Gondwana Rainforests of Australia

Incompatible land-use on adjoining properties, escaped fires, groundwater extraction, uncontrolled domestic animals, garden weeds, feral animals and pressure for residential and tourist development may pose a threat in some locations. Off-site activities such as clearing and erosion within upstream catchments may be a potential threat for the attributes of the Outstanding Universal Value in some sections of the World Heritage site (IUCN Consultation, 2017). The approval and construction of ecotourism infrastructure in some sections of the site have been subject to a thorough Environmental Impact Assessment process and approved by the federal and state government authorities (Queensland Department of Environment; Commonwealth Department of Agriculture, Water and Environment).

Climate change, resulting in increased average temperatures in all seasons, more hot days and warm spells with a substantial increase in the temperature reached on hot days, frequent and intense storms, and changes to the cloud base, mist availability, humidity or rainfall is emerging as one of the greatest challenges for the protection of Gondwana Rainforests World Heritage values (CSIRO, 2019). Climate change is also predicted to exacerbate other threatening processes such as invasive species and pathogens, as well as fluctuations in rainfall patterns and altered fire regimes. In the austral spring and summer of 2019-2020 extensive fires (51% surface area of the World Heritage site) was impacted in wild fires. The fires followed and were coincident with a prolonged drought (NSW DPIE, 2020; Dickman et al., 2020; DAWE, 2020). The Final Report of the NSW Bushfire Inquiry (DPC, 2020) stated that climate change clearly played a role in  the  extreme 2019/20 fire season.

Tourism development, increasing visitor numbers  and visitor infrastructure is identified as a threat  in some park management plans. There are high levels of visitation in several visitor precincts in a number of the reserves (IUCN Consultation, 2017). Visitation is managed to minimise impact while supporting the visitor experience and appreciation of values. Where management of human visitation is identified as an action required to protect a threatened species managed under the NSW Government’s Saving our Species program, responses of the target species to threat management are monitored. Queensland’s State of the Environment Report (2017) indicated that increasing visitor numbers, and associated supporting infrastructure, present a minor and localised threat, addressed within the relevant national park management plans and statements and considered the threat are low (SoE, 2017).
 

Several introduced pathogens threaten the values of the World Heritage site including Phytophthora cinnamomi (a soil-borne water mould which infects the roots of native plants); Batrachochytrium dendrobatidis, a fungus which causes chytridiomycosis in frogs (amphibian chytrid disese); psittacine circoviral (beak and feather) disease infecting parrots, and myrtle rust (a disease of native Myrtaceae plants caused by the exotic fungus Austropuccinia  psidii (initially identified as Uredo rangelii). The rapid spread and extraordinary impact of this pathogen poses a significant threat to the Gondwana Rainforests and has been attributed to the decline of Rhodamnia rubescens and Rhodomyrtus psidioides, which are now listed in both NSW and QLD as Critically Endangered (Threatened Species Scientific Committee, 2019; QLD Nature Conservation Act 1992). R. psidioides is one of the ten most seriously affected species in southeast Queensland with numerous reports of localized extinction in that area (Makinson, 2018). Lenwebbia sp. Main Range was also listed a critically endangered in NSW in October 2020, with Myrtle rust a key factor in the deteriorating status of this species (Threatened Species Scientific Committee, 2020). 

In the austral spring and summer of 2020 wildfire impacted an estimated 51% of the surface area of the World Heritage site (NSW DPIE, 2020). Fires occurred across the site including in three Queensland parks (Main Range, Mount Barney, Lamington) and sixteen NSW reserves (Border Ranges, Tooloom, Nightcap, Mount Clunie, Mount Nothofagus, Gibraltar Range, Washpool, New England, Werrikimbe, Oxley Wild Rivers,  Barrington Tops and Mount Royal national parks and Wiili Willi, Mount Hyland, the Castles and Mount Seaview nature reserves). In several areas the fires burnt into rainforest that had previously never recorded a fire and were generally considered resistant to fire. The fires were preceded by a prolonged drought and were coincident with a period of above average temperatures and below average rainfall (Australian Bureau of Meteorology Special Climate Statement 71, September 2019). The report notes that "rainfall totals that were 50 percent below average, and some locations had their driest January to August period on record since (at least) 1900". The long term drought and above average daily mean temperatures were predicted by climate change models, and they are directly linked to the extent and severity of the wildfires (NSW DPC, 2020).  
The following list includes species identified as attributes of World Heritage values. Plant species considered  to be affected include Bertya ernestiana, Brachyscome ascendens, Bulbophyllum weinthalii subsp. weinthalii, Clematis fawcetti, Euphrasia bella, Floydia praealta, Leionema elatius subsp. beckleri, Leptospermum barneyense, Leucopogon recurvisepalus, Macadamia tetraphylla, Marsdenia coronata, Marsdenia longiloba, Pseudanthus pauciflorus subsp. pauciflorus, Pultenaea whiteana, Sarcochilus hartmannii, Tetramolopium vagans, Westringia rupicola,  Ziera collina, Zieria montana. Animal species considered to be affected include: Birds: Eastern bristlebird (Dasyornis brachypterus), rufous-scrub bird (Atrichornis rufescens), Coxen's fig-parrot, Alberts lyrebird (Menura alberti), plumed frogmouth (Podargus ocellatus), masked owl (Tyto novaehollandiae), powerful owl (Ninox strenua), black-breasted button quail (Turnix melanogaster). Mammals: Hastings river mouse (Pseudomys oralis), New Holland mouse (Pseudomys novaehollandiae), brush-tailed rock wallaby (Petroogale penicillata), long-nosed potoroo (Potorous tridactylus), spotted quoll (Dasyurus maculatus), greater glider (Petauroides volans), koala (Phascolarctos cinereus), black-tailed marsupial mouse (Antechinus arktos). Reptiles: three-toed snake-tooth skink (Coearanoscincus reticulatus), Oakview leaf-tailed gecko (Phylurus kabikabi). Frogs: red and yellow mountain frog (Philoria kundagungan), sphagnum frog (P. sphagnicolus), Pugh's mountain frog (P. pughi), Loveridgei's mountain frog (P. loveridgei), giant barred frog (Mixophyes iteratus), Fleay's barred frog (M. fleayi), stuttering frog (M. balbus), Davies' tree frog (Litoria daviesae), glandular frog (L. subglandulosa), cascade treefrog (L. pearsoniana), peppered frog (L. piperata), red-eyed green tree frog (L. chloris). Fish: Osylean pygmy perch (Nannoperca oxleyana). More detailed assessment of the impacts of fires on the Outstanding Universal Value of the site is underway (State Party of Australia, 2020). Management of fire in a biodiverse mosaic of forest types is challenging. The serial nature of the World Heritage site, and high boundary to area ratio, increases the complexity of fire management, which is undertaken in consultation with neighbours and the bushfire management authorities in each state. Recent research has demonstrated the flammability of rainforest fuels in cool temperate rainforests, highlighting the critical role of moisture levels in protecting rainforest communities from fire (Peacock, unpublished data). A recent assessment of current and projected change in lifting condensation level (cloud base) suggests additional moisture loss from a rising cloud base is possible (Narsey et al., 2020).
 

A variety of invasive plant species have been recorded including bitou bush (Chrysanthemoides monilifera subsp.rotundata) and boneseed (Chrysanthemoides monilifera subsp. monilifera) which affect coastal areas; mistflower (Ageratina riparia), crofton weed (Ageratina adenophora), lantana (Lantana camara), blackberry (Rubus fructicosus), camphor laurel (Cinnamomum camphora), broad-leaved privet (Ligustrum lucidum) and small-leaved privet (L. sinense),  Kahili ginger (Hedychium gardnerianum), madeira vine (Andredera cordifolia), moth vine (Araujia sericifera), cat's claw creeper (Macfadyena unguis-cati) and others. Scotch broom (Cytisus scoparius) is a particular problem in the southernmost part of the World Heritage site. Management response to these invasive species includes implementation of Threat Abatement Plans for those listed as key threatening processes and pest management plans in national parks. Weeds able to establish in full shade (i.e. exploit intact rainforest) and affect the canopy are possibly the group of greatest threat to the site, while weeds in shade intolerant groups are most likely to be a threat to riparian edges and fragmented remnants (DECCW, 2010). High biomass weeds including invasive grasses and Lantana can increase fire risk, particularly along forest edges. Areas of fire affected rainforest where the rainforest has had large scale impacts such as canopy loss are now carrying a vastly increased surface layer weed load of relatively common weed species. The long- term effect on the recovery of the rainforest by these pioneer weed species is unknown (IUCN Consultation, 2020c).  

The Gondwana Rainforests of Australia is a serial World Heritage site comprised of eight separate groups of reserves, containing 40 component parts. The Gondwana Rainforest reserves contain the major remaining areas of rainforest in north-east New South Wales and south-east Queensland and are disjunct in places due mainly to the naturally fragmented distribution of rainforest in this part of Australia. Some of the reserves are very small, but almost all have some connectivity to neighbouring protected areas, often with the same or very similar values. The area to boundary ratio of fragmented reserves increases exposure to threats such as weed and pathogen invasion, changes in the microclimate of otherwise intact rainforest, and potentially has negative impacts on natural biological processes (including altitudinal and latitudinal migration in response to climate change) (IUCN Consultation, 2017). On balance the Outstanding Universal Value of the site is secured through the large reserves, which represent the majority of the World Heritage site (Queensland State of the Environment Report, 2017). This could be improved by progressing the extension to the World Heritage site, including previously assessed contiguous protected areas with World Heritage attributes (IUCN Consultation, 2020c).

Introduced animals include fox (Vulpes vulpes), rabbit (Oryctolagus cuniculus), feral cat (Felis catus), goat (Capra hircus), wild dog (Canis lupus familiaris or hybrids with Canis lupus dingo), feral pig (Sus scrofa), feral deer (Cervidae spp.), feral horses (Equus caballus) and others. Cane toads (Rhinella marina) are increasing in numbers in Border Ranges National Park. All these animals have an impact on the reserves either by displacement, predation or competition and their management is included in management plans (NPWS, 1998; NPWS, 2005; DERC, 2011). Straying stock (cattle, Bos taurus) pose a problem in some parts of the site (Chester and Bushnell, 2005). The introduced fish, plague minnow (Gambusia holbrooki), occurs in many streams. There are some locations where non-native sport fish (trout and salmon) are released into streams that flow into the reserves or the fish migrate upstream. The impact of these fish on native aquatic assemblages remains a matter for investigation. 
Strategies to manage these pest animals are incorporated in national parks management plans and implemented in cooperation with neighbours as part of tenure blind approach to pest management through regional pest management strategies and plans in NSW (IUCN Consultation, 2017). A controversial exotic invader is also the European Bee, which competes for nectar with native nectivores and occupies tree hollows that are used by native animals.

A consequence of the wildfires of 2019-2020 is that in many locations the density of the vegetation was greatly reduced. This favours introduced predators and compromises the capacity of the native animals to escape and seek shelter. This is a cumulative impact of the fires, animals that survived the fire needed to move more widely to obtain food and shelter, but are prone to predation in the opened vegetation communities.