Tracking the
Transformation
of Vegetated
Landscapes
using the
VAST-2 system
RICHARD
THACKWAY
VAST Transformations 2012
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 land-management 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. The
absence of a consistent approach to reporting transformations of plant
communities over space and time remains a source of contention – and
even conflict – between those involved in conservation and protection,
and those responsible for sustainable land use and management.
The VAST-2 system
VAST-2 addresses several key questions: –
•
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 and 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.
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.
1
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.
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
approach relevant to Australia’s tropical, sub-tropical,
arid, semi-arid, and temperate bioregions.
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 enables ecologists and
land managers to explore options for future use and
management of the site. As a historical record this
information is also useful for environmental planners,
educators, historians, industry groups and
the wider public.
What are the benefits of the VAST-2 system for decision makers?
VAST-2:
•
empowers land managers to engage equally with ecologists 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
•
enables observational, qualitative and quantitative data/information to be synthesised to create a historical narrative which is analysed using 22 indicators
•
illustrates complex ecological patterns and processes using simple to understand graphical tools
•
highlights options and future trade-offs for decision-makers
Frequently asked questions
What is vegetation condition?
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).
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
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 local
acknoledged ecologists are engaged to evaluate the
historical record of land managers and the reported
effects of land management practices on vegetation
indicators at a site. Ecologists and land managers
together contribute valuable ecological insights; and
together they validate the final indicator scores and
transformation indices.
What observations do land managers make?
Land manager observations often document the
outcome of economic decisions relating to the
effectiveness of their land management decisions;
what, where and when i.e. did the planned intervention
produce the expected result. Land managers can
regard native vegetation as a means to an end i.e.
profit and loss. In other settings, land managers
invest to change the ecological function of an area
to achieve a desired ecosystem good or service from
a site. The 22 indicators can be used to evaluate
expected and observed outcomes of land manager
decisions. A handbook (Thackway 2012) has been
developed to assist 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.
Why does VAST-2 use a bioregional approach?
Establishing a 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-IBRA 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 use indicators describe to describe response and
change?
The 22 indicators describe the response variable 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).
Does VAST-2 establish a monitoring system?
No. VAST-2 synthesises multi-temporal and multi-spatial
information into a spatiotemporal site-based historical
record describing the transformation of a native plant
community (i.e. land diary of change and trend).
However, VAST-2 can compile a diverse range of data
from long term ecological monitoring sites.
2
VAST Transformations 2012
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.
FAQ continued...
What is the difference between VAST and VAST-2?
VAST-2 was developed out of a need to implement a
system to routinely report changes in condition states
over time. It represents an enhancement of the VAST
(Vegetation Assets, States and Transitions) framework
(Thackway and Lesslie 2006, 2008) in that it provides
a system for routinely tracking the causes of transitions
between condition states.
How is the issue of data quality handled?
All information compiled into a historical record for a
VAST-2 site 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 information
in the historical record.
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. A
transformation index is calculated by aggregating the
22 indicators and three components for each year of
the historical record.
What are land management practices?
Land management interventions or actions include
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 is a historical record?
A historical record comprises information about the
management of a site from the point of first contact and
includes contemporary measurements and observations
where these are available.
3
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 imagery
and paddock histories in farm journals and peer
reviewed scientific journal papers are equally important.
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
and area. The dimensions of the site remain constant
back in time, now and into the future. A site is a
representative plant community or land unit. The land
use and land management of the site may change over
time. VAST-2 system records these practices and their
effects at the site over time.
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/
Are the results of the VAST-2 system peer reviewed?
The TERN Digital Object Identifier (DOI)-minting service
has been 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.
SCORING SITES FOR EACH YEAR
1
Vegetation
Transformation
Index
3
10
Attribute
groups
Diagnostic
attributes
22
Regenerative
Capacity
Fire
Soil
Vegetation
Structure
Reproductive
potential
(2)
Structure
(2)
Understorey
Overstorey
(2)
(3)
Nutrients
Biology
(2)
(2)
Species
Composition
Understorey
Overstorey
(3)
(2)
(2)
Hydrology
(2)
Indicators
Figure 1. Information hierarchy used to synthesize data through four levels; indicators (22), attribute groups (10), diagnostic
attributes (3) and transformation score (1).
Regenerative capacity (55%)
Vegetation structure (27%)
60%
30%
50%
Unmodified
25%
Unmodified
40%
Modified
20%
Modified
30%
Transformed
15%
Transformed
20%
Replaced/
adventive
10%
Replaced/
adventive
10%
Removed/
replaced/
managed
0%
1750
1800
1850
1900
1950
2000
2050
5%
Removed/
replaced/
managed
0%
1750
Species composition (18%)
1800
1850
1900
1950
2000
2050
Total Vegetation Transformation Index (100%)
20%
120%
18%
Unmodified
16%
14%
12%
10%
8%
6%
4%
Modified
80%
Transformed
60%
Replaced/
adventive
40%
Removed/
replaced/
managed
2%
0%
1750
1800
1850
1900
1950
2000
2050
100%
Unmodified
Modified
Transformed
Replaced/
adventive
20%
0%
1750
1800
1850
1900
1950
2000
2050
Removed/
replaced/
managed
Figure 2. 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.
4
VAST Transformations 2012
Condition
components
(VAST
diagnostic
attributes)
Attribute groups
(10)
Description of loss or gain relative to pre settlement indicator reference
(22)
(3)
Fire regime
Soil hydrology
Regenerative capacity
Soil physical
state
Soil nutrient
state
Soil biological
state
Reproductive
potential
Vegetation structure
Overstorey
structure
Understorey
structure
Species
Composition
Overstorey
composition
Understorey
composition
1.
2.
3.
4.
5.
6.
7.
8.
9.
Change in the area /size of fire foot prints
Change in the number of fire starts
Change in the soil surface water availability.
Change in the ground water availability
Change in the depth of the A horizon
Change in soil structure.
Nutrient stress – rundown (deficiency) relative to soil fertility
Nutrient stress – excess (toxicity) relative to soil fertility
Change in the recyclers responsible for maintaining soil porosity and
nutrient recycling
10.Change in surface organic matter, soil crusts
11. Change in the reproductive potential of overstorey structuring species
12.Change in the reproductive potential of understorey structuring species
13.Change in the overstorey top height (mean) of the plant community
14.Change in the overstorey foliage projective cover (mean) of the plant
community
15.Change in the overstorey structural diversity (i.e. a diversity of age
classes) of the plant community
16.Change in the understorey top height (mean) of the plant community
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
19.Change in the densities of overstorey species functional groups
20.Change in the relative number of overstorey species (richness) of the
plant community
21.Change in the densities of understorey species functional groups
22.Change in the relative number of understorey species (richness) of the
plant community
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.
5
A. Reference: unmodified
Land use: minimal use
Management practices: protection, no grazing
Strata: multiple with some emergent
Biomass: 120 t/ha
Projected foliage cover: 52%
Maximum height: 24 m
Species per strata: over 3–5, mid 5+, ground 5–10
Regeneration: very good
B. 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
C. Transformed
Land use: grazing native vegetation
Management practices: mechanical tree removal
and grazing
Strata: single – low height
Biomass: 42 t/ha
Projected foliage cover: 20%
Maximum height: 13 m
Species per strata: over 3, mid 0, ground 1–4
Regeneration: very low with bare ground
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Further reading
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].
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-2012Aug. http://www.tern.org.au/Newsletter-2012-Aug-ACEASThackwayHandbook-pg23202.html [accessed on 8 December 2012].
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. (2012). 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 2.3, October 2012. Westerlund Eco
Services, Rockingham, Western Australia, p56. http://www.vasttransformations.com/ [accessed on 8 December 2012].
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].
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].
Trudgill, S. T. (1988). Soil and vegetation systems. Clarendon Press, Oxford. p 211.
transformations
Richard Thackway
www.vasttransformations.com
[email protected]
0426 258 361
VAST Transformations © 2012