The Ecophysiology of Veronica Chamaedrys, V. Montana and V. Officinalis. II. The Interaction of Irradiance and Water Regime

The growth responses of Veronica chamaedrys, V. montana and V. officinalis to five levels of irradiance in conjunction with dry, normal and waterlogged soil were investigated using growth analysis. There were no significant differences between species in either relative growth rate (RGR) or unit leaf rate (ULR) and both rates fell with lowered irradiance. Reductions caused by waterlogging were greater than those caused by drought. Water regime had more influence on RGR than did irradiance. Low irradiance caused increases in leaf area ratio (LAR), specific leaf area (SLA) and leaf weight ratio (LWR), although increases in LAR and SLA were suppressed by either soil water deficit or saturation (...)