GSPC Target 8

Introduction

Ex situ plant conservation is defined as the conservation of plant diversity outside its natural habitat.

Ex situ conservation plays a complementary role to in situ conservation, providing a 'safety back-up' and an insurance policy against extinction in the wild.

While in the past, more emphasis was placed on in situ conservation as the primary means of conservation; ex situ conservation, in the form of seed banks, in vitro collections, field genebanks and the living collections of botanic gardens, has proliferated in recent years.

Given the fact that ecosystems are already rapidly and demonstrably shifting as individual species react differently to climate change, ex situ conservation is assuming a new and important role in conservation strategies. 

Quoting from BGCI's publication: Plants and climate change: which future?  - "In the face of an uncertain future, an urgent priority must be given to conservation through seed-banking and living collections for as many plant species as possible, by way of an insurance policy".

Botanic gardens are the main institutions involved in the ex situ conservation of wild plant diversity. The number of botanic gardens in existence around the world has more than doubled in recent years and their combined plant collections consist of more than 100,000 species, nearly one third of all known plants, including many threatened species. Many botanic gardens are involved in the implementation of this target, with organisations such as the Millennium Seed Bank of the Royal Botanic Gardens, Kew, playing a key role.

A review of the role of botanic gardens in the implementation of this Target can be downloaded here.

Download an introduction to Target 8 here.

Learn more

The focus for this target is to ensure that genetically representative collections of the most critically threatened species are developed. The collections should be accessible, backed-up and preferably in the country of origin. There is also a need to ensure that material is available for use in restoration and recovery programmes to ensure that the second part of the target is met.

There are various forms of ex situ conservation:

Seed conservation

Seed conservation is useful for plants with 'normal' seeds that can be dried and stored at low temperatures for long periods. This is the most cost efficient and common form of ex situ conservation. A large number of seeds can be stored in a small space and good sampling techniques will ensure that the genetic diversity of any given plant population is represented in the seed sample.

In vitro conservation

In vitro conservation includes plant tissue culture and cryopreservation. In these types of conservation, small parts of the plant (typically growing points or meristems) are removed from the plant and conserved in artificial media in sterile conditions at low temperatures (very low in the case of cryopreservation). These techniques are useful for plants whose seeds are 'recalcitrant' or cannot be dried and stored at low temperatures (as is the case for many tropical tree species). In vitro techniques are more expensive than seed conservation and require a higher level of skills to implement. However, they also allow large number of plants to be stored in a small space.

Field genebanks

Field genebanks are more commonly used for maintaining the genetic diversity of agricultural crops that cannot be stored as seeds (see Target 9). They are less common for the conservation of wild plant species.

Living collections of botanic gardens 

The living collections of botanic gardens include a large number of threatened wild plant species. However, while the number of species represented in such collections is high, the genetic diversity that is present in the wild populations of these species is often not well represented in botanic garden collections. Nevertheless, species held in well-documented, genetically representative living collections are valuable for ex situ conservation as well as having additional value, in that they provide material for:

• Horticulture and field-based research (propagation methods, growth requirements etc).  

• Propagation of plants to remove or reduce pressure from wild harvesting.

• Taxonomic and systematic research and reference for identification.

• Display, education and community engagement activities.

• Species reintroduction and habitat restoration activities.

• Identification of taxa for introduction into the nursery trade, local agriculture and crop breeding programmes, amenity planting, local forestry etc.

Recovery and Restoration

The second part of Target 8 focuses on the use of ex situ collections to support species recovery and ecosystem restoration initiatives. Further information on the implementation of such projects is available here.

Linkages

The implementation of this target contributes to Targets 12 and 15 of the Aichi targets of the Strategic Plan for Biodiversity 2011-2020:

T12: By 2020, the extinction of known threatened species has been prevented and their conservation status, particularly of those most in decline, has been improved and sustained.

T15: By 2020, ecosystem resilience and the contribution of biodiversity to carbon stocks has been enhanced, through conservation and restoration, including restoration of at least 15 per cent of degraded ecosystems, thereby contributing to climate change mitigation and adaptation and to combating desertification.

Implementation

A number of guidelines, manuals, case studies and on-line resources are available to support implementation of this target.

The target consists of two main areas of activity. Ex situ conservation of threatened species and the use of conserved materials to support species reintroduction programmes and the restoration of damaged habitats.

Further information on the implementation of ex situ conservation is available here.

Further information on the implementation of recovery and restoration programmes is available here.

Tools and resources

Please also check in the database of Tools of Resources for Case Studies relevant to this target.



Status

BGCI has been monitoring progress towards this target using its PlantSearch database. PlantSearch is a database of plants in cultivation in botanic gardens around the world, linked to IUCN Red Lists and other relevant information. It presently includes records for over 100,000 species in cultivation in over 800 gardens and arboreta around the world.

An analysis of the database has revealed that around 9,000 globally threatened plant species are in cultivation in botanic gardens. This is a long way short of the 75% target, but monitoring progress is constrained by the lack of progress in Red Listing at the global level.

A report on the global progress towards Target 8 can be downloaded here.

Regional reviews of progress have also been carried out by BGCI.

In Europe, 42% of 1,917 regionally threatened plants have been identified in European living collections and seedbanks, while in North America, collections hold 39% of 9,496 regionally threatened taxa.

Download the report on progress towards Target 8 in Europe here.

Download the report on progress towards Target 8 in North America here.

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