You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Influence of Soil Heterogeneity on the Coexistence of Grassland Species
A. H. Fitter
Journal of Ecology
Vol. 70, No. 1 (Mar., 1982), pp. 139-148
Published by: British Ecological Society
Stable URL: http://www.jstor.org/stable/2259869
Page Count: 10
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
(1) In fifteen lowland grasslands, as the quotient of root density in the lower (5-10 cm) layer of soil to that in the upper (0-5 cm) layer increases so there is a decrease in number of species per unit area and in an index of dominance. (2) This quotient, a measure of the heterogeneity of root development, was not related to the difference in pH or concentration of extractable phosphate or potassium in the two soil layers. (3) In a pot experiment an infertile acid sand and a fertile calcareous loam, either mixed or in distinct upper and lower soil layers, were used to grow a standard mixture of five grassland plants. Dominance of one or two species was less marked where there was a distinct lower layer of soil, and this was true irrespective of the total above-ground biomass of all plants. (4) The amount of calcium in the shoots indicates that the species differed in rooting depth, although the spatial distribution of the root system was not analysed. (5) Soil heterogeneity can therefore be shown experimentally to influence the coexistence of species. The distribution of roots in the field may be of great importance in this respect.
Journal of Ecology © 1982 British Ecological Society