Disputation i biologi med Matilda Lindmark
Fredag den 2 december försvarar Matilda Lindmark sin doktorsavhandling "Increased resilience in managed boreal forests: controlling damages by Spruce bark beetle and Moose in Sweden".
Handledare:
Bengt-Gunnar Jonsson, professor, Mittunversitetet
Opponent:
Jan-Olov Weslien, professor, Skogforsk
Betygsnämnd:
Professor Christer Björkman, SLU Uppsala
Dr. Ola Kåren, SCA Sundsvall
Dr. Märtha Wallgren, Skogforsk Uppsala
Seminariet kommer att hållas på svenska.
Delta på disputationen via Zoom
Sammanfattning
Skador i brukade skogar ökar och denna avhandling fokuserar på älgbete (Alces alces L.) och granbarkborre (Ips typographus L.) och pekar mot att en större blandning av olika trädslag kan minska skadenivåerna.
Bland annat skyddar granextrakt känsliga tallplantor mot älgbete. Och dofter från lövträd, gamla träd och blånadsvampar kan fungera som avskräckande doftämnen för att skydda känsliga granskogar mot angrepp av granbarkborre. Avhandlingen pekar även på att större inslag av tall i granskogar kan gynna granbarkborrens naturliga fiende, Myrbaggen. Till sist har vi också analyserat hur bakteriefloran i granved förändras efter angrepp av granbarkborrar vilket är en viktig pusselbit i en förbättrad kunskap om biologisk mångfald och granbarkborrens ekologi.
Abstract
A majority of the forests growing in Europe today is planted, or heavily affected, by human. The forest industry is important, harvesting forest for timber production, pulp and paper, cellulose raw material and renewable energy sources. Nevertheless, forest management have turned heterogenic natural forests into homogenous forest stand which are susceptible for damages. This thesis will focus on moose (Alces alces L.) browsing and attack of spruce bark beetle (Ips typographus L.) which both cause large economic damages. The result of this thesis is based on field experiment conducted in managed forests in Sweden. Moose browsing on vulnerable top shoots of young pines during wintertime is a problem in northern Europe. We found that extract of spruce (a lower preferable tree species) act as a natural and efficient browsing repellent. Spruce bark beetle attack large trees of spruce (Picea abies) throughout Europe. We evaluate field behavior of the beetles exposed to non-host- and fungal volatiles in the search for a more efficient protection of susceptible spruce stands. We also evaluate the predator:prey ratio in different forest stand, aiming for an increased biological control of spruce bark beetle in managed forests. At last, we investigate how bacterial community in wood change after attack of spruce bark beetle to contribute to the knowledge about spruce bark beetle ecology. Today, forest management need to shift to management towards higher structural diversity and thereby increased resilience to manage an ongoing climate change. Forestry products, carbon sequestration and social values are all important and there is an urgent need to find solutions and control forest damages. Results from this thesis pointing towards that a change in forest management toward higher tree species variation will increase resilience in managed forests and thereby reduce damages of both moose and spruce bark beetle.