Sensitivity of simulated productivity to soil characteristics and plant water uptake along drought gradients in the Swiss Alps

•We model soil hydrology in dynamic vegetation models based on observed soil data.•When water is scarce, carbon uptake differs depending on soil assumptions.•Hydrology overrides plant water uptake in DVMs.•Relative vertical root distribution is more important than rooting depth in DVMs. Future climate scenarios indicate a change in precipitation patterns, i.e. in frequency and intensity, and thus a change of water availability for plants. The consequences for ecosystems can be evaluated using dynamic vegetation models (DVMs), but the description of soil properties and assumptions about root distribution and functionality are rather simplistic in many DVMs. We use the LPJ-GUESS model to evaluate (i) the usage of high-quality data sources for describing soil properties and (ii) the assumptions regarding roots. Specifically, we compare simulated carbon uptake when applying the frequently used FAO global soil map vs. soil measurements from 98 sites in the driest regions of Switzerland. The multi-layer soil data were used either as observed (non-aggregated) or aggregated into two layers. At sites with low water holding capacities (whc