Identification, Assessment and Protection of National Estate Part a natural Values



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3. Extensive natural values

The two criteria of relevance to the assessment of extensive natural values are:



National Estate Criterion A.2— ‘importance in maintaining existing processes or natural systems at the regional or national scale’, and

National Estate Criterion B.1— ‘importance for rare, endangered or uncommon flora, fauna, communities, ecosystems, natural landscapes or phenomena, or as a wilderness’.

These are inclusive values, extending broadly across the landscape rather than being confined to single vegetation types, landforms or localities. The values considered in this aspect of the lower north-east assessment are:




  • natural landscapes;

  • undisturbed catchments;

  • wilderness; and

  • old-growth forest.

Assessment of these values resulted in the identification of indicative places of importance for the maintenance of natural processes (such as hydrological processes) at regional and national scales, and places that are of regional importance for maintaining specific natural systems (such as remnant vegetation).



3.1 Wilderness


The assessment of wilderness in the Lower North-East comprehensive regional assessment region of New South Wales utilised the Commonwealth’s National Wilderness Inventory methodology, developed by the Australian Heritage Commission, as specified under JANIS. The NSW Wilderness Act was not used in the LNE CRA Wilderness Assessment.
The assessment, identification, declaration and management of wilderness in New South Wales (outside of the CRA process) are principally guided by the New South Wales Wilderness Act 1997. The criteria for identification of Wilderness under the Wilderness Act are consistent with the National Forest Policy Statement definition of wilderness. The National Forest Policy Statement does, however, define wilderness as being remote from the influences of European settlement whereas the Act uses recovery potential as a criterion.

3.1.1 Method

The National Wilderness Inventory methodology is the adopted standard approach to the assessment of wilderness in Regional Forest Agreements throughout Australia. While a dual identification approach was undertaken in Upper North-East, protection requirements in the Regional Forest Agreement process are linked solely to the National Wilderness Inventory. The nationally agreed criteria stipulates that, Ninety percent, or more if practicable, of the area of high quality wilderness that meets minimum area requirements should be protected in reserves (JANIS 1997, p.15).

The National Wilderness Inventory is a geographic information system, which measures remote and natural values to produce a ‘Wilderness Quality’ continuum. The National Wilderness Inventory Wilderness Quality is produced from four disturbance indicators, each weighted equally:


  • Remoteness from Access;

  • Remoteness from Settlement;

  • Apparent Naturalness; and

  • Biophysical Naturalness.

Each of these indicators is individually updated with the best available data and then combined to measure the Wilderness Quality of an area (see Lesslie and Maslen 1995). The indicators are derived from the definition of wilderness quality as the extent to which a location is remote from and undisturbed by the influence of modern technological society. These indicators are:




  • Remoteness from Settlement

remoteness from places of permanent occupation;

  • Remoteness from Access

remoteness from established access routes;

  • Apparent Naturalness

the degree to which the landscape is free from the presence of permanent structures associated with modern technological society; and

  • Biophysical Naturalness

the degree to which the natural environment is free from biophysical

disturbance caused by the influence of modern technological society.


For each of the three distance-based wilderness indicators, primary data is graded according to its associated impact. The Remoteness from Access and Remoteness from Settlement indicators utilise four categories or grades of impact, whilst three grades are used in determining Apparent Naturalness. Minimum standardised distances are classified to produce consistent Remoteness from Settlement, Remoteness from Access, and Apparent Naturalness classes, with values of 0 to 5.
Biophysical naturalness

The fourth indicator, Biophysical Naturalness (BN), is based upon the assumption that the degree of change sustained by an ecosystem is directly related to the intensity and duration of interference. For the National Wilderness Inventory, land use considerations are generally restricted to the grazing of stock and the harvesting of timber. However, where data that is more reliable is available, information on a range of other disturbances is also included. The types of disturbance data typically used to derive the BN layer includes information on:




  • timber harvesting records;

  • regional information on grazing;

  • air photo interpretation;

  • land tenure;

  • grazing leases;

  • vegetation communities; and

  • mining sites.

In the biophysical naturalness rating scheme, wildfire is considered a natural process, so that areas affected by wildfire can still be given a high biophysical naturalness rating (ie. 5), unless other disturbances resulted in a lower rating. The rating scheme for BN used in the National Wilderness Inventory is outlined in Table 1. This rating system is for the ‘baseline National Wilderness Inventory’ and each region has its own rating system applied in consultation with stakeholders.


Table 1: Biophysical Naturalness Rating Scheme


Indicator Value

National Wilderness Inventory Description

for Baseline National Wilderness Inventory



5 High

Unlogged and ungrazed

4

Unlogged and ungrazed for at least 60* years; excluding clear-felled and intensively grazed areas

3

Selective single logging; irregular grazing within preceding 60* years

2

Light / Moderate grazing; repeated selective logging within preceding 60* years

1 Low

Clear-fell logging operations and / or intensive grazing

0

Agricultural, urban and developed land, pine and other exotic plantations, reservoirs.

* threshold period may vary between regions


The rating scheme adopted for upgrading the BN indicator to assess wilderness values, in the Upper North-East region is shown in Table 2 (Commonwealth and National Parks and Wildlife Service 1997).
TABLE 2: Biophysical naturalness rating scheme applied to LNE NSW


Indicator Value

NWI Description for Lower North East regional update

5 High

No evident disturbance from grazing or logging; natural water bodies; API code of “nil disturbance”.

4

Non-intensive disturbance in Rainforest *; unmapped logging events with no API evidence of disturbance; other forest management events considered to have made minimal impact.

3

Grazing lease (SF only) with pasture grasses present; weeds present, some evidence of logging from API and associated evidence from logging records.

2

Intensive record of disturbance in Rainforest *; some multiple logging records, evidence of logging from API.

1 Low

Multiple, recent and intensive logging records with evidence of disturbance in API.

0

Agricultural, urban and developed land, pine and other exotic plantations, reservoirs.

* Re-evaluated at time of delineation.

3.1.2 Establishing the threshold

For the purposes of the Lower North-East comprehensive regional assessment , the threshold for indicative national estate wilderness was considered equivalent to JANIS Wilderness (JANIS 1997, 15). That is, areas with a minimum “High Wilderness Quality” rating of 12 and above, and a minimum size of 8,000 ha were considered to meet the national estate threshold.



3.1.3 Results

The National Wilderness Inventory upgrade revealed that 13 areas in the Lower North-East region meet the JANIS criteria for defining high quality wilderness (minimum National Wilderness Inventory rating of 12 and a minimum size of 8000 hectares). Spatial distribution of indicative national estate wilderness is represented at Map 2. The combined extent of the thirteen delineated wilderness areas in the LNE region is 302074 hectares, as shown in Table 6.


TABLE 3: Land tenure of significant national estate wilderness values


Polygon number

Place

Total Area (ha)

Area in

Reserves (NP/NR only) (ha)

Proportion in Reserves

(NP/NR only) (%)

1

New England NP

32648

31658

97

2

Oxley wild Rivers NP

105791

67291

63.6

3

Werrikimbe

16821

15664

93.1

4

Barrington Tops

55531

52437

94.4

5

Wollemi NP (NE)

247

247

100

6

Wollemi NP (NW)

159

159

100

7

Wollemi NP (N)

2803

2635

94

8

Wollemi NP (South)

144854

142127

98.1

9

Putty

15908

11

0.1

10

Yengo

99367

96187

96.8

11

Parr SRA

22867

22867

100




Total

496996

431283

86.8

NB: figures are indicative only


3.2 Natural landscapes


Natural landscapes are large, relatively undisturbed areas with topographic and catchment integrity where natural processes continue largely unmodified by human intervention. Natural processes include:


  • energy flows;

  • nutrient cycling;

  • hydrological processes;

  • ecological processes such as succession; and

  • evolutionary processes such as speciation and extinction.

At a national level, ‘natural landscapes’ are considered rare, and in those Regional Forest Agreement regions where they are found they have generally been assessed under national estate criterion B.1—’importance for rare, endangered or uncommon flora, fauna, communities, ecosystems, natural landscapes or phenomena, or as a wilderness’.



3.2.1 Method

The following measures were used to identify areas of potential natural landscape value:




  • naturalness (or level of disturbance indicated by the biophysical naturalness indicator);

  • size and;

  • integrity in the landscape.

The assessment of natural landscapes was largely based on the biophysical naturalness indicator of the National Wilderness Inventory (method described in section 2.2.1)



3.2.2 Establishing the threshold

Areas of high biophysical naturalness (BN equals 4 or 5) and with an area of 1,000 ha or greater were identified. Areas adjacent to the coast with high biophysical naturalness were identified if greater than 250 ha. The set threshold was chosen to be consistent with the process carried out in the other CRA regions. Older biophysical naturalness layers for areas adjacent to but outside the region were used to allow potential areas on the boundary of the region to be assessed within context. In order to rationalise the identification of areas, identified areas could contain fragmented but not significant areas of disturbance. Boundaries were permitted to include areas of disturbed forest, but not cleared land or substantially modified landscapes such as plantations.



3.2.3 Results

A large number of natural landscapes were identified in lower north-eastern NSW. Natural landscapes follow the general line of the escarpment from the edge of the Dorrigo plateau south-west through New England National Park and Styx River State Forest to Oxley Wild Rivers National Park and Doyles River State Forest. Additional large areas occur on Barrington Tops, Yengo and Wollemi National Parks. Along the coastal plain, significant landscapes were identified in the Myall Lakes area, Crowdy Bay National Park, Limeburners Creek National Park, and Yessabah and Ingalba State Forests. The areas delineated are above the threshold for nomination on the Register of the National Estate and use the best available data from the comprehensive regional assessment for lower north-eastern NSW. There is a strong correlation with places already listed on the Register of the National Estate. These areas cover 1,690,874 ha. Delineated areas of natural landscapes are shown at Map 3.


Over 50% of the total natural landscape area identified as having indicative national estate significance occurs in existing reserve, including national park or nature reserve. 21% of the total area is in state forest (Table 4).
TABLE 4: Land Tenure of significant national estate natural landscape values


Tenure

Approximate Area (ha)

Proportion of Total (%)

National Park, Nature Reserve or PMP 1.3*

837,875

50%

Private Land

Not Available

Not Available

State Forest

351,516

21%

Leasehold Crown Land

Not Available

Not Available

Other Crown Land

Not Available

Not Available

*PMP 1.3 is the State Forests of NSW Preferred Management Priority Classification for areas reserved as Flora Reserves and Forest Preserves (Forestry Commission of NSW 1993)


3.3 Undisturbed catchments


‘Undisturbed catchments’ are catchments where natural hydrological processes remain essentially unmodified and unimpeded.

3.3.1 Method

The identification of undisturbed catchments was based on an analysis of river flow impediments and the naturalness of the area within the catchment. The assessment is derived from the River Disturbance Index Database (Stein et al 1998) held by the Wilderness and Wild Rivers Group, Environment Australia. The River Disturbance Index is a measure of river/stream quality across sub-catchment areas based on two indicators: Naturalness of Flow Regime Index; and Sub-Catchment Naturalness Index.


Delineation of catchments

Sub-catchments were identified from the wild rivers database, compiled for the wild rivers assessment that formed part of the lower north east comprehensive regional assessment. These sub-catchments were used as the basis of the national estate analysis. The database delineates a separate modelled sub-catchment for each stream segment, as defined on the AUSLIG 1:250,000 scale hydrography theme database.


Catchment Naturalness

The River Disturbance Index Database was constructed by establishing a grid across a primary database and calculating scores for sub-catchment condition (Sub-Catchment Naturalness Index) and flow regime indicators (Naturalness of Flow Regime Index). The scores for Sub-Catchment Naturalness Index were combined and adjusted for sub-catchment area to produce a Catchment Naturalness Index. The final River Disturbance Index values combine the Naturalness of Flow Regime Index and the Catchment Naturalness Index.


The primary database is derived from geographical data derived from topographical map series and the National Wilderness Inventory primary database. The National Wilderness Inventory sources provide settlement and infrastructure features, the extent of non-natural land cover and an index of biophysical naturalness (Lesslie and Maslen 1995). Topographical map series provides watercourse data, built-up areas, infrastructure, reservoirs and canals.
The River Disturbance Index was created using guidelines established by an expert panel of government and non-government officials and stakeholders. Panel participants helped develop decision rules on quantifying disturbance and measuring catchment and river naturalness. From these discussions, the River Disturbance Index rates sub-catchment areas on a scale from undisturbed (0) to disturbed (1).

3.3.2 Establishing the threshold

Selection of a threshold to capture intact and undisturbed catchments was made on the basis that highly undisturbed catchments occur in the River Disturbance Index range less than or equal to 0.01.


Using geographic information system, the data was filtered to capture all sub-catchments less than or equal to 0.01. Those places falling within these parameters were deemed to have indicative national estate value for undisturbed catchments.
Areas of high biophysical naturalness (BN equals 4 or 5) and with an area of 1,000 ha or greater were identified. The set threshold was chosen to be consistent with the process carried out in the other CRA regions.
Undisturbed catchments that were under 1000 ha along the boundary of the RFA region were investigated to see whether such units were part of a larger undisturbed catchment that extended beyond the region. Older biophysical naturalness layers for areas adjacent to but outside the region were used for this investigation. A lower area threshold of 250 ha was permitted for areas adjacent to the coast. No small boundary units matching either of the instances just specified were identified in lower north-eastern NSW.
In order to rationalise the identification of undisturbed catchment areas, boundaries were permitted to include areas of disturbed forest, but not cleared land or substantially modified landscapes such as plantations.

3.3.3 Results

After applying the size threshold of 1,000 ha, significant indicative undisturbed catchments were identified with an area of approximately 1,138,869 ha (Table 5, Map 4). The areas identified are above threshold level to warrant national estate listing and have been delineated using best available data from the lower north-eastern CRA.


Areas delineated were mainly associated with the great escarpment from the edge of the Dorrigo plateau south-west through New England National Park and Styx River State Forest to Oxley Wild Rivers National Park and Doyles River State Forest. Additional large areas occur on Barrington Tops, Yengo and Wollemi National Parks. These areas have - at least in part - been previously listed on the Register of the National Estate.
Table 5: indicative undisturbed catchment areas


Place

Area (ha)

Place

Area (ha)




Oxley Wild Rivers & Werrikimbe NP

258919

Heaton SF

1994




Wollemi NP & W Putty SF

230106

Mooral Creek S of Marsh SF

1856




Yengo & Dharug NP

224363

Area Between W Putty SF & Yengo NP

1794




Barrington Tops NP & SF

98531

Masseys Creek SF

1738




New England NP, Nulla-Five Day & Oakes SF's

98019

Gangat & Bucklebore Mountain area

1731




PT Heaton& Olney SF

13713

Nth West Oxley Rivers NP

1694




Camels Hunt NR & Surrounds

12650

Kalateenee SF

1688




E Putty SF

11450

NW Bulga SF

1675




Woko NP

10200

NE Wollemi NP

1594




Giro SF

10075

S Crowdy Bay NP

1481




Riamukka

9063

NW Yengo NP

1475




Dorrigo NP

8994

SW Doyles River SF

1444




Manobalai NR

8606

Crown Land NW of Mernot SF

1444




Enfield SF

8388

Briggsvale

1325




Cathedral Rock NP & Yooroonah SF

7306

Area S of SW Oxley Wild Rivers NP

1325




SE Tuggolo SF

6956

Crown Land Kurri Kurri

1313




Styx River SF

6675

Ben Halls Gap NP

1281










Nundle SF

1275




Watagan & Corrabare SF

6169

W Pappinbarra SF

1181




Chichester SF

6125

SW Tuggolo SF

1144




NW Wollemi NP

5813

W Cairncross SF

1119




Knorrit SF

5688

Crown Land between Cochrane & Carrai SF

1100




SE Bulga SF

4963

Regatta, Wallis & Cockatoo Islands

1031




Mistake SF

4631

Doyles River SF

1006




Yessabah SF

4581

Serpentine NR

956




NW Wollemi NP

4569

Tuckers Knob SF

731




W Wollemi NP

3900

W Wollemi NP

588




Ingalba

3894

W Wollemi NP

319




Coneac & N Bowman SF

3888

W Wollemi NP

288




N Tuggolo SF

3769

W Wollemi NP

256




Trevor & Fosterton SF

3481

NW Wollemi NP

181




N Wollemi NP

3425

NW Wollemi NP

144




Cockspur SF

2644

NW Wollemi NP

25




SW Oxley Wild Rivers NP

2619

W Yengo NP

6




Dingo SF

2288

SW Yengo NP

6




Camden Haven SF & N Crowdy Bay NP

2181

W Wollemi NP

6




Area N of Cockspur SF

2019







TABLE 6: Land Tenure of indicative national estate undisturbed



catchment values


Tenure

Approximate Area (ha)

Proportion of Total (%)

National Park, PMP 1.3 or Nature Reserve

691,042

61%

State Forest

228,794

20%

Private Land

Not Available

Not Available

Leasehold Crown Land

Not Available

Not Available

Other Crown Land

Not Available

Not Available

*PMP 1.3 is the State Forests of NSW Preferred Management Priority Classification for areas reserved as Flora Reserves and Forest Preserves (Forestry Commission of NSW 1993)


3.4 Old-growth forest


The importance of old-growth forests was assessed in terms of the maintenance of existing natural processes (Sub Criterion A.2)
The comprehensive regional assessment work is guided by the JANIS criteria which defines old-growth forest as ‘ecologically mature forest where the effects of disturbances are now negligible’ (JANIS 1997, p. 13). Old-growth forests in Australia are considered rare at the national level. Old-growth forests have intrinsic value as the oldest growth-stage of a given vegetation class or community as well as those characteristics, associated with those oldest age class-dominated forests. For example, senescent trees are important for providing nesting and roosting sites for large forest owls and arboreal mammals.
In the lower north-east comprehensive regional assessment region, comparatively large tracts of old-growth forest are to be found along the escarpment north of Doyles River State Forest and in the Wollemi and Yengo national parks. Most stands of old growth occur in complex mosaics of mature and younger forest on accessible parts of the adjacent ranges. Old growth is particularly uncommon on the coastal plain. The most extensive areas remaining on the coastal plain and ranges include large discrete areas in Ingalba, Kalateenee State Forests and Barrington Tops National Park and smaller areas in Myall River State Forest and Myall Lakes National Parks.
The assessment of old-growth forest of indicative national estate value is considered under sub-criterion B.1 (Natural rarity) and sub-criterion A.2 (Continuing processes). Sub-criterion B.1 focuses on examples of old-growth forest for particular forest communities that are rare or uncommon at a regional level, while sub-criterion A2 recognises the importance of old-growth forests for the maintenance of existing natural processes (Appendix A).

3.4.1 Method

The old-growth forest identified according to the JANIS criteria was used as the primary data-set for identification of indicative national estate old-growth forest values in lower north-east. Detail on the processes used to delineate old-growth forest can be obtained from the CRA Old-growth forest Report. (NPWS 1998)


Areas of indicative national estate old-growth forest significant for ecological processes (under criteria A.2) are considered to be those that have high integrity and natural context (as identified by the National Wilderness Inventory biophysical naturalness index) and above a minimum size threshold to ensure the viability and quality of the forest stand.

3.4.2 Establishing the threshold

The old-growth forest layer was over laid with the natural landscapes and undisturbed catchments layers. It was assumed that within these areas, all old-growth forest regardless of size possess a high level of integrity. Outside areas of natural landscapes and undisturbed catchments, a minimum viable forest patch size threshold of 100 ha was applied.



3.4.3 Results

The process outlined above delineated 838,219 ha of old-growth forest in the lower north-eastern CRA region as above threshold. Approximately 71% is in existing reserves and approximately 16% is in State Forest (Table 7). Areas of indicative national estate old-growth forest, identified under sub criterion A.2 are illustrated at Map 5.


TABLE 7: Land Tenure of indicative national estate Old-growth forest


Tenure

Approximate Area (ha)

Proportion of Total (%)

National Park, PMP 1.3 or Nature Reserve

594,861

71%

State Forest

133,479

16%

Private Land

Not Available

Not Available

Leasehold Crown Land

Not Available

Not Available

Other Crown Land

Not Available

Not Available

*PMP 1.3 is the State Forests of NSW Preferred Management Priority Classification for areas reserved as Flora Reserves and Forest Preserves (Forestry Commission of NSW 1993)



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