The study explores the spatial variation in plant diversity across a large metropolitan area, focusing on the Central Arizona-Phoenix region. Using a probability-based survey and spatial statistical analyses, the researchers found that land use, distance from the urban center, elevation, family income, and housing age are significant factors influencing plant diversity. The results suggest a "luxury effect," where higher wealth is associated with greater plant diversity in urban landscapes. This relationship is robust and may be influenced by factors such as education, institutional control, and cultural values. The study highlights the complex interactions between human activities, socioeconomic conditions, and ecological processes in shaping urban plant communities.The study explores the spatial variation in plant diversity across a large metropolitan area, focusing on the Central Arizona-Phoenix region. Using a probability-based survey and spatial statistical analyses, the researchers found that land use, distance from the urban center, elevation, family income, and housing age are significant factors influencing plant diversity. The results suggest a "luxury effect," where higher wealth is associated with greater plant diversity in urban landscapes. This relationship is robust and may be influenced by factors such as education, institutional control, and cultural values. The study highlights the complex interactions between human activities, socioeconomic conditions, and ecological processes in shaping urban plant communities.