CWR In Situ Strategy Helpdesk

National CWR flora methodology

Step 3: Ecogeographic and genetic diversity analysis of priority CWR

Once the priority list of CWR taxa is identified, there is a need to collate the ecogeographic and genetic diversity information that is available to assist in further formulation of the CWR conservation strategy. This involves the collation and analysis of all available ecological, geographic, genetic and taxonomic data, which are obtained from the literature, passport data associated with herbarium specimens and germplasm accessions, and possibly from novel studies as well. These data are ecologically and geographically predictive because they aid the location of the CWR taxonomic (inter-taxa) and genetic (intra-taxon) diversity that can then be targeted for either in situ or ex situ conservation. In terms of in situ conservation, the culmination of the ecogeographic and genetic diversity analysis should be a set of areas with high concentrations of the priority CWR species, possibly identified using GIS analysis of ecological, geographic, genetic and taxonomic data. These areas might be considered analogous to the broader taxonomic Important Plant Areas for all plant species (Target 5 of the CBD Global Strategy for Plant Conservation – CBD, 2002) and could be referred to as Important CWR Areas. In terms of ex situ conservation, the culmination of the ecogeographic and genetic diversity analysis will be populations of CWR taxa containing or thought to contain unique genetic diversity that is not already conserved ex situ, and once identified, this material may be collected and conserved in the appropriate gene banks. In this context it is important to note that while accessions of CWR taxa may be held in ex situ collections, this does not necessarily mean that they are genetically representative samples and so the assessment should involve a comparison of the full range of the taxon with the range of that proportion of the taxon’s genetic diversity sampled and held ex situ—a single accession in a genebank does not mean the taxon’s genetic diversity is effectively conserved ex situ.

The UK flora is one of the most well studied floras of the world with records stretching back hundreds of years and being constantly updated—the New Atlas of the British and Irish Flora (Preston et al., 2002a) uses this resource to provide distribution records for all wild plant taxa as occurrence in 10x10 km squares of the UK Ordnance Survey National Grid. These occurrence records can be analysed using regression analysis to indicate change and significance of change over time (Preston et al., 2002b; Telfer et al., 2002). As an example of the kind of analysis that is possible of the UK CWR taxa with known distributions, more than 40% are common to very common, as they occur in >50–25% of UK hectads, while an additional 26% can be considered near-scarce as they occur in <25% but more than 100 grid squares, and more than a third of the taxa with known distributions are scarce to very rare.

Step 4: Identification of threats to priority CWR taxa and important CWR areas

Helpdesk references