Duration: 2009-2012
Keywords: carbon, forest soil, litter, nutrients, organic matter, roots
Research Programme: Functioning of forest ecosystems and use of forest resources in changing climate
Over two thirds of the carbon in land ecosystems is belowground, mostly in forest soils (peatlands and upland soils). According to climate predictions, exceptional weather phenomena (e.g.. drought during growing season, storms) will increase in Europe and affect forest carbon balances. Nutrient and carbon balances are closely related, and are affected by the same processes, even if the quantity and quality of the effects may differ.
Limited understanding of fine root turnover time is a key constraint in quantifying terrestrial carbon and nutrient balances and predicting the impacts of global environmental change. Especially, fine root and rhizome longevity, and longevity of their structural carbon, is not well understood or determined.
The aim of this project is to increase understanding on the growth rate and longevity of fine roots of different tree species and understorey, and how it is related to environmental factors. For finding out the relation of fine root longevity to environmental factors, this research will be done on selected sites on a climate gradient from southern Estonia to northern Finland , and on sites varying in their soil fertility.
Especially, we aim to:
We determine tree and understorey fine root longevity by minirhizotrone research in Norway spruce, Scots pine and silver birch stands in northern and southern Finland . With this techniques, fine roots are filmed with a special digital camera which is moved in plexiglass tubes placed horisontally and vertically in soil. In southern Finland the images have been taken since summer 2008. In northern Finland the images were taken at monthly intervals (altogether 12 sessions) during the growing seasons 2004, 2005, 2006 and 2008. The lengths, diameters and status (new, living, dead, disappeared) of Norway spruce and understorey (mainly shrub) fine roots were recorded, and statistical analyses carried out. For estimating the fine-root longevity of either tree or understorey vegetation roots, both Kaplan-Meier and Weibull distribution analyses were compared. Several manuscripts are under preparation.
Radiocarbon isotopes is a new method which we will also use for determining the age of structurally bound carbon in roots (see project "Age of tree root and understorey rhizome carbon across ecological gradients in boreal forests - radiocarbon isotope approach").
Age of tree root and understorey rhizome carbon across ecological gradients in boreal forests - radiocarbon isotope approach, Academy of Finland 2008-2011.
Long-term effects of soil warming on fine root and mycorrhizal mycelia turnover in boreal forests, Nessling Foundation 2009-2011.
Prof. Dan Berggren Kleja et al., Swedish University of Agricultural Sciences; The effect of long-term soil warming on soil carbon balance in a boreal spruce forest, financed by Formas, 2008-2010
Dr. Ivika Ostonen , and prof. Krista Lõhmus University of Tartu; Fine root adaptation strategies in European coniferous and deciduous forests along a latitudinal gradient, 2008-2011 financed by the National Science Foundation of Estonia, 2008-2011.
Dr. Isabella Børja, Skog og Landskap, Norway, minirhizotrone research.
Cost-network FP 0803 Belowground carbon turnover in European forests, 2009-2013.
Helmisaari, H.-S., Ostonen, I. , Lohmus, K., Derome, J., Lindroos, A.-J., Merilä, P. & Nöjd, P. 2009. Ectomycorrhizal root tips in relation to site and stand characteristics in Norway spruce and Scots pine stands in boreal forests (pdf). Tree Physiology 29(3): 445-456
Helmisaari, H-S. 2009. Roots and carbon allocation - quantity, quality, and controls (pdf). 7th ISRR (International Society of Root Research) Symposium "Root Research and Applications", September 2-4, 2009, Vienna, Austria.
Project leader:
Salemaa, Maija
The Finnish Forest Research Institute,
Vantaa Unit,
PO Box 18 (Jokiniemenkuja 1), FI-01301 VANTAA, FINLAND
Phone: +358 29 532 5479
E-mail: maija.salemaa@metla.fi
Other researchers: Helmisaari, Heljä-Sisko (2009-10)
Updated 02.02.2013
Comments