Novel threat assessment of priority CWR

Why is threat assessment important in CWR conservation planning?

CWR, like any other wild plant species, are increasingly subject to anthropogenic threats. As a result, they experience genetic erosion and are increasingly at risk of extinction. Moreover, these threats have a direct economic and social impact on humankind; if the genetic diversity within CWR is unavailable for exploitation, food insecurity is then a threat to humankind itself. Assessing the risk of extinction of CWR taxa is therefore an important stage in conservation planning. This will help to identify the taxa in greatest need of immediate conservation action, it will improve our understanding of the specific conservation requirements of CWR and will establish a baseline for monitoring their threat status over time.

Novel threat assessment is particularly important for those CWR that have not yet been assessed at all and for those with outdated assessments. For the remaining taxa, existing threat assessments may already have been collated at the CWR prioritization step. Nevertheless, it should be highlighted that sufficient resources are rarely available to undertake novel threat assessment of all the CWR in a checklist. CWR conservation planning requires the collation of large and complex datasets that enables the implementation of conservation actions, and these datasets may also be used in the threat assessment process. Novel threat assessment can then be undertaken in parallel to conservation planning and implementation, and can be used to further prioritize/enhance CWR conservation.

The assessment of threats facing CWR diversity can be carried out at two levels: (1) the individual taxon level (commonly species but also at infra-specific level) and (2) the genetic level:

  1. Assessing the threat status of individual taxa can inform CWR species prioritization for conservation―the most threatened species having higher conservation priority. Further, threats to a specific region may be assessed to aid conservation planning (i.e. to identify areas with high numbers of threatened CWR). However, in this case, it would require the completion of a large number of individual species assessments and a comparison of the threats in different regions.
  2. At the genetic level, the threats of genetic erosion and pollution to CWR should be examined and understood as they can eventually lead to population—or even taxon— extinction. A decrease in genetic diversity results in the loss of genes and alleles that then will not be available for future exploitation for crop improvement. This will ultimately have a negative impact on future food security. Additionally, the loss of genetic diversity implies a reduced capacity for taxa to adapt to the rapid changes in environmental conditions the planet is experiencing, and therefore a lack of availability of particular adaptive elements in crop gene pools for the development of new crop varieties able to withstand these new conditions.

The IUCN Red List Categories and Criteria (IUCN 2012a) have been widely used for assessing species extinction risk (or threat status). They were developed to improve objectivity and transparency in the threat assessment process, and therefore to improve consistency and understanding among users. These categories and criteria can be used to assess the risk of extinction of a species at the global level.

However, when the threat status of a species is being assessed at national (or regional) level—as in the context of a National Strategic Action Plan for the conservation of CWR—then the regional criteria, Guidelines for Application of IUCN Red List Criteria at Regional Levels (IUCN 2012b), should be used to determine the appropriate Red List category for a taxon. This is particularly relevant for species that also occur outside of the target region1 of the study, as wild populations are not delimited by national boundaries. When the distribution of a particular species goes beyond the limits of a geopolitical border, there might be genetic flow to or from other conspecific populations beyond that border that will affect the stability, and therefore the extinction risk, of the species. For example, a taxon classified as Least Concern globally might be Critically Endangered within a particular region where numbers are very small or declining. Conversely, a taxon classified as Vulnerable on the basis of a global decline in numbers or range might be Least Concern within a particular region where its population is stable (IUCN 2012a). As a result, the Guidelines for Application of IUCN Red List Criteria at Regional Levels (IUCN 2012b) were developed to re-assess the risk of extinction of species in a particular region within the light of its overall distribution. However, when the regional population is isolated from conspecific populations, global criteria can be used without modification.

1 ‘Region’ is defined by the IUCN (2003) as any sub-global geographically defined area (e.g. continent, country or province).

The Interactive Toolkit for Crop Wild Relative Conservation Planning was developed within the framework of the SADC CWR project (2014-2016),
which was co-funded by the European Union and implemented through ACP-EU Co-operation Programme in Science and Technology (S&T II) by the African, Caribbean and Pacific (ACP) Group of States.
Grant agreement no FED/2013/330-210.