Is there a relationship between socio-economic factors and biodiversity in urban ponds? A study in the city of Stockholm

Where economic parity meets ecology: Neither biodiversity nor ecosystem integrity values relate to wealth in the context of a medium-sized Finnish city

Ecological conditions are heavily influenced by human-environment interactions, which is why understanding the relationships between people and nature is crucial. While earlier studies have indicated a pattern of positive correlations between economic wealth and biodiversity in urban areas, there are some examples that suggest that such associations are more intricate than initially presumed. In this study, we aimed to assess whether such a relation holds in Lahti, a medium-sized city in southern Finland, considering two biodiversity proxies (i.e., bird and woody plant species richness) and the Urban Ecosystem Integrity Index (UEII) of the city. Our results show no clear relationship between economic wealth (average annual income per statistical area) reported for 2019 and the two assessed biodiversity proxies and the UEII. These findings shed new light on the "luxury effect" in urban areas and reveal the nature of such relationship in highly green cities embedded in economic parity scenarios.

Land uses in cities and their impacts on the water quality of urban freshwater blue spaces in the Pampean region (Argentina)

Freshwater blue spaces (FBS), such as ponds, are key elements of the urban landscape and are under strong anthropogenic pressure. Land-use types and diversity may exert a negative or positive impact on FBS' water quality depending on their nature and arrangement. The information available in this respect is remarkably scarcer for water bodies in the Global South than for the north. Thus, we aim to identify and quantify the land-use types in a 500-m buffer zone of urban ponds in the Pampean region (Argentina) to assess their impact on water quality. We based our study on 15 FBS located in neighborhoods of Buenos Aires province during cold and warm seasons. We analyzed physical, chemical, and biological variables, and estimated water conditions by means of water quality indexes (WQIs) and quality guidelines. We quantified the dominant land-use type and the diversity of uses in the ponds' buffer zones, and evaluated their relationships with WQIs. Our results showed that WQIs were negatively related to a high proportion of residential areas in the adjacent zone, while positively to recreational ones. The diversity of land uses did not influence the water quality. We propose a new WQI_pond with fewer key response variables, and as sensitive as the currently used WQI_objetive. We conclude that water quality from urban ponds in the Pampean region can be affected by dominant land-use type in the adjacent area but also the quality of their water supply sources (superficial and/or underground), clandestine wastewater discharges, and non-point pollution.

Biodiversity and socioeconomics in the city: a review of the luxury effect

The ecological dynamics of cities are influenced not only by geophysical and biological factors, but also by aspects of human society. In cities around the world, a pattern of higher biodiversity in affluent neighbourhoods has been termed ‘the luxury effect'. The luxury effect has been found globally regarding plant diversity and canopy or vegetative cover. Fewer studies have considered the luxury effect and animals, yet it has been recognized in the distributions of birds, bats, lizards and indoor arthropods. Higher socioeconomic status correlates with higher biodiversity resulting from many interacting factors—the creation and maintenance of green space on private and public lands, the tendency of both humans and other species to favour environmentally desirable areas, while avoiding environmental burdens, as well as enduring legacy effects. The luxury effect is amplified in arid cities and as neighbourhoods age, and reduced in tropical areas. Where the luxury effect exists, benefits of urban biodiversity are unequally distributed, particularly in low-income neighbourhoods with higher minority populations. The equal distribution of biodiversity in cities, and thus the elimination of the luxury effect, is a worthy societal goal.