Step 1: Understanding the Question:
The question asks for the scientist who introduced the concept of Alpha, Beta, and Gamma diversity to categorize biodiversity at different scales.
Detailed Explanation:
• R. H. Whittaker (1960): He was a pioneering American plant ecologist who proposed three levels of diversity to help compare biodiversity across different landscapes.
• Alpha ($\alpha$) Diversity: The diversity within a particular area or ecosystem, usually expressed as the number of species (species richness) in that specific location. It is the local scale.
• Beta ($\beta$) Diversity: The comparison of diversity between ecosystems, measured as the rate of change in species composition as one moves from one community to another.
• Gamma ($\gamma$) Diversity: The total species diversity in a large region (geographic scale), which is a product of alpha and beta diversity.
• Other scientists: A.G. Tansley (B) is famous for coining the term "Ecosystem" in 19
Step 2: Final Answer:
The term Alpha diversity was coined by R. H. Whittaker.