Review of SJFR Volume 29, Issue 3, 2014
The amount of Dead Wood in a forest depends on how it is defined
The amount of dead wood is an important indicator of sustainable forest management. However, a common, standard measure is lacking. In a survey based on the Swedish National Forest Inventory, the amount of dead wood recorded was 10.9 m3 per hectare when measured using the standard definition, which includes lying dead wood only when its diameter is greater than 10 cm. If all dead wood down to a diameter of 1 cm was included, the amount increased to 25 m3.
“Same procedure as last year”, despite storm Gudrun
Storm “Gudrun” struck Sweden in 2005 and felled 75 million m3. After the storm, many forest owners were warned not to continue planting only spruce, and instead to diversify the composition of their forest. This study concludes that forest owners primarily relied on experience-based knowledge, and ignored warnings of abstract risk. The forest owners still considered spruce to be a less risky alternative than other tree species.
Retention Cutting triggers Coarse Root Growth by the remaining trees
Studies of tree growth after thinning and retention cutting have mostly focused on above-ground biomass. However, Pretzsch et al. excavated the soil so that they were also able to measure how root growth was affected by release. They found a significant increase in the resource allocation to the root system of the remaining trees. This means that the trees become mechanically stabilised after cutting. The study examined black spruce in Ontario.
High Browsing Pressure around Artificial Feeding Sites
Norway spruce is usually not preferred by browsing deer, but it is not spared if the browsing pressure is high enough. A study in southern Sweden showed that browsing is high around artificial feeding sites. If there is a shortage of alternative fodder around such sites, browsing on spruce is found as far away as 205 m from the feeding site. However, if there is an abundant field layer and deciduous trees around the site, spruce is not browsed at all.
High potential for Energy Wood when using tree tops
A Finnish study investigated the effects of different bucking and delimbing methods on pulpwood and energy wood yields in young thinning stands. They showed that, during whole-tree harvest, the energy wood yield could increase by 36-65 % if the minimum top diameter for pulpwood increased from 6-7 cm to 8 cm. If it increased to 10 cm, the energy wood yield is more than doubled.
