Small green spaces making a big impact
It’s time to elevate the value of small green spaces. Up until recently, the prevailing view was that a larger green urban area was superior to numerous small spaces of greenery in supporting biodiversity. But new research is turning that view on its head. While large parks and greenery are important and should always be valued, the studies are pointing to how small green urban spaces are making a big impact.
As researchers from the University of Melbourne point out: ‘Small patches of green space can harbour significant biodiversity – even accounting for the challenges of fragmentation and edge effects.’ They continue: ‘Many studies have discovered that multiple small patches of equivalent area to a single large green space had greater species diversity.’ https://www.unimelb.edu.au/cities/projects/projects/current-projects/playbook-for-urban-biodiversity/plays/plays-at-state-and-national-scale2/s3.-remove-minimum-patch-size-rules-for-planning-schemes-and-vegetation
They argue that this contradicts mainstream understandings that small patches of green space are less valuable than larger green spaces, and call for a review of the regulations and policies that protect vegetation and open space.
A global analysis of 26 countries by Wintle et al. BA Wintle, et al., Global synthesis of conservation studies reveals the importance of small habitat patches for biodiversity. Proc Natl Acad Sci USA 116, 909–914 (2019). showed that many species would be lost if small, isolated patches of remnant habitat were ignored and conservation efforts were focused solely on large, intact, and highly connected areas.
The authors provide a number of reasons for often high levels of biodiversity in small green patches. First, in some heavily modified ecosystems, small patches are all that remains; no large patches exist. ‘Species endemic to these systems must either persist within the remaining small patches or not at all,’ they write. A second reason why small patches can be critical for biodiversity is the absence of key processes that drive species decline elsewhere.
Other pluses of small patches: they can act as stepping stones that promote connectivity in otherwise highly modified environments. And they can be nodal points for stimulating natural regeneration of modified ecosystems.
At PlantingSeeds, our extensive B&B Highway, now in over 220 locations, is a path of stepping stones for regeneration in the urban environment. With locations across New South Wales, Queensland, and Victoria (and with South Australia soon to join), we’re proud of the tangible differences we are making, creating corridors of learning and nature.
References
Fahrig, L. (2019). Habitat fragmentation: a long and tangled tale. Global Ecology and
Biogeography, 28(1), 33-41. https://doi.org/10.1111/geb.12839
Fahrig, L. (2020). Why do several small patches hold more species than few large patches?
Global Ecology and Biogeography, 29(4), 615-628. https://doi.org/10.1111/geb.13059
Kendal, D., Zeeman, B., Ikin, K., Lunt, I. D., McDonnell, M. J., Farrar, A., Pearce, L. M., &
Morgan, J. W. (2017). The importance of small urban reserves for plant conservation.
Biological Conservation, 213, 146-153. https://doi.org/10.1016/j.biocon.2017.07.007
Mumaw, L., & Bekessy, S. (2017). Wildlife gardening for collaborative public-private
biodiversity conservation. Australasian Journal of Environmental Management,
24(3), 1-19. https://doi.org/10.1080/14486563.2017.1309695