Answer :
Final answer:
The main difference between foundation and keystone species is that foundation species are usually the most abundant and key to the structure of an ecosystem, while keystone species have a disproportionate impact on the ecosystem's biodiversity and its maintenance but may not be abundant. So, the correct answer is option B. A foundation species is usually the most abundant, and a keystone species exerts the most influence on maintaining biodiversity.
Explanation:
Key Difference Between Foundation and Keystone Species
The key difference between a foundation species and a keystone species is primarily in their abundance and their impact on biodiversity within an ecosystem. A foundation species is usually the most abundant species and has the greatest influence on the overall structure of the ecosystem. They often are primary producers and are considered the base or bedrock of an ecosystem. An example of a foundation species is kelp, the species of brown algae forming the kelp forests off California.
In contrast, a keystone species, like the intertidal sea star Pisaster ochraceus or the banded tetra fish, may not be very abundant but has a disproportionate effect on maintaining biodiversity and ecological community's structure. The removal of a keystone species can lead to substantial changes in species composition and a reduction in biodiversity, indicating their crucial role despite not being the most abundant.
A foundation species is usually the most abundant, and a keystone species exerts the most influence on maintaining biodiversity.
