id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
fennia-3765	Heikkinen, Olavi; Tuovinen, Mervi; Autio, Jyrki	What determines the timberline?	2002	8	.pdf	application/pdf	3876	290	66	Temper- ature sums and lengths of various thermal seasons have also frequently been used to characterise tree lines (Tuhkanen 1980, 1984, 1993). The position of the arctic front in summer closely coincides with the northern timberline in Eurasia and Canada (Mitchell 1973; Tuhkanen 1993), while in Finn- ish Lapland the northern forest and tree lines are seen to be associated with effective temperature sums (Fig. 2).	cache/fennia-3765.pdf	txt/fennia-3765.txt