Pine (Pinus sylvestris L.) Penetration towards the Head of the Handolan Valley: Recent Reversal of Long- Term Retrogressional Trend-Contrasting Responses to Climate Change of Tree-and Forest Line

Kullman L

Abstract

Pine (Pinus sylvestris L.) Penetration towards the Head of the Handolan Valley: Recent Reversal of Long- Term Retrogressional Trend-Contrasting Responses to Climate Change of Tree-and Forest Line With a climate-change perspective, this study focuses on the recent history and performance of the much separated pine (Pinus sylvestris L.) tree and forest lines in a mountain valley in the southern Swedish Scandes. Historical records define quite accurately these “lines” by the early 20th century and mid-1970s. Their subsequent dynamic performances have been surveyed up to the present day. Both lines are currently positioned within the subalpine mountain birch forest belt (Betula pubescens ssp. czerepanovii). Consequently, their past, present and future changes rely on the evolution of the birch forest matrix. Between the early 20th century and the mid- 1970s, the position of the pine forest- and tree lines remained fairly stable.