Roots
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The roots of trees are only sedomly good visible as in this example with an European beech.
Photo: Marco Walser
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Fig. 2: During the strom Lothar in Dezember 1999 many trees were uprooted and their large root systems exposed.
Photo: Marco Walser
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AFig. 3: Living fine roots are elastic and turgescent, and the tips are in general colonized with mycorrhizal fungi.
Photo: Anika Richter
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Fig. 4: Dead fine roots are brittle and hollow, and the branchings and tips are often broken off.
Photo: Anika Richter
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Fig. 5: Living fine root of a Norway spruce with the tip colonized by hyphae of a mycorrhizal fungus (mycorrhiza).
Photo: Ivano Brunner
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Fig. 6: Microscopical longitudinal section of a living fine root of an European chestnut.
Photo: Ivano Brunner
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In that research topic, the roots of trees are investigated in relation to soil properties. Roots take up water and nutrients from the soil, they store carbon compounds, and they provide physical stability. While the fine roots are evident in the uptake of water and nutrients, both fine and coarse roots are relevant in tree stability. Our research delivers an important contribution to the biology and ecology of tree roots, and the results support science as well as extension and teaching. Our aim is the support of the sustainability of forest ecosystems.
Roots - the hidden half
Roots take up water and nutrients from the soil, they store carbon compounds, and they provide physical stabilisation. While the fine roots (roots with a diameter below 2 mm) are evident in the uptake of water and nutrients, both fine and coarse roots (roots with a diameter of 2 mm and above) are relevant in tree stability. Furthermore, fine roots of trees undergo constant replacement in root turnover and provide a large biomass input to the soil containing both carbon and mineral nutrients. Hence fine roots are important in carbon fluxes to soils and in carbon storage in soils, as well as in below-ground recycling of nutrients such as nitrogen, phosphorus, magnesium and calcium. Estimations from temperate forests in Central Europe showed that about 52 t/ha are coarse tree roots and 2.5 t/ha are fine tree roots. Thus, about one third of the forest stands biomass are roots.
Because tree roots are in an intimate contact with their surrounding soil, they somehow reflect the soils chemical and physical properties and conditions. Roots are also able to react to changes in soils with morphological, physiological, and molecular alterations. Therefore, tree roots can be used as indicators.
Research aims
- Development of suitable and reliable methods and tools in order to identify and characterise tree roots.
- Investigation of morphological, physiological, biochemical, and molecular root parameters as reactions to ecological adverse soil conditions such as acidification, eutrophication, high heavy metal contents, drought, elevated temperatures, or compaction.
- Assessment of the contribution of tree roots to the forest soil carbon pools and fluxes, hence to develop and apply methods for improved estimations of root production, mortality, turnover, and decomposition.
- Improvement of physiological, biochemical and molecular methods for the investigation of tree roots of small sample amounts.
- Recording the distribution of tree roots in forest soils, estimation of their impacts on soil functions, e.g. soil stability and soil water properties, and improvement of their services to the sustainability of the forest ecosystems.
Current projects
Soil acidification
Bodenversauerung und Baumwurzelvitalität
Microarray-directed development of biomarkers indicating aluminium stress in trees
Aluminium and heavy metal induced organic acid exudation of forest tree roots
Physiological reactions of chestnut tree roots to acidic soils
Heavy metals
Critical limits and effect based approaches for heavy metals
Root carbon
Fluxes, pools, and turnover of C within the fine root systems of individual trees at a natural forest stand
Influence of above-ground stress on the metabolism of non-structural carbohydrates in poplar roots
Decomposition of litter and fine roots, microbial biomass and activity on LWF-plots
Root distribution
Wurzelverteilung und Wasserhaushaltseigenschaften im Boden
Soil compaction
Soil regeneration after compaction with the help of roots
International cooperations
COST Action FP0803 "Belowground carbon turnover in European forests"
IUFRO Arbeitsgruppe 2.01.13 – Root physiology and symbiosis
Special Issues
Plant Biosystems 141 (3), 390-511 (2007): "Recent Advances in Woody Root Research"
Journal of Forest Research 12 (2), 75-160 (2007): "Development and Function of Roots of Forest Trees in Japan"
Recent publications from our Research Unit
- Brunner I, Godbold DL. 2007. Tree roots in a changing world. Journal of Forest Research 12, 78-82.
- Richter AK, Hajdas I, Frossard E,
Brunner I. 2013. Soil acidity affects fine root turnover of European beech. Plant Biosystems.
DOI:10.1080/11263504.2012.742471.
- Brunner I, Bakker MR, Björk RG, Hirano
Y, Lukac M, Aranda X, Børja I, Eldhuset TD, Helmisaari HS, Jourdan C, Konôpka
B, López BC, Miguel Pérez C, Persson H, Ostonen. I. 2013. Fine-root turnover of
European forest trees revisited: an analysis of data from sequential coring and
ingrowth cores. Plant and Soil. DOI:10.1007/s11104-012-1313-5.
- Endrulat T,
Saurer M, Buchmann N, Brunner I.
2010. Incorporation and remobilization of 13C within the fine-root
systems of individual Abies alba
trees in a temperate coniferous stand. Tree Physiology 30, 1515-1527.
- Hirano Y, Frey B, Brunner I. 2012. Contrasting reactions of roots of
two coniferous tree species to aluminum stress. Environmental and Experimental
Botany 77, 2-18.
- Brunner I, Ruf M, Lüscher P, Sperisen C. 2004. Molecular markers
reveal extensive intraspecific below-ground overlap of silver fir fine
roots. Molecular Ecology 13, 3595-3600.
- Brunner I, Graf Pannatier E, Frey B, Rigling A, Landolt
W, Zimmermann S, Dobbertin M. 2009. Morphological and physiological
responses of Scots pine fine roots to water supply in a climatic dry
region in Switzerland. Tree Physiology 29, 541–550.
- Grisel N, Zoller S, Künzli-Gontarczyk M, Lampart T, Münsterkotter M, Brunner I, Bovet L, Metraux J-P,
Sperisen C. 2010. Transcriptomic
response to aluminum stress in roots of aspen (Populus tremula). BMC Plant Biology 10:185, 1-15.
Involved staff
Ivano Brunner
Beat Frey
Christoph Sperisen
Peter Lüscher
Beat Stierli
Claude Herzog
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