The effects of timber harvest, forest fire, and herbivores on regeneration of deciduous trees in boreal pine-dominated forests

Published source details Den Herder M., Kouki J. & Ruusila V. (2009) The effects of timber harvest, forest fire, and herbivores on regeneration of deciduous trees in boreal pine-dominated forests. Canadian Journal of Forest Research, 39, 712-722.
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This study is summarised as evidence for the following.

	Action	Category
	Use prescribed fire after tree planting Action Link
	Use mechanical thinning before or after planting Action Link
	Fence to prevent grazing after tree planting Action Link

Use prescribed fire after tree planting

A replicated, controlled study in 2001-2008 in boreal forest in Finland (1
Den Herder, Kouki & Ruusila 2009) found no effect of burning on the height or mortality of tree seedlings. Tree heights were similar in burned and unburned plots for silver birch Betula pendula (50-70 cm), rowan Sorbus aucuparia (45-50 cm) and Eurasian aspen Populus tremula (35-40 cm), as were their mortality rates (54-55%, 8-12% and 27-30% respectively). Ten seedlings of each species were planted in 2002-2003 in each of three burned and three unburned plots (10 ×15 m). The burn treatment was applied in 2001. Data were collected in 2002-2008.
Use mechanical thinning before or after planting

A replicated, controlled study in 2001-2008 in boreal forest in Finland (Den Herder, Kouki & Ruusila 2009) found that thinning had mixed effects on the height and mortality of different tree species. In both burned and unburned sites, the height of silver birch Betula pendula was higher in thinned and clearcut (130-270 cm) than in unthinned plots (40-70 cm). Birch mortality was lower in thinned (5-10%) than in clearcut and control (25-55%). The height of rowan Sorbus aucuparia was similar in all treatments in both burned and unburned plots (40-70 cm). Rowan mortality was higher in clearcut (50%) than in thinned and unthinned plots (5-15%) in unburned, and similar in all treatments in burned sites (5-15%). The height of Eurasian aspen Populus tremula was higher in thinned and clearcut (70-80 cm) than in unthinned (30-35 cm) in both burned and unburned. Aspen mortality was higher in unthinned (30%) than in thinned and clearcut (10-15%) in burned, and similar in all treatments in unburned sites (10-30%). Ten seedlings of each species were planted in 2002-2003 in each of three treatment plots (10 ×15 m): clearcut, thinned (50 m³/ha green-tree retention) and unthinned, replicated in three burned (in 2002) and in three unburned sites (total of 18 plots). Treatments were applied in 2001-2002. Data were collected in 2002-2008.
Fence to prevent grazing after tree planting

A replicated, controlled study in 2001-2008 in boreal forest in Finland (Den Herder, Kouki & Ruusila 2009) found that exclusion of moose Alces alces and hares Lepus spp. had mixed effects on the height of different tree species, but no effect on their mortality. The height of Eurasian aspen Populus tremula was higher in moose and hare exclusion plots (60 cm) than in moose exclusion and control plots (40 cm). Eurasian aspen mortality was similar in all treatments (17-33%). Height (50-70 cm) and mortality (45-75%) of silver birch Betula pendula were similar in all treatments as were the height (45-60 cm) and mortality (0-15%) of rowan Sorbus aucuparia. Ten seedlings of each species were planted in 2002-2003 in each of three treatment plots (10 ×15 m): control, moose exclusion (fence mesh size 15 cm) and moose and hare exclusion (fence mesh size 5 cm), replicated in three sites. Treatments were applied in 2002. Data were collected in 2002-2008.