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Torgny Näsholm

Torgny Näsholm
My main topic of interest is plant nitrogen nutrition. Boreal forests are often nitrogen limited and it was assumed this was because of a limitation of production of inorganic nitrogen forms in the cold and acid soils of this biome. Research within my group has contributed to a change in this paradigm as it has shown that plants in general, and forest plants in particular utilise a range of organic nitrogen forms as well. Through developing new methodology for low-invasive monitoring of soil nitrogen dynamics we have also shown that organic nitrogen dominate the soil solution of boreal forest soils. These discoveries have also given a foundation for the development of a new type of nitrogen fertilizers.

Presentation

I am professor in Tree Ecophysiology. I have been editor and associate editor in chief of the journal Tree Physiology since 2010. Part of my research is within the Department of forest ecology and management but part of it is within the Department of forest genetics and plant physiology.

Teaching

I teach at various courses including 1st years course in Tree biology and advanced level courses such as "site productivity".

Research

Ecophysiology of boreal forests is my main topic but some of my studies also include the model plant Arabidopsis thaliana. I focus on mineral nutrition, in particular nitrogen nutrition and interactions between nitrogen, carbon and water. A substantial part of this work is devoted to the role of organic nitrogen compounds for plant nitrogen nutrition and together with colleagues I have developed a series of tools to study soil nitrogen availability and plant nitrogen uptake.

Background

My background is in biology and chemistry and with a focus on plant physiology.

Selected publications

Recent examples:

1.     McMurtrie RE, Näsholm T. 2017. Quantifying the contribution of mass flow to nitrogen acquisition by an individual plant root. New Phytologist doi:10.1111/nph.14927

2.     Oyewole O, Inselsbacher E, Näsholm T, Jämtgård S. 2017. Incorporating mass flow strongly promotes N flux rates in boreal forest soils Soil Biol. Biochem. doi.org/10.1016/j.soilbio.2017.07.021.

3.     Buckley S, Brackin R, Näsholm T, Schmidt S, Jämtgård S. 2017. Improving in situ recovery of soil nitrogen using the microdialysis technique. Soil Biol. Biochem 114: 93-103.

4.     Lim H, Oren R, Linder S, From F, Nordin A, Fahlvik N, Lundmark T, Näsholm T. 2017. Annual climate variation modifies nitrogen induced carbon accumulation of Pinus sylvestris forests. Ecological Applications. doi: 10.1002/eap.1571/pdf.

5.     Ganeteg U, Ahmad I, Jämtgård S, Cambui C, Inselsbacher E, Svennerstam, H, Schmidt S, Näsholm T. 2017. Amino acid transporter mutants of Arabidopsis provides evidence that a non-mycorrhizal plant acquires organic nitrogen from agricultural soil. Plant Cell & Environment 40: 413-423. doi: 10.1111/pce.12881.

6.     Tarvainen L, Näsholm T. 2017. Can adjustments in foliar nitrogen use efficiency reduce drought stress impacts on boreal trees? Tree Physiology (commentary) 37: 415-417. doi:10.1093/treephys/tpx003.

7.     Franklin O, Cambui C, Palmroth S, Oren R & Näsholm T. 2017. The carbon bonus of organic nitrogen enhances nitrogen use efficiency of plants.  Plant Cell & Environment 40: 25-35. doi: 10.1111/pce.12772

8.     Tor-ngern P, Oren R, Oishi AC, Uebelherr JM, Parlmroth S, Tarvainen L, Ottosson-Löfvenius M, Linder S, Domec J-C, Näsholm T. 2017. Ecophysiological variation of transpiration of pine forests: synthesis of new and published results. Ecological Applications 27: 118-133. DOI: 10.1002/eap.1423

9.     Oyewole O, Jämtgård S, Gruffman L, Inselsbacher E, Näsholm T. 2016. Soil diffusive fluxes constitute the bottleneck to tree nitrogen nutrition in a Scots pine forest. Plant and Soil DOI 10.1007/s11104-015-2680-5.

10.  Brackin R, Näsholm T, Robinson N, Guillou S, Vinall K, Lakshmanan P, Schmidt S, Inselsbacher E. 2015. Nitrogen fluxes at the root-soil interface show a mismatch of nitrogen fertilizer supply and sugarcane root uptake capacity. Scientific Reports, 5:15727

11.  Henriksson N, Tarvainen L, Lim H, Tor-Ngern P, Palmroth S, Oren R, Marshall J, Näsholm T. 2015. Stem compression reversibly reduces phloem transport in Pinus sylvestris trees. Tree Physiology 35: 1075-1085. doi: 10.1093/treephys/tpv078.

12.  Wullschleger SW, Breen AM Iversen CM, Olson MS, Näsholm T, Ganeteg U, Wallenstein MD, Weston DJ. 2015. Genomics in a changing Arctic: Critical questions await the molecular ecologist. Molecular Ecology 24: 2301-2309.

13.  Lim H, Oren R, Palmroth S, Tor-ngern P, Mörling T, Näsholm T, Lundmark T, Helmisaari H-S, Leppälammi-Kujansuu J Linder S. 2015. Inter-annual variability of precipitation constrains the production response of boreal Pinus sylvestris to nitrogen fertilization. Forest Ecology and Management. 348: 31-45.

14.  Franklin O, Palmroth S, Näsholm T. 2014. How eco-evolutionary principles may guide tree breeding and tree biotechnology for enhanced production. Tree Physiology 34: 1149-1166.

15.  Näsholm T, Palmroth S, Ganeteg U, Moshelion M, Hurry V, Franklin O 2014. Genetics of superior growth traits in trees are being mapped but will the faster-growing risk-takers make it in the wild? Tree Physiology 34: 1141-1148.

16.  Franklin O, Näsholm T, Högberg P, Högberg MN. 2014. Forests trapped in nitrogen limitation – an ecological market perspective on ectomycorrhizal symbiosis. New Phytologist 203: 657-666.

17.  Lonhienne TGA, Trusov Y, Young A, Rentsch D, Näsholm T, Schmidt S, and Paungfoo-Lonhienne C. 2014. The effect of protein on root morphology and plant biomass allocation. Scientific Reports 4:5055.

18.  Inselsbacher E, Oyewole O, Näsholm T. 2014. Early season dynamics of soil nitrogen fluxes in fertilized and unfertilized boreal forests.  Soil Biol. Biochem. 74: 167-176.

19.  Gruffman L, Jämtgård S, Näsholm T. 2014. Plant nitrogen status and co-occurrence of organic- and inorganic nitrogen sources influence root uptake by Scots pine seedlings. Tree Physiology 34: 205-213.

20.  Oyewole O, Inselsbacher E, Näsholm T. 2014. Direct estimation of mass flow and diffusion of nitrogen compounds in solution and soil. New Phytologist 201: 1056-1064.

21.  Gruffman L, Palmroth S, Näsholm T. 2013. Organic nitrogen uptake by Scots pine seedlings is independent of current carbohydrate supply. Tree Physiology 33: 590-600.

22.  Wei L, Chen C, Xu Z, Näsholm T. 2013. Direct uptake and rapid decrease of organic nitrogen by Wollemia nobilis. Biol Fertil Soils 49: 1247-1252.

23.  Kuhlmann F, Opitz SEW, Inselsbacher E, Ganeteg U, Näsholm T, Ninkovic V. 2013. Exploring the Nitrogen Ingestion of Aphids — a New Method Using Electrical Penetration Graph and 15N Labelling. PLoS ONE 8: e83085

24.  Näsholm T, Högberg P, Franklin O, Metcalfe D, Keel SG, Campbell CD, Hurry V, Linder S, Högberg MN. 2013. Are ectomycorrhizal fungi alleviating of aggravating N limitation of tree growth in boreal forests? New Phytologist, 198: 214-221.

25.  Inselsbacher E, Näsholm T. 2012. The belowground perspective of forest plants – soil provides mainly organic N for plants and mycorrizal fungi. New Phytologist, 195: 329-334. (Rapid report) doi: 10.1111/j.1469-8137.2012.04169.x.

26.  Gruffman L, Nordin A, Ishida T, and Näsholm T. 2012. Cultivation of Norway spruce and Scots pine on organic nitrogen improves seedling morphology and field performance. Forest Ecology & Management, 276: 118–124.

27.  Inselsbacher E, Näsholm T. 2012. Effects of soil temperature on diffusive fluxes of plant-available nitrogen in soil. Plant and Soil, 354: 251-257.

28.  Cambui CA, Svennerstam H, Gruffman L, Nordin A, Ganeteg U, Näsholm, T. 2011. Patterns of plant biomass partitioning depend on nitrogen source. PLoS ONE doi:10.1371/journal.pone.0019211.

29.  Inselsbacher E, Öhlund J, Jämtgård S, Huss-Danell K, Näsholm T. 2011. The potential of microdialysis to monitor organic and inorganic nitrogen compounds in soil. Soil Biol. Biochem. 43: 1321-1332.

30.  Svennerstam H, Jämtgård S, Huss-Danell K, Näsholm T, Ganeteg U. 2011. Transporters in Arabidopsis roots enabling uptake of amino acids at field relevant concentrations. New Phytologist 191: 459-467.

31.  Gärdenäs AI, Ågren GI, Bird JA, Clarholm M, Hallin S, Ineson P, Kätterer K, 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 Biol. Biochem. 43: 702-717.

32.  Jämtgård S, Näsholm T, Huss-Danell K. 2010. Nitrogen compounds in soil solutions of agricultural land. Soil Biol. Biochem. 42: 2325-2330.

33.  Paungfoo-Lonhienne C, Rentsch D, Robatzek S, Webb RI, Sagulenko E, Näsholm T, Schmidt S, Lonhienne TGA. 2010. Turning the Table: Plants Consume Microbes as a Source of Nutrients. PLoS One 5:1-11.

 


Contact
Professor at the Department of Forest Ecology and Management; Ecophysiology Unit
Telephone: +46-90-786 8205
Postal address:
SLU,
Skogens ekologi och skötsel
901 83 Umeå
Visiting address: Skogsmarksgränd 17, Umeå