tracking the effects of land use and management on vegetation condition

Tracking the effects of land use and management on vegetation condition

Richard Thackway

Presentation to NSW OEH6 March 2013

Outline

• Concepts and definitions• Background to VAST framework• Why VAST-2 was developed• VAST-2 methodology • Case studies• Lessons • Where to here?• More information

Goals of land managers

Changes in ecological function

Values and decisions matrix:• Social• Economic• Environmental

Intensification

Degradation?

Goals of land managers

Changes in ecological function

Values and decisions matrix:• Social• Economic• Environmental

Extensification

Restoration

Regulation of hydrological regime Generation of food and fibre Regulation of climate / microclimate Generation of raw materials Recycling of organic matter Creating and regulating habitats Controlling reproduction and dispersal

Changing ecological function to derive multiple benefits (ecosystem services)

Drivers for information on changes in vegetation condition

• NRM policy and program design e.g.

– Implementing guidelines for conservation and management of threatened species

EPBC ACT

– Reporting on the performance of investment e.g. changing LMP to improve

landscape connectivity

– Assessing land acquisitions for the National Reserve System

• Resource condition of native vegetation e.g.

– A measure of sustainable use and management (public & private)

• Monitoring and reporting and improvement e.g.

– National, state & regional reporting e.g. SoE & SOFR

– Reporting 5 yearly outcomes Regional Forest Agreements

What is condition and transformation?

• Changes to a plant community caused by landuse

/management

– Structure

– Composition

– Regenerative capacity

• Transformation = changes to vegetation condition over time

• Condition and transformation are relative to a reference state

Vegetation condition

Vegetation Assets States and Transitions (VAST) framework

VIVIVIIIIII0

Native vegetationcover

Non-native vegetationcover

Increasing vegetation modification from unmodified state

Transitions = trend

Vegetation thresholds

Reference for each veg type (NVIS)

VAST - A framework for compiling & reporting vegetation condition

Condition states

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

Why VAST-2 was developed?

• To implement the ‘T’ (Transition) of the VAST framework– i.e. track changes in vegetation condition over time

• To provide a practical tool for understanding and reporting the status of native vegetation over time

• To propose a standardised national system for compiling data on cause & effect of management on native plant communities

VAST – a snapshot

Thackway & Lesslie (2008) Environmental Management, 42, 572-90

NB: Input dataset biophysical naturalness reclassified using VAST framework

Models of ecosystem change

Source: Adamson and Fox (1982).

Time

Chan

ge in

veg

etati

on in

dica

tor

Settlement

10000

Reference

Occupation

Relaxation

Anthropogenic change

Net impact

Time

1800 1850 1900 1950 2000

Based on Hamilton, Brown & Nolan 2008. FWPA PRO7.1050. pg 18Land use impacts on biodiversity and Life Cycle Analysis

Reference

Models of ecosystem changeCh

ange

in v

eget

ation

indi

cato

r

Aim of VAST-2

Indigenous land management

First explorers

Grazing

Deg

ree

of

mod

ifica

tion

Logging

Cropping

Site 1

Site 2

Site 3

Time

Reference state

Long term rainfall

Long term disturbance e.g. wildfire, cyclones

Revegetation

VAST classes

VAST-2 System

Condition components

(3)

Attribute groups

(10)Description of loss or gain relative to pre settlement indicator reference state

(22)

Regenerative

capacity

Fire regime Area /size of fire foot prints

Number of fire starts

Soil hydrology Soil surface water availability

Ground water availability

Soil physical state

Depth of the A horizon

Soil structure

Soil nutrient state

Nutrient stress – rundown (deficiency) relative to soil fertility

Nutrient stress – excess (toxicity) relative to soil fertility

Soil biological state

Recyclers responsible for maintaining soil porosity and nutrient recycling

Surface organic matter, soil crusts

Reproductive potential

Reproductive potential of overstorey structuring species

Reproductive potential of understorey structuring species

Vegetation structure

Overstorey structure

Overstorey top height (mean) of the plant community

Overstorey foliage projective cover (mean) of the plant community

Overstorey structural diversity (i.e. a diversity of age classes) of the stand

Understorey structure

Understorey top height (mean) of the plant community

Understorey ground cover (mean) of the plant community

Understorey structural diversity (i.e. a diversity of age classes) of the plant

Species Compositi

on

Overstorey composition

Densities of overstorey species functional groups

Relative number of overstorey species (richness) of indigenous to exotic species

Understorey composition

Densities of understorey species functional groups

Relative number of understorey species (richness) of indigenous to exotic species

Step 7Add the indices for the three components to generate total transformation

index for the ‘transformation site’ for each year of the historical record . Validate using Expert Knowledge

Step 1aUse a checklist of 22 indicators to compile

changes in LU & LMP* and plant community responses over time

Transformation site

Step 1cEvaluate impacts on the plant community

over time

Step 1bEvaluate the influence of climate, soil and

landform on the historical record

Step 2Document responses of 22

indicators over time

Step 4Document the reference states for 22 indicators

Step 3aLiterature review to determine the

baseline conditions for 22 indicators

Step 3cCompile indicator data for 22 indicators for reference site

Step 3bEvaluate the influence of climate, soil and landform for the reference site

Reference state/sites

Step 5Score all 22 indicators for ‘transformation site’ relative to the

‘reference site’. 0 = major change; 1 = no change

Step 6Derive weighted indices for the three components for the ‘transformation

site’ i.e. regenerative capacity (58%), vegetation structure (27%) and species composition (18%) by adding predefined indicators

General process for tracking changes VAST-2 system

* LU Land useLMP Land management practices

Method: VAST-2

Species

composition

LU = Land Use, LMP = Land Management Practices

Indicators of VAST diagnostic attributes

LU & LMPYear

Time

Vegetation structure Regenerative

capacity

Year Source Year and reliability

LU & LMP Source: LU & LMP

Reliability of LMP

sources and spatial

accuracy

Effects of use and land management practices on

structure, composition and function

SourceEffects

Reliability of effects

and spatial accuracy

1800

1840

2013

Pre-contact

First contact

Current year

LU = Land Use, LMP = Land Management Practices

Method: VAST-2

Scoring impacts of land management practices

• All management practices are directed at e.g.– Vegetation/plants, soil, landform, water, animal, air

• Five objectives summarize all vegetation management– Establish and rehabilitate– Improve and maintain growth and condition– Harvest plant products and remove waste and weeds – Monitor health, vitality and condition– No activity or interventions

• Combinations of 5 objectives are common (space & time)• Impacts of LMP are scored for each VAST-2 indicator relative

to indicator’s reference state for each year

1

3

10

22

Dia

gnos

ticatt

ribut

es

VegetationTransformation

score

Attrib

ute

grou

ps

VegetationStructure

(27%)

Overstorey

(3)

Understorey

(3)

SpeciesComposition

(18%)

(2)

UnderstoreyOverstorey

(2)

RegenerativeCapacity

(55%)

Fire

(2)

Reprodpotent

(2)

Soil

Hydrology

(2)

Biology

(2)

Nutrients

(2)

Structure

(2) Indicators

VAST-2 hierarchy

Certainty level standards used to compile historic record

Certainty level standards

Spatial precision(Scale)

Temporal precision(Year of observation)

Attribute accuracy(Land use, land

management practices, effects on condition)

HIGH "Definite”

Reliable direct quantitative data.

Code: 1


Code: 4


Code: 7

MEDIUM "Probable

"

Direct (with qualifications) or strong

indirect data.

Code: 2


indirect data.

Code: 5


indirect data.

Code: 8

LOW "Possible"

Limited qualitative and possibly contradictory

observations. More data needed.

Code: 3



Code: 6



Code: 9

Reliability levels of attribute information

Quadrat or pixel

Land unit

Land system

Sub-bioregion

Bioregion

Certainty levels

Coarse

Fine

Low

Low

Medium

Medium

High

Sources of information

Granularity of information

Case studies VAST-2

Cumberland State Forest 1941-2012

Red boundary shows main compartments that were cleared as per the 1943 aerial photograph. This area was fully planted out around 1944 as part of the arboretum. Except for regrowth forests: i.e. compartments 8a, 9a, 9b and 10b

T1

T2

On-ground field survey 2012

Transect 1Cumberland SF, ex-comp 8b, 9a, 9b.Regrowth forest

Transect 2Cumberland SF, ex-comp 3a, 7a, 7b, 7c.Repurposed arboretum

On-ground field survey 2012

VAST Unmodified

NSW, SB Bioregion, Cumberland SF, ex-comp 3a, 7a, 7b, 7cReference pre-European: Sydney Blue Gum High Forest

Commenced managing area for recreation. Weed control. Arboretum abandoned

Cleared & sown to improved pasture for grazing & orchard

Commenced grazing native pastures

Indigenous people manage the area

Area gazetted as State Forest, commenced planting arboretum

Area logged for building houses and fences

Commenced managing area as a future production forest. Weed control

Explorers traverse the area and site selected

Ceased grazing. Area purchased as a future working forest

VAST Unmodified

Commenced managing area primarily for recreation

Ceased grazing. Purchased & declared as a State forest

Site fenced. Commenced continuous stocking with cattle

Commenced grazing cattle

Indigenous people manage the area

Cleared and commenced regrowing forest as a future forest production

Tree cover thinned for cattle grazing

Initiated 1st hazard reduction burn

Trees logged for housing, fences & fire wood

NSW, SB Bioregion, Cumberland SF, ex-comp 8b, 9a, 9b Reference pre-European: Sydney Blue Gum High Forest

• Network of collaborators• Ecologists, academics, land managers, environmental historians,

educators

• Inputs• Reference state • Land use• Land management practices• Natural events e.g. droughts, fires, floods, cyclones, average rainfall

1900-2012 etc• Observed interactions e.g. rabbits, sheep and drought• Observations and quantitative measures of effects

• Include written, oral, artistic, photographic and remote sensing

Resources needed to compile and analyse an historical record for each site

VAST-2 Lessons

• Useful tool for:• engaging a wide range of collaborators and stakeholders incl:

• ecologists, academics, land managers, environmental historians, educators because it builds on VAST, which is widely accepted and used

• synthesizing information and ‘telling the story’ of vegetation transformation since settlement

• reporting ‘telling the story’ progress toward vegetation condition targets • Understanding resilience of natural ecosystems

http://portal.tern.org.au/transformation-of-australias-vegetated-landscapes-cumberland-state-forest-recommissioned-regrowth-forest-nsw

http://aceas-data.science.uq.edu.au/portal/

Where to from here?

• Scaling-up to landscape levels• More sites • Transfer and adoption

Scaling up to landscape levels Static layers

•first contact by European explorers•slope & relief derived from 30m DEM•aspect classes derived from 30m DEM•weathering layer•digital atlas of soils+•pre-European vegetation types (NVIS)

Time series response variables•rainfall anomaly (post 1900)•state-wide & national land tenure•FPC (post 1980s)*•ground cover (post 1980s)*•NDVI / EVI (post 1980s)*•native veg (tree) layers*•state-wide & national land use

• sheep DSE• cattle DSE• cropping• urban areas• Plantations• nature conservation reserves• indigenous protected areas

•Infrastructure• railways• roads

•fire regime (fire area & No. fire starts)*•otherTERN AusCover*

TERN Soils+

Landform Pattern and Topographic Position Index. 30 m – DEM SRTM

Nass Valley - ACT

Further information

• VAST-2 Handbook and brochure http://www.vasttransformations.com/

http://www.vasttransformations.com/

tracking the effects of land use and management on vegetation condition

Education