Urban Nilsson

Urban Nilsson
Professor in Silviculture


My current research interests are about how to manage Swedish forests for specific goals. Apart from management for maximized economic return, which I have been involved in during my entire research career, I am interested in forest management for increased biodiversity, increased recreational values and mitigation and adaptation to climate change. Examples of research areas are management of mixed species forests, combination of forest- and food production for moose and deer, continuous cover forestry, fast growing broadleaves and Scots pine in southern Sweden.
I am currently the leader of the silvicultural program in the research program Trees and Crops for the Future (TC4F). In TC4F, my involvement includes research on mixed species stands, comparison of production and biodiversity in Scots pine and Norway spruce, fast growing broadleaves, models of site productivity and continuous cover forestry.


My research career started with a focus on forest production and economy. In the 1990s I was involved in research about forest regeneration. Mainly planting of Norway spruce but also natural regeneration of our major tree species Scots pine, Norway spruce and birch. I was also involved in projects about regeneration of beech and oak.
In 2000, I started as a leader of the Norway spruce research program. The research program was mainly oriented towards production and economy in planted Norway spruce in southern Sweden but research about biodiversity in Norway spruce forests was also included. The research program ended in 2005. Thereafter, I was the leader of the southern part of the research program Theme Growth. This research program was oriented towards production and economy in our tree major native tree species and also in introduced tree species such as lodgepole pine, hybrid larch and Douglas fir. In 2009, Theme Growth was incorporated in the much bigger research program Future Forests and I have since then been involved in the multidisciplinary research of Future Forests.

Publikationer i urval

  1. Subramanian N, Bergh J., Johansson U., Nilsson, U. 2016. Adaptation of Forest Management Regimes in Southern Sweden to Increased Risks Associated. Forests 2016, 7, 8, doi:10.3390/f7010008
  2. Felton A, Nilsson U, Sonesson J, Felton AM, Roberge J-M, Ranius T, Ahlström M, Bergh J, Björkman C, Boberg J, Drössler L, Fahlvik N, Gong P, Holmström E, Keskitalo C, Klapwijk MJ, Laudon H, Lundmark T, Niklasson M, Nordin A, Pettersson M, Stenlid S, Stens A, Wallertz K. 2016. Replacing monocultures with mixed-species stands: Ecosystem service implications of two production forest alternatives in Sweden. Ambio, 45(Suppl. 2), S124–S139, DOI 10.1007/s13280-015-0749-2
  3. Holmström E, Hjelm K, Johansson U, Karlsson M, Valkonen S, Nilsson U, 2016. Pre-commercial thinning, birch admixture and sprout management in planted Norway spruce stands in South Sweden, Scandinavian Journal of Forest Research, DOI:10.1080/02827581.2015.1055792
  4. Urban Nilsson, Mattias Berglund, Jonas Bergquist, Hampus Holmström & Märtha Wallgren 2016: Simulated effects of browsing on the production and economic values of Scots pine (Pinus sylvestris) stands, Scandinavian Journal of Forest Research, DOI:10.1080/02827581.2015.1099728
  5. Subramanian N, Karlsson P-E, Bergh J, Nilsson U, 2015. Impact of Ozone on Sequestration of Carbon by Swedish Forests under a Changing Climate: A Modeling Study. Forest Science, 61, 445-457.
  6. Bergh, J., Nilsson, U., Allen, H.L., Johansson, U., Fahlvik, N. 2014. Long-term responses of Scots pine and Norway spruce stands in Sweden to repeated fertilization and thinning. Forest Ecology and Management, 320, 118-128.
  7. Ahnlund-Ulvcrona, K,. Ulvcrona, T., Nilsson, U. & Lundmark, T. 2014. Stand density and fertilization effects on aboveground allocation patterns and stem form of Pinus sylvestris in young stands. Scandinavian Journal of Forest Research, 29, 197-209.
  8. Gundale, M.J., Kardol, P., Nilsson, M-C., Nilsson, U., Lucas, R.W., Wardle, D.A. 2014. Interactions with soil biota shift from negative to positive when a tree species is moved outside its native range. New Phytologist 202, 415-421.
  9. Drössler, L., Nilsson, U. & Lundqvist, L. 2013. Simulated transformation of even-aged Norway spruce stands to multi-layered forests: an experiment to explore the potential of tree size differentiation. Forestry, 87, 239-248.
  10. Wallentin, C. & Nilsson, U. 2013. Storm and snow damage in a Norway spruce thinning experiment in southern Sweden. Forestry, 87, 229-238
  11. Hedwall, P-O., Grip, H., Linder, S., Lövdahl, L., Nilsson, U.& Bergh, J. 2013. Effects of clear-cutting and slash removal on soil water chemistry and forest-floor vegetation in a nutrient optimised Norway spruce stand. Silva Fennica 47: 1-16
  12. Koch Widerberg, M., Ranius, T., Drobyshev, I., Nilsson, U. & Lindbladh, M. 2012. Increased openness around retained oaks increases species richness of saproxylic beetles. Biodiversity and Conservation 21: 3035-3059.
  13. Egbäck, S., Liziniewicz, M., Högberg, K-A., Ekö, P-M., Nilsson, U. 2012. Influence of progeny and initial stand density on growth and quality traits of 21 year old half-sib Scots pine (Pinus sylvestris L.). Forest Ecology and Management 286: 1-7.
  14. Johansson, K., Nilsson, U., Örlander, G. 2012. A comparison of long-term effects of scarification methods on the establishment of Norway spruce. Forestry 86: 91-98
  15. Nilsson, U., Elfving, B., Karlsson, K. 2012. Productivity of Norway spruce compared to Scots pine in the interior of northern Sweden. Silva Fennica, 46, 197-209.
  16. Skovsgaard, J-P., Nilsson, U., Johansson, U. 2011. Ecology and silviculture of SPRUCE. Scand. J. For. Res. 26: 1-2
  17. Ahnlund Ulvcrona, K., Kiljunen, N., Nilsson, U., Ulvcrona, T. 2011. Tree mortality in Pinus sylvestris stands in Sweden after pre-commercial thinning at different densities and thinning heights. Scand. J. For. Res. 26: 319-328
  18. Wallentin, C. & Nilsson, U. 2011. Initial effect of thinning on stand gross stem-volume production in a 33-year-old Norway spruce (Picea abies (L.) Karst.) stand in southern Sweden. Scand. J. For Res. 26: 21-35.
  19. Nilsson, U., Fahlvik, N., Johansson, U., Lundström, A., Rosvall, O. 2011. Simulation of the effect of intensive forest management on forest production in Sweden. Forests 2: 373-393
  20. Bergh, J., Nilsson, U., Kjartansson, B. and Karlsson. 2010. Impact of climate change on the productivity of silver birch, Norway spruce and Scots pine stands in Sweden with economic implications for timber production. Ecological Bulletins 53: 185-196
  21. Nilsson, U., Luoranen, J., Kolström, T., Örlander, G. & Puttonen, P. 2010. Reforestation with planting in northern Europe. Scandinavian Journal of Forest research 25: 283-294.
  22. Nilsson, U., Agestam, E., Ekö, P-M., Elfving, B., Fahlvik, N., Johansson, U., Karlsson, K., Lundmark, T., Wallentin, C. 2010. Thinning of Scots pine and Norway spruce monocultures in Sweden – Effects of different thinning programmes on stand level gross- and net stem volume production. Studia Forestalis Suecica 219: 1-46.
  23. Jyske, T., Kaakinen, S., Nilsson, U., Vapaavuori, E., 2010. Effects of timing and intensity of thinning on wood structure and chemistry in Norway spruce. Holzforschung, 64: 81-91.
  24. Albaugh, T.J., Bergh, J.,Lundmark, T.,Nilsson, U., Stape, J-L., Allen, H L,.Linder, S. 2009. Utility of biological expansion factors in estimating above ground component biomass for Picea abies. For. Ecol. Manage. 258: 2628-2637.
  25. Kaakinen, S., Piispanen, R., Lehto, S., Metsometsä, J., Nilsson, U., Saranpää, P., Linder, S. & Vapaavuori. E. 2009. Growth, wood chemistry and fibre length of Norway spruce in a long-term nutrient optimisation experiment. Canadian Journal of Forest Research 39: 410-419.
  26. Bergh, J., Nilsson, U., Grip, H., Hedval, P-O., Lundmark, T. 2008. Effects of frequency of fertilisation on production, foliar chemistry and nutrient leaching in young Norway spruce stands in Sweden. Silva Fennica, 42, 721-733.
  27. Pfister, O., Nilsson, U. & Gemmel, P. 2008. Influence of gaps on some selected tree characteristics of edge trees in Norway spruce plantations. Forest Ecology and Management 255, 2643-2649.
  28. Pfister, O., Walentin, C., Ekö, P-M. & Nilsson, U. 2007. Silviculture in Norway spruce (Picea abies) stands with wide spacings – effects on wood quality. Scandinavian Journal of Forest Research 22, 333-343.
  29. Nilsson, U. & Gemmel, P. 2007. Growth in supplementarily planted Picea abies regenerations.  Scandinavian Journal of Forest Research 22, 160-167.
  30. Johansson, K., Nilsson, U. & Allen, H.L. 2007. Interactions between soil scarification and Norway spruce seedling types. New Forests 33, 13-27.
  31. Nordborg, F., Nilsson, U., Gemmel, P. & Örlander, G. 2006. Carbon and nitrogen stocks in soil, trees and field vegetation in conifer plantations 10 years after deep soil cultivation and patch scarification.   Scandinavian Journal of Forest Research 21, 356-363.
  32. Johansson, K., Örlander, G. & Nilsson, U. 2006. The effects of mulching on competing vegetation, growth and damage by pine weevil in young plantations of Norway spruce (Picea abies L. Karst.). Canadian Journal of Forest Research 36, 2377-2385.
  33. Nilsson, U., Örlander, G. & Karlsson, M. 2006. Establishing mixed forests in Sweden by combining planting and natural regeneration - effects of shelterwoods and scarification. Forest Ecology and Management 237, 301-311.
  34. Agestam, E., Karlsson, M. & Nilsson, U. 2005. Mixed forests as a part of sustainable forestry in Sweden. Journal of Sustainable Forestry 21, 101-117.
  35. Fahlvik, F., Agestam, E., Nilsson, U. & Nyström, K. 2005. Simulating the influence of initial stand structure on the development of young mixtures of Norway spruce and birch. Forest Ecology and Management 213, 297-311.
  36. Johansson, K., Söderbergh, I., Nilsson, U. & Allen, H. L. 2005. Effects of scarification and mulch on establishment and growth of six different clones of Picea abies. Scandinavian Journal of Forest Research 20, 421-430.
  37. Karlsson, M. & Nilsson, U. 2005. The effects of scarification and shelterwood treatments on naturally regenerated seedlings in southern Sweden. Forest Ecology and Management 205, 183-197.
  38. Petersson, M., Örlander, G., & Nilsson, U. 2004. Feeding barriers to reduce damage by Pine weevil (Hylobius abietis). Scandinavian Journal of Forest Research 19, 48-59.
  39. Nilsson, U. & Örlander, G. 2003. Response of newly planted Norway spruce seedlings to fertilisation, irrigation and herbicide treatments Annals of Forest Science 60:637-643.
  40. Nordborg, F. & Nilsson, U. 2003. Growth and net nitrogen uptake in Picea abies (L.) Karst. seedlings, effects of fertilization and site preparation. Annals of Forest Science 60, 657-666.
  41. Nordborg, F., Nilsson, U. & Örlander, G. 2003. Effects of different soil treatments on growth and net nitrogen uptake of newly planted Picea abies (L.) Karst. seedlings. Forest Ecology and Management 180, 571-582.
  42. Bergquist, J., Örlander, G. & Nilsson, U. 2003. Interactions among forestry regeneration treatments, plant vigour and browsing damage by deer. New Forests 25, 25-40.
  43. Agestam, E., Nilsson, U. & Wellander, T. 2003. The effect of shelterwood density and site preparation on natural regeneration of Fagus sylvatica in southern Sweden. Forest Ecology and Management 176, 61-73.
  44. Nilsson, U. & Allen, H.L. 2003. Short- and long-term effects of site preparation, fertilization and vegetation control on growth and stand development of planted loblolly pine. Forest Ecology and Management 175, 367-377.
  45. Nilsson, U., Albaugh, T.J. & Allen, H.L. 2002. Development of growth and stand structure prior to the onset of density dependent mortality in fertilized and irrigated loblolly pine stands Canadian Journal of Forest Research 32, 989-996.
  46. Karlsson, M., Nilsson, U. & Örlander, G. 2002. Natural regeneration on clearcuts – effects of scarification, slash removal and year of cutting. Scandinavian Journal of Forest Research 17, 131-138.
  47. Högbom, L., Nilsson, U. & Örlander, G. 2002. Nitrification and nitrogen utilization after clearfelling as monitored by the in vivo nitrate reductase activity (NRA) bioassay and natural abundance of 15N. Forest Ecology and Management 160, 273-280.
  48. Nilsson, U. Wellander, T., Gemmel, P., Johansson, U. & Karlsson, M. 2002. Natural regeneration of Norway spruce, Scots pine and birch in Norway spruce shelterwoods of varying densities on a mesic-dry site in southern Sweden. Forest Ecology and Management 161, 133-145
  49. Langvall, O., Nilsson, U. & Örlander, G. 2001. Frost damage to planted Norway spruce seedlings – influence of site preparation and seedling type. Forest Ecology and Management 141, 225-237.
  50. Béland, M., Agestam, E., Ekö, P-M, Gemmel, P. & Nilsson, U. 2000. Effects of scarification and seedfall on natural regeneration of Scots pine under two shelterwood densities in southern Sweden. Scandinavian Journal of Forest Research 15, 247-255.
  51. Bergquist, J. Örlander, G. & Nilsson, U. 1999. Slash removal and deer browsing affects field vegetation on south Swedish clearcuts. Forest Ecology and Management 115, 171-182.
  52. Nilsson, U. & Örlander, G. 1999. Vegetation management on grass-dominated clearcuts planted with Norway spruce in southern Sweden. Canadian Journal of Forest Research 29, 1015-1026.
  53. Nilsson, U. & Örlander, G. 1999. Water uptake by planted Picea abies in relation to competing field vegetation and seedling rooting depth on two grass-dominated sites in southern Sweden. Scandinavian Journal of Forest Research 14, 312-319
  54. Örlander, G. & Nilsson, U. 1999. Effects of reforestation methods on pine weevil (Hylobius abietis) damage and seedling survival. Scandinavian Journal of Forest Research 14, 341-354.
  55. Löf, M., Gemmel, P., Nilsson, U. & Welander, T. 1998. The influence of site preparation and interspecific competition on initial growth of Quercus robur L. Seedlings in a southern Sweden clear-cut and shelterwood. Forest Ecology and Management 109, 241-249.
  56. Örlander, G., Nilsson, U. & Nordlander, G. 1997. Pine weevil abundance on clear-cuttings of different ages: a 6-year study using pitfall traps. Scandinavian Journal of Forest Research 12, 225-240.
  57. Örlander, G., Nilsson, U. & Hällgren, J-E. 1996. Competition for water and nutrients between ground vegetation and planted Norway spruce. New Zealand Journal of Forest Science 26, 99-117.
  58. Nilsson, U., Gemmel, P. & Hällgren, J-E. 1996. Competing vegetation effects on initial growth of planted Picea abies. New Zealand Journal of Forest Science 26, 84-98.
  59. Gemmel, P., Nilsson, U. & Welander, T. 1996. Development of oak and beech seedlings planted under varying shelterwood densities and with different site preparation methods in southern Sweden. New Forests 12, 141-161.
  60. Nilsson, U., Gemmel, P., Löf, M. & Welander, T. 1996. Germination and early growth of sown Quercus robur L. in relation to soil preparation, sowing depths and prevention against predation. New Forests 12, 69-86.
  61. Nilsson, U. & Örlander, G. 1995. Effects of some regeneration methods on drought damage of newly planted Norway spruce seedlings. Canadian Journal of Forest Research 25, 790-802.
  62. Nilsson, U. & Albrektson, A. 1994. Growth and self-thinning in two young Scots pine stands planted at different initial densities. Forest Ecology and Management 68, 209-215.
  63. Nilsson, U. 1994. Development of growth and stand structure in Picea abies stands planted at different initial densities. Scandinavian Journal of Forest Research 9, 135-142.
  64. Nilsson, U. & Albrektson, A. 1993. Productivity of needles and allocation of growth in young Scots pine trees of different competitive status. Forest Ecology and Management 62, 173-187.
  65. Nilsson, U. & Hällgren, J-E. 1993. Changes in growth allocation owing to competition for light in young fertilized Norway spruce trees. Forest Ecology and Management 62, 157-187.
  66. Nilsson, U. & Gemmel, P. 1993. Changes in growth and allocation of growth in young Pinus sylvestris and Picea abies due to competition. Scandinavian Journal of Forest Research 8, 213-222.
  67. Fries, C. & Nilsson, U. 1990. Development of underplanted Pinus sylvestris in a Betula pubescens shelterwood in northern Sweden. Scandinavian Journal of Forest Research 5, 525-534.