Small-flowered Snottygobble (Personia micranthera) Interim Recovery Plan 2003-2008

Interim Recovery Plan No. 145
Gillian Stack and Andrew Brown
Department of Conservation and Land Management, WA, 2003

1. Background

History

Fred Lullfitz 1 made the type collection of Persoonia micranthera from the Stirling Range in 1964 and Peter Weston 2 described the species in 1985. Surveys between 1980 and 1997 failed to find plants outside the small area of known populations.

An intense fire in April 1991 burnt all the known populations of Persoonia micranthera on Bluff Knoll leaving just three adult plants intact in a small unburnt pocket (Population 3). Surveys were conducted in 1994, 1995 and 1996 to assess post-fire regeneration. Although no seedlings were found at that time (Barrett 1996), two seedlings were recorded at Population 1 and approximately 150 seedlings were recorded at Population 3 in 1997. An additional population of 39 juvenile plants was located in 2000 (Population 4), and at that time 2 juveniles were discovered at Population 2.

In October 2000 another intense fire burnt most populations. However, 6 mature plants survived the fire and approximately 350 juveniles were located.

A small number of plants that had germinated in response to the 1991 fire flowered for the first time in 2001.

A three year IRP was prepared for the species in November 1999 and expired in October 2002. This revised IRP, for 5 years, replaces that plan.

Description

Persoonia micranthera is a low growing shrub 10-40 cm tall. The young branchlets are moderately hairy, with flattened leaves, 4 to 8cm long and 8 to 30 mm wide, with slightly recurved margins. The leaves are held horizontally, often in clusters of 2 to 5 separated by long internodes. Inflorescences have 4-15 yellow flowers, with the main axis of the inflorescence being 1-6 cm long. Flower segments are 1-12 cm long, pointed, and moderately hairy outside (Brown et al. 1998).

Distribution and habitat

Persoonia micranthera occurs at high altitudes in the eastern section of the Stirling Range. Habitat is low dense heath and scrub on a rocky shallow soil over schist and is part of the Critically Endangered Threatened Ecological Community (TEC) "Eastern Stirling Range Montane Heath and Thicket Community". Associated species include: Kunzea montana, Beaufortia anisandra, Sphenotoma sp. Stirling Range, Andersonia echinocephala, Darwinia spp., Banksia solandri, Banksia brownii and Dryandra concinna (Barrett 1999).

Other species of threatened flora that occur in the community are Dryandra montana, Sphenotoma drummondii, Darwinia collina, D. squarrosa, Banksia brownii, Leucopogon gnaphalioides, Deyeuxia drummondii and Andersonia axilliflora (Barrett 1999).

Biology and ecology

Little is known about the biology or ecology of Persoonia micranthera but it appears that the species is highly susceptible to both dieback and fire.

It appears that Persoonia micranthera, like other montane species (eg Andersonia axilliflora), takes a long time to reach reproductive maturity. Several plants at Population 4 were carrying fruit for the first time in 2001, 10 years after the area was burnt in the 1991 fire. The level of viability of seed in those fruits is unknown.

Persoonia species are generally difficult to propagate (personal communication G. Keighery 3), and P. micranthera has shown a variable success rate from cuttings, ranging from 0% to 100% (personal communication A. Shade 4).

Threats

Persoonia micranthera was declared as Rare Flora in November 1997 and ranked as Critically Endangered (CR) in November 1998. It currently meets World Conservation Union (IUCN, 2000) Red List Category CR under criteria B1ab(i,ii,iii,v)+2ab(i,ii,iii,v), C2a(i) and D, due to the extremely small number of adult plants, the fragmented nature of populations, a decline in habitat quality due to fire and Phytophthora and a decline in adult plant numbers. Only six mature plants are currently known from four populations, with many subpopulations represented only by juveniles. All populations are threatened by dieback, and most populations have been affected by fire in 1991 and 2000. Lesser threats include grazing and damage through recreational use of the National Park.

  • Phytophthora cinnamomi is a major threat to all populations of the species. Persoonia micranthera is moderately to highly susceptible to the pathogen, which kills susceptible plants by invading their root systems and severely reducing their ability to take in water and nutrients. Many other species in the Montane Heath and Thicket Community are also affected by the pathogen which spreads through root-to-root contact and through free water flow. It spreads most quickly downhill but is also capable of moving uphill. Notably, it also spreads through movement of infected soil, by foot (see Recreational Use) or by vehicle during firebreak and vehicle track use and maintenance. P. cinnamomi thrives best in mild moist conditions such as those produced by spring, autumn or summer rainfall. The interactions of fire and dieback are not completely understood but field observations suggest that fire in areas where the disease is already present increases site susceptibility to P. cinnamomi (personal communication- S. Barrett 5).
  • Wildfire may adversely affect the long-term viability of Persoonia micranthera populations. A fire in 1991 killed all but three adult plants but stimulated germination of soil stored seed. Seedlings take a minimum of 10 years to become mature (reproductive) and most plants assessed at Populations 1a and 4 had not flowered 11 years post-fire. A second fire swept through most populations in October 2000, killing most juveniles at Populations 1b, 1c, 1d and 3. However, germination of soil-stored seed occurred in Populations 1d and 3, showing that some seed had persisted despite the lack of mature plants. It is thought that, if a third major fire occurred before seed is produced in significant quantities, the soil seed bank would be seriously depleted, and if plant numbers continue to decline due to P. cinnamomi infection, the probability of species extinction is high.
  • Grazing by herbivores has been noted on the habitat and some individual Persoonia micranthera plants at Populations 1a and 4, but the identity of the herbivore is unclear and the impact low
  • Recreational Use of the Stirling Range is high. Uses include hiking, camping and rock climbing, which increase the threats of disease introduction/movement, trampling, secondary track formation and addition of nutrients to naturally nutrient-poor soils. A major recreational use of the eastern Stirling Range is a well known bushwalk which runs from Ellen Peak to Bluff Knoll. This is usually completed in two to three days, thus requiring camping in the area overnight. Most visitors do not deviate from the main ridge, but assessment, monitoring and regulation of visitor numbers may be necessary to ensure Persoonia micranthera populations and high priority areas of the Montane Heath and Thicket Community are not compromised.
5 Sarah Barrett, Rare Flora Officer, the Department's Albany Work Centre
Summary of population information and threats
Pop. No. & Location Land Status Year/No. plants Condition Threats
1a. Stirling Range NP, Bluff Knoll National Park 1990 1
2002 0 (100+)
Moderate Disease, fire, minor grazing, recreational use
1b. Stirling Range NP, Bluff Knoll National Park 1999 1 (7)
2001 0
Poor - burnt in 2000 fire Disease, fire, recreational use
1c. Stirling Range NP, Bluff Knoll National Park 1999 0 (6)
2002 0 (2)
Poor - burnt in 2000 fire Disease, fire, recreational use
1d. Stirling Range NP, Bluff Knoll National Park 1999 0 (32)
2002 0 (100+)
Moderate Disease, fire, recreational use
2. Stirling Range NP, Coyanerup Peak National Park 1980 'common'
2002 0
Poor Disease, fire, recreational use
3. Stirling Range NP, Isongerup Peak National Park 1997 3 (150+)
2002 1 (100+)
Moderate Disease, fire, recreational use
4a. Stirling Range NP, East Bluff National Park 2000 0 (16)
2002 4 (18)
Moderate Disease, fire, minor grazing, recreational use
4b. Stirling Range NP, East Bluff National Park 2000 0 (23)
2002 0 (10+)
Moderate Disease, fire, recreational use
4c. Stirling Range NP, East Bluff National Park 2001 0 (1) Moderate Disease, fire, recreational use

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 Persoonia micranthera comprises:

  • the area of occupancy of known populations;
  • areas of similar habitat within 200 metres of known populations, i.e. low dense heath and scrub on a rocky shallow soil over schist at high altitudes (these provide potential habitat for natural range extension);
  • vegetation that links populations (the surrounding National Park is necessary to allow pollinators to move between populations); and
  • additional occurrences of similar habitat that do not currently contain the species but may have done so in the past (these represent possible translocation sites). Currently, no Phytophthora cinnamomi free sites are known.

Habitat critical to the survival of the species, and important populations

Given that this species is listed as Critically Endangered it is considered that all known habitat is habitat critical. In addition, all populations, including future translocated populations, are or will be considered important to the survival of the species.

Benefits to other species/ecological communities

Recovery actions implemented for Persoonia micranthera will improve the status of the Critically Endangered Eastern Stirling Range Montane Heath and Thicket Community in which it occurs. It will also improve the status of other threatened flora taxa including Dryandra montana, Sphenotoma drummondii, Darwinia collina, D. squarrosa, Banksia brownii, Leucopogon gnaphalioides, Deyeuxia drummondii and Andersonia axilliflora.

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 Persoonia micranthera 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 specific areas affected by this plan.

Social and economic impacts

The implementation of this recovery plan is unlikely to cause significant adverse social and economic impacts. All populations occur in the Stirling Range National Park.

Evaluation of the Plans Performance

The Department of Conservation and Land Management (DCLM), in conjunction with the Albany District Threatened Flora Recovery Team will evaluate the performance of this IRP. The plan is to be reviewed within five years of its implementation. Any changes to management / recovery actions will be documented accordingly.

Guide for decision-makers

Section 1 provides details of current and possible future threats. Any on-ground works (clearing, firebreaks, walk tracks etc) in the immediate vicinity of Persoonia micranthera will require assessment. On-ground works should not be approved unless the proponents can demonstrate that they will not have an impact on the species, its habitat or potential habitat.