Foliage projective covers of overstorey and understorey strata of mature vegetation in Australia

Abstract

At maturity, both overstory and understory foliage projective covers (FPC) tend to reach steady-state values which are correlated with the evaporative coefficient (k) in the water balance equation of the soil-plant-atmosphere continuum. Overstory FPC of mature communities increase linearly from 20-85% along the moisture gradient from arid to humid regions. Understory FPC in mature communities are relatively constant along the same moisture gradient, increasing only slightly from 40 to 47%. Plant communities which have overstory FPC different from the normal appear to show a compensatory decrease or increase in understory FPC so that the sum of the FPC of overstory and understory is equal to that predicted for the region.