180 Monitoring Threatened Species and Ecological Communities
Introduction
The Western Australian Department of Biodiversity, Conservation and Attractions
(DBCA) is responsible for conserving native biodiversity in Western Australia
(WA). It manages 26.7 million ha of national parks, state forests and other reserves
(10.5% of the land area of WA) and is responsible for fire preparedness and pest
animal and weed control over 89 million ha of unallocated Crown land and
unmanaged reserves (a total land area greater than New South Wales, Victoria and
Tasmania combined). It also manages 2.5 million ha of marine parks and reserves.
The WA fauna include 245 animal species and 425 f lora species listed as threatened
at the state level.
Monitoring is carried out by DBCA for various reasons including tracking: (1)
population trends; (2) the status of threats; (3) the effectiveness of threat abatement
activities; (4) the effectiveness of other conservation actions; (5) particular areas of
interest; and (6) responses to management activities and disturbance (e.g. timber
harvesting, prescribed burning, wildfire). Long-term monitoring of mammals in
the Upper Warren region (UWR) is used here as a case study to consider the value
of monitoring more generally.
Mammal monitoring in the Upper Warren Region
The UWR is 300 km south of Perth covering over 144 000 ha of nature reserve,
national park and state forest, with forests and woodlands dominated by jarrah
Eucalyptus marginata, marri Corymbia calophylla and wandoo Eucalyptus wandoo
(Department of Environment and Conservation 2012; Fig. 13.1). The region is a
priority fauna conservation area because it supports many threatened and priority
mammal species that have undergone broad-scale and severe declines elsewhere
(e.g. numbat Myrmecobius fasciatus, ngwayir or western ringtail possum
Pseudocheirus occidentalis, woylie or brush-tailed bettong Bettongia penicillata,
tammar wallaby Notamacropus eugenii, chuditch or western quoll Dasyurus
geoffroii, wambenger or brush-tailed phascogale Phascogale tapoatafa, quenda or
southern brown bandicoot Isoodon obesulus and koomal or common brushtail
possum Trichosurus vulpecula).
Fire, timber harvesting, the control of the introduced red fox Vulpes vulpes and
translocations of some native animals have been significant management activities
in the region (Wayne et al. 2006, 2017). Some areas have been infected with the
introduced soil-borne plant pathogen Phytophthora cinnamomi and most of the
public forests are managed to minimise its spread (Department of Environment
and Conservation 2012).
Long-term terrestrial vertebrate monitoring on the public conservation estate
in the UWR has expanded greatly since 1974. Trapping transects of wire cages,
grids of Elliott box traps and pitfall traps, spotlight transects, nest box grids and
transects and arrays of sand plots, have been the principle monitoring methods