Comparative post-fire water relations of selected reseeding and resprouting fynbos plants in the Jonkershoek Valley, Cape Province, South Africa

Abstract

Leaf area development has been proposed as a simple predictor of post-fire streamflow response in the mountain catchments of the south-western Cape, South Africa. Implicit in this proposal is the assumption that transpiration rates per unit leaf area of reseeders and resprouters are similar. This assumption was tested by studying the water relations of selected fynbos plants after a fire in a mountain catchment in the Jonkershoek Valley near Stellenbosch for nearly two years. Stomatal conductances and xylem pressure potentials were measured and transpiration rates were estimated for three reseeding species and four resprouting species. There was no clear difference between the daily transpiration rates of reseeding and resprouting plants. The shallow-rooted resprouters responded similarly to the reseeders; moderate water stress (− 3 to − 4 MPa) and reduced transpiration (