Paleorecord of norway spruce


The oldest fossil remains of spruce are described under the name Picea protopicea, and originate in the upper Cretaceous epoch. Additional fossil specimens of spruce occur in the sediments of the Tertiary (P engleri in Paleogenian Baltic amber), and particularly the later Neogene, spanning the Miocene and Pliocene. The fossil evidence indicates a widespread occurrence of spruce taxa with epistomatic needles beginning in the lower Oligocene in the northern hemisphere. Contemporary species of Picea possessing this needle type (P. omorica, P. jezoensis) belong to Tertiary relics in the Mediterranean and sub-Mediterranean mountain regions of Eurasia (Mai 1995). However, species with amphistomatic needles (including P. abies) also adapted to changing climatic conditions (continentalization and climate cooling) and consequently occupied large geographic areas during the Quaternary.

According to Mai (1995), both the phylogeny as well as the contemporary occurrence of taxa of this species is characteristic of plants originating with the flora of mesic woodlands of cold temperate climates. During the Triassic, spruce was absent in dry and warm areas. Climate cooling in the late European Triassic was associated with a marked increase in the presence of spruce pollen in sediment cores (l.c. p. 216). During the Miocene, spruce played an insignificant role, whereas in the Pliocene it became an important, and sometimes dominant component of forest vegetation. This large difference in the proportion of spruce in pollen diagrams of the Neogene is of stratigraphic significance. In addition to other factors, it permits the separation of Miocene sediments from those of the Pliocene (OSZAST 1973).

The increase in spruce dominance in the Pliocene is a proxy for the large changes that occurred in the species composition of European flora at the threshold of the approaching ice age. In central Europe three other taxa of the species Picea were present throughout this period of vegetation change, namely, Serbian spruce (P. omorica) as well as two sub-species belonging to Norway spruce P. abies: P. abies ssp. abies and P. abies ssp. obovata - Siberian spruce.


Was this article helpful?

0 0

Post a comment