Increasing Biodiversity Habitat Using
Urban Green Infrastructure
Dr Caragh Threlfall, Jacinda Murphy & Dr Nick Williams
The University of Melbourne
[email protected]
Biodiverse Cities?
To increase native biodiversity in cities we
can:
1. Stop destroying and degrading remnant habitats
as cities expand
2. Restore and manage remnant habitats
3. Create new habitat in areas not currently
managed for biodiversity
This means integrating habitat into existing
land uses – reconciliation ecology
Urban Green Infrastructure
Green infrastructure is the network of
natural and designed vegetation elements
within our cities and towns, in both public
and private domains
Urban Green Infrastructure
Green walls
Golf courses
Remnant Vegeation
Green roofs
Green infrastructure is
used to improve the
built environment and
provide ecosystem
services
City street trees
WSUD
Vegetated urban design
Parks and gardens
Key Question
Can we use green infrastructure to improve urban
biodiversity outcomes?
1. Large and small green spaces
2. WSUD
3. Green roofs
Ecosystem services from large urban green
spaces: the biodiversity and carbon benefit of
urban golf courses
Dr Nick Williams, Dr Amy Hahs, Dr Steve Livesley, Prof Nigel Stork, Dr Ken Walker
• Melbourne’s golf courses
cover 51km2
• Vegetation management
• Vegetation & soil carbon
• Ground-dwelling & above
ground biodiversity
Measuring green space biodiversity
•Vegetation - biomass,
structure, composition
•Soil & litter properties
•Ground dwelling insects
•Bugs
•Beetles
•Bees
•Insect-eating bats
•Birds
Project design
Comparison of different forms of green space
Australian native bees
• ~2000 species, >150 species in
Melbourne
• No Australian urban bee ecology
studies to date
Pan traps
Sweep Net
Photos: Ken Walker
Homalictus sp.
• 19 species: Colletids,
Halictids, Megachilids and
Apis
Halictid– pointed tip
• Halictidae: most abundant
and widespread
o “Trash” bees – because of
their short, pointed tongue
• Colletidae: Specialised
short, broad tongued bees
were the least widespread
Photos: Ken Walker & WA
Museum
Colletid – broad tip
Structure
Native Plants
Plant Diversity
ANOSIM p<0.01
1.5
Green Space
0.0
-0.5
-1.0
Stress 0.2
-1.5
NMDS2
0.5
1.0
Golf Course
Residential
Urban Parks
-1.5
-1.0
-0.5
0.0
0.5
NMDS1
1.0
1.5
2.0
1.5
Green Space
1.0
0.0
-1.5
-1.0
Halictids
-0.5
NMDS2
0.5
Colletids
Golf Course
Residential
Urban Parks
-1.5
Apis
-1.0
-0.5
0.0
0.5
NMDS1
1.0
1.5
2.0
1.5
Green Space
0.0
-0.5
-1.0
Flower Diversity
Plant Diversity
-1.5
NMDS2
0.5
1.0
Nativeness
Tree Health
Vegetation Structure
Golf Course
Residential
Urban Parks
-1.5
-1.0
-0.5
0.0
0.5
NMDS1
1.0
1.5
2.0
Environmental vectors p<0.01
• Bee community changed
based on:
• Floristics
• Vegetation structure
• The most diverse
communities &
specialised species found
in older, native parks and
golf courses
How can we improve bee
habitat?
• Implement out of play,
unmanaged spaces
• No mow zones
• Prevent human access
• Ensure native flowering
plants are incorporated
in planting designs
• Retain dead trees and
CWD
Summary – Large Green Spaces
Project
• How vegetation is
managed influences what
animals occur
• Large urban green spaces
provide high biodiversity
benefits to many animal
groups
• Restoration can be done
without compromising
recreational values
Street Bioretention Basins
• WSUD elements now
common in cities
• These could be used to
increase urban biodiversity
• Kazemi et al (2009 &
2011) compared insect
diversity of bioretention
basins in Melbourne with
garden beds and lawns on
streets
Street Bioretention Basins
• Biorentention basins had
significantly more insect
diversity
• Most important factors were:
1. Leaf litter depth (ground
dwellers eg. ants)
2. Vegetation structure
3. Number of flowering
plants
4. Size of bioretention basin
Green Roofs
• A roof that uses plants to improve its
performance or appearance
• Can help restore ecosystem function and
biodiversity to high density urban areas
Green roofs as Biodiversity Habitat
• Can be planted with native
species to provide habitat
• In Europe and the US green
roofs have been designed
specifically for local birds,
insects, lizards
Zurich Main Station
Black Redstart Roof
California Academy of Sciences
Black Redstart
Green Roof Research @
The University of Melbourne
Developing green roofs for Australian conditions
• Trialled native plants from granite outcrop and
grassland communities
• Results have led to construction of green roofs
designed support biodiversity
Minifie park Childcare Centre, Balwyn
Pixel Building, Carlton
Insect Diversity on Extensive Green
Roofs in Melbourne
City of Monash succulent Green Roof
• Is there a
difference in the
insect community:
Add another photo of a
sedum roof?
• Succulents vs
Biodiverse roofs
• Comparison to
similar groundlevel vegetation
Minifie Park Biodiverse Green Roof
Insect diversity of green roofs and ground level
sites in Melbourne
14
Ordinal Diversity
12
10
Succulent Roof
8
Biodiverse Roof
6
4
2
0
There are ways of creating new habitat in
cities using GI
www.pineandswallow.com/
We can’t create new remnants, but we
can adapt cities to benefit biodiversity
• But, we need ecological
theory to inform us
• Colonisation distances and
heights
• Structure and composition of
plantings
Raingarden St Kilda
• Minimum area required for
taxa
• Minimum number of habitat
patches required =
metapopulations
Dockside Green, BC
Acknowledgements
• Collaborators: John Rayner, Stefan Arndt, Kath Williams,
Tim Fletcher
• Green Infrastructure Lab
Claire Farrell, Ruth Hughes, Jenny Bear, Jenny McCoy, Kate Lee,
Melanie Deleuze, Xing Ang, Caroline Wilson, Briony Norton, Fran
Alexander, Barbara Gely, Lee Wilson, Jess Mackie, Jarvis Mihsill,
Virginia Harris, Luis Mata
• Funding Agencies
Many thanks
[email protected]