It came a surprise to me that all it took was an email to fling myself into the mysterious world of seed banking, even if just as a volunteer. Tucked away in the National Botanic Gardens, a cluster of modest brick and tin buildings make up the National Seed Bank. Tom North is the Seed Bank Manager whom led me through unfamiliar rooms dedicated to the various processes involved in seed preservation and research. Wide-eyed and a little overwhelmed I tried to familiarise myself with the different procedures involved.
Seeds go in, seeds come out?
The seed bank provides personalised homes for a variety of seeds, coming from different plants and places, and caters to their different purposes.
It’s helpful to understand that there are different reasons for preserving seeds. For instance, the ‘short term collection’ is comprised of seeds that will be distributed to the botanic gardens and supplied to particular organisations for research. ‘Long term collections’ are preserved for the conservation of native plants, as a valuable resource that may be used to revegetate an area or re-establish a threatened species in the future.
After the desired seeds have been collected, they are identified and cleaned. Seed quality and quantity is assessed in order to determine seed viability and their weight. Drying is the process that ‘ensures long-term seed viability’, and so the drying room is 15°C and 15% relative humidity. Following drying, the seed is sealed and numbered to correlate with the database. Cold storage involves deciding whether the seed collection is to be in short term or long-term storage. For short term, the seeds are stored back in the drying room. Long term storage collections require special attention in the Seed Bank freezers, where they need to have 3-7% moisture content, and the freezers are set to -21°C. There are still some uncertainties surrounding how long some species are able to remain ‘alive’ in these preserved environments. Thus, seed viability in storage is monitored by germination trials, and longevity is also tested to support apt replacement schemes (read more at https://www.anbg.gov.au/gardens/living/seedbank/seedprocedures.html).
The biology and ecology of Australia’s natives’ seeds are a focus in the research side of things. My role at the seed bank involved a repetitive but important step in preparing native seed for ecological research…
I was assigned the task of counting and weighing a collection of Pomaderris species, the main one of interest being Pomaderris cotoneaster. Pomaderris is a genus consisting of 70 species of shrub to small tree. A large number (65) of these species are native to Australia. P. cotoneaster is considered endangered by both NSW and the Commonwealth (for further information on this species’ distribution, habitat, threats and recovery strategies see http://www.environment.nsw.gov.au/threatenedSpeciesApp/profile.aspx?id=10648). Research being undertaken by the University of Wollongong (UoW) on Pomaderris involves the ecology of the species and germination capabilities. Not much is known about the ecology of P. cotoneaster, or the reasoning behind its current distribution. And so, the UoW requested the Seed Bank for a certain amount of seeds from each species within their collection. These seeds had been collected from areas of the species current and natural extent.
The Pomaderris seeds were retrieved from the Seed Banks’ drying room, where most of them have been kept since December last year (2016) to ensure seed viability. They had already been cleaned, counted and packed. Pomaderris seeds are quite tiny; it would be an absolute nightmare attempting to count and separate 100 seeds from a pack of thousands. This is where the trusty ‘seed counter’ comes in to minimise the tedious nature of counting seeds (see below).
‘The Friends of the Australian Botanic Gardens’ kindly funded the purchase of this machine. The user simply selects the desired seed count to retrieve, places the seeds into the top of the counter and waits as the machine uses vibration to channel seeds one by one down a channel. As the seeds drop a light sensor counts them, once the count gets close to the desired amount the counter stops vibrating, whilst allowing time for the remainder seeds to fall. The outcome is usually spot on, although sometimes a few more seeds are counted and dropped into the collection draw. If this happens the additional seeds are simply removed.
1000 seed weight counts are an important chore in the upkeep of the collection. This involves deriving an average weight for the seeds of each species throughout their time spent in the Seed Bank, to identify any changes that may suggest a loss of seed viability. I undertook 1000 seed weight counts for the Pomaderris species being distributed to UoW and within the Seed Banks collection.
Saving (and researching) for the future
Seed banks are delightfully described as ‘living libraries that help researchers fund solutions to the worlds disease, pest, and climate problems’. The National Seed Bank supports a variety of projects that do just that. The Seed Bank is a member of the Australian Seed Bank Partnership (ASBP). The ASBP aims to collect, bank and research the seeds of Australia’s natives in a national effort to conserve its diversity. During my volunteer experience, I learnt of the Seed Banks’ important role in conserving biodiversity in the most literal sense. The facility itself is dynamic, providing vital resources to researchers and organisations across Australia. It assists with research that fortifies the preservation of native seeds in light of climate change adaption. The fundamental purposes of the Seed Bank are to:
- Avoid the complete loss of threatened Australian species
- Support biological understanding of species to enhance future adaptions (genetically assisting certain species or broadening knowledge of possible future habitats)
- Provide seed for current regeneration projects
- Conserve Australia’s unique biological identity
As we continue into a time where the threats to and loss of biodiversity seem to only increase, efforts to conserve and research persisting species couldn’t be more crucial. Understanding their phenology through germination trials and seed biology research is beginning to prove its importance in today’s efforts of biodiversity conservation.
 Australia. NSW. Office of Environment and Heritage. Cotoneaster Pomaderris. http://www.environment.nsw.gov.au/threatenedSpeciesApp/profile.aspx?id=10648
 Locke, Sarina. ‘Seed Banks: The living libraries that hold answers to disease, pest and climate problems’ ABC Rural. 28th March 2016