Final answer:
Increasing local diversity tends to increase the intercept of the species-area relationship because with more species per unit area, the baseline level of species richness is higher for a given area, reflecting a strong positive association between local diversity and the starting point of the species-area curve.
Step-by-step explanation:
Increasing local diversity tends to increase the intercept of the species-area relationship. The species-area relationship is a well-established ecological principle that captures the increase in species richness with increasing area surveyed. Local diversity, which refers to the number of species within a small, specific area, contributes to the overall species richness of a region. When local diversity increases, it suggests that there are many species per unit area, thus potentially raising the baseline level of species richness for a given area.
Empirical studies indicate that higher levels of local diversity may contribute to greater ecosystem resilience and productivity, as well as the potential to limit the impacts of invasive species. Moreover, local richness is typically proportionally less than regional richness but does not reach an asymptote; instead, it continues increasing with the size of the region being considered. As native diversity increases, it may potentially support the hypothesis of biotic resistance, where local assemblages are better able to resist invasions by non-native species.