Data from: Complementing urban agriculture and green spaces is important for ecosystem functions and biodiversity in cities: A systematic review and meta-analysis

As cities expand, they encroach on agricultural land, impacting food
production and natural habitats. While urban agriculture could help
address these issues, the impact of increased food production on ecosystem
functions—particularly with regards to soil conservation, climate
regulation, and biodiversity—remains poorly understood. To fill this
knowledge gap, we conducted a meta-analysis to quantify the effects of
urban agriculture on ecosystem functions (i.e., soil quality and climate
regulation) and biodiversity (i.e., plants, birds, mammals, arthropods,
and insect pollinators). We estimated ecosystem functions and biodiversity
in urban agriculture by comparing them with other urban green spaces
(e.g., parks, residential gardens, green roofs) and conventional rural
farms. Our results overall showed that urban agriculture is in an
intermediate state between the other urban green spaces and conventional
rural farms in terms of environmental impacts. Urban agriculture had a
positive effect on the studied ecosystem functions relative to
conventional rural farms (+25%, CI95: +12% to +39%), but was equivalent in
its provision of these functions to other green spaces. Urban agriculture
also had a positive effect on biodiversity compared to conventional rural
farms (+38%, CI95: -10 to +111%), but a negative effect compared to green
spaces (-12%, CI95: -29 to +8%). Specifically, urban agriculture had 39%
(CI95: -59 to -10%) lower plant diversity and abundance than that seen in
other green spaces. Practical implications: Our results suggest that urban
agriculture's contribution to urban sustainability requires
complementarity with other green spaces to effectively support ecosystem
functions and biodiversity in cities. We also detected substantial issues
with the classification and characterisation of urban agriculture plots.
Improving conceptual and methodological consistency will continue to be a
crucial challenge for urban agriculture research.