Figure 2 The figure depicts temporal effects of network
structure on species diversity of communities. The trends about the
effects of the short network (blue line) and the nested network (red
line) on the alpha diversity (a), the gamma diversity (b), species
colonization (c) and species emigration (d) are given. The independent
sample T-test is used to test whether there are significant differences
in the effects of the two structures on the community attributes over
years. Note: *< 0.05, **< 0.01, ***<0.001.
The effects of short network and nested network on community species
diversity were significantly different in various scales. In terms of
the small-scale alpha diversity, although affected by abiotic factors,
the effects of the two kinds of networks basically showed an increasing
trend. Species richness in the nested network is always significantly
higher than that in the short network (in Fig. 2a). The nested network
was significantly more conducive to maintain of the alpha diversity
(\(T_{\text{test}}=-5.568,\ \ P<0.001\)).
For the large-scale gamma diversity, the community diversity increased
significantly over time under the regulation of nested network
(\(T_{\text{test}}=2.6075,\ \ P<0.005\), in Fig. 2b). Nested network
is more conducive to the colonization of new species at the later stage
of the experiment (in Fig. 2c). The effects of the two kinds of networks
on species emigration has no
significant rule, so the
environmental factor such as draught and precipitation maybe play more
role (in Fig. 2d).
3.2 Network structure affects species
attributes