Figure 4 Predicted changes in the strengths of intra- and
interspecific density dependence of Chthamalus dalli andGloiopeltis furcata depending on intrinsic growth rates. (a)
Strength of intraspecific density dependence of C. dalli(αCC). (b) Strength of intraspecific density dependence
of G. furcata (αGG). (c) Strength of
interspecific density dependence of C. dalli on G. furcata(αCG). (d) Strength of interspecific density dependence
of G. furcata on C. dalli (αGC). In (a)
and (c), the x -axis is the intrinsic growth rate of C.
dalli and the y -axis is the intrinsic growth rate of G.
furcata ; the axes in (b) and (d) are opposite. Yellow represents strong
and red represents weak intra- or interspecific density dependence. The
dashed lines in the figure show contours of the strength of density
dependence. Green dots indicate the environmental suitability of each
locality.
Table 1 Candidate models for each strength of intra- and
interspecific density dependence. rC andrG are the intrinsic growth rates ofChthamalus dalli and Gloiopeltis furcata , respectively.
Variables given as a function f (X) are spline functions; others
are linear variables. Interactions marked with × include all main
effects. Each model specification was used to model all parameters of
the strength of intra- and interspecific density dependence.