Genotypes exhibit no variation in precision foraging in mycorrhizal Norway spruce seedlings

Abstract Aims Fine roots, that comprise the adjustable part of root system, are important in spatially heterogeneous boreal forest soils. We investigated soil exploring patterns Norway spruce ( Picea abies ) seedlings equal height belonging to families representing two contrasting growth phenotypes have shown fast and slow rates long-term experiments. hypothesised fast-growing phenotype would show a more explorative strategy, intense branching, proliferation response nutrient patch, slow-growing be tolerant drought stress. Methods Seedlings were grown flat Perspex microcosms with clod humus placed mid-bottom each microcosm for eight months. The order-based functional classification, branching topology, size seedling systems studied WinRHIZO™ image-analysis software exploration LIGNUM-model simulations. In addition, transpiration, stomatal conductance, net assimilation rate responses measured. Results No differences found early foraging roots nor transpiration between groups. favouring exploitation over phases development regardless group. However, phenotypes, main longer, lateral pool favoured long bifurcated laterals formed larger absorptive area. Conclusions Our results indicate nutrient-poor conditions, better precedes future aboveground spruce.