Contacts

Identifiers and Keywords

ANZLIC Id

ANZVI0803005066 

Jurisdiction

Victoria 

Topic category

• Biota

Resource Constraints

Use limitation

General access. Email request to: data.vsdl@dse.vic.gov.au to access this Grid dataset. 

Classification

Limited Distribution  

Other Dataset Details

Date ( Revision )

2021-08-27

Status

Obsolete  

Purpose

To contribute to assessments of the significance of native vegetation at different locations, and of the amount of potential loss or gain. 

Credit

Dataset Creators: Graeme Newell, Matt White & the Native Vegetation Review Team 

Format

TIFF format 2 

Supplemental Information

Future Design Issues: None Proposed Related Documents: None 

Maintenance and update frequency

As needed  

Spatial

Spatial representation type

Grid  

Description

General - Victoria 

Reference system identifier

4283

N

S

E

W

Temporal

Begin date

2013-04-01 

End date

2013-09-27 

Resolution

Horizontal Accuracy

25m  

Quality

Missing Data

Victoria 

Excess Data

Continuous grid attributes of 0-100 where 100 is the highest site condition and 0 is the lowest. The data is continuous and linear. Note that condition scores are from 0.01 to 1.00, but this is more readily represented in the spatial model as 0-100. 

Attribute Quality

This dataset is a model and as such is an indication of likely native vegetation condition. It would be improved by additional stratified and systematic collection of primary data including species diversity and cover. 

Positional Accuracy

75x75m cells 

Lineage

Description

Condition benchmarks for each lifeform in each vegetation type were modelled separately for diversity and cover using data from 40,000 accurately located vegetation plots from known high condition sites, and coincident environmental predictors. Current condition at a site was calculated by comparing the diversity and cover of each lifeform that was observed at each site with the modelled benchmark. An overall score for 'lifeform diversity' and 'lifeform cover' at each site was obtained by aggregating the lifeform proportions. Each proportion was first weighted according to the contribution of each lifeform to the total diversity and total overlapping cover of the benchmark. These aggregate composition (diversity) and structure (cover) scores were then modelled across the state using a wide range of environmental predictors including climate terrain, soils, land use, satellite imagery and other variables that are indicative of human disturbance. A single condition model was built by combining the resultant models for structural and compositional condition using the geometric mean of the two layers at every 75 m pixel. Finally, in order to consider the effect of landscape context, a smoothing routine was run over the data which was weighted by distance from the centre cell. This had the effect of slightly increasing the score of good condition sites surrounded by other good condition sites and slightly reducing the score of bad condition sites surrounded by other bad condition sites. The routine was restricted so that sites at greater than 300 m away had a negligible effect. 

Statement

Dataset Source: The vegetation condition model is based on generating a frame of reference (benchmarks), generating the current condition by calculating how the observed condition deviates from the benchmark, and modelling the current condition across the landscape. There are two primary data sources are Vegetation plots (50,000+ sites) and Habitat Hectares (20,000+ sites). Dataset Originality: Primary & Derived 

About the Metadata Record

Metadata identifier

urn:uuid / 5de93d6b-84ba-55c1-91b5-12d1226ae299