Norway Spruce Fine Roots and Fungal Hyphae Grow Deeper in Forest Soils After Extended Drought
Global warming will most likely lead to increased drought stress in forest trees. We wanted to describe the adaptive responses of fine roots and fungal hyphae, at different soil depths, in a Norway spruce stand to long-term drought stress induced by precipitation exclusion over two growing seasons. We used soil cores, minirhizotrons and nylon meshes to estimate growth, biomass and distribution of fine roots and fungal hyphae at different soil depths. In control plots fine roots proliferated in upper soil layers, whereas in drought plots there was no fine root growth in upper soil layers and roots mostly occupied deeper soil layers. Fungal hyphae followed the same pattern as fine roots, with the highest biomass in deeper soil layers in drought plots. We conclude that both fine roots and fungal hyphae respond to long-term drought stress by growing into deeper soil layers.
KeywordsFine root biomass Hyphal biomass Hyphal mesh Minirhizotrons Picea abies
We thank Jaromíra Dreslerová for excellent technical assistance. This work was funded by Iceland, Liechtenstein and Norway through the EEA Financial Mechanism, the Norwegian Financial Mechanism (grant no. A/CZ0046/2/0009), Mendel University in Brno (grant IGA 73/2013), the EEA project FRAMEADAPT EHP-CZ02-OV-1-044-01-2014, and the project “Indicators of Tree Vitality” (Reg. No. CZ.1.07/2.3.00/20.0265), co-financed by the European Social Fund and the Czech Republic. We also acknowledge contribution by COST Actions FP1106 “STReESS” and FP1305 “BioLink”.
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