Achim Grelle högt upp i en mast.

A new research project will study if continuous cover forestry sequesters more carbon than clearcutting forestry

Can continuous cover forestry bring us closer to the climate goals? Achim Grelle, professor of forest management with specialization in benefits to climate from forests, at Linnaeus University, will study this over the upcoming four years. Formas has granted research funds for research on new forms of silviculture and SEK 6.2 million goes to the project “CONFLICT – Can Continuous Cover Forestry Lead to Increased Carbon uptake of Terrestrial ecosystems?”

Cultivated forests take up great quantities of carbon dioxide from the atmosphere, while supplying renewable material that can substitute fossil matters. However, after logging, clear-cuts release carbon dioxide for many years before the net uptake of carbon dioxide starts over in the regrowing forest. It is now being intensely discussed in the scientific community and the forestry sector whether continuous cover forestry can be a beneficial alternative, by avoiding clear-cut phases that lead to emissions.

“If it is possible to reach a satisfactory growth and timber production through continuous cover forestry, it could actually lead to increased carbon sequestration in the long term, not least in forest soils”, Achim Grelle says.

Keep track of the carbon dioxide

Picture of mast

In this project carbon dioxide flows between a continuous cover forest and the atmosphere will be measured by placing advanced measuring equipment above the treetops on a 36 meter high tower set up in the forest. The sensors will “keep track of the forest’s breath” by continuously measuring the movements in the air and its carbon dioxide content, ten times per second, year-round. This way, the researchers can determine what quantities of carbon dioxide go into and out of the forest. By also studying the weather and the ground conditions, it will be possible to see what affects the flows of carbon dioxide. The carbon balance will then be compared with the average carbon uptake in clear-cut forests throughout their rotation period.

“In order to meet the climate goals, we must reduce emissions and increase the uptake of carbon dioxide. Here, the forestry sector has great potential to contribute if new forms of forest management can increase the net sequestration of carbon”, Grelle continues.

Continuous cover forestry can also benefit biodiversity

Today, not much is known about the climate benefits of continuous cover forestry, and no measurements have been done in existing stands that often are too small for such experiments. The researchers’ data will contribute with new knowledge to the ongoing discussion. It is also believed that biodiversity will benefit from continuous cover forestry with multi-layered stands.

You have received SEK 6.2 million in research funds from Formas. How does that feel?

“Back in 1995, when I first measured carbon dioxide emissions at a clear-cut area in Uppland, I started nourishing a dream of a research project in a continuous cover forest. It feels great that this finally becomes a reality!”, Grelle concludes.