1. Risk assessment of Australian ecosystems
David Keith
& IUCN Ecosystem Red
List Working Group

2. Status of Australian ecosystems
- Why we need to know
• International obligations
• Legislative responsibilities
– an informed Australian public
• Evidence-based decision making &
priorities
– env’t investment, trade-offs
• Responses to ecosystem management
• Horizon scanning

3. A framework for synthesis
- risk assessment of ecosystems
• Red List of Species
– International standard for
assessing risks to species
– Generality, data-efficient,
effective communication
• No analogue for assessing
risks to higher levels of
biodiversity

4. Red List criteria for Species
A. Decline in # mature individuals
over 10 yrs / 3 generations
“quantitative” categories
QUANTITATIVE
and / or Vulnerable
THRESHOLDS
B. Small geographic distribution
AND fragmented/decline/fluctuation Endangered
and / or Critically Endangered
C. Small population
AND fragmented/decline/fluctuation
and / or
D. Very small population distribution
“qualitative” categories
AND serious plausible threats
and / or Near Threatened
E. Risk of extinction over Least Concern
next 3 gens/100 yrs Data Deficient
Not Evaluated

5. Assessing risks to ecosystems
Ecosystem concept
(4 defining features, Tansley 1935)
1. Characteristic assemblage of
biota
2. Associated physical
environment
3. Processes & interactions Risks
between components
– among biota
– between biota & environment
4. Spatial extent

6. Towards a Red List of ecosystems
Ecosystem collapse
- transformation, loss of defining features
Risk assessment
- probability of collapse over a given time frame
Semi-arid rangelands (Westoby et al. 1989) – desertification
?
Transient herbivore activity maintains Intense sustained herbivore activity
soil crust & perennial plant cover, destabilises soil surface, degraded soil
limiting soil erosion & degradation inhibits recruitment of perennial plants

7. Threatening processes
Assessing
Ecosystem
distribution
Ecosystem
function
Ecosystem Change
A Declining C Environmt’l Risk model
distribution degradation
for ecosystems
• threats to defining
features (distribution,
Risk of loss
of characteristic
biota & function)
native biota • multiple mechanisms
(causes of threat)
B Small D Altered biotic
processes
• 4 symptoms (of
distribution
decline) = 4 criteria
• plus one overarching
E Quantitative
risk analysis criterion (probability
of collapse)
Threatening processes

8. A. Decline in distribution – criteria & thresholds
A1 A2 A3
Current Future Historic
Status (last 50 yrs) (next 50 yrs) (since c. 1750)
CR ≥80% ≥80% ≥90%
EN ≥50% ≥50% ≥70%
VU ≥30% ≥30% ≥50%
NT almost 30% almost 30% almost 50%
LC <30% <30% <50%
Change in wetland distribution 1960 – 2000
Contraction
1 Expansion
2 4
8
6 7
3 9
10
5
10% net increase in
Remained woodland
Swamp to woodland
distribution (Keith et al. 2010)
Remained swamp
Woodland to swamp
0.5 0 0.5 1 Kilometres
Criterion A = Least Concern

9. C & D: Steps for assessing functional decline
1. Select one/more variables representing
ecosystem function(s)
2. Estimate ‘collapsed state’
– what value of the functional variable indicates
ecosystem collapse?
3. Estimate initial state
– what is the past value of the variable, e.g. 50 yrs ago?
4. Estimate current state
– what is the current value of the variable?
5. Calculate range-standardised decline &
compare with thresholds

10. Selecting variables for assessing
functional declines (C & D)
Must represent key ecosystem driver or
threatening process
• Proximal variables better than indirect ones
• Ecosystem-specific variables better than generic ones
• Sensitive variables better than insensitive ones
• Choice informed by cause/effect process models
(cause-effect diagrammatic summaries of ecosystem dynamics)

11. Selecting functional variables for
ecosystem risk assessment
Mac Nally et al. 2011
S. Cunningham
Salient functional variables
River Red Gum Forests • stream flow (criterion C)
• foliage cover (criterion D)

12. Selecting functional variables for
ecosystem risk assessment
Herbivorous Predatory
fish
Coral reefs Algae
fish
Coral reef
Fishing
Storms
Coral
diseases Water temperature Pollute
& chemistry d runoff
Human population
Climate change
Salient functional variables
• sea surface temperature, ocean acidity
(criterion C)
• coral cover, reef rugosity (criterion D)

13. Estimating relative severity of functional decline
1. Select functional variable (mean ann max river
hgt)
2. Estimate ‘collapse state’ (450-500 cm)
Max River Hgt >700cm
3. Estimate initial state (712 cm)
4. Estimate current state (619 cm)
5. Calculate range-standardised decline
100*(observed)/(collapsed) = VULNERABLE 50 yrs)
Criterion C1 = 35-44% (past
Mean maximum river height (cm)
301000 Average max
10 yr mean average max
Series1
Murray River Inflow (GL/yr)
25 900
Series3
800
20 700
Max river hgt 500 cm 600
15 500
400
10
300
5 200
100
0 0
19601900 1970
1920 1980
1940 1990
1960 2000
1980 2000
2010
Max river hgt <400 cm Year Year

14. Risk assessment outcomes
- level of risk, causes of decline
LC
A
EN-CR contracting future distribution
LC
B EN
EN
LC
LC
C EN-CR declining bioclimatic habitat suitability
DD
DD
D Risk assessment implicates
DD
E
DD climate change as greatest
DD
threat
 adaptation strategies

15. What can risk assessment tell us
about the status of biodiversity?
New Zealand Granite
Gravel Fields: LC
Caribbean Reefs: EN-CR
Murray River Red Gum Murray-Darling Wetlands: EN-CR
Forests: VU
Coolibah-Blackbox WL: EN
Madagascan Tapia Forest: EN
Venezuelan Tepui: LC
Cape Flats Fynbos: CR
Alaskan Kelp Forests: EN-CR
Sth Aust Seagrass
Meadows: EN Coorong Lagoons: CR
European Reedbeds: VU

16. Data requirements
for ecosystem risk assessment
Spatial data
• Ecosystem distribution (derivatives of landcover types, soil
types, terrain)
• Change in distribution & function (time series of landcover,
biomass, hydrology, productivity, disturbance metrics)
Plot/site data
• Species composition (ecosystem description, classification)
• Ecosystem processes (time series of species composition,
abundance, biomass, productivity, hydrology, edaphic, climate)

17. Better environmental reporting
for Australian ecosystems

18. ACEAS working group
- risk assessment of Australian ecosystems
Objectives
• Train Aust & NZ practitioners in Red List
assessment methods
• Review current listing procedures for
ecosystems/communities cf. new international
standard
• Review data requirements for risk assessment and
capacity of TERN to provide (LTERN, AusCover)
• Develop detailed risk assessments for selected Aust
& NZ ecosystems

19. Thank you