The Greenland vascular plant herbarium of the University of Copenhagen 1

By the establishment of the Greenland Botanical Survey in 1962 at the Botanical Museum, University of Copenhagen, an era of regular and systematic exploration of the vascular plant flora of Greenland was initiated and it ended in 1996, when funding ended. Preceding this period, the vascular plant flora was mainly known from the results of more sporadic botanical investigations mostly in low arctic West and East Greenland, but after the 1980s, investigations expanded to include the more inaccessible high arctic Northeast and North Greenland. Nowadays, vascular plant species have been collected from most regions of Greenland. So far, three regional phytogeographical studies of South, North, and West Greenland have been published, and at present, two papers dealing with the vascular plant flora of East Greenland are ready for publication. These studies will be the basis for a synopsis of the phytogeography of Greenland and a new edition of the Flora of Greenland. The published distribution maps from South, West, and North Greenland based on these collections have been digitized and used for modelling the regional vegetation and flora and its relation to past glaciations and current climate. The specimens from East Greenland have been entered into a database and will be available for future modelling projects.


Introduction
A detailed knowledge of flora and vegetation is a crucial prerequisite for ecological and environmental investigations.Our knowledge of the flora of Greenland has increased during the last five decades and regional phytogeographical (Bay 1992;Feilberg 1984;Fredskild 1996b) and plant sociological studies have been carried out (e.g., Böcher 1954Böcher , 1963;;de Molenaar 1974de Molenaar , 1976;;Daniëls 1982;Schwarzenbach 2000.Detailed knowledge on the distribution of plant species in the past and present is crucial when predicting the ecological impact of the changing climate in the Arctic.

Exploration of the flora of Greenland
The Greenland Herbarium of the University of Copenhagen is the world's largest collection of flowering plants, gymnosperms, and vascular cryptogams from Greenland.The total number of specimens is approximately 140 000 including 185 types, and with the Greenland collections in British Museum, University of Oslo, and Lancaster University, the number exceeds 150 000 specimens of vascular plants from Greenland.Much smaller collections of vascular plants are held in the Herbarium of the Naturkunde Museum Münster, Germany, and the Utrecht Herbarium now in the Naturalis Biodiversity Center Leiden, the Netherlands.The total number of species of vascular plant is approximately 520 (Böcher et al. 1978;Daniëls and van Herk 1984;Bay 1993;Solstad and Elven, in preparation;Struck 2013;Daniels 2015).
Collecting vascular plants in Greenland was initiated in 1735 when P. Egede made a book herbarium of plants collected in the vicinity of the capital Nuuk.In the early period in the 20th century, the expeditions went to the more accessible areas by the towns along the southwest coast of Greenland.The exploration of the flora of East Greenland started to intensify during the 1930s, and especially from the 1980s, the exploration of northern East Greenland and North Greenland was logistically possible.Systematic exploration of the flora was carried out in 1962-1996 when the Greenland Botanical Survey operated in most parts of Greenland (Fig. 1).
The latest edition of the flora of Greenland (Böcher et al. 1978) is planned to be revised and updated based on finds of new species (Bay 1993) and the increased knowledge on the distribution of plant species gained during the last decades.Since the last update, a few species have been added.Struck (2013) found Botrychium tenebrosum in South Greenland and a revision of the Carex saxatilis material from Greenland by R. Elven and coauthors, Oslo, showed that the North American species Carex membranacea also occurs in North and West Greenland.The Papaver material has been revised based on genetic and morphological studies by Solstad and Elven (in preparation) and four species are identified within the Papaver radicum complex: Papaver cornwallisense, Papaver dahlianum, Papaver labradoricum, and Papaver lapponicum.
The number of moss and lichen species from Greenland is approximately 700 and approximately 1000, respectively.In addition, the herbarium contains approximately 1500 species of fungi of which a total of approximately 15 000 specimens have been digitized recently.

The Greenland Botanical Survey
Greenland Botanical Survey at the University of Copenhagen was founded in 1962 with the purpose of collecting botanical material on yearly excursions to different parts of Greenland.A grant made it possible for a senior Greenland botanist to travel to areas mostly Arctic Science Downloaded from www.nrcresearchpress.com by Statsbiblioteket Tidsskriftafdelingen (4.125) on 02/26/18 For personal use only.
on the west coast of low arctic Greenland.Since the 1980s, it has been possible to work in Northeast and North Greenland when the logistic platforms of the Greenland Geological Survey made it possible to investigate the previously inaccessible areas in the high arctic parts.Nowadays, vascular plants have been collected from all districts of Greenland (Fig. 1) but many remote areas need to be investigated.Students from Danish universities were trained in identifying the flora and analyzing and classifying the vegetation of Greenland and graduated with a master or a Ph.D. degree in arctic botany.Since 1986 the budget was reduced and it was not possible to include students in the yearly excursions.The Greenland Botanical Survey was closed down in 1996 following the retirement of its leader B. Fredskild.For personal use only.
The focus was on collecting vascular plants but collections of bryophytes, lichens, and fungi were also brought to the herbarium and material was exchanged with other herbaria working with the Arctic flora.
The collecting strategy of the Greenland Botanical Survey was to collect specimens of all species at each locality visited typically during 5-8 days of field work.Altogether, approximately 31 100 specimens were collected during 1970-1996(Fredskild 1996a)).Besides the vascular plant collection, major collections from Greenland of bryophytes, lichens, and fungi are kept in the herbarium in Copenhagen.
The Greenland Herbarium in Copenhagen is a unique resource for documenting historical floristic diversity patterns in one of the areas in the world most heavily affected by global warming.Besides, the comprehensive material offers excellent opportunities for studying intraspecific variation along climatic gradients and impact on the biodiversity and the distribution of vascular plants.
Comparing the flora of Greenland with other arctic areas on the mainland of North America and Asia, it appears to have a unique position phytogeographical in the Arctic because it is an island and is situated between the two continents.The influx of diaspores to Greenland has limitations because vast areas of sea separate Greenland from the neighboring land areas.This gives Greenland a unique phytogeographical position in the Arctic.
The long-term perspective is not promising, as no botanists with extensive experience in the Greenland flora, vegetation, and phytogeography are curating or working taxonomically with the collections.

Applied botanical research in Greenland
In addition to papers dealing with species, genera, or other groups of plants, three phytogeographical papers have been published and two are under preparation."A phytogeographical study of East Greenland" is in progress (Bay, in preparation) that will be complemented by "Flora of the central fjord region" (Halliday, in preparation).Feilberg (1984) published a phytogeographical study of South Greenland including 346 distribution maps covering South Greenland northwards to 62°20ʹN.based on more than approximately 30 000 collections.Bay (1992) carried out a phytogeographical study of northern Greenland north of 74°N latitude presenting 218 maps based on approximately 25 000 collections.Fredskild (1996b) studied the collections from the intermediate area and published a phytogeographical study of the vascular plants of West Greenland (62°20ʹ-74°N) with 379 maps based on approximately 57 000 collections (Fig. 2).Based on these regional studies, a synopsis of the phytogeography of Greenland will replace the last phytogeographical synopsis published nearly 60 years ago (Böcher et al. 1959) now including decades of new floristic and phytogeographical data.
Greenland is the largest island in the world including all of the arctic biomes and has a relatively poor flora compared to adjacent areas in North America and Eurasia due to the difficulties of long-distance dispersal to an island.The published distribution maps from South, West, and North Greenland have been digitized and used for modelling (Normand et al. 2013).The specimens from East Greenland have been entered into a database and a paper is under preparation (Bay, in preparation) and the material will be available for future biological projects.The floristic database will be integrated into the GBIF data portal and the Arctic Flora Inventory securing data and making them available for future botanical research in the Arctic.
Several investigations have focused on describing and analyzing the vegetation.Böcher (1954Böcher ( , 1959Böcher ( , 1963) ) carried out substantial work especially in the Middle West Greenland, while Sørensen (1933), Gelting (1934), andSeidenfaden (1933) took care of investigating the flora and vegetation in Northeast Greenland.Daniëls (1975Daniëls ( , 1982) ) and de Molenaar (1974,1976) have analyzed and classified the vegetation in Southeast Greenland and Sieg et al. (2006) in West Greenland and North Greenland and contributed to the international vegetation classification system for the Arctic (Walker et al. 2016).We have contributed to For personal use only.
the circumpolar arctic vegetation map with vegetation knowledge from Greenland (CAVM Team 2003;Walker et al. 2005) and Arctic Vegetation Archive (Walker et al. 2013) plus Conservation of Arctic Flora and Fauna (Aronsson et al., in preparation;Talbot et al. 1999).Stewart et al. (2016) used the results of many of the vegetation studies for modelling the regional vegetation richness on plot and landscape scales and related it to past glaciations and current climate.
Since the 1980s the focus shifted from strictly floristic and vegetation studies to also include applied and monitoring research.Nowadays, botanical investigations are part of the environmental assessments carried out prior to surveying and exploitation of natural resources.They partly focused on the occurrence of endemic species, rare species, and the protected orchid species, partly on locating important habitats for herbivore bird and mammal species in order to reduce the impact on these plant groups and habitats by regulating the activities.In connection with oil exploration activities in Jameson Land in East Greenland, the vegetation was mapped in selected areas and the effects of experimental oil spills were investigated (Holt 1987).Mapping of biologically important areas in the national park of West and Southeast Greenland has been carried out (Christensen et al., in press).
Two vegetation monitoring programs are running on a 5 year basis in high arctic Northeast Greenland and in low arctic West Greenland.The results from 15 years of monitoring in Northeast Greenland will be synthesized by Stewart et al. (in preparation).
Since the mid-1970s, the impact of sheep farming in South Greenland has been surveyed and the results of the monitoring have been summarized by Damgaard et al. (2016).Daniëls et al. (2011) and Daniëls and de Molenaar (2011) monitored vegetation and flora changes in Southeast Greenland during the last 40 years.
A new edition of the Greenland Red List (Boertmann 2008) is under preparation and it will include data on the vascular plants species classified as candidates for the Red List (Boertmann and Bay, in preparation).Knowledge of the flora of Greenland has been used internationally as a contribution to the Arctic Red List (Aronsson et al., in preparation).
Detailed knowledge of the Greenland and arctic flora has been important in the participation in international arctic research projects such as Circumpolar Arctic Vegetation Mapping (CAVM Team 2003;Walker et al. 2005), Arctic Vegetation Archive (Walker et al. 2013), the Gloria project (Winkler et al. 2016), and a CAFF publication on the status of rare endemic species in the Arctic (Talbot et al. 1999).