A morphometric study of the geographic variation in Pinus contorta (Pinaceae)

Abstract

This morphometric study of the geographic variation in Pinus contorta is based on 93 provenances cultivated in northern Jutland, Hjardemål Klitplantage, 57'04“08'48‘E (Arboretum trial no. F275). The numerical methods employed were common principal components analysis (CPCA), non‐metric multidimensional scaling (MDSCALE), minimum spanning trees (MST), and the neighbour‐joining method (NJOIN). Although it is not always possible to draw a very clear line between the coastal var. contorta and the inland var. latifolia of P. contorta subsp. contorta, these varieties are distinct in their extreme forms. Critical provenances of both varieties seem to originate from the transition zone between the two taxa. The Californian or Sierra Nevada provenances of f contorta subsp. murrayana are very distinct from the Oregon provenances. Apparently most of the inland Oregon provenances of P. contorta are more or less intermediate between var. latifolia and subsp. murmyana s.str. The NJOIN method of phylogenetic reconstruction supports the division of P. contorta into two major groups or subspecies: 1. subsp. contorta, divided into var. contorta and var. latifolia, and 2. subsp. murrayana.