I grew up in a small farm in Tönnånger, a village in southern Hälsingland. My parents were interested in natural science and could answer most of my questions about nature. At school, I got an ambitious teacher who gave the pupils a group assignment to write down all birds during the spring term. This was the start of my large bird interest, which was then extended to plants and butterflies.
After the elementary school, I got the opportunity to go to the higher education in Söderhamn. After graduating in 1961, I came to Uppsala University for studies in zoology, botany and limnology. I conducted my Master´s work in entomology about hibernating arthropods in nest boxes.
After my bachelor degree, I got a job 1967 as an assistant in a governmental investigation about natural resources in Stockholm. There I compiled data on mercury concentrations in birds and fish. The work contributed to measures that reduced mercury use in agriculture and the pulp industry.
I started my postgraduate education in entomology at Uppsala University in 1968 together with two other doctoral students. We were colleagues in the Swedish part of the International Biological Program (IBP). The IBP program had its active phase during 1964-1974 with the goal of "learning how to produce more food for a growing population”. One piece of the puzzle was to understand the production potential of different ecosystems. As part of this, we determined the energy flow through plants and animals in an abandoned grassland (Spikbole) and a deciduous forest (Andersby ängsbackar), both sites in Uppland, Sweden. We studied both leaf-eating insects and soil fauna, but my focus was the grassland soil fauna, which was included in my PhD thesis.
IBP inspired parts of the research community for new achievements in systems ecology (“big ecology”), and such an initiative was the "Swedish Coniferous Forest Project", which took place during 1973-1980 at Jädraås. My contribution to the project was to quantify abundance, biomass and production of various soil animals. Up until then, zoologists, microbiologists and soil scientists had seldom worked together, but in this SWECON project, we found that such a cooperation with a common goal was necessary for progress. The results were summarized in the "SWECON volume" (Persson 1980).
Nitrogen (N) turnover in soil is largely dependent on the interaction between soil organisms, and I did several experiments to determine the role of soil fauna. One conclusion was that soil animals contribute much more to N mineralization than to the carbon (C) mineralization. In 1994, I was appointed professor in soil biology with focus on forest soil processes at SLU.
Since 1970, many liming, fertilization, irrigation and burning experiments were laid out with good statistical design. I was interested in how these field trials affected C and N pools, C and N mineralization and the abundance and biomass of various soil fauna groups. The studies of forest liming resulted in the conclusion that the benefit (high pH, low aluminium levels) often could not compensate for the drawbacks of side effects (C loss, nitrate leaching). These results led to lower subsidies for forest liming. Some of the experiments were also be used by my PhD students for their doctoral theses.
We also examined C and N turnover in a number of EU projects (Niphys, Canif, Forcast and Carbo-Europe IP) with sites in a gradient from Italy to Sweden. The Swedish LUSTRA project was a Swedish variant of the above-mentioned EU projects, and in this project we determined the efficiency of added N to tree and soil C in pine and spruce forests.
In 2008 I was formerly retired. During 2008-2015, I coordinated a research program on stump harvesting. The program showed that from a climatic viewpoint, bioenergy from stumps is a better source of energy than fossil fuels. Emissions of carbon dioxide, methane and nitrous oxide decreased after stump harvesting. However, insects dependent on dead wood could be adversely affected, but the impact was almost negligible if the extraction of stumps was limited to 10% of the total clear-cut area in a whole landscape.
In summary, my research has mostly concerned environmental issues and societal problems (population growth and food shortage, acidification and forest damage, forestry and biodiversity, and how to counteract climate change). As a retired professor, I am now finishing manuscripts about long-term field experiments concerning soil organisms and ecosystem processes.
I have supervised 10 PhD students and 2 licentiates.
Biodiversity and soil foodwebs
Hyvönen, R., Andersson, S., Clarholm, M & Persson, T. 1994. Effects of lumbricids and enchytraeids on nematodes in limed coniferous mor humus. -Biol. Fertil. Soils. 17:200-205.
Bengtsson, J., Zheng, D.W., Ågren, G.I. & Persson, T. (1995). Food webs in soil: an interface between population and ecosystem ecology. -In: Jones, C.G. & Lawton, J.H. (eds) Linking species and ecosystems, pp. 159-165. Chapman & Hall, New York.
Hyvönen R, Persson T (1996) Effects of fungivorous and predatory arthropods on nematodes and tardigrades in microcosms with coniferous forest soil. Biol. Fertil. Soils 21:121-127.
Huhta V, Persson T, Setälä H (1998) Functional implications of soil fauna diversity in boreal forests. Applied Soil Ecology 10:277-288.
Lenoir L, Bengtsson J, Persson T (1999) Effects of coniferous resin on fungal biomass and mineralisation processes in wood ant nest materials. Biology and Fertility of Soils 30:251-257.
Lenoir L, Persson T, Bengtsson J (2001) Wood ant nests as potential hot spots for carbon and nitrogen mineralisation. Biology and Fertility of Soils 34:235-240
Lenoir L, Bengtsson J, Persson T (2003). Effects of conifer resin on soil fauna in potential wood-ant nest materials at different moisture levels. Pedobiologia 47:19-25.
Lenoir L, Bengtsson J, Persson T (2003). Effects of Formica ants on soil fauna – results from a short-term exclusion and a long-term natural experiment. Oecologia 134:423-430.
Lenoir L, Persson T, Bengtsson J, Wallander H, Wirén A (2007) Bottom-up or top-down control in forest soil microcosms? Effects of soil fauna on fungal biomass and C/N mineralisation. Biology and Fertility of Soils 43:281-294.
Remén C, Fransson P, Persson T (2010). Population responses of oribatids and enchytraeids to ectomycorrhizal and saprotrophic fungi in plant – soil microcosms. Soil Biology and Biochemistry 42:978-985.
Mikusinska A, Persson T, Taylor AFS, Ekblad A (2013) Response of ectomycorrhizal extramatrical mycelium production and isotopic composition to in-growth bag size and soil fauna. Soil Biology and Biochemistry 66:154-162.
Bioturbation/ecosystem engineers
Taylor AR, Lenoir L, Vegerfors B, Persson T 2018. Ant and earthworm bioturbation in cold-temperate ecosystems. Ecosystems 22:981-994.
Burning effects
Malmström A., Persson T., Ahlström K. 2008. Effects of fire intensity on survival and recovery of soil microarthropods after a clearcut burning Canadian Journal of Forest Research 38:2465-2475.
Malmström A, Persson T, Ahlström K, Gongalsky KB, Bengtsson J (2009) Dynamics of soil meso- and macrofauna during a 5-year period after clear-cut burning in a boreal forest. Applied Soil Ecology 43:61-74.
Gongalsky KB, Malmström A, Zaitsev AS, Shakab, SV, Bengtsson J, Persson T (2012) Do burned areas recover from inside? An experiment with soil fauna in a heterogeneous landscape. Applied Soil Ecology 59:73-86.
Gongalsky KB, Persson T (2013) Recovery of soil macrofauna after wildfires in boreal forests. Soil Biology and Biochemistry 57:182-191.
Zaitsev AS, Gongalsky KB, Persson T, Bengtsson J (2014). Connectivity of litter islands remaining after a fire and unburnt forest determines the recovery of soil fauna. Applied Soil Ecology 83:101-108.
Zaitsev AS, Gongalsky KB, Malmström A, Persson T, Bengtsson J. 2016. Why are forest fires generally neglected in soil fauna research? A mini-review. Applied Soil Ecology 98: 261-271.
C and N turnover
Persson, T. & Wirén, A. 1995. Nitrogen mineralization and potential nitrification at different depths in acid forest soils. -Plant and Soil 168-169:55-65.
Nohrstedt H-Ö, Sikström U, Ring E, Näsholm T, Högberg P, Persson T (1996) Nitrate in soil water in three Norway spruce stands in southwest Sweden as related to N-deposition and soil, stand, and foliage properties. Can. J. For. Res. 26:836-848.
Rudebeck A, Persson T (1998). Nitrification in organic and mineral soil layers in coniferous forests in response to acidity. Environmental Pollution 102:377-383.
Sjöberg RM, Persson T (1998). Turnover of carbon and nitrogen in coniferous mor humus of different N-status and under different 15NH4-N application rate. Environmental Pollution 102:385-393.
Persson T, Breland TA, Seyferth U, Lomander A, Kätterer T, Henriksen TM, Andrén O (1999) Carbon and nitrogen turnover in forest and arable soil in relation to substrate quality, temperature and moisture. In: Jansson P-E, Persson T, Kätterer T (eds) Nitrogen processes in arable and forest soils in the Nordic countries - Field-scale modelling and experiments, TemaNord 1999:560, pp. 131-152.
Persson T, Karlsson PS, Seyferth U, Sjöberg RM, Rudebeck A (2000) Carbon mineralisation in European forest soils. In: Schulze E-D (ed) Carbon and nitrogen cycling in European forest ecosystems, Springer-Verlag, Ecol Stud 142:257-275
Persson T, Rudebeck A, Jussy JH, Colin-Belgrand M, Priemé A, Dambrine E, Karlsson PS, Sjöberg RM (2000) Soil nitrogen turnover - mineralisation, nitrification and denitrification in European forest soils. In: Schulze E-D (ed) Carbon and nitrogen cycling in European forest ecosystems, Springer-Verlag, Ecol Stud 142:297-331
Schulze E-D, Högberg P, van Oene H, Persson T, Harrison AF, Read D, Kjøller A, Matteucci G (2000) Interactions between the carbon and nitrogen cycle and the role of biodiversity: A synopsis of a study along a north-south transect through Europe. In: Schulze E-D (ed) Carbon and nitrogen cycling in European forest ecosystems, Springer-Verlag, Ecol Stud 142:468-491
Öquist MG, Nilsson M, Sörensson F, Kasimir-Klemedtsson Å, Persson T, Weslien P, Klemedtsson L (2004) Nitrous oxide production in a forest soil at low temperatures – processes and environmental controls. FEMS Microbiology Ecology 49:371-378.
Sjöberg G, Nilsson SI, Persson T, Karlsson P (2004) Degradation of hemicellulose, cellulose and lignin in decomposing spruce needle litter in relation to N. Soil Biol. Biochem. 36:1761-1768.
Kutsch WL, Persson T, Schrumpf M, Moyano FE, Mund M, Andersson S, Schulze E-D (2010) Heterotrophic soil respiration and soil carbon dynamics in the deciduous Hainich forest obtained by three approaches. Biogeochemistry 100:167-183.
Gärdenäs AI, Ågren GI, Bird JA, Clarholm M, Hallin S, Ineson P, Kätterer T, Knicker H, Nilsson SI, Näsholm T, Ogle S, Paustian K, Persson T, Stendahl J (2011). Knowledge gaps in soil carbon and nitrogen interactions - From molecular to global scale. Soil Biology and Biochemistry 43:702-717.
Olsson, B.A., Hansson, K., Persson, T., Beuker, E., Helmisaari, H.-S. (2012). Heterotrophic respiration and nitrogen mineralisation in soils of Norway spruce, Scots pine and silver birch stands in contrasting climates. Forest Ecology and Management 269:197-205.
Schrumpf M, Kaiser K, Guggenberger G, Persson T, Kögel-Knabner I, Schulze E-D (2013) Storage and stability of organic carbon in soils as related to depth, occlusion within aggregates, and attachment to minerals. Biogeosciences 10:1675-1691.
Hansson K, Fröberg M, Helmisaari H-S, Kleja DB, Olsson BA, Olsson M, Persson T (2013) Carbon and nitrogen pools and fluxes above and below ground in spruce, pine and birch stands in southern Sweden. Forest Ecology and Management 309:28-35.
Clear-cutting, logging residues and tree girdling
Bengtsson J, Persson T, Lundkvist H 1997. Long-term effects of logging residue addition and removal on macroarthropods and enchytraeids. Journal of Applied Ecology 34:1014-1022.
Remén C, Persson T, Finlay R, Ahlström K (2008). Responses of oribatid mites to tree girdling and nutrient addition in boreal coniferous forests. Soil Biology & Biochemistry 40:2881-2890.
Malmström A, Persson T (2011) Responses of Collembola and Protura to tree girdling – some support for ectomycorrhizal feeding. Soil Organisms 83:279-285.
Bergholm J, Olsson B.A., Vegerfors B, Persson T (2015) Nitrogen fluxes after clear-cutting. Ground vegetation uptake and stump/root immobilisation reduce N leaching after experimental liming, acidification and N fertilisation. Forest Ecology and Management 342: 64–75.
Clarke, N., Gundersen, P., Jönsson-Belyazid, U., Kjønaas, J., Persson, T., Sigurdsson, B.D., Stupak, I., Vesterdal, L. 2015. Influence of different tree-harvesting intensities on forest soil carbon stocks in boreal and northern temperate forest ecosystems. Forest Ecology and Management 351: 9-19.
Climate change
Hyvönen R, Ågren GI, Linder S, Persson T, Cotrufo MF, Ekblad A, Freeman M, Grelle A, Janssens IA, Jarvis PG, Kellomäki S, Lindroth A, Loustau D, Lundmark T, Norby RJ, Oren R, Pilegaard K, Ryan MG, Sigurdsson BD, Strömgren M, van Oijen M, Wallin G (2007). The likely impact of elevated [CO2], nitrogen deposition, increased temperature and management on carbon sequestration in temperate and boreal forest ecosystems: a literature review. New Phytologist 173:463–480.
Wetterstedt JÅM, Persson T, Ågren GI (2010) Temperature sensitivity and substrate quality in soil organic matter decomposition. Global Change Biology 16:1806-1819.
Forest fertilization and N deposition
Lohm, U., Lundkvist, H., Persson, T. & Wirén, A. 1977. Effects of nitrogen fertilization on the abundance of enchytraeids and microarthropods in Scots pine forests. -Stud. For. Suec. 140:1-23.
Näsholm T, Persson T (2000) Hur påverkas mark och växter av kvävenedfall? – en syntes. In: Bertills U, Näsholm T (eds) Effekter av kvävenedfall på skogsekosystem, Naturvårdsverket Rapport 5066:121-130
Lindberg N, Persson T (2004). Effects of long-term nutrient fertilisation and irrigation on the microarthropod community in a boreal Norway spruce stand. Forest Ecology and Management 188:125-135.
Hyvönen R, Persson T, Andersson S, Olsson B, Ågren GI, Linder S. 2008. Impact of long-term nitrogen addition on carbon stocks in trees and soils in northern Europe. Biogeochemistry 89:121-137.
Irrigation and drought
Lindberg N, Bengtsson J, Persson T (2002). Effects of experimental irrigation and drought on the composition and diversity of soil fauna in a coniferous stand. Journal of Applied Ecology 39:924-936.
Liming, acidification and ash application
Persson, T. 1988. Effects of liming on the soil fauna in forests. A literature review. -National Swedish Environmental Protection Board Report 3418:1-92.
Persson, T., Lundkvist, H., Wirén, A., Hyvönen, R. & Wessén, B. 1989. Effects of acidification and liming on carbon and nitrogen mineralization and soil organisms in mor humus. -Water, Air, and Soil Pollut. 45:77-96.
Persson, T. & Wirén, A. 1989. Microbial activity in forest soils in relation to acid/base and carbon/nitrogen status. -Medd. Nor. inst. skogforsk. 42:83-94.
Hyvönen, R. & Persson, T. 1990. Effects of acidification and liming on feeding groups of nematodes in coniferous forest soils. -Biol. Fertil. Soils 9:205-210.
Persson, T., Wirén, A. & Andersson, S. 1990/91. Effects of liming on carbon and nitrogen mineralization in coniferous forests. -Water, Air, and Soil Pollut. 54:351-364.
Persson, T. & Wirén, A. 1993. Effects of experimental acidification on C and N mineralization in forest soils. -Agric. Ecosyst. Environ. 47:159-174.
Persson T, Rudebeck A & Wirén A 1995. Pools and fluxes of carbon and nitrogen in 40-year-old forest liming experiments in southern Sweden. -Water, Air and Soil Pollution 85:901-906.
Persson T, Wirén A (1996) Effekter av skogsmarkskalkning på kväveomsättningen. Naturvårdsverket Rapport 4559:70-91.
Persson T, Andersson S, Chalupsky, J, Clarholm M, Gahne, B, Hyvönen, R, Lundkvist H, Palmborg C, Rundgren S, Wirén A (1996) Effekter av skogsmarkskalkning på markorganismerna. Naturvårdsverket Rapport 4559:160-182.
Nilsson SI, Andersson S, Valeur I, Persson T, Bergholm J, Wirén A (2001) Influence of dolomite lime on leaching and storage of C, N and S in a spodosol under Norway spruce (Picea abies (L.) Karst.). Forest Ecology and Management 146:55-73.
Persson T (2002) Long-term effects of forest liming on Enchytraeidae and Lumbricidae in a spruce stand in southern Sweden. Natura Jutlandica, Occasional Papers 2:96-100.
Rosenberg O, Persson T, Högbom L, Jacobson S (2010). Effect of wood-ash application on potential carbon and nitrogen mineralisation at two forest sites with different tree species, climate and N status. Forest Ecology and Management 260:511-518.
Oulehle F, Evans CD, Hofmeister J, Krejci R, Tahovska K, Persson T, Cudlin P, Hruska J (2011) Major changes in forest carbon and nitrogen cycling caused by declining sulphur deposition. Global Change Biology 17:3115-3129.
Role of soil fauna for C and N dynamics
Persson, T. & Lohm, U. 1977. Energetical significance of the annelids and arthropods in a Swedish grassland soil. -Ecol. Bull. (Stockholm) 23:1-211.
Persson, T., Bååth, E., Clarholm, M., Lundkvist, H., Söderström, B.E. & Sohlenius, B. 1980. Trophic structure, biomass dynamics and carbon metabolism of soil organisms in a Scots pine forest. -Ecol. Bull. (Stockholm) 32:419-459.
Persson, T. 1983. Influence of soil animals on nitrogen mineralisation in a northern Scots pine forest. -In: Lebrun, P. et al. (eds.) New trends in soil biology, Proc. 8th Int. Coll. Soil Zool., pp. 117-126. Ottignies-Louvain-la-Neuve: Dieu-Brichart.
Axelsson, B., Lohm, U. & Persson, T. 1984. Enchytraeids, lumbricids and soil arthropods in a northern deciduous woodland - a quantitative study. -Holarct. Ecol. 7:91-103.
Persson, T. 1989. Role of soil animals in C and N mineralization. -Plant and Soil 115:241-245.
Stump harvesting
Persson, T., Lenoir, L., Vegerfors, B. (2013) Which macroarthropods prefer tree stumps over soil and litter substrates? Forest Ecology and Management 290:30-39.
Kaarakka L, Hyvönen R, Strömgren M, Palviainen, M, Persson T, Olsson BA, Launonen E, Vegerfors B, Helmisaari H-S. 2016. Carbon and nitrogen pools and mineralization rates in boreal forest soil after stump harvesting. Forest Ecology and Management 377: 61-70.
Persson T, Lenoir L, Vegerfors B 2017. Long-term effects of stump harvesting and site preparation on pools and fluxes of soil carbon and nitrogen in central Sweden. Scand J For Res 32:222-229.
Persson T, Egnell G, Lithell CH (eds.) (2017). Stump harvesting – Impact on climate and environment. IEA Bioenergy: Task 43 TR 2017: 02, 111 pp. (Populärvetenskaplig rapport på engelska)
Persson T, Egnell G 2018. Stump harvesting for bioenergy: A review of climatic and environmental impacts in northern Europe and America. WIREs Energy and Environment 2018;e307, 26 pp. https://doi.org/10.1002/wene.307
Sundqvist E, Vestin P, Crill P, Persson T, Lindroth A (2014). Short-term effects of thinning, clear-cutting and stump harvesting on methane exchange in a boreal forest. Biogeosciences 11: 6095-6105.
Editor for scientific volumes
Lohm U, Persson T (eds.) (1977). Soil organisms as components of ecosystems. -Ecol. Bull. (Stockholm), 614 pp.
Persson T (ed.) (1980). Structure and function of northern coniferous forests - an ecosystem study. -Ecol. Bull. (Stockholm) 32, 609 pp.
Staaf H, Persson T, Bertills U (eds) 1996. Skogsmarkskalkning. Resultat och slutsatser från Naturvårdsverkets försöksverksamhet. Naturvårdsverket Rapport 4559, 290 pp. (in Swedish).
Jansson P-E, Persson T, Kätterer T (eds.) (1999). Nitrogen processes in arable and forest soils in the Nordic countries - Field-scale modelling and experiments, TemaNord 1999:560, 203 pp.
Persson T, Nilsson L-O (eds.)(2001) Skogabyförsöket - Effekter av långvarig kväve- och svaveltillförsel till ett skogsekosystem. Naturvårdsverket, Rapport 5173, 220 sid. (In Swedish)
Palmér CH, Lithell C, Persson T (eds.) (2016). Stubbskörd – hur påverkas klimat och miljö? 99 pp. (Popular science report in Swedish)
Persson T, Egnell G, Lithell CH (eds.) (2017). Stump harvesting – Impact on climate and environment. IEA Bioenergy: Task 43 TR 2017: 02, 111 pp. (Popular science report in English)