Hello again Westside Gardeners!
Most urban green spaces today are under intensive maintenance practices, including mowing and/or chemical inputs, among many other practices.
Much research on my side has me questioning the biodiversity potential of reduced-intensity maintenance regimes. However, evidence for a relationship between maintenance and biodiversity is still unclear and yet to be fully understood.
My research includes a complex association between maintenance and biodiversity, mainly dependent on the type of maintenance practice and the measurement of biodiversity. Mowing and heavy amounts of irrigation watering are the predominant maintenance practices that I studied, and evidence showed a negative association between mowing intensity and various aspects of plant diversity.
Similarly, reduced mowing intensity appeared to favour invertebrate diversity, yet I found mixed associations, as well as variations across taxonomic groups.
My studies with chemical input showed a negative association between the frequency of the use of herbicides, pesticides, insecticides and the diversity of plants, invertebrates and birds.
Nuanced findings, including a non-linear association between maintenance intensity and biodiversity and temporal geographical differences, are found within our Westside community. This would include parks, allotments, sports facilities, etc.
They have the potential to provide valuable habitats for flora and fauna species, depending on a range of factors such as their location, size, shape and maintenance. Here in the Westside, we have basin parks, basically an area to collect storm surface water. An area of open lawns and spotted tree plantings.
With watering saturation issues and intensive horticultural maintenance practices, which I have already mentioned, have negative environmental impacts such as habitat fragmentation and simplification, landscape homogenization and ecological degradation.
There is a growing interest in and advocacy for less intensive maintenance approaches for ecological considerations. The promotion of natural succession has been proposed to conserve and enhance biodiversity. Turning basin parks into infrequently mown lawns, “meadows” with flowering forbs, native grasses and riparian fauna. This would provide biodiversity, sustainability, aesthetics, educational and economic benefits.
Mark Koehler of Los Banos is an arborist and master gardener, who has degrees in Landscape Architecture and Landscape Horticulture from UC Berkeley and Northeastern University. Please send any questions or comments to markgardenguru@gmail.com.
