Threatened Species and threatened ecological communities
Advice to the Minister for the Environment and Heritage from the Threatened Species Scientific Committee (TSSC) on Amendments to the list of Threatened Species under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)
Dinaphorura tooheyensis (Toohey Forest Collembola, a Springtail)
The Toohey Forest Collembola is a soil invertebrate that is known to occur in Toohey Forest, Brisbane, Queensland. Toohey Forest is a eucalyptus woodland reserve of approximately 655 hectares. The forest is situated within an urban area on the south side of Brisbane, within the city limits.
The species has only been located and surveyed in a one hectare site in the moist, shallow, red-yellow podzolic loamy soil of Toohey Forest in an area where Needlebark Stringybark (Eucalyptus planchoniana) woodland is the dominant vegetation (Rodgers and Greenslade, 1996).
The species is not listed under the EPBC Act nor is it listed as threatened under the Queensland Nature Conservation Act 1992.
TSSC judges the species not to be eligible for listing under the EPBC Act. The justification against the criteria is as follows:
There is no evidence available against this criterion.
Therefore the species is not eligible for listing under this criterion.
The published work to date on the species has only been on a single hectare site within the Toohey Forest where the species was first located and identified. Evidence suggests that no other areas in Toohey Forest have been surveyed for this species. Although areas within southern Queensland have been surveyed for soil invertebrates, it appears that there have been no directed surveys focused on the Toohey Forest Collembola in similar ecosystems outside of Toohey Forest.
The potential distribution of the Toohey Forest Collembolais uncertain as the micro-habitat requirements of this species have not yet been fully determined and described. It is possible that a combination of very specific factors make an area suitable as Toohey Forest Collembola habitat, or the species may be more adaptable to a range of different environments and therefore more widespread. The one hectare site where the Toohey Forest Collembola was located is an area of Eucalyptus planchoniana forest. Although Eucalyptus planchoniana occurs outside of Toohey Forest in northern New South Wales and southeastern Queensland, a more useful indicator of potential habitat is likely to be microenvironment parameters such as soil moisture. Rodgers (1997) found that abundance of the Toohey Forest Collembola was positively correlated with soil moisture content and not associated with four different plant species that were examined. Further field surveys are required and the ecological parameters of habitat for the Toohey Forest Collembola need to be defined before the range and distribution of this species can be determined.
Collembola are sensitive to disturbance and it is claimed that it is likely that the Toohey Forest Collembola will require undisturbed sites for habitation. Collembola generally feed on micro-organisms associated with the root zone and decomposing organic matter. Changes in the vegetation on the surface therefore may affect the ecological relationships of the microenvironment below the soil surface.
Due to its urban surrounds, the integrity of the forest area is being impacted by activities and development around the perimeter of the park and visitor impacts such as erosion of tracks due trail bike riding. The environmental integrity of the forest is also at risk from weed species such as Lantana spp. and Camphor laural (Cinnamomum camphora). The forest is cut by two major road corridors (Toohey Road, the south-east freeway) and a power easement passes through the park. Although there is a record kept of the burning regime, there are no detailed studies of the on-going ecological effects of such fires and it is claimed that the fire regime is altering the forest ecology by resulting in dense understorey regrowth being dominated by Pultenaea, Allocasuarinas and Acacias. However it is not known how these impacts on the forest will affect the Toohey Forest Collembola.
The geographic range and distribution of the Toohey Forest Collembola is not known. The number of populations is also not known.The effect of activities in the park and potential threats to the species are not known.Therefore the species is not eligible for listing under this criterion.
Rodgers (1997) surveyed Collembolan species from forty plots within a one hectare site of Toohey Forest. Samples were taken from the red-yellow podzolic soils in areas of Eucalyptus planchoniana woodland and showed that the Toohey Forest Collembola was the forth most common species of the 31 Collembola species surveyed. Twenty five of the forty plots contained the genus Dinaphorura (the proportion of Dinaphorura tooheyensis is not specified). Maximum abundance of the genus Dinaphorura was recorded as 1304 individuals per square metre in the top 50mm of soil. Based on the density data it has been estimated that the population is 100,000 to 200,000 mature individuals.
There is no subsequent information available from the initial survey to be able to determine a population change.
Therefore, the species is not eligible for listing under this criterion.
The estimated total number of individuals is 100,000 to 200,000 mature individuals.
Therefore, the species is not eligible for listing under this criterion.
There is no evidence available against this criterion.
Therefore, the species is not eligible for listing under this criterion.
The geographic distribution of the Toohey Forest Collembola is uncertain as only one field survey has been published for the species. No threatening processes have been clearly identified for this species. The environmental integrity of Toohey Forest may be at risk from neighbouring development and weed invasion, although it is uncertain as to how this will impact on the species or the site where the Toohey Forest Collembola has been identified. If the species is restricted in distribution, it would be vulnerable to random catastrophic events. However there is limited population information available on the species, so it is not possible to determine if the species has undergone any past fluctuations or declines. Accurate determination of its conservation status requires refinement of both its distribution and population status. The species is not eligible for listing.
TSSC recommends that the species Dinaphorura tooheyensis is not eligible for inclusion in the list referred to in section 178 of the EPBC Act.
Rodgers, D. (1997) Soil Collembolam (Insecta: Collembola) assemblage structure in relation to understorey plant species and soil moisture on a eucalypt woodland site. Memoirs of the Museum of Victoria 56(2): 287-293
Rodgers, D. & Greenslade, P. (1996). A new diagnosis for Dinaphorura (Collembola : Onychiuridae : Tullbergiinae) and description of new species from Australia. Journal of Natural History 30: 1367-1376.