It is intended that this Plan be implemented over a ten-year period



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2.4Climate


North-east NSW and south-east Queensland are located in a transition zone between a belt of steady trade winds to the north and an anticyclonic belt to the south. The oscillation of these two features over the region results in a climate that is largely subtropical. In summer, easterly to south-easterly winds predominate, while in winter, dry westerly to south-westerly winds predominate. These result in a distinct summer–autumn rainfall maximum, relatively dry springs, and fine sunny days with cool nights in winter (Natural Resource Audit Council 1995; DECCW website).

Within the Border Ranges region rainfall generally reduces as distance from the coast increases (see Figure 5). This trend is modified by topography, however, with higher orographic rainfall occurring in the mountainous areas and lower rainfall in the low-lying valleys and floodplains. Many of the valleys in the lee of the higher elevation ranges and prominent mountains experience rain-shadow effects and have markedly lower precipitation than the adjacent ranges to the east (Adam 1987). The highest rainfall areas are the Springbrook and Lamington Plateaus and the Tweed and Nightcap Ranges, with annual falls over 3000 mm.

Climate change predictions for northern NSW and south-eastern Queensland indicate a shift to warmer minimum and maximum temperatures, more extreme fire event days, fewer but more intense extreme weather events, and rises in sea level.


  1. Topography

  2. Geology

  3. Annual rainfall

2.5Broad vegetation groups


Around 710 000 ha (49%) of the Border Ranges region supports some form of native vegetation. This includes estuarine mangroves and saltmarshes, wetlands, heathlands, swamp sclerophyll forests, grassy sclerophyll woodlands, dry and wet sclerophyll forests, rainforests and highly restricted communities such as montane heathlands.

The classification systems used for vegetation mapping are not consistent between NSW and Queensland. To allow cross-border mapping, spatial modelling and planning for this Plan, various classifications have been integrated to derive a single, consistent classification. Over 100 distinct vegetation communities or ecosystems were identified in this process, and these were grouped into 17 vegetation formations and then 6 broad vegetation groups as detailed in Table 3. Figure 6 shows the distribution of broad vegetation groups in the Border Ranges region.



  1. Vegetation groups and formations

Broad vegetation group

Vegetation formation

No. of ecosystems

Rainforest

Cool temperate rainforest

2

Dry rainforest

3

Littoral rainforest

3

Semi-evergreen vine thicket

5

Subtropical rainforest

8

Warm temperate rainforest

1

Wet sclerophyll forest

Wet sclerophyll forest

18

Dry sclerophyll forest

Dry sclerophyll shrub forest

10

Dry sclerophyll shrub/grass forest

37

Other native

Swamp sclerophyll forest

4

Estuarine and saline wetland

2

Freshwater wetland

2

Grassland

1

Heathland

10

Introduced

Introduced

1

Plantation

2

Camphor Laurel

Camphor Laurel

1




  1. Broad vegetation groups

2.6Rainforest and related vegetation


This Plan seeks to address threats to ‘rainforest and related vegetation’ which encompasses the following:

  • rainforest; that is, subtropical, warm temperate, cool temperate, dry and littoral rainforest and semi-evergreen vine thickets

  • wet sclerophyll forest

  • vegetation communities of limited extent that are typically surrounded by rainforest; that is, cliffs, rocky outcrops and montane heath

  • riparian vegetation surrounded by or adjacent to rainforest.

This definition mirrors the Australian Government’s description of the Border Ranges North and South (Queensland and NSW) Biodiversity Hotspot (Department of the Environment and Water Resources 2007). Riparian vegetation is deemed to be a ‘transition forest’, and these areas are included in this Plan where they occur within or adjoining rainforest. As such, tables and figures do not distinguish riparian vegetation.

Appendix 5 (on the enclosed CD) contains a detailed discussion on the classification systems used for mapping and delineating rainforest and related vegetation for the purposes of this Plan. Figure 7 shows the distribution of rainforest and related vegetation in the Planning Area.

Rainforest and related vegetation covers approximately 291 600 ha, or 20%, of the Border Ranges region. As Table 4 shows, the majority of this is comprised of subtropical rainforest (46%) and wet sclerophyll forest (36%). The subtropical rainforests of the Border Ranges region represent the most significant Australian refugia for early Tertiary subtropical and dry rainforests (Department of the Arts, Sport, Environment and Territories 1992). It is also significant that over 11% of the rainforest and related vegetation is dry rainforest. The other vegetation types make up a much smaller component of the Planning Area.


  1. Rainforest and related vegetation

Component vegetation types

Area

(ha)

Proportion of all rainforest and related vegetation (%)

Subtropical rainforest

135 579

46.5

Wet sclerophyll forest

104 779

35.9

Dry rainforest

32 530

11.2

Camphor Laurel *

11 269

3.9

Heath & rocky areas

2 946

1.0

Cool temperate rainforest

1 797

0.6

Semi-evergreen vine thicket

1 680

0.6

Warm temperate rainforest

606

0.2

Littoral rainforest

417

0.1

TOTAL

291 600

100

* see discussion below on Camphor Laurel

Table 5 provides information on where rainforest and related vegetation occurs in relation to the various land tenures in the Planning Area. Over half of rainforest and related vegetation occurs on national parks and other conservation reserves, while approximately 37% is located on private land. This highlights the importance of managing rainforest across both public and private tenure.



  1. Proportion of rainforest and related vegetation occurring on different land tenures

Tenure

Rainforest and related vegetation

Area (ha)

Proportion of total (%)

Conservation reserves*

153 101

52.5

Private property freehold

107 745

36.9

State forests

22 506

7.7

Crown lands

3 852

1.3

Commonwealth lands

1 872

0.6

Private property conservation

1 579

0.5

Gold Coast Council land

944

0.3

* includes 85 655 ha of rainforest and related vegetation in Gondwanan Rainforests of Australia WHA

The rainforest and related vegetation of the Border Ranges region forms an important component of the Gondwana Rainforests of Australia WHA, formerly Central Eastern Rainforest Reserves of Australia WHA. They support four rainforest types: cool temperate rainforest, warm temperate rainforest, subtropical rainforest, and dry rainforest. The Gondwana Rainforests of Australia WHA is recognised as containing important and significant habitats where threatened species of plants and animals of outstanding universal value still survive (Commonwealth of Australia 2007). The Gondwana Rainforests are also included on the National Heritage List because they possess uncommon, rare or endangered aspects of Australia’s natural or cultural history (Commonwealth of Australia 2007). Within the Border Ranges region, the Gondwana Rainforest reserves attract a high number of visitors per year, and as such are very significant to the socio-economics of the area.

Much of the following information has been summarised from Adam (1987), Floyd (1990) and QEPA (2007), and these sources should be referred to for more detailed information. The general pattern of rainforest distribution is related to temperature, rainfall, soil type and fire history. Localised climate variations and fire behaviour are affected by topography, which in turn affect patterns of rainforest distribution.

For some rainforest types such as cool temperate rainforest, climate is the strongest influence on distribution, while soil fertility has a relatively low influence. Warm temperate rainforest generally occurs on lower fertility soils than subtropical rainforests. It also occurs at higher altitudes, possibly reflecting a requirement for higher rainfall or an adaptation to cooler temperatures. Where high soil fertility occurs at higher altitudes, subtropical rainforest may occur at similar altitudes to warm temperate rainforest. Where there is a strong seasonality to rainfall and lower overall rainfall, dry rainforest is more likely to occur than subtropical rainforest. Dry rainforest is more likely to persist in areas that have a higher degree of fire protection than exposed sites. Littoral rainforest occurs at coastal sites protected from fire but subject to persistent salt spray and strong winds. Semi-evergreen vine thickets occupy the driest sites, typically on higher fertility soils.



  1. Rainforest and related vegetation

Subtropical rainforest covers approximately 135 580 ha, or 46%, of the Planning Area. This rainforest community once covered extensive areas of the fertile lowlands and floodplains in the Border Ranges region. In the east of the region, it is generally restricted to soils of basaltic origin, with large stands remaining at mid to high altitudes in Wollumbin, Border Ranges, Nightcap and Lamington National Parks, and Limpinwood and Numinbah Nature Reserves. There are also stands on metasediments and basalt in sheltered valleys along many of the coastal ranges such as the Burringbar, Condong, Beechmont and Darlington Ranges.

Isolated fragments of subtropical rainforest that represent the remnants of the Big Scrub occur near Lismore on both private land and in a number of conservation reserves such as Boatharbour, Victoria Park, Moore Park and Davis Scrub Nature Reserves. Further north, Stotts Island Nature Reserve supports the largest stand of lowland subtropical rainforest in the Tweed Valley and there are other lowland remnants at Nichols and Bahrs Scrubs in Queensland. Further west, along the McPherson Range, there are stands of subtropical rainforest at the base of Mt Glennie, Mt Chinghee, Mt Nothofagus and Mt Lindesay, with the largest unlogged stand occurring on Levers Plateau. There are also large stands in the Richmond Range at Dome Mountain and Murrays Scrub near Toonumbar, as well as further south at Bungdoozle and Cambridge Plateau. In the upper Clarence, stands exist along the Tooloom Range culminating in a large stand at the southern end on the elevated plateau of Yabbra Scrub, and also along the Koreelah Range including the extensive Tooloom Scrub area. Stands also exist along the Main Range in Queensland, with the most extensive being in the Mt Roberts and Mt Superbus area just north of the NSW–Queensland border and further north on the Mistake Plateau to the north of Cunninghams Gap.

Wet sclerophyll forest occurs extensively throughout the Planning Area covering some 104 780 ha, or 36%. Major stands occur in the east along many of the coastal ranges such as the Nightcap, Burringbar, Condong, Beechmont, Darlington and Blackall Ranges, as well as the flanks of Mt Warning. Other major stands occur further west on the Richmond and Tooloom Ranges and around the flanks of Mt Lindesay and Mt Barney. Additionally, wet sclerophyll forest occurs in other smaller stands along the Main, Koreelah, McPherson, Mackellar and Tweed Ranges, often interspersed as a mosaic amongst rainforest. Throughout the region, it often forms a transitionary community between the wetter rainforest of the higher ranges and the dry sclerophyll forests of the lower slopes.

Dry rainforest covers 32 530 ha, or 11%, of the Planning Area. Dry rainforest typically occupies fertile soils, particularly on drier northern and western slopes where there is a marked seasonality in rainfall figures. Extensive stands in the Planning Area occur on Levers Plateau and along the lower southern sections of the Richmond Range, with well developed stands at Mallanganee and near Mt Pikapene. Other occurrences include the drier slopes of the western Tweed Valley in Limpinwood Nature Reserve and Mebbin National Park. There are also numerous small isolated pockets along the floodplain and the foothills of the Richmond Valley in areas such as Ruthven and Ettrick. In the upper Clarence there are larger stands in Captains Creek Nature Reserve at the southern end of the Koreelah Range, and also on the lower slopes below Acacia Plateau near Old Koreelah. In Queensland, there are large stands of dry rainforest in the north and west of Lamington National Park, particularly Coomera Valley and Canungra Creek Valley. Numerous small stands also occur near Boonah, Beaudesert and Canungra.

Stands of the introduced Camphor Laurel Cinnamomum camphora are particularly prevalent in some parts of the Planning Area, covering around 11 270 ha, or 3.9%. In some areas where it dominates it may be regarded as a type of rainforest vegetation for management purposes in that it can provide important seasonal resources (such as food for rainforest frugivores), and appropriate microclimates that facilitate rainforest regrowth (Neilan 2004). However, in those parts of the Planning Area where it is not as prevalent and is still actively taking over native vegetation, it should be considered an invasive species and be prevented from establishing.

Camphor Laurel favours high rainfall areas on fertile soils – such as those derived from basalt – and floodplains. In south-east Queensland, Camphor Laurel is widespread in the Tallebudgera and Nerang valleys, especially along the waterways were it is replacing the native riparian vegetation. In NSW, Camphor Laurel is most prevalent in the coastal areas but also occurs further inland, particularly along streams. In the Tweed Valley it occurs in three main areas: from Cobaki to Duroby, from Uki to Burringbar, and around the Duranbah area. In the Brunswick Valley it is common in an area encompassing Billinudgel, Main Arm and Mullumbimby. In the Richmond Valley it is especially common in the Wilson River catchment north of a line from Wardell to Lismore, with heavy infestations around the Alstonville, Tintenbar and Bangalow areas (Scanlon & Camphor Laurel Task Force 2001).

Montane heath, rocky outcrops and cliffs typically occur as small narrow bands on the precipitous slopes of the Mt Warning and Focal Peak Calderas. These areas cover just one per cent of the Planning Area. Major occurrences include the upper slopes of Mt Warning on trachyte, the prominent rhyolitic escarpments of the Tweed, McPherson and Nightcap Ranges, as well as the cliffs surrounding the Lamington Plateau. Further west, montane heath, rocky outcrops and cliffs occur on the trachyte plugs associated with Mt Lindesay and Mt Barney as well as around Urbenville and on the cliffs along the Koreelah and Main Ranges. An extensive area of montane heath and rocky outcrops also occurs in Bald Rock State Forest west of Woodenbong.

Cool temperate rainforest reaches its northern limit in the Planning Area and covers less than one per cent, or 1780 ha. Most occurrences are above 1000 m elevation and are typically subject to persistent rain, clouds and mists. The largest stand of cool temperate rainforest in the Planning Area is on the NSW–Queensland border in the Mt Nothofagus and Mt Ballow areas. In Queensland, stands dominated by Lilly Pilly Syzygium smithii occur at higher altitudes along the Main Range near Mt Roberts and Mt Superbus, Mt Huntley and Panorama Point, and north of Cunninghams Gap. There are also several stands in Lamington and Springbrook National Parks along the top of the McPherson Range escarpment and the higher headwaters of the north-flowing creeks. In NSW, all other stands are much further east of the Mt Nothofagus occurrence, on the tops of the Tweed Range escarpment and the higher headwaters of the western flowing creeks of the eastern Border Ranges. The most easterly stand is a small occurrence in Numinbah Nature Reserve.

Semi-evergreen vine thickets only occur in the far west and north-west of the Planning Area, covering an area of 1680 ha. They occupy small isolated patches in two main areas: north of Killarney in the headwaters of the Condamine River, and along Lower Black Duck Creek in the headwaters of Lockyer Creek.

Warm temperate rainforest, with the exception of a few high altitude outliers further north in Queensland, also reaches its northern limit in the Planning Area. It covers just 606 ha of the Planning Area. It is generally found on soils that are too infertile to support subtropical rainforest, as well as on high, windswept ridges where the thin basaltic soils and strong cold winds prevent the development of subtropical rainforest. The major occurrence of warm temperate rainforest is on the rhyolitic soils of the Nightcap Range with other small pockets in higher-altitude gullies of Lamington and Springbrook National Parks and along the eastern Border Ranges in exposed locations. There are also small stands at lower elevations at upper Currumbin, Tallebudgera and Mudgeeraba Creeks. Further west, warm temperate rainforest occurs on the high plateau of Mt Glennie and at Mt Nothofagus.

Littoral rainforest has been extensively cleared and is now restricted to coastal headlands and dunal systems in close proximity to the coast. There are just 417 ha of littoral rainforest in the Planning Area. The major occurrences are at Broken Head, Brunswick Heads, Wooyung and near Fingal Head.



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