Skoggrænsens og sneliniens større høide tidligere i det sydlige Norge

Abstract

Forkortet: In the mountainous regions of the Southern Norway, logs and roots of the red fir (pinus sylvestris) are found in the bogs much higher, than this tree grown here, at the present day. This is mentioned by many observers in the preceding century. On the Hardangervidda, a mountain plateau at 60\u00B0 N such subfossil wood is found in many places up to elevations of 1350 m above the level of the sea, or about 450 m above the present highest limit of the red fir here. On the Hardangervidda the upper limit of the red fir is lowered 450 m, at the Hallingskarvet more than 260 m and on Dovre more than 300 m. Three causes have been mentioned as having chiefly effected this: 1. The rise of the land. 2. The destruction of the forest by man. 3. The deterioration of the climate. During the latter part of the Post-Glacial period the rise of the land in these regions does not reach more than 30-50 m, consequently this cause is quite inadequate as having effected a fall in the forest line of 350-400 m. Next, the exhaustion of the forests in Norway are certainly considerable, but still not sufficient to explain the great fall of the upper limit of the fir. Besides this, at the present time, in Norway, the fir at its upper boundary line, is slowly dying out.