transformations
Tracking the
Transformation
of Vegetated Landscapes
using the VAST-2 system
Version 1.1
5 AUGUST 2015
RICHARD THACKWAY
The VAST-2 system
VA S T
VAST-2 addresses several key questions:
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V E G E TAT I O N A S S E T S , S TAT E S & T R A N S I T I O N S
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The VAST-2 system integrates three types of information: citizen science
reporting; targeted representative scientific sampling by acknowledged
ecological experts; and broader scale monitoring using multi-temporal
and multi-spatial remotely sensed imagery.
What is the condition of the native vegetation on my
site relative to an accepted national standard?
What role has historic land use and land management
practices had in transforming or modifying the
condition of the native vegetation on my site?
How can I assess and report the condition of my native vegetation resulting from my management interventions?
As a land manager what can I do to change the
condition of the native vegetation of my site?
VAST-2 is designed to assist researchers and land
managers record site-based land use and land management
practices and their effects on the condition of native plant
communities.
Documenting the historic record of land use and
management at a site and assessing the effects on vegetation
condition need not be a complex task.
VAST-2 offers certainty for land managers and planners
through providing a nationally consistent approach for
assessing and reporting vegetation condition at sites over
time. Quantitative and qualitative data and information
as well as personal communications can be compiled and
evaluated to determine changes in the condition of a plant
community over time.
Tracking the
Transformation of
Vegetated Landscapes
using the VAST-2
system
Almost all of Australia’s vegetated landscapes have
been affected by changes in land-use and landmanagement practices. The continent is now a
diverse mosaic of fragmented and modified native
vegetation, and converted and replaced vegetation
cover types. Compiling a record of the responses of
plant communities to land-use changes would assist
land managers make improvements in their practices
to meet wider social, economic and environmental
goals. However, documenting the historical and
contemporary use and management of a site and
assessing the effects on vegetation condition can
be a complex task. Debate of what is a consistent
approach to reporting changes in the condition of plant
communities over space and time continues between
those involved in conservation and protection,
and those responsible for sustainable land use and
management. This particularly the case with
native vegetation.
VAST-2 delivers ecologically meaningful information to
assist decision makers to track and understand complex
ecological processes including degradation, restoration and
regeneration. As a tool, the system provides a framework for
identifying potential risks and barriers to achieving success,
demonstrating progress toward vegetation condition targets,
and selecting sites which represent least-cost options for
future land use changes. It also highlights the importance
of an accounting system that can be used to track the
sustainable use and management of native vegetation across
all land use types and has relevance for managing biodiversity.
The easy to understand graphs enable ecologists and land
managers to explore options for future improvements
through adaptive management of the site. As a historical
record this information is also useful for environmental
planners, educators, historians, industry groups and the
wider public.
The VAST-2 system combines a structured spatiotemporal
literature review and stakeholder interviews with 22
vegetation transformation indicators (Table 1) to assess
and report the outcomes/effects of land management
interventions on native plant communities. Change is
assessed relative to an unmodified reference state.
What are the benefits of the VAST-2 system for
decision makers?
VAST-2:
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VAST-2 describes transformation pathways of native
vegetation, including positive and negative feedbacks and
transitions from one condition state to another, including
the replacement, removal or recovery of native vegetation.
It offers a robust and flexible system that has been tested
in Australia’s tropical, sub-tropical, arid, semi-arid, and
temperate bioregions.
empowers land managers to engage equally with ecologists and researchers at the point of land management decisions;
establishes a logical link between land management practice change and their effects on plant communities over time using a checklist of
22 indicators of vegetation structure, species composition and regenerative capacity or function;
enables observational, qualitative and quantitative data/information to be used to populate the 22 indicators, which are analysed relative
to impacts of land use and management;
illustrates complex ecological patterns and processes using simple to understand graphical tools;
highlights options and future trade-offs for decision-makers.
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FAQ
What is vegetation condition?
The VAST-2 system defines the condition of native plant
community types relative to a fully natural reference state
using indicators/attributes of regenerative capacity (function),
vegetation structure and species composition. The purpose
for this definition is to enable decision makers to track the
condition of plant community types over time due to changes
in land management practices and the effects these practices
have on changing indicators/attributes of regenerative capacity
(function), vegetation structure and species composition.
This definition assists decision makers to understand how
land management practices are used to transform vegetated
landscapes to produce multiple benefits i.e. ecosystem
services. The definition and the VAST-2 system have relevance
to the management of biodiversity.
Consistent with this definition vegetation condition is a
weighted transformation index comprised of 22 indicators
and three components i.e. vegetation structure, species
composition and regenerative capacity or function (Table 1).
Indicators are aggregated using an additive hierarchical system
relative to the plant community’s reference state (Figure 1).
What is the difference between VAST and VAST-2?
Initially the VAST (Vegetation Assets, States and Transitions)
system was developed to describe and map changes in
vegetation over time through a series of condition classes
or states (Thackway and Lesslie 2006, 2008).VAST-2 was
developed out of a need to implement a system to routinely
report changes in condition states over time.VAST-2 is
an enhancement to the VAST method which will enable
identification of the factors contributing to those changes in
state as a result of changes in management practice.
What is a VAST-2 site?
A uniform area defined using topographic position e.g.
depression, flats and lower slopes, mid slopes, upper and
ridge lines; geology and soil type. The native vegetation of the
site is relatively uniform throughout an area. The dimensions
of the site remain constant back in time, now and into the
future. A site is a representative soil-landscape association
and associated plant community. The land use and land
management of the site may change over time.VAST-2 records
these practices and their effects at the site (i.e. soil-landscape
association) over time.
What is a historical record?
A historical record starts at the point of first contact by
European settlers and includes a comprehensive list of
historic and contemporary measurements and observations
where these are available. This record also includes an
acknowledgement of the indigenous people who managed the
site at the time of European settlement.
How is change and trend assessed?
Site-based effects of land management practices are scored
using 22 indicators. Each indicator is benchmarked relative
to its reference state for that indicator. A transformation
index is calculated by aggregating the 22 indicators and three
components for each year of the historical record.
For each time period at a Transformation site, each indicator
(Table 1) is given a score relative to the reference state.
Observed and/or measured changes in indicators range
from 0 to 1, where 1 represents a natural unmodified plant
community (as it would have been without post settlement
human intervention) and 0 is where that ecological function is
absent.
Why does VAST-2 use criteria and indicators?
Vegetation condition is defined using components of
structure, composition and function or regenerative capacity.
Each of these is further delimited using a hierarchy of criteria
and indicators (Figure 1).
VAST-2 uses this framework in combination with systematic
and repeated observations of land management practices
over time to assess the effects of these practices on the
22 indicators and 10 criteria. Figure 2 is an evidence-based
account of the effects that land use and land management have
had in a selected soil-landscape association of the indicators,
criteria and components of vegetation condition.
For decision makers, Figure 2 represents a baseline
assessment for planning future change at the site. As a
diagnostic tool, the land manager/s can utilize this account to
discuss and plan adaptive management strategies within a soillandscape association by modifying, removing and replacing,
enhancing, restoring, maintaining and/or improving the
10 criteria:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Soil hydrological status
Soil physical status
Soil chemical status
Soil biological status
Fire regime
Reproductive potential
Overstorey structure
Understorey structure
Overstorey composition
Understorey composition
The land manager is encouraged to establish fixed monitoring
points or transects within the key soil-landscape associations
and to measure, observe and document through time
attributes changes in land management interventions and the
22 indicators. The role of specialists should be considered in
stratifying sites, using standardized field and database methods
to collect and analyze the attribute data and populate the
VAST-2 indicators in Table 1.
Why use indicators describe to describe response
and change?
The 22 indicators describe the response variables or core
attributes of a plant community and its environment that are
changed by land management practices. Species composition
indicators include richness and functional groups; vegetation
structure indicators include height, cover and age structure.
Regenerative capacity indicators include fire, soil nutrients, soil
structure, soil hydrology and reproductive potential (Table 1).
Why does VAST-2 use a bioregional approach?
Establishing a stratified national system of monitoring sites
to track the response of large numbers of similar land
management interventions is unworkable. Arguably efficiencies
can be achieved by selecting a few representative VAST-2
sites which are linked to on­going and high quality ecological
sites located in the same bioregional context e.g. site data
collected at long term monitoring sites within the same land
unit, land system, sub-IBRA2 or bioregion. These bioregional
level measurements and observations of vegetation and
environmental responses can also be linked to vegetation
and environmental indicators. For these reasons it is not
critical to establish a dense network of comprehensive and
representative VAST-2 long term monitoring sites.
Why does VAST-2 establish a partnership between
land managers and ecologists?
Land manager initiated records and collections of information
(formal and informal) about the management of native
vegetation represent an as yet largely untapped source of
information about the transformation of Australia’s vegetated
landscapes. Land manager information represents valid and
useful information which can be compiled and evaluated
using a systematic framework. Using the VAST-2 system
locally acknowledged ecologists are engaged to evaluate the
historical record of land managers and the reported effects
of land management practices on the 22 indicators at a site.
Ecologists and land managers working together contribute
valuable ecological insights; and together they validate the final
indicator scores and transformation indices.
Land managers invest to change the ecological function of an
area to achieve desired ecosystem goods and services from
a site. Land manager observations can provide information
about how a site was transformed e.g. what, where and when
an intervention/s was/were used and what was the observed
result.
Expert elicitation can be used to evaluate expected and
observed outcomes of land manager practices; including those
outcomes which were inadvertent.
A VAST-2 handbook (Thackway 2014) assists practitioners
compile historical and contemporary information on the
responses of native plant communities at sites to the impacts
of land use and land management practices over time.
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What are land management practices?
Land management practices are interventions or actions
including grazing, land clearing, weed invasions and establishing
inappropriate fire regimes. These practices are used to
remove/replace, maintain/improve, sustainably harvest/manage,
replace/manage, monitor the health, vitality and condition,
establish/rehabilitate a native plant community.
What do the completed results look like?
Figure 2 shows an example for a Themeda grassy woodland
on the southern tablelands of NSW. More results of
completed VAST-2 sites are posted on ACEAS portal
http://aceas.org.au/portal/ and the TERN Data Discovery
Portal (http://portal.tern.org.au/)
How is the issue of data quality handled?
All information compiled into a historical record for a site
using the VAST-2 system is assigned a reliability or certainty
level. This includes geospatial position, temporal accuracy and
thematic accuracy. As new and more accurate information
becomes available this replaces less reliable information in the
historical record.
Are the results of the VAST-2 system peer reviewed?
Yes. The TERN Digital Object Identifier (DOI)-minting
service is used to assign unique DOIs to completed VAST-2
datasets. This means that these datasets are citable, akin to
scholarly scientific publications like journal articles. The VAST-2
datasets are searchable via The Data Citation Index enabling
researchers to discover, use and track citation of datasets.
Tracking of dataset citation will be a key indicator of the
usefulness of that dataset to the broader research community.
What types of information can be used in VAST-2?
VAST-2 compiles and assesses qualitative observations
and quantitative measurements about land management
and their effects on vegetation and the environment. Both
published and unpublished are valuable. Oral histories,
observations (photo-points) of land managers and scientific
measurements collected at opportunistic and long-term
ecological monitoring sites are equally important. Time series
aerial photos, satellite and drone-based imagery and paddock
histories in farm journals and peer reviewed scientific journal
papers are equally important.
Figures 4, 5, 6 and 7.
Does VAST-2 establish a long-term monitoring
system?
No.VAST-2 synthesises multi-temporal and multi-spatial
information into a site-based historical record that describes
changes in the condition of a native plant community (i.e. land
diary of change and trend) over time. However,VAST-2 can
compile a diverse range of data from long term ecological
monitoring sites.
Interim Biogeographic Regionalisation for Australia
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Condition
components
(VAST diagnostic
attributes)
Attribute groups
(10)
Description of loss or gain relative to pre settlement indicator reference
(22)
SCORING SITES FOR EACH YEAR
1
Vegetation
Transformation
Index
3
(3)
10
Fire regime
1. Change in the area /size of fire foot prints
22
Soil hydrology
Diagnostic
attributes
2. Change in the number of fire starts
3. Change in the soil surface water availability.
Regenerative
Capacity
Vegetation
Structure
Species
Composition
Regenerative capacity
Soil physical state
5. Change in the depth of the A horizon
6. Change in soil structure.
Soil nutrient state
7. Nutrient stress – rundown (deficiency) relative to soil fertility
Attribute
groups
4. Change in the ground water availability
Fire
Soil
(2)
Reproductive
potential
Understorey
Overstorey
(2)
(3)
Overstorey
(3)
(2)
Understorey
(2)
8. Nutrient stress – excess (toxicity) relative to soil fertility
Soil biological
state
9. Change in the recyclers responsible for maintaining soil porosity and nutrient
recycling
Structure
Nutrients
Biology
(2)
(2)
(2)
Hydrology
(2)
Indicators
10. Change in surface organic matter, soil crusts
Reproductive
potential
11. Change in the reproductive potential of overstorey structuring species
Figure 1. Information hierarchy used to synthesize data through four levels; indicators (22), attribute groups (10), diagnostic attributes (3) and
transformation score (1).
12. Change in the reproductive potential of understorey structuring species
Overstorey
structure
13. Change in the overstorey top height (mean) of the plant community
Vegetation structure
14. Change in the overstorey projective foliage cover (mean) of the plant
community
15. Change in the overstorey structural diversity (i.e. a diversity of age classes) of
the plant community
Understorey
structure
16. Change in the understorey top height (mean) of the plant community
Species
Composition
21. Change in the densities of understorey species functional groups
22. Change in no.s of indigenous understorey species relative to the number of
exotic species
Table 1.VAST-2 hierarchy comprising components of vegetation condition, attribute groups and indicators of
vegetation transformation. Numbers in brackets refer to the triangle in Figure 1.
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Step 1a
Step 3a
Use a checklist of 22 indicators to compile
changes in LU & LMP and plant
community responses over time
Literature review to determine the
baseline conditions 22 indicators
Step 2
Step 1b
Derive the responses of
all 22 indicators
Step 4
Derive the reference
states for 22 indicators
Evaluate the influence of climate, soil and
landform on the historical record
Step 1c
Synthesise and evaluate transformation
of plant community using 22 indicators
Step 3b
Evaluate the influence or climate, soil
and landform for the reference site
Step 5
Score all 22 indicators for ʻtransormation siteʼ relative to the
ʻreference siteʼ. 0 = major change; 1 = no change
Step 3c
Compile indicator data for 22
indicators for reference site
19. Change in the densities of overstorey species functional groups
20. Change in no.s of indigenous overstorey species relative to the number of exotic
species
Understorey
composition
reference state/site
17. Change in the understorey ground cover (mean) of the plant community
18. Change in the understorey structural diversity (i.e. a diversity of age classes) of
the plant
Overstorey
composition
transformation site
Step 6
Derive weighted indices for the three components for the ʻtransformation
siteʼ i.e. regenerative capacity (58%), vegetation structure (27%) and
species composition (18%) by adding predefined indicators
Step 7
Add the indices for the three components to generate total transformation
index for the ʻtransformation siteʼ for each year of the historical record.
Validate using Expert Knowledge
Figure 2. General process for tracking changes in vegetation condition over time.
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Cumberland State Forest
Legend
Fauna
Compartments
State Forest Boundary
Roads and Tracks
Fire Trail (4WD)
Road (2WD)
Walking Track
2m Contours
Drainage
100m Grid
Forest Type
Dry Blackbutt
Dry Blackbutt, Turpentine
Dry Blackbutt, Sydney Blue Gum
Forest Red Gum, Grey Gum, Grey Ironbark
Forest Plantations
Grey Gum Ironbark, Sydney Blue Gum
Sydney Blue Gum
Turpentine
Figure 5. Map of the vegetation types for Cumberland State Forest.T1 and T2 shows the location of the site-based transects (figure 6).
On-ground field survey 2012
Figure 3. Example of VASTTRANS scores for a Themeda grassy woodland, 34°58’1.12”S,,149°10’39.62”E, Murrumbateman, NSW.VASTTRANS
scores are calibrated to Vegetation Assets, States, and Transitions (VAST) classes i.e. coloured boxes.
Examples of some of the information
that is compiled and evaluated to
determine change over time.
SITE 2
SITE 1
Transect 1
Cumberland SF, ex-compartments: 8b, 9a, 9b.
Regrowth forest
Figure 4. Shows aerial photos and satellite imagery for Cumberland State Forest for the period 1941-2012 in relation to the map of
forest management coupes.
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Transect 2
Cumberland SF, ex-compartments: 3a, 7a, 7b, 7c.
Repurposed arboretum
Figure 6. Site-based survey to collect data on vegetation structure, species composition and regenerative capacity.
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VAST class I: Unmodified (reference)
Further reading
Land use: minimal use
Management practices: protection, no grazing
Strata: multiple with some emergent
Biomass: 120 t/ha
Projected foliage cover: 52%
ACLUMP (Australian Collaborative Land Use and Management Program), (2010a). Land Use and Land Management Information for Australia:
Workplan of the Australian Collaborative Land Use and Management Program. Australian Bureau of Agricultural and Resource Economics
and Sciences, Canberra. http://adl.brs.gov.au/data/warehouse/pe abares99001769/ACLUMP WorkplanReport 20101216.pdf [accessed on 8
December 2012].
Maximum height: 24 m
Species per strata: over 3–5, mid 5+, ground 5–10
Regeneration: very good
ACLUMP (Australian Collaborative Land Use and Management Program), (2010b). Status of Land Management practices Activities of the
Australian Collaborative Land Use and Management Program. Australian Bureau of Agricultural and Resource Economics and Sciences,
Canberra. http://adl.brs.gov.au/data/warehouse/pe abares99001770/ACLUMP StatusReport 20101216.pdf [accessed on 8 December 2012].
Terrestrial Ecosystem Research Network (TERN), (2012a). Tracking the transformation of vegetated landscapes. eNewsletter-2012-Aug. http://
www.tern.org.au/Newsletter-2012-Aug-ACEASThackwayHandbook-pg23202.html [accessed on 8 December 2012].
VAST class II: Modified
Land use: grazing native vegetation
Management practices: ringbarking and grazing
Strata: two normal height
Biomass: 68 t/ha
Projected foliage cover: 25%
Maximum height: 17 m
Species per strata: over 3, mid 1, ground 1–4
Regeneration: low to moderate
Terrestrial Ecosystem Research Network (TERN), (2012b). Enabling and encouraging dataset citation:TERN’s DOI-minting service.TERN e-Newsletter
October 2012. http://www.tern.org.au/newsletter-2012-Oct-DOI-pg24032.html [accessed on 8 December 2012].
Terrestrial Ecosystem Research Network (TERN), (2012c).Vegetation transformation. Data discovery portal (Beta). http://portal. tern.org.au/
search#%21/q=%28vegetation%20transformation%29/p=1/tab=collection/num=10 [accessed on 8 December 2012]
Thackway, R., (2013). Applying a system for tracking the changes in vegetation condition to Australia’s forests. In: Brown, A.G., Wells, K.F., Parsons,
M. and Kerruish, C.M. (eds) (2013) Managing our Forests into the 21st Century. Proceedings of national conference, Institute of Foresters of
Australia, Canberra, ACT, Australia, 4–7 April 2013, pp. 79-91.
http://forestryconference.org.au/program/program-abstracts/ifa-2013-conf-papers-thackway
Thackway, R. (2014).VAST-2 Tracking the Transformation of Vegetated Landscapes, Handbook for recording site-based effects of land use and
land management practices on the condition of native plant communities,Version 3.0, June 2014. Australian Centre for Ecological Analysis and
Synthesis, Terrestrial Ecosystem Research Network. Brisbane: The University of Queensland; 2014 p. 35.
Thackway, R. and Lesslie, R., (2006). Reporting vegetation condition using the Vegetation Assets, States, and Transitions (VAST) framework.
Ecological Management and Restoration. 7(Suppl. 1):53-62. [abstract at doi/10.1111/j.1442-8903.2006.00292.x] [accessed on 8 December 2012].
VAST class III: Transformed
Land use: grazing native vegetation
Thackway,R., and Lesslie,R., (2008).Describing and mapping human-induced vegetation change in the Australian landscape. Environmental
Management 42, 572–590. [abstract at dx.doi.org/10.1007/s00267-008-9131-5] [accessed on 8 December 2012].
Management practices: mechanical tree removal and grazing
Strata: single – low height
Thackway ,R. and Specht, A., (2015). Synthesising the effects of land use on natural and managed landscapes. Science of the Total Environment.
526:136–152 doi:10.1016/j.scitotenv.2015.04.070.
Biomass: 42 t/ha
Trudgill, S. T. (1988). Soil and vegetation systems. Clarendon Press, Oxford. p 211.
Projected foliage cover: 20%
Maximum height: 13 m
Species per strata: over 3, mid 0, ground 1–4
Regeneration: very low with bare ground
Yapp, GA. and Thackway, R. (2015). Responding to Change — Criteria and Indicators for Managing the Transformation of Vegetated Landscapes
to Maintain or Restore Ecosystem Diversity. In: Biodiversity in Ecosystems - Linking Structure and Function, Dr Juan A. Blanco (Ed.), ISBN: 978953-51-2028-5, InTech, Available from: http://www.intechopen.com/books/biodiversity-in-ecosystems-linking-structure-and-function/responding-to-change-criteria-and-indicators-for-managing-the-transformation-of-vegetated-landscapes
Figure 5. Classes of native vegetation condition classified using VAST (Thackway and Lesslie 2006, 2008)
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transformations
Richard Thackway
www.vasttransformations.com
[email protected]
0426 258 361
VAST Transformations © 2015