Results
In small sytem, six scenarios started from one guild and the eleventh
habitat association were collapsed, because the environmental tolerance
of guild was nearly zero (< 0.0052). The results presented
here were based on 819 simulation outcomes.
Across scenarios, the number of guilds in system achieved first to a
stationary state; then, the species richness converged eventually to a
dynamical equilibrium through speciation-extinction balance. The number
of guilds achieved to a stationary state faster in higher dispersal
rates (Fig. 3).
In the model communities resulted with only one guild, the functional
uniqueness was zero; however, the relative portion explained by
environmental component in total explained variation was positively
biased in linear environmental gradient (Fig. 4a). The type I error of
pure environmental component was inflated in these scenarios. The
spatial and pure spatial components were always significant (Fig. 4b).
In the model communities resulted with more than two guilds, the
functional uniqueness and redundancy presented the opposite pattern
across ecological-evolutionary scales. The functional uniqueness
increased in an area packed within a biogeographic unit, that was
referred well by the relative portion explained by environmental
component in the total explained variation of overall model (Fig. 5a).
The power of pure environmental component increased in these scenarios.
The spatial and pure spatial components were always significant (Fig.
5b).
If the pure environmental component of overall model was significant,
the hierarchical guild structure and the spatial structures found within
and among patchy habitats were usually significant (Fig. 5b).
Furthermore, the total explained variation and the relative portions
explained by environmental and pure spatial components in total explaind
variation were similar between overall and hierarchical models; however,
the number of guilds coexisted in model communities was often larger
than the number of habitat types identified by the k -means
partitioning of linear combination scores (scaling 1) and simple
structure index criterion (Fig. 5a).
In the model communities resulted with only one guild, the Mantel
correlations of true spatial component approached to zero in an area
packed within a biogeographic unit (Fig. 6a). They were always
significant in an area encompassing independent biogeographic units, and
vanished only in some scenarios for an area packed within a
biogeographic unit (Fig. 6b). The Mantel correlations of false
environmental component also approached to zero in an area packed within
a biogeographic unit (Fig. 6a); however, they were often significant,
and did not control correctly the false detection in linear
environmental gradient (Fig. 6b).
In the model communities resulted with more than two guilds, the Mantel
correlations of true environmental component negatively departed in an
area packed within a biogeographic unit (Fig. 7a), and tended to emerge
the pattern of spatial autocorrelations (Fig. 7b). The Mantel
correlations of the spatial structures found by hierarchical model in
each environmental context were often significant (Fig. 7b).