WWF Shining a spotlight on the biodiversity of ... - MarineNZ.org.nz

Appendix 1
<strong>WWF</strong>
Methodology
for selection
of the
Global 200
ecoregions
Ecoregions were derived using a hierarchical
methodology in which biodiversity was
stratified by the terrestrial, freshwater, and
marine realms, major habitat types, and
biogeography. In the terrestrial realm 14
major habitat types were identified, such as
mangroves, flooded grasslands and savannas,
temperate coniferous forests, and tundra.
Among the seven major freshwater habitats
types are large rivers, small lakes, and xeric
basins. The marine realm includes a total of
nine major habitats types: polar, temperate
shelf and seas, temperate upwelling, tropical
upwelling, tropical coral, pelagic trades,
pelagic westerlies, abyssal, and hadal (Olson
et al. 2000). 13
In order to represent the unique biota on
different continents or ocean basins each
major habitat type was further subdivided
by biogeographic realm, such as nearctic,
southern ocean, Indo-Malayan, or
Afrotropical. Consultation with regional
experts, supplemented with extensive
literature reviews led to the identification
and evaluation of ecoregions. Ecoregion
boundaries are intended to encompass an
area within which important ecological and
evolutionary processes strongly interact.
Compared with the terrestrial realm, marine
ecoregions are considered to be more
dynamic ecological and biogeographic
units both spatially and temporally. Thus,
the ecoregion boundaries for the marine
environment were not as clearly defined.
Of the ecoregions identified, 238 were
considered to be globally outstanding in
terms of their biological distinctiveness and
were selected as the subset known as the
Global 200. The parameters used to define
biological distinctiveness were species
richness, endemism, higher taxonomic
uniqueness, extraordinary ecological or
evolutionary phenomena, and global rarity
of the major habitat type (Olson et al.
2000). Inclusion of ecoregions in the Global
200 based on these criteria estimates the
“urgency” for action in these areas based on
opportunities for conserving distinct units
around the world.
13
Although nine major habitat types were identified
for the marine realm, four were not assessed for
the Global 200 marine analysis: pelagic trades,
pelagic westerlies, abyssal, and hadal habitats.
These habitat types differed in scale from other
Global 200 ecoregions and have particularly
limited biodiversity information.
BIODIVERSITY – NEW ZEALAND’S MARINE ECOREGION ■ 81