Engelskj.n.indd 317Engelskjøn et al. 2003: Polar Research 22(2), 317–339 The archipelago of Svalbard (74° 20' - 80° 50' N) (Fig. 1) is one of the world’s least impacted Arctic biomes, and it is an aim for Norwegian authorities to preserve it (Stortinget 2000). A plan for vege- tation protection has been proposed by the Gov- ernor of Svalbard (1999; see Alsos 2000) because the prevailing practice of protecting plant species, but not their habitats, had evident shortcomings (Thei sen & Brude 1998; Alsos 2000). The new plan (Miljøverndepartementet 2003) is a supple- ment to the national park system of Svalbard and implies protection of all plant life within circum- scribed geographical areas (Fig. 2). Svalbard harbours approximately 165 native vascular plant species (Elven & Elvebakk 1996). The Inner Arctic Fjord Zone of Spitsbergen (Fig. 1) is particularly rich in species and is favoured by frequently clear skies and elevated summer temperatures (Elvebakk 1985, 1989). Between 20 and 30 of Svalbard’s vascular plant species can be considered warmth-demanding compared to the rest of the archipelago’s fl ora (Engel skjøn 1987; Elvebakk 1989). Their few, small and disjunct present-day populations are Twenty of the most thermophilous vascular plant species in Svalbard and their conservation state Torstein Engelskjøn, Leidulf Lund & Inger Greve Alsos An aim for conservation in Norway is preserving the Svalbard archi- pelago as one of the least disturbed areas in the Arctic. Information on local distribution, population sizes and ecology is summarized for 20 thermophilous vascular plant species. The need for conservation of north- ern, marginal populations in Svalbard is reviewed, using World Conser- vation Union categories and criteria at a regional scale. Thirteen species reach their northernmost distribution in Svalbard, the remaining seven in the western Arctic. Nine species have 1 - 8 populations in Svalbard and are assigned to Red List categories endangered or critically endangered: Campanula rotundifolia, Euphrasia frigida, Juncus castaneus, Kobresia simpliciuscula, Rubus chamaemorus, Alchemilla glomerulans, Ranuncu- lus wilanderi, Salix lanata and Vaccinium uliginosum, the last four spe- cies needing immediate protective measures. Five species are classifi ed as vulnerable: Betula nana, Carex marina ssp. pseudolagopina, Luzula wahlenbergii, Ranunculus arcticus and Ranunculus pallasii. Six species are considered at lower risk: Calamagrostis stricta, Empetrum nigrum ssp. hermaphroditum, Hippuris vulgaris (only occurring on Bjørnøya), Juncus triglumis, Ranunculus lapponicus and Rhodiola rosea. The warmer Inner Arctic Fjord Zone of Spitsbergen supports most of the 20 target species and is of particular importance for conservation. Endan- gered or vulnerable species were found in a variety of edaphic conditions; thus, several kinds of habitats need protection. T. Engelskjøn, I. G. Alsos, Tromsø Museum, University of Tromsø, NO-9037 Tromsø, Norway, torstein@ tmu.uit.no; L. Lund, Phytotron, University of Tromsø, NO-9037 Tromsø, Norway. 318 Twenty thermophilous vascular plant species in Svalbard partly relicts of larger populations thought to have been established between 9000 and 4000 years ago, when the mean July temperature was 1 - 2 °C higher than at present (Birks 1991). The temp erature decline over the last 4000 years (Birks 1991) may have suppressed sexual repro- duction and caused fragmentation of popula tions and genetic bottlenecks (Alsos, Brochman et al. 2002; Alsos et al. 2003). Several thermophilous species rarely produce germinable seeds under the present climatic conditions and may thus have a reduced recruit ment following distur- bance (Nathorst 1883; Alsos et al. 2003; Cooper et al. in press). Increased human activity in the most species-rich parts of Sval bard (Hansen et al. 1996; Theisen & Brude 1998) may consti- tute a threat to the thermo philous species of the archipelago. Many records of these species are more or less buried in the literature. Plant records prior to Hadač (1944) were imprecise due to lack of topo- graphical maps. In spite of Svalbard having been frequently visited, documentation of uncommon species tended to be anecdotal. This paper is based on botanical surveys of Bjørnøya (Engel- skjøn & Schweitzer 1970; Engelskjøn 1987), parts of Spitsbergen (Engelskjøn et al. 1972; Hofmann & Thannheiser 1972; Thannheiser 1972; Dubiel 1990; Kuc & Dubiel 1995; Elven et al. 1990; Möl- ler & Thannheiser 1997; Möller 2000; Alsos, Lund et al. 2002), Nordaustlandet (Neilson 1968), Edge øya (Neilson 1970), Barentsøya (Hjelmstad 1981) and Svalbard as a whole (Elvebakk 1985, 1989; Engelskjøn 1986; Elven & Elvebakk 1996), as well as our recent fi eld investigations. Our aim is to assess the local distribution of 20 target species in relation to their presumed edaph- ic and thermal demands and their need of conser- vation measures to protect them. Also considered are the southern geographical range extensions of some of these species and their mainly low alpine altitudinal limits in northern Scandinavia (Engel- skjøn 1986, 1994). Fig. 1. Vegetation zones of Svalbard, adapted from Möller (2000). (The small island of Bjørnøya, about 250 km south of the main groups of islands, is not shown.) 319Engelskjøn et al. 2003: Polar Research 22(2), 317–339 Study area Svalbard is subdivided into provinces shown in Fig. 3. Also a part of the archipelago is the small island of Bjørnøya, about midway between the Norwegian mainland and the island of Spits- bergen. Methods Inclusion of species Apart from the 20 species treated here, at least 11 other vascular plant species in Svalbard may be considered thermophilous, e.g. Arctagros- tis latifolia (Rønning 1972), Botrychium bore- ale, B. lunaria (Elvebakk et al. 1994), Arenar- ia humifusa, Carex glacialis (Elven & Elvebakk 1996), Carex bigelowii (Elven & Elvebakk 2002), Cystopteris fragilis (Rønning 1972), Gentianel- la tenella (Elvebakk 1989), Juncus arcticus (Lid 1925, 1967), Taraxacum brachyceras (Elvebakk 1989) and Tofi eldia pusilla (Rønning 1972). How- ever, these rare species were insuffi ciently docu- mented or not seen by us. Conversely, at least two very rare species in Svalbard are adapted to cold conditions, viz. Ranunculus glacialis (Elven & Elvebakk 1996) and Sagina caespitosa (Lid 1962). Phytogeographical terms Zonal subdivision of Svalbard follows Möller (2000: 43) with respect to the Inner Arctic Fjord Zone of Spitsbergen (Fig. 1). In a circum-Arctic context we use the phytogeographical terms pre- sented in Table 1. Fig. 2. Extant and proposed pro- tected areas (national parks and nature reserves, excluding bird reserves) in Svalbard, exclud- ing Bjørnøya. Redrawn after Governor of Svalbard (1999) and Miljøverndepartementet (2003). 320 Twenty thermophilous vascular plant species in Svalbard Distribution, population sizes, and state of conservation Populations of species are recorded in Appen- dix 1 based on fi eld observations, botanical liter- ature, Norwegian university herbaria and person- al communications. Unpublished fi nds have been included. When more than one source reports the same fi nd, only the most precise one is quoted. Estimates of population size are based on occurrence within the local 1 × 1 km square of the Universal Transverse Mercator (UTMED50) grid. Populations are rated as small, medium or large, as delineated in Table 1. The term “popula- tion” here also includes subpopulations belonging to the same metapopulation. Red List categories are assessed according to the World Conserva- tion Union (IUCN 2001) at the regional scale of Svalbard. The proportions of populations protect- ed were reviewed according to extant and recent- ly established protected areas (Miljøverndeparte- mentet 2003; Fig. 2). Ecology Air temperatures for the growing season were compiled from climatological literature and from Engelskjøn (1986, 1987, 1994). Notes are pro- vided on mineral and/or organic substrata and hydrology of the habitats of each species. Accom- panying species are enumerated; nomenclature mainly follows Elvebakk & Hertel (1996), Elven & Elvebakk (1996), Frisvoll & Elvebakk (1996) and Gulden & Torkelsen (1996). Fig. 3. Thermophilous species per province in Svalbard (Bjørnøya not shown), given as the number of species / total number of observed populations of all 20 target species. See Fig. 1 for vegetation zones. Table 1. Defi nitions of phytogeographical terms and population size categories used in this paper. Term Defi nition Boreal The northern, wooded latitudinal zone. Arctic The entire or most of the treeless zone. Low Arctic Southern portion of the Arctic, with prominent Betula nana, medium-sized Salix spp., Ledum palustre, Vaccinium spp. or Empetrum spp., corresponding to Elvebakk’s (1985) Low Arctic Tundra Zone. High Arctic Northern portion of the Arctic, i.e. all lands north of the Low Arctic. Barents Sea region Svalbard, Franz Josef Land, Novaya Zemlya, Vaygach, Kolguyev and the polar Urals. Small population A closed stand less than 15 × 15 m; alternatively, scattered individuals or ramets within only one quarter of the 1 km UTM square. Medium population One or a few copious stands at least 15 × 15 m, or scattered individuals/ramets in more than one quarter of the 1 km UTM square. Large population Generally distributed and/or abundant within one or more 1 km UTM squares. No data No precise information is available on population size. 321Engelskjøn et al. 2003: Polar Research 22(2), 317–339 Results Table 2 summarizes worldwide northern limits, number of populations in Svalbard, and tenta- tive Red List categories. A more detailed account is provided in Appendix 1, which also specifi es populations protected under the current conser- vation plan for Svalbard (Miljøverndepartemen- tet 2003). State of conservation Red List categories are recorded in Table 2. Nine species are considered endangered or critically endangered in Svalbard; fi ve species are vulner- able, and six species are at lower risk. Accord- ing to the current protection plan, more than half of the known Svalbard populations of the follow- ing species are protected: Alchemilla glomeru- lans, Calamagrostis stricta, Carex marina ssp. pseudolagopina, Empetrum nigrum ssp. herm- aphroditum, Hippuris vulgaris, Juncus cas- taneus, Luzula wahlenbergii, Ranunculus arcti- cus, R. wilanderi, Rhodiola rosea, and Rubus chamaemorus. Fewer than half of the populations of Euphrasia frigida, Juncus triglumis, Kobresia simpliciuscula, Ranunculus lapponicus, R. pal- Table 2. Twenty thermophilous species in Svalbard. Population data from Appendix 1. Species Extant northern limit in Svalbard Northern limit outside of Svalbard No. of popula- tions % of pop- ulations protected Red List category at the regional level (IUCN 2001) Alchemilla glomerulans Sam. 74° 31' Bjørnøya 71° 10' Nordkapp, mainland Norway (Dahl 1934) 1 100 Critically endangered Betula nana L. 78° l5' Adventdalen 76° NE Greenland (Fredskild 1998) 39 0 Vulnerable Calamagrostis stricta (Timm) Koeler 79° 30' Liefdefjorden 74° 40' NE Greenland (Bay 1992) 108 53 Lower risk Campanula rotundifolia L. 78° 07' Colesbukta 75° 50' NE Greenland (Bay 1992) 4 0 Endangered Carex marina Dew. ssp. pseudolagopina (Sørensen) Böcher 79° 30' Liefdefjorden 83° N Greenland (Bay 1992) 16 100 Vulnerable Empetrum nigrum L. ssp. hermaphroditum (Hagerup) Böcher 80° 30' Nordaustlandet 79° 10' NW Greenland (Simmons 1909) ca. 80 54 Lower risk Euphrasia frigida Pugsley 79° 26' Bockfjorden 77° 20' NE Greenland (Bay 1992) 7 28 Endangered Hippuris vulgaris L. 74° 31' Bjørnøya 82° 13' N Greenland (Fredskild 1966) 22 100 Lower risk Juncus castaneus Sm. 78° 28' Gipsdalen 83° N Greenland (Bay 1992) 5 60 Endangered Juncus triglumis L. 79° 30' Wijdefjorden 83° N Greenland (Bay 1992) 39 41 Lower risk Kobresia simpliciuscula (Wahlenb.) Mack. 78° 56' Kongsfjorden 82° 01' N Greenland (Holmen 1957) 8 38 Endangered Luzula wahlenbergii Rupr. 78° 17' Adventfjorden 75°55' NE Greenland (Bay 1992) 14 50 Vulnerable Ranunculus arcticus R. Br. 79° 15' Krossfjorden 83° N Greenland (Bay 1992) 25 84 Vulnerable Ranunculus lapponicus L. 79° Wijdefjorden 73° Novaya Zemlya (Lynge 1924) 70 41 Lower risk Ranunculus pallasii Schlecht. 78° 25' Bohemanfl ya 73° Novaya Zemlya (Lynge 1924) 11 45 Vulnerable Raunculus wilanderi (Nath.) Á. & D. Löve 78° 27' Kapp Thordsen 73° Novaya Zemlya (Lynge 1924 – sp.?) 1 100 Critically endangered Rhodiola rosea L. 78° 45' Prins Karls Forland 75° 05' NE Greenland (Bay 1992) 30 100 Lower risk Rubus chamaemorus L. 78° 38' Ekmanfjellet 73° Novaya Zemlya (Lynge 1924) 9 67 Endangered Salix lanata L. 78° 12' Adventdalen 75° Taymyr (Tolmachev et al. 1996) 2 0 Extirpated (Kongsfjorden); critically endangered (Adventdalen) Vaccinium uliginosum L. 78° 39' Mimerdalen 81° 55' N Greenland (Holmen 1957) 5 20 Critically endangered 322 Twenty thermophilous vascular plant species in Svalbard lasii, and Vaccinium uliginosum are protected. None of the populations of Betula nana or Cam- panula rotundifolia, nor the only intact popula- tion of Salix lanata, are protected. Impact of climate Air temperatures and heat sums for July–August and June–September are summarized for Boreal or Arctic stations in northern Norway and Sval- bard (Table 3). The island of Hopen has a compa- rably cold climate, summer temperatures reach- ing only a few degrees above zero. The climate at the southern end of Spitsbergen, represent- ed by Hornsund, is comparable to Isfjord Radio and Bjørnøya. There is a sizeable difference in summer temperature between the coastal station Isfjord Radio, on the margin of the Middle Arctic Tundra Zone, and the Longyearbyen station in the Inner Arctic Fjord Zone (Fig. 1): degree-days (sum of mean diurnal temperatures) for July– August amount to 290 and 365, respectively. The thermophilous species in Svalbard general- ly require a heat sum exceeding 300 degree-days for July and August. The occurrence of these spe- cies in various parts of Spitsbergen is illustrated in Fig. 3. Edaphic requirements Based on observations in the fi eld, preferences of soil and hydrology are outlined for the 20 target species (Table 4). There is a considerable varia- tion along the gradients eutrophic—oligotrophic and drained—wet. Review of species Thirteen thermophilous species advance far- ther north in Svalbard than in other Arctic lands (Table 2). Seven species occurring in Svalbard reach their northern limits in Greenland: Carex marina ssp. pseudolagopina, Hippuris vulgaris, Juncus castaneus, J. triglumis, Kobresia simplici- uscula, Ranunculus arcticus and Vaccinium ulig- inosum. The following 20 target species are treat- ed in some detail with regard to their distribution Table 4. Twenty thermophilous vascular plant species in Svalbard according to edaphic gradients. Drained Moist Wet Calcareous (eutrophic) (none) Alchemilla glomerulans Kobresia simpliciuscula Carex marina ssp. pseudolagopina Juncus castaneus Juncus triglumis Mixed or intermediate (mesotrophic) Betula nana Campanula rotundifolia Ranunculus arcticus Rhodiola rosea Vaccinium uliginosum Euphrasia frigida Ranunculus wilanderi Salix lanata Calamagrostis stricta Hippuris vulgaris Ranunculus lapponicus Ranunculus pallasii Siliceous or humic (oligotrophic) Empetrum nigrum ssp. hermaphroditum Rubus chamaemorus Luzula wahlenbergii (none) Table 3. Temperatures (°C) and heat sums for the summer in Svalbard. Standard normals 1931–1960, if not otherwise stated. Data from Steffensen (1982) and Baranowski (1975). See also Aune (1993) for standard normals 1961–1990. Data for Tromsø and Vardø, northern Norway, included for comparison. Northern latitude Mean temperature (°C) Degree-days Jun. Jul. Aug. Sept. Jul.–Aug. Jun.–Sept. Tromsø 69° 39' 9.4 12.6 11.5 7.7 747 1260 Vardø 70° 22' 6.3 9.3 9.8 6.8 590 983 Bjørnøya 74° 31' 2.0 4.5 5.0 3.0 295 445 Hopen (1946–1965) 76° 30' –0.4 2.0 2.2 0.9 130 157 Hornsund (1970–74) 76° 50' 2.2 5.3 4.8 1.7 315 432 Isfjord Radio 78° 06' 1.8 4.9 4.4 1.3 290 383 Longyearbyen 78° 12' 2.9 6.5 5.3 1.0 365 482 323Engelskjøn et al. 2003: Polar Research 22(2), 317–339 and ecology in Svalbard (Table 2; Appendix 1). Alchemilla glomerulans The species occurs at one locality on Bjørnøya (Engelskjøn 1987: 103–104), which is also its northern limit. The nearest occurrences are on Jan Mayen (Lid 1964: 54) and at Nordkapp (North Cape) (Dahl 1934: 357). In 1983 three individuals (clones) were found in a sheltered gully on the northern coast of Bjørn- øya with the bryophytes Brachythecium refl ex- um, Dichodontium pellucidum, Philonotis tomen- tella, Sanionia uncinata, Syntrichia ruralis and Timmia austriaca and the vascular species Ceras- tium arcticum, C. cerastoides, Festuca rubra ssp. arctica, Oxyria digyna, Ranunculus pygmaeus and Saxifraga cernua. Growing at a slightly dis- turbed site in the vicinity of the Bjørnøya mete- orological station, A. glomerulans might have been introduced accidentally there. However, the species occurs in natural vegetation and may be native to Bjørnøya. See the distribution map in Engelskjøn (1987: 126). Betula nana The species is confi ned to south of Isfjorden (Nathorst 1871: 113; Andersson 1910: 411; Res- voll-Holmsen 1913: 26, 53). At Colesdalen it occurs up to 210 m asl (Alsos, Lund et al. 2002); at Adventdalen, to 140 m asl (Engelskjøn, unpubl. data). Only seven among 39 populations were rated as large. Seed reproduction has not been observed in germination experiments (Misund 1997) or seed bank studies (Alsos et al. 2003; Cooper et al. in press). Betula nana occupies depressions on well- drained, south-facing hillsides. It is associated with Cassiope tetragona and Dryas octopeta- la (Table 14 in Lid 1967) and in places also with Empetrum nigrum ssp. hermaphroditum or Hie- rochloë alpina (Engelskjøn & Spjelkavik 1999). The mushroom, Leccinum rotundifoliae (Fig. 3 in Engelskjøn & Spjelkavik 1999), forms mycor- rhiza with dwarf birch (Gulden & Torkelsen 1996: 190) and appears as an indicator of Low Arctic vegetation. This is a polymorphic species, which seems to comprise several subspecifi c taxa (Hultén & Fries 1986), and probably includes the northern B. tun- drarum Perfi lyev (Tolmachev 1976). De Groot et al. (1997: 253) summarized some taxonomic pro- posals on B. nana. See distribution maps in Engelskjøn (Fig. 5 in 1986) and Elvebakk (Fig. 27 in 1989). See local maps in Hadač (Fig. 10 in 1944), Engelskjøn & Spjelkavik (Fig. 1 in 1999) and Alsos, Lund et al. (2002). Calamagrostis stricta On Bjørnøya this grass is often sterile but may develop culms up to 15 cm tall in late August. On Spitsbergen C. stricta is characteristic of river- banks with culms up to 27 cm in early August. It is rare in the calcareous valley of Sassendalen and absent on the alkaline soils of Eskerdalen (Engel- skjøn, unpubl. data) and Gips dalen (Elven et al. 1990). Twelve large populations were recorded in the Inner Arctic Fjord Zone; otherwise the rather numerous populations are medium-sized (32) or small (21). On Bjørnøya C. stricta associates, for example, with Dupontia psilosantha, Equisetum ar vense, Festuca rubra, Poa pratensis ssp. alpigena and, rarely, with Cardamine pratensis ssp. polemonio- ides, Carex subspathacea, Equisetum vari egatum or Saxifraga cernua. On Spitsbergen the species inhabits mesotrophic to eutrophic mires, associ- ating with Cardamine pratensis ssp. polemonio- ides, Colpodium vahlianum, Dupontia spp. and Eriophorum scheuchzeri. Most Svalbard specimens resemble C. holmii Lange with short, dark panicles (see Hultén 1968: 107, 1973: 465). See distribution maps in Rønning (map 18 in 1972), Elvebakk (Fig. 64 in 1989). See local maps in Hadač (Fig. 36 in 1944) and Engelskjøn (1987: 115). Table 5. Abbreviations of herbaria mentioned in this paper, in accordance with Holmgren et al. (1990). Some of the institu- tional names have been updated. BG Botanical Institute, University of Bergen, Norway C Botanical Museum, University of Copenhagen, Denmark CGE Botany School, University of Cambridge, UK O Botanical Museum, University of Oslo, Norway TRH Dept. of Botany, University of Trondheim (NTNU), Norway TROM Dept. of Botany, Tromsø University Museum, Norway 324 Twenty thermophilous vascular plant species in Svalbard Campanula rotundifolia The species is confi ned to Colesbukta and Coles- dalen, Spitsbergen. It was discovered in 1915 (Asplund 1919: 36) and fl owering started on l3 August that year (specimens in Herbarium O; see Table 5). This is probably the population of C. rotundifolia located on a hill facing Colesbukta, extending over 104 m2. Flowering started on 15 July in the exceptionally warm summer of 1998, in mid-August 1999 and at the end of July 2002. Two additional, small populations were found on the northern side of Colesdalen, succeed- ed towards the interior by a nearly continuous, large population extending over approximately 2600 × 400 m. No germinable seeds or seed bank have been observed (Alsos et al. 2003; Cooper et al. in press). Campanula rotundifolia grows on sandstone lithosol with rock gaps and some turf with meso- trophic species such as Betula nana, Draba dau- rica, Dryas octopetala, Poa glauca and Pole- monium boreale as well as the ubiquitous Bistorta vivipara, Luzula arcuata ssp. confusa and Salix polaris. We noted the scarcity of calciphilous species such as Carex rupestris and Saxifra- ga oppositifolia, which may be explained by the low amounts of calcium carbonate in the bedrock (Major & Nagy 1966). The occurrence of Trise- tum spicatum suggests some protection by rela- tively late-lying snow. Situated 0.4 to 4 km away from the former Colesbukta mining settlement, the occurrences of C. rotundifolia have remained intact up to the present and are still nearly undisturbed by human activity. Flovik (1940) found that Colesbukta plants are diploid (2n = 34). Diploid C. rotundifolia may be given the rank of subspecies or species C. giese- kiana Vest (Böcher 1960; Gadella 1964; Laane 1968; Croff 1978; Shetler 1982). See distribution map in Alsos, Lund et al. (2002). Carex marina ssp. pseudolagopina First found in Sassendalen (by Nathorst in 1882; Herbarium C), but misinterpreted as Carex lagopina (= C. lachenalii ), this taxon was redis- covered on Spitsbergen 80 years later (Schweitzer 1966: 147 and his Fig. 2) and then referred to the synonymic C. amblyorhyncha V. Krecz. in accordance with Böcher (1952; see Halliday & Chater 1969). Carex marina ssp. pseudolagopina is frequent at mires and ponds in Sassendalen and Gips- dalen, 3 - 50 m asl, whereas stations in Dickson Land and at Liefdefjorden are few. Occurrences apparently depend on calcareous substrata with suffi cient moisture. The species Carex marina associates with Cinc- lidium arcticum, Meesia uliginosa, Ortho thecium chryseon, Scorpidium cossonii, Tomen typ num nitens, Cardamine pratensis ssp. polemoni oides, Carex maritima, C. parallela, C. sax atilis, C. sub s pathacea, Equisetum arvense ssp. bore- ale, E. variegatum, Eriophorum triste, Eu trema edwardsii and Juncus triglumis. Böcher (1952: 30) pointed out the slightly halophilous and cal- ciphilous character of C. marina (as C. amblyo- rhyncha) in Greenland. See distribution maps in Böcher (Fig. 12 in 1952), Rønning (map 25 in 1972), Engelskjøn (Fig. 6 in 1986) and Elvebakk (Fig. 67 in 1989). Empetrum nigrum ssp. hermaphroditum Discovered at Grønfjorden (Fries 1869; cf. Elve- bakk & Spjelkavik 1995: 544), Empetrum is fre- quent at Isfjorden (Engelskjøn & Spjelkavik 1999), less so at Bellsund and Van Mijenfjorden (Engelskjøn et al. 1972). It is frequent in Dick- son Land (Högbom 1913; Möller & Thannheiser 1997), inner Kongsfjorden and Liefde fjorden, but is rare in northern Svalbard (Elvebakk & Spjelka- vik 1995; Möller 2000), including Nordaust- landet, at 80.5° N (Brattbakk 1981 cited in Elve- bakk & Spjelkavik 1995). Empetrum ascends to approximately 200 m asl (Hadač 1944: 55). Only nine populations among approximately 80 are considered large. Ripe fruits were recorded in the middle of August at Van Mijenfjorden (Holmboe 1910), on 4 September at Grønfjorden (Wirén 1922), in September at Mimerdalen (Högbom 1913: 153, his Fig. 1) and on 30 July in the warm summer of 1998. Collections from various parts of Spits- bergen bear unripe fruits that could well have reached maturity, but seed reproduction of Empetrum in Svalbard has not been observed in seed bank studies (Alsos et al. 2003; Cooper et al. in press). Empetrum associates with Betula nana south of Isfjorden (Engelskjøn & Spjelkavik 1999). It is acidiphilous (Elvebakk & Spjelkavik 1995; Möller 2000) but was also observed on slightly calcifer- 325Engelskjøn et al. 2003: Polar Research 22(2), 317–339 ous substrata: at Berzeliusdalen with Dryas octo- petala in a carpet of Racomitrium canescens coll. and at lower Reindalen with Cassiope tetragona, Dryas octopetala, Hierochloë alpina and sparse Carex rupestris. In the middle part of Reindalen Empetrum occurs on peaty banks with Sphag- num aongstroemii, Tomentypnum nitens, Cassi- ope tetragona and Salix polaris. Svalbard plants are tetraploid with 2n = 52 (Flovik 1940; Engelskjøn 1979) and monoecious. E. hermaphroditum Hagerup, which is invariably tetraploid and has a northern distribution, was treated as a species (Fredskild 1998) or as a sub- species (Hultén 1968; Böcher et al. 1978). See distribution maps in Elvebakk (Fig. 67 in 1989) and Elvebakk & Spjelkavik (Fig. 2 in 1995). See local maps in Hadač (Fig. 11 in 1944) and Elvebakk & Spjelkavik (Figs. 4, 5 in 1995). Euphrasia frigida This annual plant was discovered at Bockfjorden by Skifte (1960, TROM, see Rønning 1961; Elve- bakk & Spjelkavik 1981). In 1998 E. frigida was found some 150 km farther south, in Colesdalen (Alsos & Lund 1999), and in 2003 a 1 × 2 m patch was found at Ossian Sarsfjellet, Kongs fjorden (TROM). The nearest occurrences are at 71° N on Jan Mayen (Lid 1964: 60) and at Nordkapp (Dahl 1934: 382). Detailed fl ora studies in Colesdalen in 2002 revealed small patches and scattered individu- als of E. frigida within nine 100 × 100 m squares. Three habitats were located north of the settle- ment at Colesbukta, the remaining ones in the south-facing, northern valley slope approxi mately 2 km landward. The largest stand observed was 10 × 70 m, but most were a few square metres (Alsos, Lund et al. 2002). Rønning (1961: 11) reported Euphrasia “in the hollows near the hot springs where the soil tem- perature is high”. At Colesbukta and in Coles- dalen E. frigida grows in Salix polaris commu- nities; in Colesdalen it also grows with Bistorta vivipara, Festuca rubra ssp. arctica and Trisetum spicatum, indicating eutrophic and snow-pro- tected conditions (Fig. 1 in Alsos & Lund 1999). There is no geothermal heat at the Kongsfjorden and Colesbukta sites. See distribution map in Elvebakk (Fig. 11 in 1989). See local map in Alsos, Lund et al. (2002). Hippuris vulgaris This aquatic species is confi ned to shallow pools on Bjørnøya (Engelskjøn 1987). The northern- most station of H. vulgaris is in north Green- land, 82° 13' (map no. 150 in Bay 1992), where- as the stations closest to Bjørnøya are Nord kapp (71° 7' - 8', Dahl 1934) and Karmakula in Novaya Zemlya (72° 24' N, Lynge 1924: 129). Two Bjørn- øya populations are rated as large; elsewhere they are medium-sized or small. Hippuris grows in carpets of Straminergon stramineum or Warnstorfi a tundrae, accompa- nied by Cardamine pratensis ssp. polemonio- ides, Dupontia psilosantha, Equisetum arvense ssp. boreale, Ranunculus hyperboreus and Saxi- fraga rivularis. See the distribution map in Engelskjøn (1987: 127). Juncus castaneus The northernmost representatives are located in north Greenland (Fredskild 1966; Bay 1992). On Spitsbergen J. castaneus is restricted to Gipsdalen, Sassendalen and a few places south of Isfjorden. The drawing in Rønning (Fig. 39b in 1996) is not representative since the selected culm carries only undeveloped (aborted?) cap- sules. The stand at Gipsdalen is very local (Eriksen Norberg, pers. comm. 1999), growing on calcar- eous mud with Scorpidium cossonii. According to Schweitzer (1966: 147), J. castaneus associates with Ranunculus × spetsbergensis at De Geer- dalen. One collection from Longyeardalen con- sisted of 12 culms with half-ripe capsules as of 6 August 1924. To our knowledge this locality has not been seen recently and the plants may have been extirpated. See distribution maps in Rønning (map 11 in 1972) and Elvebakk (Fig. 17 in 1989). Juncus triglumis The species occurs in one place at Recherche- fjorden and more frequently around Isfjorden, Kongsfjorden and Wijdefjorden, inhabiting cal- careous fens from 5 to 70 m asl and associating with Cinclidium sp., Loeskypnum badium, Ortho- thecium chryseon, Paludella squarrosa, Scor- pidium cossonii, S. turgescens, Carex marina ssp. pseudolagopina, C. parallela, C. saxatilis, 326 Twenty thermophilous vascular plant species in Svalbard Eutrema edwardsii and (rarely) Kobresia simpl- iciuscula. The variety albescens Lange has been identi- fi ed from Svalbard. It is regarded as a subspecies by some authors (Elvebakk 1989; Elven 1994; Elven & Elvebakk 1996; Rønning 1996). Others found the varieties of J. triglumis vaguely cir- cumscribed (Sørensen 1933: 159–161; Jørgensen et al. 1958: 47–48). The geographical ranges of ssp. triglumis and ssp. albescens are overlapping according to Hultén & Fries (1986). See distribution maps in Rønning (map 10 in 1972) and Elvebakk (Fig. 18 in 1989). See local map in Hadač (Fig. 36 in 1944). Kobresia simpliciuscula Two stations were reported at the inner branch- es of Isfjorden: Mimerdalen, 2 km from the sea (Lid 1925: 316) and Gipsdalen, 10 - 20 m asl (Engelskjøn 1986) as well as one at Kongs- fjorden, 50 - 130 m asl (Elvebakk 1993). With approximately 10 tufts, the Gipsdalen population is small. The population at Mimerdalen needs investigation, whereas at least one of the popula- tions at Kongsfjorden (Elvebakk 1993) appears as medium-sized (Elvebakk 1993: 251, 253; speci- mens in TROM). At Mimerdalen K. simpliciuscula occurred with Carex parallela and Juncus triglumis (Lid 1925), and the specimens are admixed with Scorpidium cossonii, an indicator of calcareous substratum (Elvebakk 1993: 250; Frisvoll & Elvebakk 1996: 114). At Gipsdalen K. simpliciuscula grew on calcareous mud accompanied by Orthothecium chryseon, Scorpidium cossonii, Bistorta vivi para, Carex marina ssp. pseudolagopina, Carex paral- lela, C. saxatilis, Eutrema edwardsii, Juncus bi glumis, J. triglumis, the ubiquitous Salix polaris and some Draba oxycarpa, Dryas octopetala and Saxifraga hirculus. At Kongsfjorden Kobresia occurred on calcar- eous substrata, as indicated by the admixed Ditri- chum fl exicaule, Hypnum bambergeri, Scorpid- ium turgescens, Tomentypnum nitens, Juncus triglumis and Tofi eldia pusilla. The fens with K. simpliciuscula were “dominated by Carex saxati- lis” (Elvebakk, note on herbarium label). In 2001 and 2002 four small populations of Kobresia simpliciuscula were discovered in Adolf bukta (in Bünsow Land) and at Wijde- fjorden (Ny-Friesland) (Elvebakk, pers. comm. 2002). Details on these localities will be given by Elvebakk et al. (in prep.). See distribution maps in Rønning (map 18 in 1972), Engelskjøn (Fig. 7 in 1986) and Elvebakk (1993). Luzula wahlenbergii The fi rst fi nd in Svalbard was at Bjørndalen (Nat- horst 1883: 37) and subsequent fi nds are all from the siliceous parts of Nordenskiöld Land and Nathorst Land, not above 50 m asl. Only one among 14 populations may be rated as medium- sized; otherwise they are small. Luzula wahlenbergii associates with Onco- phorus wahlenbergii, Sphagnum aongstroemii, S. teres, Straminergon stramineum, Warnstor- fi a sarmentosa, Calamagrostis stricta, Petasites frigidus and Ranunculus pallasii. Tundra mires structured by bryophytes are vulnerable to road- building and terrain wear, for instance at Rein- dalen (Spjelkavik 1991). Although being threat- ened by local road construction, L. wahlenbergii was found within the Longyearbyen settlement as late as 1996 (Brosø, pers. comm. 1997). See distribution maps in Rønning (map 13 in 1972) and Elvebakk (Fig. 30 in 1989). Ranunculus arcticus Ranunculus arcticus is dispersed in Svalbard from Edgeøya (Neilson 1970: 35, as R. pedati- fi dus) and Sørkapp (South Cape) northwards to Krossfjorden. It occupies sunny promontories to 230 m asl at Sassenfjorden (Elvebakk & Hodin 1985, TROM). Neilson (1970) found the species co-dominant at a bird rookery on Edgeøya, but we believe most R. arcticus populations are small. A char- acteristic inhabitant of south-exposed hills with F. rubra ssp. arctica, R. arcticus associates with less common species such as Draba arcti- ca, D. norvegica, Festuca baffi nensis, Polemoni- um boreale, Potentilla hyparctica, P. ×insula- ris, Silene furcata, Taraxacum arcticum and T. brachyceras. Simmons (1906: 101–108) and Lynge (1924: 35 and pl. XXI) discuss the nomenclature of R. affi nis / R. arcticus (see Ericsson 2001: 256). The related R. pedatifi dus Sm., to which the Svalbard plants were referred in earlier treatments, orig- inates from the mid-latitude Altay Mountains (Hadač 1944). See the distribution map in Elvebakk (Fig. 53 in 327Engelskjøn et al. 2003: Polar Research 22(2), 317–339 1989). See local map in Hadač (Fig. 50 in 1944). Ranunculus lapponicus The species extends from Bromelldalen south of Van Mijenfjorden northwards to Wijdefjord en (Nathorst 1883), from 5 m upwards to 130 m asl. A record of R. lapponicus from Edgeøya (Michel- more 1934) is not documented (see Dahl 1937: 25). Among 37 local populations of known size we consider only two as large (Appendix 1). In Adventdalen, Colesdalen and Reindalen Ran- unculus lapponicus occurs in bryophyte com- munities of Aulacomnium palustre, A. turgidum, Onco phorus wahlenbergii, Paludella squar rosa, Sphagnum fi mbriatum, S. squarrosum, S. teres, Sanionia uncinata, Tomentypnum nitens or Warn- storfi a tundrae. It associates with Carex sub- spathacea, Dupontia fi sherii, Equisetum arven- se ssp. boreale, Petasites frigidus (Table 20 in Lid 1967), Ranunculus hyperboreus, R. ×spets- bergensis, R. pallasii and Salix polaris. See distribution maps in Engelskjøn (Fig. 8 in 1986) and Elvebakk (Fig. 52 in 1989). See local map in Hadač (Fig. 53 in 1944). Ranunculus pallasii The species is known from Reindalen, extending 21 km inland and upwards to 70 m asl, and from a few places at Isfjorden (Hadač 1944), reaching 100 m asl at interior Colesdalen (Engelskjøn & Spjelkavik 1999). Records of R. pallasii prior to Nathorst (1883: 21) partly include R. ×spetsber- gensis, and those from Hornsund (Triloff 1944: 292) and Prins Karls Forland (Brown 1908: 315) probably refer to the latter. The rhizomes are immersed during the fi rst half of summer. Characteristic accompanying species are Scapania sp., Sphagnum squarrosum, Warnstorfi a exannulata, W. fl uitans, W. sarmen- tosa, Ranunculus lapponicus, R. ×spetsbergen- sis and Carex subspathacea. On the Reindalsletta plain, 6 August 1985, we observed the drying out of the pools harbouring R. pallasii. See distribution maps in Engelskjøn (Fig. 9 in 1986) and Elvebakk (Fig. 31 in 1989). Ranunculus wilanderi Restricted to a boggy plain inside Kapp Thord- sen at Isfjorden, R. wilanderi was fi rst observed, but not named, by Nathorst (1871). In his origi- nal description Nathorst (1883: 23–24) recorded it “in two places” at Kapp Thordsen, whereas the population was considered as “fairly extensive” by Elven & Elvebakk (1996: 40). Plants apparent- ly numbered not more than 20 in 1996. They were confi ned to runnels between a dolerite cliff with Ranunculus arcticus and a Sphagnum moor with abundant, sterile Rubus chamaemorus. Described as R. affi nis *Wilanderi, this is a member of the R. auricomus complex (Ericsson 2001: 237 and his Fig. 105b), apparently close to var. glabrata Lynge (1924: 35–36, pl. XXII). The latter was described from Novaya Zemlya, and subsequently identifi ed from north-eastern Greenland (Sørensen 1933: 53–54). Var. glabra- ta was ranked as a species R. glabratus by Fager- ström & Kvist (1983). Fig. 4. Salix lanata from Adventdalen, Svalbard. (a) Male individual cultivated at Tromsø Botanic Gardens. Photo: I. G. Alsos (4 May 2002). (b) Twig of cloned offspring cultivated in the phytotron (T 15 °C; 24 hrs daylight), 1998—2002. Note the stipules. Photo: L. Lund (March 2002). (a) (b) 328 Twenty thermophilous vascular plant species in Svalbard Rhodiola rosea The species was fi rst discovered in Svalbard by Keilhau (1831) on his pioneer visit to Bjørn- øya. This island has most of Rhodiola in Sval- bard (Engelskjøn & Schweitzer 1970; Engel- skjøn 1987). Two large populations inhabit the cliffs and promontories of the north-eastern and south-western coasts; otherwise the species is scattered with a few individuals. Occurrences on Prins Karls Forland (Brown 1908: 318), includ- ing Richardlaguna (Rønning, pers. comm. 1985), need further study. Pollen of Rhodiola has been found in droppings of incubating barnacle geese at Lovénøyane islands in Kongsfjorden (Alm & Alsos, unpubl. data 1999), suggesting that the species also may occur in that area. Growing near the coastal brink of Bjørnøya, Rhodiola prefers bedrock of Kulm sandstone and associates with Cochlearia groenlandica, Draba norvegica, Festuca rubra ssp. arctica, F. vivi para and Poa pratensis ssp. alpigena. There is also a Rhodiola–Luzula arcuata community. The broad-leaved, dwarfed Svalbard strain (Fig. 9 in Engelskjøn & Schweitzer 1970) is ref- erable to ssp. arctica (A. Boriss.) Á. & D. Löve (Borissova 1939: 30–31, 171–172). See the distribution map in Elvebakk (Fig. 33 in 1989). See local map in Engelskjøn (1987: 124). Rubus chamaemorus Rubus chamaemorus is restricted to moors near Isfjorden. One stand at Kapp Thordsen meas- ures at least 50 × 50 m and is rated as medium- sized. Due to lack of fl owers in 1996, the local proportion of pistillate / staminate plants is unknown. At Rusanovodden, near Colesbukta, south of the Rusanov hut, there were (in 1998) four stands (with staminate fl owers), measuring 6 × 9 m; 4 × 8 m; 2 × 4 m, and 6 × 7 m, as well as (in 2002) two stands (with pistillate fl owers), meas- uring 5 × 20 m and 20 × 20 m. One stand north of the Rusanov hut, not fl owering in 2002, cov- ered approximately 100 m2. At Colesdalen, near the cemetery south-east of the former mining set- tlement, two patches of staminate plants were found, each 6 × 6 m (Alsos, Lund et al. 2002). Two pistillate stands below Ekmanfjellet were both approximately 10 × 3 m, and a staminate one at the river Hemsil was 9 × 11.5 m in 1998. At Sveasletta, west of Ekmanfjorden, one stand exceeded 10 × 10 m (Wirén 1922; Hauge, pers. comm. 1998). Flowering has been observed at most localities, but seed set is weak because of the prevailing unisexual clones. Ripe fruits were recorded at Sveasletta in the warm season of 1998 (Hauge, pers. comm. 1998). The stands at Kapp Thordsen are on peat, mainly of Sphagnum fi mbriatum. At Rusanovod- den Rubus chamaemorus associates with Aula- comnium turgidum, Dicranum laevidens, Poly- trichum strictum, Sphagnum aongstroemii or S. squarrosum, Betula nana and Luzula arcuata ssp. confusa. At Colesdalen Rubus occurs in meso- trophic bryophyte carpets. The stands west of Ekmanfjorden support Cassiope tetragona and a number of lichen species, e.g. Pilophorus robus- tus, suggesting rather dry conditions. See the distribution map in Elvebakk (Fig. 22 in 1989). See local map in Alsos, Lund et al. (2002). Salix lanata One Spitsbergen occurrence of a disputed Salix sp. is located on the northern brink of Advent- elva, WSW of the Helvetia pingo (Innerhytta). It was discovered by Schweitzer in 1963 (see Hultén 1964; Schweitzer 1966). The juvenile, sparse material was fi rst identifi ed by Hultén as S. glauca L. ssp. callicarpaea (Trautv.) Böcher (see Hultén 1958, 1964). We have studied this occurrence in 1986, 1998 and 2001. Four small clones were permanently established over an area of 10 × 30 m. Only staminate catkins developed in the fi eld and in cultivation at Tromsø Botanic Gardens (Fig. 4a). The Adventdalen Salix grows in bryophyte carpets, mainly of Tomentypnum nitens, together with Alopecurus borealis, Calamagrostis stric- ta, Equisetum arvense ssp. boreale, Poa prat- ensis ssp. alpigena, Bistorta vivipara and Salix polaris. Patches of Dryas octopetala occurred on drier parts of the moist, sloping terrace, which is subjected to river undercutting and may become destroyed in the course of a few decades. Elven & Elvebakk (1996: 41) reported anoth- er medium-sized Salix (as S. arctica) from Ny- Ålesund. That individual was extirpated in 1990 /1991 according to a note on the herbarium label by O. I. Rønning. We have studied materi- al collected in 1974 and (as a dead twig) in 1991 (TRH), and a colour photograph from 1976 (Elve- bakk, pers. comm. 2002), to compare it with the Adventdalen plants. In Elvebakk’s photograph 329Engelskjøn et al. 2003: Polar Research 22(2), 317–339 the sterile Salix sp. is seen with Bistorta vivipara, Salix polaris and Saxifraga oppositifolia. Propagation of a twig transplanted from the Adventdalen Salix in 1998 (Fig. 4b) did not con- fi rm Hultén’s original identifi cation of it as S. glauca ssp. callicarpaea, nor as S. arctica pro- posed by Elven (1994), Elven & Elvebakk (1996), Rønning (1996) and Elven & Karlsson (2000: 141). Its identifi cation as S. lanata was suggest- ed by George Argus, leading salicologist of North America, who has examined photographs and herbarium specimens from Adventdalen (pers. comm. 2002). This is corroborated by leaf mor- phology and venation, well-developed stipules (Fig. 4b), pale yellowish indumentum of short- pedunculate catkins, yellow anthers and glabrous anther fi laments (Fig. 4a). Carrying obovate, reticulate leaves, the sparse material from Ny-Ålesund is also referable to Salix lanata. Both populations resemble low-growing strains of ssp. richardsonii (Hook.) A. Skvortzov, a view advanced by Elven (pers. comm. 2002). Further investigation is needed to assess the local dis- tribution and phytogeographical connections of Salix lanata in Spitsbergen. Vaccinium uliginosum The species was discovered in 1908 at Mimer- dalen (Lid 1925) and subsequently collected at what was then known as Coles Bay by G. Holm- sen in 1912. The Vaccinium habitat at Krekling- passet, north of Adventdalen, approximately 200 m asl, was exposed to natural erosion in 1981 (J. Nilsen, pers. comm. 1999). The species was not seen there in 1998 and may have been locally extirpated. The Colesdalen population is medium-sized, covering more than half of an area of 1360 m2 (consisting of one genotype), with two satellites (a closely related genotype) extending over 3.2 m2 and 16 m2, located 32 m and 40 m uphill, respec- tively (Alsos, Brochman et al. 2002). The Coles- dalen habitat is a south-facing slope with pros- trate Vaccinium mixed with Cassiope tetragona and Dryas octopetala. At Rusanovodden, 40 m asl, another medium-sized population, not fl ow- ering, was discovered in 2002. It occurred with Betula nana and Empetrum nigrum ssp. herm- aphroditum (Alsos, Lund et al. 2002). No germinable seeds or seed bank have been found in the Colesdalen population, the only place where fl owers or fruits have been observed in Svalbard (Alsos et al. 2003; Cooper et al. in press). One Vaccinium stand at Mimerdalen extend- ing over a few square metres, probably on the hill Estheriahaugen (O. A. Høeg, 1928, TRH), was accompanied by Dryas octopetala, Carex rupes- tris, Bistorta vivipara, Luzula arcuata ssp. con- fusa, Salix polaris, Dicranum laevidens, Tomen- typnum nitens and several fruticose lichens, e.g. Thamnolia vermicularis (Möller & Thannheis- er 1997). Idodalen harbours stands of two partly overlap- ping V. uliginosum genotypes measuring 120 m2 and 60 m2, only 3 m apart (Alsos, Brochman et al. 2002). Co-dominant were Cassiope tetragona, Saxifraga oppositifolia and Tomentypnum nitens associating with some restricted, calciphilous species, e.g. Tofi eldia pusilla. Material from Colesbukta was found to be di ploid with 2n = 24 (Flovik 1940). All the Sval- bard populations are referred to the circumpo- lar ssp. microphyllum (Lge.) Tolm. (Alsos et al. 2003). See the distribution map in Elvebakk (Fig. 32 in 1989). See local map in Alsos, Lund et al. (2002.) Discussion The Spitsbergen ranges of the thermophilous spe- cies broadly coincide with the Inner Arctic Fjord Zone (Elvebakk 1989), where the Longyearbyen meteorological station enjoys the highest summer warmth, 365 degree-days for July–August. How- ever, we consider this local climate as marginal for the following 12 target species which require more than 400 degree-days for July–August (data from Engelskjøn 1994): Alchemilla glomeru- lans, Betula nana, Calamagrostis stricta, Cam- panula rotundifolia, Euphrasia frigida, Hippuris vulgaris, Juncus castaneus, J. triglumis, Ranun- culus lapponicus, Rubus chamaemorus, Salix lanata and Vaccinium uliginosum. Lack of viable seeds or seed bank in three of these species, i.e. B. nana, C. rotundifolia and V. uliginosum, suggests that thermal requirements for seed production have not been met during recent decades (Misund 1997; Alsos et al. 2003). Among the 20 thermophilous species treated here, 13 attain their northernmost limits in Sval- bard. The remaining seven have their polar limits 330 Twenty thermophilous vascular plant species in Svalbard in northern Greenland, from 81° 55' to 83° N (Fredskild 1966; Bay 1992, 1997). A farthest north station of “Empetrum nigrum” (Edlund & Alt 1989) indicates that Ellesmere Island also possesses world northern limits of fl ora. Other Boreal or Arctic species have been recorded in the fossil or subfossil state north of their present ranges. Instances are Angelica cf. archangelica (Bjørnøya, Wohlfahrt et al. 1995); Armeria scabra (Edgeøya, Bennike & Hedenäs 1995); Parnassia palustris (Spitsbergen, van der Knaap 1988); Saussurea alpina (Spitsbergen, van der Knaap 1988) and Selaginella selaginoides (Jan Mayen, van der Knaap 1987). Possible relict occurrences of these or other warmth-demanding species should be searched for in the Inner Arctic Fjord Zone of Svalbard. Eutrophic, mesotrophic and oligotrophic spe- cies are represented in the group of thermophi- lous species. There is no over-representation of species with particular edaphical demands (see Elvebakk 1982). The following three species have most popu- lations: Calamagrostis stricta (108), Empetrum nigrum ssp. hermaphroditum (approximately 80), and Ranunculus lapponicus (70). In these cases, medium-sized or large populations prevail and the species may be locally copious. Accordingly, they were rated as at lower risk in Svalbard. Less frequent, with 22 to 39 populations, are Betula nana, Hippuris vulgaris (found only on Bjørnøya), Juncus triglumis, Rhodiola rosea (mainly on Bjørnøya) and Ranunculus arcticus. They are rated as vulnerable or at lower risk. Species with 1 - 16 populations are Alchemil- la glomerulans (only on Bjørnøya), Campanula rotundifolia, Carex marina ssp. pseudolagopina, Euphrasia frigida, Juncus castaneus, Kobresia sim pliciuscula, Luzula wahlenbergii, Ranuncu- lus pallasii, R. wilanderi, Rubus chamaemorus, Salix lanata and Vaccinium uliginosum. Depend- ing on local conditions, they are rated as vulnera- ble, endangered or critically endangered. The latter category—critically endangered at the regional level—comprises Alchemil- la glomerulans (confi ned to Bjørnøya), Ranun- culus wilanderi (confi ned to Kapp Thordsen), Salix lanata (extirpated at Ny-Ålesund, persist- ing at Adventdalen) and Vaccinium uliginosum (critically endangered at Colesdalen because of a mining scheme). Among the target species, Betula nana, Cam- panula rotundifolia and Salix lanata are entire- ly unprotected by the present area-based conser- vation plan (Fig. 2). One Svalbard population of Salix lanata has probably become extirpated, the remaining one, consisting of only male plants, is threatened by natural erosion. Ex situ conserva- tion is now being implemented at the Phytotron of the University of Tromsø and Tromsø Botan- ic Gardens. There are strong Norwegian and Russian min- ing interests within several of the proposed nature reserves in Svalbard. As a result, the Nor- wegian conservation authorities have signalled that mining and conservation interests should be combined to some extent within the protected areas (Miljøverndepartementet 2003). The pro- posed protected area at Colesdalen (Governor of Svalbard 1999; Alsos, Lund et al. 2002) has been disputed due to Russian mining interests and has so far not been protected by the Norwegian gov- ernment (Miljøverndepartementet 2003), con- trary to botanical recommendations. This area includes populations of Betula nana, Campanu- la rotundifolia, Empetrum nigrum ssp. hermaph- roditum, Euphrasia frigida, Ranunculus lapponi- cus and Vaccinium uliginosum. The climate-correlated, northward decline of vascular plant species (Murray 1997) shows a local anomaly in the Inner Arctic Fjord Zone of Spitsbergen, especially in Dickson Land, Sabine Land and Nordenskiöld Land, which altogeth- er harbour more than 15 thermophilous species (Fig. 3). Due to its small and fragmented popula- tions, this phytogeographical element needs fur- ther investigation as to its Holocene past. It is clearly in need of conservation. Acknowledgements.—We thank Liv Borgen, Arne Peder- sen, Hans-Joachim Schweitzer and associates for participat- ing in fi eldwork in 1967, 1970 or both; Sigbjørn Dunfjeld and Ola Skifte in 1983; Christian Brochmann, Arve Elve- bakk, Reidar Elven, Lars Hodin and Sigmund Spjelkavik in 1985; Jan Thomas Schwenke, Sigmund Spjelkavik and Anne Steilnes in 1986; Knut Engelskjøn and Anne Steilnes in 1987; Mari Aasen in 1998, Bjørn Erik Sandbakk in 1998, 1999, 2002 and 2003, members of the North Norwegian Botanical Asso- ciation in 2002 and Kjell Tore Hansen in 2003. Geir Mathias- sen provided notes on Betula nana and mushrooms at Advent- dalen in 1986; information on Juncus castaneus was provided by May-Britt Eriksen Norberg; on Luzula wahlenbergii by Birgit Brosø, on Rubus chamaemorus by Ivar Hauge and Jarle Nilsen and on Vaccinium uliginosum by Jarle Nilsen. We thank George Argus, Merrickville, Ontario, and Reidar Elven, Oslo, for comments on the Adventdalen Salix lanata, and Arve Elvebakk for providing an in situ photograph of the presently extirpated S. lanata at Ny-Ålesund. We are indebt- 331Engelskjøn et al. 2003: Polar Research 22(2), 317–339 ed to Ernst Høgtun for preparing the maps. The present study was fi nanced by Tromsø Museum, the Norwegian Polar Insti- tute, the Norwegian National Committee for Polar Research (7/221.34-10/98) and the Roald Amundsen Centre for Arctic Research (A 21/98). Arve Elvebakk shared some unpublished plant fi nds and provided valuable comments on the manu- script, as did Torbjørn Alm. Elisabeth Cooper reviewed the language. We thank the anonymous reviewers for construc- tive suggestions. References Alsos, I. G. 2000: Utbredelse av sjeldne karplanter sett i forhold til “Plan for nye verneområder på Svalbard”. (Dis- tribution of rare vascular plants in relation to the “Plan for new protected areas in Svalbard.”) Polarfl okken 23, 193– 201. Alsos, I. G. 2003: Conservation biology of the most ther- mophilous plant species in the Arctic. Genetic variation, recruitment and phytogeography in a changing climate. Dr. Scient. thesis, University of Tromsø. Alsos, I. G., Brochmann, C. & Engelskjøn, T. 2002: Con- servation genetics and population history of Betula nana, Vaccinium uliginosum, and Campanula rotundifolia in the Arctic archipelago of Svalbard. Arct. Antarct. Alp. Res. 34, 408–418. Alsos, I. G. & Lund, L. 1999: Fjelløyentrøst Euphrasia frigi- da funnet i Colesdalen, Svalbard. (Euphrasia frigida found in Colesdalen, Svalbard.) Blyttia 57, 36. Alsos, I. G., Lund, L., Sandbakk, B. E. & Westergaard, K. 2002: Floraen i Colesdalen. Kartlegging av det planlagte verneområde. (The fl ora of Colesdalen. Mapping of the planned protected area.) Tromsø: Botany Unit, Tromsø Museum, University of Tromsø. Alsos, I. G., Spjelkavik, S. & Engelskjøn, T. 2003: Seed bank size and composition of Betula nana, Vaccinium uligino- sum, and Campanula rotundifolia in Svalbard and northern Norway. Can. J. Bot. 81, 220–231. Andersson, G. 1910: Die jetzige und fossile Quartär fl ora Spitzbergens als Zeugnis von Klimaänderungen. (The present and fossil Quaternary fl ora of Spitsbergen as evi- dence for climatic change.) In: II. internationaler Geologen- kongress. Die Veränderungen des Klimas seit dem Maxi- mum der letzten Eiszeit. Pp. 409–417. Stockholm: General- stabens Litografi ska Anstalt. Andersson, G. & Hesselman, H. 1900: Bidrag till kännedo- men om Spetsbergens och Beeren Eilands kärlväxtfl ora grundade på iakttagelser under 1898 års svenska polarex- pedition. (Contribution to the vascular fl ora of Spitsbergen and Bjørnøya based on observations during the Swedish polar expedition 1898.) Bihang Kungliga Svenska Veten- skaps-Akademiens Handlingar 26, III, 1–88. Asplund, E. 1919: Beiträge zur kenntnis der fl ora des Eis- fjordgebietes. (Contribution to the fl ora of the Isfjorden area.) Ark. Bot. 15, 1–40. Aune, B. 1993: Temperaturnormaler, normalperiode 1961– 1990. (Temperature normals, normal period 1961–1990.) Klima 93. Oslo: Norwegian Meteorological Institute. Baranowski, S. 1975: The climate of west Spitsbergen in the light of material obtained from Isfjord Radio and Horn- sund. Acta Univ. Wratislav. 251, 21–34. Bay, C. 1992: A phytogeographical study of vascular plants of northern Greenland—north of 74° northern latitude. Medd. Grønl. Biosci. 36. Bay, C. 1997: Floristic and ecological characterization of the polar desert zone of Greenland. J. Veg. Sci. 8, 685–696. Bennike, O. & Hedenäs, L. 1995: Early Holocene land fl oras and faunas from Edgeøya, eastern Svalbard. Polar Res. 14, 205–214. Birks, H. H. 1991: Holocene vegetational history and climat- ic changes in west Spitsbergen—plant macrofossils from Skardtjørna, an Arctic lake. The Holocene 1, 209–218. Böcher, T. W. 1952: A study of the circumpolar Carex Heleon- astes–amblyorhyncha complex. Acta Arct. 5, 1–32. Böcher, T. W. 1960: Experimental and cytological studies on plant species V. The Campanula rotundifolia complex. Biol. Skr. Dan. Vidensk. Selsk. 11, 1–69. Böcher, T. W., Holmen, K., Fredskild, B. & Jakobsen, K. 1978: Grønlands fl ora. 3. reviderede udgave. (The fl ora of Greenland. 3rd revised edition.) Copenhagen: P. Haase & Søn. Borissova, A. G. 1939: Crassulaceae DC. Flora SSSR 9, 8– 134, 471–486. Cooper, E. J., Alsos, I. G., Hagen, D., Smith, F. M., Coulson, S. & Hodkinson, I. in press: Plant recruitment in the High Arctic: seed bank and seedling emergence in the fi eld on Svalbard. J. Veg. Sci. Croff, B. E. 1978: Campanula rotundifoliakomplekset i Norge. En cytologisk og morfologisk analyse. (The Cam- panula rotundifolia complex in Norway. A cytological and morphological analysis.) Cand. real. thesis, Univer- sity of Oslo. Dahl, E. 1937: On the vascular plants of eastern Svalbard. Skrifter om Svalbard og Ishavet 75. Oslo: Norway’s Sval- bard and Arctic Ocean Research Survey (predecessor of the Norwegian Polar Institute). Dahl, E. & Hadač, E. 1946: Et bidrag til Spitsbergens fl ora. (A contribution to the fl ora of Spitsbergen.) Meddelelser 63. Oslo: Norway’s Svalbard and Arctic Ocean Research Survey (predecessor of the Norwegian Polar Institute). Dahl, O. 1934: Floraen i Finnmark fylke. (The fl ora of Finn- mark county.) Nyt Magazin for Naturvidenskaberne 169. De Groot, W. J., Thomas, P. A. & Wein, R. W. 1997: Betula nana L. and Betula glandulosa Michx. J. Ecol. 85, 241– 264. Dubiel, E. 1990: Vascular plants of the NW part of Sørkapp Land (Spitsbergen). Distribution and habitats. Zesz. Nauk. Univ. Jagiell. Prace Bot. 21, 7–33. Edlund, S. A. & Alt, B. T. 1989: Regional congruence of vege- tation and summer climate patterns in the Queen Elizabeth Islands, Northwest Territories, Canada. Arctic 42, 3–23. Elvebakk, A. 1982: Geological preferences among Svalbard plants. Inter-Nord 16, 11–31. Elvebakk, A. 1985: Higher phytosociological syntaxa on Sval- bard and their use in subdivision of the Arctic. Nordic J. Bot. 5, 273–284. Elvebakk, A. 1989: Biogeographical zones of Svalbard and adjacent areas based on botanical criteria. Dr. scient. thesis, University of Tromsø. Elvebakk, A. 1993: Myrtust (Kobresia simpliciuscula) på Sval bard. (Kobresia simpliciuscula in Svalbard.) Polarfl ok- ken 17, 249–254. Elvebakk, A., Elven, R., Spjelkavik, S., Thannheiser, D. & Schweitzer, H.-J. 1994. Botrychium boreale and Puccinel- lia angustata ssp. palibinii new to Svalbard. Polarfl okken 18, 133–140. Elvebakk, A., Engelskjøn, T. & Hodin, L. 1987: Vegetasjons- 332 Twenty thermophilous vascular plant species in Svalbard skader i Berzeliusdalen. (Vegetation damage at Ber zel ius- dalen.) In P. Prestrud & N. A. Øritsland (eds.): Miljø under- søkelser i tilknytning til seismisk virksomhet på Svalbard 1986. Nor. Polarinst. Rapp.ser. 34, 161–194. Elvebakk, A. & Hertel, H. 1996: Lichens. In A. Elvebakk & P. Prestrud (eds.): A catalogue of Svalbard plants, fungi, algae, and cyanobacteria. Nor. Polarinst. Skr. 198, 271– 359. Elvebakk, A. & Spjelkavik, S. 1981: Botanisering blant varme kjelder og vulkanar på Nord-Svalbard. (Botaniz- ing among hot springs and volcanos in northern Svalbard.) Polarfl okken 5, 104–113. Elvebakk, A. & Spjelkavik, S. 1995: The ecology and distri- bution of Empetrum nigrum ssp. hermaphroditum on Sval- bard and Jan Mayen. Nord. J. Bot. 15, 541–552. Elven, R. 1994 (ed.): Johannes Lid, Dagny Tande Lid: Norsk fl ora. (Johannes Lid, Dagny Tande Lid: Norwegian fl ora.) Oslo: Det Norske Samlaget. Elven, R. & Elvebakk, A. 1996: Vascular plants. In A. Elve- bakk & P. Prestrud (eds.): A catalogue of Svalbard plants, fungi, algae, and cyanobacteria. Nor. Polarinst. Skr. 198, 9–55. Elven, R. & Elvebakk, A. 2002: Sibirstarr Carex bige lowii ssp. arctisibirica på Svalbard og noe om stivstarr–kom- plekset C. bigelowii coll. (Carex bigelowii ssp. arctisibiri- ca in Svalbard and comments on the C. bigelowii complex.) Blyttia 60, 50–58. Elven, R., Eriksen, M.-B., Elvebakk, A., Johansen, B. & Engelskjøn, T. 1990: Gipsdalen, central Svalbard; fl ora, veg etation and botanical values. In B. Brekke & R. Hanson (eds.): Environmental atlas, Gipsdalen, Svalbard. II. Nor. Polarinst. Rapp.ser. 61, 27–66. Elven, R. & Karlsson, T. 2000: Salicaceae: Salix arctica Pall. In B. Jonsell (ed.): Flora Nordica 1. Lycopodiaceae—Poly- podiaceae. Pp. 141–142. Stockholm: Bergius Foundation. Engelskjøn, T. 1979: Chromosome numbers in vascular plants from Norway, including Svalbard. Opera Bot. 52, 1–38. Engelskjøn, T. 1986: Zonality of climate and plant distribu- tion in some Arctic and Antarctic regions. Nor. Polarinst. Rapp.ser. 30. Engelskjøn, T. 1987: Eco-geographical relations of the Bjørn- øya vascular fl ora, Svalbard. Polar Res. 5, 79–127. Engelskjøn, T. 1994: High- and mid-alpine vegetation in north Scandinavia. Ecology and thermal relations. Tromu- ra, Naturvitenskap 74. Tromsø: Tromsø Museum, Unives- rity of Tromsø. Engelskjøn, T., Kramer, K. & Schweitzer, H.-J. 1972: Zur fl ora des Van Mijenfjordengebietes und Hopens. (Con- tribution to the fl ora of the Van Mijenfjorden district and Hopen.) Nor. Polarinst. Årb. 1970, 191–198. Engelskjøn, T. & Schweitzer, H.-J. 1970: Studies on the fl ora of Bear Island (Bjørnøya). I. Vascular plants. Astarte 3, 1– 36. Engelskjøn, T. & Spjelkavik, S. 1999: Vegetasjon med dverg- bjørk (Betula nana L.) ved Colesdalen, Svalbard. (Vegeta- tion supporting dwarf birch (Betula nana L.) at Colesdalen, Svalbard.) Polarfl okken 23, 21–28. Ericsson, S. 2001: Ranunculaceae: Ranunculus auricomus. In B. Jonsell (ed.): Flora Nordica 2. Chenopodiaceae—Fum- ariaceae. Pp. 237–255. Stockholm: Bergius Foundation. Fagerström, L. & Kvist, G. 1983: Vier neue arktische und sub- arktische Ranunculus auricomus-Sippen. Ann. Bot. Fenn. 20, 237–243. Flovik, K. 1940: Chromosome numbers and polyploidy with- in the fl ora of Spitzbergen. Hereditas 26, 430–440. Fredskild, B. 1966: Contribution to the fl ora of Peary Land, north Greenland. Medd. Grønl. 178(2). Fredskild, B. 1998: The vegetation types of northeast Green- land. Medd. Grønl. Biosci. 49. Fries, T. M. 1869: Tillägg till Spetsbergens fanerogam-fl ora. (Addition to the phanerogamic fl ora of Spitsbergen.) Öfver- sigt Kungliga Vetenskaps-Akademiens Förhandlingar 26, 121–144. Frisvoll, A. A. & Elvebakk, A. 1996: Bryophytes. In A. Elve- bakk & P. Prestrud (eds.): A catalogue of Svalbard plants, fungi, algae, and cyanobacteria. Nor. Polarinst. Skr. 198, 57–172. Gadella, W. 1964: Cytotaxonomical studies in the genus Cam- panula. Wentia 11. Governor of Svalbard 1999: Melding om konsekvensutredn- ing. Plan for nye verneområder på Svalbard. (Consequence assessment report. Plan for new protected areas in Sval- bard.) Longyearbyen: Offi ce of the Governor of Svalbard. Gulden, G. & Torkelsen, A. E. 1996: Fungi I. Basidiomy cota: Agaricales, Gasteromycetales, Aphyllophorales, Exobasid- iales, Dacrymycetales and Tremellales. In A. Elvebakk & P. Prestrud (eds.): A catalogue of Svalbard plants, fungi, algae, and cyanobacteria. Nor. Polarinst. Skr. 198, 173– 206. Hadač, E. 1944: Die Gefässpfl anzen des “Sassengebietes” Vestspitsbergen. (The vascular plants of the “Sassen Quar- ter”, west Spitsbergen.) Skrifter om Svalbard og Ishavet 87. Oslo: Norway’s Svalbard and Arctic Ocean Research Survey (predecessor of the Norwegian Polar Institute). Halliday, G. & Chater, A. O. 1969: Carex marina Dewey, an earlier name for C. amblyorhyncha Krecz. Feddes Repert. 80, 103–106. Hansen, J. R., Hansson, R. & Norris, S. 1996: The state of the European Arctic environment. Environmental Monograph 3. Oslo: European Environment Agency. Hjelmstad, R. 1981: Flora- og vegetasjonsundersøkelser på Barentsøya. (Investigations of fl ora and vegetation on Barentsøya.) MAB i Norge—Svalbardprosjektet. Rapp. 8. Oslo. Hofmann, W. & Thannheiser, D. 1972: Floristische Neufun- de von Kross- und Kongsfjord, Spitzbergen. (New fl oris- tic discoveries at Krossfjord and Kongsfjord, Spitsbergen.) Polarforschung 42, 122–124. Högbom, B. 1913: Om Spetsbergens Mytilustid. (On the Mytilus epoch of Spitsbergen.) Geol. Fören. För handl. 35, 151–155. Holmboe, J. 1910: Moden krækling fra Spitsbergen. (Ripe Empetrum from Spitsbergen.) Naturen 34, 380–381. Holmen, K. 1957: The vascular plants of Peary Land, north Greenland. Medd. Grønl. 124. Holmgren, P. K., Holmgren, N. H. & Barnett, L. C. 1990: Index herbariorum. Part I: the herbaria of the world. New York: New York Botanical Garden. Hultén, E. 1958: The amphi-Atlantic plants and their phyto- geographical connections. Kungliga Svenska Vetenskaps- Akademiens Handlingar. Ser. 4(7). Hultén, E. 1964: Salix glauca subsp. callicarpaea in Spits- bergen. Sven. Bot. Tidskr. 58, 350. Hultén, E. 1968: Flora of Alaska and neighboring territories. Stanford: Stanford University Press. Hultén, E. 1973: Supplement to fl ora of Alaska and neighbor- ing territories. A study in the fl ora of Alaska and the trans- beringian connection. Bot. Not. 126, 459–512. Hultén, E. & Fries, M. 1986: Atlas of north European vascu- lar plants north of the Tropic of Cancer. Königstein: Koeltz 333Engelskjøn et al. 2003: Polar Research 22(2), 317–339 Scientifi c Books. IUCN (World Conservation Union) 2001: IUCN Red List cat- egories and criteria version 3.1. On the internet at www. redlist.org/info/categories_criteria.html. Jørgensen, C. A., Sørensen, T. & Westergaard, M. 1958: The fl owering plants of Greenland. A taxonomical and cytolog- ical study. Biologiske Skrifter Kongelige Danske Vidensk- abers Selskab 9. Keilhau, B. M. 1831: Reise i Öst- og Vest-Finmarken samt til Beeren-Eiland i aarene 1827 og 1828. (Travel to eastern and western Finnmark and to Bjørnøya during the years 1827 and 1828.) Christiania (Oslo): Cappelen. Kuc, M. & Dubiel, E. 1995: The vascular plants of the Horn- sund area (SW Spitsbergen). Fragm. Flor. Geobot. 40, 797–824. Laane, M. M. 1968: Cyto-ecological studies in Norwegian Cam panula-species. Bot. Tidsskr. 63, 319–334. Lid, J. 1925: Four new phanerogams from Svalbard (Spits berg- en). Nyt Magazin for Naturvidenskaberne 63, 315–316. Lid, J. 1962: Stutt-arve funnen på Svalbard. (Sagina caespito- sa found in Svalbard.) Blyttia 20, 100–101. Lid, J. 1964: The fl ora of Jan Mayen. Nor. Polarinst. Skr. 130. Lid, J. 1967: Synedria of twenty vascular plants from Sval- bard . Bot. Jahrb. 86, 481–493. Lynge, B. 1924: Vascular plants from Novaya Zemlya. Rep- ort of the scientifi c results of the Norwegian expedition to Novaya Zemlya 1921. No. 13. Kristiania (Oslo): Videnskaps- selskapet. Major, H. & Nagy, J. 1966: Geology of the Adventdalen area. With geological map, Svalbard C9G, 1:100 000. Nor. Polar- inst. Skr. 138. Malmgren, A. J. 1862: Öfversigt af Spetsbergens fanerogam- fl ora. (Survey of the phanerogamic fl ora of Spitsbergen.) Öfversigt Kungliga Vetenskaps-Akademiens Förhandling- ar 1862, 229–268. Michelmore, A. P. G. 1934: Botany of the Cambridge expe- dition to Edge Island, S.E. Spitsbergen, in 1927. J. Ecol. 22, 156–176. Miljøverndepartementet 2003: Mest omfattende vern på 30 år sikrer Svalbards unike natur. (The most comprehensive protection in 30 years safeguards the unique nature of Sval- bard.) Press release 26/09/03. Oslo: Ministry of the Envi- ronment. Available on the internet at http://odin.dep.no/ md /norsk /tema /svalba rd /a rk iv/ 022021- 070159/i ndex- dok000-b-n-a.html. Misund, S. 1997: Germination and growth in Betula nana L. from Spitsbergen and Tromsø. Cand. scient. thesis, Univer- sity of Tromsø. Möller, I. 2000: Pfl anzensoziologische und vegetationsökolo- gische Studien in Nordwestspitzbergen. (Phytosociological and vegetation ecological studies in northwestern Spits- bergen.) Mitt. Geogr. Ges. Hamb. 90. Möller, I. & Thannheiser, D. 1997: Eine V\vegetationsoase im unteren Mimerdalen am Billefjord, Zentral-Spitzber- gen. (A vegetational oasis at lower Mimerdalen, Billefjord, central Spitsbergen.) Polarforschung 65, 65–70. Murray, D. F. 1997: Regional and local vascular plant diver- sity in the Arctic. Opera Bot. 132, 9–18. Nathorst, A. G. 1871: Om vegetationen på Spetsbergens vest kust. (On the vegetation on the western coast of Spits- bergen.) Bot. Not. 1871, 105–117. Nathorst, A. G. 1883: Nya bidrag till kännedomen om Spets- bergens kärlväxter, och dess växtgeografi ska förhålland- en. (New contributions to the knowledge of the vascular plants of Spitsbergen, and their phytogeographical rela- tions.) Kungliga Svenska Vetenskaps-Akademiens Han- dlingar 20. Neilson, A. H. 1968: Vascular plants from the northern part of Nordaustlandet, Svalbard. Nor. Polarinst. Skr. 143. Neilson, A. H. 1970: Vascular plants of Edgeøya, Svalbard. Nor. Polarinst. Skr. 150. Resvoll-Holmsen, H. 1913: Observations botaniques. Explo- ration de nord-ouest de Spitsberg entreprise sous les aus- pices de S.A. le Prince de Monaco par la mission Isach- sen. (Botanical observations. Exploration of northwestern Spitsbergen performed by the Isachsen expedition, spon- sored by H. E. the Prince of Monaco.) Résultats Campagne Scientifi que Prince Albert I, 44. Imprimerie de Monaco. Rønning, O. I. 1961: Some new contributions to the fl ora of Svalbard. Norsk Polarinst. Skr. 124. Rønning, O. I. 1972: The distribution of the vascular cryp- togams and monocotyledons in Svalbard. Det Kongelige Norske Videnskabers Selskabs Skrifter 24. Rønning, O. I. 1996: Svalbards fl ora. (Flora of Svalbard.) Polarhåndbok 9. Oslo: Norwegian Polar Institute. Rudmose Brown, R. N. 1908: The fl ora of Prince Charles Fore- land, Spitsbergen. Bot. Soc. Edinb. Trans. 23, 313–320. Schweitzer, H.-J. 1966: Beiträge zur Flora Svalbards. (Con- tributions to the fl ora of Svalbard.) Nor. Polarinst. Årb. 1964, 139–148. Shetler, S. G. 1982: Variation and evolution of the nearctic hare bells (Campanula subsect. Heterophylla). Phanero- gamarum Monographiae 11. Vaduz, Liechtenstein: J. Cramer. Simmons, H. G. 1906: The vascular plants in the fl ora of Ellesmereland. Results of the Norwegian Arctic expe- ditions in the “Fram” 1898–1902, 2. Kristiania (Oslo): Videnskabs-Selskapet. Sørensen, T. 1933: The vascular plants of East Greenland from 71°00' to 73°30' n. lat. Medd. Grønl. 101. Spjelkavik, S. 1991: Vegetasjonsundersøkelser langs fores- låtte veitraséer mellom Longyearbyen og Svea. Investiga- tion of vegetation along proposed roads between Longyear- byen and Svea. Nor. Polarinst. Medd. 117, 11–26. Steffensen, E. 1982: The climate at Norwegian Arctic sta- tions. Klima 5. Oslo: Norwegian Meteorological Institute. Stortinget 2000: Reg jeringens miljøvernpolitikk og rikets miljøtilstand. Stortingsmelding nr. 8, 1999–2000. (Envi- ronmental policies of the Government and the environ- mental state of the Kingdom.) Oslo: Ministry of the Envi- ronment. Available on the internet at http://odin.dep.no/ md/norsk/publ/stmeld/022005-040006/index-dok000-b- n-a.html. Summerhayes, V. S. & Elton, C. S. 1928: Further contribu- tions to the ecology of Spitsbergen. J. Ecol. 16, 193–268. Sunding, P. 1966: Plantefunn fra Vestspitsbergen sommer- en 1964. (Plant fi nds on Spitsbergen, the summer of 1964.) Nor. Polarinst. Årb. 1964, 149–154. Thannheiser, D. 1972: Vegetationskartierungen auf der Ger- maniahalvøya. Vegetation mapping on the Germania- halvøya. Stuttg. Geogr. Stud. 117, 141–160. Theisen, F. & Brude, O. W. 1998: Evaluering av områdever- net på Svalbard. Representativitet og behov for ytterligere vern. (Assessment of the areal protection in Svalbard. Representativity and needs of extended protection.) Nor. Polarinst. Medd. 153. Tolmachev, A. I. 1976: Flora severo-vostoka evropeiskoi časti SSSR II. Cyperaceae–Caryophyllaceae. (Flora of the north-western European parts of the USSR II. Cyperace- 334 Twenty thermophilous vascular plant species in Svalbard ae–Caryophyllaceae.) Leningrad: Nauka. Tolmachev, A. I., Packer, J. G. & Griffi ths, G. C. D. (eds.) 1996: The fl ora of the Russian Arctic 3: Salicaceae to Ranunculaceae. Edmonton: University of Alberta Press. Triloff, E. G. 1944: Verbreitung und ökologie der gefäss- pfl anzen im gebiete des Hornsundes: ein beitrag zur veg- etationskunde Spitzbergens. (Distribution and ecology of the vascular plants of the Hornsund area: a contribution to the knowledge of the vegetation of Spitsbergen.) Bot. Jahrb. 37, 259–360. Turnbull, R. 1900: Contributions to the fl ora of Spitsbergen, especially of Red Bay, from the Collections of W. S. Bruce, F.R.S.G.S., naturalist to the Prince of Monaco’s expedi- tions of 1898 and 1899. Transactions and Proceedings of the Botanical Society of Edinburgh 1900, 352–357. van der Knaap, W. O. 1987: Five short pollen diagrams of soils from Jan Mayen, Norway: a testimony of a dynamic landscape. Polar Res. 5, 193–206. van der Knaap, W. O. 1988: A pollen diagram from Brøgger- halvøya, Spitsbergen: changes in vegetation and environ- ment from ca. 4400 to ca. 800 BP. Arct. Alp. Res. 20, 106– 116. van der Knaap, W. O. 1989: Past vegetation and reindeer on Edgeøya (Spitsbergen) between c. 7900 and c. 3000 BP, studied by means of peat layers and reindeer faecal pellets. J. Biogeogr. 16, 379–394. Wirén, E. 1922: Iakttagelser under några botaniska exkur- sioner på Spetsbergen. (Observations during some botani- cal excursions on Spitsbergen.) Sven. Bot. Tidskr. 16, 363– 370. Wohlfahrt, B., Lemdahl, G., Olsson, S., Persson, T., Snow- ball, I., Ising, J. & Jones, V. 1995: Early Holocene environ- ment on Bjørnøya (Svalbard) inferred from multidiscipli- nary lake sediment studies. Polar Res. 14, 253–275. Species Population sizes Part of Svalbard Location Source, herbaria with voucher specimens L M S Nd ∑ Alchemilla glomerulans Bjørnøya SE of Herwighamna TE 1983, TROM; TE (1987) 1 1 Total 1 1 Betula nana Nordenskiöld Land Rusanovodden towards Colesbukta Nathorst 1882, O; IA & LL 1998; IA, LL et al. (2002) 1 1 2 Colesbukta, W, S sides Strandwitz 1930, TROM; TE & SS (1999) 1 2 5 1 9 Colesbukta, E, N sides Fries (1869); TE & SS 1986; TROM; IA, TE, LL, BS & MA 1998; IA & BS 1999 1 2 3 Colesdalen, N side TE & SS 1986, TROM; IA & LL 1998; IA & BS 1999, IA, LL et al. (2002) 1 3 3 7 Colesdalen, interior TE & SS 1986, TROM 1 1 Fardalen LL 1997 1 1 2 Grønfjorddalen AE (1990) 1 1 Hotellneset Vogt 1928, O 1 1 Endalen OS 1988, TROM; IA, TE, LL, BS & MA 1998 1 1 Todalen TE & AP 1970, TROM 1 1 Janssonhaugen TE 1970, TROM 1 1 Adventdalen, N side Högbom (1913); Hadač (1944); Sunding (1966); Lid (1967); TE & SS 1986, TROM; IA & LL 1998 1 3 6 10 Total 5 13 18 3 39 Appendix 1 The table below lists the locations and population sizes of 20 thermophilous vascular plant species in Svalbard. Localities within established protect- ed areas (Fig. 2) are in boldface. Names of fi eld- workers are abbreviated as follows: Inger Greve Alsos–IA; Mari Aasen–MA; Geir Arnesen– GA; Liv Borgen–LB; Christian Brochmann– CB; Torstein Engelskjøn–TE; Arve Elvebakk– AE; Reidar Elven–RE; Ivar Hauge–IH; Kjell Tor Hansen–KH; Leidulf Lund–LL; Arne Pedersen– AP; Olaf I. Rønning–OR; Hanna Resvoll-Dieset/ Resvoll-Holmsen–HR; Sigmund Spjelkavik–SS; Bjørn Erik Sandbakk–BS; Hans-Joachim Sch- weitzer–HS; Jan Thomas Schwenke–JS; Ola Skifte–OS; Kristine Westergaard–KW. Years following fi eldworkers’ names indicate when plant populations were located. Names fol- lowed by years in parentheses refer to sources in the reference list. See Table 5 for abbrevia- tions of herbaria. Population sizes (see Table 1) are large–L; medium–M; small–S. Nd stands for no data and ∑ is sum. 335Engelskjøn et al. 2003: Polar Research 22(2), 317–339 Calamagrostis stricta Bjørnøya Dispersed on plain TE (1987) 10 9 7 26 Sørkapp Land Hornsund, S side Dubiel 1985, TROM 1 1 Wedel Jarlsberg Land Hornsund, N side Triloff (1944) 2 2 Recherchefjorden Dunderbukta OR & OS 1960, TROM 2 2 Nathorst Land Midterhuken TE et al. (1972) 1 1 Akseløya TE et al. (1972) 1 1 Nordenskiöld Land Bellsund, Berzeliusdalen Dahl & Hadač (1946); TE & AP 1970; TE & JS 1987, TROM 1 2 3 6 Reindalen TE & AP 1970; CB & TE 1985; TE & SS 1986, TROM 3 4 7 De Geerdalen Hadač (1944); TE 1970 1 5 6 Adventfjorden, Advent- dalen, tributaries Hadač (1944); TE & AP 1970; TE & SS 1986; TE 1995, 1996, TROM 10 5 1 10 26 Bjørndalen Asplund (1919); IA, BS 2003, O 1 1 Colesbukta, Colesdalen TE & SS 1986, TROM; IA, LL et al. (2002) 1 8 3 1 13 Russekeila, Kapp Linné Dahl & Hadač (1946) 2 2 Sabine Land Sassendalen, N side RE & JS 1986, TROM 1 1 Bünsow Land Bjonadalen Asplund (1919) 1 1 Dickson Land Kapp Thordsen Dahl & Hadač (1946) 2 2 Hugindalen Lid (1967) 1 1 Oxaasfjellet Rønning (1972) 1 1 James I Land Kapp Wærn Nathorst (1883) 1 1 Oscar II Land Bohemanneset Lid 1924; Hadač 1939, O 1 1 Haakon VII Land Blomstrandhalvøya OR & OS 1958, TROM 1 1 Kongsfjorden, E side AE (1989); IA 1993 1 2 3 Liefdefjorden, S, W AE (1989); Möller (2000) 2 2 Total 12 33 21 43 108 Campanula rotundifolia Nordenskiöld Land Colesdalen, NE side Asplund 1915, O, Asplund (1919); IA, TE, LL, MA & BS 1998, 1999, TROM 1 1 Colesdalen, N side TE & SS 1986; LL 1997; IA, LL & BS 1998, TROM; IA & BS 1999; IA, LL et al. (2002) 1 1 2 Colesbukta towards Rusanovodden IA, LL et al. (2002) 1 1 Total 1 3 4 Carex marina ssp. pseudolagopina Nordenskiöld Land Sassendalen, S side AE & Eriksen 1988 , TROM 1 1 Sabine Land Sassendalen, N side Nathorst 1882, C; HS (1966); RE et al. 1986–89, O, TROM 6 6 Bünsow Land Gipsdalen CB, TE, AE & RE 1985; Eriksen 1987, O, TROM 1 1 5 7 Dickson Land Kapp Thordsen Dahl 1981, pers. comm. 1984 1 1 Haakon VII Land Liefdefjorden Thannheiser (1972) 1 1 Total 1 1 5 9 16 Empetrum nigrum ssp. hermaphroditum Wedel Jarlsberg Land Recherchefjorden Lynge 1926, O 1 1 Observatoriefjellet Elvebakk, pers. comm. 2002 1 1 Nathorst Land Van Keulenfjorden, Annahamna Lynge 1926, O 1 1 Van Keulenfjorden, Louisefjellet Lid 1920, O 1 1 Nordenskiöld Land Bellsund OR & OS 1958, TROM 2 1 3 Berzeliusdalen TE, AP & HS 1970, TROM 1 1 Species Population sizes Part of Svalbard Location Source, herbaria with voucher specimens L M S Nd ∑ 336 Twenty thermophilous vascular plant species in Svalbard Van Mijenfjorden, N, W, Camp Morton area, 30 - 40 m asl Holmboe (1910); AE & Hodin 1986, TROM 3 3 Reindalen, tributaries TE et al. (1972); CB, TE 1985, TROM; SS (1991) 1 3 3 1 8 Lundströmdalen SS (1991) 1 1 Van Mijenfjorden, N TE et al. (1972) 1 1 Grønfjorden area Fries (1869), Asplund (1919), Wirén (1922) 1 1 Hollendardalen Sunding (1966) 1 1 Colesbukta, both sides TE & SS 1986, TROM; TE & SS (1999); IA, TE, LL, BS & MA 1998; IA & KW 2002 3 2 2 7 Colesdalen, N side TE & SS 1986, TROM; TE & SS (1999), IA & SS 1999; IA, LL et al. (2002) 1 4 5 Adventfjorden, Adventdalen, tributaries Nathorst (1883); Hadač (1944); Sunding (1966), TE & AP 1970; GA & TE 1996, TROM; IA & LL 1998 4 1 1 6 Dickson Land Mimerdalen and Pyramiden Nathorst (1883); Högbom (1913); Möller, Thannheiser (1997); IA & LL 1998 1 1 Odindalen RE 1990, TROM 1 1 Kapp Wijk Ballye 1896, CGE 1 1 Kapp Thordsen 75 m asl RE 1992, TROM 1 1 James I Land Ekmanfjorden, Kapp Wærn Fries (1869); Asplund (1919) 3 3 Oscar II Land Bohemanneset Andersson & Hesselman (1900) 1 1 St. Jonsfjorden area Iversen & Koefoed 1923, BG, O 1 1 Ymerbukta Nathorst (1883) 1 1 Bertilfjellet Asplund (1919) 1 1 Kongsfjorden area Hofmann & Thannheiser (1972); Möller (2000); AE & SS (1995) 4 2 1 1 8 Haakon VII Land Liefdefjorden, Lernerøyane Thannheiser (1972); AE & SS (1995); Möller (2000) 2 ~10 ~12 Raudfjorden Iversen & Koefoed 1923, O 1 1 Albert I Land Smeerenburgfjorden Solheim et al. 1936, O 1 1 Krossfjorden, W side Hjelle 1964, O 1 1 Krossfjorden, E side Hofmann & Thannheiser (1972); AE & S (1995) 2 2 Ny-Friesland Wijdefjorden, E side Summerhayes & Elton (1928) 1 1 Mosselbukta Spicer 1964, O 1 1 Gustav V Land Nordaustlandet, Depotodden Brattbakk (1981, cited in AE & SS 1995) 1 1 Total 8 14 30 28 ~80 Euphrasia frigida Nordenskiöld Land Colesdalen IA & LL 1998, TROM, IA & LL (1999); IA & BS 1999 3 3 Colesbukta, E side IA, LL et al. (2002) 2 2 Haakon VII Land Bockfjorden, Trollkjeldene OS 1960, TROM, OR (1961) 1 1 Ossian Sarsfjellet KH, IA, BS 2003, TROM 1 1 Total 7 7 Hippuris vulgaris Bjørnøya N side, plain E (1986a) 2 7 6 15 W and SW sides, plain E (1986a) 3 4 7 Total 2 10 10 22 Juncus castaneus Nordenskiöld Land Longyeardalen Lid 1924, O 1 1 De Geerdalen HS (1966) 1 1 Sabine Land Sassendalen Nathorst (1883) 1 1 Species Population sizes Part of Svalbard Location Source, herbaria with voucher specimens L M S Nd ∑ 337Engelskjøn et al. 2003: Polar Research 22(2), 317–339 Gjelhallet Dahl 1981, O 1 1 Bünsow Land Gipsdalen Eriksen 1987, O, TROM; RE et al. (1990) 1 1 Total 1 4 5 Juncus triglumis Wedel Jarlsberg Land Recherchefjorden Turnbull (1900) 1 1 Nordenskiöld Land Sassenfjorden, S side Hadač (1944) 1 1 Adventdalen Hadač (1944); TE, SS 1986, TROM 2 1 6 9 Bjørndalen HR (1913) 1 1 Sabine Land Sassendalen Nathorst (1883); RE et al. 1986, TROM 1 5 6 Bünsow Land Gipsdalen CB, TE, AE, RE 1985, TROM 2 1 1 4 Dickson Land Mimerdalen to Dicksonfjorden Lid 1924; Lid (1925); RE 1990, O, TROM 1 5 6 Haakon VII Land Ossian Sarsfjellet AE 1988, TROM 2 2 Blomstrandhalvøya AE 1988, TROM 1 1 Andrée Land Purpurdalen Dahl, Hadač (1946) 1 1 Ny-Friesland Austfjordnes Spicer 1964, TROM 1 1 Wijdefjorden, E side AE 2002, pers. comm. 2002 6 6 Total 4 5 30 39 Kobresia simpliciuscula Bünsow Land Gipsdalen TE 1985, TROM; TE (1986b) 1 1 Dickson Land Mimerdalen Isachsen 1925, O; Høeg 1928, TRH 1 1 Adolf bukta AE 2001, pers. comm. 2001 1 1 Haakon VII Land Kongsfjorden AE 1988, TROM (1993) 1 1 2 Ny-Friesland Wijdefjorden, E side AE 2002, pers. comm. 2002 3 3 Total 1 3 4 8 Luzula wahlenbergii Nathorst Land Bromelldalen Lynge 1926, O 1 1 Nordenskiöld Land Berzeliusdalen TE, AP 1970; TE & JS 1987, TROM 2 2 Reindalen, tributaries Harper & Spicer 1965, O, TROM; TE et al. (1972) 3 2 5 Adventfjorden, Bjørn- dalen, Revneset, Longyearbyen Nathorst (1883); TE & HS 1970, TROM; Spicer 1965, TROM; Brosø 1996, TROM 1 2 2 5 Colesdalen TE & SS 1986, TROM 1 1 Total 1 8 5 14 Ranunculus arcticus Edgeøya Western coast Neilson (1970) 1 1 Sørkapp Land Sørkapp Kristoffersen 1930, TROM 1 1 Nathorst Land Midterhuken to Bellsund Malmgren 1864, O; TE et al. (1972) 1 1 2 Nordenskiöld Land Kolfjellet TE et al. (1972); AE et al. (1987) 1 1 De Geerdalen, outlet Hadač (1944) 2 2 Sabine Land Sassendalen, outlet, N RE 1986, TROM 2 2 Bünsow Land Gipsdalen, Tempelfjorden TE, CB, AE, RE & Hodin 1985, TROM 1 8 9 Dickson Land Kapp Thordsen, surroundings HR 1908, O; RE, AE (1996) 4 4 Oscar II Land Alkhornet HR 1908, O; OR, OS 1958, TROM 1 1 Haakon VII Land Krossfjorden Malmgren (1862) 1 1 Ossian Sarsfjellet AE 1999, TROM; IA, KH, BS 2003, TROM 1 1 Total 3 10 12 25 Ranunculus lapponicus Nathorst Land Bromelldalen TE et al. 1970, TROM; TE et al. (1972) 1 1 Species Population sizes Part of Svalbard Location Source, herbaria with voucher specimens L M S Nd ∑ 338 Twenty thermophilous vascular plant species in Svalbard Nordenskiöld Land Van Mijenfjorden, N Reindalen, Gangdalen Lynge 1926; Harper 1964, O; TE et al. (1972); CB & TE 1985, TROM; AE 1986 1 8 5 14 De Geerdalen, E, W sides Hadač (1944); TE 1970; RE 1987, TROM 2 6 8 Eskerdalen Hadač (1944) 1 1 Brentskardet Hadač (1944) 1 1 Revneset to Adventdalen, tributaries Nathorst 1868, O; Hadač (1944); Lid (1967); TE & AP 1970; TE & SS 1986; TE 1987, TROM 6 1 5 12 Bjørndalen Sunding 1960, O 1 1 Colesbukta, Colesdalen RH 1908, O; E & S 1986, TROM; AE 1986, IA, LL et al. (2002) 1 2 1 11 15 Sabine Land Sassendalen, N side Asplund 1915, O; RE & JS 1986, TROM; AE & Øvstedal 1987, TROM 4 4 Dickson Land Kapp Thordsen, Kapp Wijk Wilander & Nathorst 1870, O; Foged 1958, TROM; RE 1990, O, TROM 5 4 1 10 Oscar II Land Bohemanneset Wirén (1922); Lid 1924, O 1 1 Haakon VII Land Feiringfjell 5 m asl I. Brattbakk 1974, TRH 1 1 Ny-Friesland At Wijdefjorden Nathorst (1883) 1 1 Total 2 21 14 33 70 Ranunculus pallasii Nordenskiöld Land Stormyra, below Høgsnyta TE, AP 1970, TROM; TE et al. (1972) 1 1 Reindalssletta TE 1985, TROM 3 3 Adventfjorden, Adventdalen Lid 1924, O; OR 1959, TROM; HS (1966) 1 3 4 Kapp Laila TE 1986, TROM 1 1 Colesdalen, interior TE & SS (1999) 1 1 Oscar II Land Bohemanfl ya Lid 1924, O; RE, Andersen 1997, TROM 1 1 Total 1 5 2 3 11 Ranunculus wilanderi Dickson Land Kapp Thordsen Jørgensen 1896, O; GA & TE 1996 1 1 Total 1 1 Rhodiola rosea Bjørnøya Mainly N and E coast TE (1987) 2 4 20 2 28 Prins Karls Forland Central, south Rudmose Brown (1908) 1 1 Richardlaguna Rønning, pers. comm. 1985 1 1 Total 2 4 21 3 30 Rubus chamaemorus Nordenskiöld Land Rusanovodden Nathorst (1883); IA & LL 1998 1 1 SE of Rusanovodden IA, LL et al. (2002) 1 1 Colesdalen, Tenndammen Asplund 1915, O, Asplund (1919); Nilsen 1979, TROM; IA & LL 1998 1 1 Sabine Land Sassendalen HR (1913) 1 1 Dickson Land Kapp Thordsen RE, LB 1992, TROM; GA, TE & RE 1996 1 1 2 James I Land Ekmanfjorden, W side: below Ekmanfjellet, Hemsil river Nathorst (1883); Wirén (1922); Nilsen 1979, TROM; IA & LL 1998 2 2 Sveaneset Wirén (1922); IH 1998, pers. comm. 1998 1 1 Total 4 3 2 9 Salix lanata Nordenskiöld Land Adventdalen N, WSW of Innerhytta, ca. 70 m asl HS 1963, O, SS; HS 1964, TROM; HS (1966); Hultén (1964); TE & SS 1986; IA & LL 1998, TROM; LL 2001 1 1 Oscar II Land Ny-Ålesund, at Storvatn, 40 m asl (extirpated 1990–91) Aasgaard & OR 1974; OR 1991, TRH; AE 1976, pers. comm. 2002 1 1 Species Population sizes Part of Svalbard Location Source, herbaria with voucher specimens L M S Nd ∑ 339Engelskjøn et al. 2003: Polar Research 22(2), 317–339 Total 2 2 Vaccinium uliginosum Nordenskiöld Land Colesdalen Holmsen 1912, O; Finnseth 1936, TROM; LL 1997 (photo); IA, LL, BS, MA 1998, TROM; IA, BS 1999 1 1 Colesbukta towards Rusanovodden IA; LL et al. (2002) 1 1 Kreklingpasset Egge 1940, 1941, O; Nilsen 1981, TROM 1 1 Dickson Land Mimerdalen Högbom (1913); Høeg 1928, TRH; Möller & Thannheiser (1997) 1 1 Idodalen IA & LL 1998, TROM 1 1 Total 2 3 5 Species Population sizes Part of Svalbard Location Source, herbaria with voucher specimens L M S Nd ∑