Biodiversity in context: an analysis between urban areas and a forest reserve

Biological protection areas are a crucial refuge for biodiversity, especially due to the growing populations in cities. Generally, these areas are located far from urban centers in an attempt to avoid the effects of urbanization. However, does a reserve on the outskirts of the largest urban area in the Amazon also contribute to species conservation? Our research assessed the loss of aquatic macroinvertebrate biodiversity in streams of an urban area in development, adjacent to a biological protection area—the Ducke Reserve, a tropical rainforest reserve in the municipality of Manaus, AM - Brazil. We sampled 18 streams in the Ducke Reserve and 18 streams in the urban area. The communities between the urban area and Ducke Reserve showed no similarity (M2 = 0.917; correlation = 0.287; p = 0.423). A total of 107 taxa were found exclusively in the Ducke Reserve, while seven taxa were exclusive to the urban area of Manaus, with these seven being characteristic of disturbed environments. The low richness (w = 320; p = 0.001) and abundance (w = 242; p = 0.01) of macroinvertebrates in the urban area resulted in a 91% loss of diversity. Urbanization is a major driver of environmental change, affecting both aquatic and terrestrial ecosystems. Thus, we highlight that the Ducke Reserve plays a significant role in maintaining Manaus' biodiversity, and together with biological protection areas, represents our best hope for achieving global biodiversity conservation goals.