CWR In Situ Strategy Helpdesk

Crop gene pool methodology

Step 3: Ecogeographic diversity analysis

Background

Once the priority list of CWR species has been identified (Step 2), the next step is to collate the available ecogeographic information to assist in further formulation of the CWR conservation strategy.  This involves the collation and analysis of geographic, ecological, environmental and genetic data.  These data are predictive and aid the location of the CWR taxonomic (inter-taxa) and genetic (intra-taxon) diversity that can then be targeted for conservation.  The culmination of the ecogeographic diversity analysis should be a set of areas with high concentrations of the priority CWR species and populations of CWR taxa containing or thought to contain complementary and / or unique genetic diversity.

At regional or global level, it is not expected that genetic data will be available for populations throughout the range of a target CWR, except for taxa that have already been the subject of detailed investigation.  Therefore, when selecting target sites for CWR genetic reserves at regional (e.g., across Europe) or global level (see Step 4), it will be necessary to use the available geographic and ecological data to make reasoned assumptions about the most appropriate sites.

In some cases, the range of the target taxon will define the precise site or sites where active in situ conservation is needed. Obviously, a taxon that is known only to occur at one location and is considered a high priority as a potential gene donor, then that single location must be targeted for reserve establishment.  Where the geographic range of the target taxon is broader, sites should be selected that represent the widest range of ecogeographic characteristics as possible.

Step 3 actions – carry out an ecogeographic diversity analysis

At this stage, the aim is to collate all available ecogeographic data associated with the target taxa.  Assuming the taxonomic data has already been collated in Step 1, the remaining data are of three main types:

  • Geographic
  • Ecological / environmental
  • Genetic

As mentioned already, it is not expected that genetic data will be available for regional (e.g., European) or global level conservation planning, except in a minority of cases.

  1. Gather geographic (distribution) data on the target taxa.  Data are of two types—coordinate and descriptive.  Ideally, coordinate data should be used for accuracy (however, even coordinate data can sometimes be misleading, depending on the accuracy and quality of the original data).  Descriptive data can be converted to coordinate data by consulting gazetteers.  A good starting point for the collation of geographic data is GBIF.  Data downloaded from GBIF can then be supplemented by consulting a range of other data sources, such as EUNIS (for Europe) and national or specialist taxonomic databases.   Consult the data sources page for further information on collating distribution data. At this stage in the analysis, issues of data quality have to be taken into account and steps may need to be taken to improve the accuracy of the distribution data to remove any erroneous entries. For example, it has been suggested that only population occurrences with geographic coordinates that have two decimal digits or more are used in the analysis. Another limitation is that the availability of occurrence data may be very heterogeneous across the range of the target taxon—this needs to be taken into account when making decisions on the selection of target sites (Step 4). Where distribution data are too sketchy or otherwise incomplete or inaccurate, it may be necessary to recommend that a detailed ecogeographic survey is undertaken before further analysis.
  2. Gather ecological and environmental data on the target taxa.  Ecological and environmental data associated with the target taxa can be of two types: actual (i.e., data directly linked to a taxon) or predictive (i.e., data indirectly linked to a taxon via the attributes of the site in which it is found).  Actual ecological and environmental data can be sourced by obtaining characterization and evaluation data associated with ex situ accessions, and/or by consulting the available literature on the target taxon—for example, there may be published or grey literature as a result of ecological studies of the taxon or of associated taxa that occur in the same habitats—or by collecting fresh data in the field.  Predictive data are obtained by gathering data associated with known locations of a taxon (e.g., climate, soil type, geological substrate, habitat type, altitudinal range and land use).  Some of these data are readily available in the form of Geographical Information System (GIS) files, which are overlaid with the distribution data, and from which inferences can be made about the ecological preferences of a taxon.  Consult the data sources page for further information on gathering ecological and environmental data.
  3. Gather genetic data on the target taxa.  This part of the analysis is only possible where genetic diversity information already exists or where resources permit the generation of novel genetic diversity information.  There are two types of genetic diversity information of interest for the establishment of genetic reserves and for backup in ex situ collections: intra-population and inter-population diversity.  The precise method of generating genetic diversity information is taxon-specific.  Decisions regarding the type of genetic analysis to undertake can be based on existing studies of related taxa or taxa sharing similar biological attributes.  Literature searches can be undertaken to obtain this information, as well as consulting specialist databases and taxon experts.
  4. Analyse the ecogeographic data.  The data collated is now analysed to build detailed taxon ecogeographic profiles.  GIS programs such as ArcGIS or DIVA GIS can be used to create distribution maps overlaid with ecological, environmental and genetic data, and locate complementary genetic reserve locations.  The data should also be imported into an appropriate information management system from which standard taxon data sheets can be extracted to form the basis of genetic reserve proposals and management plans.

Crop gene pool methodology introduction > Step 1 > Step 2 > Step 3 > Step 4

Helpdesk references

Map, courtesy of © M. C. Duarte, Instituto de Investigação Científica Tropical, Lisboa, Portugal