Future use and management of Swedish forests

Forest has always been of huge importance to Sweden. Over the past hundred years forest production has almost doubled. The growth curve pointed steadily upward until around 2013, when it began to dip.

Wallenberg Initiatives in Forest Research, WIFORCE

The program involves five appointments, one for each sub-project:

  • Forest management and biodiversity in terrestrial environments
  • Forest management and biodiversity in water-rich environments
  • Tools for structural and functional biodiversity evaluation
  • Mapping biodiversity using eDNA
  • Genetic biodiversity in relation to forest management

The program also includes a graduate school, enrolling more than 50 PhD students, of whom 14 will be industry PhDs.

Institution:
Swedish University of Agricultural Sciences

Grant:
SEK 462 million over twelve years
(2019–2030)

“No one can say right now what the reason for the current decline is or how long it will continue,” says Hjalmar Laudon, professor of forest landscape biogeochemistry.

This is one of the questions to be addressed in a program entitled Wallenberg Initiatives in Forest Research – WIFORCE. Another key issue is how increased forest growth can be combined with retention of biodiversity.

“We want to improve our fundamental knowledge of the forest ecosystem. This is also essential in order to manage and produce forest sustainably,” explains Göran Ericsson, Dean of the Faculty of Forest Sciences at the Swedish University of Agricultural Sciences (SLU).

Swedish forest growth continues to decline, yet forests are seen as a key part of the solution to the climate problem and are expected to meet the demand for traditional forest products, as well as provide resources for new, sustainable materials, serve as a carbon sink, aid water purification, form part of pristine nature and be available for recreation. Forested land is also supposed to accommodate wind farms, reindeer husbandry and mining of rare earth metals and other mineral resources.

Success factors turning into setback factors?

The WIFORCE research program at SLU is a continuation of the earlier Knut and Alice Wallenberg Foundation program on basic forest research in genetics, genomics and biotechnology, as well as forest management of the future. The program provides additional focus on biodiversity, along with a graduate school. It spans the rich diversity of individual species to the diversity of entire forest landscapes.

“The program centers on basic research to identify the underlying reasons why the forest grows as it does, and new ways of using forests sustainably on the basis of how soil, trees and the landscape interact and function,” says Sandra Jämtgård, associate professor of biology, who is heading Future Silviculture – the forest management part of the program.

Forest edge effects and regeneration are among the areas that will be studied.

Better management, better seedlings, fertilization, nitrogen deposition, rising carbon dioxide levels in the atmosphere, runoff and a warmer climate are factors believed to have contributed to increased forest growth.

“The problem is that we don’t know for sure, and we don’t know what the most important factors are. The same factors may also explain the decline – seedlings may have become more sensitive, nitrogen deposition, reduced fertilizer use, along with a warmer climate that gives drier air and soil may have a negative impact,” Laudon says.

It is clear that the decline in growth is related to water shortages, even though it does not rain or snow less than it did 20 years ago.

“It’s a complex system. That’s why we also want to study the interaction between winter climate, spring snow melt, water storage in soil and groundwater, water absorption by trees and drainage via watercourses,” Laudon explains.

Another focal point is what happens below the soil surface.

“The composition of fungal and bacterial communities also impacts growth and the best way of managing forests but is something we still know little about. Our collaboration with the other part of the program concerning forest biotechnology and genetics will be very valuable in this respect,” comments Jämtgård.

Lack of scientific data

Although forest research has been conducted at various experimental sites around Sweden for as long as 100 years in some cases, scientific knowledge about underlying mechanisms involved in various types of forest management is in many cases deficient, particularly in the context of a changing climate. The clear-cutting practiced since the 1950s is being increasingly called into question, and there is a need for new methods.

“In many cases our knowledge of the mechanisms underlying the impact we see from soil preparation, clearing and thinning, as well as use of nitrogen fertilizers, for example, is lacking,” says Torgny Näsholm, professor of ecophysiology. Factors such as rising carbon dioxide levels and temperatures, and changes in precipitation patterns also require more research.

“There has long been a gulf between people engaged in forest management and those of us specializing in biology and genetics. Few decisions have been based on knowledge generated by basic research. But we are now bridging this gap,” says Ove Nilsson, Director of Umeå Plant Science Centre (UPSC), whose emphasis is basic research in forest biology and forest biotechnology.

“There are some 30 or so research teams studying fundamental questions concerning growth, adaptation, breeding and genetics. These teams are involved in the program in various ways,” he explains.

Field experiments and AI

At Svartberget research station near Vindeln in the northern Swedish province of Västerbotten, researchers have access to monitoring data dating as far back as 1923 in some cases, and an infrastructure for field experiments in forest, water, air and soil. Many of the questions addressed under the program will be tested there, and at some of the other seven research sites located throughout Sweden. The tests will be carried out using data from some of the 2,000 or so field experiments that have been conducted over the years. More controlled experiments are being made and will be made in the UPSC laboratory, glasshouse and climate chamber. Here, one of the aims is to breed and develop traits in new seedlings that are better adapted to a changing climate.

Our focus is on knowledge development, so we gain a better understanding of the types of tree we should choose in the sustainable forest management of the future, and of the consequences of different kinds of forestry,” Ove Nilsson says.

Just as large-scale DNA sequencing technology and AI have revolutionized medicine, these technologies are now having the same impact on forest research. eDNA – environmental DNA – is a powerful research tool for studying all organisms present in collected samples.

“This will enable us to study all aspects of biodiversity. A water sample can tell us which fish are present in a lake. An air sample can tell us about all animals present in a zoo, for example, and a soil sample reveals information about tens of thousands of microorganisms,” says Nilsson.

The technology also enables the researchers to study how ecosystems are altered by different forms of forest management. One side-effect is that the efficacy of the technology generates huge quantities of data.

“We still have some way to go before we really understand how to use all this information. But we can see it is useful in order to examine changes and studies the dynamics,” Nilsson says.

Genetic diversity is another field in which technological strides are being made.

“It’s now possible to see how different trees in a forest are related to each other. We can study their diversity and, for example, how they cope with a warmer climate, their resistance to drought and diseases, and on that basis create breeding programs to produce seedlings and saplings that are better adapted to a changing climate.”

In essence, the program aims to conduct basic research to provide a basis for finding the right sorts of tree adapted to the places they will grow in combination with the management method best suited to those locations, taking biodiversity into consideration.

The third branch of the program is a graduate school for 50 PhD students.

“The graduate school is important in many ways. It will give us a network reaching out to other research fields within the Faculty of Forest Sciences. Our industry-sponsored PhD students will strengthen the network with input from industry and other stakeholders in the field,” says Nilsson, who is scientific director of the school, along with Hjalmar Laudon.

Text Carina Dahlberg
Translation Maxwell Arding
Photos
Carina Dahlberg, Fredrik Larsson

What is forest biodiversity?

Forest biodiversity is a term describing diversity within individual species, between species and of entire landscapes.