Western prickly honeysuckle (Lamberta echinata subsp. Occidentalis) Interim Recovery Plan 2003-2008

Interim recovery plan no. 133
Gillian Stack & Andrew Brown
Department of Conservation and Land Management, WA, 2003

1. Background

History

Greg Keighery and Neil Gibson made the first collection of Lambertia echinata subsp. occidentalis in October 1992. A number of surveys in Whicher Range, Swan Coastal Plain and other areas of similar habitat were then undertaken to locate additional populations. However, none were successful.

A hot fire occurred in the area of the population in 1993 but it is not known if Lambertia echinata subsp. occidentalis was affected and may have in fact been missed by the fire. It is expected that the taxon is killed by intense fire, as it does not have a lignotuber, however, the seven adult plants recorded in 1992 were all healthy in 1997.

In 1998 just four extant adult plants and seventeen juveniles were recorded for the wild population. A further two plants within the population were recorded as dead, presumably as a consequence of the plant pathogen Phytophthora cinnamomi.

The natural population and its habitat have been sprayed with phosphite to address the presence of dieback in the area. However, it now appears that species of Lambertia may not respond in the same way to treatment with phosphite as many other native species, with the uptake of phosphite into plant tissue appearing to be much greater and protection afforded much lower. In 2003, DCLM's Science Division will be investigating the response of a number of species of Lambertia (including Lambertia echinata subsp. occidentalis) to offer insight into how to better protect Lambertia species from dieback.

Translocations have been undertaken for this species in 1998, 2000, 2001 and 2002, with the majority of plants going into two Nature Reserves, recently acquired for this purpose. Other DRF ironstone species are also being translocated into these Nature Reserves.

In 2002, an additional 70 plants were found near the original population, increasing the number of mature plants known five-fold. This area has also been treated with phosphite to combat Phytophthora cinnamomi.

Description

Lambertia echinata is a small shrub with five-flowered terminal flower heads. Three subspecies of L. echinata are recognised: L. echinata subsp. echinata, L. echinata subsp. citrina and L. echinata subsp. occidentalis. L. echinata subsp. echinata is also ranked Critically Endangered.

Lambertia echinata subsp. occidentalis is a shrub to 3 m, branched at the base and with a few long erect floral branches. It has no lignotuber. There are two types of leaves. Vegetative leaves are entire and linear-lanceolate with a pungent apex. Floral leaves are smaller and may be entire or lobed with three to five points. Inflorescences are yellow and crowded at the ends of the branchlets.

Lambertia echinata subsp. echinata differs from the subspecies occidentalis in having pink-red flowers borne on short branchlets within the body of the plant. L. echinata subsp. citrina differs in that all vegetative and floral leaves have 3-5 rigid points. L. propinqua has been treated as a synonym of L. echinata subsp. citrina by Hnatiuk (1995). Population genetic studies suggest that, given the extreme genetic distance between L. echinata subsp. echinata and the other two subspecies, it may warrant species status (Obbens and Coates 1997).

Distribution and habitat

Lambertia echinata subsp. occidentalis is known from a single winter-wet area of shrubland over shallow sands over ironstone at the base of the Whicher Range. The ecological community, the 'Shrublands on southern Swan Coastal Plain Ironstones' in which the taxon occurs is also ranked Critically Endangered. There are a total of 13 occurrences of this species-rich plant community located on seasonal wetlands on ironstone on the Swan Coastal Plain near Busselton. L. echinata subsp. occidentalis has been translocated into three of those occurrences, although one of these has failed (all plants dead).

Native species common to the ironstone community are Kunzea aff. micrantha, Pericalymma ellipticum, Hakea sp. Williamson, Hemiandra pungens and Viminaria juncea, and the herbs Aphelia cyperoides and Centrolepis aristata (Gibson et al. 1994). Associated species include Hakea varia, Loxocarya magna and Chamelaucium roycei. Six additional species of Declared Rare Flora, three of which are also Critically Endangered, and five Priority taxa are found in the ironstone community in the vicinity of Lambertia echinata subsp. occidentalis. These are listed in the table below.

SPECIES STATUS RANK
Brachysema papilio DRF CR
Darwinia sp. Williamson DRF CR
Petrophile latericola ms DRF CR
Dryandra nivea subsp. uliginosa DRF EN
Dryandra squarrosa subsp. argillacea DRF EN
Chamelaucium roycei ms DRF VU
Andersonia ferricola ms Priority 1
Schoenus pennisetis Priority 1
Hakea oldfieldii Priority 3
Isopogon formosus subsp. dasylepis Priority 3
Loxocarya magna Priority 3

The IRPs for Critically Endangered flora that occur in the same area as Lambertia echinata subsp. occidentalis will be complementary to, and implemented in conjunction with this IRP and the IRP for the 'Shrublands on southern Swan Coastal Plain Ironstones' (English 1999).

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 Lambertia echinata subsp. occidentalis 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. Therefore no role has been identified for indigenous communities in the recovery of this species.

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 any translocated populations, are considered important to the survival of the species. Recovery actions include survey for further populations that would lead to the identification of additional habitat critical.

Benefits to other species/ecological communities

Lambertia echinata subsp. occidentalis occurs on the threatened ecological community "Shrubland Association on South Swan Coastal Plain Ironstones (Busselton Area)". Also, several other threatened plant taxa (Brachysema papilio, Petrophile latericola, Chamelaucium roycei ms, Dryandra squarrosa subsp. argillacea and Dryandra nivea subsp. uliginosa) will benefit from recovery actions put in place for the subspecies. Recovery actions for this subspecies will also improve the condition of the associated remnant bushland.

Social and economic impacts

The implementation of this recovery plan has the potential to have some minimal economic impact as the subspecies occurs in an area adjacent to a Mining tenement.

Evaluation of the Plan's Performance

The Department of Conservation and Land Management (DCLM), in conjunction with the South West Region Threatened Flora Recovery Team will evaluate the performance of this recovery plan. In addition to annual reporting on progress against the criteria for success and failure, the plan is to be reviewed within five years of its implementation. Any changes to management / recovery actions made in response to monitoring results will be documented accordingly.

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).

The critical habitat for Lambertia echinata subsp. occidentalis comprises:

  • the area of occupancy of the known population;
  • occurrences of similar habitat currently containing translocated plants of this species (these may in time become self-sustaining populations);
  • areas of similar habitat within 200 metres of the wild and translocated populations, i.e. winter-wet areas of shrubland over shallow sands over ironstone (these provide potential habitat for natural range extension);
  • corridors of remnant vegetation that link wild and translocated populations (these are necessary to allow pollinators to move between populations and are mainly road reserves);
  • the local catchment area (the species occurs on winter-wet areas which are dependent on the maintenance of local surface and ground water hydrology); and
  • additional occurrences of similar habitat that do not currently contain the subspecies but may have done so in the past (these represent possible translocation sites).

Biology and ecology

Lambertia echinata subsp. occidentalis is thought to be killed by fire and recruit from seed. Approximately 10 seedlings were located in 1996, three years after the last fire in the area. For comparison, Lambertia formosa appears to produce its maximum number of flowers two to three years after a summer fire, and seed production is thought to peak during this period. The seed of Lambertia echinata subsp. occidentalis is released from the two flat follicles as soon as it is ripe and germination rates are highest when the seed is fresh (Fox et al. 1987).

Like most other members of the genus, Lambertia echinata subsp. occidentalis is highly susceptible to the plant pathogen Phytophthora cinnamomi (dieback), which is present in the immediate area of the only known wild population (Keighery 1997). A site approximately 300 m to the south of the population near the access road tested positive for P. cinnamomi, and serious infections are known to have occurred upslope of the population in State Forest (Obbens and Coates 1997).

Despite the population being treated with phosphite in 2000 and 2001, and tissue analysis indicating phosphite concentrations within the plants to be relatively high, four plants died in 2001 all of which tested positive for P.cinnamomi. The levels of phosphite absorption were up to 10 times higher than other Proteaceous species in the same ironstone community. This raises questions of possible phosphite toxicity. Research will be conducted by DCLM in 2003 examining patterns of P.cinnamomi susceptibility and the uptake of phosphite in other Lambertia species (personal communication C. Crane ¹).

Seeds collected from the population have a high level of viability

There is currently little information available about pollinators, flower and fruit predation, germination triggers, the taxon's response to herbicide application or higher water tables due to land clearance. This information is essential to the recovery of Lambertia echinata subsp. occidentalis.

Threats

Lambertia echinata subsp. occidentalis was declared as Rare Flora in October 1996 and ranked as Critically Endangered in November 1998. It currently meets World Conservation Union (IUCN, 2000) Red List Category 'CR' under criteria A2c; B1+2ce; C2a; C2b and D (IUCN 1994) as it is known from a single wild population comprising less than 50 mature individuals, with a continuing decline in the quality of the habitat and the number of mature plants due to the pathogen Phytophthora cinnamomi. The main threats are disease, inappropriate fire regimes, mineral sand exploration, waterlogging, weeds and rabbit grazing.

  • Dieback disease is a serious threat to Lambertia echinata subsp. occidentalis as the subspecies is highly susceptible to Phytophthora cinnamomi (Keighery 1997) which is known to have impacted bushland near the population. Phosphite treatment was implemented in 2000 and 2001 but did not appear to afford the level of protection that it does for other taxa. Later analysis of four dead plants found to be infected with P. cinnamomi has shown them to have a relatively high concentration of phosphite in the plant tissues.
  • Canker (probably Armillaria luteobubalina) may have caused deaths of the DRF taxon Dryandra nivea subsp. uliginosa which grows near Lambertia echinata subsp. occidentalis. The susceptibility of Lambertia echinata subsp. occidentalis to this plant pathogen is unknown.
  • Inappropriate fire regimes are likely to affect the viability of the single population. Lambertia echinata subsp. occidentalis seed probably germinates after fire and, if this is the case, the soil seed bank would rapidly be depleted if fires recur before regenerating or juvenile plants reach maturity. However, it is likely that occasional fires are needed for the taxon to recruit.
  • Mineral sand extraction is to occur in privately owned land adjacent to the area of State Forest which contains Lambertia echinata subsp. occidentalis. Liaison between the proponent, DCLM and relevant government bodies is ongoing. Potential impacts include modification of the hydrology of the area and the proponent has designed an artificial recharge system to be monitored by several piezometers.
  • Waterlogging is a potential threat to the ironstone habitat in which Lambertia echinata subsp. occidentalis occurs (Tille and Lantzke 1990). Extensive clearing for agriculture in the area is likely to have increased surface runoff and recharge of the groundwater. Waterlogging is not an immediate threat but requires monitoring. Hirschberg (1989) measured levels of salinity in the groundwater in the area, and found the water near this population to range between 200-400 per litre total dissolved solids, which is reasonably fresh.
  • Weeds are a problem at all translocation sites. These partially cleared areas were purchased by DCLM in 1999 and are gradually being rehabilitated. Weeds suppress early plant growth by competing for soil moisture, nutrients and light. They also exacerbate grazing pressure and increase the fire hazard due to the easy ignition of high fuel loads which are produced annually by many grass weed species.
  • Rabbits are a threat to the single known population. While posing little threat to adult plants they may prevent recruitment by selectively grazing seedlings and young growth.
  • Borer and other insect damage has been observed on the branches of some plants, however, at this stage the threat this represents to the long term survival of the taxon is unknown.

Summary of population information and threats

Natural population
Pop. No. & Location Land Status Year/No. plants Condition Threats
1a. Whicher Range State Forest 1992 7
1996 7 (10)
1998 4 (17)
2000 3 (15)
2002 14
Moderate Dieback disease, inappropriate fire regimes, nearby mining activities, hydrological changes, weeds, rabbits, insect damage
1b. Whicher Range State Forest 2000 1
2002 0
Poor Dieback disease, inappropriate fire regimes, nearby mining activities, hydrological changes, weeds, rabbits, insect damage
1c. Whicher Range State Forest 2002 70 Moderate Dieback disease, inappropriate fire regimes, mining activities, hydrological changes, weeds, rabbits, insect damage
Translocated populations
Pop. No. & Location Land Status Year/No. plants Condition Threats
1T. Whicher Range State Forest 2000 (19)
2001 0
Poor Dieback disease, inappropriate fire regimes, weeds, rabbits
2T. Whicher Range State Forest 1998 (11)
1999 (4)
2000 (0)
Poor Dieback disease, inappropriate fire regimes, weeds, rabbits
3T. Whicher Range Nature Reserve 2000 (60)
2001
  Dieback disease, inappropriate fire regimes, weeds, rabbits
4T. Whicher Range Nature Reserve 2000 (140)
2001
  Dieback disease, inappropriate fire regimes, weeds, rabbits
Numbers in brackets = number of juveniles. T = translocated population.

Guide for decision-makers

Section 1 provides details of current and possible future threats. Any on-ground works (clearing, firebreaks, roadworks etc) in the immediate vicinity of Lambertia echinata subsp. occidentalis 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, or on the local surface hydrology such that drainage in the habitat of the species would be altered.