A framework is presented that is relevant to all terrestrial ecosystems and their modification states. Unpinning the framework is the tool's ability to track change and trends based on assessing effects of land management regimes. Effects of these regimes on criteria & indicators of function, structure and composition are scored using criteria and indicators. Changes in condition, resilience and transformation are assessed relative to fully natural a reference state for each plant community. Assessments are constrained to soil landscape units because this approximates to land manager’s use and management of the landscape. The framework helps decision makers assess and report change at sites and landscapes due to human management and natural drivers.
Spiders by Slidesgo - an introduction to arachnids
Framework for assessing and reporting resilience of native vegetation
1. Framework for assessing and reporting
resilience of native vegetation
Richard Thackway
Lecture presented as part of the Fenner School of Environment and Society,
ANU’s undergraduate course, ENVS3041 Managing Forested Landscapes
8 March 2017
2. Outline
• Concepts and definitions
• Why & how land managers change their landscapes
• A standardised system for assessing and reporting resilience
• The VAST methodology site and landscape
• Case studies - Cumberland State Forest, Sydney
• Lessons
• Conclusions
4. VAST = Vegetation Assets States and Transitions
NVIS = National Vegetation Information System
VIVIVIIIIII0
Native vegetation
cover
Non-native vegetation
cover
Increasing modification caused by use and management
Transitions = trend
Vegetation
thresholds
Reference for
each veg type
(NVIS)
A framework for assessing & reporting
changes in plant communities
Condition states
Residual or
unmodified
Naturally
bare
Modified Transformed Replaced -
Adventive
Replaced -
managed
Replaced -
removed
Thackway & Lesslie (2008) Environmental
Management, 42, 572-90
Diagnostic attributes of VAST states:
• Vegetation structure
• Species composition
• Regenerative capacity
NVIS
5. Change over space
Thackway & Lesslie (2008)
Environmental Management, 42, 572-90
NB: Input dataset biophysical naturalness reclassified using
VAST framework
/ replaced
/ unmodified
VAST 2009
Native
6. How to account for changes in
native veg type, extent and condition?
LMP deliberately &/or unintentionally do this by:
• Modifying
• Removing and replacing
• Enhancing
• Restoring
• Maintaining
• Improving
*
* Natural disturbances
Function
Structure &
Composition
LMP = land management practices
7. Tracking change and trends based assessing
effects of land management regimes
Effects of regimes on criteria
& indicators of function,
structure and composition
Examples
No active interventions Biodiversity protection, minimal use
Harvest products Biomass, fibre, flowers, fruit and nuts
Enhance or improve Rehydrate soils, control invasive
species, reestablish a fire regime, seed
hays
Extirpate or remove Overgrazing, intensive cropping,
pasture improvement, removal of fire
regime, draining wetlands
Reconstruct Revegetate, rehydrate soils, stabilize
soil
Thackway and Freudenberger (2016)
8. A framework that is relevant to all
terrestrial ecosystems and their
modification states
16. A framework for assessing and
reporting vegetation resilience
(space and time)
17. Understanding ecosystem change over time
Indigenous
land
management
First
explorers
Grazing
Degreeof
modification
Logging
Cropping
Site 1
Site 2
Site 3
Time
Reference state
Long
term
rainfall
Long term
disturbance
e.g. wildfire,
cyclones
Revegetation
The same ecosystem e.g. eucalypt open forest with different management histories
t2t1
t3
18. Creating systematic and comprehensive chronology to assess where,
when and how landscapes are transformed relative to a reference
LU = Land Use, LMP = Land Management Practices
VAST Diagnostic attributes
Time
21. Components
(3)
Criteria
(10)
Description of loss or gain relative to pre settlement indicator reference state
(22)
Function
Regenerativecapacity
Fire regime Change in the area /size of fire foot prints
Change in the number of fire starts
Soil hydrology Change in the soil surface water availability
Change in the ground water availability
Soil physical
state
Change in the depth of the A horizon
Change in soil structure.
Soil nutrient
state
Nutrient stress – rundown (deficiency) relative to soil fertility
Nutrient stress – excess (toxicity) relative to soil fertility
Soil biological
state
Change in the recyclers responsible for maintaining soil porosity and nutrient recycling
Change in surface organic matter, soil crusts
Reproductive
potential
Change in the reproductive potential of overstorey structuring species
Change in the reproductive potential of understorey structuring species
Vegetationstructure
Overstorey
structure
Change in the overstorey top height (mean) of the plant community
Change in the overstorey foliage projective cover (mean) of the plant community
Change in the overstorey structural diversity (i.e. a diversity of age classes) of the stand
Understorey
structure
Change in the understorey top height (mean) of the plant community
Change in the understorey ground cover (mean) of the plant community
Change in the understorey structural diversity (i.e. a diversity of age classes) of the plant
Species
Composition
Overstorey
composition
Change in the densities of overstorey species functional groups
Change in no.s of indigenous overstorey species relative to the number of exotic species
Understorey
composition
Change in the densities of understorey species functional groups
Change in no.s of indigenous understorey species relative to the number of exotic species
23. Generate total indices for ‘transformation site’ for each year of the
historical record. Validate using Expert Knowledge
• Compile and collate effects of land
management on criteria (10) and
indicators (22) over time.
• Evaluate impacts on the plant
community over time
Transformation site
• Compile and collate effects of
land management on criteria
(10) and indicators (22)
Reference state/sites
Score all 22 indicators for ‘transformation site’ relative to the
‘reference site’. 0 = major change; 1 = no change
Derive weighted indices for the ‘transformation site’ i.e. regenerative
capacity (55%), vegetation structure (27%) and species composition (18%)
by adding predefined indicators
General process for tracking change over time
using the VAST-2 system
24. Definitions
• Change in a plant community type due to effects of land
management practices:
– Structure
– Composition
– Regenerative capacity
• Resilience = capacity of an plant community to recover toward
a reference state following change/s in land management
• Transformation = changes to vegetation condition over time
• Condition, resilience and transformation are assessed relative
to fully natural a reference state
Vegetation condition
25. Synthesising information using a hierarchy
• Level 1: Scores over time
• Level 2: Components
• Level 3: Criteria
• Level 4: Indicators
• Level 5: Field measures/observations (Direct) and Expert /inference
models (Indirect)
26. Components
(Level 2)
Criteria
(Level 3)
Description of loss or gain relative to pre settlement indicator reference state
(Level 4)Regenerativecapacity
Function
Natural
disturbance
Change in the area /size of events
Change in the number of events
Soil hydrology Change in the soil surface water availability
Change in the ground water availability
Soil physical
state
Change in the depth of the A horizon
Change in soil structure.
Soil nutrient
state
Nutrient stress – rundown (deficiency) relative to soil fertility
Nutrient stress – excess (toxicity) relative to soil fertility
Soil biological
state
Change in the recyclers responsible for maintaining soil porosity and nutrient recycling
Change in surface organic matter, soil crusts
Reproductive
potential
Change in the reproductive potential of overstorey structuring species
Change in the reproductive potential of understorey structuring species
Vegetationstructure
Overstorey
structure
Change in the overstorey top height (mean) of the plant community
Change in the overstorey foliage projective cover (mean) of the plant community
Change in the overstorey structural diversity (i.e. a diversity of age classes) of the stand
Understorey
structure
Change in the understorey top height (mean) of the plant community
Change in the understorey ground cover (mean) of the plant community
Change in the understorey structural diversity (i.e. a diversity of age classes) of the plant
Species
Composition
Overstorey
composition
Change in the densities of overstorey species functional groups
Change in no.s of indigenous overstorey species relative to the number of exotic species
Understorey
composition
Change in the densities of understorey species functional groups
Change in no.s of indigenous understorey species relative to the number of exotic species
29. Photograph: Peter Coyne
1740
1906
Phillip Island, South Pacific
Photograph: State Library NSW: JW Beattie
By 1860 already denuded
(Removed and replaced: VAST VI)
Reference (Unmodified: VAST I)
Pine – Hardwood Subtropical Rainforest
31. year
score%
Pine – Hardwood Subtropical Rainforest, Phillip Island, Sth Pacific
Pigs
released
Uninhabited
island
Pigs died
out
Goats and
rabbits released
Goats died
out
Rabbits
eradicated
Rabbit
control
commenced
Commenced
passive & active
restoration.
Minimal ecological
monitoring
34. Topsoil briefly
stockpiled <10 days
Timber harvested and
remaining trees and
vegetation removed
1974 (0 years old)
Photographs: Barry Fox
(Removed and replaced: VAST VI)
35. Sand sprayed and dried and
re-shaped as a contoured
dune
Sandmining
Dredge
Original
Eucalypt open forest
Dredge
Pond
Smiths Lake
Dredge Pond
1974 (0 years old)
Photographs: Barry Fox
(Removed and replaced: VAST VI)
36. 1974-75 (0-6 months old)
Topsoil
spread
over
reshaped
sand
dune
Sorghum
cover
crop
planted
1974 (One month old) 1975 (< 6 months old)
Photograph: Barry Fox
(Removed and replaced: VAST VI)
(Removed and managed: VAST V)
37. 2014 (39 years later)
Photographs: Richard Thackway(Unmodified: VAST II)
42. • Network of collaborators
• Ecologists, land managers, academics, research scientists,
environmental historians
• Inputs
• Reference state
• Historical record of land use & Land management practices
• Historical record of major natural events e.g. droughts, fires, floods,
cyclones, average rainfall 1900-2012
• Observed interactions e.g. rabbits, sheep and drought
• Observations and quantitative measures of effects
• Include written, oral, artistic, photographic and remote sensing
Lessons: Resources needed at site level
43. Lessons: site vs landscape
1. Constrain assessments to soil landscape units because this
approximates to land manager’s
2. Must account for major natural events e.g. flood, fire, cyclone
3. Remote sensing is only part of the solution –
a) Some measures of remote sensing e.g. greenness of crown health may not be
directly related to vegetation condition
4. Tracking outcomes of management interventions
a) Must collect on-ground data and have a model for linking change to datasets
derived from remote sensing
44. Lessons: Importance of dynamics
Assume rainfall is main driver of natural system dynamics
• Period 1900 - 2013
• Average seasonal rainfall (summer, autumn, …)
• Rainfall anomaly is calculated above and below the mean
• Two year running trend line fitted
46. Transformationscore
Years
1800
2016
Reference
Relevance to developing scenarios for future
landscape transformation
Modified
Transformed
Replaced/
managed
Residual
Replaced/
adventive
VAST Classes
1850 19501900 2000 2050 2100
Replaced/
removed
Baseline
Classes can be modelled as extent and condition
Extentnative
47. Conclusions
• A framework that helps decision makers assess and report change at
sites and landscapes due to human management and natural drivers
• A tool (i.e. VAST) for assisting in reporting on the current status of
Australia’s vegetation types - used in
– National State of the Environment Report (2011)
• An accounting tool (VAST-2) for reporting change and trend in the
transformation of vegetation types at sites - used in
– National State of the Forests Report (2013)
– Regional Environmental Accounts (Wentworth Group of Concerned
Scientists 2015)
48. More info & Acknowledgements
More information
http://www.vasttransformations.com/
http://portal.tern.org.au/search
http://aceas-data.science.uq.edu.au/portal/
Acknowledgements
• Many public and private land managers, land management agencies,
consultants and researchers have assisted in the development of VAST & VAST-2