Replication Data for: Root and shoot traits of two common herbs respond differently to drought and fertilization in a multifactorial global change experiment

Background Plants must adapt locally to the recent global change, such as increasing drought exposure or altering nutrient availability. In ecological theory, all functional traits of the plant move towards strategies of stability and resource conservation. In particular fine roots are responsible for water and nutrient uptake and they are highly plastic to stress. In contrast to shoot traits, the dynamics of root growth and the relationship between root and shoot trait responses are still understudied and poorly understood. Methods Therefore, we investigated the shoot and root trait responses of two herbaceous plants, Plantago lanceolata and Rumex acetosa, growing in monoculture or in mixture in a drought x nutrient greenhouse experiment. Results Low-nutrient stress, more than drought stress, led to a strong carbon allocation to the roots, because the root–shoot ratio increased to compensate for stress with improved root development. Roots responded with a more conservative resource use strategy, e.g., an actually decreasing biomass and surface area to drought and, in contrast, unexpectedly with acquisitive strategy by strongly increasing the root–shoot ratio in nutrient-poor conditions. Classical shoot traits such as the decreasing specific leaf area (SLA) indicated a more resource-conservative strategy in response to any stressor. Conclusions Understanding whole-plant responses to global change scenarios urgently requires a much more specific exploration of the adaptation and acclimatisation potential of roots in the application of ecological research. In view of climate-smart land management, the study highlights the importance of maintaining species-rich ecosystems in face of increasing likelihood of global change-type droughts.