Arctic plant ecology: From tundra to polar desert in Svalbard - Unis

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Content Arctic plant ecology: From tundra to polar desert in Svalbard – summary Inger Greve Alsos, Christian Körner and David Murray 1. Biodiversity in the high Arctic: species richness at selected sites in Svalbard, 7880°N Henrik Antonsson, Marte Holten Jørgensen and Ane Christensen Tange 2. Life in the Arctic – a struggle for survival? Simone Lang, Merete Wiken Dees and Kathrin Bockmühl 3. Recruitment along retreating glaciers Unni Vik, Ingelinn Aarnes and Eike Müller 4. High nutrient levels can compensate for the growthlimiting effect of low temperatures Elke Morgner and Christian E. Pettersen 5. Reproductive allocation in the high Arctic Heike Baldeweg and Emma Bengtsson 6. Freezing resistance in high arctic plant species of Svalbard in midsummer Christian Körner, Inger Greve Alsos and AB326 students 2 3 11 33 55 73 83 93
Arctic plant ecology: From tundra to polar desert in Svalbard – summary Inger Greve Alsos 1 , Christian Körner 2 and David Murray 3 1 UNIS – The University Centre in Svalbard, P.O.Box 156, NO9171 Longyearbyen, Norway, 2 Institute of Botany, University of Basel, Schönbeinstrasse 6, CH4056 Basel, Switzerland, 3 University of Alaska Museum of the North, Fairbanks, Alaska, 997756960 USA Introduction Within the Arctic, there is a strong climatic gradient from the southern arctic tundra zone forest ecotone to the polar desert zone found to the very edge of the arctic landmass (Walker et al. 2005). Three of these zones are present on Svalbard, the mid arctic tundra zone (zone C), the northern arctic tundra zone (zone B) and the polar desert zone (zone A, Elvebakk 2005). The mean air temperature during the warmest month in these three zones in Svalbard are 46 ºC , 2.54 ºC and 12.5 ºC, respectively (Elvebakk 2005). Because temperature is a major factor determining plant diversity in the Arctic (Rannie 1986, Walker 1995), global climate warming is expected to have an impact on arctic flora and vegetation. During our course, the focus was thus on changes in plant diversity, plant distribution, and plant traits along the climatic gradient from bioclimatic zone C to A. Factors other than temperature have strong impacts on plant life and diversity, e.g. soil moisture (Raup 1969, Gould & Walker 1999), soil acidity (Gould & Walker 1999, Gough et al. 2000, Karlsen & Elvebakk 2003), nutrient input (Körner 2003), plant productivity (Fox 1992, Jonasson 1992, van der Welle et al. 2003), age of the terrain (Matthews 1992, Moreau 2005) and natural disturbance (Raup 1969). Our site selection covered a suite of such covariables. Arctic plant communities are expected to undergo species turnover due to climate change (Walker et al.2006, Kullman 2000, Alsos et al. 2007). This could cause local loss or increase in plant diversity. Although more than 100 hypotheses have been raised to address factors determining biodiversity (Grime 1973, Palmer 1994), variance in species diversity is often poorly explained by predictor variables (Grace 1999). Understanding this issue is importance to predicting short and longterm effects of climate change on arctic tundra. In project 1, we investigated how soil temperature, soil moisture, soil pH, exposure, slope angle, bioclimatic zones, and productivity were related to vascular plant diversity in Svalbard. Species may have different amplitudes of tolerance to environmental factors (Raup 1969, Karlsen & Elvebakk 2003). Some have wide amplitudes, are broadly tolerant, whereas others have more narrow amplitude. The question is whether widespread species have a wide ecological amplitude or could they have a narrow tolerance for specific habitats, but these habitats are widespread? This is investigated in project 2. Special emphasis was on Euphrasia wettsteinii, a thermophilic annual which seems to have spread locally in Svalbard during recent years, a period with warmer than average temperatures. 3
Page 1: Arctic plant ecology: From tundra t
Page 5 and 6: localities in western and northern
Page 7 and 8: seamed to decrease from zone C to A
Page 9: Raup, H. M. 1965: The flowering pla
Page 12 and 13: them supporting his theory (e.g., H
Page 14 and 15: Site ID Table 1. Sites analysed in
Page 16 and 17: Table 2. Kendall’s τ correlation
Page 18 and 19: The RDA ordination (Fig. 4) showed
Page 20 and 21: al. (2007) found that at low temper
Page 22 and 23: Franzèn, D. & Molau, U. 1999: Vasc
Page 24 and 25: Tilman, D. 1982: Resource Competiti
Page 26 and 27: Juncus biglumis L. Luzula confusa L
Page 28 and 29: Puccinellia phryganodes (Trin.) Scr
Page 30 and 31: #Saxifraga nivalis L. *Saxifraga op
Page 32 and 33: *Coptidium lapponicum (L.) Tzvelev
Page 34 and 35: esponse curve. With rising temperat
Page 36 and 37: N Biscayarhuken Florabukta Reinsdyr
Page 38 and 39: of cold summers can be terminal for
Page 40 and 41: Results Ecological amplitudes of va
Page 42 and 43: A potential substrate area could be
Page 44 and 45: no. of districts 30 25 20 15 10 5 0
Page 46 and 47: tetragona, Erigeron humilis, Minuar
Page 48 and 49: with the species occurring on Svalb
Page 50 and 51: and substrate map show a clear occu
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Alsos, I. G. 2007: Frequent LongD
Page 54 and 55:
Walker, M., Wahren, C., Hollister,
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northern hemisphere (Brochmann et a
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an enclave of bioclimatic zone C wi
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Table 3. Formulas of the different
Page 62 and 63:
Figure 2. a: Cumulative number of s
Page 64 and 65:
Figure 4. Presence and absence of a
Page 66 and 67:
(2003), from which a highly signifi
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The intermediate stages seem to hav
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Svalbard in general. Moreover polyp
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Svoboda, J., Henry, G. H. R. 1987:
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limited by nutrient availability ra
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flower. Care was taken to measure o
Page 78 and 79:
Biomass Biomass per unit land area
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Luzula nivalis Juncus biglumis Drya
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References Arft, A. M., Walker, M.
Page 84 and 85:
partly lose their high altitude/lat
Page 86 and 87:
preferably grow in rosettes, which
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Forbs Graminoid Graminoids In grami
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latitude plants on Svalbard to keep
Page 92 and 93:
Elvebakk A. 1999: Bioclimatic delim
Page 94 and 95:
a climate description see Rønning
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Results and Discussion The minimum
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Table 2. Ranking of examined plant
Page 100:
References Biebl, R. 1968: Über W
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Arctic plant ecology: From tundra to polar desert in Svalbard - Unis

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