University of Helsinki
Forest biomass harvesting and biogeochemistry
Various funders, 2007-
The main aim of the research is to understand the significance of biomass harvesting, especially logging residue and stump harvesting, to carbon and nutrient pools and fluxes and nutrient availability in forests of different sites, to explain the observed changes, and to predict their development in different bioenergy harvesting scenarios.
Some projects
Comparing the impact of continuous cover forest management and rotation forest management on long-term soil carbon storage
Ph.D thesis of Eva Roth, started in 2020 (funded by the Finnish Natural Resources Research Foundation)
(Supervisors Kristiina Karhu, H-S Helmisaari, Eeva-Stiina Tuittila)
Longevity of soil changes and long-term ecosystem recovery from chemical and physical load, H-S. Helmisaari, Marjo Palviainen, Lilli Kaarakka, Aino Smolander (Metla) & Antti-Jussi Lindroos (Metla), research project funded by the Nessling foundation 2013-2017.
Background
Stump harvesting followed by site preparation is a practice that affects forest soil structure and ecosystem carbon and nutrient cycling while logging residue harvesting for forest energy involves nutrient and organic matter removal leading into decreased tree growth in thinning stands, especially (Helmisaari et al. 2011). Both practices affect soil processes and soil as a habitat for biota. The effects of stump harvesting are not completely known and there is very little information on the long-term impacts.
Aims
The aim was to determine the long-term physical and chemical changes in forest soils as well as the ecosystem recovery from stump harvesting.
Implementation
The impacts of bioenergy harvesting were studied on different sites in southern Finland. We determined soil organic layer and mineral soil physical and chemical properties and processes (carbon and nitrogen mineralisation, soil respiration) in relation to soil disturbance and time since harvesting.
Cooperation
Dr. Bengt Olsson, Dr. Riitta Hyvönen-Olsson & Dr. Monika Strömgren, Swedish University of Agricultural Sciences
Results
See Lilli Kaarakka´s Ph. D thesis and publications there
Artikkeli Kantojen korjuu pienentää maaperän hiilivarastoa
Some other publications
Titus, B., Brown, K., Helmisaari, H-S., Vanguelova, E., Stupak, I., Evans, A., Clarke, N., Guidi, C., Bruckman, V.J., Varnagiryte-Kabasinskiene, I., Armolaitis, K., de Vries, W., Hirai, K., Kaarakka, L., Hogg, K., Reece, P. 2021. Sustainable forest biomass: a review of current residue harvesting guidelines. Energy, Sustainability and Society T (2021) 11:10
Kaarakka, L., Vaittinen, J., Marjanen, M., Hellsten, S., Kukkola, M., Saarsalmi, A., Palviainen, M. and Helmisaari, H-S. 2018. Stump harvesting in Picea abies stands: soil surface disturban e and biomass distribution of the harvested stumps and roots. Forest Ecology and Management 425: 27-34.
Toivio, J., Helmisaari, H-S., Palviainen, M., Lindeman, H., Ala-Ilomäki, J., Sirén, M. & Uusitalo, J. 2017. Effects of timber skidding on physical properties of forest soils in southern Finland (abstract, page 16). Pro Terra 71:16.
Kaarakka, L., Hyvönen, R., Strömgren, M., Palviainen, M., Persson, T., Olsson, B.A., Launonen, E., Vegerfors, B. & Helmisaari, H-S. 2016. Carbon and nitrogen pools and mineralization rates in boreal forest soil after stump harvesting. (summary). Forest Ecology and Management 377: 61-70.
Hyvönen, R., Kaarakka, L., Leppälammi-Kujansuu, J., Olsson, B.A., Palviainen, M., Vegerfors-Persson, B. & Helmisaari, H-S. 2016. Effects of stump harvesting on soil C and N stocks and vegetation 8–13 years after clear-cutting. (summary). Forest Ecology and Management 371: 23-32.
Helmisaari, H-S., Kaarakka, L. & Olsson, B. A. 2014. Increased utilization of different tree parts for energy purposes in the Nordic countries. Scandinavian Journal of Forest Research 29(4): 312-322. (open access)
Kaarakka, L., Tamminen, P., Saarsalmi, A., Kukkola, M., Helmisaari, H-S. & Burton, A. J. 2014. Effects of repeated whole-tree harvesting on soil properties and tree growth in a Norway spruce (Picea abies (L.) Karst.) stand. (summary) Forest Ecology and Management 313: 180-187.
Helmisaari, H-S. & Kaarakka, L. 2013. Nutrient Management for Sustainable Production of Energy Biomass in Boreal Forests. In: Forest BioEnergy Production: Management, Carbon Sequestration and Adaptation. Kellomäki, S., Kilpeläinen, A. & Alam, A. (eds.). New York: Springer, p. 81-94.
Long-term Impacts of Forest Residue Harvest on Biogeochemical Cycles and Stem-wood Production (pdf). Keynote- presentation in a conference “Growing the Bioeconomy: Social, Environmental and Economic Implications”, October 2-5, 2012, Banff, Alberta, Canada
Hellsten, S., Helmisaari, H., Melin, Y., Jens Peter, S., Kaakinen, S., Kukkola, M., Saarsalmi, A., Petersson, H. & Akselsson, C. 2013. Nutrient concentrations in stumps and coarse roots of Norway spruce, Scots pine and silver birch in Sweden, Finland and Denmark. Forest Ecology and Management 290, s. 40-48.
Tamminen, P., Saarsalmi, A., Smolander, A., Kukkola, M. & Helmisaari, H-S. 2012. Effects of logging residue harvest in thinnings on amounts of soil carbon and nutrients in Scots pine and Norway spruce stands. Forest Ecology and Management 263: 31-38.
Helmisaari, H-S., Holt Hanssen, K., Jacobson, S., Kukkola, M., Luiro, J., Saarsalmi, A., Tamminen, P. & Tveite, B. 2011. Logging residue removal after thinning in Nordic boreal forests: Long-term impact on tree growth. Forest Ecology and Management 261: 1919-1927.
Helmisaari, H-S., Kukkola, M., Luiro, J., Saarsalmi, A., Smolander, A. & Tamminen, P. 2009. Hakkuutähteiden korjuu – muuttuuko typen saatavuus? (pdf) Metsätieteen aikakauskirja 2009(1): 57-62.
Past events
Workshop W6.1 in the EUROSOIL congress: “Forest bioenergy and soil sustainability”, conveners H-S. Helmisaari & Elena Vanguelova, UK. Proceedings.
Earlier projects
Empirical assessment of the effects of biomass removal on nutrient availability. A sub study (H-S. Helmisaari & Jukka Luiro) within the project “Economic-ecological optimization of timber and bioenergy production and sequestration of carbon in Norway spruce stands” (Olli Tahvonen et al., Academy of Finland 2009-2012).
Impacts of Forest Floor Manipulations and the Problem of Post Harvest Residue Removal for Biofuels, a student exchange project, prof. John Dighton, Rutgers University, USA & H-S. Helmisaari; funded by NSF (National Science Foundation) in 2009-2011.
Biomass harvesting for energy – latest scientific knowledge on the ecological impacts in Nordic forests
Research seminar, Wednesday 5th April 2017 at 9–16, Viikki Infocenter, Auditorium 2
More intense biomass harvesting, including residues and stumps, has become a common practice in Finnish forestry – but what are the ecological impacts? How is the soil affected, is there a sustainable quota in terms of harvesting of different biomass compartments, and what happens to tree growth and carbon balance? These questions among others are addressed 5.4. in Helsinki at a seminar organized by the forest soil science researchers of the University of Helsinki. The recent results from the project “Soil changes and long-term ecosystem recovery from chemical and physical load” supported by Maj and Tor Nessling foundation will be presented along with the latest research results from the Nordic region. The seminar will be organized in English and everyone is welcome to attend.
Program (Also as pdf here: Final program 5.4.2017)
9.00 – 9.10 Opening; Prof. Heljä-Sisko Helmisaari, University of Helsinki
9.10 – 10.00 What is the highest sustainable level of harvesting slash and stumps for energy in Sweden? Summary of Swedish research on the environmental impacts of forest energy; Assoc. prof. Bengt Olsson, Swedish University of Agricultural Sciences
10.00 – 10.40 Birches and alders as short-rotation species for biomass production – results from long-term research in Estonia; Prof. Veiko Uri, Estonian University of Life Sciences
10.40 – 11.10 Forest biomass use for energy – present situation and future trends; Dr. Johanna Routa, Natural Resources Institute Finland
11.10 – 12.20 Lunch break (own cost)
12.20 – 12.50 Stump harvesting, surface disturbance and time – changes in soil C and N dynamics; M.Sc Lilli Kaarakka, University of Helsinki
12.50 – 13.20 Logging residue harvest on mineral soils: Effects on soil properties and tree growth; Doc. Aino Smolander, Natural Resources Institute Finland
13.20 – 13.50 Tree biomass components as nutrient sources – nutrient balances and sustainability; Doc. Marjo Palviainen, University of Helsinki
13.50 – 14.10 Biomass harvesting for energy in peatland forests: effects on site nutrient pools; Prof. Raija Laiho, Natural Resources Institute Finland
14.10 – 14.30 Coffee (served)
14.30 – 14.50 Do logging residue piles trigger extra decomposition of soil organic matter? Dr. Paavo Ojanen, University of Helsinki
14.50 – 15.20 Effects of stump and residue harvesting on the carbon balance and climate impact of forests; Prof. Jari Liski, Finnish Meteorological Institute
15.20 – 15.50 Forest bioenergy for climate mitigation – carbon rules but do we understand other climate agents; Dr. Tuomo Kalliokoski, University of Helsinki
15.50 – 16.00 Final words
