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. dalliCC). (b) Strength of intraspecific density dependence of G. furcataGG). (c) Strength of interspecific density dependence of C. dalli on G. furcataCG). (d) Strength of interspecific density dependence of G. furcata on C. dalliGC). 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.