As a way of thinking, sustainability is well suited to forestry, since forests have traditionally been seen as an asset that will benefit several generations. From a forest owner’s point of view, the most essential factor in climate change mitigation is ensuring that forests remain viable.
“Making sure that forests are in a fit state to grow is key. When trees fall, the carbon that has been stored in them is released,” says Jyrki Kangas, Professor of Forest Bioeconomy at the University of Eastern Finland.
The trees and soil in forests absorb carbon dioxide and act as carbon reservoirs. In principle, extending forest turnover times improves the carbon balance, but trees cannot be left to grow infinitely. The optimal time for harvesting, considering both forest productivity and the climate, is before tree growth begins to slow down and trees become more susceptible to damage. From the point of view of carbon binding, it is essential that forests produce wood as efficiently as possible. The faster a forest grows after a regeneration felling, the faster it will begin to store carbon.
“Forest owners have done a lot of good work over the years,” Kangas says. “The triumphant progress of Finnish forestry has also been a success story in climate change mitigation, both from the point of view of carbon sinks and the use of renewable raw materials.”
A better world for generations to come
Forest owners can do a lot to help maintain the viability of forests and minimize their susceptibility to damage. However, it is not always easy to perform forest management activities in a manner that is optimal for the climate. In Southern Finland, for example, forests are dominated by spruce, which reduces their albedo or reflection of solar radiation. This means that the thermal radiation of the sun is absorbed by the forest instead of being reflected back to space. From a climate point of view, spruce is used too much, but there is a natural explanation for its popularity: elks are greedy for birch and pine saplings.
“If 90% of a sapling stand where the saplings have only reached a height of half a metre is gobbled up by elks, who in their right mind would want to plant more birch trees,” Kangas laughs. His example is a true story.
“The important thing is to see forests as an asset that will be passed on to future generations, which comes naturally to forest owners. We should try to ensure that our children will live in a better world.”
Finnish forests grow back
Wood is a renewable resource. This means that when a forest is regenerated after a regeneration felling, the same hectare of forest land will soon begin to store carbon from the atmosphere. Wood can also be used to replace fossil-based products.
“When oil, coal or natural gas is burnt or used as a raw material, carbon that has been stored for millions of years is released into the atmosphere,” says Sami Oksa, Director, Stakeholder Relations, UPM Forest.
In the short term, felling trees releases carbon dioxide into the atmosphere, but the regenerated forest soon stores new carbon. According to calculations made by Natural Resources Institute Finland (Luke), a regenerated hectare of forest regains its status as a carbon sink after 17 years — and then continues as one for the entire life cycle of the trees. Products made of wood and wood-based raw materials are also an excellent means for storing carbon.
Amidst climate change discussions, forest owners may wonder whether using their forests is sustainable from a climate point of view. However, the felling of rain forests and the felling of Finnish forests are two very different phenomena. In Finland, forests are regenerated and forest land remains forest land even after felling.
much more at source: https://www.upm.com/articles/forest/20/good-forestry-is-also-good-for-the-climate/