Vertical decoupling of soil nutrients and water under climate warming reduces plant cumulative nutrient uptake, water?use efficiency and productivity

Warming-induced desiccation of the fertile topsoil layer could lead to decreased nutrient diffusion, mobility, mineralization and uptake by roots. Increased vertical decoupling between nutrients in water availability subsoil/bedrock layers under warming thereby reduce cumulative over growing season. We used a Mediterranean semiarid shrubland as model system assess impacts warming-induced on plant water- nutrient-use patterns. A 6 yr manipulative field experiment examined effects (2.5°C), rainfall reduction (30%) their combination soil resource utilization Helianthemum squamatum shrubs. drier (‘growth pool’) led greater proportional from deeper, wetter, but less (‘maintenance plants. This was linked uptake, increased nonstomatal (nutritional) limitation photosynthesis reduced water-use efficiency, above-ground biomass growth drought survival. Whereas shift stored deep may buffer negative impact transpiration, this plastic response cannot compensate for associated carbon assimilation, which compromise capacity plants adjust warmer climate.