zu Nova Hedwigia 64:411-426.

131.              Mazurek M, Paluszkiewicz R, Rachlewicz G, & Zwoliński Z (2012) Variability of Water Chemistry in Tundra Lakes, Petuniabukta Coast, Central Spitsbergen, Svalbard. The Scientific World Journal 2012:1-13.

132.              Metzeltin D & Witkowski A (1996) Diatomeen der Bären-Insel. Iconographia Diatomologica, ed Lange-Bertalot H (Koeltz Scientific Books, Königstein/Germany), Vol 4, p 286.

133.              Michelutti N, Douglas MSV, & Smol JP (2003) Diatom response to recent climatic change in a high arctic lake (Char Lake, Cornwallis Island, Nunavut). Global and Planetary Change 38(3-4):257-271.

134.              Moore JW (1974a) Benthic algae of southern Baffin Island. I. Epipelic communities in rivers. Journal of Phycology 10:50-57.

135.              Moore JW (1974b) Benthic algae of southern Baffin Island. II. The epipelic communities in temporary pools. Journal of Ecology 62:809-819.

136.              Moore JW (1974c) Benthic algae of southern Baffin Island. III. Epilithic and epiphytic communities. Journal of Phycology 10:456-462.

137.              Morales EA & Manoylov KM (2009) Mayamaea cahabaensis sp. nov. (Bacillariophyceae), a New Freshwater Diatom from Streams in the Southern United States. Proceedings of the Academy of Natural Sciences of Philadelphia 158(1):49-59.

138.              Nagumo T (2003) Taxonomic studies of the subgenus Amphora Cleve of the genus Amphora (Bacillariophyceae) in Japan. Bibliotheca Diatomologica, eds Lange-Bertalot H & Kociolek P (J. Cramer, Berlin/Stuttgart, Germany), Vol 49, p 265.

139.              Novais MH, Jüttner I, Van de Vijver B, Morais MM, Hoffman L, & Ector L (2014) Morphological diversity within the Achnanthidium minutissimum species complex (Bacillariophyta): comparison between type material and new Portugese species. Phytotaxa in press.

140.              Østrup E (1897a) Ferskvands-Diatomeer fra Öst Grönland. Meddelelser om Grönland 15:251-290.

141.              Østrup E (1897b) Kyst-Diatoméer fra Grönland. Meddelelser om Grönland 15:305-362.

142.              Østrup E (1910) Diatoms from North-East Greenland. Meddelelser om Grönland 43:199-256.

143.              Overpeck J (1997) Arctic Environmental Change of the Last Four Centuries. Science 278(5341):1251-1256.

144.              Øvstedal DO, Tønsberg T, & Elvebakk A (2009) The lichen flora of Svalbard. Sommerfeltia 33:1-393.

145.              Paul CA, Douglas MSV, & Smol JP (2010) Diatom-inferred Holocene climatic and environmental changes in an unusually subsaline high Arctic nunatak pond on Ellesmere Island (Nunavut, Canada). Journal of Paleolimnology 44(4):913-929.

146.              Paul CA, Rühland KM, & Smol JP (2010) Diatom-inferred climatic and environmental changes over the last ∼9000 years from a low Arctic (Nunavut, Canada) tundra lake. Palaeogeography, Palaeoclimatology, Palaeoecology 291(3-4):205-216.

147.              Paull TM, Hamilton PB, Gajewski K, & LeBlanc M (2008) Numerical analysis of small Arctic diatoms (Bacillariophyceae) representing the Staurosira and Staurosirella species complexes. Phycologia 47(2):213-224.

148.              Perren BB, Bradley R, S., & Francus P (2003) Rapid Lacustrine Response to Recent High Arctic Warming: A Diatom Record from Sawtooth Lake, Ellesmere Island, Nunavut. Arctic, Antarctic, and Alpine Research 35(3):271-278.

149.              Perren BB, Douglas MSV, & Anderson NJ (2009) Diatoms reveal complex spatial and temporal patterns of recent limnological change in West Greenland. Journal of Paleolimnology 42(2):233-247.

150.              Perren BB, Massa C, Bichet V, Gauthier E, Mathieu O, Petit C, & Richard H (2012) A paleoecological perspective on 1450 years of human impacts from a lake in southern Greenland. The Holocene 22(9):1025-1034.

151.              Petersen JB (1924) Fresh water algae from the north coast of Greenland collected by the late Dr. Th. Wulff. Den II Thule Exped. til Groenlands Nordkyst (1916–18). Meddelelser om Grønland 64:307-319.

152.              Picińska-Fałtynowicz J (1988) Freshwater benthic diatoms from the south-western part of the Horsnund fiord area, SW Spitsbergen. Polar Research 6:19-34.

153.              Pinseel E, Kopalová K, & Van de Vijver B (2014) Gomphonema svalbardense sp. nov., a new freshwater diatom species (Bacillariophyta) from the Arctic Region. Phytotaxa 170(4):250-258.

154.              Podritske B & Gajewski K (2007) Diatom community response to multiple scales of Holocene climate variability in a small lake on Victoria Island, NWT, Canada. Quaternary Science Reviews 26(25-28):3179-3196.

155.              Ponader K, Pienitz R, Vincent W, & Gajewski K (2002) Limnological conditions in a subarctic lake (nothern Québec, Canada) during the late Holocene: analyses based on fossil diatoms. Journal of Paleolimnology 27:353-366.

156.              Potapova M & Hamilton PB (2007) Morphological and Ecological Variation within the Achnanthidium minutissimum (Bacillariophyceae) Species Complex. Journal of Phycology 43(3):561-575.

157.              Prach K, Klimešová J, Košnar J, Redčenko O, & Hais M (2012) Variability of contemporary vegetation around Petuniabukta, central Spitsbergen. Polish Polar Research 33(4):383-394.

158.              Prach K, Košnar J, Klimešová J, & Hais M (2010) High Arctic vegetation after 70 years: a repeated analysis from Svalbard. Polar Biology 33(5):635-639.

159.              Prach K & Rachlewicz G (2012) Succession of vascular plants in front of retreating glaciers in central Spitsbergen. Polish Polar Research 33(4):319-328.

160.              Quijano-Scheggia SI, Garcés E, Lundholm N, Moestrup Ø, Andree K, & Camp J (2009) Morphology, physiology, molecular phylogeny and sexual compatibility of the cryptic Pseudo-nitzschia delicatissima complex (Bacillariophyta), including the description of P. arenysensis sp. nov. Phycologia 48(6):492-509.

161.              R Development Core Team (2010). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0, URL http://www.Rproject.org/.

162.              Rachlewicz G, Szczuciński W, & Ewertowski M (2007) Post-"Little Ice Age" retreat rates of glaciers around Billefjorden in central Spitsbergen, Svalbard. Polish Polar Research 28(3):159-186.

163.              Raven PH, Evert RF, & Eichhorn SE (2005) Biology of Plants (W. H. Freeman and Company, USA) 7 Ed p 686.

164.              Reimer PJ, Bard E, Bayliss A, Beck JW, Blackwell PG, Bronk RC, Buck CE, Cheng H, Edwards RL, Friedrich M, Grootes PM, Guilderson TP, Haflidason H, Hajdas I, Hatté C, Heaton TJ, Hogg AG, Hughen KA, Kaiser KF, Kromer B, Manning SW, Niu M, Reimer RW, Richards DA, Scott EM, Southon JR, Turney CSM, & van der Plicht J (2013) IntCal13 and MARINE13 radiocarbon age calibration curves 0-50000 years cal BP Radiocarbon 55(4):DOI: 10.2458/azu_js_rc.2455.1694.

165.              Rose NL, Rose CL, Boyle JF, & Appleby PG (2004) Lake-sediment evidence for local and remote sources of atmospherically deposited pollutants on Svalbard. Journal of Paleolimnology 31:49-513.

166.              Round FE & Bukhtiyarova L (1996) Four new genera based on Achnanthes (Achnanthidium) together with a re-definition of Achnanthidium. Diatom Research 11(2):345-361.

167.              Round FE, Crawford RM, & Mann DG (1990) The Diatoms. Biology & Morphology of the Genera (Cambridge University Press, UK) p 747.

168.              Rouse WR, Douglas MSV, Hecky RE, Hershey AE, Kling GW, Lesack L, Marsh P, McDonald M, Nicholson BJ, Roulet NT, & Smol JP (1997) Effects of climate change on the freshwaters of Arctic and Subarctic North America. Hydrological Processes 11:873-902.

169.              Rozema J, Boelen P, Doorenbosch M, Bohncke S, Blokker P, Boekel C, Broekman RA, & Konert M (2006) A vegetation, climate and environment reconstruction based on palynological analyses of high arctic tundra peat cores (5000–6000 years BP) from Svalbard. Plant Ecology 182:155-173.

170.              Rühland K & Smol JP (2005) Diatom shifts as evidence for recent Subarctic warming in a remote tundra lake, NWT, Canada. Palaeogeography, Palaeoclimatology, Palaeoecology 226(1-2):1-16.

171.              Rühland KM, Priesnitz A, & Smol JP (2003) Paleolimnological Evidence from Diatoms for Recent Environmental Changes in 50 Lakes across Canadian Arctic Treeline. Arctic, Antarctic, and Alpine Research 35(1):110-123.

172.              Sabbe K, Verleyen E, Hodgson DA, Vanhoutte K, & Vyverman W (2003) Benthic diatom flora of freshwater and saline lakes in the Larsemann Hills and Rauer Islands, East Antarctica. Antarctic Science 15(2):227-248.

173.              Salvigsen O, Forman SL, & Miller GH (1992) Thermophilous molluscs on Svalbard during the Holocene and their paleoclimatic implications. Polar Research 11(1):1-10.

174.              Sarmaja-Korjonen K, Nyman M, Kultti S, & Väliranta M (2006) Palaeolimnological Development of Lake Njargajavri, Northern Finnish Lapland, in a Changing Holocene Climate and Environment. Journal of Paleolimnology 35(1):65-81.

175.              Schindler DW & Smol JP (2006) Cumulative Effects of Climate Warming and Other Human Activities on Freshwaters of Arctic and Subarctic North America. A Journal of the Human Environment 35(4):160-168.

176.              Sheath RG, Havis M, Hellebust JA, & Hutchinson TC (1982) Effects of long-term natural acidification on the algal communities of tundra ponds at the Smoking Hills, N.W.T., Canada. Canadian Journal of Botany 60:58-72.

177.              Sims PA, Mann DG, & Medlin LK (2006) Evolution of the diatoms: insights from fossil, biological and molecular data. Phycologia 45(4):361-402.

178.              Smith IR (2002) Diatom-based Holocene paleoenvironmental records from continental sites on northeastern Ellesmere Island, high Arctic, Canada. Journal of Paleolimnology 27:9-28.

179.              Smol JP (1983) Paleophycology of a high arctic lake near cape Herschel, Ellesmere Island. Canadian Journal of Botany 61:2195-2204.

180.              Smol JP (1985) The ratio of diatom frustules to chrysophycean statospores: A usefule paleolimnological index. Hydrobiologia 123(3):199-208.

181.              Smol JP & Cumming BF (2000) Tracking long-term changes in climate using alga indicators in lake sediments. Journal of Phycology 36:986-1011.

182.              Smol JP & Douglas MS (2007) Crossing the final ecological threshold in high Arctic ponds. Proceedings of the National Academy of Sciences of the United States of America 104(30):12395-12397.

183.              Smol JP & Douglas MSV (2007) From controversy to consensus: making the case for recent climate change in the Arctic using lake sediments. Frontiers in Ecology and the Environment 5(9):466-474.

184.              Smol JP & Stoermer EF (2010) The Diatoms: Applications for the Environmental and Earth Sciences (Cambridge University Press, New York) p 667.

185.              Smol JP, Wolfe AP, Birks HJ, Douglas MS, Jones VJ, Korhola A, Pienitz R, Ruhland K, Sorvari S, Antoniades D, Brooks SJ, Fallu MA, Hughes M, Keatley BE, Laing TE, Michelutti N, Nazarova L, Nyman M, Paterson AM, Perren B, Quinlan R, Rautio M, Saulnier-Talbot E, Siitonen S, Solovieva N, & Weckstrom J (2005) Climate-driven regime shifts in the biological communities of arctic lakes. Proceedings of the National Academy of Sciences of the United States of America 102(12):4397-4402.

186.              Sorvari S & Korhola A (1998) Recent diatom assemblage changes in subarctic Lake Saanajärvi, NW Finnish Lapland, and their paleoenvironmental implications. Journal of Paleolimnology 20:205-215.

187.              Sorvari S, Korhola A, & Thompson R (2002) Lake diatom response to recent Arctic warming in Finnish Lapland. Global Change Biology 8:171-181.

188.              Souffreau C, Vanormelingen P, Sabbe K, & Vyverman W (2013) Tolerance of resting cells of freshwater and terrestrial benthic diatoms to experimental desiccation and freezing is habitat-dependent. Phycologia 52(3):246-255.

189.              Souffreau C, Vanormelingen P, Van de Vijver B, Isheva T, Verleyen E, Sabbe K, & Vyverman W (2013) Molecular evidence for distinct Antarctic lineages in the cosmopolitan terrestrial diatoms Pinnularia borealis and Hantzschia amphioxys. Protist 164(1):101-115.

190.              Souffreau C, Vanormelingen P, Verleyen E, Sabbe K, & Vyverman W (2010) Tolerance of benthic diatoms from temperate aquatic and terrestrial habitats to experimental desiccation and temperature stress. Phycologia 49(4):309-324.

191.              Spaulding SA, Kociolek JP, & Wong D (1999) A taxonomic and systematic revision of the genus Muelleria (Bacillariophyta). Phycologia 38:314-341.

192.              Stange R (2008) Spitsbergen - Svalbard. A complete guide around the archipelago (Druckerei Karl Keuer, Bützow) p 495.

193.              Stevenson AC, Juggins S, Birks HJB, Anderson DS, Anderson NJ, Battarbee RW, Berge F, Davis RB, Flower RJ, Haworth EY, Jones VJ, Kingston JC, Kreiser AM, Line JM, Munro MAR, & Renberg I (1991) The surface water acidification project paleolimnology programme: modern diatom/lake water chemistry data-sets (Ensis, London).

194.              Svendsen JI & Mangerud J (1992) Paleoclimatic inferences from glacial fluctuations on Svalbard during the last 20 000 years. Climate Dynamics 6:213-220.

195.              Svendsen JI & Mangerud J (1997) Holocene glacial and climatic variations on Spitsbergen, Svalbard. The Holocene 7(1):45-57.

196.              Svendsen JI, Mangerud J, Elverhøi A, Solheim A, & Schüttenhelm RTE (1992) The Late Weichselian glacial maximum on western Spitsbergen inferred from offshore sediment cores. Marine Geology 104:1-17.

197.              Szczuciński W & Rachlewicz G (2007) Geological setting of the Petuniabukta Region. Landform Analysis 5:212-215.

198.              Szczuciński W, Zajączkowski M, & Scholten J (2009) Sediment accumulation rates in subpolar fjords – Impact of post-Little Ice Age glaciers retreat, Billefjorden, Svalbard. Estuarine, Coastal and Shelf Science 85(3):345-356.

199.              ter Braak CJF & Smilauer P (2002) CANOCO Reference Manual and Users Guide to Canoco for Windows: Software for Canonical Community Ordination (Version 4.5) (USA: Microcomputer Power, Ithaca, NY).

200.              Thomasson K (1958) Zur Planktonkunde Spitzbergens. Hydrobiologia 12:226-236.

201.              Thomasson K (1961) Zur Planktonkunde Spitsbergens. 2. Hydrobiologia 18:192-198.

202.              Tomczyk A & Ewertowski M (2010) Changes of Arctic landscape due to human impact, north part of Billefjorden area, Svalbard. Quaestiones Geographicae 29(1):75-83.

203.              Trobajo R, Rovira L, Ector L, Wetzel CE, Kelly M, & Mann DG (2013) Morphology and identity of some ecologically important small Nitzschia species. Diatom Research 28(1):37-59.

204.              Tyler PA (1996) 13. Endemism in freshwater algae. Hydrobiologia 336:127-135.

205.              Van de Vijver B, Beyens L, & Lange-Bertalot H (2004) The Genus Stauroneis in the Arctic and (Sub-)Antarctic Regions. Bilbiotheca Diatomologica, eds Lange-Bertalot H & Kociolek P (J. Cramer, Berlin/Stuttgart), Vol 51, p 317.

206.              Van de Vijver B, Gremmen NJM, & Beyens L (2005) The genus Stauroneis (Bacillariophyceae) in the Antarctic region. Journal of Biogeography 32(10):1791-1798.

207.              Van de Vijver B & Kopalová K (2014) Four Achnanthidium species (Bacillariophyta) formerly identified as Achnanthidium minutissimum from the Antarctic Region. European Journal of Taxonomy 79:1-19.

208.              Van de Vijver B, Ledeganck P, & Beyens L (2002) Three new species of Diadesmis from soils of Ile de la Possession (Crozet Archipelago, Subantarctic). Cryptogamie Algologie 23:333-341.

209.              Van de Vijver B, Ledeganck P, Potters G, & Beyens L (1999) Diatom communities from alkaline environments of the Brøgger peninsula, north-west Spitsbergen. Nova Hedwigia 68(1/2):93-115.

210.              Van de Vijver B & Mataloni G (2008) New and interesting species in the genus Luticola D.G. Mann (Bacillariophyta) from Deception Island (South Shetland Islands). Phycologia 47:451-467.

211.              Van de Vijver B, Moravcová A, Kusber W-H, & Neustupa J (2013) Analysis of the type material of Pinnularia divergentissima (Grunow in Van Heurck) Cleve (Baccilariophyceae). Fottea 13(1):1-14.

212.              Van de Vijver B, Van Kerckvoorde A, & Beyens L (2003) Freshwater and terrestrial moss diatom assemblages of the Cambridge Bay area, Victoria Island (Nunavut, Canada). Nova Hedwigia 76:225-243.

213.              Van der Werff A (1955) A new method of concentrating and cleaning diatoms and other organisms. Verhandlungen Internationalen Vereinigung für Theoretische und Angewandte Limnologie. 2:276-327.

214.              Van Heurck H (1880-1885) Synopsis des Diatomées de Belgique (Ducaju & Cie, Anvers, Belgium).

215.              Van Kerckvoorde A (2002) Testate amoebae and diatoms in the Zackenberg area (Northeast Greenland): a study of their assemblages, recent ecology and palaeo-ecology in a High Arctic region. PhD-thesis (University of Antwerp).

216.              Van Kerckvoorde A, Trappeniers K, Nijs I, & Beyens L (2000) The epiphytic diatom assemblages from terrestrial mosses in Zackenberg (Northeast Greenland). Systematics and Geography of Plants 70(2):300-314.

217.              Vanormelingen P, Chepurnov VA, Mann DG, Cousin S, & Vyverman W (2007) Congruence of morphological, reproductive and ITS rDNA sequence data in some Australasian Eunotia bilunaris (Bacillariophyta). European Journal of Phycology 42(1):61-79.

218.              Vanormelingen P, Verleyen E, & Vyverman W (2007) The diversity and distribution of diatoms: from cosmopolitanism to narrow endemism. Biodiversity and Conservation 17(2):393-405.

219.              Vyverman W, Verleyen E, Sabbe K, Vanhoutte K, Sterken M, Hodgson DA, Mann DG, Juggins S, Van de Vijver B, Jones V, Flower R, Roberts D, Chepurnov VA, Kilroy C, Vanormelingen P, & De Wever A (2007) Historical processes constrain patterns in global diatom diversity. Ecology 88(8):1924-1931.

220.              Walker M (2005) Dating Using Anually Banded Records. Quaternary Dating Methods,  (John Wiley & Sons, Ltd, West Sussex, England), pp 121-156.

221.              Walker M (2005) Radiometric Dating 1: Radiocarbon Dating. Quaternary Dating Methods,  (John Wiley & Sons Ltd, West Sussex, England), pp 17-55.

222.              Werner D (1977) The Biology of Diatoms. Botanical Monographs, ed Werner D (University of California Press), Vol 13. p 498.

223.              Willén T (1980) Phytoplankton from lakes and pools on Vestspitsbergen. Acta phytogeographica suecica 68:173-188.

224.              Williams DM & Round FE (1987) Revision of the genus Fragilaria. Diatom Research 2(2):267-288.

225.              Winder M, Reuter JE, & Schladow SG (2009) Lake warming favours small-sized planktonic diatom species. Proceedings of the Royal Society B: Biological Sciences 276(1656):427-435.

226.              Wohlfart B, Lemdahl G, Olsson S, Persoon T, Snowball I, Ising J, & Jones V (1995) Early Holocene environment on Bjørnøya (Svalbard) inferred from multidisciplinary lake sediment studies. Polar Research 14(2):253-275.

227.              Zanon V (1929) Diatomee della Baia Del Re (Swalbard). Memorie della Pontificia Accademia delle Scienze, Nuovi Lincei, Serie II 12:419-464.

228.              Zeeb BA & Smol JP (2001) Chrysophyte scales and cysts. Tracking Environmental Changes Using Lake Sediments. Volume 3: Terrestrial, Algal and Siliceous Indicators, eds Smol JP, Birks HJB, & Last WM (Kluwer Academic Publishers, Dordrecht, The Netherlands), pp 203-223.

229.              Zwolinski Z, Mazurek M, Paluszkiewicz R, & Rachlewicz G (2008) The matter fluxes in the geoecosystem of small tundra lakes, Petuniabukta coast, Billefjorden, Central Spitsbergen. Zeitschrift fur Geomorphologie 52(1):79-101.

Universiteit of Hogeschool
Master of science in de Biologie: Ecologie & Milieu
Publicatiejaar
2014
Kernwoorden
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