Boscabel Conostylis (Conostylis setigera subsp. dasys) Interim Recovery Plan 2003-2008
Interim Recovery Plan No. 150
Bethea Loudon
Department of Conservation and Land Management, WA, 2003
1. Background
History
S.D. Hopper first collected Conostylis setigera subsp. dasys from a road reserve north of Kojonup in October 1976. The holotype was collected in November 1985 from the same location, also by Hopper. Several subpopulations were located in close proximity in the following years and a second population almost 2km to the west, in November 1990.
The subspecies was named after the Greek word dasys meaning 'shaggy', referring to the leaf hairs (Hopper et al 1987).
In a number of locations where the soil type changes to white sand with some gravel on lower slopes, Conostylis drummondii, also Declared Rare Flora, can be found growing with Conostylis setigera subsp. dasys).
Description
Conostylis setigera subsp. dasys is a tufted perennial herb 15-30cm in height. The distinctive leaves are flat with rough, white shaggy hairs over the entire surface and margins, and are coarse to touch. The typical yellow Conostylis inflorescence appears on stalks that are usually shorter than the leaves, in heads of 5-10 flowers. Flowering occurs between October and November with flowers changing to red with age (Hopper et al 1987).
Conostylis setigera subsp. dasys differs from subsp. setigera in its later flowering season and the condition and/or presence of hairs on the leaf lamina (subsp. setigera flowers August to October and has glabrous leaf lamina except for the margins or with sparse fine hairs, compared to the presence of shaggy, scabrid hairs over entire leaf surface of subsp. dasys) (Hopper et al 1987).
It is possible that subsp. dasys may be elevated to species level some time in the future based on recent molecular work (pers. comm. S. Hopper1 via A. Brown2, 2003).
Distribution and habitat
Conostylis setigera subsp. dasys is currently known from just two populations north-northwest of Kojonup. At both locations it grows with Allocasuarina humilis, Eucalyptus marginata, E. wandoo, Dryandra nivea and Petrophile serruriae in gravelly loam or gravelly sand.
Biology and ecology
Only small amounts of seed could be collected from plants in December 1999. Many fruits were predated and seed aborted (pers. comm. A. Cochrane ³, 2002). Initial germination results recorded 0% and 11%, indicating that seed set and viability may be low in this species, however the low seed numbers (~10 from each site) used in the tests may also have had an affect on this outcome. Cochrane stated that Conostylis release their seed at any time once mature, making it difficult to collect - a case of needing to be in the right place at the right time. It would appear that the species produces low amounts of seed that are passively dispersed each season, as well as being subject to high rates of abortion and predation. High rates of predation are seen in other Genera of the Haemodoraceae Family (pers. comm. A. Cochrane ³, 2002/2003).
Flower colour and size would indicate that Conostylis setigera subsp. dasys is insect pollinated. Hopper suggested that the species would almost certainly be pollinated by native bees (Halactid). Other Conostylis species are pollinated by these bees (pers. comm. S. Hopper ¹ via A. Brown ², 2003).
It is difficult to determine plant ages due to the varying heights of flowering plants; on occasion even some small plants with only a few leaves had evidence of flowering in the past season. There is also a limited few that are obviously of considerable age being quite dense clumps. There appears to be a mixture of young, small plants as well as mature dense tufts of plants.
A study on the germination of four native species of Western Australia using plant-derived smoke, found that the application of diluted and full strength smoke water substantially improved the germination of Conostylis setigera (subsp. setigera) (Tieu and Dixon, 1990). It is quite possible that the same results would be seen in C. setigera subsp. dasys, suggesting that the taxon may respond well to fire.
Factors and constraints relevant to the long-term survival and future population growth of the taxon may include the species' breeding system/pollinator activity or vector, seed production/viability and predation, along with grazing by rabbits, and restriction to the particular soil/slope/topography and vegetation types (ie C. setigera subsp. dasys appears to be excluded from heavy loamy soils and deep sand).
¹ Steve Hopper, Chief Executive Officer, Botanic Parks and Gardens Authority.
² Andrew Brown, Coordinated Threatened Flora, WATSCU.
³ Anne Cochrane, Manager, The Departments Threatened Flora Seed Centre.
Threats
Conostylis setigera subsp. dasys was declared as Rare Flora and ranked Endangered November 1991. In September 1999 the subspecies was upgraded to Critically Endangered. It currently meets World Conservation Union (IUCN, 2000) Red List Category 'CR' under criteria A1(a); B1ab(iii)+2ab(iii) due to an estimated decline in the number of mature individuals of 90% over three generations, a geographic range of less than 100 km2 and area of occupancy less than 10 km2, a severe fragmentation of populations (just two known) and a continuing decline in the quality of habitat. The main threats are the taxon's narrow distribution, habitat degradation due to the effects of Phytophthora cinnamomi, rabbits and poor seed production/viability.
- Limited geographical range is a threat to the taxon as single catastrophic events have the potential to cause extinction.
- Insecure tenure could result in a change of land ownership and may place populations at risk from inappropriate future management practices.
- Rabbits appear abundant in the vicinity of the west portion of Population 1B and at 1D where grazing of plants is evident. Lower plant numbers in the vicinity of powerlines (west portion of Population 1B) may be the result of rabbits as high grazing pressure and evidence of higher rabbit numbers is clearly visible where the vegetation is quite open with considerable bare ground. High levels of grazing of native grasses and sedges was observed with plants chewed back to small, dense clumps at ground level. Where plants occur in natural, undisturbed bush that is denser, the rare species was not grazed. Numerous rabbit warrens occur near Population 1D. Rabbit control should be undertaken at 1D and west part of 1B near powerlines, with monitoring of other areas for evidence of increased rabbit numbers and grazing. Kangaroos do not appear to be a problem, although numbers may be high, as grazing of the Declared rare Flora (DRF) is linked to high incidence of rabbit activity.
- Fire response of Conostylis setigera subsp. dasys plants is not known. The rest area/parking bay adjacent to Population 1C has evidence of campfires which may pose a threat if they escape, both directly to individual plants and by altering the habitat through the establishment of weeds. Research into fire response is required to determine effects on mature plants.
- Road maintenance such as road widening, slashing of road verge vegetation, weed control, grading of road shoulders and backslopes and construction of drains have the potential to affect Populations 1A and 1D. Relevant management authorities have been informed of the location of the populations and the threatened nature of the species.
- Powerline maintenance including vegetation pruning or removal from beneath powerlines and vehicular access directly beneath poles and overhead wires have the potential to impact on the western portion of Population 1B. The respective management authority is aware of the presence of the DRF and its threatened nature. Environmentally Sensitive Area (ESA) markers have been placed on power poles in the vicinity of the plants and special management instructions provided by a consultant to the managing authority during a recent investigation involving the occurrence of DRF beneath power lines.
- Rest area/parking bay maintenance such as grading, widening and weed control have the potential to impact on the species at Population 1C. The relevant land manager has been informed of the location of the population and the threatened nature of the species.
- Phytophthora cinnamomi or possibly Armillaria may be impacting on the Jarrah (Eucalyptus marginata) and parrot bush (Dryandra sessilis). There are localised signs of recent and old deaths of these species, indicating that a pathogen of some sort may be involved. It is not known whether or not Conostylis setigera subsp. dasys is susceptible to Phytophthora cinnamomi. Testing of the species' susceptibility to this pathogen is required. However, at present it does not appear to be affected with only one dead plant observed at Population 2. Even if the Conostylis is not directly susceptible, a decline and degradation of the vegetation and habitat in which it occurs may impact on the rare species in the long term. Interpretation and testing for the presence of Phytophthora cinnamomi or Armillaria at all sites is required.
- Weeds are not a problem at present at either of the populations. However, monitoring needs to continue so that weeds in rest area/parking bay (1C) and along the road reserve of Population 1A (west verge) do not proliferate and impact on the Conostylis by competing for space, nutrients and moisture. All other sites are relatively pristine pieces of bush. Liaison with the Shire may be required regarding the issue of weed invasion and control at Population 1C.
- Gravel extraction has not occurred near Population 1C for many years (perhaps since before the population was first surveyed in 1988) with old pits immediately to the east of where the plants are currently growing. However, there is a potential for extraction to occur in the future. Liaison with the Shire of Kojonup on the matter may be required.
| Pop. No. & Location | Land Status | Year/No. plants | Condition | Threats |
|---|---|---|---|---|
| 1a. NNW of Kojonup | MRWA road reserve | 1987/45 1988/17 (partial count) 1993/20 1998/26 1999/24 2003/348 |
Healthy Healthy Healthy Healthy Healthy |
Road maintenance |
| 1b. NNW of Kojonup | Private Property | 1987/0 1988/1000 1997/2 1998/0 2001/23 2003/175 |
Healthy Healthy |
Phytophthora?, powerline maintenance, rabbits |
| 1c. NNW of Kojonup | Shire gravel reserve & rest area | 1998/50 1999/31 1999/30 2003/465 |
Healthy Healthy |
Parking bay/rest area maintenance, potentially weeds in centre of rest area, inappropriate fire, Phytophthora? |
| 1d. NNW of Kojonup | Shire road reserve | 1992/2 2003/17 |
Undisturbed Healthy |
Road maintenance, rabbits |
| 2. NW of Kojonup | Unvested Crown Land - Townsite | 1990/50 1997/100 1998/20 2003/340 |
Undisturbed Healthy Healthy Healthy |
Phytophthora? |
Critical habitat
Critical habitat is habitat identified as being critical to the survival of a listed threatened species or listed threatened ecological community. Habitat is defined as the biophysical medium or media occupied (continuously, periodically or occasionally) by an organism or group of organisms or once occupied (continuously, periodically or occasionally) by an organism, or group of organisms, and into which organisms of that kind have the potential to be reintroduced. (Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)).
The critical habitat for Conostylis setigera subsp. dasys comprises:
- the area of occupancy of known populations;
- areas of similar habitat within 200 metres of known populations, i.e. gravelly loam or gravelly sand in Eucalyptus marginata(dominant)/wandoo woodland over low heath of Allocasuarina humilis, Dryandra nivea and Petrophile serruriae (these provide potential habitat for natural range extension);
- additional occurrences of similar habitat nearby that do not currently contain the taxon but may have done so in the past (these represent possible translocation sites).
Habitat critical to the survival of the species, and important populations
Given that this subspecies is listed as Critically Endangered it is considered that all known habitat for wild and any future translocated populations is habitat critical and that all populations are important.
Benefits to other species/ecological communities
There are no threatened ecological communities in the immediate vicinity Conostylis setigera subsp. dasys. One other threatened plant (Conostylis drummondii) is known to occur in the area of both populations. Recovery actions, such as rabbit control, implemented to improve the quality or security of the habitat of Conostylis setigera subsp. dasys, will also benefit Conostylis drummondii and the remnant bushland habitat in which they both occur.
International Obligations
This plan is fully consistent with the aims and recommendations of the Convention on Biological Diversity, ratified by Australia in June 1993, and will assist in implementing Australia's responsibilities under that Convention. However, as Conostylis setigera subsp. dasys is not listed under any international agreement, the implementation of other international environmental responsibilities is not affected by this plan.
Role and interests of indigenous people
There are no known indigenous communities interested or involved in the management of areas affected by this plan.
Social and economic impacts
The implementation of this recovery plan is unlikely to cause significant adverse social and/or economic impacts. Populations occur on road reserves, a gravel reserve, unvested crown land and private property. Negotiations have resulted in a voluntary agreement that the area directly supporting the species on private property will be left uncleared.
Evaluation of the Plans Performance
The Department of Conservation and Land Management (DCLM), in conjunction with the Recovery Team will evaluate the performance of this IRP. In addition to annual reporting on progress with listed actions and comparison against the criteria for success and failure, the plan is to be reviewed within five years of its implementation.
Guide for decision-makers
Section 1 provides details of current and possible future threats. Any on-ground works (clearing, firebreaks etc) in the immediate vicinity of Conostylis setigera subsp. dasys will require assessment. On ground works should not be approved unless the proponents can demonstrate that they will not have an impact on the taxon, its habitat or potential habitat.