Conceptually, this forced us to remove from the study those localities that belong to biomes represented by only one community in a biogeographic realm.
The number of included localities for cenogram method is: 97 (for global analysis), 15 (for Neotropic) and 32 (for Palaearctic) ** The double asterisk indicates that the number of biomes included in the Neotropics is also different in both methods, being the given biomes those for the BBS method, while for cenogram method are I, II, II/III and V CORRECTLY CLASSIFIED BIOGEOGRAPHIC REALM N COMMUNITIES (INCLUDED BIOMES) BSS CENOGRAMS GLOBAL 100 * 47.
However, our results were significantly improved when the analyses were repeated separating communities by biogeographic realms (Table 3), indicating a noteworthy influence of the evolutionary history on prey community structure based on their body size distributions.
While for cenogram global analysis are the slope variables (P5, P5-P1, G, W1 and WG) the principal ones that contribute to discriminate biomes, for the biogeographic realms analyses different variables contribute to separate biomes in every region.
The mayfly genus Heptagenia Walsh, 1863, (Insecta: Ephemeroptera: Heptageniidae) is distributed throughout the Holarctic biogeographic realm
and part of the Oriental realm, with twelve species currently recognized from North America (Webb et al.
If so, each biogeographic realm would be susceptible to invasion by species from the same biome type of other regions.
Or, the climate, soils, and other physical factors of each biogeographic realm may have some unique patterns of correlation to which local species are adapted and to which species from other realms must genetically adjust.
Imagine two different biogeographic realms, each with its own trade-off surface.
Mexico is the only country in the world where clear boundaries of two biogeographic realms
are found: Nearctic and Neotropic.
Situated, as it is, at the meeting place of the three Old World biogeographic realms
, the Arabian Peninsula has a wide species diversity, with representatives of all three realms breeding in the area.