Relationship between wind speed and plant hydraulics at the global scale

Abstract

Wind is an important ecological factor for plants as it can increase evapotranspiration and cause dehydration. However, the impact of wind on plant hydraulics at a global scale remains unclear. Here we compiled plant key hydraulic traits, including water potential at 50% loss of hydraulic conductivity (P₅₀), xylem-specific hydraulic conductivity (K_S), leaf area to sapwood area ratio (A_L/A_S) and conduit diameter (D) with 2,786 species-at-site combinations across 1,922 woody species at 469 sites worldwide and analysed their correlations with wind speed. Even with other climatic factors controlled (for example, moisture index, temperature and vapour pressure deficit), wind speed clearly affected plant hydraulics; for example, on average, species from windier sites constructed sapwood with smaller D and lower K_S that was more resilient to drought (more negative P₅₀), deploying less leaf total area for a given sapwood cross-section. Species with these traits may be at an advantage under future climates with higher wind speeds.