Urban green roofs provide critical habitats for pollinators, but the quality of these artificial habitats can vary. Ecologist Dr. Hiroshi Sato and his team investigated how the diversity of flowering plant species on urban green roofs influences the nesting success of the solitary bee Osmia bicornis. Sato hypothesized that green roofs with a higher variety of native wildflower species would lead to higher nesting success—measured by the proportion of larvae that successfully develop into adults—because a diverse larval diet provides more balanced nutrition. To test this, the team monitored green roofs with varying levels of plant diversity and analyzed the nesting boxes placed there. Which choice, if true, would most directly support Sato's hypothesis?
- Nests on roofs containing a wide variety of native wildflowers yielded a significantly higher percentage of emerged adult bees than nests on roofs dominated by only one or two wildflower species.Answer
- BThe total number of solitary bee nests established on the green roofs was much higher in years with warm, dry spring weather than in years with cool, rainy weather.
- CSolitary bee species are generally more resilient to the challenges of urban environments than social bee species, such as honeybees.
- DAnalysis of the nests showed that Osmia bicornis larvae fed on a diverse diet even when the green roof contained only a small number of wildflower species.