Research
My research concerns: 1) precommercial thinning; 2) tropical rain forest silviculture; 3) afforestation of former farmland by natural regeneration, direct seeding or planting of birch (silver birch and downy birch) including growth and yield.

At the moment I am mainly focusing on precommercial thinning, and within this research area I am responsible, or jointly responsible, for two ongoing projects. According to the keywords of today in forestry, conventional pre-commercial thinning is not an optimal method. The productivity in precommercial thinning has not increased during the last 40 years, which means that the operation has become relatively more expensive than other silvicultural operations.

Therefore, we want to increase the biological knowledge regarding alternative precommercial thinning treatments, e.g. top-cutting or top-breaking of the secondary stems as well as strip cleaning (geometrical precommercial thinning). A deeper understanding of the response and interplay among main stems and secondary stems will hopefully be useful in the development of more efficient precommercial thinning methods. Within this area we are also cooperating with researchers in both forest technology and animal ecology as well as a few technology manufacturers.

Previously, I have been working primarily within research area (3) and my dissertation dealt with farmland afforestation by natural regeneration and direct seeding of birch. Within this area I am still doing some research work, evaluating the effect of various site preparation methods on the survival and development of planted birch seedlings.

In addition, in the last few years I have also been involved in research in tropical rain forest silviculture. The research has focused on i) better planned selective logging and silvicultural activities, to reduce damage and create healthier residual stands after logging; ii), research regarding silvicultural treatments to support regeneration of non-pioneer species in secondary tropical rain forests.

As a result of the research in areas (1) and (3), I have also got on to a sidetrack considering research on a pathogen on birch.

Teaching and supervising experience
I have primarily been giving lectures in pre-commercial thinning, forest regeneration and birch silviculture at basic and advanced courses in silviculture at the BSc- and MSc-programmes at the faculty, as well as at field study trips and research extension conferences. I have also jointly developed and administrated new formal and informal courses as well as a further education course.

At the moment, I am main supervisor for two PhD-students and one licentiate student. I have earlier been main supervisor for two PhD-students, and one licentiate student, who have passed the examination, and deputy supervisor for six PhD-students who have passed the examination. Furthermore, I have been supervisor for 13 passed degree projects, and I am supervising one ongoing degree project.

Referee reviewed papers

Romell, E., Hallsby, G., Karlsson, A. & Garcia, C. 2008. Artificial canopy gaps in a Macaranga spp. dominated secondary tropical rain forest - effects on survival and above ground increment of four under-planted dipterocarp species. For Ecol. and Manage. 255: 1452-1460.

Forshed, O., Karlsson, A., Falck, J. & Cedergren, J. 2008. Stand development after two modes of selective logging and pre-felling climber cutting in a dipterocarp rainforest in Sabah Malaysia. For. Ecol. and Manage. 255: 993-1001.

Vestlund, K., Nordfjell, T., Eliasson, L. & Karlsson, A. 2006. A decision support system for selective cleaning. Silva Fennica 40(2): 271 - 289.

Forshed, O., Udarbe, T., Karlsson, A. & Falck, J. 2006. Initial impact of supervised logging and pre-logging climber cutting compared with conventional logging in a dipterocarp rainforest in Sabah, Malaysia. For Ecol. and Manage. 221: 233-240.

Ligné D., Nordfjell, T. & Karlsson, A. 2005. New techniques for pre-commercial thinning - time consumption and tree damage parameters. International Journal of Forest Engineering 16 (2): 89-99.

Ligné D., Karlsson, A. & Nordfjell, T. 2005. Height development of Betula pubescens following precommercial thinning by breaking or cutting the treetops in different seasons. Scand. J. For. Res. 20: 136-145.

Fällman, K., Ligné, D., Karlsson, A. & Albrektson, A. 2003. Stem quality and height development in a Betula-dominated stand seven years after precommercial thinning at different stump heights. Scand. J. For. Res. 18: 145-154.

Witzell, J. & Karlsson, A. 2002. Anisogramma virgultorum on saplings of Betula pendula and Betula pubescens in a district of northern Sweden. For. Path. 32: 207-212.

Karlsson, A., Albrektson, A., Elfving, B. & Fries, C. 2002. Development of Pinus sylvestris main stems following three different precommercial thinning methods in a mixed stand. Scand. J. For. Res. 17: 256-262.

Karlsson, A. 2002. Site preparation of abandoned fields and early establishment of planted small-sized seedlings of silver birch. New Forests 23: 159-175.

Karlsson, A. & Albrektson, A. 2001. Height development of Betula and Salix species following pre-commercial thinning through breaking the tops of secondary stems: 3-year results. Forestry 74(1): 41-51.

Karlsson, A. & Albrektson, A. 2000. Height development of Betula and Salix species following precommercial thinning at various stump heights: 3-year results. Scand. J. For. Res. 15: 359-367.

Karlsson, A., Albrektson, A., Forsgren, A & Svensson, L. 1998. An analysis of successful natural regeneration of downy and silver birch on abandoned farmland in Sweden. Silva Fennica 32(3): 229-240.

Karlsson, A., Albrektson, A. & Sonesson, J. 1997. Site index and productivity of artificially regenerated Betula pendula and Betula pubescens stands on former farmland in southern and central Sweden. Scand. J. For. Res. 12: 256-263.

Karlsson, A. 1996. Site preparation of abandoned fields and early establishment of naturally and direct-seeded birch in Sweden. Studia Forestalia Suecica, No. 199, 25 pp.

Karlsson, A. 1996. Initial seedling emergence of silver birch and hairy birch on abandoned fields following different site preparation regimes. New Forests 11: 93-123.