Nicola Arndt und Matthias Pohl - Neobiota

The framework for the ecoregion map is based on the biogeographic realms of PIELOU (1979) and
UDVARDY (1975) and the modified biome systems of DINERSTEIN et al. (1995) and RICKETTS et al.
(1999) (Figure 1). All of these sources were used to delineate the extent of realms and biomes. These
include global maps of floristic or zoogeographic provinces (e.g., RÜBEL 1930; GLEASON &
CRONQUIST 1964; GOOD 1964), global and regional maps of units based on the distribution of selected
groups of plants and animals (e.g., HAGMEIER 1966), the world’s biotic province maps of DASMANN
(1973, 1974) and UDVARDY (1975), and global maps of broad vegetation types (e.g., UNESCO 1969;
DE LAUBENFELS 1975; SCHMITHÜSEN 1976). We then identified published regional classification
systems to be used as a baseline for ecoregion boundaries.
Ecoregions were based on widely recognized regional biogeographic systems in order to benefit from
the detailed analyses and long tradition of existing biogeographic work. For this reason, ecoregions
based on existing biogeographic maps are more finely resolved and better match actual patterns than
units modeled from different combinations of global-scale biophysical parameters. Having the
ecoregions closely match existing biogeographic systems should also help make the terrestrial
ecoregion map a more acceptable and useful tool for conservation planning in different regions. The
result of this approach is a globally comprehensive set of bioregional approximations that have been
stitched together. In some cases, one source became the basis for relatively large areas of the world,
including WHITE’s (1983) phytogeographic regions for the Afrotropics, THACKWAY & CRESSWELL’s
(1995) biogeographic regionalization for Australia, ZOHARY (1973) for Southwest Asia, MIYAWAKI
(1975) for Japan, and MACKINNON’s (1997) units (built upon DASMANN’s and UDVARDY’s biotic
provinces) for the Indo-Malayan ecoregions. In other cases, a combination of systems was required.
The Nearctic was built from the works of OMERNIK (1995), GALLANT et al. (1995), WIKEN et al.
(1989), and RZEDOWSKI (1978). The Neotropics were particularly complicated, and were developed
from the IBGE (1993) habitat classifications for Brazil, the vegetation maps of HUBER et al. (1988,
1995) for Venezuela and Guyana, and HOLDRIDGE’s life zones (1967, 1977) for Central America. The
ecoregions of Russia are adapted from KURNAEV (1990) and ISACHENKO et al. (1988), while the
Chinese ecoregions were developed from the work of the CHINESE VEGETATION MAP COMPILATION
COMMITTEE (1979) and the CHANGCHUN INSTITUTE OF GEOGRAPHY AND CHINESE ACADEMY OF
SCIENCES (1990). A key to the terrestrial ecoregions of the world map (Figure 2), the sources for
ecoregions, technical descriptions, and digital data, are available on the web site:
www.wwfus.org/science/ecoregions/ (OLSON et al. 2001). For every region, workshops, consultations,
and review by experts, as well as testing with newly available global data sets for the distribution of
some taxa, were very important in determining the final location, extent, and boundaries of ecoregions.
2 Delineating ecoregional boundaries worldwide
Most existing biogeographic systems required some degree of aggregation, subdivision, or boundary
modification so that, 1) there was a similar level of biogeographic resolution between units globally,
2) recognized biogeographic divisions were adequately reflected in each system, and 3) units and
boundaries match across adjacent systems. If widely accepted biogeographic maps were unavailable
for a particular region, we relied on landforms and vegetation to make calls on biotic divisions.
Montane and lowland habitats support distinct biotic communities and dynamics, and these were
separated where they occurred over extensive areas. Vegetation type was considered an important
indicator for plants and invertebrate communities.
73