WILDLIFE OF LANCEWOOD (ACACIA-SHIRLEYI) THICKETS AND WOODLANDS IN NORTHERN AUSTRALIA .1. VARIATION IN VERTEBRATE SPECIES COMPOSITION ACROSSTHE ENVIRONMENTAL RANGE OCCUPIED BY LANCEWOOD VEGETATION IN THE NORTHERN-TERRITORY
Jcz. Woinarski et A. Fisher, WILDLIFE OF LANCEWOOD (ACACIA-SHIRLEYI) THICKETS AND WOODLANDS IN NORTHERN AUSTRALIA .1. VARIATION IN VERTEBRATE SPECIES COMPOSITION ACROSSTHE ENVIRONMENTAL RANGE OCCUPIED BY LANCEWOOD VEGETATION IN THE NORTHERN-TERRITORY, Wildlife research, 22(4), 1995, pp. 379-411
Vegetation dominated by lancewood (Acacia shirleyi) occurs extensively
across me Northern Territory and Queensland. We sampled the vertebrat
e species composition at 61 patches of lancewood in the Northern Terri
tory (including 22 patches where quadrats were intensively sampled), a
nd relate the distribution of species to a wide range of environmental
characteristics, spatial variables, disturbance and season. Of 165 sp
ecies recorded from lancewood patches, eight species were recorded fro
m more than half of the sampled patches: Pachycephala rufiventris, Pom
atostomus temporalis, Rhipidura leucophrys, Cracticus nigrogularis, Me
lanodryas cucullata, Geopelia cuneata, G. placida and Macropus robustu
s. Environmental variation within sampled lancewood sites was describe
d by classification of 51 quadrats into 7 classes, and the 61 patches
into 5 classes. Vertebrate species showed limited association with thi
s classification, with a few species associated with the occasional co
-dominant tall shrub Macropteranthes kekwickii, other species associat
ed with variation in rockiness or soil texture, and other species asso
ciated with variation in the occurrence of Eucalyptus species within l
ancewood vegetation. An ordination of all quadrats by their vertebrate
species composition suggested a loose patterning associated mainly wi
th latitude and, less strongly, soil texture and co-occurring tree/shr
ub species (notably Eucalyptus and Macropteranthes). Suggesting a depa
uperate and poorly defined vertebrate community in lancewood, quadrats
in small isolated lancewood patches had more species than those in la
rge patches, and this pattern was shown for many individual species. L
ancewood patches showed some impact of grazing and logging, but this w
as generally minor and could not be demonstrated to have any consisten
t relationship with the abundance of individual species. In contrast,
impacts of fire were generally more severe, and were negatively associ
ated with the abundance of relatively many species. Lancewood vegetati
on is not represented in any conservation reserve in the Northern Terr
itory.