This past week I had the privilege of spending five early spring days at the National Seed Bank, based at the Australian National Botanic Gardens in Canberra. Incidentally (but most appropriately) coinciding with the start of National Biodiversity Month, the experience opened my eyes to the world behind the Gardens’ lawns and landscaping, and to the dedication and commitment of those working at the root of flora conservation.
The National Seed Bank holds both short and long-term collections for a range of native Australian species, the former primarily for supporting the living collections of the Gardens and the latter for conservation – seed banking can serve as a particularly valuable insurance policy against the threats species face in situ (and can also be considerably cheaper than on-ground conservation). Seed bank activities range from collection, cleaning and viability testing to banking, propagating and planned reintroduction.
The primary focus of my work throughout the week was assisting with a vigour assessment of the small purple-pea (Swainsona recta). This began with hands-on data collection – that is, counting and measuring the pea plants growing in 36 large concrete pipes in the Gardens’ seed production area.
With the measurements collated and entered into a spreadsheet, together with seed origin data from the Gardens’ Living Collection database, the next step was to determine whether a pattern of strong growth (or lack thereof) could be tied to certain seed collection locations. Such information could ideally then guide decisions as to which wild populations might benefit most from on-ground conservation efforts, and even which origin populations might provide the most viable seeds for propagation purposes. Although a clear determination could not be made at this stage, the methodology and baseline data will serve as a foundation for future investigation.
The small purple-pea
Once widespread across south-eastern Australia, the small purple-pea plant is now listed as endangered under the Commonwealth Environment Protection and Biodiversity Conservation Act, as well as across Victoria, NSW and the ACT. It is one of the 30 plants recognised in Australia’s Threatened Species Strategy and predominantly occurs in grassy woodlands, including the endangered White Box-Yellow Box-Blakely’s Red Gum Grassy Woodland ecological community.
The small purple-pea is threatened by habitat loss and degradation, and is particularly susceptible to grazing pressure. While maintenance of viable seed is a crucial component of this species’ conservation, consideration of remnant populations is also important. Indeed, for this very reason almost 300 Swainsona recta seedlings grown in the Botanic Gardens nursery are due to be translocated to the Wandiyali-Environa Wildlife Sanctuary, where only a few individual plants persist, just a week from the time of writing. But beyond such interventions, perhaps it is proactive protection of this species’ habitat that could have the greatest multi-scale conservation benefit, for individual pea plants and the ecological communities that grow naturally around them.