Backyard Biodiversity: Urban Schoolyards Can Play an Important Role in Conservation

Muvengwi J, Kwenda A, Mbiba M, Mpindu T, The role of urban schools in biodiversity conservation across an urban landscape, Urban Forestry and Urban Greening (2019),



Biodiversity matters. Not just in the Amazon, but in your backyard, too. The recent report from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) took the world by storm; the biodiversity crisis is here, and plants and animals across the globe are facing extinction, ultimately transforming ecosystems as we know it. Since the report, there has been a public outcry about what we can do to slow the impending biodiversity crisis, covered everywhere from scientific journals to media outlets worldwide.

While there are many pathways to address the crisis, a paper from a team of African researchers published in Urban Forestry and Urban Greening points to the importance of addressing a big problem on a small scale, suggesting urban schoolyards can positively impact local biodiversity for both native and exotic species.

Why Schoolyards?

In urban areas, population growth has led to heightened development pressures and those pressures of urban development aren’t likely to disappear (Groom, 2006). More people live in cities than ever before and the urban population continues to rise globally (United Nations, 2018). African cities also have the highest predicted growth rates, making this study of notable importance (UN-Habitat, 2012).

Golf courses, urban gardens, and sidewalk greenery have been frequently studied for their role in urban ecology. Schoolyards have been frequently overlooked in urban ecology studies, despite being ubiquitous in cities around the world. This study examined biodiversity in Zimbabwean schoolyards across a density gradient, measured by the ratio between land area to human population. High density indicates high population and less land area, and low density is the opposite.

Harare Gardens in Zimbabwe. Credit: creative commons.
Measuring Diversity:

Schoolyards were selected across an urban gradient in Harare, Zimbabwe. In each yard the research team took note of trees and plants, logging which were native to the area or exotic. The results were analyzed by schoolyard size and suburb density, testing for difference in species density. Using various forms of diversity measures, the researchers measured both richness, the number of species, and abundance, the number of individuals per species, and Shannon diversity, which accounts for abundance and evenness of species.

Overall, the researchers found 125 tree species and 91 flower species across schoolyards in Harare. Indigenous tree species were the richest in medium density schoolyards, while tree diversity was lowest in high density suburbs. Diversity of flowers was different across suburbs.

Interestingly, the research team found high levels of exotic tree species in low density suburbs, hypothesizing this could be because native trees were replaced by exotics that grow rapidly (Blood et al., 2016).

The authors note many factors could be at play to explain what is physically present. Biodiversity in urban areas is driven by human behavior and socioeconomic status, and “luxury effect,” where exotic species are preferred as a status symbol (Hope et al., 2003).

Looking for biodiversity:

There’s no doubt about it; the biodiversity crisis is a big problem, threatening ecosystems from oceans to forests. Urban green spaces are often overlooked when we consider conservation, and schoolyards play an important and unassuming role in biodiversity, particularly in urban areas where these issues are of pressing concern.

In an op-ed for the Washington Post, journalist Gabriel Popkin spoke to the role of biodiversity in backyards, noting “too often we view the global biodiversity crisis as remote or abstract, involving the disappearance of exotic, charismatic megafauna such as tigers and elephants.” He goes on to argue that species loss occurs in our backyards and deserves our attention: “It’s often said that a society should be judged by how it treats its most vulnerable. A society could also be judged by how it cares for its trees. On both counts, we are falling far short.” Schoolyards could be a good place to start.




Blood, A., Starr, G., Escobedo, F., Chappelka, A., Staudhammer, C., 2016. How do urban forests compare? Tree diversity in urban and periurban forests of the southeastern US. Forests 7, 1- 15.

Groom, M.J., 2006. Threats to biodiversity. Princ. Conserv. Biol. 63-109

Hope, D., Gries, C., Zhu, W., Fagan, W.F., Redman, C.L., Grimm, N.B., Nels on, A.L., Martin, C., Kinzig, A., 2003. Socioeconomics drive urban plant diversity. Proc. Natl. Acad. Sci. 100, 339- 347. 0-387-73412-5_21.

IPBES. 2019. Global assessment report on biodiversity and ecosystem services of the Intergovernmental Science- Policy Platform on Biodiversity and Ecosystem Services. E. S. Brondizio, J. Settele, S. Díaz, and H. T. Ngo (editors). IPBES Secretariat, Bonn, Germany.

Muvengwi J, Kwenda A, Mbiba M, Mpindu T, The role of urban schools in biodiversity conservation across an urban landscape, Urban Forestry and Urban Greening (2019),

Plumer, Brad. “Humans Are Speeding Extinction and Altering the Natural World at an ‘Unprecedented’ Pace.” New York Times, 6 May 2019.

Popkin, Gabriel. “Want to Understand the Biodiversity Crisis? Look at the Trees in Your Backyard.” 23 May 2019.

UN Habitat, 2012. State of the world’s cities report 2012/2013 prosperities of cities. Nairobi, Kenya.

United Nations Department of Economic and Social Affairs, P.D., 2017. World Population Prospects The 2017 Revision Key Findings and Advance Tables. World Popul. Prospect. 2017 1-46.


reviewed by:

Kristen Brown

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Olivia Box

Olivia is interested in the areas where forest management, ecology, and natural history meet. At the University of Vermont, she is a masters student and she studies the effects of Asian Longhorn Beetle on forest communites. Throughout her masters, Olivia aspires to delve deeper into how forest management will evolve under the pressures of climate change, and to more effectively communicate her research to the public.

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