Species responses to grazing and environmental factors were studied in an arid halophytic shrubland
community in Western Australia. The grazing responses of major shrub species were defined by using
reciprocal averaging ordination of botanical data, interpreted in conjunction with a similar ordination
of soil chemical properties and measures of soil erosion derived from large-scale aerial photographs. An
apparent small-scale interaction between grazing and soil salinity was also defined. Long-term grazing
pressure is apparently reduced on localised areas of high salinity. Environmental factors affecting species
distribution are complex and appear to include soil salinity, soil cationic balance, geomorphological
variation and the influence of cryptogamic crusts on seedling establishment.
Determining Environmental Factors Affecting Bird Diversity
