A phytogeographical study of the vascular plants of West Greenland (62°20' - 74°00'N)

Abstract

Phytogeographically and climatically West Greenland includes parts of the low arctic and high arctic areas. The present vegetation and a summary of its history since the last glaciation based on pollen- and macrofossil analyses are briefly described. The determination of more than 55,000 herbarium sheets of native pha­nerogams has been checked. Before preparing the dot maps it was necessary to decide at which level taxonomically difficult genera, e.g. Antennaria, Draba, Poa, Puccinellia, and Stellaria would be treated. For all of these the criteria used are given. Dot maps have been prepared for 379 taxa. These maps have been grouped into 11 West Greenland distribution types, which clearly correlate with T. W. Böcher's biological distribution types (Böcher 1963).

The collecting intensity in the large area is rather uneven. This is illustrated by a map giving the number of collections at the 305 localities from which 50 or more collections are at hand. Another map giving the number of taxa at 29 well-investigated localities illustrates the species diversity in the region. Most low arctic local­ities have more than 130 taxa, with 215 at the richest locality (Godhavn/Qeqertarsuaq on Disko), while the number at no high arctic locality exceeds 150. Reference to the corresponding numbers in other parts of Greenland is given.

Based on the dot maps a new delimitation of West Greenland in floristic prov­inces and districts is presented. It differs somewhat from that in Grønlands Flora/The Flora of Greenland (Böcher & al. 1957, and later editions). The major al­teration is that the boundary between the low and high arctic phytogeographic provinces is now placed through north Disko - Nuussuaq. As a consequence of this the southernmost district in the high arctic is divided into an outer (NWso) and an inner province (NWsi). Minor alterations are suggested in the southern part of West Greenland.