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The Global Seed Conservation Challenge: Can botanic gardens achieve GSPC Target 8 by 2020?

Volume 12 Number 1 - January 2015

Katherine O’Donnell and Suzanne Sharrock

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Introduction

It has recently been reported that only 29% of plant species on the IUCN Red List of Threatened SpeciesTM are in ex situ collections (Sharrock et al., 2014). Target 8 of the GSPC calls for ‘at least 75 per cent of threatened plant species in ex situ collections, preferably in the country of origin, and at least 20 per cent available for recovery and restoration programmes’ by 2020.

With less than 6% of the estimated 400,000 species of plants formally assessed at the global level using IUCN criteria, monitoring progress of ex situ conservation is difficult. However it is clear that more needs to be done if this GSPC target is to be realised.

Seed banking

Orthodox seeds can be collected from plants, dried and stored in cool conditions until they are required for research, restoration or reintroduction. Seed banking is increasingly being used as a method of ex situ conservation for a variety of reasons:

  •     It is the most cost effective method of ex situ conservation;
  •     A higher genetic diversity can be sampled when collecting than for living collections;
  •     Seeds take up less room than living plant collections;
  •     Seeds can survive for hundreds of years in conditions of low humidity and low temperature.

Botanic garden seed banks: the current situation

In order to identify the gaps in seed banking it is essential to determine the baseline situation. BGCI in conjunction with the Millennium Seed Bank Partnership has therefore recently carried out a global review of the role of botanic gardens in seed conservation.

This review was based on information from BGCI’s GardenSearch and PlantSearch databases along with data on MSBP partners and the results from a recent BGCI survey on seed banking in botanic gardens.

The survey was sent to GardenSearch contributors in over 700 institutions. 271 individual institutions responded from 65 countries. The questions in the survey aimed to determine:

  •     Which institutions are involved in seed collecting and banking;
  •     What protocols are being used for collecting and banking;
  •     Seed storage facilities and conditions available in botanic gardens;
  •     Institutional reasons for seed conservation;
  •     The limitations preventing gardens becoming involved in or doing more seed conservation;
  •     Data management of accessions and use of PlantSearch to share data.

Seed survey results

Seed collecting

Nearly 80% of the institutions that responded to the survey collect seed as part of their work. The main reasons for collecting seed include conservation and back up/replacement of the living collections. There is a strong emphasis on collecting seed of threatened or endemic taxa within these gardens.

A number of gardens (74) that collect seed do not presently bank this seed. This is due to several factors, including lack of trained and available staff, lack of infrastructure, insufficient funding and lack of institutional priority. Of these institutions more than 80% would be interested in banking the seed they collect.  This includes institutions in nine countries where there are currently no botanic gardens involved in seed banking.

Seed banking: the global overview

It is recognised that many institutions in a wide range of countries collect and bank seed.  However in many cases, seed banking focuses on agricultural crops and falls within the remit of agricultural institutes and agencies.  The focus of our survey was to identify institutions involved in seed banking of wild plants, and particularly threatened species, which are generally not included in agricultural seed banks.

The results of the survey allowed us to identify over 50 institutions involved in such seed banking on which we previously had no data.  In order to determine a global overview, this information was combined with that of MSBP project partners and information from GardenSearch.

The analysis revealed that at least 421 institutions are involved in seed banking of wild plants in 97 countries. Botanic gardens are the main institutions involved in such seed banking, however a variety of different types of institution were also identified, including arboreta, universities, natural history museums, forestry and tree seed centres, science institutes and even zoos.

As expected, the number of seed banks per country is not even. Several countries including the United States, Australia, and France have more than 20 institutions involved in seed conservation. However, for the majority of countries, we have so far identified only 1 or 2 institutions involved in seed banking for wild plants.

Our seed banking work just beginning, there are lots of things needed to prepare and learn. It's a good chance for us to get in touch with the project Global Seed Conservation Challenge. We are looking forward to donating our enthusiasm and endeavour to this wonderful project”. Binjie Ge, Shanghai Chenshan Botanical Garden, China

Information on countries where few or no wild plant seed banks exist was analysed against patterns of plant diversity to determine gaps in seed banking. Central Africa, South America and South East Asia were highlighted as the main regions with high plant diversity but limited seed banking activity.

The survey also revealed that the majority of institutions involved in seed conservation, bank seed at their own institutions. Those that don’t have their own institutional facilities are either involved in the Millennium Seed Bank Partnership and store seed at the MSB seed bank in the UK or bank their seed at another institution in-country.

Number of species conserved.

BGCI’s PlantSearch database acts as an essential tool for monitoring progress towards Target 8 of the GSPC. Gardens are able to upload their living plant, seed and tissue collection data to this global database.

Of the survey respondents that collect and bank seed, the majority do not upload their seed accession data to PlantSearch. Those that do mostly upload their seed accession data under a different institutional profile to that of the ‘parent’ botanic garden. This is then listed as institution type ‘Gene/Seedbank’ and the accession data can be distinguished from that of living plant collections.

Using PlantSearch data, we are only able to identify 37,937 distinct taxa in seed banks around the world. The majority of these are from the MSBP which has approximately 34,000 taxa in its seed bank.  However, recipients of the survey were asked how many wild collected species/taxa their seed banks held. Analysis of this data suggests that at least a further 17,000 taxa are being banked by botanic gardens around the world. For MSBP data the country of origin of the collections is known. For additional collections highlighted by the survey, it was assumed that the seed banking country was the country of origin. This data was analysed at the country level to show the number of banked taxa globally.  There are several countries where we are not aware of any seed collections of wild plant species. A high number of species have been banked in the United Kingdom, United States, Australia, China, South Africa and France.

Seed banking standards

The protocols used for collecting and banking seed are important in order to ensure high quality seed of conservation value. When conserving seed it is essential to aim for high genetic diversity and maximum viability. 

Seeds should be collected from a large number of individuals within a population in order to capture the most genetic diversity. In order for seed to have a high viability, efforts must be made at the time of collection to gather mature and viable seed.

There are a variety of protocols used by institutions involved in seed conservation including those developed by the MSBP, ENSCONET (European Native Seed Conservation Network) and the Seeds of Success.  The majority of institutions however collect and bank seed using their own institutional protocols.

Drying seed increases its longevity and is essential for long term storage. For every 1% decrease in moisture content the life of a seed is doubled (Harrington, 1963).  Based on the results of the survey, 65% of the institutions that collect and bank seeds have drying facilities which range from the use of desiccants such as silica gel to more costly incubator driers and drying rooms. 26% don’t have any drying facilities and 9% did not respond. Nearly all of the institutions that do have drying facilities bank for the medium (1 to 5 years) or long-term (more than 5 years).

Long term storage is an issue, given the specifications needed for adequate humidity and temperature control.” The Arthur Ross Greenhouse at Barnard College / Columbia University.

Once dried, seed should be placed in hermetically sealed containers in order to keep moisture out. The most efficient containers are trilaminate foil which can be heat sealed and glass jars with air tight lids (Gold and Manger, 2014). Paper packets were found to be the most commonly used containers that seed collections were stored in. 

Correctly identifying seed collections is essential if the seeds are to be utilised. Voucher material such as herbarium specimens should be collected at the time of seed collection in order to accurately identify seeds to a particular species. A third of the respondent institutions do not use voucher specimens to verify collection names.

It is advisable to store a duplicate accession of banked seed at another institution as an insurance against loss. Nearly two thirds of the institutions that answered this question do duplicate their collections. 

Networking

Only half of the survey respondents reported being part of a seed banking network (57%). These included international networks such as the MSBP; regional networks such as ENSCONET and national networks, such as the French Conservatoires Botaniques Nationaux the Center for Plant Conservation (US) and the Red Argentina de Bancos de Germoplasma de Especies Vegetales Nativas (Argentina). Of the institutions that are not part of a seed banking network, 90% agreed that they would benefit from being involved in one.

We'd love to help, but don't have the resources to be that helpful. Many regional botanic gardens are not equipped to be part of this worthy initiative. We'd be happy to facilitate your organisation in collecting seed from around Bendigo though. “ Brad Crème, Bendigo Botanic Gardens, Australia.

Objectives and limitations

The main objectives for survey respondents to collect and bank seed are generally the same. Most collect and bank seed for conservation and as a backup or to replace living collections.  Reintroduction and exchange (index seminum) are also important. Several institutions collect and bank seed for research purposes.

For institutions that are already banking seed there are several limitations to increasing this activity. These include factors such as infrastructure, human resources and funding. Lack of institutional priority was generally less of a limitation.

“One limitation is national and international support. We need BGCI and MSBP to help us with advocacy’ Tom Myers, Dunedin Botanic Garden, New Zealand.

Botanic gardens that collect and bank seed prioritise endemic and threatened species which are not trees. There is less emphasis on conserving trees and economically important taxa. This is not surprising as tree species usually require specialist equipment for seed collection.

We focus on rare genotypes or disjunct populations and range extremes” Ethan Kauffman, Moore Farms Botanical Garden, United States

Discussion

Through the survey, we have identified a number of institutions involved in seed banking that were not previously documented in BGCI’s databases. In order to be able to accurately monitor and measure the botanic garden community’s extensive contribution to Target 8 of the GSPC, ex situ seed collections must be well reported. 

The results of the survey suggest that at least a further 17,000 taxa are being conserved as seed in botanic gardens around the world than we were previously aware of. We cannot currently determine whether or not these accessions are unique taxa as information is not available in BGCI’s databases.
Incorporating this data into PlantSearch would be the first step to determining which threatened and orthodox species are not in ex situ seed collections. Currently only a limited number of institutions that are involved in seed banking upload their seed accession data to PlantSearch. By uploading seed accession data, progress can be reported and priorities set.

Documentation is important not just for monitoring progress against targets but it is also essential for ensuring ex situ collections are available for research, reintroduction and restoration.
If seed collections are to be of conservation value, the protocols used for banking must be of a high standard. The survey indicates that some gardens could benefit from implementing higher standards for post-harvest seed handling in order to ensure that the viability of their seed is maintained. Drying and storing seed in air tight containers is important as damp seed quickly loses viability. Furthermore, if seed accessions are not verified with a herbarium voucher, their use for reintroduction, restoration and research is limited. Duplication of accessions is also important for safeguarding the collections.  

Finally, we can say that through the survey, we have identified a number of strengths and a number of weaknesses in relation to seed banking in botanic gardens.  Our aim now is to build on the strengths and address the weaknesses as we engage the whole community in the Global Seed Conservation Challenge.

References

Gold, K. and Manger, K. 2014 RBG Kew Technical Information Sheet_06: Selecting containers for long-term seed storage [online] www.bgci.org/seedconservation/hub

Sharrock, S., Oldfield, S. and Wilson, O. 2014 Plant Conservation Report 2014: a review of
progress in implementation of the Global Strategy for Plant Conservation 2011–2020. Secretariat of the Convention on Biological Diversity, Montréal, Canada and Botanic Gardens Conservation International, Richmond, UK. Technical Series No. 81, 56 pages.

Harrington, J.F. 1963. Practical advice and instructions on seed storage, Proc. Int. Seed Test. Assn., 28: 989-994.