LEAF-CANOPY-INDUCED SEED DORMANCY IN A GRASSLAND FLORA

Authors


  • *

    Present address: Department of Biology, Open University, Walton Hall, Milton Keynes, Buckinghamshire, U.K.

SUMMARY

The germination of 27 species from calcareous grassland was tested in three light treatments in the laboratory: in darkness, under tungsten lamps and under a leaf-canopy. Germination was significantly lower under a leaf-canopy than in the dark in 17 species. The phenomena of leaf-canopy induced dormancy was not associated with the life-span of species, though there was a weak, negative relationship with seed weight amongst 20 perennials in the sample. It is suggested that the co-existence of species at high density in calcareous grasslands may, in part, be explained by differences in germination response to fine-grained variations in the light environment at the soil surface.

Ancillary