Urban Gardens Have Hidden Benefits
It has long been assumed that cultivating food leads to a loss of biodiversity and negative impacts on an ecosystem. But a new study published in Ecology Letters found that urban gardens are beneficial for biodiversity and good for humans. Researchers at multiple universities, including The University of Texas at Austin, rebut this assumption, showing that community gardens and urban farms positively affect biodiversity, local ecosystems and the well-being of humans that work in them. The study evaluated 28 urban community gardens across California over five years and quantified biodiversity in plant and animal life, as well as ecosystem functions such as pollination, carbon sequestration, food production, pest control and human well-being.
"We wanted to determine if there were any tradeoffs in terms of biodiversity or impacts on ecosystem function," says Shalene Jha, an associate professor of integrative biology and lead author of the paper. "What we found is that these gardens, which are providing tremendous nutritional resources and increasing well-being for gardeners, are also supporting incredibly high levels of plant and animal biodiversity. It's a win-win."
Previous assumptions by scientists about the negative effect of food production on biodiversity have been almost entirely based on intensive rural agriculture enterprises that tend to grow only one or two types of crops on a commercial scale. Urban community gardens, private gardens and urban farms and orchards tend to grow more types of plants in smaller areas. The new study is the first to explore the effects of urban gardens across a wide range of biodiversity measures and ecological services. It also found that the choices that gardeners make can have a large impact on their local ecosystem. Planting trees outside crop beds could increase carbon sequestration without limiting pollinators or decreasing food production from too much shade and mulching only within crop beds could help improve soil carbon services while avoiding negative effects on pest control and pollinators.
