Growth and vitality of fine roots of Norway spruce as influenced by experimental and natural drought
Final Report Abstract
Norway spruce is one of the economically most important tree species of Central Europe. However, this species is known to be particularly drought-sensitive and, thus, is maybe threatened by a higher frequency of summer droughts under a changing climate. Moreover, stronger soil frost events in winter due to reductions in snow cover may also affect the vitality of this species. Within the framework of the DFG Research Unit 562, this project investigates effects of increasing soil frost and soil drought on the growth, mortality and morphology of spruce fine roots with a multi-scale approach including experimental frost and soil drought application to mature spruce trees, a mesocosm experiment with spruce saplings, and a transect study in 9 mature spruce stands along a natural rainfall gradient. Our results show that both accelerated frost intensity and increased soil drought lead to increased fine root mortality and turnover, thereby stimulating root-derived carbon flux to the soil. While spruce saplings seem to have a rather uniform above- vs. belowground response to increasing levels of soil drought, mature stands of Norway spruce seem to respond with an increase in fine root biomass to decreasing water supply and show a decrease in aboveground productivity. We conclude that a better understanding of the response of the fine root system of Norway spruce to altered soil hydrological and temperature regimes is important for assessing global climate change effects on this tree species.
Publications
- (2008): Effects of experimental drought on the fine root system of mature Norway spruce. Forest Ecology and Management 256: 1151-1159
Gaul, D., Hertel, D., Borken, W., Matzner, E., Leuschner, Ch.
- (2008): Effects of experimental frost on the fine root system of mature Norway spruce. Journal of Plant Nutrition and Soil Science 171: 690-698
Gaul, D., Hertel, D., Leuschner, Ch.
- (2009): Estimating fine root longevity in a temperate Norway spruce forest using three independent methods. Functional Plant Biology 36: 11-19
Gaul, D., Hertel, D., Leuschner, Ch.
- (2010): Investigating flow mechanisms in a forest soil by mixed-effects modelling. European Journal of Soil Science 61, 1079-1090
Bogner, C., Gaul, D., Kolb, A., Schmiedinger, I., Huwe, B.
