Coastal Cypress Pine Forest in the NSW North Coast Bioregion - endangered ecological community listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list Coastal Cypress Pine Forest in the NSW North Coast Bioregion as an ENDANGERED ECOLOGICAL COMMUNITY in Part 3 of Schedule 1 of the Act. Listing of endangered ecological communities is provided for by Part 2 of the Act.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. Coastal Cypress Pine Forest in the NSW North Coast Bioregion is the name given to the ecological community dominated by Coastal Cypress Pine, Callitris columellaris, found typically on coastal sand plains, north from the Angourie area on the far north coast of NSW. The community is characterised by the species listed in paragraph 2, and typically has a closed to open canopy of  C. columellaris, which may be mixed with eucalypts, wattles, banksias and/or rainforest trees, and an open to sparse understorey of shrubs, sedges and herbs. Structural forms of the community include woodland, open forest and closed forest, although the tree stratum may be very sparse, absent, or comprised only of dead trees in stands affected by partial clearing, tree senescence or fire.

2. Coastal Cypress Pine Forest is characterised by the following assemblage of species:

3. The total species list of the community is considerably larger than that given above, with many species present in only one or two sites or in low abundance. The species composition of a site will be influenced by the size of the site, recent rainfall or drought condition and by its disturbance (including fire) history. The number of species, and the above ground relative abundance of species will change with time since fire, and may also change in response to changes in fire regime (including changes in fire frequency). At any one time, above ground individuals of some species may be absent, but the species may be represented below ground in the soil seed banks or as dormant structures such as bulbs, corms, rhizomes, rootstocks or lignotubers. The list of species given above is of vascular plant species; the community also includes micro-organisms, fungi, cryptogamic plants and a diverse fauna, both vertebrate and invertebrate. These components of the community are poorly documented.

4. Coastal Cypress Pine Forest is dominated by a dense to open canopy of Callitris columellaris (Coastal Cypress Pine), sometimes with  Coyrmbia intermedia (Pink Bloodwood),  Eucalyptus pilularis (Blackbutt),  E. signata (Scribbly Gum),  Acacia disparrima subsp.  disparrima (Salwood),  Allocasuarina littoralis (Black She-oak),  Banksia integrifolia subsp.  integrifolia (Coast Banksia) or  B. serrata (Old Man Banksia). The typically sparse layer of shrubs may include,  Acacia ulicifolia (Prickly Moses),  Leucopogon ericoides (Pink Beard-heath),  L. leptospermoides,  Monotoca  elliptica (Tree broom-heath) and juveniles of any of the canopy species. The typically sparse groundcover comprises scattered grasses, including  Aristida vagans (Three-awn Speargrass),  Eragrostis brownii (Brown’s Lovegrass),  Imperata cylindrica var.  major (Blady Grass) and  Paspalidium distans, graminoids such as  Baloskion  tetraphyllum subsp.  meiostachyum (Plume Rush) and  Lomandra longifolia (Spiny-headed Mat-rush) and forbs including  Dianella caerulea (Blue Flax Lily) and  Pomax umbellata or it may also contain a rich orchid flora (Moye  in  litt. 2008). The community may have a distinctive litter layer with patches of compressed  Callitris branchlets, which have a characteristic chemical composition that is high in terpenes, such as limonene and pinene (Ogunwande  et al. 2005). Undisturbed stands of the community may have a woodland or forest structure, with  C. columellaris dominating the canopy, although larger trees, such as eucalypts may be emergent. Stands of the community that have been partially cleared in the past may be reduced to scattered trees and a few characteristic ground cover species, possibly with other native species represented in a soil seed bank. Fires may also influence the structure of the community, as the dominant tree species,  C. columellaris, is generally killed when burnt. Post-fire regeneration of the community may therefore have the structure of shrubland or heathland for many years.

5. A number of threatened flora species have been recorded in Coastal Cypress Pine Forest or associated ecotones. These include Acronychia littoralis (Scented Acronychia),  Archidendron hendersonii (White Lace Flower),  Geodorum densiflorum (Pink Nodding Orchid, Shepherds Crook Orchid) and  Drynaria rigidula (Basket fern).

6. Coastal Cypress Pine Forest typically occurs on the inland side of the coastal sandplain on low rises that represent eroded Pleistocene backbarrier dunes (Morand 1996). A few examples of the community are located on coastal bedrock hills mantled with wind-blown sand or more rarely without a sandy mantle (e.g. Landmark 1999). The community has also been recorded from Holocene sand dunes (Griffith 1999). The sandy soils are generally deep, freely draining podsols, loam or clay soils associated with basalt or, less commonly, fine-grained sedimentary rocks and similar substrates. Currently known occurrences of the community are generally within 35km of the coast and below 100m elevation. Mean annual rainfall varies from approximately 1000 mm up to 1800 mm across the distribution of the community.

7. Coastal Cypress Pine Forest is apparently restricted to the NSW North Coast bioregion. The dominant species, C. columellaris, extends into south-east Queensland as far north as Hervey Bay. Biantoff and Elsol (1989) record  C. columellaris in forest on the Sunshine Coast in south-east Queensland, although it is uncertain whether this represents the same community or other communities in which  C. columellaris is sub-dominant. However, any occurrence of the community in south-east Queensland is likely to be highly restricted. In NSW, Coastal Cypress Pine Forest is currently known from the local government areas of Tweed, Byron, Ballina, Richmond Valley and Clarence Valley, but may occur elsewhere within the bioregion.

8. Coastal Cypress Pine Forest includes ‘Coast Cypress Pine’ (Forest Ecosystem 22) of NPWS (1999) and DEC (2004), ‘Callitris columellaris tall open to closed forest’ (F4) of Pressey and Griffith (1992), the ‘Cypress Pine’ unit of Landmark (1999), ‘Cypress Pine Open Forest to Woodland’ (313) of Kingston  et al. (2004), Coast Cypress Pine on Dunes and Ridges’ (Community 33) of Sherringham  et al. (unpubl. data) and Coastal Cypress Pine assemblages described by Benwell (1995, 1998). Coastal Cypress Pine Forest belongs to the Coastal Dune Dry Sclerophyll Forests vegetation class of Keith (2004).

9. Based on detailed field inspections, the total distribution of Coastal Cypress Pine Forest covers approximately 150 ha (A. Benwell, unpubl. data), and is certainly less than 200 ha. Coastal Cypress Pine Forest is currently known from 15-20 localities, most of which are patches no larger than 10 ha. Stands of the community have been mapped in Bundjalung, Yuraygir and Broadwater National Parks (Griffith 1983, 1984, 1985) and Billinudgel Nature Reserve (Benwell 1998), accounting for about half of the total known occurrence. The remaining stands occur primarily on private land or road easements. All known occurrences of the community are within a total extent of occurrence of 2500 –3000 km². These estimates indicate that the community has a highly restricted distribution.

10. Since European settlement, and relative to the longevity of its dominant trees, which live for more than a hundred years, Coastal Cypress Pine Forest has undergone a large reduction in geographic distribution. This reduction has occurred as a result of vegetation clearing for sand mining, agriculture and coastal development. Estimates based on field observations of old remnant trees in cleared land around the remaining stands of the Coastal Cypress Pine Forest suggest that the area occupied by the community may have declined by more than 77% (A. Benwell, unpubl. data). The actual reduction in geographic distribution is likely to be larger than this estimate suggests because stands which may have been totally destroyed could not be included in the calculation. Small-scale clearing continues to threaten the community, primarily as a result of coastal development and associated upgrading of roads. For example, within the past two decades, fragmentation of the community has increased as a result of clearing for tea tree plantations, caravan parks, road construction and associated quarrying (DECC in litt., A. Benwell, pers. comm. August 2006), indicating a continuing decline in the geographic distribution of the community. The remaining area of the community is severely fragmented. The integrity and survival of small, isolated stands of the community is impaired by the small population size of its component species, enhanced risks from environmental stochasticity, disruption to pollination and dispersal of fruits or seeds, and likely reductions in the genetic diversity of isolated populations (Young  et al. 1996, Young and Clarke 2000). ‘Clearing of native vegetation’ is listed as a Key Threatening Process under the  Threatened Species Conservation Act 1995.

11. Other threats to Coastal Cypress Pine Forest include habitat degradation and weed invasion. Maintenance of service easements and fence construction encroaches on the edges of some stands, while trampling and rubbish dumping occurs where the community is close to towns and recreational sites. Such disturbances accelerate the invasion of weeds, which may form a dense understorey or ground layer, displacing native understorey species and inhibiting recruitment of canopy species. Principal weed species include Asparagus  aethiopicus,  Bryophyllum delagoense,  Chloris gayana, Lantana camara, Ochna serrulata and  Schefflera actinophylla. Other weed species recorded in the community include  Panicum maximum, Rhaphiolepis indica, Solanum nigrum and  S. seaforthianum. The invasion and establishment of exotic species in Coastal Cypress Pine Forest, results in a large reduction in the ecological function of the community. ‘Invasion of native plant communities by exotic perennial grasses’ and ‘Invasion, establishment and spread of  Lantana ( Lantana camara L.  sens. lat)’ are listed as Key Threatening Processes under the  Threatened Species Conservation Act 1995.

12. Inappropriate fire regimes also pose a threat to Coastal Cypress Pine Forest. Undisturbed stands of the community typically have a sparse understorey and apparently do not accumulate large quantities of uncompacted litter. These attributes do not favour propagation of fires under common weather conditions. However, the dominant species, C. columellaris, may be killed by crown fires or heavy scorching of the lower trunk. Such effects have been observed in localised patches (A. Benwell, pers. comm.), as incursion of fire may be facilitated by more flammable vegetation that surrounds the small patches of the community. A recent crown fire in Bundjalung National Park killed existing seedlings, saplings and mature trees of  C.columellaris and apparently resulted in little post-fire recruitment (S. J. Griffith, pers. comm.). Regeneration of the species appears to rely on seed that is released regularly from non-persistent cones, mainly in the summer months. Seedling recruitment is mainly seen in gaps created by small-scale disturbance (A. Benwell, pers. comm.). Given these characteristics and observations, high-frequency fires are likely to be detrimental to the persistence of the community, although infrequent fires may be necessary to create the gaps apparently required for seedling recruitment to replace senescent trees. Frequent fires are also likely to accelerate the invasion of weeds, since these species are efficient colonisers of open space where there are sources of propagules nearby. Weed invasion is likely to alter the fuel characteristics, making the community more flammable. Increasing human population pressures, such as those occurring on the NSW north coast, typically result in an increase in fire ignitions in bushland that is accessible to urban areas. ‘High frequency fire resulting in disruption of life cycle processes in plants and animals and loss of vegetation structure and composition’ is listed as a Key Threatening Process under the  Threatened Species Conservation Act 1995.

13. Coastal Cypress Pine Forest in the NSW North Coast Bioregion is not eligible to be listed as a critically endangered ecological community.

14. Coastal Cypress Pine Forest in the NSW North Coast Bioregion is eligible to be listed as an Endangered Ecological Community as, in the opinion of the Scientific Committee, it is facing a very high risk of extinction in New South Wales in the near future, as determined in accordance with the following criteria as prescribed by the Threatened Species Conservation Regulation 2002:

Clause 25

The ecological community has undergone, is observed, estimated, inferred or reasonably suspected to have undergone, or is likely to undergo within a time span appropriate to the life cycle and habitat characteristics of its component species:

(b) a large reduction in geographic distribution.

Clause 26

The ecological community’s geographic distribution is estimated or inferred to be:

(b) highly restricted,

and the nature of its distribution makes it likely that the action of a threatening process could cause it to decline or degrade in extent or ecological function over a time span appropriate to the life cycle and habitat characteristics of the ecological community’s component species.

Clause 27

The ecological community has undergone, is observed, estimated, inferred or reasonably suspected to have undergone, or is likely to undergo within a time span appropriate to the life cycle and habitat characteristics of its component species:

(b) a large reduction in ecological function,

as indicated by any of the following:

(d) change in community structure

(g) invasion and establishment of exotic species

(h) degradation of habitat

(i) fragmentation of habitat

Professor Lesley Hughes
Chairperson
Scientific Committee

Proposed Gazettal date: 31/10/08

Exhibition period: 31/10/08 – 26/12/08

References

Benwell AS (1995) Vegetation of the Wardell heathlands. Report to NSW National Parks and Wildlife Service, Coffs Harbour.

Benwell AS (1998) Vegetation map of the Billinudgel Nature Reserve. Report to NSW National Parks and Wildlife Service, Coffs Harbour.

Biantoff GN, Elsol JA (1989) Vegetation of the Sunshine Coast – description and management. Queensland Botany Bulletin No. 7. Queensland Department of Primary Industries, Brisbane.

DEC (2004) Natural Resource Management Field Assessment Guidelines. Field Key to Forest Ecosystems. NSW Department of Environment and Conservation, Coffs Harbour.

Griffith SJ (1983) A survey of the vegetation of Bundjalung National Park. Report to NSW National Parks and Wildlife Service, Grafton.

Griffith SJ (1984) A survey of the vegetation of Yuraygir National Park. Report to NSW National Parks and Wildlife Service, Grafton.

Griffith SJ (1985) A survey of the vegetation of Broadwater National Park. Report to NSW National Parks and Wildlife Service, Grafton.

Griffith SJ (1999) Vegetation of Broadwater, Bundjalung and Yuraygir National Parks, and Iluka Nature Reserve. Unpublished report to NPWS.

Keith DA (2004) ‘Ocean shores to desert dunes: the native vegetation of New South Wales and the ACT.’ NSW Department of Environment and Conservation, Sydney.

Kingston MB, Turnbull JW, Hall PW (2004) Tweed vegetation management strategy 2004. Report to Tweed Shire Council, Tweed Heads. Ecograph.

Landmark (1999) Byron flora and fauna study. Report to Byron Shire Council, Byron Bay. Landmark Ecological Services.

Morand DT (1996) Soil landscapes of the Murwillumbah-Tweed Heads 1:100000 sheet (Department of Land and Water Conservation: Sydney).

NPWS (1999) Forest ecosystem classification and mapping for the upper and lower north east Comprehensive Regional Assessment. NSW National Parks and Wildlife Service, Coffs Harbour.

Ogunwande IA, Olawore NO, Adeleke KA, Konig WA (2005) Analysis of the volatile compounds of Calliltris  columellaris F. Muell. Needles from two different regions of Nigeria.  Journal of Essential Oil Research17 , 44-46.

Pressey RL, Griffith SJ (1992) Vegetation of the coastal lowlands of Tweed shire, northern New South Wales, species and conservation. Proceedings of the Linnean Society of NSW113 : 203-243.

Young A, Boyle T, Brown A (1996) The population genetic consequences of habitat fragmentation for plants. Trend in Ecology and Evolution11 , 413-418.

Young A, Clarke G (2000) Genetics, demography and the viability of fragmented populations. (Cambridge University Press: Cambridge)