IALE-OZ
NEWSLETTER
ISSUE
1.3 December
2000
EDITORIAL
Once again,
thankyou to everyone that contributed to this issue. The diverse
range of responses indicates that there is a lot of interesting
landscape ecology work happening in the Australasian region. We
encourage those members who haven’t contributed to think about
doing so in upcoming issues. We would also like to thank
Gary Luck for his mighty efforts in editing the previous issues
of the IALE-OZ Bulletin, and on behalf of the members wish him
well in his new position.
This issue
contains information about upcoming events for the New Year, details
of a new Ecology Centre for the University of Queensland, a response
to Colin Freeman’s article in the June bulletin, and other exciting
contributions. The next issue will be published in March, so start
thinking about any contributions you can make.
Send
all contributions to:
Diane
Pearson dpearson@gis.ntu.edu.au
Amy Hahs a.has@pgrad.unimelb.edu.au
TOP
FROM
THE PRESIDENT
Greetings
and compliments of the season to all IALE-Oz members. We’ve now
been on the go for over a year, and it’s been encouraging to see
the interest and enthusiasm evident in activities and reports
in the Bulletin. This year we say farewell to Gary Luck, who has
been very active as Treasurer and in getting the Bulletin kicked
off. Gary is off to Stanford to take up a post-doc with Paul Ehrlich
and Gretchen Daily. I’d like to thank Gary for his part in getting
IALE-Oz off the ground, and hope that he has a great time in the
States and will return to join us again in a couple of years.
Thanks also to Amy Hahs who has taken over the Bulletin, and Colin
Freeman who takes over as treasurer.
Internationally,
this year has seen a couple of conferences in Europe – one in
Roskilde in Denmark, and the UK-IALE meeting in Bangor – and the
regular US-IALE conference. The NZES meeting in Hamilton in November
also had a very interesting landscape ecology session. We had
an IALE Executive meeting in Bangor, at which we set in train
a number of initiatives which we hope will provide a better deal
for members and facilitate communication across the large and
somewhat diffuse association. We also discussed the problems experienced
by members in relation to the journal Landscape Ecology – I hope
these have now been fixed, but if members continue to have problems
with receipt of the journal, keep letting us know.
Next year
there are a number of activities in the region and elsewhere.
Taiwan is planning a local IALE meeting in February, and there
is an Asian regional meeting scheduled in China in September (details
later). In addition, there is a European Congress scheduled
for July which runs in Stockholm and Tartu (Estonia), with a ferry
ride between the two locations.
Details of this meeting can be found at: http://www.geo.ut.ee/IALE2001/
Here in
Australia, we will begin gearing up for preparations for the 2003
Congress. I will shortly be calling for people willing to take
part in the organizing committee, and we can start considering
potential sponsors, program outlines and so on.
I’ll look
forward to your continued participation in 2001 and hope that
we can continue to expand both in numbers and in levels of activity.
Richard
Hobbs
TOP
LANDSCAPE
ECOLOGY AT THE UNIVERSITY OF QUEENSLAND
A new
faculty-level centre, The Ecology Centre headed by Professor Hugh
Possingham, has been established at the University of Queensland.
The Ecology Centre incorporates the previous Centre for Conservation
Biology, and aims to promote excellence in research in pure and
applied ecology with a particular emphasis on spatial and quantitative
ecology. The Centre is comprised of three research groups: Mathematical
Ecology, Conservation Biology and Landscape Ecology.
Current
and recently completed research activities within the LE group
include:
·
The Development and Implementation of Landscape Metrics for Reporting
Forest Fragmentation at Field and Landscape Levels (project funded
by FWPRDC and conducted jointly with ANU and Queensland Department
of Natural Resources);
· Climate impacts of land cover change in Australia.
ARC SPIRT APAI collaborative grant with Queensland Centre for
Climate Applications. Research is been conducted under supervision
by Peter Lawrence, recipient of the PHD scholarship.
· Conservation and restoration of koala populations in
fragmented landscapes. ARC SPIRT collaborative grant with the
Australian Koala Foundation (John Callaghan) and New South Wales
National Parks and Wildlife Service (Dan Lunney).
The Koala
project will employ a landscape approach, coupled with spatially
explicit population viability models, to the conservation and
restoration of koala populations in fragmented landscapes of eastern
Australia. It differs from previous scientific studies of
the ecology of koalas in that it explicitly considers koala conservation
and restoration needs in the larger landscape, and at a spatial
and temporal scale relevant koala populations. It will quantify
and evaluate the consequences of different management actions
on koala populations living in fragmented landscapes with intensive
land use pressures, and where habitat reservation is not economically
viable. It specifically aims to provide specific information on:
(1) minimum proportion of the landscape conserved or restored,
(2) minimum habitat patch sizes and distributions, (3) associated
carrying capacities, and (4) what constitutes an impenetrable
barrier to population connectivity.
Clive
McAlpine
Email: c.mcalpine@mailbox.uq.edu.au
TOP
PHD
THESIS ABSTRACT
LANDSCAPE DIFFERENCES
IN THE ECOLOGY OF THE RUFOUS TREECREEPER Climacteris rufa
Anthropogenic
habitat modification is a significant threat to the conservation
of global biodiversity. The fragmentation and alteration of woodland
habitat has resulted in the substantial decline of many woodland
bird species in the agricultural regions of southern Australia.
The Rufous Treecreeper Climacteris rufa, a once common woodland
resident, has declined in abundance in the wheatbelt of Western
Australia and appears to be sensitive to habitat fragmentation.
The reasons for this are unclear because our knowledge of the
species and the threats posed by fragmentation are limited.
In
this study, I compared the social organisation, habitat selection,
reproductive success, dispersal and population dynamics of two
Rufous Treecreeper populations living in the Western Australian
wheatbelt. The first population occupied a large (8,500 ha), relatively
undisturbed and unfragmented landscape. The second occurred in
an equivalent sized area that had been substantially modified
by agriculture (Figure 1). I hypothesised that habitat fragmentation
and alteration would adversely affect the viability of the population
living in the agricultural landscape.
In
the unfragmented landscape, treecreepers lived in cooperatively
breeding, territorial groups. A group usually comprised a primary
(assumed to be breeding) male and female, and philopatric offspring
(helpers) from previous breeding seasons. Helpers assisted in
the feeding and caring of nestlings and there was a positive relationship
between group size and reproductive output. Breeding groups often
formed interactive neighbourhoods whereby resident individuals
from one territory would feed nestlings in adjacent territories.
A total of 77.7% of 148 nesting attempts produced at least one
fledgling. Mean annual productivity per breeding group (n = 90
group years) was 2.1 ± 0.18 fledglings. Fledgling and juvenile
survival rates (0.76 ± 0.04 and 0.46 ± 0.03 respectively)
were comparatively high, as was the survival rate of primary males
(0.77 ± 0.06) and females (0.75 ± 0.05).
A
multi-scaled analysis of habitat use in the unfragmented landscape
identified preferential habitat selection by the species at three
spatial scales. At the landscape scale, treecreepers used Wandoo
Eucalyptus wandoo woodland at a significantly higher rate than
predicted by the availability of this woodland type. Territory
selection was positively correlated with the density of hollow
bearing logs and nest sites, and tree age. These structural characteristics
were also positively correlated with reproductive success and
survival in treecreepers, indicating that habitat structure may
be a useful measure of territory quality. Nest sites (hollows)
were preferentially used if they had a spout angle of ³ 50°
and an entrance size of 5 – 10 cm, but nest-site selection was
not related to nest success.
The
ecological traits of the treecreeper population living in the
agricultural landscape differed from the population in the unfragmented
area in a number of ways. Habitat fragmentation in the agricultural
landscape disrupted territory contiguity with adverse consequences
for social interaction. Nest success and annual productivity were
significantly lower in the agricultural landscape, although they
varied between different categories of habitat remnants. Reproductive
success was lowest in grazed remnants supporting comparatively
high population densities. Landscape differences in success did
not appear to be a result of a disparity in nest predation levels,
but may be related to variation in food availability and habitat
quality.
The
spatial structure and dynamics of the subdivided population in
the agricultural landscape were consistent with certain aspects
of metapopulation theory. Treecreepers lived in spatially discrete
local populations that were unlikely to persist without immigration
owing to low reproductive and survival rates. However, movement
between habitat remnants appeared to be sufficient to rescue these
local populations from extinction. Although declining in numbers
during the study, the subdivided population in the agricultural
landscape appeared to be fluctuating around equilibrium owing
to immigration from outside the study area.
The
consequences of habitat fragmentation for the Rufous Treecreeper
are complex and interactive. A reduction in habitat area and an
increase in remnant isolation disrupts the social organisation
of the species and results in small, localised populations that
are susceptible to extinction. Modification of the remaining vegetation
may reduce habitat quality leading to poor reproductive success.
In addition to increasing habitat area and maintaining landscape
connectivity, future management of fragmented landscapes must
focus on improving the quality of remnant vegetation by removing
degrading process and ensuring the recruitment of endemic plant
species.
Figure
1. A) The location of the two study areas in the wheatbelt of
Western Australia. The unfragmented landscape of 8,500 ha was
located in a continuously vegetated area of 12,283 ha in Dryandra
Woodland. The fragmented landscape was a 10,000 ha area located
in the Yilliminning agricultural district. B) The location of
the three study sites in the unfragmented landscape. Each site
contained 10 treecreeper territories. C) The location of the 10
remnants (numbered) containing treecreepers in the fragmented
landscape. The remnant category, approximate size, and the number
of territories in each remnant were: 1 – large ungrazed, 250 ha,
two territories; 2 – large ungrazed, 70 ha, seven territories;
3 – large grazed, 60 ha, eight territories; 4 to 7 – small ungrazed,
10 to 30 ha, six territories; 8 to 10 – small grazed, 10 to 30
ha, seven territories.
Gary
Luck – PhD thesis abstract
TOP
EXCITING
CHALLENGES
In the
June issue of our Newsletter (No. 1.2) Col Freeman challenged
us to be precise and clear in how we use the term “Landscape”,
because ‘size does matter’. Col noted that how an animal species
responds to habitat fragmentation is very scale dependent, and
he refers us to the writings of Kimberley With on this theme.
The
national importance of species responses and landscape scale-dependencies,
and how this is a huge, but exciting, challenge for us landscape
ecologists, was made clear to me at a recent workshop held by
the Rangeland Monitoring Theme of the National Land and Water
Resources Audit http://www.nlwra.gov.au/full/index.html.
This workshop, with rangelands monitoring people from all States
and Territories, was charged with putting together a system for
‘tracking changes’ in Australia’s vast arid and semiarid landscapes
that are grazed by feral and domestic animals. A key point made
repeatedly in discussions (a point I highlighted in colour, bold
type and underlined in red) was the need and desire for rangeland
monitoring to move beyond measuring indicators of vegetation change,
such as the cover of forage grasses. It is now recognised and
accepted that rangeland monitoring must measure indicators of
landscape function, defined as the capacity of a landscape to
not only retain vital resources such as water and nutrients, but
to provide the habitats essential for fauna of all kinds.
An
exciting challenge for us landscape ecologists will be identifying
and validating landscape function indicators that apply across
scales from local hillslopes to catchments. Can we find indicators
of landscape attributes that are meaningful to species of concern,
both animals and plants, and that can be measured through time
with practical tools? For example, can we identify and demonstrate
that a given index of habitat fragmentation, say one obtained
by using new hyper-spectral, high-resolution satellite images,
really relates to how a species, such as the Gouldian Finch, is
changing its distribution across savannas and woodlands as these
landscapes become fragmented?
John
Ludwig
TOP
POSTGRADUATE
RESEARCH OPPORTUNITY AT NTU
Project
Title
Linking patterns to process: Using airborne multi-spectral digital
photography to detect patterns of vegetation and urban infrastructure
in the Darwin area.
Background
The study is located in the Darwin metropolitan area within the
Darwin Harbour catchment in the Top End of the Northern Territory.
This urban area has expanded rapidly since cyclone Tracy, some
25 years ago.
This project is part of a socio-ecological study to establish
principles governing the sustainability of developing anthropogeneric
ecosystems. It is intended that this will contribute to a planning,
design and management support system for facilitating community
involvement in the ESD process
The emerging urban vegetation cover, together with the associated
infrastructure is influencing the flow of energy and materials
in complex ways, impacting on the urban environment. Surface
run-off in catchments and heat balances in the atmosphere are
influenced by changes to land cover which may have adverse consequences
for the quality of life particularly if anticipated increases
in precipitation and atmospheric heating are realised.
These processes and their effects need to be better understood,
if criteria for managing urban vegetation to enhance sustainable
outcomes, particularly in the light of impending greenhouse scenarios,
are to be developed
The
Project
This project will involve an assessment of vegetation cover
as well as other surface cover types in the Darwin urban area.
The aim of this project is to try to establish relationships with
various landscape processes and associated natural and human causal
agents by linking patterns detectable from remotely sensed data
to processes.
The
major aim of this project is to establish a methodology for integrating
GIS data layers of property / zone boundaries with remotely sensed
data for the extraction of ground cover types, vegetation density,
and vegetation patterns. Airborne, high-resolution multi-spectral
digital photography is available for this purpose. The pattern
of vegetation and urban infrastructure (housing and paved area)
is expected to show strong correlation with both social, and environmental
statistics and their bearing to sustainability should be assessed.
This
project would make an excellent honours project and there is the
possibility of a good student obtaining a top-up scholarship sponsored
by the North Australian Remote Sensing and GIS conference (NARGIS)
to the order of $4000.
For
further information please contact:
Diane Pearson
Ph: 08 8946 6046
Email: diane.pearson@ntu.edu.au
Carl
Menges
Ph: 08 8946 6739
Email: carl.menges@ntu.edu.au
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