Connecting plant-water interactions across scales and disciplines

The increase in severity, frequency, and global footprint of droughts highlights the urgent need to improve our understanding of plant responses to changes in water availability. This requires better integration and synergy of knowledge from different scientific communities in the field of plant-water interactions, primarily: land-climate modelers, ecophysiologists, and soil hydrologists. Each community describes the soil–plant–atmosphere continuum using different primary variables, focusing on different spatial and temporal scales, invoking different key assumptions, and using different concepts and model structures. A separation between disciplines hinders exchange and thus limits scientific progress. If, on the other hand, dialogue can be established at these interfaces, then this methodological diversity could allow key processes such as stomatal and hydraulic regulation of plants, water storage below the surface and in vegetation, and material flows in the ecosystem to be brought together and deciphered holistically. In this presentation, we synthesize evidence from different angles and scales including leaf water status, soil moisture and ecosystem-scale observations to identify missing links and consistent thresholds that can connect plant-water relations across disciplines.