The two-way relationship between biodiversity and humanity is at the core of this journal’s scope. Ecosystems provide us with the majority of our needs, and we are the biggest influence within those ecosystems on their distribution and functioning. It therefore follows that socioeconomic factors will influence and be influenced by biodiversity. A current focus of research is the indirect effects of contemporary and historical injustices on species distributions and traits, particularly in urban areas1.

Two recent studies have examined the consequences of systemic racism for biodiversity within US cities. Redlining was an urban zoning policy that was in place from 1933 to 1968, under which areas were graded A to D according to how ‘safe’ they were perceived to be for real-estate investment. A and B areas had predominantly white populations and their grading subsequently led to greater investment, whereas C and D areas had a higher proportion of people of colour who were then excluded from these positive benefits. The structural inequities caused by redlining have persisted despite the end of the formal policy over 50 years ago. Writing in this issue of Nature Ecology & Evolution, Nelson-Olivieri et al. explore how urban noise levels are linked to past redlining and how noise influences wildlife. Using redlining grades combined with road, rail and aviation noise data from 83 US cities, the authors show that C and D areas are noisier than A and B ones in terms of both maximum volume of noise and spatial spread of noise. In a separate analysis, using data from the literature, they show that urban wildlife has a wide range of behavioural, physiological and population-level responses to noise. The behavioural responses include vocal calls, vigilance, foraging and mating, and the effects were particularly acute at the high noise levels most often found in redlined areas.

Writing in Nature Human Behaviour, Ellis-Soto et al. use data from 195 US cities to show that redlined districts are substantially underrepresented in terms of biodiversity data collection2. Over time, the amount of both community science and professional sampling of bird diversity is lower in C and D districts. Such differences in data availability are likely to lead to less interest and investment in conservation in these areas, exacerbating the inequities.

It is important to note that these studies leave gaps unfilled. Although Nelson-Olivieri et al. demonstrate links between redlining and noise and between noise and biodiversity, they do not directly show the link between redlining and biodiversity. Similarly, Ellis-Soto et al. show that redlining is associated with fewer biodiversity observations but they do not assess biodiversity per se. Nevertheless, the studies contribute to a growing body of evidence that shows that urban biodiversity is strongly influenced by social inequalities1. Access to green spaces and clean air is more limited in deprived areas, and the size and extent of private gardens can affect biodiversity indicators such as pollinator diversity3. Although much of this research has been conducted in the Global North, the importance of urban biodiversity is being championed in other regions — such as in Kano City, Nigeria, where a project to restore native tree species to the city aims to benefit households and wellbeing4.

The contributions of nature to human wellbeing makes social inequalities in proximity to and experience of nature particularly concerning. The concept of nature connectedness represents the emotional connection that is required to trigger the positive cycle of benefits between the wellbeing of humans and ecosystems5. A deeper understanding of this connection is explored in a recent study by Fisher et al.6 in Nature Sustainability. They apply a trait-based approach to get a granular picture of which species’ traits (for example, sound, colour or smell) are associated with which aspects of human wellbeing, and how much redundancy and complementarity there is between these traits. The majority of ecological traits they studied had positive effects on wellbeing, and when traits did have negative wellbeing effects a smaller number of species were involved. This suggests that there are many positive effects yet to be documented, whereas the negative effects are mostly known and therefore easier to manage. This kind of understanding could lead to more tailored approaches to biodiversity conservation and restoration in urban areas that take the needs of people into account.

Patterns of discrimination within cities is just one dimension of the human influence on biodiversity, and the studies discussed here add to a larger body of research on the long shadow of human history on the natural world. In particular, European colonialism has left a lasting mark on diversity in urban and rural areas around the world. The spread of alien species was facilitated by the expansion of European empires, and differences between those empires are detectable in the alien floras of today7. More broadly, the long-term dynamics of forest growth and carbon across multiple global regions have been governed by colonial history8 and the distribution of herbaria samples shows the imbalance between the Global North and South9.

It is increasingly clear that biodiversity patterns cannot be disentangled from broader socioeconomic and socioecological systems. In recognition of this systems-oriented lens, our new sister journal Nature Cities, which launches this month, will offer a forum for urban research across a broad range of disciplines.