What factor can negatively affect bee populations in urban environments?

High levels of pollution and chemical exposure are significant factors that can negatively affect bee populations in urban environments. Urban areas often have elevated levels of air and soil pollution due to various sources, including vehicle emissions and industrial activities. Chemicals such as pesticides and herbicides are commonly used in city landscaping and agriculture, leading to direct exposure for bees. These chemicals can be harmful or even lethal, impacting bee health and reducing their populations.

In contrast, the other factors mentioned, such as increased access to diverse plants, availability of fresh water, and presence of community gardens, generally contribute positively to bee populations. Diverse plants provide essential food sources through nectar and pollen, while fresh water is crucial for bees’ hydration and hive maintenance. Community gardens can create green spaces that support bee-friendly plants. Thus, while urban environments can pose challenges, pollution and chemical exposure stand out as particularly detrimental to bee health and survival.