As a media release sent out by the City of Cape Town last month explains, Cape Town lies within the greater Cape Floral region in which the rare Fynbos and Renosterveld vegetation groups are found. Although the City currently maintains 17 nature reserves and various conservation sites, these protected sites represent but a small percentage of the area where fynbos occurs across the city.
Hence the City’s ‘No Mowing Policy’.
At present, the City has 63 listed areas where mowing is suspended during the growing season which starts in July/August and ends in November, annually. These areas include public open spaces, greenbelts and road verges. This allows for annuals, perennials and geophytes to flower, mature and seed during spring. Someone who has an in-depth understanding of how campaigns like these contribute to conservation efforts is Peta Brom, an urban ecologist at the University of Cape Town’s (UCT) Department of Biological Sciences.
Brom says several botanists have recorded sensitive and endangered species of plants in road verges.
“The Grow, Don’t Mow campaign, will help us to identify the places where these grow and to develop better management strategies which will catch these occurrences,” she adds.
To understand how she came to this conclusion, a brief explanation of her research paper topic is required. Brom shares she was interested in how wild pollinators were responding to urban land-use patterns across a number of environmental gradients in the Cape context.
“Internationally, we know that some guilds of pollinators, particularly larger-bodied insects and cavity nesters, are thriving in cities because they are able to exploit the resources provided by gardeners.”
For her research purposes, Brom focused on monkey beetles. In 2018 and 2019, she surveyed them and the flower communities present in vacant lots and city parks, as well as some natural areas and farms for comparative purposes. “Over those two years, I visited 142 locations from almost all parts of the city during spring, which is when the beetles are active in their adult phase.”
Because she was documenting flowers, Brom noticed in 2018 that while contractors were sometimes mowing around the indigenous bulbs and daisies growing on road verges while they were in flower, they would return as soon as the plants stopped flowering. In other words, before the seeds would have had a chance to mature.
“This meant that there would be no follow-on population from the seed stock. For bulbs, the flowers return for a few more years; for the rapidly reseeding daisies, it often means that the patch is completely lost.”
In 2019 and 2020, Brom set up observation plots in nine parks: five in the northern suburbs and four in the southern suburbs. She monitored the phenology (observable phases of a life cycle) of the flowers from bud to seed-broadcast (mature seed) to determine how long to wait for the flowers to complete their reproductive cycle.
“The answer was that the main season concluded in mid-November, and the City has taken this on board. This year’s no-mow signage for designated parks says ‘flowering and seeding’. That’s a big win for urban biodiversity,” says Brom.
One of the biggest takeaways from her research is that urban landscapes are an under-researched opportunity for the management of biodiversity, but public buy-in will be essential in addressing this need.