The proportion of large-diameter trees in Finland has more than doubled in the past 60 years, according to the Finnish Forest Association.
One-fifth of the growing stock in Finland is now “stout” trees – having a diameter of more than 30cm.
Since the 1950s, the volume of stout spruces and broadleaved trees has quadrupled. Now, a quarter of spruce volumes are stout trees.
The share of pine stout trees among all pine has actually decreased.
The Finnish Forest Research Institute said prior to the 1950s the larger trees had been continuously removed in a process of selection, contrasting to the current even-aged forest growing policy, with thinning of only the smallest and lowest quality trees.
Another reason for increasing number of large-diameter trees is less timber being felled than the annual allowable cut. In 2010, 55 million m³ was felled, with the maximum sustainable annual felling rate at 70 million m³.
