Wealth does not buy richness: plant and soil bacterial diversity in temperate suburban yards are not influenced by income

Abstract Patterns of biodiversity in suburban areas have been increasingly linked to the behaviors and affluence of their residents. Residents of affluent neighborhoods tend to plant more flowering plant species and generally live in neighborhoods with cooler temperatures and more tree cover. These factors, among others, lead to increased plant, bird, arthropod, and lizard biodiversity in affluent neighborhoods. Here, we investigate whether this pattern exists in plant and soil bacterial communities in suburban yards in Raleigh, North Carolina. We surveyed the diversity of plants and soil bacteria across 30 homes, located in census block groups with median household incomes from $22,000 to $208,000. Overall, we detected 144 plant genera and 7,908 bacterial OTUs. Although we identified an indirect effect of household income on bacterial OTU richness, mediated by soil pH, household income was nevertheless a poor predictor of plant and soil bacterial diversity. The lack of a strong correlation between income and plant or bacterial diversity in our humid, subtropical study area is consistent with a broader literature suggesting that effects of affluence on biodiversity are most pronounced in arid climates.