Small Purple Pea (Swainsona recta)
The Small Purple Pea (Swainsona recta) was declared an endangered species in the ACT in April 1996 and has special protection status. It is also listed as endangered in NSW and threatened in Victoria.
This slender, erect perennial plant produces several stems that are 20–30cm high and has a taproot that can extend at least 60cm below the soil surface. A perennial forb, it persists as woody rootstock throughout late summer and autumn then re-sprouts between April and August and flowers during spring. The likelihood an individual plant will flower is linked to the number of frost nights in the preceding year, with a plant most likely to flower when there are between 7 and 15 nights equal to or less than -4oC. Also, fire is believed to facilitate re-sprouting and stimulate seed germination.
In the past, the Small Purple Pea was relatively widespread in north-eastern Victoria and the South and Central Western Slopes and Tablelands of NSW, but over the past 80 years the range has declined considerably. Its population is now fragmented into two clusters, one in central eastern NSW (between Wellington and Mudgee) and the other in the Canberra–Williamsdale district.
More than 400 individual plants have been recorded at Mt Taylor since monitoring began at the site ten years ago under the previous action plan. While only a few new plants establish each year, the population at Mt Taylor is considered stable. Other populations exist at Kambah and south-east Belconnen.
In 2012 and 2013, 112 plants raised at the Australian National Botanic Gardens were translocated to three plots near the Gigerline Nature Reserve in the south of the ACT, with around a third of them surviving.
Conservation threats
Urban development and agricultural practices have resulted in the loss, degradation and fragmentation of the Small Purple Pea’s woodland habitat. As a result, populations of the species in the ACT are small, severely fragmented and vulnerable to extinction.
Small populations are also subject to inbreeding and reduced genetic diversity. This reduces germination success and fitness within populations, and leaves them vulnerable to the impacts of disease, climate change and disturbance. Invasive plants, inappropriate fire regimes, and browsing by native and feral herbivores places additional pressure on the survival of this species.
A range of indirect impacts resulting from a changing climate may threaten the species’ survival at some sites, including increased drought conditions, changes in plant species composition (including invasive species), and fire frequency and intensity.
Conservation objectives
- Protect sites where the species is known to occur in the ACT from unintended impacts.
- Manage the species and its habitat to maintain the potential for evolutionary development in the wild.
- Improve the long-term viability of populations through management of adjacent woodland to increase habitat area.
- Expand the range of the species in the ACT by identifying suitable habitat and establishing new populations by translocation.
- Improve the understanding of the species’ ecology, habitat and threats.
- Strengthen stakeholder and community collaboration in the conservation of the species.
Conservation actions
The Small Purple Pea’s populations across the ACT are at high risk of local extinction. The management priorities for the species is to maintain and enhance site condition. Conservation actions include:
- protect populations from unintended impacts
- require site management to conserve the species and its habitat
- monitor populations and the effects of management actions
- undertake genetic rescue on targeted small populations
- annual monitoring of all known sites, including habitat assessments
- manage grassland and woodland adjacent to the species’ habitat to increase habitat area or connectivity
- facilitate research and trials to increase population size and establish new populations
- facilitate research on habitat requirements, techniques to manage habitat, and aspects of ecology relevant to the conservation of the species
- promote greater awareness and strengthen stakeholder and community engagement in the conservation of the species.
More information
Contact
Email environment@act.gov.au or phone Access Canberra on 13 22 81.