DARLING RIVERINE PLAINS BIOREGION Background Report

16/08/02 Darling Riverine Plains Bioregion Background Report
2 ABIOTIC FEATURES
2.1 INTRODUCTION
In this section the climate, geology, topography, soils and hydrology of the DRP are
described to provide a basis for mapping and predicting the distribution and stability of plant
communities, habitats and species distributions. Predictive distributions are essential as
survey cannot cover the entire land surface. This bioregion is strongly influenced by water
systems and the hydrological parameters are crucial in the biological assessment of the
region.
The effect of human activities, particularly clearing and agricultural activities also need to be
understood in order to assess the changes to plant and animal distribution patterns, population
viability and provenance, water quality and the conservation protocols required. Activities
within the DRP can have an impact on flora and fauna outside the bioregion, for example, the
disruption of migration routes for migratory vertebrate species or the loss of migratory
invertebrate species through control of larval stages in agricultural areas. Activities within
the DRP can also impact on downstream riverine health, water supply and water quality.
Consideration of abiotic factors is important in the development of a meaningful subdivision
of the Bioregion into smaller, manageable units. Boundaries previously defined within the
DRP are outlined in this section.
2.2 CLIMATE
Almost all of the DRP lies within the semi-arid zone of New South Wales, except for a small
portion of the eastern edge that extends into the temperate zone. The semi-arid zone covers an
extensive area and in order to evaluate the climatic influence on the ecological processes of
that area the climatic data for six meteorological stations across the bioregion are used in the
following analysis (Table 2.1, Australian Meteorological Bureau).
Table 2.1 DRP meteorological stations used in this analysis
Town Location within DRP Latitude Longitude Elevation Years of
(m)
records
Moree north-east 29.50 S 149.90 E 207 86
Mungindi northern NSW border 28.98 S 148.99 E 160 113
Walgett central 30.04 S 148.12 E 133 121
Trangie south-east boundary 32.03 S 147.98 E 219 102
Bourke north-west at the beginning of the 30.09 S 145.94 E 106 129
Darling corridor
Menindee south-western on the Darling River
corridor
32.40 S 142.42 E 61 124
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