A mowing strategy for urban parks to support spring flowers in a mediterranean climate city in South Africa

Abstract

Converting road verges and Public Open Space (POS) to floral-rich resources is an important strategy for supporting populations of urban pollinators. One of the ways this can be achieved is through adjusting mowing schedules, either with a “delayed start” after the end of winter, or a reduction in mowing frequency. In Mediterranean climate ecosystems with mild, wet winters, plant growth continues through the winter season and the definition of a “delayed start” is unclear. This study sought to identify a strategic period for the suspension of mowing activities in a city in South Africa with a Mediterranean climate. It estimated the duration of the flowering to seed-broadcast season of 20 species of native geophytes. Observations were made of phenological status from bud to seed broadcast in ten city parks in Cape Town during the austral spring flowering seasons of 2019 and 2020 (August – December). The Underhill and Zucchini (1988) Moult Model was employed to estimate the duration of the flowering season. Model results showed that mowing should stop in the second week of August and should not resume until the beginning of November in the study context. The results are discussed against the relative biodiversity contribution that different parks and verges make and the potential conflicts with the utility objectives of urban society.