We show that high-altitude southern Greenland, currently lying below more than 2
kilometers of ice, was inhabited by a diverse array of conifer trees and insects
within the past million years. The results provide direct evidence in support of
a forested southern Greenland. . .
The plant taxa suggest that this period had average July temperatures that exceeded
10°C and winter temperatures not colder than –17°C, which are the limits for northern
boreal forest and Taxus, respectively (1). Allowing for full recovery of the isostatic
depression that is produced by 2 km of ice, Dye 3 would have been ~1 km above sea
level. In combination, these factors suggest that a high-altitude boreal forest at
Dye 3 may date back to a period considerably warmer than present.
The taxa identified include trees such as alder (Alnus), spruce (Picea), pine (Pinus),
and members of the yew family (Taxaceae) (Table 1). Their presence indicates a northern
boreal forest ecosystem rather than today’s Arctic environment. The other groups
identified, including Asteraceae, Fabaceae, and Poaceae, are mainly herbaceous plants
and are represented by many species found in northern regions at present (Table 1).
The presence of these herb-dominated families suggests an open forest where heliophytes
The core from Dye 3, located almost exactly 2000 km to the southwest of the Kap København
Formation (Fig. 1A), therefore, provides direct evidence of a forested southerncentral
Greenland. The invertebrate sequences obtained from the Dye 3 silty ice are related
to beetles (Coleoptera), flies (Diptera), spiders (Arachnida), brushfoots (Nymphalidae),
and other butterflies and moths (Lepidoptera) (taxonomic identification probability
support between 50 and 99%).