Correlations weighted by forest area in 2015 are figured. (a) Forest cover (fraction of total country area occupied by forests) in 2015 demonstrates a strong negative relationship with population density (weighted correlation -0.64, p < 10−4), (b) a strong relationship of opposed sign is found with the growing stock density (weighted correlation +0.54, p < 10−3) indicating that growing stock capitalisation has been stronger in countries with smallest forest areas, (c) A trade-off between forest cover and growing stock is accordingly evidenced (weighted correlation -0.56, p < 10−3).

https://doi.org/10.1371/journal.pone.0307614.g001

https://doi.org/10.1371/journal.pone.0307614.g002

Relationships between annual rates of change in the growing stock (2005–2015) against growing stock density (a), felling- to-net-increment ratio (c). Change in the growing stock (2005–2015) was also expressed per hectare (b) for a cross-comparison with (a). Acceleration in growing stock changes over the two successive periods 1990–2005 and 2005–2015 (difference, %.year–1) against initial growing stock changes (d). Weighted correlations are: (a) 0.00 (NS), (b) +0.36 (0.02), (c) -0.44 (p < 0.01), (d)– 0.59 (p < 10−4). NS correlations figured as dotted lines.

https://doi.org/10.1371/journal.pone.0307614.g003

Relationships between GDP per capita and felling and net increment rates (a, b), ratio of felling to net increment (c), and resulting changes in the growing stock over 2005–2015 (d) across European countries under study. Weighted correlations are: (a) +0.57 (p = 10−4), (b) + 0.48 (p < 0.01), (c) +0.42 (p <0.05), (c) -0.28 (p < 0.1). NS correlations figured as dotted lines.

https://doi.org/10.1371/journal.pone.0307614.g004

(a) economic development as measured by GDP.capita-1 (GDPc, euros) in 2013 across 39 countries (b) freedom in decision making as measured by the Property Rights Index in Forestry (PRIF, [42, 43]) in 2015 and available for 30 countries (see methods). Private ownership rate in 2010. Weighted correlations (forest area in 2015): (a) +0.8 (p < 10−8) and (b) +0.71 (p < 10−4).

https://doi.org/10.1371/journal.pone.0307614.g005

Relationships between the annual rates of wood exports and (a) felling rate, (b) felling-to-net increment ratio and (c) changes in the growing stock over 2005–15 across European countries under study. Both exports, felling and GS changes expressed as fractions (%) of GS volume in 2005. Weighted correlations (forest area in 2015): (a) +0.65 (p < 10–5), (b) + 0.49 (p < 0.01), (c) –0.34 (p < 0.05).

https://doi.org/10.1371/journal.pone.0307614.g006