Final answer:
Species g is most likely to have a higher competitive effect on species f based on the per-capita competitive effect αfg, which only describes the impact of species g on species f without indicating the reverse effect.
Step-by-step explanation:
Based on the per-capita competitive effect of species g on species f, symbolized as αfg, it is most likely to suggest that species g has a higher competitive effect on species f. This parameter indicates how the presence of one individual of species g affects the ability of species f to exploit resources. The competitive effect can go both ways, but a given αfg value only describes the influence of species g on species f, not the reverse. Therefore, only the effect of species g on species f can be considered based on this value, not the other way around.
Intraspecific competition involves members of the same species competing, while interspecific competition involves members of different species competing for resources. When two species are in competition, the outcomes can range from local extinction of the less competitive species to specialization adaptations in both species to reduce competition -- known as resource partitioning. The possibility that species f affects species g is not given and thus cannot be determined from the given information of αfg alone.