Nicola Arndt und Matthias Pohl - Neobiota

to the FAO GEZ is straightforward. In other cases, a more thorough study of mapping criteria,
including physiognomy, phenology, floristics and dynamics of vegetation types, was needed to
establish the correspondence. An additional benefit of using the existing country/regional maps is that
they could form the basis or provide supporting information for more detailed regional ecological
zoning beyond FRA 2000.
The country/regional vegetation maps also helped in harmonisation of Ecological Zone boundaries
across countries or regions. The experts attending the Cambridge expert consultation contributed in a
major way to define Ecological Zones of their respective regions as well as in edge matching between
adjoining geographic regions.
The following steps were applied to define and map the FAO global Ecological Zones region by
region. They are divided in conceptual, thematic issues and technical production steps.
4.2 Conceptual and thematic issues
Collection and study of relevant maps and information: suitable regional/national maps of climate,
potential natural vegetation or ecoregions were searched and studied. The ideal maps show distribution
and zonation of (potential) natural vegetation, and have supporting documentation with details on
classification system and criteria. Other important (map) attributes are floristic and phytogeographic
information, climate and landform or physiography. Depending on regions, the scale of maps was
usually smaller than 1 million, and both paper and digital versions of the maps were obtained. A first
step in the selection of source maps was to identify and delineate the Köppen-Trewartha climate types
occurring in the country or region which are the approximate boundaries of FAO GEZ Level 2. This
was followed by an in-depth study of the ecological criteria used – and/or vegetation maps, focusing
on classification principles –, to select the input maps for generating the global EZ map. Consultation
with regional experts, i.e. authors of maps and publications, was vital in this process. A reference list
was made of all source data used (see Annex Table 4).
Matching or aggregating national/regional classes into the FAO GEZ: Based on the in-depth study
the relation between national/regional source classes, vegetation types, ecoregions etc., and the Level 2
global Ecological Zones was established. This usually involved aggregation of a number of regional
classes into one GEZ. Then an “equivalence“ or look-up table (LUT) for the region was produced,
showing the correspondence between the regional classes and the global Ecological Zones Level 1 and
2 (see Table 2), together with documentation and explanation of the matching for review and
evaluation purposes. This includes the description and definition of the regional vegetation types or
ecosystems.
4.3 Map production and technical Issues
Both the existing FRA1990 ecofloristic zone maps and several existing regional maps have been
produced using ESRI Arc/Info GIS software system. Thus, it was convenient for the rest of the work
to be conducted on Arc/Info, or at least Arc/Info importable. After study of the digital map in the
Arc/Info coverage environment and making sure the digital version has appropriate attributes for the
polygons, the coverage was edited and attributes for each FAO GEZ levels (1 and 2) were added.
Regarding polygon edge-matching problems along country and regional boundaries, two related
causes occurred. One was due to mismatch of polygon definition translations between polygons of
both sides, as stated earlier. This problem was generally easy to solve by going back to the original
maps and making sure the translation being correct.
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