|Scientific Name:||Araucaria bidwillii|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer/s:||Farjon, A. & Mill, R.|
The extent of occurrence (EOO) is approximately 11,000 km2 with 99% of this in southeastern Queensland. Although the EOO is within the threshold for Vulnerable, A. bidwillii is known from more than 10 locations and the population is not considered to be severely fragmented. Although significant past decline has occurred within the last three generations it has not been possible to quantify its extent. No significant decline in EOO, AOO, quality of habitat, number of locations or subpopulations or number of mature individuals is is currently evident or predicted in the near future. On this basis, A. bidwillii is assessed as Least Concern. Although the overall assessment is Least Concern, the subpopulations at Mt Lewis and Cannabullen Falls contain few individuals and are very restricted in their extent and as such, are highly susceptible to stochastic events such as fire. Genetic analysis indicates that these northern subpopulations are highly distinctive and there is a potential threat from outbreeding depression due to the widescale planting of ornamental and amenity trees that have originated from the southern subpopulations.
|Range Description:||Restricted to two areas in Queensland, Australia that are separated by over 1,000 km. The EOO is approximately 11,000 km2; 99% of this is in southeastern Queensland as the two northern localities (Mt Lewis and Cannabullen Falls) are very limited in their extent. The EOO, based on recent fieldwork (I. Smith unpubl. data) and reliable literature records (e.g. Pye and Gadek 2004), excludes the intervening area between the most northern locality in southern Queensland and Cannabullen Falls in northern Queensland.|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The isolated northern subpopulation has less than 100 mature individuals. Genetic investigations indicate that this population differs significantly from those in the south and that its conservation should be a priority. Southern subpopulations range in size from a few tens of trees to over 1,000. They are likely to be the remnants of an almost continuous larger population that stretched from the coastal areas into the Bunya Mountains (Pye 2004).|
|Habitat and Ecology:||
Araucaria bidwillii is a large, emergent tree in subtropical rainforest on basaltic or other igneous substrates that is sometimes associated with A. cunninghamii. It occupies the ecotone between moist angiosperm-dominated forest and drier vine thickets with partly deciduous trees, particularly in the southern part of its disjunct range. The forest is divided into larger and smaller woods by ‘balds’, coarse grasslands or open savannas which form sharp boundaries with the forest patches. Annual precipitation is 1,100-1,400 mm in the southern area, with heavy rains in summer but with a dry season from April/May to September. In contrast to this, the northern populations lie close to the wettest part of the Australian continent, causing a more evenly distributed annual precipitation of 1,500-2,000 mm (Mill and Farjon in prep.).
Abundant seed is produced in ‘mast years’ at approximately three-year intervals. Seeds remain in the cone until after it falls off the tree; they may be dispersed by water flowing in creeks and gullies, rolling down a slope or by animal vectors such as the Mountain Brush-tail Possum, Trichosurus caninus (Smith et al. 2007)
|Major Threat(s):||Despite significant exploitation in the past, the main subpopulations in southern Queensland are not currently threatened. In some areas regeneration and expansion into disused pastoral and farming areas is occurring and the majority of the subpopulations are within protected areas. The subpopulations at Mt Lewis and Canabulen Falls contain few individuals and are very restricted in their extent and as such, are highly susceptible to stochastic events such as fire. Genetic analysis indicates that these northern subpopulations are highly distinctive and there is a potential threat from potential outbreeding depression due to the widescale planting of ornamental and amenity trees that have originated from the southern subpopulations.|
|Conservation Actions:||The majority of the remaining subpopulations and locations are within protected areas. One of these, the Bunya Mountains National Park, was the second national park to be established in Queensland, in 1908.|
|Citation:||Thomas, P. 2011. Araucaria bidwillii. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 07 December 2013.|
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