Intraspecific density dependence
For both αCC and αGG, the combination GAM was optimal (Table 2). Among the αGG candidate models, two had ΔAIC scores < 2 (Table 2).
For both C. dalli and G. furcata , while the strength of intraspecific density dependence decreased as their own intrinsic growth rate increased, the intrinsic growth rate of the opposite species exerted only a weak influence (Fig. 4a, b; Fig. S1, Supporting Information). For both species, the strength of intraspecific density dependence showed a similar trend in response to variations in the intrinsic growth rate. For αCC, the isoline interval decreased as rC increased (Fig. 4a), whereas for αGG the isoline interval was nearly uniform and parallel (Fig. 4b).