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Cape York Peninsula Land Use Strategy

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Key departmental publications, e.g. annual reports, budget papers and program guidelines are available in our online archive.

Much of the material listed on these archived web pages has been superseded, or served a particular purpose at a particular time. It may contain references to activities or policies that have no current application. Many archived documents may link to web pages that have moved or no longer exist, or may refer to other documents that are no longer available.

Areas of Conservation Significance on Cape York Peninsula

Cape York Peninsula Land Use Strategy
Abrahams, H., Mulvaney, M., Glasco, D., & Bugg, A.
Office of the Co-ordinator General of Queensland
Australian Heritage Commission, March 1995


Areas of Conservation Significance on Cape York Peninsula

Appendix 3 Rare and Uncommon Vegetation Communities. Threshold determination and results.

The analysis of rare and uncommon vegetation communities across the region is outlined in Section 4 of the report. This appendix details the thresholds and their derivation and results of the analysis.

Determination of Rare, and Uncommon communities was undertaken at two mapping scales. One using Broad Vegetation Groups (BVG's) and another using the 201 Vegetation Classes both obtainable from the Neldner, Clarkson vegetation mapping. The scale of mapping is important in any map unit based analysis, by doing the analysis at two scales it is possible to effectively test the sensitivity of the analysis to scale issues. The detailed rule set for determining Rare and Uncommon are as follows.

Broad Vegetation Groups (BVG).

Aim: To determine rare and uncommon status on the basis of BVG's and the area of the Peninsula occupied by each BVG. (See Table A3.1).

Thresholds: Rare =< 0.75% (approx 100,000 ha) of the total CYPLUS study area.

Uncommon =< 2% (approx 200,000 ha) of the total CYPLUS study area

(The determination of the thresholds was data-driven and equated with clear break points in the distribution of the areas of the Broad Vegetation Groups).

Result: A total of 13.23% of the Peninsula was determined to contain Rare (R=3.29%) or uncommon communities (U=9.94%).

201 Vegetation Classes

Using the 201 vegetation categories thresholds for rare and uncommon classes were determined on the basis of both total area and total polygon frequency. Those communities with a lower polygon frequency being restricted. Table A3.2 incorporates consideration of rare, uncommon, restricted, and limited communities as outlined following.

Area

Thresholds: Rare < 0.05% (approx 6000 ha) of the total CYPLUS study area.

Uncommon <0.08% (approx 10,000 ha) of the total CYPLUS study area.

(Again the determination of the categories was data-driven).

Polygon Frequency

Thresholds: Restricted = Vegetation class occurs in less than 30 polygons within the study area.

Limited = Vegetation class occurs in less than 60 polygons within the study area.

(The determination of the thresholds was data-driven. There are approx. 17,000 vegetation polygons mapped across the Peninsula).

To classify communities at the 201 vegetation class level as rare, uncommon or common the area and frequency analyses were combined as below.

Rare Rare by area analysis, or

Restricted by frequency analysis, or

Both Uncommon and Limited.

Uncommon Uncommon by Area Analysis, or

Limited by Frequency analysis.

Common Neither Rare nor Uncommon as above.